ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted

make htmldocs fails with:

  Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301:
  ERROR: Unexpected indentation. [docutils]

The Return: section of ata_dsm_trim_pages() ends its first sentence with
a colon and continues with an indented bullet list. reStructuredText
requires a blank line before an indented block, so docutils chokes on
the list.

Simply adding the missing blank line does not work either: Return: is a
kernel-doc "special section", which is terminated by the first blank
line, so the bullet list would end up in the Description section,
detached from the sentence introducing it.

Spell the two bounds out as prose instead, so that the Return: section
stays self-contained. Documentation-only change.

Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND")
Reported-by: Thomas Huth <thuth@redhat.com>
Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

101 files changed, 16874 insertions, 0 deletions

diff --git a/samples/bpf/.gitignore b/samples/bpf/.gitignore
new file mode 100644
index 000000000..0002cd359
--- /dev/null
+++ b/samples/bpf/.gitignore
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: GPL-2.0-only
+cpustat
+fds_example
+hbm
+ibumad
+lathist
+lwt_len_hist
+map_perf_test
+offwaketime
+per_socket_stats_example
+sampleip
+sock_example
+sockex1
+sockex2
+sockex3
+spintest
+syscall_nrs.h
+syscall_tp
+task_fd_query
+tc_l2_redirect
+test_cgrp2_array_pin
+test_cgrp2_attach
+test_cgrp2_attach2
+test_cgrp2_sock
+test_cgrp2_sock2
+test_current_task_under_cgroup
+test_lru_dist
+test_map_in_map
+test_overhead
+test_probe_write_user
+trace_event
+trace_output
+tracex1
+tracex2
+tracex3
+tracex4
+tracex5
+tracex6
+tracex7
+xdp_adjust_tail
+xdp_fwd
+xdp_router_ipv4
+xdp_tx_iptunnel
+testfile.img
+hbm_out.log
+iperf.*
+*.out
+*.skel.h
+/vmlinux.h
+/bpftool/
+/libbpf/
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
new file mode 100644
index 000000000..95a4fa1f1
--- /dev/null
+++ b/samples/bpf/Makefile
@@ -0,0 +1,392 @@
+# SPDX-License-Identifier: GPL-2.0
+
+BPF_SAMPLES_PATH ?= $(abspath $(src))
+TOOLS_PATH := $(BPF_SAMPLES_PATH)/../../tools
+
+pound := \#
+
+# List of programs to build
+tprogs-y := test_lru_dist
+tprogs-y += sock_example
+tprogs-y += fds_example
+tprogs-y += sockex1
+tprogs-y += sockex2
+tprogs-y += sockex3
+tprogs-y += tracex1
+tprogs-y += tracex3
+tprogs-y += tracex4
+tprogs-y += tracex5
+tprogs-y += tracex6
+tprogs-y += trace_output
+tprogs-y += lathist
+tprogs-y += offwaketime
+tprogs-y += spintest
+tprogs-y += map_perf_test
+tprogs-y += xdp_router_ipv4
+tprogs-y += trace_event
+tprogs-y += sampleip
+tprogs-y += tc_l2_redirect
+tprogs-y += lwt_len_hist
+tprogs-y += xdp_tx_iptunnel
+tprogs-y += test_map_in_map
+tprogs-y += per_socket_stats_example
+tprogs-y += syscall_tp
+tprogs-y += cpustat
+tprogs-y += xdp_adjust_tail
+tprogs-y += xdp_fwd
+tprogs-y += task_fd_query
+tprogs-y += ibumad
+tprogs-y += hbm
+
+# Libbpf dependencies
+LIBBPF_SRC = $(TOOLS_PATH)/lib/bpf
+LIBBPF_OUTPUT = $(abspath $(BPF_SAMPLES_PATH))/libbpf
+LIBBPF_DESTDIR = $(LIBBPF_OUTPUT)
+LIBBPF_INCLUDE = $(LIBBPF_DESTDIR)/include
+LIBBPF = $(LIBBPF_OUTPUT)/libbpf.a
+
+CGROUP_HELPERS := ../../tools/testing/selftests/bpf/cgroup_helpers.o
+TRACE_HELPERS := ../../tools/testing/selftests/bpf/trace_helpers.o
+XDP_SAMPLE := xdp_sample_user.o
+
+fds_example-objs := fds_example.o
+sockex1-objs := sockex1_user.o
+sockex2-objs := sockex2_user.o
+sockex3-objs := sockex3_user.o
+tracex1-objs := tracex1_user.o $(TRACE_HELPERS)
+tracex3-objs := tracex3_user.o
+tracex4-objs := tracex4_user.o
+tracex5-objs := tracex5_user.o $(TRACE_HELPERS)
+tracex6-objs := tracex6_user.o
+trace_output-objs := trace_output_user.o
+lathist-objs := lathist_user.o
+offwaketime-objs := offwaketime_user.o $(TRACE_HELPERS)
+spintest-objs := spintest_user.o $(TRACE_HELPERS)
+map_perf_test-objs := map_perf_test_user.o
+test_overhead-objs := test_overhead_user.o
+trace_event-objs := trace_event_user.o $(TRACE_HELPERS)
+sampleip-objs := sampleip_user.o $(TRACE_HELPERS)
+tc_l2_redirect-objs := tc_l2_redirect_user.o
+lwt_len_hist-objs := lwt_len_hist_user.o
+xdp_tx_iptunnel-objs := xdp_tx_iptunnel_user.o
+test_map_in_map-objs := test_map_in_map_user.o
+per_socket_stats_example-objs := cookie_uid_helper_example.o
+syscall_tp-objs := syscall_tp_user.o
+cpustat-objs := cpustat_user.o
+xdp_adjust_tail-objs := xdp_adjust_tail_user.o
+xdp_fwd-objs := xdp_fwd_user.o
+task_fd_query-objs := task_fd_query_user.o $(TRACE_HELPERS)
+ibumad-objs := ibumad_user.o
+hbm-objs := hbm.o $(CGROUP_HELPERS)
+
+xdp_router_ipv4-objs := xdp_router_ipv4_user.o $(XDP_SAMPLE)
+
+# Tell kbuild to always build the programs
+always-y := $(tprogs-y)
+always-y += sockex1_kern.o
+always-y += sockex2_kern.o
+always-y += sockex3_kern.o
+always-y += tracex1.bpf.o
+always-y += tracex3.bpf.o
+always-y += tracex4.bpf.o
+always-y += tracex5.bpf.o
+always-y += tracex6.bpf.o
+always-y += trace_output.bpf.o
+always-y += tcbpf1_kern.o
+always-y += tc_l2_redirect_kern.o
+always-y += lathist_kern.o
+always-y += offwaketime.bpf.o
+always-y += spintest.bpf.o
+always-y += map_perf_test.bpf.o
+always-y += parse_varlen.o parse_simple.o parse_ldabs.o
+always-y += trace_event_kern.o
+always-y += sampleip_kern.o
+always-y += lwt_len_hist.bpf.o
+always-y += xdp_tx_iptunnel_kern.o
+always-y += test_map_in_map.bpf.o
+always-y += tcp_synrto_kern.o
+always-y += tcp_rwnd_kern.o
+always-y += tcp_bufs_kern.o
+always-y += tcp_cong_kern.o
+always-y += tcp_iw_kern.o
+always-y += tcp_clamp_kern.o
+always-y += tcp_basertt_kern.o
+always-y += tcp_tos_reflect_kern.o
+always-y += tcp_dumpstats_kern.o
+always-y += xdp2skb_meta_kern.o
+always-y += syscall_tp_kern.o
+always-y += cpustat_kern.o
+always-y += xdp_adjust_tail_kern.o
+always-y += xdp_fwd_kern.o
+always-y += task_fd_query_kern.o
+always-y += ibumad_kern.o
+always-y += hbm_out_kern.o
+always-y += hbm_edt_kern.o
+
+COMMON_CFLAGS = $(TPROGS_USER_CFLAGS)
+TPROGS_LDFLAGS = $(TPROGS_USER_LDFLAGS)
+
+ifeq ($(ARCH), arm)
+# Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux
+# headers when arm instruction set identification is requested.
+ARM_ARCH_SELECTOR := $(filter -D__LINUX_ARM_ARCH__%, $(KBUILD_CFLAGS))
+BPF_EXTRA_CFLAGS := $(ARM_ARCH_SELECTOR)
+TPROGS_CFLAGS += $(ARM_ARCH_SELECTOR)
+endif
+
+ifeq ($(ARCH), mips)
+TPROGS_CFLAGS += -D__SANE_USERSPACE_TYPES__
+ifdef CONFIG_MACH_LOONGSON64
+BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-loongson64
+BPF_EXTRA_CFLAGS += -I$(srctree)/arch/mips/include/asm/mach-generic
+endif
+endif
+
+ifeq ($(ARCH), x86)
+BPF_EXTRA_CFLAGS += -fcf-protection
+endif
+
+COMMON_CFLAGS += -Wall -O2
+COMMON_CFLAGS += -Wmissing-prototypes
+COMMON_CFLAGS += -Wstrict-prototypes
+COMMON_CFLAGS += $(call try-run,\
+	printf "int main() { return 0; }" |\
+	$(CC) -Werror -fsanitize=bounds -x c - -o "$$TMP",-fsanitize=bounds,)
+
+TPROGS_CFLAGS += $(COMMON_CFLAGS)
+TPROGS_CFLAGS += -I$(objtree)/usr/include
+TPROGS_CFLAGS += -I$(srctree)/tools/testing/selftests/bpf/
+TPROGS_CFLAGS += -I$(LIBBPF_INCLUDE)
+TPROGS_CFLAGS += -I$(srctree)/tools/include
+TPROGS_CFLAGS += -I$(srctree)/tools/perf
+TPROGS_CFLAGS += -I$(srctree)/tools/lib
+TPROGS_CFLAGS += -DHAVE_ATTR_TEST=0
+
+ifdef SYSROOT
+COMMON_CFLAGS += --sysroot=$(SYSROOT)
+TPROGS_LDFLAGS := -L$(SYSROOT)/usr/lib
+endif
+
+TPROGS_LDLIBS			+= $(LIBBPF) -lelf -lz
+TPROGLDLIBS_xdp_router_ipv4	+= -lm -pthread
+TPROGLDLIBS_tracex4		+= -lrt
+TPROGLDLIBS_trace_output	+= -lrt
+TPROGLDLIBS_map_perf_test	+= -lrt
+
+# Allows pointing LLC/CLANG to a LLVM backend with bpf support, redefine on cmdline:
+# make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
+LLC ?= llc
+CLANG ?= clang
+OPT ?= opt
+LLVM_DIS ?= llvm-dis
+LLVM_OBJCOPY ?= llvm-objcopy
+LLVM_READELF ?= llvm-readelf
+BTF_PAHOLE ?= pahole
+
+# Detect that we're cross compiling and use the cross compiler
+ifdef CROSS_COMPILE
+CLANG_ARCH_ARGS = --target=$(notdir $(CROSS_COMPILE:%-=%))
+endif
+
+# Don't evaluate probes and warnings if we need to run make recursively
+ifneq ($(src),)
+HDR_PROBE := $(shell printf "$(pound)include <linux/types.h>\n struct list_head { int a; }; int main() { return 0; }" | \
+	$(CC) $(TPROGS_CFLAGS) $(TPROGS_LDFLAGS) -x c - \
+	-o /dev/null 2>/dev/null && echo okay)
+
+ifeq ($(HDR_PROBE),)
+$(warning WARNING: Detected possible issues with include path.)
+$(warning WARNING: Please install kernel headers locally (make headers_install).)
+endif
+
+BTF_LLC_PROBE := $(shell $(LLC) -march=bpf -mattr=help 2>&1 | grep dwarfris)
+BTF_PAHOLE_PROBE := $(shell $(BTF_PAHOLE) --help 2>&1 | grep BTF)
+BTF_OBJCOPY_PROBE := $(shell $(LLVM_OBJCOPY) --help 2>&1 | grep -i 'usage.*llvm')
+BTF_LLVM_PROBE := $(shell echo "int main() { return 0; }" | \
+			  $(CLANG) --target=bpf -O2 -g -c -x c - -o ./llvm_btf_verify.o; \
+			  $(LLVM_READELF) -S ./llvm_btf_verify.o | grep BTF; \
+			  /bin/rm -f ./llvm_btf_verify.o)
+
+BPF_EXTRA_CFLAGS += -fno-stack-protector
+ifneq ($(BTF_LLVM_PROBE),)
+	BPF_EXTRA_CFLAGS += -g
+else
+ifneq ($(and $(BTF_LLC_PROBE),$(BTF_PAHOLE_PROBE),$(BTF_OBJCOPY_PROBE)),)
+	BPF_EXTRA_CFLAGS += -g
+	LLC_FLAGS += -mattr=dwarfris
+	DWARF2BTF = y
+endif
+endif
+endif
+
+# Trick to allow make to be run from this directory
+all:
+	$(MAKE) -C ../../ M=$(CURDIR) BPF_SAMPLES_PATH=$(CURDIR)
+
+clean:
+	$(MAKE) -C ../../ M=$(CURDIR) clean
+	@find $(CURDIR) -type f -name '*~' -delete
+	@$(RM) -r $(CURDIR)/libbpf $(CURDIR)/bpftool
+
+$(LIBBPF): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(LIBBPF_OUTPUT)
+# Fix up variables inherited from Kbuild that tools/ build system won't like
+	$(MAKE) -C $(LIBBPF_SRC) RM='rm -rf' EXTRA_CFLAGS="$(COMMON_CFLAGS)" \
+		LDFLAGS="$(TPROGS_LDFLAGS)" srctree=$(BPF_SAMPLES_PATH)/../../ \
+		O= OUTPUT=$(LIBBPF_OUTPUT)/ DESTDIR=$(LIBBPF_DESTDIR) prefix= \
+		$@ install_headers
+
+BPFTOOLDIR := $(TOOLS_PATH)/bpf/bpftool
+BPFTOOL_OUTPUT := $(abspath $(BPF_SAMPLES_PATH))/bpftool
+DEFAULT_BPFTOOL := $(BPFTOOL_OUTPUT)/bootstrap/bpftool
+BPFTOOL ?= $(DEFAULT_BPFTOOL)
+$(DEFAULT_BPFTOOL): $(wildcard $(BPFTOOLDIR)/*.[ch] $(BPFTOOLDIR)/Makefile) | $(BPFTOOL_OUTPUT)
+	$(MAKE) -C $(BPFTOOLDIR) srctree=$(BPF_SAMPLES_PATH)/../../ 		\
+		OUTPUT=$(BPFTOOL_OUTPUT)/ bootstrap
+
+$(LIBBPF_OUTPUT) $(BPFTOOL_OUTPUT):
+	$(call msg,MKDIR,$@)
+	$(Q)mkdir -p $@
+
+$(obj)/syscall_nrs.h:	$(obj)/syscall_nrs.s FORCE
+	$(call filechk,offsets,__SYSCALL_NRS_H__)
+
+targets += syscall_nrs.s
+clean-files += syscall_nrs.h
+
+FORCE:
+
+
+# Verify LLVM compiler tools are available and bpf target is supported by llc
+.PHONY: verify_cmds verify_target_bpf $(CLANG) $(LLC)
+
+verify_cmds: $(CLANG) $(LLC)
+	@for TOOL in $^ ; do \
+		if ! (which -- "$${TOOL}" > /dev/null 2>&1); then \
+			echo "*** ERROR: Cannot find LLVM tool $${TOOL}" ;\
+			exit 1; \
+		else true; fi; \
+	done
+
+verify_target_bpf: verify_cmds
+	@if ! (${LLC} -march=bpf -mattr=help > /dev/null 2>&1); then \
+		echo "*** ERROR: LLVM (${LLC}) does not support 'bpf' target" ;\
+		echo "   NOTICE: LLVM version >= 3.7.1 required" ;\
+		exit 2; \
+	else true; fi
+
+$(BPF_SAMPLES_PATH)/*.c: verify_target_bpf $(LIBBPF)
+$(src)/*.c: verify_target_bpf $(LIBBPF)
+
+libbpf_hdrs: $(LIBBPF)
+$(obj)/$(TRACE_HELPERS) $(obj)/$(CGROUP_HELPERS) $(obj)/$(XDP_SAMPLE): | libbpf_hdrs
+
+.PHONY: libbpf_hdrs
+
+$(obj)/xdp_router_ipv4_user.o: $(obj)/xdp_router_ipv4.skel.h
+
+$(obj)/tracex5.bpf.o: $(obj)/syscall_nrs.h
+$(obj)/hbm_out_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
+$(obj)/hbm.o: $(src)/hbm.h
+$(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
+
+# Override includes for xdp_sample_user.o because $(srctree)/usr/include in
+# TPROGS_CFLAGS causes conflicts
+XDP_SAMPLE_CFLAGS += -Wall -O2 \
+		     -I$(src)/../../tools/include \
+		     -I$(src)/../../tools/include/uapi \
+		     -I$(LIBBPF_INCLUDE) \
+		     -I$(src)/../../tools/testing/selftests/bpf
+
+$(obj)/$(XDP_SAMPLE): TPROGS_CFLAGS = $(XDP_SAMPLE_CFLAGS) $(TPROGS_USER_CFLAGS)
+$(obj)/$(XDP_SAMPLE): $(src)/xdp_sample_user.h $(src)/xdp_sample_shared.h
+# Override includes for trace_helpers.o because __must_check won't be defined
+# in our include path.
+$(obj)/$(TRACE_HELPERS): TPROGS_CFLAGS := $(TPROGS_CFLAGS) -D__must_check=
+
+-include $(BPF_SAMPLES_PATH)/Makefile.target
+
+VMLINUX_BTF_PATHS ?= $(abspath $(if $(O),$(O)/vmlinux))				\
+		     $(abspath $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux))	\
+		     $(abspath $(objtree)/vmlinux)
+VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
+
+$(obj)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
+ifeq ($(VMLINUX_H),)
+ifeq ($(VMLINUX_BTF),)
+	$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)",\
+		build the kernel or set VMLINUX_BTF like "VMLINUX_BTF=/sys/kernel/btf/vmlinux" or VMLINUX_H variable)
+endif
+	$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
+else
+	$(Q)cp "$(VMLINUX_H)" $@
+endif
+
+clean-files += vmlinux.h
+
+# Get Clang's default includes on this system, as opposed to those seen by
+# '--target=bpf'. This fixes "missing" files on some architectures/distros,
+# such as asm/byteorder.h, asm/socket.h, asm/sockios.h, sys/cdefs.h etc.
+#
+# Use '-idirafter': Don't interfere with include mechanics except where the
+# build would have failed anyways.
+define get_sys_includes
+$(shell $(1) -v -E - </dev/null 2>&1 \
+        | sed -n '/<...> search starts here:/,/End of search list./{ s| \(/.*\)|-idirafter \1|p }') \
+$(shell $(1) -dM -E - </dev/null | grep '#define __riscv_xlen ' | sed 's/#define /-D/' | sed 's/ /=/')
+endef
+
+CLANG_SYS_INCLUDES = $(call get_sys_includes,$(CLANG))
+
+$(obj)/xdp_router_ipv4.bpf.o: $(obj)/xdp_sample.bpf.o
+
+$(obj)/%.bpf.o: $(src)/%.bpf.c $(obj)/vmlinux.h $(src)/xdp_sample.bpf.h $(src)/xdp_sample_shared.h
+	@echo "  CLANG-BPF " $@
+	$(Q)$(CLANG) -g -O2 --target=bpf -D__TARGET_ARCH_$(SRCARCH) \
+		-Wno-compare-distinct-pointer-types -I$(srctree)/include \
+		-I$(srctree)/samples/bpf -I$(srctree)/tools/include \
+		-I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES) \
+		-c $(filter %.bpf.c,$^) -o $@
+
+LINKED_SKELS := xdp_router_ipv4.skel.h
+clean-files += $(LINKED_SKELS)
+
+xdp_router_ipv4.skel.h-deps := xdp_router_ipv4.bpf.o xdp_sample.bpf.o
+
+LINKED_BPF_SRCS := $(patsubst %.bpf.o,%.bpf.c,$(foreach skel,$(LINKED_SKELS),$($(skel)-deps)))
+
+BPF_SRCS_LINKED := $(notdir $(wildcard $(src)/*.bpf.c))
+BPF_OBJS_LINKED := $(patsubst %.bpf.c,$(obj)/%.bpf.o, $(BPF_SRCS_LINKED))
+BPF_SKELS_LINKED := $(addprefix $(obj)/,$(LINKED_SKELS))
+
+$(BPF_SKELS_LINKED): $(BPF_OBJS_LINKED) $(BPFTOOL)
+	@echo "  BPF GEN-OBJ " $(@:.skel.h=)
+	$(Q)$(BPFTOOL) gen object $(@:.skel.h=.lbpf.o) $(addprefix $(obj)/,$($(@F)-deps))
+	@echo "  BPF GEN-SKEL" $(@:.skel.h=)
+	$(Q)$(BPFTOOL) gen skeleton $(@:.skel.h=.lbpf.o) name $(notdir $(@:.skel.h=)) > $@
+
+# asm/sysreg.h - inline assembly used by it is incompatible with llvm.
+# But, there is no easy way to fix it, so just exclude it since it is
+# useless for BPF samples.
+# below we use long chain of commands, clang | opt | llvm-dis | llc,
+# to generate final object file. 'clang' compiles the source into IR
+# with native target, e.g., x64, arm64, etc. 'opt' does bpf CORE IR builtin
+# processing (llvm12) and IR optimizations. 'llvm-dis' converts
+# 'opt' output to IR, and finally 'llc' generates bpf byte code.
+$(obj)/%.o: $(src)/%.c
+	@echo "  CLANG-bpf " $@
+	$(Q)$(CLANG) $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(BPF_EXTRA_CFLAGS) \
+		-I$(obj) -I$(srctree)/tools/testing/selftests/bpf/ \
+		-I$(LIBBPF_INCLUDE) $(CLANG_SYS_INCLUDES) \
+		-D__KERNEL__ -D__BPF_TRACING__ -Wno-unused-value -Wno-pointer-sign \
+		-D__TARGET_ARCH_$(SRCARCH) -Wno-compare-distinct-pointer-types \
+		-Wno-gnu-variable-sized-type-not-at-end \
+		-Wno-address-of-packed-member -Wno-tautological-compare \
+		-Wno-unknown-warning-option $(CLANG_ARCH_ARGS) \
+		-fno-asynchronous-unwind-tables \
+		-I$(srctree)/samples/bpf/ -include asm_goto_workaround.h \
+		-O2 -emit-llvm -Xclang -disable-llvm-passes -c $< -o - | \
+		$(OPT) -O2 -mtriple=bpf-pc-linux | $(LLVM_DIS) | \
+		$(LLC) -march=bpf $(LLC_FLAGS) -filetype=obj -o $@
+ifeq ($(DWARF2BTF),y)
+	$(BTF_PAHOLE) -J $@
+endif
diff --git a/samples/bpf/Makefile.target b/samples/bpf/Makefile.target
new file mode 100644
index 000000000..7621f55e2
--- /dev/null
+++ b/samples/bpf/Makefile.target
@@ -0,0 +1,75 @@
+# SPDX-License-Identifier: GPL-2.0
+# ==========================================================================
+# Building binaries on the host system
+# Binaries are not used during the compilation of the kernel, and intended
+# to be build for target board, target board can be host of course. Added to
+# build binaries to run not on host system.
+#
+# Sample syntax
+# tprogs-y := xsk_example
+# Will compile xsk_example.c and create an executable named xsk_example
+#
+# tprogs-y    := xdpsock
+# xdpsock-objs := xdpsock_1.o xdpsock_2.o
+# Will compile xdpsock_1.c and xdpsock_2.c, and then link the executable
+# xdpsock, based on xdpsock_1.o and xdpsock_2.o
+#
+# Derived from scripts/Makefile.host
+#
+__tprogs := $(sort $(tprogs-y))
+
+# C code
+# Executables compiled from a single .c file
+tprog-csingle	:= $(foreach m,$(__tprogs), \
+			$(if $($(m)-objs),,$(m)))
+
+# C executables linked based on several .o files
+tprog-cmulti	:= $(foreach m,$(__tprogs),\
+			$(if $($(m)-objs),$(m)))
+
+# Object (.o) files compiled from .c files
+tprog-cobjs	:= $(sort $(foreach m,$(__tprogs),$($(m)-objs)))
+
+tprog-csingle	:= $(addprefix $(obj)/,$(tprog-csingle))
+tprog-cmulti	:= $(addprefix $(obj)/,$(tprog-cmulti))
+tprog-cobjs	:= $(addprefix $(obj)/,$(tprog-cobjs))
+
+#####
+# Handle options to gcc. Support building with separate output directory
+
+_tprogc_flags   = $(TPROGS_CFLAGS) \
+                 $(TPROGCFLAGS_$(basetarget).o)
+
+# $(objtree)/$(obj) for including generated headers from checkin source files
+ifeq ($(KBUILD_EXTMOD),)
+ifdef building_out_of_srctree
+_tprogc_flags   += -I $(objtree)/$(obj)
+endif
+endif
+
+tprogc_flags    = -Wp,-MD,$(depfile) $(_tprogc_flags)
+
+# Create executable from a single .c file
+# tprog-csingle -> Executable
+quiet_cmd_tprog-csingle 	= CC  $@
+      cmd_tprog-csingle	= $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ $< \
+		$(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F))
+$(tprog-csingle): $(obj)/%: $(src)/%.c FORCE
+	$(call if_changed_dep,tprog-csingle)
+
+# Link an executable based on list of .o files, all plain c
+# tprog-cmulti -> executable
+quiet_cmd_tprog-cmulti	= LD  $@
+      cmd_tprog-cmulti	= $(CC) $(tprogc_flags) $(TPROGS_LDFLAGS) -o $@ \
+			  $(addprefix $(obj)/,$($(@F)-objs)) \
+			  $(TPROGS_LDLIBS) $(TPROGLDLIBS_$(@F))
+$(tprog-cmulti): $(tprog-cobjs) FORCE
+	$(call if_changed,tprog-cmulti)
+$(call multi_depend, $(tprog-cmulti), , -objs)
+
+# Create .o file from a single .c file
+# tprog-cobjs -> .o
+quiet_cmd_tprog-cobjs	= CC  $@
+      cmd_tprog-cobjs	= $(CC) $(tprogc_flags) -c -o $@ $<
+$(tprog-cobjs): $(obj)/%.o: $(src)/%.c FORCE
+	$(call if_changed_dep,tprog-cobjs)
diff --git a/samples/bpf/README.rst b/samples/bpf/README.rst
new file mode 100644
index 000000000..cabe2d216
--- /dev/null
+++ b/samples/bpf/README.rst
@@ -0,0 +1,121 @@
+eBPF sample programs
+====================
+
+This directory contains a test stubs, verifier test-suite and examples
+for using eBPF. The examples use libbpf from tools/lib/bpf.
+
+Note that the XDP-specific samples have been removed from this directory and
+moved to the xdp-tools repository: https://github.com/xdp-project/xdp-tools
+See the commit messages removing each tool from this directory for how to
+convert specific command invocations between the old samples and the utilities
+in xdp-tools.
+
+Build dependencies
+==================
+
+Compiling requires having installed:
+ * clang
+ * llvm
+ * pahole
+
+Consult :ref:`Documentation/process/changes.rst <changes>` for the minimum
+version numbers required and how to update them. Note that LLVM's tool
+'llc' must support target 'bpf', list version and supported targets with
+command: ``llc --version``
+
+Clean and configuration
+-----------------------
+
+It can be needed to clean tools, samples or kernel before trying new arch or
+after some changes (on demand)::
+
+ make -C tools clean
+ make -C samples/bpf clean
+ make clean
+
+Configure kernel, defconfig for instance
+(see "tools/testing/selftests/bpf/config" for a reference config)::
+
+ make defconfig
+
+Kernel headers
+--------------
+
+There are usually dependencies to header files of the current kernel.
+To avoid installing devel kernel headers system wide, as a normal
+user, simply call::
+
+ make headers_install
+
+This will create a local "usr/include" directory in the git/build top
+level directory, that the make system will automatically pick up first.
+
+Compiling
+=========
+
+For building the BPF samples, issue the below command from the kernel
+top level directory::
+
+ make M=samples/bpf
+
+It is also possible to call make from this directory.  This will just
+hide the invocation of make as above.
+
+Manually compiling LLVM with 'bpf' support
+------------------------------------------
+
+Since version 3.7.0, LLVM adds a proper LLVM backend target for the
+BPF bytecode architecture.
+
+By default llvm will build all non-experimental backends including bpf.
+To generate a smaller llc binary one can use::
+
+ -DLLVM_TARGETS_TO_BUILD="BPF"
+
+We recommend that developers who want the fastest incremental builds
+use the Ninja build system, you can find it in your system's package
+manager, usually the package is ninja or ninja-build.
+
+Quick sniplet for manually compiling LLVM and clang
+(build dependencies are ninja, cmake and gcc-c++)::
+
+ $ git clone https://github.com/llvm/llvm-project.git
+ $ mkdir -p llvm-project/llvm/build
+ $ cd llvm-project/llvm/build
+ $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
+            -DLLVM_ENABLE_PROJECTS="clang"    \
+            -DCMAKE_BUILD_TYPE=Release        \
+            -DLLVM_BUILD_RUNTIME=OFF
+ $ ninja
+
+It is also possible to point make to the newly compiled 'llc' or
+'clang' command via redefining LLC or CLANG on the make command line::
+
+ make M=samples/bpf LLC=~/git/llvm-project/llvm/build/bin/llc CLANG=~/git/llvm-project/llvm/build/bin/clang
+
+Cross compiling samples
+-----------------------
+In order to cross-compile, say for arm64 targets, export CROSS_COMPILE and ARCH
+environment variables before calling make. But do this before clean,
+configuration and header install steps described above. This will direct make to
+build samples for the cross target::
+
+ export ARCH=arm64
+ export CROSS_COMPILE="aarch64-linux-gnu-"
+
+Headers can be also installed on RFS of target board if need to keep them in
+sync (not necessarily and it creates a local "usr/include" directory also)::
+
+ make INSTALL_HDR_PATH=~/some_sysroot/usr headers_install
+
+Pointing LLC and CLANG is not necessarily if it's installed on HOST and have
+in its targets appropriate arm64 arch (usually it has several arches).
+Build samples::
+
+ make M=samples/bpf
+
+Or build samples with SYSROOT if some header or library is absent in toolchain,
+say libelf, providing address to file system containing headers and libs,
+can be RFS of target board::
+
+ make M=samples/bpf SYSROOT=~/some_sysroot
diff --git a/samples/bpf/asm_goto_workaround.h b/samples/bpf/asm_goto_workaround.h
new file mode 100644
index 000000000..634e81d83
--- /dev/null
+++ b/samples/bpf/asm_goto_workaround.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2019 Facebook */
+#ifndef __ASM_GOTO_WORKAROUND_H
+#define __ASM_GOTO_WORKAROUND_H
+
+/*
+ * This will bring in asm_goto_output and asm_inline macro definitions
+ * if enabled by compiler and config options.
+ */
+#include <linux/types.h>
+
+#ifdef asm_goto_output
+#undef asm_goto_output
+#define asm_goto_output(x...) asm volatile("invalid use of asm_goto_output")
+#endif
+
+/*
+ * asm_inline is defined as asm __inline in "include/linux/compiler_types.h"
+ * if supported by the kernel's CC (i.e CONFIG_CC_HAS_ASM_INLINE) which is not
+ * supported by CLANG.
+ */
+#ifdef asm_inline
+#undef asm_inline
+#define asm_inline asm
+#endif
+
+#define volatile(x...) volatile("")
+#endif
diff --git a/samples/bpf/bpf_insn.h b/samples/bpf/bpf_insn.h
new file mode 100644
index 000000000..29c3bb6ad
--- /dev/null
+++ b/samples/bpf/bpf_insn.h
@@ -0,0 +1,233 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/* eBPF instruction mini library */
+#ifndef __BPF_INSN_H
+#define __BPF_INSN_H
+
+struct bpf_insn;
+
+/* ALU ops on registers, bpf_add|sub|...: dst_reg += src_reg */
+
+#define BPF_ALU64_REG(OP, DST, SRC)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_X,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+#define BPF_ALU32_REG(OP, DST, SRC)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU | BPF_OP(OP) | BPF_X,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+/* ALU ops on immediates, bpf_add|sub|...: dst_reg += imm32 */
+
+#define BPF_ALU64_IMM(OP, DST, IMM)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU64 | BPF_OP(OP) | BPF_K,	\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+#define BPF_ALU32_IMM(OP, DST, IMM)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU | BPF_OP(OP) | BPF_K,		\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+/* Short form of mov, dst_reg = src_reg */
+
+#define BPF_MOV64_REG(DST, SRC)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU64 | BPF_MOV | BPF_X,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+#define BPF_MOV32_REG(DST, SRC)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU | BPF_MOV | BPF_X,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+/* Short form of mov, dst_reg = imm32 */
+
+#define BPF_MOV64_IMM(DST, IMM)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU64 | BPF_MOV | BPF_K,		\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+#define BPF_MOV32_IMM(DST, IMM)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_ALU | BPF_MOV | BPF_K,		\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+/* BPF_LD_IMM64 macro encodes single 'load 64-bit immediate' insn */
+#define BPF_LD_IMM64(DST, IMM)					\
+	BPF_LD_IMM64_RAW(DST, 0, IMM)
+
+#define BPF_LD_IMM64_RAW(DST, SRC, IMM)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_LD | BPF_DW | BPF_IMM,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = 0,					\
+		.imm   = (__u32) (IMM) }),			\
+	((struct bpf_insn) {					\
+		.code  = 0, /* zero is reserved opcode */	\
+		.dst_reg = 0,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = ((__u64) (IMM)) >> 32 })
+
+#ifndef BPF_PSEUDO_MAP_FD
+# define BPF_PSEUDO_MAP_FD	1
+#endif
+
+/* pseudo BPF_LD_IMM64 insn used to refer to process-local map_fd */
+#define BPF_LD_MAP_FD(DST, MAP_FD)				\
+	BPF_LD_IMM64_RAW(DST, BPF_PSEUDO_MAP_FD, MAP_FD)
+
+
+/* Direct packet access, R0 = *(uint *) (skb->data + imm32) */
+
+#define BPF_LD_ABS(SIZE, IMM)					\
+	((struct bpf_insn) {					\
+		.code  = BPF_LD | BPF_SIZE(SIZE) | BPF_ABS,	\
+		.dst_reg = 0,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = IMM })
+
+/* Memory load, dst_reg = *(uint *) (src_reg + off16) */
+
+#define BPF_LDX_MEM(SIZE, DST, SRC, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_LDX | BPF_SIZE(SIZE) | BPF_MEM,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = 0 })
+
+/* Memory store, *(uint *) (dst_reg + off16) = src_reg */
+
+#define BPF_STX_MEM(SIZE, DST, SRC, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_MEM,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = 0 })
+
+/*
+ * Atomic operations:
+ *
+ *   BPF_ADD                  *(uint *) (dst_reg + off16) += src_reg
+ *   BPF_AND                  *(uint *) (dst_reg + off16) &= src_reg
+ *   BPF_OR                   *(uint *) (dst_reg + off16) |= src_reg
+ *   BPF_XOR                  *(uint *) (dst_reg + off16) ^= src_reg
+ *   BPF_ADD | BPF_FETCH      src_reg = atomic_fetch_add(dst_reg + off16, src_reg);
+ *   BPF_AND | BPF_FETCH      src_reg = atomic_fetch_and(dst_reg + off16, src_reg);
+ *   BPF_OR | BPF_FETCH       src_reg = atomic_fetch_or(dst_reg + off16, src_reg);
+ *   BPF_XOR | BPF_FETCH      src_reg = atomic_fetch_xor(dst_reg + off16, src_reg);
+ *   BPF_XCHG                 src_reg = atomic_xchg(dst_reg + off16, src_reg)
+ *   BPF_CMPXCHG              r0 = atomic_cmpxchg(dst_reg + off16, r0, src_reg)
+ */
+
+#define BPF_ATOMIC_OP(SIZE, OP, DST, SRC, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_STX | BPF_SIZE(SIZE) | BPF_ATOMIC,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = OP })
+
+/* Legacy alias */
+#define BPF_STX_XADD(SIZE, DST, SRC, OFF) BPF_ATOMIC_OP(SIZE, BPF_ADD, DST, SRC, OFF)
+
+/* Memory store, *(uint *) (dst_reg + off16) = imm32 */
+
+#define BPF_ST_MEM(SIZE, DST, OFF, IMM)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_ST | BPF_SIZE(SIZE) | BPF_MEM,	\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = OFF,					\
+		.imm   = IMM })
+
+/* Conditional jumps against registers, if (dst_reg 'op' src_reg) goto pc + off16 */
+
+#define BPF_JMP_REG(OP, DST, SRC, OFF)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP | BPF_OP(OP) | BPF_X,		\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = 0 })
+
+/* Like BPF_JMP_REG, but with 32-bit wide operands for comparison. */
+
+#define BPF_JMP32_REG(OP, DST, SRC, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_X,	\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = 0 })
+
+/* Conditional jumps against immediates, if (dst_reg 'op' imm32) goto pc + off16 */
+
+#define BPF_JMP_IMM(OP, DST, IMM, OFF)				\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP | BPF_OP(OP) | BPF_K,		\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = OFF,					\
+		.imm   = IMM })
+
+/* Like BPF_JMP_IMM, but with 32-bit wide operands for comparison. */
+
+#define BPF_JMP32_IMM(OP, DST, IMM, OFF)			\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP32 | BPF_OP(OP) | BPF_K,	\
+		.dst_reg = DST,					\
+		.src_reg = 0,					\
+		.off   = OFF,					\
+		.imm   = IMM })
+
+/* Raw code statement block */
+
+#define BPF_RAW_INSN(CODE, DST, SRC, OFF, IMM)			\
+	((struct bpf_insn) {					\
+		.code  = CODE,					\
+		.dst_reg = DST,					\
+		.src_reg = SRC,					\
+		.off   = OFF,					\
+		.imm   = IMM })
+
+/* Program exit */
+
+#define BPF_EXIT_INSN()						\
+	((struct bpf_insn) {					\
+		.code  = BPF_JMP | BPF_EXIT,			\
+		.dst_reg = 0,					\
+		.src_reg = 0,					\
+		.off   = 0,					\
+		.imm   = 0 })
+
+#endif
diff --git a/samples/bpf/cookie_uid_helper_example.c b/samples/bpf/cookie_uid_helper_example.c
new file mode 100644
index 000000000..f0df3dda4
--- /dev/null
+++ b/samples/bpf/cookie_uid_helper_example.c
@@ -0,0 +1,332 @@
+/* This test is a demo of using get_socket_uid and get_socket_cookie
+ * helper function to do per socket based network traffic monitoring.
+ * It requires iptables version higher then 1.6.1. to load pinned eBPF
+ * program into the xt_bpf match.
+ *
+ * TEST:
+ * ./run_cookie_uid_helper_example.sh -option
+ * option:
+ *	-t: do traffic monitoring test, the program will continuously
+ * print out network traffic happens after program started A sample
+ * output is shown below:
+ *
+ * cookie: 877, uid: 0x3e8, Pakcet Count: 20, Bytes Count: 11058
+ * cookie: 132, uid: 0x0, Pakcet Count: 2, Bytes Count: 286
+ * cookie: 812, uid: 0x3e8, Pakcet Count: 3, Bytes Count: 1726
+ * cookie: 802, uid: 0x3e8, Pakcet Count: 2, Bytes Count: 104
+ * cookie: 877, uid: 0x3e8, Pakcet Count: 20, Bytes Count: 11058
+ * cookie: 831, uid: 0x3e8, Pakcet Count: 2, Bytes Count: 104
+ * cookie: 0, uid: 0x0, Pakcet Count: 6, Bytes Count: 712
+ * cookie: 880, uid: 0xfffe, Pakcet Count: 1, Bytes Count: 70
+ *
+ *	-s: do getsockopt SO_COOKIE test, the program will set up a pair of
+ * UDP sockets and send packets between them. And read out the traffic data
+ * directly from the ebpf map based on the socket cookie.
+ *
+ * Clean up: if using shell script, the script file will delete the iptables
+ * rule and unmount the bpf program when exit. Else the iptables rule need
+ * to be deleted by hand, see run_cookie_uid_helper_example.sh for detail.
+ */
+
+#define _GNU_SOURCE
+
+#define offsetof(type, member)	__builtin_offsetof(type, member)
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <error.h>
+#include <limits.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <net/if.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include "bpf_insn.h"
+
+#define PORT 8888
+
+struct stats {
+	uint32_t uid;
+	uint64_t packets;
+	uint64_t bytes;
+};
+
+static int map_fd, prog_fd;
+
+static bool test_finish;
+
+static void maps_create(void)
+{
+	map_fd = bpf_map_create(BPF_MAP_TYPE_HASH, NULL, sizeof(uint32_t),
+				sizeof(struct stats), 100, NULL);
+	if (map_fd < 0)
+		error(1, errno, "map create failed!\n");
+}
+
+static void prog_load(void)
+{
+	static char log_buf[1 << 16];
+
+	struct bpf_insn prog[] = {
+		/*
+		 * Save sk_buff for future usage. value stored in R6 to R10 will
+		 * not be reset after a bpf helper function call.
+		 */
+		BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+		/*
+		 * pc1: BPF_FUNC_get_socket_cookie takes one parameter,
+		 * R1: sk_buff
+		 */
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				BPF_FUNC_get_socket_cookie),
+		/* pc2-4: save &socketCookie to r7 for future usage*/
+		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0, -8),
+		BPF_MOV64_REG(BPF_REG_7, BPF_REG_10),
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_7, -8),
+		/*
+		 * pc5-8: set up the registers for BPF_FUNC_map_lookup_elem,
+		 * it takes two parameters (R1: map_fd,  R2: &socket_cookie)
+		 */
+		BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+		BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				BPF_FUNC_map_lookup_elem),
+		/*
+		 * pc9. if r0 != 0x0, go to pc+14, since we have the cookie
+		 * stored already
+		 * Otherwise do pc10-22 to setup a new data entry.
+		 */
+		BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 14),
+		BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				BPF_FUNC_get_socket_uid),
+		/*
+		 * Place a struct stats in the R10 stack and sequentially
+		 * place the member value into the memory. Packets value
+		 * is set by directly place a IMM value 1 into the stack.
+		 */
+		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_0,
+			    -32 + (__s16)offsetof(struct stats, uid)),
+		BPF_ST_MEM(BPF_DW, BPF_REG_10,
+			   -32 + (__s16)offsetof(struct stats, packets), 1),
+		/*
+		 * __sk_buff is a special struct used for eBPF program to
+		 * directly access some sk_buff field.
+		 */
+		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6,
+				offsetof(struct __sk_buff, len)),
+		BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_1,
+			    -32 + (__s16)offsetof(struct stats, bytes)),
+		/*
+		 * add new map entry using BPF_FUNC_map_update_elem, it takes
+		 * 4 parameters (R1: map_fd, R2: &socket_cookie, R3: &stats,
+		 * R4: flags)
+		 */
+		BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+		BPF_MOV64_REG(BPF_REG_2, BPF_REG_7),
+		BPF_MOV64_REG(BPF_REG_3, BPF_REG_10),
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_3, -32),
+		BPF_MOV64_IMM(BPF_REG_4, 0),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
+				BPF_FUNC_map_update_elem),
+		BPF_JMP_IMM(BPF_JA, 0, 0, 5),
+		/*
+		 * pc24-30 update the packet info to a exist data entry, it can
+		 * be done by directly write to pointers instead of using
+		 * BPF_FUNC_map_update_elem helper function
+		 */
+		BPF_MOV64_REG(BPF_REG_9, BPF_REG_0),
+		BPF_MOV64_IMM(BPF_REG_1, 1),
+		BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_9, BPF_REG_1,
+			      offsetof(struct stats, packets)),
+		BPF_LDX_MEM(BPF_W, BPF_REG_1, BPF_REG_6,
+				offsetof(struct __sk_buff, len)),
+		BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_9, BPF_REG_1,
+			      offsetof(struct stats, bytes)),
+		BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_6,
+				offsetof(struct __sk_buff, len)),
+		BPF_EXIT_INSN(),
+	};
+	LIBBPF_OPTS(bpf_prog_load_opts, opts,
+		.log_buf = log_buf,
+		.log_size = sizeof(log_buf),
+	);
+
+	prog_fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL",
+				prog, ARRAY_SIZE(prog), &opts);
+	if (prog_fd < 0)
+		error(1, errno, "failed to load prog\n%s\n", log_buf);
+}
+
+static void prog_attach_iptables(char *file)
+{
+	int ret;
+	char rules[256];
+
+	if (bpf_obj_pin(prog_fd, file))
+		error(1, errno, "bpf_obj_pin");
+	if (strlen(file) > 50) {
+		printf("file path too long: %s\n", file);
+		exit(1);
+	}
+	ret = snprintf(rules, sizeof(rules),
+		       "iptables -A OUTPUT -m bpf --object-pinned %s -j ACCEPT",
+		       file);
+	if (ret < 0 || ret >= sizeof(rules)) {
+		printf("error constructing iptables command\n");
+		exit(1);
+	}
+	ret = system(rules);
+	if (ret < 0) {
+		printf("iptables rule update failed: %d/n", WEXITSTATUS(ret));
+		exit(1);
+	}
+}
+
+static void print_table(void)
+{
+	struct stats curEntry;
+	uint32_t curN = UINT32_MAX;
+	uint32_t nextN;
+	int res;
+
+	while (bpf_map_get_next_key(map_fd, &curN, &nextN) > -1) {
+		curN = nextN;
+		res = bpf_map_lookup_elem(map_fd, &curN, &curEntry);
+		if (res < 0) {
+			error(1, errno, "fail to get entry value of Key: %u\n",
+				curN);
+		} else {
+			printf("cookie: %u, uid: 0x%x, Packet Count: %lu,"
+				" Bytes Count: %lu\n", curN, curEntry.uid,
+				curEntry.packets, curEntry.bytes);
+		}
+	}
+}
+
+static void udp_client(void)
+{
+	struct sockaddr_in si_other = {0};
+	struct sockaddr_in si_me = {0};
+	struct stats dataEntry;
+	int s_rcv, s_send, i, recv_len;
+	char message = 'a';
+	char buf;
+	uint64_t cookie;
+	int res;
+	socklen_t cookie_len = sizeof(cookie);
+	socklen_t slen = sizeof(si_other);
+
+	s_rcv = socket(PF_INET, SOCK_DGRAM, 0);
+	if (s_rcv < 0)
+		error(1, errno, "rcv socket creat failed!\n");
+	si_other.sin_family = AF_INET;
+	si_other.sin_port = htons(PORT);
+	if (inet_aton("127.0.0.1", &si_other.sin_addr) == 0)
+		error(1, errno, "inet_aton\n");
+	if (bind(s_rcv, (struct sockaddr *)&si_other, sizeof(si_other)) == -1)
+		error(1, errno, "bind\n");
+	s_send = socket(PF_INET, SOCK_DGRAM, 0);
+	if (s_send < 0)
+		error(1, errno, "send socket creat failed!\n");
+	res = getsockopt(s_send, SOL_SOCKET, SO_COOKIE, &cookie, &cookie_len);
+	if (res < 0)
+		printf("get cookie failed: %s\n", strerror(errno));
+	res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry);
+	if (res != -1)
+		error(1, errno, "socket stat found while flow not active\n");
+	for (i = 0; i < 10; i++) {
+		res = sendto(s_send, &message, sizeof(message), 0,
+			     (struct sockaddr *)&si_other, slen);
+		if (res == -1)
+			error(1, errno, "send\n");
+		if (res != sizeof(message))
+			error(1, 0, "%uB != %luB\n", res, sizeof(message));
+		recv_len = recvfrom(s_rcv, &buf, sizeof(buf), 0,
+			     (struct sockaddr *)&si_me, &slen);
+		if (recv_len < 0)
+			error(1, errno, "receive\n");
+		res = memcmp(&(si_other.sin_addr), &(si_me.sin_addr),
+			   sizeof(si_me.sin_addr));
+		if (res != 0)
+			error(1, EFAULT, "sender addr error: %d\n", res);
+		printf("Message received: %c\n", buf);
+		res = bpf_map_lookup_elem(map_fd, &cookie, &dataEntry);
+		if (res < 0)
+			error(1, errno, "lookup sk stat failed, cookie: %lu\n",
+			      cookie);
+		printf("cookie: %lu, uid: 0x%x, Packet Count: %lu,"
+			" Bytes Count: %lu\n\n", cookie, dataEntry.uid,
+			dataEntry.packets, dataEntry.bytes);
+	}
+	close(s_send);
+	close(s_rcv);
+}
+
+static int usage(void)
+{
+	printf("Usage: ./run_cookie_uid_helper_example.sh"
+		" bpfObjName -option\n"
+		"	-t	traffic monitor test\n"
+		"	-s	getsockopt cookie test\n");
+	return 1;
+}
+
+static void finish(int ret)
+{
+	test_finish = true;
+}
+
+int main(int argc, char *argv[])
+{
+	int opt;
+	bool cfg_test_traffic = false;
+	bool cfg_test_cookie = false;
+
+	if (argc != 3)
+		return usage();
+	while ((opt = getopt(argc, argv, "ts")) != -1) {
+		switch (opt) {
+		case 't':
+			cfg_test_traffic = true;
+			break;
+		case 's':
+			cfg_test_cookie = true;
+			break;
+
+		default:
+			printf("unknown option %c\n", opt);
+			usage();
+			return -1;
+		}
+	}
+	maps_create();
+	prog_load();
+	prog_attach_iptables(argv[2]);
+	if (cfg_test_traffic) {
+		if (signal(SIGINT, finish) == SIG_ERR)
+			error(1, errno, "register SIGINT handler failed");
+		if (signal(SIGTERM, finish) == SIG_ERR)
+			error(1, errno, "register SIGTERM handler failed");
+		while (!test_finish) {
+			print_table();
+			printf("\n");
+			sleep(1);
+		}
+	} else if (cfg_test_cookie) {
+		udp_client();
+	}
+	close(prog_fd);
+	close(map_fd);
+	return 0;
+}
diff --git a/samples/bpf/cpustat_kern.c b/samples/bpf/cpustat_kern.c
new file mode 100644
index 000000000..7ec7143e2
--- /dev/null
+++ b/samples/bpf/cpustat_kern.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+/*
+ * The CPU number, cstate number and pstate number are based
+ * on 96boards Hikey with octa CA53 CPUs.
+ *
+ * Every CPU have three idle states for cstate:
+ *   WFI, CPU_OFF, CLUSTER_OFF
+ *
+ * Every CPU have 5 operating points:
+ *   208MHz, 432MHz, 729MHz, 960MHz, 1200MHz
+ *
+ * This code is based on these assumption and other platforms
+ * need to adjust these definitions.
+ */
+#define MAX_CPU			8
+#define MAX_PSTATE_ENTRIES	5
+#define MAX_CSTATE_ENTRIES	3
+
+static int cpu_opps[] = { 208000, 432000, 729000, 960000, 1200000 };
+
+/*
+ * my_map structure is used to record cstate and pstate index and
+ * timestamp (Idx, Ts), when new event incoming we need to update
+ * combination for new state index and timestamp (Idx`, Ts`).
+ *
+ * Based on (Idx, Ts) and (Idx`, Ts`) we can calculate the time
+ * interval for the previous state: Duration(Idx) = Ts` - Ts.
+ *
+ * Every CPU has one below array for recording state index and
+ * timestamp, and record for cstate and pstate saperately:
+ *
+ * +--------------------------+
+ * | cstate timestamp         |
+ * +--------------------------+
+ * | cstate index             |
+ * +--------------------------+
+ * | pstate timestamp         |
+ * +--------------------------+
+ * | pstate index             |
+ * +--------------------------+
+ */
+#define MAP_OFF_CSTATE_TIME	0
+#define MAP_OFF_CSTATE_IDX	1
+#define MAP_OFF_PSTATE_TIME	2
+#define MAP_OFF_PSTATE_IDX	3
+#define MAP_OFF_NUM		4
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, MAX_CPU * MAP_OFF_NUM);
+} my_map SEC(".maps");
+
+/* cstate_duration records duration time for every idle state per CPU */
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, MAX_CPU * MAX_CSTATE_ENTRIES);
+} cstate_duration SEC(".maps");
+
+/* pstate_duration records duration time for every operating point per CPU */
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, MAX_CPU * MAX_PSTATE_ENTRIES);
+} pstate_duration SEC(".maps");
+
+/*
+ * The trace events for cpu_idle and cpu_frequency are taken from:
+ * /sys/kernel/tracing/events/power/cpu_idle/format
+ * /sys/kernel/tracing/events/power/cpu_frequency/format
+ *
+ * These two events have same format, so define one common structure.
+ */
+struct cpu_args {
+	u64 pad;
+	u32 state;
+	u32 cpu_id;
+};
+
+/* calculate pstate index, returns MAX_PSTATE_ENTRIES for failure */
+static u32 find_cpu_pstate_idx(u32 frequency)
+{
+	u32 i;
+
+	for (i = 0; i < sizeof(cpu_opps) / sizeof(u32); i++) {
+		if (frequency == cpu_opps[i])
+			return i;
+	}
+
+	return i;
+}
+
+SEC("tracepoint/power/cpu_idle")
+int bpf_prog1(struct cpu_args *ctx)
+{
+	u64 *cts, *pts, *cstate, *pstate, prev_state, cur_ts, delta;
+	u32 key, cpu, pstate_idx;
+	u64 *val;
+
+	if (ctx->cpu_id > MAX_CPU)
+		return 0;
+
+	cpu = ctx->cpu_id;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_CSTATE_TIME;
+	cts = bpf_map_lookup_elem(&my_map, &key);
+	if (!cts)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_CSTATE_IDX;
+	cstate = bpf_map_lookup_elem(&my_map, &key);
+	if (!cstate)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_TIME;
+	pts = bpf_map_lookup_elem(&my_map, &key);
+	if (!pts)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_IDX;
+	pstate = bpf_map_lookup_elem(&my_map, &key);
+	if (!pstate)
+		return 0;
+
+	prev_state = *cstate;
+	*cstate = ctx->state;
+
+	if (!*cts) {
+		*cts = bpf_ktime_get_ns();
+		return 0;
+	}
+
+	cur_ts = bpf_ktime_get_ns();
+	delta = cur_ts - *cts;
+	*cts = cur_ts;
+
+	/*
+	 * When state doesn't equal to (u32)-1, the cpu will enter
+	 * one idle state; for this case we need to record interval
+	 * for the pstate.
+	 *
+	 *                 OPP2
+	 *            +---------------------+
+	 *     OPP1   |                     |
+	 *   ---------+                     |
+	 *                                  |  Idle state
+	 *                                  +---------------
+	 *
+	 *            |<- pstate duration ->|
+	 *            ^                     ^
+	 *           pts                  cur_ts
+	 */
+	if (ctx->state != (u32)-1) {
+
+		/* record pstate after have first cpu_frequency event */
+		if (!*pts)
+			return 0;
+
+		delta = cur_ts - *pts;
+
+		pstate_idx = find_cpu_pstate_idx(*pstate);
+		if (pstate_idx >= MAX_PSTATE_ENTRIES)
+			return 0;
+
+		key = cpu * MAX_PSTATE_ENTRIES + pstate_idx;
+		val = bpf_map_lookup_elem(&pstate_duration, &key);
+		if (val)
+			__sync_fetch_and_add((long *)val, delta);
+
+	/*
+	 * When state equal to (u32)-1, the cpu just exits from one
+	 * specific idle state; for this case we need to record
+	 * interval for the pstate.
+	 *
+	 *       OPP2
+	 *   -----------+
+	 *              |                          OPP1
+	 *              |                     +-----------
+	 *              |     Idle state      |
+	 *              +---------------------+
+	 *
+	 *              |<- cstate duration ->|
+	 *              ^                     ^
+	 *             cts                  cur_ts
+	 */
+	} else {
+
+		key = cpu * MAX_CSTATE_ENTRIES + prev_state;
+		val = bpf_map_lookup_elem(&cstate_duration, &key);
+		if (val)
+			__sync_fetch_and_add((long *)val, delta);
+	}
+
+	/* Update timestamp for pstate as new start time */
+	if (*pts)
+		*pts = cur_ts;
+
+	return 0;
+}
+
+SEC("tracepoint/power/cpu_frequency")
+int bpf_prog2(struct cpu_args *ctx)
+{
+	u64 *pts, *cstate, *pstate, cur_ts, delta;
+	u32 key, cpu, pstate_idx;
+	u64 *val;
+
+	cpu = ctx->cpu_id;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_TIME;
+	pts = bpf_map_lookup_elem(&my_map, &key);
+	if (!pts)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_PSTATE_IDX;
+	pstate = bpf_map_lookup_elem(&my_map, &key);
+	if (!pstate)
+		return 0;
+
+	key = cpu * MAP_OFF_NUM + MAP_OFF_CSTATE_IDX;
+	cstate = bpf_map_lookup_elem(&my_map, &key);
+	if (!cstate)
+		return 0;
+
+	*pstate = ctx->state;
+
+	if (!*pts) {
+		*pts = bpf_ktime_get_ns();
+		return 0;
+	}
+
+	cur_ts = bpf_ktime_get_ns();
+	delta = cur_ts - *pts;
+	*pts = cur_ts;
+
+	/* When CPU is in idle, bail out to skip pstate statistics */
+	if (*cstate != (u32)(-1))
+		return 0;
+
+	/*
+	 * The cpu changes to another different OPP (in below diagram
+	 * change frequency from OPP3 to OPP1), need recording interval
+	 * for previous frequency OPP3 and update timestamp as start
+	 * time for new frequency OPP1.
+	 *
+	 *                 OPP3
+	 *            +---------------------+
+	 *     OPP2   |                     |
+	 *   ---------+                     |
+	 *                                  |    OPP1
+	 *                                  +---------------
+	 *
+	 *            |<- pstate duration ->|
+	 *            ^                     ^
+	 *           pts                  cur_ts
+	 */
+	pstate_idx = find_cpu_pstate_idx(*pstate);
+	if (pstate_idx >= MAX_PSTATE_ENTRIES)
+		return 0;
+
+	key = cpu * MAX_PSTATE_ENTRIES + pstate_idx;
+	val = bpf_map_lookup_elem(&pstate_duration, &key);
+	if (val)
+		__sync_fetch_and_add((long *)val, delta);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/cpustat_user.c b/samples/bpf/cpustat_user.c
new file mode 100644
index 000000000..356f756cb
--- /dev/null
+++ b/samples/bpf/cpustat_user.c
@@ -0,0 +1,251 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <sched.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <locale.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+static int cstate_map_fd, pstate_map_fd;
+
+#define MAX_CPU			8
+#define MAX_PSTATE_ENTRIES	5
+#define MAX_CSTATE_ENTRIES	3
+#define MAX_STARS		40
+
+#define CPUFREQ_MAX_SYSFS_PATH	"/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq"
+#define CPUFREQ_LOWEST_FREQ	"208000"
+#define CPUFREQ_HIGHEST_FREQ	"12000000"
+
+struct cpu_stat_data {
+	unsigned long cstate[MAX_CSTATE_ENTRIES];
+	unsigned long pstate[MAX_PSTATE_ENTRIES];
+};
+
+static struct cpu_stat_data stat_data[MAX_CPU];
+
+static void cpu_stat_print(void)
+{
+	int i, j;
+	char state_str[sizeof("cstate-9")];
+	struct cpu_stat_data *data;
+
+	/* Clear screen */
+	printf("\033[2J");
+
+	/* Header */
+	printf("\nCPU states statistics:\n");
+	printf("%-10s ", "state(ms)");
+
+	for (i = 0; i < MAX_CSTATE_ENTRIES; i++) {
+		sprintf(state_str, "cstate-%d", i);
+		printf("%-11s ", state_str);
+	}
+
+	for (i = 0; i < MAX_PSTATE_ENTRIES; i++) {
+		sprintf(state_str, "pstate-%d", i);
+		printf("%-11s ", state_str);
+	}
+
+	printf("\n");
+
+	for (j = 0; j < MAX_CPU; j++) {
+		data = &stat_data[j];
+
+		printf("CPU-%-6d ", j);
+		for (i = 0; i < MAX_CSTATE_ENTRIES; i++)
+			printf("%-11lu ", data->cstate[i] / 1000000);
+
+		for (i = 0; i < MAX_PSTATE_ENTRIES; i++)
+			printf("%-11lu ", data->pstate[i] / 1000000);
+
+		printf("\n");
+	}
+}
+
+static void cpu_stat_update(int cstate_fd, int pstate_fd)
+{
+	unsigned long key, value;
+	int c, i;
+
+	for (c = 0; c < MAX_CPU; c++) {
+		for (i = 0; i < MAX_CSTATE_ENTRIES; i++) {
+			key = c * MAX_CSTATE_ENTRIES + i;
+			bpf_map_lookup_elem(cstate_fd, &key, &value);
+			stat_data[c].cstate[i] = value;
+		}
+
+		for (i = 0; i < MAX_PSTATE_ENTRIES; i++) {
+			key = c * MAX_PSTATE_ENTRIES + i;
+			bpf_map_lookup_elem(pstate_fd, &key, &value);
+			stat_data[c].pstate[i] = value;
+		}
+	}
+}
+
+/*
+ * This function is copied from 'idlestat' tool function
+ * idlestat_wake_all() in idlestate.c.
+ *
+ * It sets the self running task affinity to cpus one by one so can wake up
+ * the specific CPU to handle scheduling; this results in all cpus can be
+ * waken up once and produce ftrace event 'trace_cpu_idle'.
+ */
+static int cpu_stat_inject_cpu_idle_event(void)
+{
+	int rcpu, i, ret;
+	cpu_set_t cpumask;
+	cpu_set_t original_cpumask;
+
+	ret = sysconf(_SC_NPROCESSORS_CONF);
+	if (ret < 0)
+		return -1;
+
+	rcpu = sched_getcpu();
+	if (rcpu < 0)
+		return -1;
+
+	/* Keep track of the CPUs we will run on */
+	sched_getaffinity(0, sizeof(original_cpumask), &original_cpumask);
+
+	for (i = 0; i < ret; i++) {
+
+		/* Pointless to wake up ourself */
+		if (i == rcpu)
+			continue;
+
+		/* Pointless to wake CPUs we will not run on */
+		if (!CPU_ISSET(i, &original_cpumask))
+			continue;
+
+		CPU_ZERO(&cpumask);
+		CPU_SET(i, &cpumask);
+
+		sched_setaffinity(0, sizeof(cpumask), &cpumask);
+	}
+
+	/* Enable all the CPUs of the original mask */
+	sched_setaffinity(0, sizeof(original_cpumask), &original_cpumask);
+	return 0;
+}
+
+/*
+ * It's possible to have no any frequency change for long time and cannot
+ * get ftrace event 'trace_cpu_frequency' for long period, this introduces
+ * big deviation for pstate statistics.
+ *
+ * To solve this issue, below code forces to set 'scaling_max_freq' to 208MHz
+ * for triggering ftrace event 'trace_cpu_frequency' and then recovery back to
+ * the maximum frequency value 1.2GHz.
+ */
+static int cpu_stat_inject_cpu_frequency_event(void)
+{
+	int len, fd;
+
+	fd = open(CPUFREQ_MAX_SYSFS_PATH, O_WRONLY);
+	if (fd < 0) {
+		printf("failed to open scaling_max_freq, errno=%d\n", errno);
+		return fd;
+	}
+
+	len = write(fd, CPUFREQ_LOWEST_FREQ, strlen(CPUFREQ_LOWEST_FREQ));
+	if (len < 0) {
+		printf("failed to open scaling_max_freq, errno=%d\n", errno);
+		goto err;
+	}
+
+	len = write(fd, CPUFREQ_HIGHEST_FREQ, strlen(CPUFREQ_HIGHEST_FREQ));
+	if (len < 0) {
+		printf("failed to open scaling_max_freq, errno=%d\n", errno);
+		goto err;
+	}
+
+err:
+	close(fd);
+	return len;
+}
+
+static void int_exit(int sig)
+{
+	cpu_stat_inject_cpu_idle_event();
+	cpu_stat_inject_cpu_frequency_event();
+	cpu_stat_update(cstate_map_fd, pstate_map_fd);
+	cpu_stat_print();
+	exit(0);
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int ret;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		printf("finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	cstate_map_fd = bpf_object__find_map_fd_by_name(obj, "cstate_duration");
+	pstate_map_fd = bpf_object__find_map_fd_by_name(obj, "pstate_duration");
+	if (cstate_map_fd < 0 || pstate_map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	ret = cpu_stat_inject_cpu_idle_event();
+	if (ret < 0)
+		return 1;
+
+	ret = cpu_stat_inject_cpu_frequency_event();
+	if (ret < 0)
+		return 1;
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	while (1) {
+		cpu_stat_update(cstate_map_fd, pstate_map_fd);
+		cpu_stat_print();
+		sleep(5);
+	}
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/do_hbm_test.sh b/samples/bpf/do_hbm_test.sh
new file mode 100755
index 000000000..7f4f72278
--- /dev/null
+++ b/samples/bpf/do_hbm_test.sh
@@ -0,0 +1,438 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (c) 2019 Facebook
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of version 2 of the GNU General Public
+# License as published by the Free Software Foundation.
+
+Usage() {
+  echo "Script for testing HBM (Host Bandwidth Manager) framework."
+  echo "It creates a cgroup to use for testing and load a BPF program to limit"
+  echo "egress or ingress bandwidth. It then uses iperf3 or netperf to create"
+  echo "loads. The output is the goodput in Mbps (unless -D was used)."
+  echo ""
+  echo "USAGE: $name [out] [-b=<prog>|--bpf=<prog>] [-c=<cc>|--cc=<cc>]"
+  echo "             [-D] [-d=<delay>|--delay=<delay>] [--debug] [-E] [--edt]"
+  echo "             [-f=<#flows>|--flows=<#flows>] [-h] [-i=<id>|--id=<id >]"
+  echo "             [-l] [-N] [--no_cn] [-p=<port>|--port=<port>] [-P]"
+  echo "             [-q=<qdisc>] [-R] [-s=<server>|--server=<server]"
+  echo "             [-S|--stats] -t=<time>|--time=<time>] [-w] [cubic|dctcp]"
+  echo "  Where:"
+  echo "    out               egress (default)"
+  echo "    -b or --bpf       BPF program filename to load and attach."
+  echo "                      Default is hbm_out_kern.o for egress,"
+  echo "    -c or -cc         TCP congestion control (cubic or dctcp)"
+  echo "    --debug           print BPF trace buffer"
+  echo "    -d or --delay     add a delay in ms using netem"
+  echo "    -D                In addition to the goodput in Mbps, it also outputs"
+  echo "                      other detailed information. This information is"
+  echo "                      test dependent (i.e. iperf3 or netperf)."
+  echo "    -E                enable ECN (not required for dctcp)"
+  echo "    --edt             use fq's Earliest Departure Time (requires fq)"
+  echo "    -f or --flows     number of concurrent flows (default=1)"
+  echo "    -i or --id        cgroup id (an integer, default is 1)"
+  echo "    -N                use netperf instead of iperf3"
+  echo "    --no_cn           Do not return CN notifications"
+  echo "    -l                do not limit flows using loopback"
+  echo "    -h                Help"
+  echo "    -p or --port      iperf3 port (default is 5201)"
+  echo "    -P                use an iperf3 instance for each flow"
+  echo "    -q                use the specified qdisc"
+  echo "    -r or --rate      rate in Mbps (default 1s 1Gbps)"
+  echo "    -R                Use TCP_RR for netperf. 1st flow has req"
+  echo "                      size of 10KB, rest of 1MB. Reply in all"
+  echo "                      cases is 1 byte."
+  echo "                      More detailed output for each flow can be found"
+  echo "                      in the files netperf.<cg>.<flow>, where <cg> is the"
+  echo "                      cgroup id as specified with the -i flag, and <flow>"
+  echo "                      is the flow id starting at 1 and increasing by 1 for"
+  echo "                      flow (as specified by -f)."
+  echo "    -s or --server    hostname of netperf server. Used to create netperf"
+  echo "                      test traffic between to hosts (default is within host)"
+  echo "                      netserver must be running on the host."
+  echo "    -S or --stats     whether to update hbm stats (default is yes)."
+  echo "    -t or --time      duration of iperf3 in seconds (default=5)"
+  echo "    -w                Work conserving flag. cgroup can increase its"
+  echo "                      bandwidth beyond the rate limit specified"
+  echo "                      while there is available bandwidth. Current"
+  echo "                      implementation assumes there is only one NIC"
+  echo "                      (eth0), but can be extended to support multiple"
+  echo "                       NICs."
+  echo "    cubic or dctcp    specify which TCP CC to use"
+  echo " "
+  exit
+}
+
+#set -x
+
+debug_flag=0
+args="$@"
+name="$0"
+netem=0
+cc=x
+dir="-o"
+dir_name="out"
+dur=5
+flows=1
+id=1
+prog=""
+port=5201
+rate=1000
+multi_iperf=0
+flow_cnt=1
+use_netperf=0
+rr=0
+ecn=0
+details=0
+server=""
+qdisc=""
+flags=""
+do_stats=0
+
+BPFFS=/sys/fs/bpf
+function config_bpffs () {
+	if mount | grep $BPFFS > /dev/null; then
+		echo "bpffs already mounted"
+	else
+		echo "bpffs not mounted. Mounting..."
+		mount -t bpf none $BPFFS
+	fi
+}
+
+function start_hbm () {
+  rm -f hbm.out
+  echo "./hbm $dir -n $id -r $rate -t $dur $flags $dbg $prog" > hbm.out
+  echo " " >> hbm.out
+  ./hbm $dir -n $id -r $rate -t $dur $flags $dbg $prog >> hbm.out 2>&1  &
+  echo $!
+}
+
+processArgs () {
+  for i in $args ; do
+    case $i in
+    # Support for upcoming ingress rate limiting
+    #in)         # support for upcoming ingress rate limiting
+    #  dir="-i"
+    #  dir_name="in"
+    #  ;;
+    out)
+      dir="-o"
+      dir_name="out"
+      ;;
+    -b=*|--bpf=*)
+      prog="${i#*=}"
+      ;;
+    -c=*|--cc=*)
+      cc="${i#*=}"
+      ;;
+    --no_cn)
+      flags="$flags --no_cn"
+      ;;
+    --debug)
+      flags="$flags -d"
+      debug_flag=1
+      ;;
+    -d=*|--delay=*)
+      netem="${i#*=}"
+      ;;
+    -D)
+      details=1
+      ;;
+    -E)
+      ecn=1
+      ;;
+    --edt)
+      flags="$flags --edt"
+      qdisc="fq"
+     ;;
+    -f=*|--flows=*)
+      flows="${i#*=}"
+      ;;
+    -i=*|--id=*)
+      id="${i#*=}"
+      ;;
+    -l)
+      flags="$flags -l"
+      ;;
+    -N)
+      use_netperf=1
+      ;;
+    -p=*|--port=*)
+      port="${i#*=}"
+      ;;
+    -P)
+      multi_iperf=1
+      ;;
+    -q=*)
+      qdisc="${i#*=}"
+      ;;
+    -r=*|--rate=*)
+      rate="${i#*=}"
+      ;;
+    -R)
+      rr=1
+      ;;
+    -s=*|--server=*)
+      server="${i#*=}"
+      ;;
+    -S|--stats)
+      flags="$flags -s"
+      do_stats=1
+      ;;
+    -t=*|--time=*)
+      dur="${i#*=}"
+      ;;
+    -w)
+      flags="$flags -w"
+      ;;
+    cubic)
+      cc=cubic
+      ;;
+    dctcp)
+      cc=dctcp
+      ;;
+    *)
+      echo "Unknown arg:$i"
+      Usage
+      ;;
+    esac
+  done
+}
+
+processArgs
+config_bpffs
+
+if [ $debug_flag -eq 1 ] ; then
+  rm -f hbm_out.log
+fi
+
+hbm_pid=$(start_hbm)
+usleep 100000
+
+host=`hostname`
+cg_base_dir=/sys/fs/cgroup/unified
+cg_dir="$cg_base_dir/cgroup-test-work-dir/hbm$id"
+
+echo $$ >> $cg_dir/cgroup.procs
+
+ulimit -l unlimited
+
+rm -f ss.out
+rm -f hbm.[0-9]*.$dir_name
+if [ $ecn -ne 0 ] ; then
+  sysctl -w -q -n net.ipv4.tcp_ecn=1
+fi
+
+if [ $use_netperf -eq 0 ] ; then
+  cur_cc=`sysctl -n net.ipv4.tcp_congestion_control`
+  if [ "$cc" != "x" ] ; then
+    sysctl -w -q -n net.ipv4.tcp_congestion_control=$cc
+  fi
+fi
+
+if [ "$netem" -ne "0" ] ; then
+  if [ "$qdisc" != "" ] ; then
+    echo "WARNING: Ignoring -q options because -d option used"
+  fi
+  tc qdisc del dev lo root > /dev/null 2>&1
+  tc qdisc add dev lo root netem delay $netem\ms > /dev/null 2>&1
+elif [ "$qdisc" != "" ] ; then
+  tc qdisc del dev eth0 root > /dev/null 2>&1
+  tc qdisc add dev eth0 root $qdisc > /dev/null 2>&1
+fi
+
+n=0
+m=$[$dur * 5]
+hn="::1"
+if [ $use_netperf -ne 0 ] ; then
+  if [ "$server" != "" ] ; then
+    hn=$server
+  fi
+fi
+
+( ping6 -i 0.2 -c $m $hn > ping.out 2>&1 ) &
+
+if [ $use_netperf -ne 0 ] ; then
+  begNetserverPid=`ps ax | grep netserver | grep --invert-match "grep" | \
+                   awk '{ print $1 }'`
+  if [ "$begNetserverPid" == "" ] ; then
+    if [ "$server" == "" ] ; then
+      ( ./netserver > /dev/null 2>&1) &
+      usleep 100000
+    fi
+  fi
+  flow_cnt=1
+  if [ "$server" == "" ] ; then
+    np_server=$host
+  else
+    np_server=$server
+  fi
+  if [ "$cc" == "x" ] ; then
+    np_cc=""
+  else
+    np_cc="-K $cc,$cc"
+  fi
+  replySize=1
+  while [ $flow_cnt -le $flows ] ; do
+    if [ $rr -ne 0 ] ; then
+      reqSize=1M
+      if [ $flow_cnt -eq 1 ] ; then
+        reqSize=10K
+      fi
+      if [ "$dir" == "-i" ] ; then
+        replySize=$reqSize
+        reqSize=1
+      fi
+      ( ./netperf -H $np_server -l $dur -f m -j -t TCP_RR  -- -r $reqSize,$replySize $np_cc -k P50_lATENCY,P90_LATENCY,LOCAL_TRANSPORT_RETRANS,REMOTE_TRANSPORT_RETRANS,LOCAL_SEND_THROUGHPUT,LOCAL_RECV_THROUGHPUT,REQUEST_SIZE,RESPONSE_SIZE > netperf.$id.$flow_cnt ) &
+    else
+      if [ "$dir" == "-i" ] ; then
+        ( ./netperf -H $np_server -l $dur -f m -j -t TCP_RR -- -r 1,10M $np_cc -k P50_LATENCY,P90_LATENCY,LOCAL_TRANSPORT_RETRANS,LOCAL_SEND_THROUGHPUT,REMOTE_TRANSPORT_RETRANS,REMOTE_SEND_THROUGHPUT,REQUEST_SIZE,RESPONSE_SIZE > netperf.$id.$flow_cnt ) &
+      else
+        ( ./netperf -H $np_server -l $dur -f m -j -t TCP_STREAM -- $np_cc -k P50_lATENCY,P90_LATENCY,LOCAL_TRANSPORT_RETRANS,LOCAL_SEND_THROUGHPUT,REQUEST_SIZE,RESPONSE_SIZE > netperf.$id.$flow_cnt ) &
+      fi
+    fi
+    flow_cnt=$[flow_cnt+1]
+  done
+
+# sleep for duration of test (plus some buffer)
+  n=$[dur+2]
+  sleep $n
+
+# force graceful termination of netperf
+  pids=`pgrep netperf`
+  for p in $pids ; do
+    kill -SIGALRM $p
+  done
+
+  flow_cnt=1
+  rate=0
+  if [ $details -ne 0 ] ; then
+    echo ""
+    echo "Details for HBM in cgroup $id"
+    if [ $do_stats -eq 1 ] ; then
+      if [ -e hbm.$id.$dir_name ] ; then
+        cat hbm.$id.$dir_name
+      fi
+    fi
+  fi
+  while [ $flow_cnt -le $flows ] ; do
+    if [ "$dir" == "-i" ] ; then
+      r=`cat netperf.$id.$flow_cnt | grep -o "REMOTE_SEND_THROUGHPUT=[0-9]*" | grep -o "[0-9]*"`
+    else
+      r=`cat netperf.$id.$flow_cnt | grep -o "LOCAL_SEND_THROUGHPUT=[0-9]*" | grep -o "[0-9]*"`
+    fi
+    echo "rate for flow $flow_cnt: $r"
+    rate=$[rate+r]
+    if [ $details -ne 0 ] ; then
+      echo "-----"
+      echo "Details for cgroup $id, flow $flow_cnt"
+      cat netperf.$id.$flow_cnt
+    fi
+    flow_cnt=$[flow_cnt+1]
+  done
+  if [ $details -ne 0 ] ; then
+    echo ""
+    delay=`grep "avg" ping.out | grep -o "= [0-9.]*/[0-9.]*" | grep -o "[0-9.]*$"`
+    echo "PING AVG DELAY:$delay"
+    echo "AGGREGATE_GOODPUT:$rate"
+  else
+    echo $rate
+  fi
+elif [ $multi_iperf -eq 0 ] ; then
+  (iperf3 -s -p $port -1 > /dev/null 2>&1) &
+  usleep 100000
+  iperf3 -c $host -p $port -i 0 -P $flows -f m -t $dur > iperf.$id
+  rates=`grep receiver iperf.$id | grep -o "[0-9.]* Mbits" | grep -o "^[0-9]*"`
+  rate=`echo $rates | grep -o "[0-9]*$"`
+
+  if [ $details -ne 0 ] ; then
+    echo ""
+    echo "Details for HBM in cgroup $id"
+    if [ $do_stats -eq 1 ] ; then
+      if [ -e hbm.$id.$dir_name ] ; then
+        cat hbm.$id.$dir_name
+      fi
+    fi
+    delay=`grep "avg" ping.out | grep -o "= [0-9.]*/[0-9.]*" | grep -o "[0-9.]*$"`
+    echo "PING AVG DELAY:$delay"
+    echo "AGGREGATE_GOODPUT:$rate"
+  else
+    echo $rate
+  fi
+else
+  flow_cnt=1
+  while [ $flow_cnt -le $flows ] ; do
+    (iperf3 -s -p $port -1 > /dev/null 2>&1) &
+    ( iperf3 -c $host -p $port -i 0 -P 1 -f m -t $dur | grep receiver | grep -o "[0-9.]* Mbits" | grep -o "^[0-9]*" | grep -o "[0-9]*$" > iperf3.$id.$flow_cnt ) &
+    port=$[port+1]
+    flow_cnt=$[flow_cnt+1]
+  done
+  n=$[dur+1]
+  sleep $n
+  flow_cnt=1
+  rate=0
+  if [ $details -ne 0 ] ; then
+    echo ""
+    echo "Details for HBM in cgroup $id"
+    if [ $do_stats -eq 1 ] ; then
+      if [ -e hbm.$id.$dir_name ] ; then
+        cat hbm.$id.$dir_name
+      fi
+    fi
+  fi
+
+  while [ $flow_cnt -le $flows ] ; do
+    r=`cat iperf3.$id.$flow_cnt`
+#    echo "rate for flow $flow_cnt: $r"
+  if [ $details -ne 0 ] ; then
+    echo "Rate for cgroup $id, flow $flow_cnt LOCAL_SEND_THROUGHPUT=$r"
+  fi
+    rate=$[rate+r]
+    flow_cnt=$[flow_cnt+1]
+  done
+  if [ $details -ne 0 ] ; then
+    delay=`grep "avg" ping.out | grep -o "= [0-9.]*/[0-9.]*" | grep -o "[0-9.]*$"`
+    echo "PING AVG DELAY:$delay"
+    echo "AGGREGATE_GOODPUT:$rate"
+  else
+    echo $rate
+  fi
+fi
+
+if [ $use_netperf -eq 0 ] ; then
+  sysctl -w -q -n net.ipv4.tcp_congestion_control=$cur_cc
+fi
+if [ $ecn -ne 0 ] ; then
+  sysctl -w -q -n net.ipv4.tcp_ecn=0
+fi
+if [ "$netem" -ne "0" ] ; then
+  tc qdisc del dev lo root > /dev/null 2>&1
+fi
+if [ "$qdisc" != "" ] ; then
+  tc qdisc del dev eth0 root > /dev/null 2>&1
+fi
+sleep 2
+
+hbmPid=`ps ax | grep "hbm " | grep --invert-match "grep" | awk '{ print $1 }'`
+if [ "$hbmPid" == "$hbm_pid" ] ; then
+  kill $hbm_pid
+fi
+
+sleep 1
+
+# Detach any pinned BPF programs that may have lingered
+rm -rf $BPFFS/hbm*
+
+if [ $use_netperf -ne 0 ] ; then
+  if [ "$server" == "" ] ; then
+    if [ "$begNetserverPid" == "" ] ; then
+      netserverPid=`ps ax | grep netserver | grep --invert-match "grep" | awk '{ print $1 }'`
+      if [ "$netserverPid" != "" ] ; then
+        kill $netserverPid
+      fi
+    fi
+  fi
+fi
+exit
diff --git a/samples/bpf/fds_example.c b/samples/bpf/fds_example.c
new file mode 100644
index 000000000..88a26f3ce
--- /dev/null
+++ b/samples/bpf/fds_example.c
@@ -0,0 +1,195 @@
+#include <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <bpf/bpf.h>
+
+#include <bpf/libbpf.h>
+#include "bpf_insn.h"
+#include "sock_example.h"
+#include "bpf_util.h"
+
+#define BPF_F_PIN	(1 << 0)
+#define BPF_F_GET	(1 << 1)
+#define BPF_F_PIN_GET	(BPF_F_PIN | BPF_F_GET)
+
+#define BPF_F_KEY	(1 << 2)
+#define BPF_F_VAL	(1 << 3)
+#define BPF_F_KEY_VAL	(BPF_F_KEY | BPF_F_VAL)
+
+#define BPF_M_UNSPEC	0
+#define BPF_M_MAP	1
+#define BPF_M_PROG	2
+
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+
+static void usage(void)
+{
+	printf("Usage: fds_example [...]\n");
+	printf("       -F <file>   File to pin/get object\n");
+	printf("       -P          |- pin object\n");
+	printf("       -G          `- get object\n");
+	printf("       -m          eBPF map mode\n");
+	printf("       -k <key>    |- map key\n");
+	printf("       -v <value>  `- map value\n");
+	printf("       -p          eBPF prog mode\n");
+	printf("       -o <object> `- object file\n");
+	printf("       -h          Display this help.\n");
+}
+
+static int bpf_prog_create(const char *object)
+{
+	static struct bpf_insn insns[] = {
+		BPF_MOV64_IMM(BPF_REG_0, 1),
+		BPF_EXIT_INSN(),
+	};
+	size_t insns_cnt = ARRAY_SIZE(insns);
+	struct bpf_object *obj;
+	int err;
+
+	if (object) {
+		obj = bpf_object__open_file(object, NULL);
+		assert(!libbpf_get_error(obj));
+		err = bpf_object__load(obj);
+		assert(!err);
+		return bpf_program__fd(bpf_object__next_program(obj, NULL));
+	} else {
+		LIBBPF_OPTS(bpf_prog_load_opts, opts,
+			.log_buf = bpf_log_buf,
+			.log_size = BPF_LOG_BUF_SIZE,
+		);
+
+		return bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL",
+				     insns, insns_cnt, &opts);
+	}
+}
+
+static int bpf_do_map(const char *file, uint32_t flags, uint32_t key,
+		      uint32_t value)
+{
+	int fd, ret;
+
+	if (flags & BPF_F_PIN) {
+		fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(uint32_t),
+				    sizeof(uint32_t), 1024, NULL);
+		printf("bpf: map fd:%d (%s)\n", fd, strerror(errno));
+		assert(fd > 0);
+
+		ret = bpf_obj_pin(fd, file);
+		printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
+		assert(ret == 0);
+	} else {
+		fd = bpf_obj_get(file);
+		printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
+		assert(fd > 0);
+	}
+
+	if ((flags & BPF_F_KEY_VAL) == BPF_F_KEY_VAL) {
+		ret = bpf_map_update_elem(fd, &key, &value, 0);
+		printf("bpf: fd:%d u->(%u:%u) ret:(%d,%s)\n", fd, key, value,
+		       ret, strerror(errno));
+		assert(ret == 0);
+	} else if (flags & BPF_F_KEY) {
+		ret = bpf_map_lookup_elem(fd, &key, &value);
+		printf("bpf: fd:%d l->(%u):%u ret:(%d,%s)\n", fd, key, value,
+		       ret, strerror(errno));
+		assert(ret == 0);
+	}
+
+	return 0;
+}
+
+static int bpf_do_prog(const char *file, uint32_t flags, const char *object)
+{
+	int fd, sock, ret;
+
+	if (flags & BPF_F_PIN) {
+		fd = bpf_prog_create(object);
+		printf("bpf: prog fd:%d (%s)\n", fd, strerror(errno));
+		assert(fd > 0);
+
+		ret = bpf_obj_pin(fd, file);
+		printf("bpf: pin ret:(%d,%s)\n", ret, strerror(errno));
+		assert(ret == 0);
+	} else {
+		fd = bpf_obj_get(file);
+		printf("bpf: get fd:%d (%s)\n", fd, strerror(errno));
+		assert(fd > 0);
+	}
+
+	sock = open_raw_sock("lo");
+	assert(sock > 0);
+
+	ret = setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &fd, sizeof(fd));
+	printf("bpf: sock:%d <- fd:%d attached ret:(%d,%s)\n", sock, fd,
+	       ret, strerror(errno));
+	assert(ret == 0);
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	const char *file = NULL, *object = NULL;
+	uint32_t key = 0, value = 0, flags = 0;
+	int opt, mode = BPF_M_UNSPEC;
+
+	while ((opt = getopt(argc, argv, "F:PGmk:v:po:")) != -1) {
+		switch (opt) {
+		/* General args */
+		case 'F':
+			file = optarg;
+			break;
+		case 'P':
+			flags |= BPF_F_PIN;
+			break;
+		case 'G':
+			flags |= BPF_F_GET;
+			break;
+		/* Map-related args */
+		case 'm':
+			mode = BPF_M_MAP;
+			break;
+		case 'k':
+			key = strtoul(optarg, NULL, 0);
+			flags |= BPF_F_KEY;
+			break;
+		case 'v':
+			value = strtoul(optarg, NULL, 0);
+			flags |= BPF_F_VAL;
+			break;
+		/* Prog-related args */
+		case 'p':
+			mode = BPF_M_PROG;
+			break;
+		case 'o':
+			object = optarg;
+			break;
+		default:
+			goto out;
+		}
+	}
+
+	if (!(flags & BPF_F_PIN_GET) || !file)
+		goto out;
+
+	switch (mode) {
+	case BPF_M_MAP:
+		return bpf_do_map(file, flags, key, value);
+	case BPF_M_PROG:
+		return bpf_do_prog(file, flags, object);
+	}
+out:
+	usage();
+	return -1;
+}
diff --git a/samples/bpf/gnu/stubs.h b/samples/bpf/gnu/stubs.h
new file mode 100644
index 000000000..1c638d9dc
--- /dev/null
+++ b/samples/bpf/gnu/stubs.h
@@ -0,0 +1 @@
+/* dummy .h to trick /usr/include/features.h to work with 'clang --target=bpf' */
diff --git a/samples/bpf/hash_func01.h b/samples/bpf/hash_func01.h
new file mode 100644
index 000000000..38255812e
--- /dev/null
+++ b/samples/bpf/hash_func01.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: LGPL-2.1
+ *
+ * Based on Paul Hsieh's (LGPG 2.1) hash function
+ * From: http://www.azillionmonkeys.com/qed/hash.html
+ */
+
+#define get16bits(d) (*((const __u16 *) (d)))
+
+static __always_inline
+__u32 SuperFastHash (const char *data, int len, __u32 initval) {
+	__u32 hash = initval;
+	__u32 tmp;
+	int rem;
+
+	if (len <= 0 || data == NULL) return 0;
+
+	rem = len & 3;
+	len >>= 2;
+
+	/* Main loop */
+#pragma clang loop unroll(full)
+	for (;len > 0; len--) {
+		hash  += get16bits (data);
+		tmp    = (get16bits (data+2) << 11) ^ hash;
+		hash   = (hash << 16) ^ tmp;
+		data  += 2*sizeof (__u16);
+		hash  += hash >> 11;
+	}
+
+	/* Handle end cases */
+	switch (rem) {
+        case 3: hash += get16bits (data);
+                hash ^= hash << 16;
+                hash ^= ((signed char)data[sizeof (__u16)]) << 18;
+                hash += hash >> 11;
+                break;
+        case 2: hash += get16bits (data);
+                hash ^= hash << 11;
+                hash += hash >> 17;
+                break;
+        case 1: hash += (signed char)*data;
+                hash ^= hash << 10;
+                hash += hash >> 1;
+	}
+
+	/* Force "avalanching" of final 127 bits */
+	hash ^= hash << 3;
+	hash += hash >> 5;
+	hash ^= hash << 4;
+	hash += hash >> 17;
+	hash ^= hash << 25;
+	hash += hash >> 6;
+
+	return hash;
+}
diff --git a/samples/bpf/hbm.c b/samples/bpf/hbm.c
new file mode 100644
index 000000000..fc88d4dbd
--- /dev/null
+++ b/samples/bpf/hbm.c
@@ -0,0 +1,515 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Example program for Host Bandwidth Management
+ *
+ * This program loads a cgroup skb BPF program to enforce cgroup output
+ * (egress) or input (ingress) bandwidth limits.
+ *
+ * USAGE: hbm [-d] [-l] [-n <id>] [-r <rate>] [-s] [-t <secs>] [-w] [-h] [prog]
+ *   Where:
+ *    -d	Print BPF trace debug buffer
+ *    -l	Also limit flows doing loopback
+ *    -n <#>	To create cgroup \"/hbm#\" and attach prog
+ *		Default is /hbm1
+ *    --no_cn   Do not return cn notifications
+ *    -r <rate>	Rate limit in Mbps
+ *    -s	Get HBM stats (marked, dropped, etc.)
+ *    -t <time>	Exit after specified seconds (default is 0)
+ *    -w	Work conserving flag. cgroup can increase its bandwidth
+ *		beyond the rate limit specified while there is available
+ *		bandwidth. Current implementation assumes there is only
+ *		NIC (eth0), but can be extended to support multiple NICs.
+ *		Currently only supported for egress.
+ *    -h	Print this info
+ *    prog	BPF program file name. Name defaults to hbm_out_kern.o
+ */
+
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/unistd.h>
+#include <linux/compiler.h>
+
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <getopt.h>
+
+#include "cgroup_helpers.h"
+#include "hbm.h"
+#include "bpf_util.h"
+#include <bpf/libbpf.h>
+
+bool outFlag = true;
+int minRate = 1000;		/* cgroup rate limit in Mbps */
+int rate = 1000;		/* can grow if rate conserving is enabled */
+int dur = 1;
+bool stats_flag;
+bool loopback_flag;
+bool debugFlag;
+bool work_conserving_flag;
+bool no_cn_flag;
+bool edt_flag;
+
+static void Usage(void);
+static void read_trace_pipe2(void);
+static void do_error(char *msg, bool errno_flag);
+
+#define TRACEFS "/sys/kernel/tracing/"
+
+static struct bpf_program *bpf_prog;
+static struct bpf_object *obj;
+static int queue_stats_fd;
+
+static void read_trace_pipe2(void)
+{
+	int trace_fd;
+	FILE *outf;
+	char *outFname = "hbm_out.log";
+
+	trace_fd = open(TRACEFS "trace_pipe", O_RDONLY, 0);
+	if (trace_fd < 0) {
+		printf("Error opening trace_pipe\n");
+		return;
+	}
+
+//	Future support of ingress
+//	if (!outFlag)
+//		outFname = "hbm_in.log";
+	outf = fopen(outFname, "w");
+
+	if (outf == NULL)
+		printf("Error creating %s\n", outFname);
+
+	while (1) {
+		static char buf[4097];
+		ssize_t sz;
+
+		sz = read(trace_fd, buf, sizeof(buf) - 1);
+		if (sz > 0) {
+			buf[sz] = 0;
+			puts(buf);
+			if (outf != NULL) {
+				fprintf(outf, "%s\n", buf);
+				fflush(outf);
+			}
+		}
+	}
+}
+
+static void do_error(char *msg, bool errno_flag)
+{
+	if (errno_flag)
+		printf("ERROR: %s, errno: %d\n", msg, errno);
+	else
+		printf("ERROR: %s\n", msg);
+	exit(1);
+}
+
+static int prog_load(char *prog)
+{
+	struct bpf_program *pos;
+	const char *sec_name;
+
+	obj = bpf_object__open_file(prog, NULL);
+	if (libbpf_get_error(obj)) {
+		printf("ERROR: opening BPF object file failed\n");
+		return 1;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		printf("ERROR: loading BPF object file failed\n");
+		goto err;
+	}
+
+	bpf_object__for_each_program(pos, obj) {
+		sec_name = bpf_program__section_name(pos);
+		if (sec_name && !strcmp(sec_name, "cgroup_skb/egress")) {
+			bpf_prog = pos;
+			break;
+		}
+	}
+	if (!bpf_prog) {
+		printf("ERROR: finding a prog in obj file failed\n");
+		goto err;
+	}
+
+	queue_stats_fd = bpf_object__find_map_fd_by_name(obj, "queue_stats");
+	if (queue_stats_fd < 0) {
+		printf("ERROR: finding a map in obj file failed\n");
+		goto err;
+	}
+
+	return 0;
+
+err:
+	bpf_object__close(obj);
+	return 1;
+}
+
+static int run_bpf_prog(char *prog, int cg_id)
+{
+	struct hbm_queue_stats qstats = {0};
+	char cg_dir[100], cg_pin_path[100];
+	struct bpf_link *link = NULL;
+	int key = 0;
+	int cg1 = 0;
+	int rc = 0;
+
+	sprintf(cg_dir, "/hbm%d", cg_id);
+	rc = prog_load(prog);
+	if (rc != 0)
+		return rc;
+
+	if (setup_cgroup_environment()) {
+		printf("ERROR: setting cgroup environment\n");
+		goto err;
+	}
+	cg1 = create_and_get_cgroup(cg_dir);
+	if (!cg1) {
+		printf("ERROR: create_and_get_cgroup\n");
+		goto err;
+	}
+	if (join_cgroup(cg_dir)) {
+		printf("ERROR: join_cgroup\n");
+		goto err;
+	}
+
+	qstats.rate = rate;
+	qstats.stats = stats_flag ? 1 : 0;
+	qstats.loopback = loopback_flag ? 1 : 0;
+	qstats.no_cn = no_cn_flag ? 1 : 0;
+	if (bpf_map_update_elem(queue_stats_fd, &key, &qstats, BPF_ANY)) {
+		printf("ERROR: Could not update map element\n");
+		goto err;
+	}
+
+	if (!outFlag)
+		bpf_program__set_expected_attach_type(bpf_prog, BPF_CGROUP_INET_INGRESS);
+
+	link = bpf_program__attach_cgroup(bpf_prog, cg1);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach_cgroup failed\n");
+		goto err;
+	}
+
+	sprintf(cg_pin_path, "/sys/fs/bpf/hbm%d", cg_id);
+	rc = bpf_link__pin(link, cg_pin_path);
+	if (rc < 0) {
+		printf("ERROR: bpf_link__pin failed: %d\n", rc);
+		goto err;
+	}
+
+	if (work_conserving_flag) {
+		struct timeval t0, t_last, t_new;
+		FILE *fin;
+		unsigned long long last_eth_tx_bytes, new_eth_tx_bytes;
+		signed long long last_cg_tx_bytes, new_cg_tx_bytes;
+		signed long long delta_time, delta_bytes, delta_rate;
+		int delta_ms;
+#define DELTA_RATE_CHECK 10000		/* in us */
+#define RATE_THRESHOLD 9500000000	/* 9.5 Gbps */
+
+		bpf_map_lookup_elem(queue_stats_fd, &key, &qstats);
+		if (gettimeofday(&t0, NULL) < 0)
+			do_error("gettimeofday failed", true);
+		t_last = t0;
+		fin = fopen("/sys/class/net/eth0/statistics/tx_bytes", "r");
+		if (fscanf(fin, "%llu", &last_eth_tx_bytes) != 1)
+			do_error("fscanf fails", false);
+		fclose(fin);
+		last_cg_tx_bytes = qstats.bytes_total;
+		while (true) {
+			usleep(DELTA_RATE_CHECK);
+			if (gettimeofday(&t_new, NULL) < 0)
+				do_error("gettimeofday failed", true);
+			delta_ms = (t_new.tv_sec - t0.tv_sec) * 1000 +
+				(t_new.tv_usec - t0.tv_usec)/1000;
+			if (delta_ms > dur * 1000)
+				break;
+			delta_time = (t_new.tv_sec - t_last.tv_sec) * 1000000 +
+				(t_new.tv_usec - t_last.tv_usec);
+			if (delta_time == 0)
+				continue;
+			t_last = t_new;
+			fin = fopen("/sys/class/net/eth0/statistics/tx_bytes",
+				    "r");
+			if (fscanf(fin, "%llu", &new_eth_tx_bytes) != 1)
+				do_error("fscanf fails", false);
+			fclose(fin);
+			printf("  new_eth_tx_bytes:%llu\n",
+			       new_eth_tx_bytes);
+			bpf_map_lookup_elem(queue_stats_fd, &key, &qstats);
+			new_cg_tx_bytes = qstats.bytes_total;
+			delta_bytes = new_eth_tx_bytes - last_eth_tx_bytes;
+			last_eth_tx_bytes = new_eth_tx_bytes;
+			delta_rate = (delta_bytes * 8000000) / delta_time;
+			printf("%5d - eth_rate:%.1fGbps cg_rate:%.3fGbps",
+			       delta_ms, delta_rate/1000000000.0,
+			       rate/1000.0);
+			if (delta_rate < RATE_THRESHOLD) {
+				/* can increase cgroup rate limit, but first
+				 * check if we are using the current limit.
+				 * Currently increasing by 6.25%, unknown
+				 * if that is the optimal rate.
+				 */
+				int rate_diff100;
+
+				delta_bytes = new_cg_tx_bytes -
+					last_cg_tx_bytes;
+				last_cg_tx_bytes = new_cg_tx_bytes;
+				delta_rate = (delta_bytes * 8000000) /
+					delta_time;
+				printf(" rate:%.3fGbps",
+				       delta_rate/1000000000.0);
+				rate_diff100 = (((long long)rate)*1000000 -
+						     delta_rate) * 100 /
+					(((long long) rate) * 1000000);
+				printf("  rdiff:%d", rate_diff100);
+				if (rate_diff100  <= 3) {
+					rate += (rate >> 4);
+					if (rate > RATE_THRESHOLD / 1000000)
+						rate = RATE_THRESHOLD / 1000000;
+					qstats.rate = rate;
+					printf(" INC\n");
+				} else {
+					printf("\n");
+				}
+			} else {
+				/* Need to decrease cgroup rate limit.
+				 * Currently decreasing by 12.5%, unknown
+				 * if that is optimal
+				 */
+				printf(" DEC\n");
+				rate -= (rate >> 3);
+				if (rate < minRate)
+					rate = minRate;
+				qstats.rate = rate;
+			}
+			if (bpf_map_update_elem(queue_stats_fd, &key, &qstats, BPF_ANY))
+				do_error("update map element fails", false);
+		}
+	} else {
+		sleep(dur);
+	}
+	// Get stats!
+	if (stats_flag && bpf_map_lookup_elem(queue_stats_fd, &key, &qstats)) {
+		char fname[100];
+		FILE *fout;
+
+		if (!outFlag)
+			sprintf(fname, "hbm.%d.in", cg_id);
+		else
+			sprintf(fname, "hbm.%d.out", cg_id);
+		fout = fopen(fname, "w");
+		fprintf(fout, "id:%d\n", cg_id);
+		fprintf(fout, "ERROR: Could not lookup queue_stats\n");
+		fclose(fout);
+	} else if (stats_flag && qstats.lastPacketTime >
+		   qstats.firstPacketTime) {
+		long long delta_us = (qstats.lastPacketTime -
+				      qstats.firstPacketTime)/1000;
+		unsigned int rate_mbps = ((qstats.bytes_total -
+					   qstats.bytes_dropped) * 8 /
+					  delta_us);
+		double percent_pkts, percent_bytes;
+		char fname[100];
+		FILE *fout;
+		int k;
+		static const char *returnValNames[] = {
+			"DROP_PKT",
+			"ALLOW_PKT",
+			"DROP_PKT_CWR",
+			"ALLOW_PKT_CWR"
+		};
+#define RET_VAL_COUNT 4
+
+// Future support of ingress
+//		if (!outFlag)
+//			sprintf(fname, "hbm.%d.in", cg_id);
+//		else
+		sprintf(fname, "hbm.%d.out", cg_id);
+		fout = fopen(fname, "w");
+		fprintf(fout, "id:%d\n", cg_id);
+		fprintf(fout, "rate_mbps:%d\n", rate_mbps);
+		fprintf(fout, "duration:%.1f secs\n",
+			(qstats.lastPacketTime - qstats.firstPacketTime) /
+			1000000000.0);
+		fprintf(fout, "packets:%d\n", (int)qstats.pkts_total);
+		fprintf(fout, "bytes_MB:%d\n", (int)(qstats.bytes_total /
+						     1000000));
+		fprintf(fout, "pkts_dropped:%d\n", (int)qstats.pkts_dropped);
+		fprintf(fout, "bytes_dropped_MB:%d\n",
+			(int)(qstats.bytes_dropped /
+						       1000000));
+		// Marked Pkts and Bytes
+		percent_pkts = (qstats.pkts_marked * 100.0) /
+			(qstats.pkts_total + 1);
+		percent_bytes = (qstats.bytes_marked * 100.0) /
+			(qstats.bytes_total + 1);
+		fprintf(fout, "pkts_marked_percent:%6.2f\n", percent_pkts);
+		fprintf(fout, "bytes_marked_percent:%6.2f\n", percent_bytes);
+
+		// Dropped Pkts and Bytes
+		percent_pkts = (qstats.pkts_dropped * 100.0) /
+			(qstats.pkts_total + 1);
+		percent_bytes = (qstats.bytes_dropped * 100.0) /
+			(qstats.bytes_total + 1);
+		fprintf(fout, "pkts_dropped_percent:%6.2f\n", percent_pkts);
+		fprintf(fout, "bytes_dropped_percent:%6.2f\n", percent_bytes);
+
+		// ECN CE markings
+		percent_pkts = (qstats.pkts_ecn_ce * 100.0) /
+			(qstats.pkts_total + 1);
+		fprintf(fout, "pkts_ecn_ce:%6.2f (%d)\n", percent_pkts,
+			(int)qstats.pkts_ecn_ce);
+
+		// Average cwnd
+		fprintf(fout, "avg cwnd:%d\n",
+			(int)(qstats.sum_cwnd / (qstats.sum_cwnd_cnt + 1)));
+		// Average rtt
+		fprintf(fout, "avg rtt:%d\n",
+			(int)(qstats.sum_rtt / (qstats.pkts_total + 1)));
+		// Average credit
+		if (edt_flag)
+			fprintf(fout, "avg credit_ms:%.03f\n",
+				(qstats.sum_credit /
+				 (qstats.pkts_total + 1.0)) / 1000000.0);
+		else
+			fprintf(fout, "avg credit:%d\n",
+				(int)(qstats.sum_credit /
+				      (1500 * ((int)qstats.pkts_total ) + 1)));
+
+		// Return values stats
+		for (k = 0; k < RET_VAL_COUNT; k++) {
+			percent_pkts = (qstats.returnValCount[k] * 100.0) /
+				(qstats.pkts_total + 1);
+			fprintf(fout, "%s:%6.2f (%d)\n", returnValNames[k],
+				percent_pkts, (int)qstats.returnValCount[k]);
+		}
+		fclose(fout);
+	}
+
+	if (debugFlag)
+		read_trace_pipe2();
+	goto cleanup;
+
+err:
+	rc = 1;
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+
+	if (cg1 != -1)
+		close(cg1);
+
+	if (rc != 0)
+		cleanup_cgroup_environment();
+	return rc;
+}
+
+static void Usage(void)
+{
+	printf("This program loads a cgroup skb BPF program to enforce\n"
+	       "cgroup output (egress) bandwidth limits.\n\n"
+	       "USAGE: hbm [-o] [-d]  [-l] [-n <id>] [--no_cn] [-r <rate>]\n"
+	       "           [-s] [-t <secs>] [-w] [-h] [prog]\n"
+	       "  Where:\n"
+	       "    -o         indicates egress direction (default)\n"
+	       "    -d         print BPF trace debug buffer\n"
+	       "    --edt      use fq's Earliest Departure Time\n"
+	       "    -l         also limit flows using loopback\n"
+	       "    -n <#>     to create cgroup \"/hbm#\" and attach prog\n"
+	       "               Default is /hbm1\n"
+	       "    --no_cn    disable CN notifications\n"
+	       "    -r <rate>  Rate in Mbps\n"
+	       "    -s         Update HBM stats\n"
+	       "    -t <time>  Exit after specified seconds (default is 0)\n"
+	       "    -w	       Work conserving flag. cgroup can increase\n"
+	       "               bandwidth beyond the rate limit specified\n"
+	       "               while there is available bandwidth. Current\n"
+	       "               implementation assumes there is only eth0\n"
+	       "               but can be extended to support multiple NICs\n"
+	       "    -h         print this info\n"
+	       "    prog       BPF program file name. Name defaults to\n"
+	       "                 hbm_out_kern.o\n");
+}
+
+int main(int argc, char **argv)
+{
+	char *prog = "hbm_out_kern.o";
+	int  k;
+	int cg_id = 1;
+	char *optstring = "iodln:r:st:wh";
+	struct option loptions[] = {
+		{"no_cn", 0, NULL, 1},
+		{"edt", 0, NULL, 2},
+		{NULL, 0, NULL, 0}
+	};
+
+	while ((k = getopt_long(argc, argv, optstring, loptions, NULL)) != -1) {
+		switch (k) {
+		case 1:
+			no_cn_flag = true;
+			break;
+		case 2:
+			prog = "hbm_edt_kern.o";
+			edt_flag = true;
+			break;
+		case'o':
+			break;
+		case 'd':
+			debugFlag = true;
+			break;
+		case 'l':
+			loopback_flag = true;
+			break;
+		case 'n':
+			cg_id = atoi(optarg);
+			break;
+		case 'r':
+			minRate = atoi(optarg) * 1.024;
+			rate = minRate;
+			break;
+		case 's':
+			stats_flag = true;
+			break;
+		case 't':
+			dur = atoi(optarg);
+			break;
+		case 'w':
+			work_conserving_flag = true;
+			break;
+		case '?':
+			if (optopt == 'n' || optopt == 'r' || optopt == 't')
+				fprintf(stderr,
+					"Option -%c requires an argument.\n\n",
+					optopt);
+		case 'h':
+		default:
+			Usage();
+			return 0;
+		}
+	}
+
+	if (optind < argc)
+		prog = argv[optind];
+	printf("HBM prog: %s\n", prog != NULL ? prog : "NULL");
+
+	/* Use libbpf 1.0 API mode */
+	libbpf_set_strict_mode(LIBBPF_STRICT_ALL);
+
+	return run_bpf_prog(prog, cg_id);
+}
diff --git a/samples/bpf/hbm.h b/samples/bpf/hbm.h
new file mode 100644
index 000000000..f0963ed6a
--- /dev/null
+++ b/samples/bpf/hbm.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Include file for Host Bandwidth Management (HBM) programs
+ */
+struct hbm_vqueue {
+	struct bpf_spin_lock lock;
+	/* 4 byte hole */
+	unsigned long long lasttime;	/* In ns */
+	int credit;			/* In bytes */
+	unsigned int rate;		/* In bytes per NS << 20 */
+};
+
+struct hbm_queue_stats {
+	unsigned long rate;		/* in Mbps*/
+	unsigned long stats:1,		/* get HBM stats (marked, dropped,..) */
+		loopback:1,		/* also limit flows using loopback */
+		no_cn:1;		/* do not use cn flags */
+	unsigned long long pkts_marked;
+	unsigned long long bytes_marked;
+	unsigned long long pkts_dropped;
+	unsigned long long bytes_dropped;
+	unsigned long long pkts_total;
+	unsigned long long bytes_total;
+	unsigned long long firstPacketTime;
+	unsigned long long lastPacketTime;
+	unsigned long long pkts_ecn_ce;
+	unsigned long long returnValCount[4];
+	unsigned long long sum_cwnd;
+	unsigned long long sum_rtt;
+	unsigned long long sum_cwnd_cnt;
+	long long sum_credit;
+};
diff --git a/samples/bpf/hbm_edt_kern.c b/samples/bpf/hbm_edt_kern.c
new file mode 100644
index 000000000..6294f1d71
--- /dev/null
+++ b/samples/bpf/hbm_edt_kern.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Sample Host Bandwidth Manager (HBM) BPF program.
+ *
+ * A cgroup skb BPF egress program to limit cgroup output bandwidth.
+ * It uses a modified virtual token bucket queue to limit average
+ * egress bandwidth. The implementation uses credits instead of tokens.
+ * Negative credits imply that queueing would have happened (this is
+ * a virtual queue, so no queueing is done by it. However, queueing may
+ * occur at the actual qdisc (which is not used for rate limiting).
+ *
+ * This implementation uses 3 thresholds, one to start marking packets and
+ * the other two to drop packets:
+ *                                  CREDIT
+ *        - <--------------------------|------------------------> +
+ *              |    |          |      0
+ *              |  Large pkt    |
+ *              |  drop thresh  |
+ *   Small pkt drop             Mark threshold
+ *       thresh
+ *
+ * The effect of marking depends on the type of packet:
+ * a) If the packet is ECN enabled and it is a TCP packet, then the packet
+ *    is ECN marked.
+ * b) If the packet is a TCP packet, then we probabilistically call tcp_cwr
+ *    to reduce the congestion window. The current implementation uses a linear
+ *    distribution (0% probability at marking threshold, 100% probability
+ *    at drop threshold).
+ * c) If the packet is not a TCP packet, then it is dropped.
+ *
+ * If the credit is below the drop threshold, the packet is dropped. If it
+ * is a TCP packet, then it also calls tcp_cwr since packets dropped by
+ * a cgroup skb BPF program do not automatically trigger a call to
+ * tcp_cwr in the current kernel code.
+ *
+ * This BPF program actually uses 2 drop thresholds, one threshold
+ * for larger packets (>= 120 bytes) and another for smaller packets. This
+ * protects smaller packets such as SYNs, ACKs, etc.
+ *
+ * The default bandwidth limit is set at 1Gbps but this can be changed by
+ * a user program through a shared BPF map. In addition, by default this BPF
+ * program does not limit connections using loopback. This behavior can be
+ * overwritten by the user program. There is also an option to calculate
+ * some statistics, such as percent of packets marked or dropped, which
+ * a user program, such as hbm, can access.
+ */
+
+#include "hbm_kern.h"
+
+SEC("cgroup_skb/egress")
+int _hbm_out_cg(struct __sk_buff *skb)
+{
+	long long delta = 0, delta_send;
+	unsigned long long curtime, sendtime;
+	struct hbm_queue_stats *qsp = NULL;
+	unsigned int queue_index = 0;
+	bool congestion_flag = false;
+	bool ecn_ce_flag = false;
+	struct hbm_pkt_info pkti = {};
+	struct hbm_vqueue *qdp;
+	bool drop_flag = false;
+	bool cwr_flag = false;
+	int len = skb->len;
+	int rv = ALLOW_PKT;
+
+	qsp = bpf_map_lookup_elem(&queue_stats, &queue_index);
+
+	// Check if we should ignore loopback traffic
+	if (qsp != NULL && !qsp->loopback && (skb->ifindex == 1))
+		return ALLOW_PKT;
+
+	hbm_get_pkt_info(skb, &pkti);
+
+	// We may want to account for the length of headers in len
+	// calculation, like ETH header + overhead, specially if it
+	// is a gso packet. But I am not doing it right now.
+
+	qdp = bpf_get_local_storage(&queue_state, 0);
+	if (!qdp)
+		return ALLOW_PKT;
+	if (qdp->lasttime == 0)
+		hbm_init_edt_vqueue(qdp, 1024);
+
+	curtime = bpf_ktime_get_ns();
+
+	// Begin critical section
+	bpf_spin_lock(&qdp->lock);
+	delta = qdp->lasttime - curtime;
+	// bound bursts to 100us
+	if (delta < -BURST_SIZE_NS) {
+		// negative delta is a credit that allows bursts
+		qdp->lasttime = curtime - BURST_SIZE_NS;
+		delta = -BURST_SIZE_NS;
+	}
+	sendtime = qdp->lasttime;
+	delta_send = BYTES_TO_NS(len, qdp->rate);
+	__sync_add_and_fetch(&(qdp->lasttime), delta_send);
+	bpf_spin_unlock(&qdp->lock);
+	// End critical section
+
+	// Set EDT of packet
+	skb->tstamp = sendtime;
+
+	// Check if we should update rate
+	if (qsp != NULL && (qsp->rate * 128) != qdp->rate)
+		qdp->rate = qsp->rate * 128;
+
+	// Set flags (drop, congestion, cwr)
+	// last packet will be sent in the future, bound latency
+	if (delta > DROP_THRESH_NS || (delta > LARGE_PKT_DROP_THRESH_NS &&
+				       len > LARGE_PKT_THRESH)) {
+		drop_flag = true;
+		if (pkti.is_tcp && pkti.ecn == 0)
+			cwr_flag = true;
+	} else if (delta > MARK_THRESH_NS) {
+		if (pkti.is_tcp)
+			congestion_flag = true;
+		else
+			drop_flag = true;
+	}
+
+	if (congestion_flag) {
+		if (bpf_skb_ecn_set_ce(skb)) {
+			ecn_ce_flag = true;
+		} else {
+			if (pkti.is_tcp) {
+				unsigned int rand = bpf_get_prandom_u32();
+
+				if (delta >= MARK_THRESH_NS +
+				    (rand % MARK_REGION_SIZE_NS)) {
+					// Do congestion control
+					cwr_flag = true;
+				}
+			} else if (len > LARGE_PKT_THRESH) {
+				// Problem if too many small packets?
+				drop_flag = true;
+				congestion_flag = false;
+			}
+		}
+	}
+
+	if (pkti.is_tcp && drop_flag && pkti.packets_out <= 1) {
+		drop_flag = false;
+		cwr_flag = true;
+		congestion_flag = false;
+	}
+
+	if (qsp != NULL && qsp->no_cn)
+			cwr_flag = false;
+
+	hbm_update_stats(qsp, len, curtime, congestion_flag, drop_flag,
+			 cwr_flag, ecn_ce_flag, &pkti, (int) delta);
+
+	if (drop_flag) {
+		__sync_add_and_fetch(&(qdp->lasttime), -delta_send);
+		rv = DROP_PKT;
+	}
+
+	if (cwr_flag)
+		rv |= CWR;
+	return rv;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/hbm_kern.h b/samples/bpf/hbm_kern.h
new file mode 100644
index 000000000..1752a46a2
--- /dev/null
+++ b/samples/bpf/hbm_kern.h
@@ -0,0 +1,215 @@
+/* SPDX-License-Identifier: GPL-2.0
+ *
+ * Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Include file for sample Host Bandwidth Manager (HBM) BPF programs
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/filter.h>
+#include <uapi/linux/pkt_cls.h>
+#include <net/ipv6.h>
+#include <net/inet_ecn.h>
+#include <bpf/bpf_endian.h>
+#include <bpf/bpf_helpers.h>
+#include "hbm.h"
+
+#define DROP_PKT	0
+#define ALLOW_PKT	1
+#define TCP_ECN_OK	1
+#define CWR		2
+
+#ifndef HBM_DEBUG  // Define HBM_DEBUG to enable debugging
+#undef bpf_printk
+#define bpf_printk(fmt, ...)
+#endif
+
+#define INITIAL_CREDIT_PACKETS	100
+#define MAX_BYTES_PER_PACKET	1500
+#define MARK_THRESH		(40 * MAX_BYTES_PER_PACKET)
+#define DROP_THRESH		(80 * 5 * MAX_BYTES_PER_PACKET)
+#define LARGE_PKT_DROP_THRESH	(DROP_THRESH - (15 * MAX_BYTES_PER_PACKET))
+#define MARK_REGION_SIZE	(LARGE_PKT_DROP_THRESH - MARK_THRESH)
+#define LARGE_PKT_THRESH	120
+#define MAX_CREDIT		(100 * MAX_BYTES_PER_PACKET)
+#define INIT_CREDIT		(INITIAL_CREDIT_PACKETS * MAX_BYTES_PER_PACKET)
+
+// Time base accounting for fq's EDT
+#define BURST_SIZE_NS		100000 // 100us
+#define MARK_THRESH_NS		50000 // 50us
+#define DROP_THRESH_NS		500000 // 500us
+// Reserve 20us of queuing for small packets (less than 120 bytes)
+#define LARGE_PKT_DROP_THRESH_NS (DROP_THRESH_NS - 20000)
+#define MARK_REGION_SIZE_NS	(LARGE_PKT_DROP_THRESH_NS - MARK_THRESH_NS)
+
+// rate in bytes per ns << 20
+#define CREDIT_PER_NS(delta, rate) ((((u64)(delta)) * (rate)) >> 20)
+#define BYTES_PER_NS(delta, rate) ((((u64)(delta)) * (rate)) >> 20)
+#define BYTES_TO_NS(bytes, rate) div64_u64(((u64)(bytes)) << 20, (u64)(rate))
+
+struct {
+	__uint(type, BPF_MAP_TYPE_CGROUP_STORAGE);
+	__type(key, struct bpf_cgroup_storage_key);
+	__type(value, struct hbm_vqueue);
+} queue_state SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(max_entries, 1);
+	__type(key, u32);
+	__type(value, struct hbm_queue_stats);
+} queue_stats SEC(".maps");
+
+struct hbm_pkt_info {
+	int	cwnd;
+	int	rtt;
+	int	packets_out;
+	bool	is_ip;
+	bool	is_tcp;
+	short	ecn;
+};
+
+static int get_tcp_info(struct __sk_buff *skb, struct hbm_pkt_info *pkti)
+{
+	struct bpf_sock *sk;
+	struct bpf_tcp_sock *tp;
+
+	sk = skb->sk;
+	if (sk) {
+		sk = bpf_sk_fullsock(sk);
+		if (sk) {
+			if (sk->protocol == IPPROTO_TCP) {
+				tp = bpf_tcp_sock(sk);
+				if (tp) {
+					pkti->cwnd = tp->snd_cwnd;
+					pkti->rtt = tp->srtt_us >> 3;
+					pkti->packets_out = tp->packets_out;
+					return 0;
+				}
+			}
+		}
+	}
+	pkti->cwnd = 0;
+	pkti->rtt = 0;
+	pkti->packets_out = 0;
+	return 1;
+}
+
+static void hbm_get_pkt_info(struct __sk_buff *skb,
+			     struct hbm_pkt_info *pkti)
+{
+	struct iphdr iph;
+	struct ipv6hdr *ip6h;
+
+	pkti->cwnd = 0;
+	pkti->rtt = 0;
+	bpf_skb_load_bytes(skb, 0, &iph, 12);
+	if (iph.version == 6) {
+		ip6h = (struct ipv6hdr *)&iph;
+		pkti->is_ip = true;
+		pkti->is_tcp = (ip6h->nexthdr == 6);
+		pkti->ecn = (ip6h->flow_lbl[0] >> 4) & INET_ECN_MASK;
+	} else if (iph.version == 4) {
+		pkti->is_ip = true;
+		pkti->is_tcp = (iph.protocol == 6);
+		pkti->ecn = iph.tos & INET_ECN_MASK;
+	} else {
+		pkti->is_ip = false;
+		pkti->is_tcp = false;
+		pkti->ecn = 0;
+	}
+	if (pkti->is_tcp)
+		get_tcp_info(skb, pkti);
+}
+
+static __always_inline void hbm_init_vqueue(struct hbm_vqueue *qdp, int rate)
+{
+	bpf_printk("Initializing queue_state, rate:%d\n", rate * 128);
+	qdp->lasttime = bpf_ktime_get_ns();
+	qdp->credit = INIT_CREDIT;
+	qdp->rate = rate * 128;
+}
+
+static __always_inline void hbm_init_edt_vqueue(struct hbm_vqueue *qdp,
+						int rate)
+{
+	unsigned long long curtime;
+
+	curtime = bpf_ktime_get_ns();
+	bpf_printk("Initializing queue_state, rate:%d\n", rate * 128);
+	qdp->lasttime = curtime - BURST_SIZE_NS;	// support initial burst
+	qdp->credit = 0;				// not used
+	qdp->rate = rate * 128;
+}
+
+static __always_inline void hbm_update_stats(struct hbm_queue_stats *qsp,
+					     int len,
+					     unsigned long long curtime,
+					     bool congestion_flag,
+					     bool drop_flag,
+					     bool cwr_flag,
+					     bool ecn_ce_flag,
+					     struct hbm_pkt_info *pkti,
+					     int credit)
+{
+	int rv = ALLOW_PKT;
+
+	if (qsp != NULL) {
+		// Following is needed for work conserving
+		__sync_add_and_fetch(&(qsp->bytes_total), len);
+		if (qsp->stats) {
+			// Optionally update statistics
+			if (qsp->firstPacketTime == 0)
+				qsp->firstPacketTime = curtime;
+			qsp->lastPacketTime = curtime;
+			__sync_add_and_fetch(&(qsp->pkts_total), 1);
+			if (congestion_flag) {
+				__sync_add_and_fetch(&(qsp->pkts_marked), 1);
+				__sync_add_and_fetch(&(qsp->bytes_marked), len);
+			}
+			if (drop_flag) {
+				__sync_add_and_fetch(&(qsp->pkts_dropped), 1);
+				__sync_add_and_fetch(&(qsp->bytes_dropped),
+						     len);
+			}
+			if (ecn_ce_flag)
+				__sync_add_and_fetch(&(qsp->pkts_ecn_ce), 1);
+			if (pkti->cwnd) {
+				__sync_add_and_fetch(&(qsp->sum_cwnd),
+						     pkti->cwnd);
+				__sync_add_and_fetch(&(qsp->sum_cwnd_cnt), 1);
+			}
+			if (pkti->rtt)
+				__sync_add_and_fetch(&(qsp->sum_rtt),
+						     pkti->rtt);
+			__sync_add_and_fetch(&(qsp->sum_credit), credit);
+
+			if (drop_flag)
+				rv = DROP_PKT;
+			if (cwr_flag)
+				rv |= 2;
+			if (rv == DROP_PKT)
+				__sync_add_and_fetch(&(qsp->returnValCount[0]),
+						     1);
+			else if (rv == ALLOW_PKT)
+				__sync_add_and_fetch(&(qsp->returnValCount[1]),
+						     1);
+			else if (rv == 2)
+				__sync_add_and_fetch(&(qsp->returnValCount[2]),
+						     1);
+			else if (rv == 3)
+				__sync_add_and_fetch(&(qsp->returnValCount[3]),
+						     1);
+		}
+	}
+}
diff --git a/samples/bpf/hbm_out_kern.c b/samples/bpf/hbm_out_kern.c
new file mode 100644
index 000000000..829934bd4
--- /dev/null
+++ b/samples/bpf/hbm_out_kern.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2019 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Sample Host Bandwidth Manager (HBM) BPF program.
+ *
+ * A cgroup skb BPF egress program to limit cgroup output bandwidth.
+ * It uses a modified virtual token bucket queue to limit average
+ * egress bandwidth. The implementation uses credits instead of tokens.
+ * Negative credits imply that queueing would have happened (this is
+ * a virtual queue, so no queueing is done by it. However, queueing may
+ * occur at the actual qdisc (which is not used for rate limiting).
+ *
+ * This implementation uses 3 thresholds, one to start marking packets and
+ * the other two to drop packets:
+ *                                  CREDIT
+ *        - <--------------------------|------------------------> +
+ *              |    |          |      0
+ *              |  Large pkt    |
+ *              |  drop thresh  |
+ *   Small pkt drop             Mark threshold
+ *       thresh
+ *
+ * The effect of marking depends on the type of packet:
+ * a) If the packet is ECN enabled and it is a TCP packet, then the packet
+ *    is ECN marked.
+ * b) If the packet is a TCP packet, then we probabilistically call tcp_cwr
+ *    to reduce the congestion window. The current implementation uses a linear
+ *    distribution (0% probability at marking threshold, 100% probability
+ *    at drop threshold).
+ * c) If the packet is not a TCP packet, then it is dropped.
+ *
+ * If the credit is below the drop threshold, the packet is dropped. If it
+ * is a TCP packet, then it also calls tcp_cwr since packets dropped by
+ * by a cgroup skb BPF program do not automatically trigger a call to
+ * tcp_cwr in the current kernel code.
+ *
+ * This BPF program actually uses 2 drop thresholds, one threshold
+ * for larger packets (>= 120 bytes) and another for smaller packets. This
+ * protects smaller packets such as SYNs, ACKs, etc.
+ *
+ * The default bandwidth limit is set at 1Gbps but this can be changed by
+ * a user program through a shared BPF map. In addition, by default this BPF
+ * program does not limit connections using loopback. This behavior can be
+ * overwritten by the user program. There is also an option to calculate
+ * some statistics, such as percent of packets marked or dropped, which
+ * the user program can access.
+ *
+ * A latter patch provides such a program (hbm.c)
+ */
+
+#include "hbm_kern.h"
+
+SEC("cgroup_skb/egress")
+int _hbm_out_cg(struct __sk_buff *skb)
+{
+	struct hbm_pkt_info pkti;
+	int len = skb->len;
+	unsigned int queue_index = 0;
+	unsigned long long curtime;
+	int credit;
+	signed long long delta = 0, new_credit;
+	int max_credit = MAX_CREDIT;
+	bool congestion_flag = false;
+	bool drop_flag = false;
+	bool cwr_flag = false;
+	bool ecn_ce_flag = false;
+	struct hbm_vqueue *qdp;
+	struct hbm_queue_stats *qsp = NULL;
+	int rv = ALLOW_PKT;
+
+	qsp = bpf_map_lookup_elem(&queue_stats, &queue_index);
+	if (qsp != NULL && !qsp->loopback && (skb->ifindex == 1))
+		return ALLOW_PKT;
+
+	hbm_get_pkt_info(skb, &pkti);
+
+	// We may want to account for the length of headers in len
+	// calculation, like ETH header + overhead, specially if it
+	// is a gso packet. But I am not doing it right now.
+
+	qdp = bpf_get_local_storage(&queue_state, 0);
+	if (!qdp)
+		return ALLOW_PKT;
+	else if (qdp->lasttime == 0)
+		hbm_init_vqueue(qdp, 1024);
+
+	curtime = bpf_ktime_get_ns();
+
+	// Begin critical section
+	bpf_spin_lock(&qdp->lock);
+	credit = qdp->credit;
+	delta = curtime - qdp->lasttime;
+	/* delta < 0 implies that another process with a curtime greater
+	 * than ours beat us to the critical section and already added
+	 * the new credit, so we should not add it ourselves
+	 */
+	if (delta > 0) {
+		qdp->lasttime = curtime;
+		new_credit = credit + CREDIT_PER_NS(delta, qdp->rate);
+		if (new_credit > MAX_CREDIT)
+			credit = MAX_CREDIT;
+		else
+			credit = new_credit;
+	}
+	credit -= len;
+	qdp->credit = credit;
+	bpf_spin_unlock(&qdp->lock);
+	// End critical section
+
+	// Check if we should update rate
+	if (qsp != NULL && (qsp->rate * 128) != qdp->rate) {
+		qdp->rate = qsp->rate * 128;
+		bpf_printk("Updating rate: %d (1sec:%llu bits)\n",
+			   (int)qdp->rate,
+			   CREDIT_PER_NS(1000000000, qdp->rate) * 8);
+	}
+
+	// Set flags (drop, congestion, cwr)
+	// Dropping => we are congested, so ignore congestion flag
+	if (credit < -DROP_THRESH ||
+	    (len > LARGE_PKT_THRESH && credit < -LARGE_PKT_DROP_THRESH)) {
+		// Very congested, set drop packet
+		drop_flag = true;
+		if (pkti.ecn)
+			congestion_flag = true;
+		else if (pkti.is_tcp)
+			cwr_flag = true;
+	} else if (credit < 0) {
+		// Congested, set congestion flag
+		if (pkti.ecn || pkti.is_tcp) {
+			if (credit < -MARK_THRESH)
+				congestion_flag = true;
+			else
+				congestion_flag = false;
+		} else {
+			congestion_flag = true;
+		}
+	}
+
+	if (congestion_flag) {
+		if (bpf_skb_ecn_set_ce(skb)) {
+			ecn_ce_flag = true;
+		} else {
+			if (pkti.is_tcp) {
+				unsigned int rand = bpf_get_prandom_u32();
+
+				if (-credit >= MARK_THRESH +
+				    (rand % MARK_REGION_SIZE)) {
+					// Do congestion control
+					cwr_flag = true;
+				}
+			} else if (len > LARGE_PKT_THRESH) {
+				// Problem if too many small packets?
+				drop_flag = true;
+			}
+		}
+	}
+
+	if (qsp != NULL)
+		if (qsp->no_cn)
+			cwr_flag = false;
+
+	hbm_update_stats(qsp, len, curtime, congestion_flag, drop_flag,
+			 cwr_flag, ecn_ce_flag, &pkti, credit);
+
+	if (drop_flag) {
+		__sync_add_and_fetch(&(qdp->credit), len);
+		rv = DROP_PKT;
+	}
+
+	if (cwr_flag)
+		rv |= 2;
+	return rv;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/ibumad_kern.c b/samples/bpf/ibumad_kern.c
new file mode 100644
index 000000000..f07474c72
--- /dev/null
+++ b/samples/bpf/ibumad_kern.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+
+/*
+ * ibumad BPF sample kernel side
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Copyright(c) 2018 Ira Weiny, Intel Corporation
+ */
+
+#define KBUILD_MODNAME "ibumad_count_pkts_by_class"
+#include <uapi/linux/bpf.h>
+
+#include <bpf/bpf_helpers.h>
+
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32); /* class; u32 required */
+	__type(value, u64); /* count of mads read */
+	__uint(max_entries, 256); /* Room for all Classes */
+} read_count SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32); /* class; u32 required */
+	__type(value, u64); /* count of mads written */
+	__uint(max_entries, 256); /* Room for all Classes */
+} write_count SEC(".maps");
+
+#undef DEBUG
+#ifndef DEBUG
+#undef bpf_printk
+#define bpf_printk(fmt, ...)
+#endif
+
+/* Taken from the current format defined in
+ * include/trace/events/ib_umad.h
+ * and
+ * /sys/kernel/tracing/events/ib_umad/ib_umad_read/format
+ * /sys/kernel/tracing/events/ib_umad/ib_umad_write/format
+ */
+struct ib_umad_rw_args {
+	u64 pad;
+	u8 port_num;
+	u8 sl;
+	u8 path_bits;
+	u8 grh_present;
+	u32 id;
+	u32 status;
+	u32 timeout_ms;
+	u32 retires;
+	u32 length;
+	u32 qpn;
+	u32 qkey;
+	u8 gid_index;
+	u8 hop_limit;
+	u16 lid;
+	u16 attr_id;
+	u16 pkey_index;
+	u8 base_version;
+	u8 mgmt_class;
+	u8 class_version;
+	u8 method;
+	u32 flow_label;
+	u16 mad_status;
+	u16 class_specific;
+	u32 attr_mod;
+	u64 tid;
+	u8 gid[16];
+	u32 dev_index;
+	u8 traffic_class;
+};
+
+SEC("tracepoint/ib_umad/ib_umad_read_recv")
+int on_ib_umad_read_recv(struct ib_umad_rw_args *ctx)
+{
+	u64 zero = 0, *val;
+	u8 class = ctx->mgmt_class;
+
+	bpf_printk("ib_umad read recv : class 0x%x\n", class);
+
+	val = bpf_map_lookup_elem(&read_count, &class);
+	if (!val) {
+		bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
+		val = bpf_map_lookup_elem(&read_count, &class);
+		if (!val)
+			return 0;
+	}
+
+	(*val) += 1;
+
+	return 0;
+}
+SEC("tracepoint/ib_umad/ib_umad_read_send")
+int on_ib_umad_read_send(struct ib_umad_rw_args *ctx)
+{
+	u64 zero = 0, *val;
+	u8 class = ctx->mgmt_class;
+
+	bpf_printk("ib_umad read send : class 0x%x\n", class);
+
+	val = bpf_map_lookup_elem(&read_count, &class);
+	if (!val) {
+		bpf_map_update_elem(&read_count, &class, &zero, BPF_NOEXIST);
+		val = bpf_map_lookup_elem(&read_count, &class);
+		if (!val)
+			return 0;
+	}
+
+	(*val) += 1;
+
+	return 0;
+}
+SEC("tracepoint/ib_umad/ib_umad_write")
+int on_ib_umad_write(struct ib_umad_rw_args *ctx)
+{
+	u64 zero = 0, *val;
+	u8 class = ctx->mgmt_class;
+
+	bpf_printk("ib_umad write : class 0x%x\n", class);
+
+	val = bpf_map_lookup_elem(&write_count, &class);
+	if (!val) {
+		bpf_map_update_elem(&write_count, &class, &zero, BPF_NOEXIST);
+		val = bpf_map_lookup_elem(&write_count, &class);
+		if (!val)
+			return 0;
+	}
+
+	(*val) += 1;
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/ibumad_user.c b/samples/bpf/ibumad_user.c
new file mode 100644
index 000000000..d074c978a
--- /dev/null
+++ b/samples/bpf/ibumad_user.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+
+/*
+ * ibumad BPF sample user side
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Copyright(c) 2018 Ira Weiny, Intel Corporation
+ */
+
+#include <linux/bpf.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <limits.h>
+
+#include <getopt.h>
+#include <net/if.h>
+
+#include <bpf/bpf.h>
+#include "bpf_util.h"
+#include <bpf/libbpf.h>
+
+static struct bpf_link *tp_links[3];
+static struct bpf_object *obj;
+static int map_fd[2];
+static int tp_cnt;
+
+static void dump_counts(int fd)
+{
+	__u32 key;
+	__u64 value;
+
+	for (key = 0; key < 256; key++) {
+		if (bpf_map_lookup_elem(fd, &key, &value)) {
+			printf("failed to read key %u\n", key);
+			continue;
+		}
+		if (value)
+			printf("0x%02x : %llu\n", key, value);
+	}
+}
+
+static void dump_all_counts(void)
+{
+	printf("Read 'Class : count'\n");
+	dump_counts(map_fd[0]);
+	printf("Write 'Class : count'\n");
+	dump_counts(map_fd[1]);
+}
+
+static void dump_exit(int sig)
+{
+	dump_all_counts();
+	/* Detach tracepoints */
+	while (tp_cnt)
+		bpf_link__destroy(tp_links[--tp_cnt]);
+
+	bpf_object__close(obj);
+	exit(0);
+}
+
+static const struct option long_options[] = {
+	{"help",      no_argument,       NULL, 'h'},
+	{"delay",     required_argument, NULL, 'd'},
+};
+
+static void usage(char *cmd)
+{
+	printf("eBPF test program to count packets from various IP addresses\n"
+		"Usage: %s <options>\n"
+		"       --help,   -h  this menu\n"
+		"       --delay,  -d  <delay>  wait <delay> sec between prints [1 - 1000000]\n"
+		, cmd
+		);
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_program *prog;
+	unsigned long delay = 5;
+	char filename[256];
+	int longindex = 0;
+	int opt, err = -1;
+
+	while ((opt = getopt_long(argc, argv, "hd:rSw",
+				  long_options, &longindex)) != -1) {
+		switch (opt) {
+		case 'd':
+			delay = strtoul(optarg, NULL, 0);
+			if (delay == ULONG_MAX || delay < 0 ||
+			    delay > 1000000) {
+				fprintf(stderr, "ERROR: invalid delay : %s\n",
+					optarg);
+				usage(argv[0]);
+				return 1;
+			}
+			break;
+		default:
+		case 'h':
+			usage(argv[0]);
+			return 1;
+		}
+	}
+
+	/* Do one final dump when exiting */
+	signal(SIGINT, dump_exit);
+	signal(SIGTERM, dump_exit);
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return err;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "read_count");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "write_count");
+	if (map_fd[0] < 0 || map_fd[1] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		tp_links[tp_cnt] = bpf_program__attach(prog);
+		if (libbpf_get_error(tp_links[tp_cnt])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			tp_links[tp_cnt] = NULL;
+			goto cleanup;
+		}
+		tp_cnt++;
+	}
+
+	while (1) {
+		sleep(delay);
+		dump_all_counts();
+	}
+	err = 0;
+
+cleanup:
+	/* Detach tracepoints */
+	while (tp_cnt)
+		bpf_link__destroy(tp_links[--tp_cnt]);
+
+	bpf_object__close(obj);
+	return err;
+}
diff --git a/samples/bpf/lathist_kern.c b/samples/bpf/lathist_kern.c
new file mode 100644
index 000000000..4adfcbbe6
--- /dev/null
+++ b/samples/bpf/lathist_kern.c
@@ -0,0 +1,99 @@
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2015 BMW Car IT GmbH
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#define MAX_ENTRIES	20
+#define MAX_CPU		4
+
+/* We need to stick to static allocated memory (an array instead of
+ * hash table) because managing dynamic memory from the
+ * trace_preempt_[on|off] tracepoints hooks is not supported.
+ */
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, int);
+	__type(value, u64);
+	__uint(max_entries, MAX_CPU);
+} my_map SEC(".maps");
+
+SEC("kprobe/trace_preempt_off")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	int cpu = bpf_get_smp_processor_id();
+	u64 *ts = bpf_map_lookup_elem(&my_map, &cpu);
+
+	if (ts)
+		*ts = bpf_ktime_get_ns();
+
+	return 0;
+}
+
+static unsigned int log2(unsigned int v)
+{
+	unsigned int r;
+	unsigned int shift;
+
+	r = (v > 0xFFFF) << 4; v >>= r;
+	shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
+	shift = (v > 0xF) << 2; v >>= shift; r |= shift;
+	shift = (v > 0x3) << 1; v >>= shift; r |= shift;
+	r |= (v >> 1);
+
+	return r;
+}
+
+static unsigned int log2l(unsigned long v)
+{
+	unsigned int hi = v >> 32;
+
+	if (hi)
+		return log2(hi) + 32;
+	else
+		return log2(v);
+}
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, int);
+	__type(value, long);
+	__uint(max_entries, MAX_CPU * MAX_ENTRIES);
+} my_lat SEC(".maps");
+
+SEC("kprobe/trace_preempt_on")
+int bpf_prog2(struct pt_regs *ctx)
+{
+	u64 *ts, cur_ts, delta;
+	int key, cpu;
+	long *val;
+
+	cpu = bpf_get_smp_processor_id();
+	ts = bpf_map_lookup_elem(&my_map, &cpu);
+	if (!ts)
+		return 0;
+
+	cur_ts = bpf_ktime_get_ns();
+	delta = log2l(cur_ts - *ts);
+
+	if (delta > MAX_ENTRIES - 1)
+		delta = MAX_ENTRIES - 1;
+
+	key = cpu * MAX_ENTRIES + delta;
+	val = bpf_map_lookup_elem(&my_lat, &key);
+	if (val)
+		__sync_fetch_and_add((long *)val, 1);
+
+	return 0;
+
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/lathist_user.c b/samples/bpf/lathist_user.c
new file mode 100644
index 000000000..7d8ff2418
--- /dev/null
+++ b/samples/bpf/lathist_user.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ * Copyright (c) 2015 BMW Car IT GmbH
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+#define MAX_ENTRIES	20
+#define MAX_CPU		4
+#define MAX_STARS	40
+
+struct cpu_hist {
+	long data[MAX_ENTRIES];
+	long max;
+};
+
+static struct cpu_hist cpu_hist[MAX_CPU];
+
+static void stars(char *str, long val, long max, int width)
+{
+	int i;
+
+	for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
+		str[i] = '*';
+	if (val > max)
+		str[i - 1] = '+';
+	str[i] = '\0';
+}
+
+static void print_hist(void)
+{
+	char starstr[MAX_STARS];
+	struct cpu_hist *hist;
+	int i, j;
+
+	/* clear screen */
+	printf("\033[2J");
+
+	for (j = 0; j < MAX_CPU; j++) {
+		hist = &cpu_hist[j];
+
+		/* ignore CPUs without data (maybe offline?) */
+		if (hist->max == 0)
+			continue;
+
+		printf("CPU %d\n", j);
+		printf("      latency        : count     distribution\n");
+		for (i = 1; i <= MAX_ENTRIES; i++) {
+			stars(starstr, hist->data[i - 1], hist->max, MAX_STARS);
+			printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
+				(1l << i) >> 1, (1l << i) - 1,
+				hist->data[i - 1], MAX_STARS, starstr);
+		}
+	}
+}
+
+static void get_data(int fd)
+{
+	long key, value;
+	int c, i;
+
+	for (i = 0; i < MAX_CPU; i++)
+		cpu_hist[i].max = 0;
+
+	for (c = 0; c < MAX_CPU; c++) {
+		for (i = 0; i < MAX_ENTRIES; i++) {
+			key = c * MAX_ENTRIES + i;
+			bpf_map_lookup_elem(fd, &key, &value);
+
+			cpu_hist[c].data[i] = value;
+			if (value > cpu_hist[c].max)
+				cpu_hist[c].max = value;
+		}
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int map_fd, i = 0;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_lat");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[i] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[i] = NULL;
+			goto cleanup;
+		}
+		i++;
+	}
+
+	while (1) {
+		get_data(map_fd);
+		print_hist();
+		sleep(5);
+	}
+
+cleanup:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/lwt_len_hist.bpf.c b/samples/bpf/lwt_len_hist.bpf.c
new file mode 100644
index 000000000..dbab80e81
--- /dev/null
+++ b/samples/bpf/lwt_len_hist.bpf.c
@@ -0,0 +1,62 @@
+/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__type(key, u64);
+	__type(value, u64);
+	__uint(pinning, LIBBPF_PIN_BY_NAME);
+	__uint(max_entries, 1024);
+} lwt_len_hist_map SEC(".maps");
+
+static unsigned int log2(unsigned int v)
+{
+	unsigned int r;
+	unsigned int shift;
+
+	r = (v > 0xFFFF) << 4; v >>= r;
+	shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
+	shift = (v > 0xF) << 2; v >>= shift; r |= shift;
+	shift = (v > 0x3) << 1; v >>= shift; r |= shift;
+	r |= (v >> 1);
+	return r;
+}
+
+static unsigned int log2l(unsigned long v)
+{
+	unsigned int hi = v >> 32;
+	if (hi)
+		return log2(hi) + 32;
+	else
+		return log2(v);
+}
+
+SEC("len_hist")
+int do_len_hist(struct __sk_buff *skb)
+{
+	__u64 *value, key, init_val = 1;
+
+	key = log2l(skb->len);
+
+	value = bpf_map_lookup_elem(&lwt_len_hist_map, &key);
+	if (value)
+		__sync_fetch_and_add(value, 1);
+	else
+		bpf_map_update_elem(&lwt_len_hist_map, &key, &init_val, BPF_ANY);
+
+	return BPF_OK;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/lwt_len_hist.sh b/samples/bpf/lwt_len_hist.sh
new file mode 100755
index 000000000..381b2c634
--- /dev/null
+++ b/samples/bpf/lwt_len_hist.sh
@@ -0,0 +1,40 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+NS1=lwt_ns1
+VETH0=tst_lwt1a
+VETH1=tst_lwt1b
+BPF_PROG=lwt_len_hist.bpf.o
+TRACE_ROOT=/sys/kernel/tracing
+
+function cleanup {
+	# To reset saved histogram, remove pinned map
+	rm /sys/fs/bpf/tc/globals/lwt_len_hist_map
+	ip route del 192.168.253.2/32 dev $VETH0 2> /dev/null
+	ip link del $VETH0 2> /dev/null
+	ip link del $VETH1 2> /dev/null
+	ip netns exec $NS1 killall netserver
+	ip netns delete $NS1 2> /dev/null
+}
+
+cleanup
+
+ip netns add $NS1
+ip link add $VETH0 type veth peer name $VETH1
+ip link set dev $VETH0 up
+ip addr add 192.168.253.1/24 dev $VETH0
+ip link set $VETH1 netns $NS1
+ip netns exec $NS1 ip link set dev $VETH1 up
+ip netns exec $NS1 ip addr add 192.168.253.2/24 dev $VETH1
+ip netns exec $NS1 netserver
+
+echo 1 > ${TRACE_ROOT}/tracing_on
+cp /dev/null ${TRACE_ROOT}/trace
+ip route add 192.168.253.2/32 encap bpf out obj $BPF_PROG section len_hist dev $VETH0
+netperf -H 192.168.253.2 -t TCP_STREAM
+cat ${TRACE_ROOT}/trace | grep -v '^#'
+./lwt_len_hist
+cleanup
+echo 0 > ${TRACE_ROOT}/tracing_on
+
+exit 0
diff --git a/samples/bpf/lwt_len_hist_user.c b/samples/bpf/lwt_len_hist_user.c
new file mode 100644
index 000000000..430a4b7e3
--- /dev/null
+++ b/samples/bpf/lwt_len_hist_user.c
@@ -0,0 +1,77 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <arpa/inet.h>
+
+#include <bpf/bpf.h>
+#include "bpf_util.h"
+
+#define MAX_INDEX 64
+#define MAX_STARS 38
+
+static void stars(char *str, long val, long max, int width)
+{
+	int i;
+
+	for (i = 0; i < (width * val / max) - 1 && i < width - 1; i++)
+		str[i] = '*';
+	if (val > max)
+		str[i - 1] = '+';
+	str[i] = '\0';
+}
+
+int main(int argc, char **argv)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	const char *map_filename = "/sys/fs/bpf/tc/globals/lwt_len_hist_map";
+	uint64_t values[nr_cpus], sum, max_value = 0, data[MAX_INDEX] = {};
+	uint64_t key = 0, next_key, max_key = 0;
+	char starstr[MAX_STARS];
+	int i, map_fd;
+
+	map_fd = bpf_obj_get(map_filename);
+	if (map_fd < 0) {
+		fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
+			map_filename, strerror(errno), errno);
+		return -1;
+	}
+
+	while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
+		if (next_key >= MAX_INDEX) {
+			fprintf(stderr, "Key %lu out of bounds\n", next_key);
+			continue;
+		}
+
+		bpf_map_lookup_elem(map_fd, &next_key, values);
+
+		sum = 0;
+		for (i = 0; i < nr_cpus; i++)
+			sum += values[i];
+
+		data[next_key] = sum;
+		if (sum && next_key > max_key)
+			max_key = next_key;
+
+		if (sum > max_value)
+			max_value = sum;
+
+		key = next_key;
+	}
+
+	for (i = 1; i <= max_key + 1; i++) {
+		stars(starstr, data[i - 1], max_value, MAX_STARS);
+		printf("%8ld -> %-8ld : %-8ld |%-*s|\n",
+		       (1l << i) >> 1, (1l << i) - 1, data[i - 1],
+		       MAX_STARS, starstr);
+	}
+
+	close(map_fd);
+
+	return 0;
+}
diff --git a/samples/bpf/map_perf_test.bpf.c b/samples/bpf/map_perf_test.bpf.c
new file mode 100644
index 000000000..3cdeba2af
--- /dev/null
+++ b/samples/bpf/map_perf_test.bpf.c
@@ -0,0 +1,297 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "vmlinux.h"
+#include <errno.h>
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#define MAX_ENTRIES 1000
+#define MAX_NR_CPUS 1024
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+} hash_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 10000);
+} lru_hash_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 10000);
+	__uint(map_flags, BPF_F_NO_COMMON_LRU);
+} nocommon_lru_hash_map SEC(".maps");
+
+struct inner_lru {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+	__uint(map_flags, BPF_F_NUMA_NODE);
+	__uint(numa_node, 0);
+} inner_lru_hash_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+	__uint(max_entries, MAX_NR_CPUS);
+	__uint(key_size, sizeof(u32));
+	__array(values, struct inner_lru); /* use inner_lru as inner map */
+} array_of_lru_hashs SEC(".maps") = {
+	/* statically initialize the first element */
+	.values = { &inner_lru_hash_map },
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, MAX_ENTRIES);
+} percpu_hash_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+} hash_map_alloc SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, MAX_ENTRIES);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+} percpu_hash_map_alloc SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LPM_TRIE);
+	__uint(key_size, 8);
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, 10000);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+} lpm_trie_map_alloc SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+} array_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_LRU_HASH);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, MAX_ENTRIES);
+} lru_hash_lookup_map SEC(".maps");
+
+SEC("ksyscall/getuid")
+int BPF_KSYSCALL(stress_hmap)
+{
+	u32 key = bpf_get_current_pid_tgid();
+	long init_val = 1;
+	long *value;
+	int i;
+
+	for (i = 0; i < 10; i++) {
+		bpf_map_update_elem(&hash_map, &key, &init_val, BPF_ANY);
+		value = bpf_map_lookup_elem(&hash_map, &key);
+		if (value)
+			bpf_map_delete_elem(&hash_map, &key);
+	}
+
+	return 0;
+}
+
+SEC("ksyscall/geteuid")
+int BPF_KSYSCALL(stress_percpu_hmap)
+{
+	u32 key = bpf_get_current_pid_tgid();
+	long init_val = 1;
+	long *value;
+	int i;
+
+	for (i = 0; i < 10; i++) {
+		bpf_map_update_elem(&percpu_hash_map, &key, &init_val, BPF_ANY);
+		value = bpf_map_lookup_elem(&percpu_hash_map, &key);
+		if (value)
+			bpf_map_delete_elem(&percpu_hash_map, &key);
+	}
+	return 0;
+}
+
+SEC("ksyscall/getgid")
+int BPF_KSYSCALL(stress_hmap_alloc)
+{
+	u32 key = bpf_get_current_pid_tgid();
+	long init_val = 1;
+	long *value;
+	int i;
+
+	for (i = 0; i < 10; i++) {
+		bpf_map_update_elem(&hash_map_alloc, &key, &init_val, BPF_ANY);
+		value = bpf_map_lookup_elem(&hash_map_alloc, &key);
+		if (value)
+			bpf_map_delete_elem(&hash_map_alloc, &key);
+	}
+	return 0;
+}
+
+SEC("ksyscall/getegid")
+int BPF_KSYSCALL(stress_percpu_hmap_alloc)
+{
+	u32 key = bpf_get_current_pid_tgid();
+	long init_val = 1;
+	long *value;
+	int i;
+
+	for (i = 0; i < 10; i++) {
+		bpf_map_update_elem(&percpu_hash_map_alloc, &key, &init_val, BPF_ANY);
+		value = bpf_map_lookup_elem(&percpu_hash_map_alloc, &key);
+		if (value)
+			bpf_map_delete_elem(&percpu_hash_map_alloc, &key);
+	}
+	return 0;
+}
+SEC("ksyscall/connect")
+int BPF_KSYSCALL(stress_lru_hmap_alloc, int fd, struct sockaddr_in *uservaddr,
+		 int addrlen)
+{
+	char fmt[] = "Failed at stress_lru_hmap_alloc. ret:%dn";
+	union {
+		u16 dst6[8];
+		struct {
+			u16 magic0;
+			u16 magic1;
+			u16 tcase;
+			u16 unused16;
+			u32 unused32;
+			u32 key;
+		};
+	} test_params;
+	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)uservaddr;
+	u16 test_case;
+	long val = 1;
+	u32 key = 0;
+	int ret;
+
+	if (addrlen != sizeof(*in6))
+		return 0;
+
+	ret = bpf_probe_read_user(test_params.dst6, sizeof(test_params.dst6),
+				  &in6->sin6_addr);
+	if (ret)
+		goto done;
+
+	if (test_params.magic0 != 0xdead ||
+	    test_params.magic1 != 0xbeef)
+		return 0;
+
+	test_case = test_params.tcase;
+	if (test_case != 3)
+		key = bpf_get_prandom_u32();
+
+	if (test_case == 0) {
+		ret = bpf_map_update_elem(&lru_hash_map, &key, &val, BPF_ANY);
+	} else if (test_case == 1) {
+		ret = bpf_map_update_elem(&nocommon_lru_hash_map, &key, &val,
+					  BPF_ANY);
+	} else if (test_case == 2) {
+		void *nolocal_lru_map;
+		int cpu = bpf_get_smp_processor_id();
+
+		nolocal_lru_map = bpf_map_lookup_elem(&array_of_lru_hashs,
+						      &cpu);
+		if (!nolocal_lru_map) {
+			ret = -ENOENT;
+			goto done;
+		}
+
+		ret = bpf_map_update_elem(nolocal_lru_map, &key, &val,
+					  BPF_ANY);
+	} else if (test_case == 3) {
+		u32 i;
+
+		key = test_params.key;
+
+#pragma clang loop unroll(full)
+		for (i = 0; i < 32; i++) {
+			bpf_map_lookup_elem(&lru_hash_lookup_map, &key);
+			key++;
+		}
+	} else {
+		ret = -EINVAL;
+	}
+
+done:
+	if (ret)
+		bpf_trace_printk(fmt, sizeof(fmt), ret);
+
+	return 0;
+}
+
+SEC("ksyscall/gettid")
+int BPF_KSYSCALL(stress_lpm_trie_map_alloc)
+{
+	union {
+		u32 b32[2];
+		u8 b8[8];
+	} key;
+	unsigned int i;
+
+	key.b32[0] = 32;
+	key.b8[4] = 192;
+	key.b8[5] = 168;
+	key.b8[6] = 0;
+	key.b8[7] = 1;
+
+#pragma clang loop unroll(full)
+	for (i = 0; i < 32; ++i)
+		bpf_map_lookup_elem(&lpm_trie_map_alloc, &key);
+
+	return 0;
+}
+
+SEC("ksyscall/getpgid")
+int BPF_KSYSCALL(stress_hash_map_lookup)
+{
+	u32 key = 1, i;
+	long *value;
+
+#pragma clang loop unroll(full)
+	for (i = 0; i < 64; ++i)
+		value = bpf_map_lookup_elem(&hash_map, &key);
+
+	return 0;
+}
+
+SEC("ksyscall/getppid")
+int BPF_KSYSCALL(stress_array_map_lookup)
+{
+	u32 key = 1, i;
+	long *value;
+
+#pragma clang loop unroll(full)
+	for (i = 0; i < 64; ++i)
+		value = bpf_map_lookup_elem(&array_map, &key);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/map_perf_test_user.c b/samples/bpf/map_perf_test_user.c
new file mode 100644
index 000000000..07ff471ed
--- /dev/null
+++ b/samples/bpf/map_perf_test_user.c
@@ -0,0 +1,503 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#define _GNU_SOURCE
+#include <sched.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <asm/unistd.h>
+#include <unistd.h>
+#include <assert.h>
+#include <sys/wait.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <string.h>
+#include <time.h>
+#include <arpa/inet.h>
+#include <errno.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#define TEST_BIT(t) (1U << (t))
+#define MAX_NR_CPUS 1024
+
+static __u64 time_get_ns(void)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
+}
+
+enum test_type {
+	HASH_PREALLOC,
+	PERCPU_HASH_PREALLOC,
+	HASH_KMALLOC,
+	PERCPU_HASH_KMALLOC,
+	LRU_HASH_PREALLOC,
+	NOCOMMON_LRU_HASH_PREALLOC,
+	LPM_KMALLOC,
+	HASH_LOOKUP,
+	ARRAY_LOOKUP,
+	INNER_LRU_HASH_PREALLOC,
+	LRU_HASH_LOOKUP,
+	NR_TESTS,
+};
+
+const char *test_map_names[NR_TESTS] = {
+	[HASH_PREALLOC] = "hash_map",
+	[PERCPU_HASH_PREALLOC] = "percpu_hash_map",
+	[HASH_KMALLOC] = "hash_map_alloc",
+	[PERCPU_HASH_KMALLOC] = "percpu_hash_map_alloc",
+	[LRU_HASH_PREALLOC] = "lru_hash_map",
+	[NOCOMMON_LRU_HASH_PREALLOC] = "nocommon_lru_hash_map",
+	[LPM_KMALLOC] = "lpm_trie_map_alloc",
+	[HASH_LOOKUP] = "hash_map",
+	[ARRAY_LOOKUP] = "array_map",
+	[INNER_LRU_HASH_PREALLOC] = "inner_lru_hash_map",
+	[LRU_HASH_LOOKUP] = "lru_hash_lookup_map",
+};
+
+enum map_idx {
+	array_of_lru_hashs_idx,
+	hash_map_alloc_idx,
+	lru_hash_lookup_idx,
+	NR_IDXES,
+};
+
+static int map_fd[NR_IDXES];
+
+static int test_flags = ~0;
+static uint32_t num_map_entries;
+static uint32_t inner_lru_hash_size;
+static int lru_hash_lookup_test_entries = 32;
+static uint32_t max_cnt = 10000;
+
+static int check_test_flags(enum test_type t)
+{
+	return test_flags & TEST_BIT(t);
+}
+
+static void test_hash_prealloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getuid);
+	printf("%d:hash_map_perf pre-alloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static int pre_test_lru_hash_lookup(int tasks)
+{
+	int fd = map_fd[lru_hash_lookup_idx];
+	uint32_t key;
+	long val = 1;
+	int ret;
+
+	if (num_map_entries > lru_hash_lookup_test_entries)
+		lru_hash_lookup_test_entries = num_map_entries;
+
+	/* Populate the lru_hash_map for LRU_HASH_LOOKUP perf test.
+	 *
+	 * It is fine that the user requests for a map with
+	 * num_map_entries < 32 and some of the later lru hash lookup
+	 * may return not found.  For LRU map, we are not interested
+	 * in such small map performance.
+	 */
+	for (key = 0; key < lru_hash_lookup_test_entries; key++) {
+		ret = bpf_map_update_elem(fd, &key, &val, BPF_NOEXIST);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static void do_test_lru(enum test_type test, int cpu)
+{
+	static int inner_lru_map_fds[MAX_NR_CPUS];
+
+	struct sockaddr_in6 in6 = { .sin6_family = AF_INET6 };
+	const char *test_name;
+	__u64 start_time;
+	int i, ret;
+
+	if (test == INNER_LRU_HASH_PREALLOC && cpu) {
+		/* If CPU is not 0, create inner_lru hash map and insert the fd
+		 * value into the array_of_lru_hash map. In case of CPU 0,
+		 * 'inner_lru_hash_map' was statically inserted on the map init
+		 */
+		int outer_fd = map_fd[array_of_lru_hashs_idx];
+		unsigned int mycpu, mynode;
+		LIBBPF_OPTS(bpf_map_create_opts, opts,
+			.map_flags = BPF_F_NUMA_NODE,
+		);
+
+		assert(cpu < MAX_NR_CPUS);
+
+		ret = syscall(__NR_getcpu, &mycpu, &mynode, NULL);
+		assert(!ret);
+
+		opts.numa_node = mynode;
+		inner_lru_map_fds[cpu] =
+			bpf_map_create(BPF_MAP_TYPE_LRU_HASH,
+				       test_map_names[INNER_LRU_HASH_PREALLOC],
+				       sizeof(uint32_t),
+				       sizeof(long),
+				       inner_lru_hash_size, &opts);
+		if (inner_lru_map_fds[cpu] == -1) {
+			printf("cannot create BPF_MAP_TYPE_LRU_HASH %s(%d)\n",
+			       strerror(errno), errno);
+			exit(1);
+		}
+
+		ret = bpf_map_update_elem(outer_fd, &cpu,
+					  &inner_lru_map_fds[cpu],
+					  BPF_ANY);
+		if (ret) {
+			printf("cannot update ARRAY_OF_LRU_HASHS with key:%u. %s(%d)\n",
+			       cpu, strerror(errno), errno);
+			exit(1);
+		}
+	}
+
+	in6.sin6_addr.s6_addr16[0] = 0xdead;
+	in6.sin6_addr.s6_addr16[1] = 0xbeef;
+
+	if (test == LRU_HASH_PREALLOC) {
+		test_name = "lru_hash_map_perf";
+		in6.sin6_addr.s6_addr16[2] = 0;
+	} else if (test == NOCOMMON_LRU_HASH_PREALLOC) {
+		test_name = "nocommon_lru_hash_map_perf";
+		in6.sin6_addr.s6_addr16[2] = 1;
+	} else if (test == INNER_LRU_HASH_PREALLOC) {
+		test_name = "inner_lru_hash_map_perf";
+		in6.sin6_addr.s6_addr16[2] = 2;
+	} else if (test == LRU_HASH_LOOKUP) {
+		test_name = "lru_hash_lookup_perf";
+		in6.sin6_addr.s6_addr16[2] = 3;
+		in6.sin6_addr.s6_addr32[3] = 0;
+	} else {
+		assert(0);
+	}
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++) {
+		ret = connect(-1, (const struct sockaddr *)&in6, sizeof(in6));
+		assert(ret == -1 && errno == EBADF);
+		if (in6.sin6_addr.s6_addr32[3] <
+		    lru_hash_lookup_test_entries - 32)
+			in6.sin6_addr.s6_addr32[3] += 32;
+		else
+			in6.sin6_addr.s6_addr32[3] = 0;
+	}
+	printf("%d:%s pre-alloc %lld events per sec\n",
+	       cpu, test_name,
+	       max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_lru_hash_prealloc(int cpu)
+{
+	do_test_lru(LRU_HASH_PREALLOC, cpu);
+}
+
+static void test_nocommon_lru_hash_prealloc(int cpu)
+{
+	do_test_lru(NOCOMMON_LRU_HASH_PREALLOC, cpu);
+}
+
+static void test_inner_lru_hash_prealloc(int cpu)
+{
+	do_test_lru(INNER_LRU_HASH_PREALLOC, cpu);
+}
+
+static void test_lru_hash_lookup(int cpu)
+{
+	do_test_lru(LRU_HASH_LOOKUP, cpu);
+}
+
+static void test_percpu_hash_prealloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_geteuid);
+	printf("%d:percpu_hash_map_perf pre-alloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_hash_kmalloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getgid);
+	printf("%d:hash_map_perf kmalloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_percpu_hash_kmalloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getegid);
+	printf("%d:percpu_hash_map_perf kmalloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_lpm_kmalloc(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_gettid);
+	printf("%d:lpm_perf kmalloc %lld events per sec\n",
+	       cpu, max_cnt * 1000000000ll / (time_get_ns() - start_time));
+}
+
+static void test_hash_lookup(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getpgid, 0);
+	printf("%d:hash_lookup %lld lookups per sec\n",
+	       cpu, max_cnt * 1000000000ll * 64 / (time_get_ns() - start_time));
+}
+
+static void test_array_lookup(int cpu)
+{
+	__u64 start_time;
+	int i;
+
+	start_time = time_get_ns();
+	for (i = 0; i < max_cnt; i++)
+		syscall(__NR_getppid, 0);
+	printf("%d:array_lookup %lld lookups per sec\n",
+	       cpu, max_cnt * 1000000000ll * 64 / (time_get_ns() - start_time));
+}
+
+typedef int (*pre_test_func)(int tasks);
+const pre_test_func pre_test_funcs[] = {
+	[LRU_HASH_LOOKUP] = pre_test_lru_hash_lookup,
+};
+
+typedef void (*test_func)(int cpu);
+const test_func test_funcs[] = {
+	[HASH_PREALLOC] = test_hash_prealloc,
+	[PERCPU_HASH_PREALLOC] = test_percpu_hash_prealloc,
+	[HASH_KMALLOC] = test_hash_kmalloc,
+	[PERCPU_HASH_KMALLOC] = test_percpu_hash_kmalloc,
+	[LRU_HASH_PREALLOC] = test_lru_hash_prealloc,
+	[NOCOMMON_LRU_HASH_PREALLOC] = test_nocommon_lru_hash_prealloc,
+	[LPM_KMALLOC] = test_lpm_kmalloc,
+	[HASH_LOOKUP] = test_hash_lookup,
+	[ARRAY_LOOKUP] = test_array_lookup,
+	[INNER_LRU_HASH_PREALLOC] = test_inner_lru_hash_prealloc,
+	[LRU_HASH_LOOKUP] = test_lru_hash_lookup,
+};
+
+static int pre_test(int tasks)
+{
+	int i;
+
+	for (i = 0; i < NR_TESTS; i++) {
+		if (pre_test_funcs[i] && check_test_flags(i)) {
+			int ret = pre_test_funcs[i](tasks);
+
+			if (ret)
+				return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void loop(int cpu)
+{
+	cpu_set_t cpuset;
+	int i;
+
+	CPU_ZERO(&cpuset);
+	CPU_SET(cpu, &cpuset);
+	sched_setaffinity(0, sizeof(cpuset), &cpuset);
+
+	for (i = 0; i < NR_TESTS; i++) {
+		if (check_test_flags(i))
+			test_funcs[i](cpu);
+	}
+}
+
+static void run_perf_test(int tasks)
+{
+	pid_t pid[tasks];
+	int i;
+
+	assert(!pre_test(tasks));
+
+	for (i = 0; i < tasks; i++) {
+		pid[i] = fork();
+		if (pid[i] == 0) {
+			loop(i);
+			exit(0);
+		} else if (pid[i] == -1) {
+			printf("couldn't spawn #%d process\n", i);
+			exit(1);
+		}
+	}
+	for (i = 0; i < tasks; i++) {
+		int status;
+
+		assert(waitpid(pid[i], &status, 0) == pid[i]);
+		assert(status == 0);
+	}
+}
+
+static void fill_lpm_trie(void)
+{
+	struct bpf_lpm_trie_key_u8 *key;
+	unsigned long value = 0;
+	unsigned int i;
+	int r;
+
+	key = alloca(sizeof(*key) + 4);
+	key->prefixlen = 32;
+
+	for (i = 0; i < 512; ++i) {
+		key->prefixlen = rand() % 33;
+		key->data[0] = rand() & 0xff;
+		key->data[1] = rand() & 0xff;
+		key->data[2] = rand() & 0xff;
+		key->data[3] = rand() & 0xff;
+		r = bpf_map_update_elem(map_fd[hash_map_alloc_idx],
+					key, &value, 0);
+		assert(!r);
+	}
+
+	key->prefixlen = 32;
+	key->data[0] = 192;
+	key->data[1] = 168;
+	key->data[2] = 0;
+	key->data[3] = 1;
+	value = 128;
+
+	r = bpf_map_update_elem(map_fd[hash_map_alloc_idx], key, &value, 0);
+	assert(!r);
+}
+
+static void fixup_map(struct bpf_object *obj)
+{
+	struct bpf_map *map;
+	int i;
+
+	bpf_object__for_each_map(map, obj) {
+		const char *name = bpf_map__name(map);
+
+		/* Only change the max_entries for the enabled test(s) */
+		for (i = 0; i < NR_TESTS; i++) {
+			if (!strcmp(test_map_names[i], name) &&
+			    (check_test_flags(i))) {
+				bpf_map__set_max_entries(map, num_map_entries);
+				continue;
+			}
+		}
+	}
+
+	inner_lru_hash_size = num_map_entries;
+}
+
+int main(int argc, char **argv)
+{
+	int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+	struct bpf_link *links[8];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	struct bpf_map *map;
+	char filename[256];
+	int i = 0;
+
+	if (argc > 1)
+		test_flags = atoi(argv[1]) ? : test_flags;
+
+	if (argc > 2)
+		nr_cpus = atoi(argv[2]) ? : nr_cpus;
+
+	if (argc > 3)
+		num_map_entries = atoi(argv[3]);
+
+	if (argc > 4)
+		max_cnt = atoi(argv[4]);
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	map = bpf_object__find_map_by_name(obj, "inner_lru_hash_map");
+	if (libbpf_get_error(map)) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	inner_lru_hash_size = bpf_map__max_entries(map);
+	if (!inner_lru_hash_size) {
+		fprintf(stderr, "ERROR: failed to get map attribute\n");
+		goto cleanup;
+	}
+
+	/* resize BPF map prior to loading */
+	if (num_map_entries > 0)
+		fixup_map(obj);
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "array_of_lru_hashs");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "hash_map_alloc");
+	map_fd[2] = bpf_object__find_map_fd_by_name(obj, "lru_hash_lookup_map");
+	if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[i] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[i] = NULL;
+			goto cleanup;
+		}
+		i++;
+	}
+
+	fill_lpm_trie();
+
+	run_perf_test(nr_cpus);
+
+cleanup:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/net_shared.h b/samples/bpf/net_shared.h
new file mode 100644
index 000000000..88cc52461
--- /dev/null
+++ b/samples/bpf/net_shared.h
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef _NET_SHARED_H
+#define _NET_SHARED_H
+
+#define AF_INET		2
+#define AF_INET6	10
+
+#define ETH_ALEN 6
+#define ETH_P_802_3_MIN 0x0600
+#define ETH_P_8021Q 0x8100
+#define ETH_P_8021AD 0x88A8
+#define ETH_P_IP 0x0800
+#define ETH_P_IPV6 0x86DD
+#define ETH_P_ARP 0x0806
+#define IPPROTO_ICMPV6 58
+
+#define TC_ACT_OK		0
+#define TC_ACT_SHOT		2
+
+#define IFNAMSIZ 16
+
+#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
+	__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#define bpf_ntohs(x)		__builtin_bswap16(x)
+#define bpf_htons(x)		__builtin_bswap16(x)
+#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
+	__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#define bpf_ntohs(x)		(x)
+#define bpf_htons(x)		(x)
+#else
+# error "Endianness detection needs to be set up for your compiler?!"
+#endif
+
+#endif
diff --git a/samples/bpf/offwaketime.bpf.c b/samples/bpf/offwaketime.bpf.c
new file mode 100644
index 000000000..4a65ba76c
--- /dev/null
+++ b/samples/bpf/offwaketime.bpf.c
@@ -0,0 +1,141 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "vmlinux.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#ifndef PERF_MAX_STACK_DEPTH
+#define PERF_MAX_STACK_DEPTH         127
+#endif
+
+#define MINBLOCK_US	1
+#define MAX_ENTRIES	10000
+
+struct key_t {
+	char waker[TASK_COMM_LEN];
+	char target[TASK_COMM_LEN];
+	u32 wret;
+	u32 tret;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct key_t);
+	__type(value, u64);
+	__uint(max_entries, MAX_ENTRIES);
+} counts SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, u64);
+	__uint(max_entries, MAX_ENTRIES);
+} start SEC(".maps");
+
+struct wokeby_t {
+	char name[TASK_COMM_LEN];
+	u32 ret;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, struct wokeby_t);
+	__uint(max_entries, MAX_ENTRIES);
+} wokeby SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
+	__uint(max_entries, MAX_ENTRIES);
+} stackmap SEC(".maps");
+
+#define STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
+
+SEC("kprobe/try_to_wake_up")
+int waker(struct pt_regs *ctx)
+{
+	struct task_struct *p = (void *)PT_REGS_PARM1_CORE(ctx);
+	u32 pid = BPF_CORE_READ(p, pid);
+	struct wokeby_t woke;
+
+	bpf_get_current_comm(&woke.name, sizeof(woke.name));
+	woke.ret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
+
+	bpf_map_update_elem(&wokeby, &pid, &woke, BPF_ANY);
+	return 0;
+}
+
+static inline int update_counts(void *ctx, u32 pid, u64 delta)
+{
+	struct wokeby_t *woke;
+	u64 zero = 0, *val;
+	struct key_t key;
+
+	__builtin_memset(&key.waker, 0, sizeof(key.waker));
+	bpf_get_current_comm(&key.target, sizeof(key.target));
+	key.tret = bpf_get_stackid(ctx, &stackmap, STACKID_FLAGS);
+	key.wret = 0;
+
+	woke = bpf_map_lookup_elem(&wokeby, &pid);
+	if (woke) {
+		key.wret = woke->ret;
+		__builtin_memcpy(&key.waker, woke->name, sizeof(key.waker));
+		bpf_map_delete_elem(&wokeby, &pid);
+	}
+
+	val = bpf_map_lookup_elem(&counts, &key);
+	if (!val) {
+		bpf_map_update_elem(&counts, &key, &zero, BPF_NOEXIST);
+		val = bpf_map_lookup_elem(&counts, &key);
+		if (!val)
+			return 0;
+	}
+	(*val) += delta;
+	return 0;
+}
+
+#if 1
+/* taken from /sys/kernel/tracing/events/sched/sched_switch/format */
+SEC("tracepoint/sched/sched_switch")
+int oncpu(struct trace_event_raw_sched_switch *ctx)
+{
+	/* record previous thread sleep time */
+	u32 pid = ctx->prev_pid;
+#else
+SEC("kprobe.multi/finish_task_switch*")
+int oncpu(struct pt_regs *ctx)
+{
+	struct task_struct *p = (void *)PT_REGS_PARM1_CORE(ctx);
+	/* record previous thread sleep time */
+	u32 pid = BPF_CORE_READ(p, pid);
+#endif
+	u64 delta, ts, *tsp;
+
+	ts = bpf_ktime_get_ns();
+	bpf_map_update_elem(&start, &pid, &ts, BPF_ANY);
+
+	/* calculate current thread's delta time */
+	pid = bpf_get_current_pid_tgid();
+	tsp = bpf_map_lookup_elem(&start, &pid);
+	if (!tsp)
+		/* missed start or filtered */
+		return 0;
+
+	delta = bpf_ktime_get_ns() - *tsp;
+	bpf_map_delete_elem(&start, &pid);
+	delta = delta / 1000;
+	if (delta < MINBLOCK_US)
+		return 0;
+
+	return update_counts(ctx, pid, delta);
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/offwaketime_user.c b/samples/bpf/offwaketime_user.c
new file mode 100644
index 000000000..5557b5393
--- /dev/null
+++ b/samples/bpf/offwaketime_user.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <linux/perf_event.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "trace_helpers.h"
+
+#define PRINT_RAW_ADDR 0
+
+/* counts, stackmap */
+static int map_fd[2];
+
+static void print_ksym(__u64 addr)
+{
+	struct ksym *sym;
+
+	if (!addr)
+		return;
+	sym = ksym_search(addr);
+	if (!sym) {
+		printf("ksym not found. Is kallsyms loaded?\n");
+		return;
+	}
+
+	if (PRINT_RAW_ADDR)
+		printf("%s/%llx;", sym->name, addr);
+	else
+		printf("%s;", sym->name);
+}
+
+#define TASK_COMM_LEN 16
+
+struct key_t {
+	char waker[TASK_COMM_LEN];
+	char target[TASK_COMM_LEN];
+	__u32 wret;
+	__u32 tret;
+};
+
+static void print_stack(struct key_t *key, __u64 count)
+{
+	__u64 ip[PERF_MAX_STACK_DEPTH] = {};
+	static bool warned;
+	int i;
+
+	printf("%s;", key->target);
+	if (bpf_map_lookup_elem(map_fd[1], &key->tret, ip) != 0) {
+		printf("---;");
+	} else {
+		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
+			print_ksym(ip[i]);
+	}
+	printf("-;");
+	if (bpf_map_lookup_elem(map_fd[1], &key->wret, ip) != 0) {
+		printf("---;");
+	} else {
+		for (i = 0; i < PERF_MAX_STACK_DEPTH; i++)
+			print_ksym(ip[i]);
+	}
+	printf(";%s %lld\n", key->waker, count);
+
+	if ((key->tret == -EEXIST || key->wret == -EEXIST) && !warned) {
+		printf("stackmap collisions seen. Consider increasing size\n");
+		warned = true;
+	} else if (((int)(key->tret) < 0 || (int)(key->wret) < 0)) {
+		printf("err stackid %d %d\n", key->tret, key->wret);
+	}
+}
+
+static void print_stacks(int fd)
+{
+	struct key_t key = {}, next_key;
+	__u64 value;
+
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		bpf_map_lookup_elem(fd, &next_key, &value);
+		print_stack(&next_key, value);
+		key = next_key;
+	}
+}
+
+static void int_exit(int sig)
+{
+	print_stacks(map_fd[0]);
+	exit(0);
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_object *obj = NULL;
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	int delay = 1, i = 0;
+	char filename[256];
+
+	if (load_kallsyms()) {
+		printf("failed to process /proc/kallsyms\n");
+		return 2;
+	}
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		obj = NULL;
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");
+	if (map_fd[0] < 0 || map_fd[1] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	bpf_object__for_each_program(prog, obj) {
+		links[i] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[i] = NULL;
+			goto cleanup;
+		}
+		i++;
+	}
+
+	if (argc > 1)
+		delay = atoi(argv[1]);
+	sleep(delay);
+	print_stacks(map_fd[0]);
+
+cleanup:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/parse_ldabs.c b/samples/bpf/parse_ldabs.c
new file mode 100644
index 000000000..c6f65f90a
--- /dev/null
+++ b/samples/bpf/parse_ldabs.c
@@ -0,0 +1,43 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+#define DEFAULT_PKTGEN_UDP_PORT	9
+#define IP_MF			0x2000
+#define IP_OFFSET		0x1FFF
+
+static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
+{
+	return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
+		& (IP_MF | IP_OFFSET);
+}
+
+SEC("ldabs")
+int handle_ingress(struct __sk_buff *skb)
+{
+	__u64 troff = ETH_HLEN + sizeof(struct iphdr);
+
+	if (load_half(skb, offsetof(struct ethhdr, h_proto)) != ETH_P_IP)
+		return 0;
+	if (load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol)) != IPPROTO_UDP ||
+	    load_byte(skb, ETH_HLEN) != 0x45)
+		return 0;
+	if (ip_is_fragment(skb, ETH_HLEN))
+		return 0;
+	if (load_half(skb, troff + offsetof(struct udphdr, dest)) == DEFAULT_PKTGEN_UDP_PORT)
+		return TC_ACT_SHOT;
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/parse_simple.c b/samples/bpf/parse_simple.c
new file mode 100644
index 000000000..4a486cb1e
--- /dev/null
+++ b/samples/bpf/parse_simple.c
@@ -0,0 +1,49 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <uapi/linux/bpf.h>
+#include <net/ip.h>
+#include <bpf/bpf_helpers.h>
+
+#define DEFAULT_PKTGEN_UDP_PORT 9
+
+/* copy of 'struct ethhdr' without __packed */
+struct eth_hdr {
+	unsigned char   h_dest[ETH_ALEN];
+	unsigned char   h_source[ETH_ALEN];
+	unsigned short  h_proto;
+};
+
+SEC("simple")
+int handle_ingress(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	struct iphdr *iph = data + sizeof(*eth);
+	struct udphdr *udp = data + sizeof(*eth) + sizeof(*iph);
+	void *data_end = (void *)(long)skb->data_end;
+
+	/* single length check */
+	if (data + sizeof(*eth) + sizeof(*iph) + sizeof(*udp) > data_end)
+		return 0;
+
+	if (eth->h_proto != htons(ETH_P_IP))
+		return 0;
+	if (iph->protocol != IPPROTO_UDP || iph->ihl != 5)
+		return 0;
+	if (ip_is_fragment(iph))
+		return 0;
+	if (udp->dest == htons(DEFAULT_PKTGEN_UDP_PORT))
+		return TC_ACT_SHOT;
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/parse_varlen.c b/samples/bpf/parse_varlen.c
new file mode 100644
index 000000000..d8623846e
--- /dev/null
+++ b/samples/bpf/parse_varlen.c
@@ -0,0 +1,150 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <linux/if_ether.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <uapi/linux/bpf.h>
+#include <net/ip.h>
+#include <bpf/bpf_helpers.h>
+
+#define DEFAULT_PKTGEN_UDP_PORT 9
+#define DEBUG 0
+
+static int tcp(void *data, uint64_t tp_off, void *data_end)
+{
+	struct tcphdr *tcp = data + tp_off;
+
+	if (tcp + 1 > data_end)
+		return 0;
+	if (tcp->dest == htons(80) || tcp->source == htons(80))
+		return TC_ACT_SHOT;
+	return 0;
+}
+
+static int udp(void *data, uint64_t tp_off, void *data_end)
+{
+	struct udphdr *udp = data + tp_off;
+
+	if (udp + 1 > data_end)
+		return 0;
+	if (udp->dest == htons(DEFAULT_PKTGEN_UDP_PORT) ||
+	    udp->source == htons(DEFAULT_PKTGEN_UDP_PORT)) {
+		if (DEBUG) {
+			char fmt[] = "udp port 9 indeed\n";
+
+			bpf_trace_printk(fmt, sizeof(fmt));
+		}
+		return TC_ACT_SHOT;
+	}
+	return 0;
+}
+
+static int parse_ipv4(void *data, uint64_t nh_off, void *data_end)
+{
+	struct iphdr *iph;
+	uint64_t ihl_len;
+
+	iph = data + nh_off;
+	if (iph + 1 > data_end)
+		return 0;
+
+	if (ip_is_fragment(iph))
+		return 0;
+	ihl_len = iph->ihl * 4;
+
+	if (iph->protocol == IPPROTO_IPIP) {
+		iph = data + nh_off + ihl_len;
+		if (iph + 1 > data_end)
+			return 0;
+		ihl_len += iph->ihl * 4;
+	}
+
+	if (iph->protocol == IPPROTO_TCP)
+		return tcp(data, nh_off + ihl_len, data_end);
+	else if (iph->protocol == IPPROTO_UDP)
+		return udp(data, nh_off + ihl_len, data_end);
+	return 0;
+}
+
+static int parse_ipv6(void *data, uint64_t nh_off, void *data_end)
+{
+	struct ipv6hdr *ip6h;
+	struct iphdr *iph;
+	uint64_t ihl_len = sizeof(struct ipv6hdr);
+	uint64_t nexthdr;
+
+	ip6h = data + nh_off;
+	if (ip6h + 1 > data_end)
+		return 0;
+
+	nexthdr = ip6h->nexthdr;
+
+	if (nexthdr == IPPROTO_IPIP) {
+		iph = data + nh_off + ihl_len;
+		if (iph + 1 > data_end)
+			return 0;
+		ihl_len += iph->ihl * 4;
+		nexthdr = iph->protocol;
+	} else if (nexthdr == IPPROTO_IPV6) {
+		ip6h = data + nh_off + ihl_len;
+		if (ip6h + 1 > data_end)
+			return 0;
+		ihl_len += sizeof(struct ipv6hdr);
+		nexthdr = ip6h->nexthdr;
+	}
+
+	if (nexthdr == IPPROTO_TCP)
+		return tcp(data, nh_off + ihl_len, data_end);
+	else if (nexthdr == IPPROTO_UDP)
+		return udp(data, nh_off + ihl_len, data_end);
+	return 0;
+}
+
+SEC("varlen")
+int handle_ingress(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	struct ethhdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+	uint64_t h_proto, nh_off;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return 0;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == ETH_P_8021Q || h_proto == ETH_P_8021AD) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return 0;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	if (h_proto == ETH_P_8021Q || h_proto == ETH_P_8021AD) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			return 0;
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+	if (h_proto == htons(ETH_P_IP))
+		return parse_ipv4(data, nh_off, data_end);
+	else if (h_proto == htons(ETH_P_IPV6))
+		return parse_ipv6(data, nh_off, data_end);
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/run_cookie_uid_helper_example.sh b/samples/bpf/run_cookie_uid_helper_example.sh
new file mode 100755
index 000000000..fc6bc0451
--- /dev/null
+++ b/samples/bpf/run_cookie_uid_helper_example.sh
@@ -0,0 +1,15 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+local_dir="$(pwd)"
+root_dir=$local_dir/../..
+mnt_dir=$(mktemp -d --tmp)
+
+on_exit() {
+	iptables -D OUTPUT -m bpf --object-pinned ${mnt_dir}/bpf_prog -j ACCEPT
+	umount ${mnt_dir}
+	rm -r ${mnt_dir}
+}
+
+trap on_exit EXIT
+mount -t bpf bpf ${mnt_dir}
+./per_socket_stats_example ${mnt_dir}/bpf_prog $1
diff --git a/samples/bpf/sampleip_kern.c b/samples/bpf/sampleip_kern.c
new file mode 100644
index 000000000..a3f8a3998
--- /dev/null
+++ b/samples/bpf/sampleip_kern.c
@@ -0,0 +1,38 @@
+/* Copyright 2016 Netflix, Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#define MAX_IPS		8192
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u64);
+	__type(value, u32);
+	__uint(max_entries, MAX_IPS);
+} ip_map SEC(".maps");
+
+SEC("perf_event")
+int do_sample(struct bpf_perf_event_data *ctx)
+{
+	u64 ip;
+	u32 *value, init_val = 1;
+
+	ip = PT_REGS_IP(&ctx->regs);
+	value = bpf_map_lookup_elem(&ip_map, &ip);
+	if (value)
+		*value += 1;
+	else
+		/* E2BIG not tested for this example only */
+		bpf_map_update_elem(&ip_map, &ip, &init_val, BPF_NOEXIST);
+
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c
new file mode 100644
index 000000000..9283f4784
--- /dev/null
+++ b/samples/bpf/sampleip_user.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * sampleip: sample instruction pointer and frequency count in a BPF map.
+ *
+ * Copyright 2016 Netflix, Inc.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <linux/perf_event.h>
+#include <linux/ptrace.h>
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "perf-sys.h"
+#include "trace_helpers.h"
+
+#define DEFAULT_FREQ	99
+#define DEFAULT_SECS	5
+#define MAX_IPS		8192
+
+static int map_fd;
+static int nr_cpus;
+static long _text_addr;
+
+static void usage(void)
+{
+	printf("USAGE: sampleip [-F freq] [duration]\n");
+	printf("       -F freq    # sample frequency (Hertz), default 99\n");
+	printf("       duration   # sampling duration (seconds), default 5\n");
+}
+
+static int sampling_start(int freq, struct bpf_program *prog,
+			  struct bpf_link *links[])
+{
+	int i, pmu_fd;
+
+	struct perf_event_attr pe_sample_attr = {
+		.type = PERF_TYPE_SOFTWARE,
+		.freq = 1,
+		.sample_period = freq,
+		.config = PERF_COUNT_SW_CPU_CLOCK,
+		.inherit = 1,
+	};
+
+	for (i = 0; i < nr_cpus; i++) {
+		pmu_fd = sys_perf_event_open(&pe_sample_attr, -1 /* pid */, i,
+					    -1 /* group_fd */, 0 /* flags */);
+		if (pmu_fd < 0) {
+			fprintf(stderr, "ERROR: Initializing perf sampling\n");
+			return 1;
+		}
+		links[i] = bpf_program__attach_perf_event(prog, pmu_fd);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: Attach perf event\n");
+			links[i] = NULL;
+			close(pmu_fd);
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static void sampling_end(struct bpf_link *links[])
+{
+	int i;
+
+	for (i = 0; i < nr_cpus; i++)
+		bpf_link__destroy(links[i]);
+}
+
+struct ipcount {
+	__u64 ip;
+	__u32 count;
+};
+
+/* used for sorting */
+struct ipcount counts[MAX_IPS];
+
+static int count_cmp(const void *p1, const void *p2)
+{
+	return ((struct ipcount *)p1)->count - ((struct ipcount *)p2)->count;
+}
+
+static void print_ip_map(int fd)
+{
+	struct ksym *sym;
+	__u64 key, next_key;
+	__u32 value;
+	int i, max;
+
+	printf("%-19s %-32s %s\n", "ADDR", "KSYM", "COUNT");
+
+	/* fetch IPs and counts */
+	key = 0, i = 0;
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		bpf_map_lookup_elem(fd, &next_key, &value);
+		counts[i].ip = next_key;
+		counts[i++].count = value;
+		key = next_key;
+	}
+	max = i;
+
+	/* sort and print */
+	qsort(counts, max, sizeof(struct ipcount), count_cmp);
+	for (i = 0; i < max; i++) {
+		if (counts[i].ip > _text_addr) {
+			sym = ksym_search(counts[i].ip);
+			if (!sym) {
+				printf("ksym not found. Is kallsyms loaded?\n");
+				continue;
+			}
+
+			printf("0x%-17llx %-32s %u\n", counts[i].ip, sym->name,
+			       counts[i].count);
+		} else {
+			printf("0x%-17llx %-32s %u\n", counts[i].ip, "(user)",
+			       counts[i].count);
+		}
+	}
+
+	if (max == MAX_IPS) {
+		printf("WARNING: IP hash was full (max %d entries); ", max);
+		printf("may have dropped samples\n");
+	}
+}
+
+static void int_exit(int sig)
+{
+	printf("\n");
+	print_ip_map(map_fd);
+	exit(0);
+}
+
+int main(int argc, char **argv)
+{
+	int opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS, error = 1;
+	struct bpf_object *obj = NULL;
+	struct bpf_program *prog;
+	struct bpf_link **links;
+	char filename[256];
+
+	/* process arguments */
+	while ((opt = getopt(argc, argv, "F:h")) != -1) {
+		switch (opt) {
+		case 'F':
+			freq = atoi(optarg);
+			break;
+		case 'h':
+		default:
+			usage();
+			return 0;
+		}
+	}
+	if (argc - optind == 1)
+		secs = atoi(argv[optind]);
+	if (freq == 0 || secs == 0) {
+		usage();
+		return 1;
+	}
+
+	/* initialize kernel symbol translation */
+	if (load_kallsyms()) {
+		fprintf(stderr, "ERROR: loading /proc/kallsyms\n");
+		return 2;
+	}
+
+	/* used to determine whether the address is kernel space */
+	_text_addr = ksym_get_addr("_text");
+	if (!_text_addr) {
+		fprintf(stderr, "ERROR: no '_text' in /proc/kallsyms\n");
+		return 3;
+	}
+
+	/* create perf FDs for each CPU */
+	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+	links = calloc(nr_cpus, sizeof(struct bpf_link *));
+	if (!links) {
+		fprintf(stderr, "ERROR: malloc of links\n");
+		goto cleanup;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		obj = NULL;
+		goto cleanup;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "do_sample");
+	if (!prog) {
+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "ip_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	/* do sampling */
+	printf("Sampling at %d Hertz for %d seconds. Ctrl-C also ends.\n",
+	       freq, secs);
+	if (sampling_start(freq, prog, links) != 0)
+		goto cleanup;
+
+	sleep(secs);
+	error = 0;
+
+cleanup:
+	sampling_end(links);
+	/* output sample counts */
+	if (!error)
+		print_ip_map(map_fd);
+
+	free(links);
+	bpf_object__close(obj);
+	return error;
+}
diff --git a/samples/bpf/sock_example.c b/samples/bpf/sock_example.c
new file mode 100644
index 000000000..5b66f2401
--- /dev/null
+++ b/samples/bpf/sock_example.c
@@ -0,0 +1,111 @@
+/* eBPF example program:
+ * - creates arraymap in kernel with key 4 bytes and value 8 bytes
+ *
+ * - loads eBPF program:
+ *   r0 = skb->data[ETH_HLEN + offsetof(struct iphdr, protocol)];
+ *   *(u32*)(fp - 4) = r0;
+ *   // assuming packet is IPv4, lookup ip->proto in a map
+ *   value = bpf_map_lookup_elem(map_fd, fp - 4);
+ *   if (value)
+ *        (*(u64*)value) += 1;
+ *
+ * - attaches this program to loopback interface "lo" raw socket
+ *
+ * - every second user space reads map[tcp], map[udp], map[icmp] to see
+ *   how many packets of given protocol were seen on "lo"
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <assert.h>
+#include <linux/bpf.h>
+#include <string.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <linux/if_ether.h>
+#include <linux/ip.h>
+#include <stddef.h>
+#include <bpf/bpf.h>
+#include "bpf_insn.h"
+#include "sock_example.h"
+#include "bpf_util.h"
+
+char bpf_log_buf[BPF_LOG_BUF_SIZE];
+
+static int test_sock(void)
+{
+	int sock = -1, map_fd, prog_fd, i, key;
+	long long value = 0, tcp_cnt, udp_cnt, icmp_cnt;
+
+	map_fd = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, sizeof(key), sizeof(value),
+				256, NULL);
+	if (map_fd < 0) {
+		printf("failed to create map '%s'\n", strerror(errno));
+		goto cleanup;
+	}
+
+	struct bpf_insn prog[] = {
+		BPF_MOV64_REG(BPF_REG_6, BPF_REG_1),
+		BPF_LD_ABS(BPF_B, ETH_HLEN + offsetof(struct iphdr, protocol) /* R0 = ip->proto */),
+		BPF_STX_MEM(BPF_W, BPF_REG_10, BPF_REG_0, -4), /* *(u32 *)(fp - 4) = r0 */
+		BPF_MOV64_REG(BPF_REG_2, BPF_REG_10),
+		BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */
+		BPF_LD_MAP_FD(BPF_REG_1, map_fd),
+		BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem),
+		BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 2),
+		BPF_MOV64_IMM(BPF_REG_1, 1), /* r1 = 1 */
+		BPF_ATOMIC_OP(BPF_DW, BPF_ADD, BPF_REG_0, BPF_REG_1, 0),
+		BPF_MOV64_IMM(BPF_REG_0, 0), /* r0 = 0 */
+		BPF_EXIT_INSN(),
+	};
+	size_t insns_cnt = ARRAY_SIZE(prog);
+	LIBBPF_OPTS(bpf_prog_load_opts, opts,
+		.log_buf = bpf_log_buf,
+		.log_size = BPF_LOG_BUF_SIZE,
+	);
+
+	prog_fd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER, NULL, "GPL",
+				prog, insns_cnt, &opts);
+	if (prog_fd < 0) {
+		printf("failed to load prog '%s'\n", strerror(errno));
+		goto cleanup;
+	}
+
+	sock = open_raw_sock("lo");
+
+	if (setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
+		       sizeof(prog_fd)) < 0) {
+		printf("setsockopt %s\n", strerror(errno));
+		goto cleanup;
+	}
+
+	for (i = 0; i < 10; i++) {
+		key = IPPROTO_TCP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &tcp_cnt) == 0);
+
+		key = IPPROTO_UDP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &udp_cnt) == 0);
+
+		key = IPPROTO_ICMP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &icmp_cnt) == 0);
+
+		printf("TCP %lld UDP %lld ICMP %lld packets\n",
+		       tcp_cnt, udp_cnt, icmp_cnt);
+		sleep(1);
+	}
+
+cleanup:
+	/* maps, programs, raw sockets will auto cleanup on process exit */
+	return 0;
+}
+
+int main(void)
+{
+	FILE *f;
+
+	f = popen("ping -4 -c5 localhost", "r");
+	(void)f;
+
+	return test_sock();
+}
diff --git a/samples/bpf/sock_example.h b/samples/bpf/sock_example.h
new file mode 100644
index 000000000..a27d7579b
--- /dev/null
+++ b/samples/bpf/sock_example.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <stdlib.h>
+#include <stdio.h>
+#include <linux/unistd.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <linux/if_ether.h>
+#include <net/if.h>
+#include <linux/if_packet.h>
+#include <arpa/inet.h>
+
+static inline int open_raw_sock(const char *name)
+{
+	struct sockaddr_ll sll;
+	int sock;
+
+	sock = socket(PF_PACKET, SOCK_RAW | SOCK_NONBLOCK | SOCK_CLOEXEC, htons(ETH_P_ALL));
+	if (sock < 0) {
+		printf("cannot create raw socket\n");
+		return -1;
+	}
+
+	memset(&sll, 0, sizeof(sll));
+	sll.sll_family = AF_PACKET;
+	sll.sll_ifindex = if_nametoindex(name);
+	sll.sll_protocol = htons(ETH_P_ALL);
+	if (bind(sock, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
+		printf("bind to %s: %s\n", name, strerror(errno));
+		close(sock);
+		return -1;
+	}
+
+	return sock;
+}
diff --git a/samples/bpf/sockex1_kern.c b/samples/bpf/sockex1_kern.c
new file mode 100644
index 000000000..431c95646
--- /dev/null
+++ b/samples/bpf/sockex1_kern.c
@@ -0,0 +1,30 @@
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, long);
+	__uint(max_entries, 256);
+} my_map SEC(".maps");
+
+SEC("socket1")
+int bpf_prog1(struct __sk_buff *skb)
+{
+	int index = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
+	long *value;
+
+	if (skb->pkt_type != PACKET_OUTGOING)
+		return 0;
+
+	value = bpf_map_lookup_elem(&my_map, &index);
+	if (value)
+		__sync_fetch_and_add(value, skb->len);
+
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/sockex1_user.c b/samples/bpf/sockex1_user.c
new file mode 100644
index 000000000..9e8d39e24
--- /dev/null
+++ b/samples/bpf/sockex1_user.c
@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <assert.h>
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "sock_example.h"
+#include <unistd.h>
+#include <arpa/inet.h>
+
+int main(int ac, char **argv)
+{
+	struct bpf_object *obj;
+	struct bpf_program *prog;
+	int map_fd, prog_fd;
+	char filename[256];
+	int i, sock, err;
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj))
+		return 1;
+
+	prog = bpf_object__next_program(obj, NULL);
+	bpf_program__set_type(prog, BPF_PROG_TYPE_SOCKET_FILTER);
+
+	err = bpf_object__load(obj);
+	if (err)
+		return 1;
+
+	prog_fd = bpf_program__fd(prog);
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+
+	sock = open_raw_sock("lo");
+
+	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
+			  sizeof(prog_fd)) == 0);
+
+	f = popen("ping -4 -c5 localhost", "r");
+	(void) f;
+
+	for (i = 0; i < 5; i++) {
+		long long tcp_cnt, udp_cnt, icmp_cnt;
+		int key;
+
+		key = IPPROTO_TCP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &tcp_cnt) == 0);
+
+		key = IPPROTO_UDP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &udp_cnt) == 0);
+
+		key = IPPROTO_ICMP;
+		assert(bpf_map_lookup_elem(map_fd, &key, &icmp_cnt) == 0);
+
+		printf("TCP %lld UDP %lld ICMP %lld bytes\n",
+		       tcp_cnt, udp_cnt, icmp_cnt);
+		sleep(1);
+	}
+
+	return 0;
+}
diff --git a/samples/bpf/sockex2_kern.c b/samples/bpf/sockex2_kern.c
new file mode 100644
index 000000000..f93d9145a
--- /dev/null
+++ b/samples/bpf/sockex2_kern.c
@@ -0,0 +1,222 @@
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/if.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/if_tunnel.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+#define IP_MF		0x2000
+#define IP_OFFSET	0x1FFF
+
+struct vlan_hdr {
+	__be16 h_vlan_TCI;
+	__be16 h_vlan_encapsulated_proto;
+};
+
+struct flow_key_record {
+	__be32 src;
+	__be32 dst;
+	union {
+		__be32 ports;
+		__be16 port16[2];
+	};
+	__u16 thoff;
+	__u8 ip_proto;
+};
+
+static inline int proto_ports_offset(__u64 proto)
+{
+	switch (proto) {
+	case IPPROTO_TCP:
+	case IPPROTO_UDP:
+	case IPPROTO_ESP:
+	case IPPROTO_SCTP:
+	case IPPROTO_UDPLITE:
+		return 0;
+	case IPPROTO_AH:
+		return 4;
+	default:
+		return 0;
+	}
+}
+
+static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
+{
+	return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
+		& (IP_MF | IP_OFFSET);
+}
+
+static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
+{
+	__u64 w0 = load_word(ctx, off);
+	__u64 w1 = load_word(ctx, off + 4);
+	__u64 w2 = load_word(ctx, off + 8);
+	__u64 w3 = load_word(ctx, off + 12);
+
+	return (__u32)(w0 ^ w1 ^ w2 ^ w3);
+}
+
+static inline __u64 parse_ip(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
+			     struct flow_key_record *flow)
+{
+	__u64 verlen;
+
+	if (unlikely(ip_is_fragment(skb, nhoff)))
+		*ip_proto = 0;
+	else
+		*ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
+
+	if (*ip_proto != IPPROTO_GRE) {
+		flow->src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
+		flow->dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
+	}
+
+	verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
+	if (likely(verlen == 0x45))
+		nhoff += 20;
+	else
+		nhoff += (verlen & 0xF) << 2;
+
+	return nhoff;
+}
+
+static inline __u64 parse_ipv6(struct __sk_buff *skb, __u64 nhoff, __u64 *ip_proto,
+			       struct flow_key_record *flow)
+{
+	*ip_proto = load_byte(skb,
+			      nhoff + offsetof(struct ipv6hdr, nexthdr));
+	flow->src = ipv6_addr_hash(skb,
+				   nhoff + offsetof(struct ipv6hdr, saddr));
+	flow->dst = ipv6_addr_hash(skb,
+				   nhoff + offsetof(struct ipv6hdr, daddr));
+	nhoff += sizeof(struct ipv6hdr);
+
+	return nhoff;
+}
+
+static inline bool flow_dissector(struct __sk_buff *skb,
+				  struct flow_key_record *flow)
+{
+	__u64 nhoff = ETH_HLEN;
+	__u64 ip_proto;
+	__u64 proto = load_half(skb, 12);
+	int poff;
+
+	if (proto == ETH_P_8021AD) {
+		proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
+							h_vlan_encapsulated_proto));
+		nhoff += sizeof(struct vlan_hdr);
+	}
+
+	if (proto == ETH_P_8021Q) {
+		proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
+							h_vlan_encapsulated_proto));
+		nhoff += sizeof(struct vlan_hdr);
+	}
+
+	if (likely(proto == ETH_P_IP))
+		nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
+	else if (proto == ETH_P_IPV6)
+		nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
+	else
+		return false;
+
+	switch (ip_proto) {
+	case IPPROTO_GRE: {
+		struct gre_hdr {
+			__be16 flags;
+			__be16 proto;
+		};
+
+		__u64 gre_flags = load_half(skb,
+					    nhoff + offsetof(struct gre_hdr, flags));
+		__u64 gre_proto = load_half(skb,
+					    nhoff + offsetof(struct gre_hdr, proto));
+
+		if (gre_flags & (GRE_VERSION|GRE_ROUTING))
+			break;
+
+		proto = gre_proto;
+		nhoff += 4;
+		if (gre_flags & GRE_CSUM)
+			nhoff += 4;
+		if (gre_flags & GRE_KEY)
+			nhoff += 4;
+		if (gre_flags & GRE_SEQ)
+			nhoff += 4;
+
+		if (proto == ETH_P_8021Q) {
+			proto = load_half(skb,
+					  nhoff + offsetof(struct vlan_hdr,
+							   h_vlan_encapsulated_proto));
+			nhoff += sizeof(struct vlan_hdr);
+		}
+
+		if (proto == ETH_P_IP)
+			nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
+		else if (proto == ETH_P_IPV6)
+			nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
+		else
+			return false;
+		break;
+	}
+	case IPPROTO_IPIP:
+		nhoff = parse_ip(skb, nhoff, &ip_proto, flow);
+		break;
+	case IPPROTO_IPV6:
+		nhoff = parse_ipv6(skb, nhoff, &ip_proto, flow);
+		break;
+	default:
+		break;
+	}
+
+	flow->ip_proto = ip_proto;
+	poff = proto_ports_offset(ip_proto);
+	if (poff >= 0) {
+		nhoff += poff;
+		flow->ports = load_word(skb, nhoff);
+	}
+
+	flow->thoff = (__u16) nhoff;
+
+	return true;
+}
+
+struct pair {
+	long packets;
+	long bytes;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __be32);
+	__type(value, struct pair);
+	__uint(max_entries, 1024);
+} hash_map SEC(".maps");
+
+SEC("socket2")
+int bpf_prog2(struct __sk_buff *skb)
+{
+	struct flow_key_record flow = {};
+	struct pair *value;
+	u32 key;
+
+	if (!flow_dissector(skb, &flow))
+		return 0;
+
+	key = flow.dst;
+	value = bpf_map_lookup_elem(&hash_map, &key);
+	if (value) {
+		__sync_fetch_and_add(&value->packets, 1);
+		__sync_fetch_and_add(&value->bytes, skb->len);
+	} else {
+		struct pair val = {1, skb->len};
+
+		bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
+	}
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/sockex2_user.c b/samples/bpf/sockex2_user.c
new file mode 100644
index 000000000..2c1847133
--- /dev/null
+++ b/samples/bpf/sockex2_user.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <assert.h>
+#include <linux/bpf.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "sock_example.h"
+#include <unistd.h>
+#include <arpa/inet.h>
+
+struct pair {
+	__u64 packets;
+	__u64 bytes;
+};
+
+int main(int ac, char **argv)
+{
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	int map_fd, prog_fd;
+	char filename[256];
+	int i, sock, err;
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj))
+		return 1;
+
+	prog = bpf_object__next_program(obj, NULL);
+	bpf_program__set_type(prog, BPF_PROG_TYPE_SOCKET_FILTER);
+
+	err = bpf_object__load(obj);
+	if (err)
+		return 1;
+
+	prog_fd = bpf_program__fd(prog);
+	map_fd = bpf_object__find_map_fd_by_name(obj, "hash_map");
+
+	sock = open_raw_sock("lo");
+
+	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &prog_fd,
+			  sizeof(prog_fd)) == 0);
+
+	f = popen("ping -4 -c5 localhost", "r");
+	(void) f;
+
+	for (i = 0; i < 5; i++) {
+		int key = 0, next_key;
+		struct pair value;
+
+		while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
+			bpf_map_lookup_elem(map_fd, &next_key, &value);
+			printf("ip %s bytes %lld packets %lld\n",
+			       inet_ntoa((struct in_addr){htonl(next_key)}),
+			       value.bytes, value.packets);
+			key = next_key;
+		}
+		sleep(1);
+	}
+	return 0;
+}
diff --git a/samples/bpf/sockex3_kern.c b/samples/bpf/sockex3_kern.c
new file mode 100644
index 000000000..822c13242
--- /dev/null
+++ b/samples/bpf/sockex3_kern.c
@@ -0,0 +1,304 @@
+/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/if.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/if_tunnel.h>
+#include <uapi/linux/mpls.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+#define IP_MF		0x2000
+#define IP_OFFSET	0x1FFF
+
+#define PARSE_VLAN 1
+#define PARSE_MPLS 2
+#define PARSE_IP 3
+#define PARSE_IPV6 4
+
+struct vlan_hdr {
+	__be16 h_vlan_TCI;
+	__be16 h_vlan_encapsulated_proto;
+};
+
+struct flow_key_record {
+	__be32 src;
+	__be32 dst;
+	union {
+		__be32 ports;
+		__be16 port16[2];
+	};
+	__u32 ip_proto;
+};
+
+static inline void parse_eth_proto(struct __sk_buff *skb, u32 proto);
+
+static inline int ip_is_fragment(struct __sk_buff *ctx, __u64 nhoff)
+{
+	return load_half(ctx, nhoff + offsetof(struct iphdr, frag_off))
+		& (IP_MF | IP_OFFSET);
+}
+
+static inline __u32 ipv6_addr_hash(struct __sk_buff *ctx, __u64 off)
+{
+	__u64 w0 = load_word(ctx, off);
+	__u64 w1 = load_word(ctx, off + 4);
+	__u64 w2 = load_word(ctx, off + 8);
+	__u64 w3 = load_word(ctx, off + 12);
+
+	return (__u32)(w0 ^ w1 ^ w2 ^ w3);
+}
+
+struct globals {
+	struct flow_key_record flow;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, __u32);
+	__type(value, struct globals);
+	__uint(max_entries, 32);
+} percpu_map SEC(".maps");
+
+/* user poor man's per_cpu until native support is ready */
+static struct globals *this_cpu_globals(void)
+{
+	u32 key = bpf_get_smp_processor_id();
+
+	return bpf_map_lookup_elem(&percpu_map, &key);
+}
+
+/* some simple stats for user space consumption */
+struct pair {
+	__u64 packets;
+	__u64 bytes;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct flow_key_record);
+	__type(value, struct pair);
+	__uint(max_entries, 1024);
+} hash_map SEC(".maps");
+
+static void update_stats(struct __sk_buff *skb, struct globals *g)
+{
+	struct flow_key_record key = g->flow;
+	struct pair *value;
+
+	value = bpf_map_lookup_elem(&hash_map, &key);
+	if (value) {
+		__sync_fetch_and_add(&value->packets, 1);
+		__sync_fetch_and_add(&value->bytes, skb->len);
+	} else {
+		struct pair val = {1, skb->len};
+
+		bpf_map_update_elem(&hash_map, &key, &val, BPF_ANY);
+	}
+}
+
+static __always_inline void parse_ip_proto(struct __sk_buff *skb,
+					   struct globals *g, __u32 ip_proto)
+{
+	__u32 nhoff = skb->cb[0];
+	int poff;
+
+	switch (ip_proto) {
+	case IPPROTO_GRE: {
+		struct gre_hdr {
+			__be16 flags;
+			__be16 proto;
+		};
+
+		__u32 gre_flags = load_half(skb,
+					    nhoff + offsetof(struct gre_hdr, flags));
+		__u32 gre_proto = load_half(skb,
+					    nhoff + offsetof(struct gre_hdr, proto));
+
+		if (gre_flags & (GRE_VERSION|GRE_ROUTING))
+			break;
+
+		nhoff += 4;
+		if (gre_flags & GRE_CSUM)
+			nhoff += 4;
+		if (gre_flags & GRE_KEY)
+			nhoff += 4;
+		if (gre_flags & GRE_SEQ)
+			nhoff += 4;
+
+		skb->cb[0] = nhoff;
+		parse_eth_proto(skb, gre_proto);
+		break;
+	}
+	case IPPROTO_IPIP:
+		parse_eth_proto(skb, ETH_P_IP);
+		break;
+	case IPPROTO_IPV6:
+		parse_eth_proto(skb, ETH_P_IPV6);
+		break;
+	case IPPROTO_TCP:
+	case IPPROTO_UDP:
+		g->flow.ports = load_word(skb, nhoff);
+	case IPPROTO_ICMP:
+		g->flow.ip_proto = ip_proto;
+		update_stats(skb, g);
+		break;
+	default:
+		break;
+	}
+}
+
+SEC("socket")
+int bpf_func_ip(struct __sk_buff *skb)
+{
+	struct globals *g = this_cpu_globals();
+	__u32 nhoff, verlen, ip_proto;
+
+	if (!g)
+		return 0;
+
+	nhoff = skb->cb[0];
+
+	if (unlikely(ip_is_fragment(skb, nhoff)))
+		return 0;
+
+	ip_proto = load_byte(skb, nhoff + offsetof(struct iphdr, protocol));
+
+	if (ip_proto != IPPROTO_GRE) {
+		g->flow.src = load_word(skb, nhoff + offsetof(struct iphdr, saddr));
+		g->flow.dst = load_word(skb, nhoff + offsetof(struct iphdr, daddr));
+	}
+
+	verlen = load_byte(skb, nhoff + 0/*offsetof(struct iphdr, ihl)*/);
+	nhoff += (verlen & 0xF) << 2;
+
+	skb->cb[0] = nhoff;
+	parse_ip_proto(skb, g, ip_proto);
+	return 0;
+}
+
+SEC("socket")
+int bpf_func_ipv6(struct __sk_buff *skb)
+{
+	struct globals *g = this_cpu_globals();
+	__u32 nhoff, ip_proto;
+
+	if (!g)
+		return 0;
+
+	nhoff = skb->cb[0];
+
+	ip_proto = load_byte(skb,
+			     nhoff + offsetof(struct ipv6hdr, nexthdr));
+	g->flow.src = ipv6_addr_hash(skb,
+				     nhoff + offsetof(struct ipv6hdr, saddr));
+	g->flow.dst = ipv6_addr_hash(skb,
+				     nhoff + offsetof(struct ipv6hdr, daddr));
+	nhoff += sizeof(struct ipv6hdr);
+
+	skb->cb[0] = nhoff;
+	parse_ip_proto(skb, g, ip_proto);
+	return 0;
+}
+
+SEC("socket")
+int bpf_func_vlan(struct __sk_buff *skb)
+{
+	__u32 nhoff, proto;
+
+	nhoff = skb->cb[0];
+
+	proto = load_half(skb, nhoff + offsetof(struct vlan_hdr,
+						h_vlan_encapsulated_proto));
+	nhoff += sizeof(struct vlan_hdr);
+	skb->cb[0] = nhoff;
+
+	parse_eth_proto(skb, proto);
+
+	return 0;
+}
+
+SEC("socket")
+int bpf_func_mpls(struct __sk_buff *skb)
+{
+	__u32 nhoff, label;
+
+	nhoff = skb->cb[0];
+
+	label = load_word(skb, nhoff);
+	nhoff += sizeof(struct mpls_label);
+	skb->cb[0] = nhoff;
+
+	if (label & MPLS_LS_S_MASK) {
+		__u8 verlen = load_byte(skb, nhoff);
+		if ((verlen & 0xF0) == 4)
+			parse_eth_proto(skb, ETH_P_IP);
+		else
+			parse_eth_proto(skb, ETH_P_IPV6);
+	} else {
+		parse_eth_proto(skb, ETH_P_MPLS_UC);
+	}
+
+	return 0;
+}
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+	__uint(key_size, sizeof(u32));
+	__uint(max_entries, 8);
+	__array(values, u32 (void *));
+} prog_array_init SEC(".maps") = {
+	.values = {
+		[PARSE_VLAN] = (void *)&bpf_func_vlan,
+		[PARSE_IP]   = (void *)&bpf_func_ip,
+		[PARSE_IPV6] = (void *)&bpf_func_ipv6,
+		[PARSE_MPLS] = (void *)&bpf_func_mpls,
+	},
+};
+
+/* Protocol dispatch routine. It tail-calls next BPF program depending
+ * on eth proto. Note, we could have used ...
+ *
+ *   bpf_tail_call(skb, &prog_array_init, proto);
+ *
+ * ... but it would need large prog_array and cannot be optimised given
+ * the map key is not static.
+ */
+static inline void parse_eth_proto(struct __sk_buff *skb, u32 proto)
+{
+	switch (proto) {
+	case ETH_P_8021Q:
+	case ETH_P_8021AD:
+		bpf_tail_call(skb, &prog_array_init, PARSE_VLAN);
+		break;
+	case ETH_P_MPLS_UC:
+	case ETH_P_MPLS_MC:
+		bpf_tail_call(skb, &prog_array_init, PARSE_MPLS);
+		break;
+	case ETH_P_IP:
+		bpf_tail_call(skb, &prog_array_init, PARSE_IP);
+		break;
+	case ETH_P_IPV6:
+		bpf_tail_call(skb, &prog_array_init, PARSE_IPV6);
+		break;
+	}
+}
+
+SEC("socket")
+int main_prog(struct __sk_buff *skb)
+{
+	__u32 nhoff = ETH_HLEN;
+	__u32 proto = load_half(skb, 12);
+
+	skb->cb[0] = nhoff;
+	parse_eth_proto(skb, proto);
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/sockex3_user.c b/samples/bpf/sockex3_user.c
new file mode 100644
index 000000000..56044acbd
--- /dev/null
+++ b/samples/bpf/sockex3_user.c
@@ -0,0 +1,100 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <assert.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "sock_example.h"
+#include <unistd.h>
+#include <arpa/inet.h>
+
+struct flow_key_record {
+	__be32 src;
+	__be32 dst;
+	union {
+		__be32 ports;
+		__be16 port16[2];
+	};
+	__u32 ip_proto;
+};
+
+struct pair {
+	__u64 packets;
+	__u64 bytes;
+};
+
+int main(int argc, char **argv)
+{
+	int i, sock, fd, main_prog_fd, hash_map_fd;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	hash_map_fd = bpf_object__find_map_fd_by_name(obj, "hash_map");
+	if (hash_map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* find BPF main program */
+	main_prog_fd = 0;
+	bpf_object__for_each_program(prog, obj) {
+		fd = bpf_program__fd(prog);
+
+		if (!strcmp(bpf_program__name(prog), "main_prog"))
+			main_prog_fd = fd;
+	}
+
+	if (main_prog_fd == 0) {
+		fprintf(stderr, "ERROR: can't find main_prog\n");
+		goto cleanup;
+	}
+
+	sock = open_raw_sock("lo");
+
+	/* attach BPF program to socket */
+	assert(setsockopt(sock, SOL_SOCKET, SO_ATTACH_BPF, &main_prog_fd,
+			  sizeof(__u32)) == 0);
+
+	if (argc > 1)
+		f = popen("ping -4 -c5 localhost", "r");
+	else
+		f = popen("netperf -l 4 localhost", "r");
+	(void) f;
+
+	for (i = 0; i < 5; i++) {
+		struct flow_key_record key = {}, next_key;
+		struct pair value;
+
+		sleep(1);
+		printf("IP     src.port -> dst.port               bytes      packets\n");
+		while (bpf_map_get_next_key(hash_map_fd, &key, &next_key) == 0) {
+			bpf_map_lookup_elem(hash_map_fd, &next_key, &value);
+			printf("%s.%05d -> %s.%05d %12lld %12lld\n",
+			       inet_ntoa((struct in_addr){htonl(next_key.src)}),
+			       next_key.port16[0],
+			       inet_ntoa((struct in_addr){htonl(next_key.dst)}),
+			       next_key.port16[1],
+			       value.bytes, value.packets);
+			key = next_key;
+		}
+	}
+
+cleanup:
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/spintest.bpf.c b/samples/bpf/spintest.bpf.c
new file mode 100644
index 000000000..cba5a9d50
--- /dev/null
+++ b/samples/bpf/spintest.bpf.c
@@ -0,0 +1,60 @@
+/* Copyright (c) 2016, Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "vmlinux.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+#ifndef PERF_MAX_STACK_DEPTH
+#define PERF_MAX_STACK_DEPTH         127
+#endif
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, long);
+	__type(value, long);
+	__uint(max_entries, 1024);
+} my_map SEC(".maps");
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(key_size, sizeof(long));
+	__uint(value_size, sizeof(long));
+	__uint(max_entries, 1024);
+} my_map2 SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
+	__uint(max_entries, 10000);
+} stackmap SEC(".maps");
+
+#define PROG(foo) \
+int foo(struct pt_regs *ctx) \
+{ \
+	long v = PT_REGS_IP(ctx), *val; \
+\
+	val = bpf_map_lookup_elem(&my_map, &v); \
+	bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \
+	bpf_map_update_elem(&my_map2, &v, &v, BPF_ANY); \
+	bpf_map_delete_elem(&my_map2, &v); \
+	bpf_get_stackid(ctx, &stackmap, BPF_F_REUSE_STACKID); \
+	return 0; \
+}
+
+/* add kprobes to all possible *spin* functions */
+SEC("kprobe.multi/spin_*lock*")PROG(spin_lock)
+SEC("kprobe.multi/*_spin_on_owner")PROG(spin_on_owner)
+SEC("kprobe.multi/_raw_spin_*lock*")PROG(raw_spin_lock)
+
+/* and to inner bpf helpers */
+SEC("kprobe/htab_map_update_elem")PROG(p15)
+SEC("kprobe/__htab_percpu_map_update_elem")PROG(p16)
+SEC("kprobe/htab_map_alloc")PROG(p17)
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/spintest_user.c b/samples/bpf/spintest_user.c
new file mode 100644
index 000000000..55971edb1
--- /dev/null
+++ b/samples/bpf/spintest_user.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <assert.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "trace_helpers.h"
+
+int main(int ac, char **argv)
+{
+	struct bpf_object *obj = NULL;
+	struct bpf_link *links[20];
+	long key, next_key, value;
+	struct bpf_program *prog;
+	int map_fd, i, j = 0;
+	char filename[256];
+	struct ksym *sym;
+
+	if (load_kallsyms()) {
+		printf("failed to process /proc/kallsyms\n");
+		return 2;
+	}
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		obj = NULL;
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[j] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[j])) {
+			fprintf(stderr, "bpf_program__attach failed\n");
+			links[j] = NULL;
+			goto cleanup;
+		}
+		j++;
+	}
+
+	for (i = 0; i < 5; i++) {
+		key = 0;
+		printf("kprobing funcs:");
+		while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0) {
+			bpf_map_lookup_elem(map_fd, &next_key, &value);
+			assert(next_key == value);
+			sym = ksym_search(value);
+			key = next_key;
+			if (!sym) {
+				printf("ksym not found. Is kallsyms loaded?\n");
+				continue;
+			}
+
+			printf(" %s", sym->name);
+		}
+		if (key)
+			printf("\n");
+		key = 0;
+		while (bpf_map_get_next_key(map_fd, &key, &next_key) == 0)
+			bpf_map_delete_elem(map_fd, &next_key);
+		sleep(1);
+	}
+
+cleanup:
+	for (j--; j >= 0; j--)
+		bpf_link__destroy(links[j]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/syscall_nrs.c b/samples/bpf/syscall_nrs.c
new file mode 100644
index 000000000..a6e600f3d
--- /dev/null
+++ b/samples/bpf/syscall_nrs.c
@@ -0,0 +1,24 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <uapi/linux/unistd.h>
+#include <linux/kbuild.h>
+
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-prototypes"
+
+#define SYSNR(_NR) DEFINE(SYS ## _NR, _NR)
+
+void syscall_defines(void)
+{
+	COMMENT("Linux system call numbers.");
+	SYSNR(__NR_write);
+	SYSNR(__NR_read);
+#ifdef __NR_mmap2
+	SYSNR(__NR_mmap2);
+#endif
+#ifdef __NR_mmap
+	SYSNR(__NR_mmap);
+#endif
+
+}
+
+#pragma GCC diagnostic pop
diff --git a/samples/bpf/syscall_tp_kern.c b/samples/bpf/syscall_tp_kern.c
new file mode 100644
index 000000000..58fef969a
--- /dev/null
+++ b/samples/bpf/syscall_tp_kern.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Facebook
+ */
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+#if !defined(__aarch64__)
+struct syscalls_enter_open_args {
+	unsigned long long unused;
+	long syscall_nr;
+	long filename_ptr;
+	long flags;
+	long mode;
+};
+#endif
+
+struct syscalls_exit_open_args {
+	unsigned long long unused;
+	long syscall_nr;
+	long ret;
+};
+
+struct syscalls_enter_open_at_args {
+	unsigned long long unused;
+	long syscall_nr;
+	long long dfd;
+	long filename_ptr;
+	long flags;
+	long mode;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u32);
+	__uint(max_entries, 1);
+} enter_open_map SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, u32);
+	__uint(max_entries, 1);
+} exit_open_map SEC(".maps");
+
+static __always_inline void count(void *map)
+{
+	u32 key = 0;
+	u32 *value, init_val = 1;
+
+	value = bpf_map_lookup_elem(map, &key);
+	if (value)
+		*value += 1;
+	else
+		bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST);
+}
+
+#if !defined(__aarch64__)
+SEC("tracepoint/syscalls/sys_enter_open")
+int trace_enter_open(struct syscalls_enter_open_args *ctx)
+{
+	count(&enter_open_map);
+	return 0;
+}
+#endif
+
+SEC("tracepoint/syscalls/sys_enter_openat")
+int trace_enter_open_at(struct syscalls_enter_open_at_args *ctx)
+{
+	count(&enter_open_map);
+	return 0;
+}
+
+SEC("tracepoint/syscalls/sys_enter_openat2")
+int trace_enter_open_at2(struct syscalls_enter_open_at_args *ctx)
+{
+	count(&enter_open_map);
+	return 0;
+}
+
+#if !defined(__aarch64__)
+SEC("tracepoint/syscalls/sys_exit_open")
+int trace_enter_exit(struct syscalls_exit_open_args *ctx)
+{
+	count(&exit_open_map);
+	return 0;
+}
+#endif
+
+SEC("tracepoint/syscalls/sys_exit_openat")
+int trace_enter_exit_at(struct syscalls_exit_open_args *ctx)
+{
+	count(&exit_open_map);
+	return 0;
+}
+
+SEC("tracepoint/syscalls/sys_exit_openat2")
+int trace_enter_exit_at2(struct syscalls_exit_open_args *ctx)
+{
+	count(&exit_open_map);
+	return 0;
+}
diff --git a/samples/bpf/syscall_tp_user.c b/samples/bpf/syscall_tp_user.c
new file mode 100644
index 000000000..7a09ac74f
--- /dev/null
+++ b/samples/bpf/syscall_tp_user.c
@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2017 Facebook
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <linux/perf_event.h>
+#include <errno.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+/* This program verifies bpf attachment to tracepoint sys_enter_* and sys_exit_*.
+ * This requires kernel CONFIG_FTRACE_SYSCALLS to be set.
+ */
+
+static void usage(const char *cmd)
+{
+	printf("USAGE: %s [-i nr_tests] [-h]\n", cmd);
+	printf("       -i nr_tests      # rounds of test to run\n");
+	printf("       -h               # help\n");
+}
+
+static void verify_map(int map_id)
+{
+	__u32 key = 0;
+	__u32 val;
+
+	if (bpf_map_lookup_elem(map_id, &key, &val) != 0) {
+		fprintf(stderr, "map_lookup failed: %s\n", strerror(errno));
+		return;
+	}
+	if (val == 0) {
+		fprintf(stderr, "failed: map #%d returns value 0\n", map_id);
+		return;
+	}
+
+	printf("verify map:%d val: %d\n", map_id, val);
+
+	val = 0;
+	if (bpf_map_update_elem(map_id, &key, &val, BPF_ANY) != 0) {
+		fprintf(stderr, "map_update failed: %s\n", strerror(errno));
+		return;
+	}
+}
+
+static int test(char *filename, int nr_tests)
+{
+	int map0_fds[nr_tests], map1_fds[nr_tests], fd, i, j = 0;
+	struct bpf_link **links = NULL;
+	struct bpf_object *objs[nr_tests];
+	struct bpf_program *prog;
+
+	for (i = 0; i < nr_tests; i++) {
+		objs[i] = bpf_object__open_file(filename, NULL);
+		if (libbpf_get_error(objs[i])) {
+			fprintf(stderr, "opening BPF object file failed\n");
+			objs[i] = NULL;
+			goto cleanup;
+		}
+
+		/* One-time initialization */
+		if (!links) {
+			int nr_progs = 0;
+
+			bpf_object__for_each_program(prog, objs[i])
+				nr_progs += 1;
+
+			links = calloc(nr_progs * nr_tests, sizeof(struct bpf_link *));
+
+			if (!links)
+				goto cleanup;
+		}
+
+		/* load BPF program */
+		if (bpf_object__load(objs[i])) {
+			fprintf(stderr, "loading BPF object file failed\n");
+			goto cleanup;
+		}
+
+		map0_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
+							      "enter_open_map");
+		map1_fds[i] = bpf_object__find_map_fd_by_name(objs[i],
+							      "exit_open_map");
+		if (map0_fds[i] < 0 || map1_fds[i] < 0) {
+			fprintf(stderr, "finding a map in obj file failed\n");
+			goto cleanup;
+		}
+
+		bpf_object__for_each_program(prog, objs[i]) {
+			links[j] = bpf_program__attach(prog);
+			if (libbpf_get_error(links[j])) {
+				fprintf(stderr, "bpf_program__attach failed\n");
+				links[j] = NULL;
+				goto cleanup;
+			}
+			j++;
+		}
+		printf("prog #%d: map ids %d %d\n", i, map0_fds[i], map1_fds[i]);
+	}
+
+	/* current load_bpf_file has perf_event_open default pid = -1
+	 * and cpu = 0, which permits attached bpf execution on
+	 * all cpus for all pid's. bpf program execution ignores
+	 * cpu affinity.
+	 */
+	/* trigger some "open" operations */
+	fd = open(filename, O_RDONLY);
+	if (fd < 0) {
+		fprintf(stderr, "open failed: %s\n", strerror(errno));
+		return 1;
+	}
+	close(fd);
+
+	/* verify the map */
+	for (i = 0; i < nr_tests; i++) {
+		verify_map(map0_fds[i]);
+		verify_map(map1_fds[i]);
+	}
+
+cleanup:
+	if (links) {
+		for (j--; j >= 0; j--)
+			bpf_link__destroy(links[j]);
+
+		free(links);
+	}
+
+	for (i--; i >= 0; i--)
+		bpf_object__close(objs[i]);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int opt, nr_tests = 1;
+	char filename[256];
+
+	while ((opt = getopt(argc, argv, "i:h")) != -1) {
+		switch (opt) {
+		case 'i':
+			nr_tests = atoi(optarg);
+			break;
+		case 'h':
+		default:
+			usage(argv[0]);
+			return 0;
+		}
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	return test(filename, nr_tests);
+}
diff --git a/samples/bpf/task_fd_query_kern.c b/samples/bpf/task_fd_query_kern.c
new file mode 100644
index 000000000..186ac0a79
--- /dev/null
+++ b/samples/bpf/task_fd_query_kern.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/version.h>
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <bpf/bpf_helpers.h>
+
+SEC("kprobe/blk_mq_start_request")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	return 0;
+}
+
+SEC("kretprobe/__blk_account_io_done")
+int bpf_prog2(struct pt_regs *ctx)
+{
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/task_fd_query_user.c b/samples/bpf/task_fd_query_user.c
new file mode 100644
index 000000000..1e61f2180
--- /dev/null
+++ b/samples/bpf/task_fd_query_user.c
@@ -0,0 +1,423 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <string.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <linux/bpf.h>
+#include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <linux/perf_event.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "bpf_util.h"
+#include "perf-sys.h"
+#include "trace_helpers.h"
+
+static struct bpf_program *progs[2];
+static struct bpf_link *links[2];
+
+#define CHECK_PERROR_RET(condition) ({			\
+	int __ret = !!(condition);			\
+	if (__ret) {					\
+		printf("FAIL: %s:\n", __func__);	\
+		perror("    ");			\
+		return -1;				\
+	}						\
+})
+
+#define CHECK_AND_RET(condition) ({			\
+	int __ret = !!(condition);			\
+	if (__ret)					\
+		return -1;				\
+})
+
+static __u64 ptr_to_u64(void *ptr)
+{
+	return (__u64) (unsigned long) ptr;
+}
+
+#define PMU_TYPE_FILE "/sys/bus/event_source/devices/%s/type"
+static int bpf_find_probe_type(const char *event_type)
+{
+	char buf[256];
+	int fd, ret;
+
+	ret = snprintf(buf, sizeof(buf), PMU_TYPE_FILE, event_type);
+	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
+
+	fd = open(buf, O_RDONLY);
+	CHECK_PERROR_RET(fd < 0);
+
+	ret = read(fd, buf, sizeof(buf));
+	close(fd);
+	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
+
+	errno = 0;
+	ret = (int)strtol(buf, NULL, 10);
+	CHECK_PERROR_RET(errno);
+	return ret;
+}
+
+#define PMU_RETPROBE_FILE "/sys/bus/event_source/devices/%s/format/retprobe"
+static int bpf_get_retprobe_bit(const char *event_type)
+{
+	char buf[256];
+	int fd, ret;
+
+	ret = snprintf(buf, sizeof(buf), PMU_RETPROBE_FILE, event_type);
+	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
+
+	fd = open(buf, O_RDONLY);
+	CHECK_PERROR_RET(fd < 0);
+
+	ret = read(fd, buf, sizeof(buf));
+	close(fd);
+	CHECK_PERROR_RET(ret < 0 || ret >= sizeof(buf));
+	CHECK_PERROR_RET(strlen(buf) < strlen("config:"));
+
+	errno = 0;
+	ret = (int)strtol(buf + strlen("config:"), NULL, 10);
+	CHECK_PERROR_RET(errno);
+	return ret;
+}
+
+static int test_debug_fs_kprobe(int link_idx, const char *fn_name,
+				__u32 expected_fd_type)
+{
+	__u64 probe_offset, probe_addr;
+	__u32 len, prog_id, fd_type;
+	int err, event_fd;
+	char buf[256];
+
+	len = sizeof(buf);
+	event_fd = bpf_link__fd(links[link_idx]);
+	err = bpf_task_fd_query(getpid(), event_fd, 0, buf, &len,
+				&prog_id, &fd_type, &probe_offset,
+				&probe_addr);
+	if (err < 0) {
+		printf("FAIL: %s, for event_fd idx %d, fn_name %s\n",
+		       __func__, link_idx, fn_name);
+		perror("    :");
+		return -1;
+	}
+	if (strcmp(buf, fn_name) != 0 ||
+	    fd_type != expected_fd_type ||
+	    probe_offset != 0x0 || probe_addr != 0x0) {
+		printf("FAIL: bpf_trace_event_query(event_fd[%d]):\n",
+		       link_idx);
+		printf("buf: %s, fd_type: %u, probe_offset: 0x%llx,"
+		       " probe_addr: 0x%llx\n",
+		       buf, fd_type, probe_offset, probe_addr);
+		return -1;
+	}
+	return 0;
+}
+
+static int test_nondebug_fs_kuprobe_common(const char *event_type,
+	const char *name, __u64 offset, __u64 addr, bool is_return,
+	char *buf, __u32 *buf_len, __u32 *prog_id, __u32 *fd_type,
+	__u64 *probe_offset, __u64 *probe_addr)
+{
+	int is_return_bit = bpf_get_retprobe_bit(event_type);
+	int type = bpf_find_probe_type(event_type);
+	struct perf_event_attr attr = {};
+	struct bpf_link *link;
+	int fd, err = -1;
+
+	if (type < 0 || is_return_bit < 0) {
+		printf("FAIL: %s incorrect type (%d) or is_return_bit (%d)\n",
+			__func__, type, is_return_bit);
+		return err;
+	}
+
+	attr.sample_period = 1;
+	attr.wakeup_events = 1;
+	if (is_return)
+		attr.config |= 1 << is_return_bit;
+
+	if (name) {
+		attr.config1 = ptr_to_u64((void *)name);
+		attr.config2 = offset;
+	} else {
+		attr.config1 = 0;
+		attr.config2 = addr;
+	}
+	attr.size = sizeof(attr);
+	attr.type = type;
+
+	fd = sys_perf_event_open(&attr, -1, 0, -1, 0);
+	link = bpf_program__attach_perf_event(progs[0], fd);
+	if (libbpf_get_error(link)) {
+		printf("ERROR: bpf_program__attach_perf_event failed\n");
+		link = NULL;
+		close(fd);
+		goto cleanup;
+	}
+
+	CHECK_PERROR_RET(bpf_task_fd_query(getpid(), fd, 0, buf, buf_len,
+			 prog_id, fd_type, probe_offset, probe_addr) < 0);
+	err = 0;
+
+cleanup:
+	bpf_link__destroy(link);
+	return err;
+}
+
+static int test_nondebug_fs_probe(const char *event_type, const char *name,
+				  __u64 offset, __u64 addr, bool is_return,
+				  __u32 expected_fd_type,
+				  __u32 expected_ret_fd_type,
+				  char *buf, __u32 buf_len)
+{
+	__u64 probe_offset, probe_addr;
+	__u32 prog_id, fd_type;
+	int err;
+
+	err = test_nondebug_fs_kuprobe_common(event_type, name,
+					      offset, addr, is_return,
+					      buf, &buf_len, &prog_id,
+					      &fd_type, &probe_offset,
+					      &probe_addr);
+	if (err < 0) {
+		printf("FAIL: %s, "
+		       "for name %s, offset 0x%llx, addr 0x%llx, is_return %d\n",
+		       __func__, name ? name : "", offset, addr, is_return);
+		perror("    :");
+		return -1;
+	}
+	if ((is_return && fd_type != expected_ret_fd_type) ||
+	    (!is_return && fd_type != expected_fd_type)) {
+		printf("FAIL: %s, incorrect fd_type %u\n",
+		       __func__, fd_type);
+		return -1;
+	}
+	if (name) {
+		if (strcmp(name, buf) != 0) {
+			printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
+			return -1;
+		}
+		if (probe_offset != offset) {
+			printf("FAIL: %s, incorrect probe_offset 0x%llx\n",
+			       __func__, probe_offset);
+			return -1;
+		}
+	} else {
+		if (buf_len != 0) {
+			printf("FAIL: %s, incorrect buf %p\n",
+			       __func__, buf);
+			return -1;
+		}
+
+		if (probe_addr != addr) {
+			printf("FAIL: %s, incorrect probe_addr 0x%llx\n",
+			       __func__, probe_addr);
+			return -1;
+		}
+	}
+	return 0;
+}
+
+static int test_debug_fs_uprobe(char *binary_path, long offset, bool is_return)
+{
+	char buf[256], event_alias[sizeof("test_1234567890")];
+	const char *event_type = "uprobe";
+	struct perf_event_attr attr = {};
+	__u64 probe_offset, probe_addr;
+	__u32 len, prog_id, fd_type;
+	int err = -1, res, kfd, efd;
+	struct bpf_link *link;
+	ssize_t bytes;
+
+	snprintf(buf, sizeof(buf), "/sys/kernel/tracing/%s_events",
+		 event_type);
+	kfd = open(buf, O_WRONLY | O_TRUNC, 0);
+	CHECK_PERROR_RET(kfd < 0);
+
+	res = snprintf(event_alias, sizeof(event_alias), "test_%d", getpid());
+	CHECK_PERROR_RET(res < 0 || res >= sizeof(event_alias));
+
+	res = snprintf(buf, sizeof(buf), "%c:%ss/%s %s:0x%lx",
+		       is_return ? 'r' : 'p', event_type, event_alias,
+		       binary_path, offset);
+	CHECK_PERROR_RET(res < 0 || res >= sizeof(buf));
+	CHECK_PERROR_RET(write(kfd, buf, strlen(buf)) < 0);
+
+	close(kfd);
+	kfd = -1;
+
+	snprintf(buf, sizeof(buf), "/sys/kernel/tracing/events/%ss/%s/id",
+		 event_type, event_alias);
+	efd = open(buf, O_RDONLY, 0);
+	CHECK_PERROR_RET(efd < 0);
+
+	bytes = read(efd, buf, sizeof(buf));
+	CHECK_PERROR_RET(bytes <= 0 || bytes >= sizeof(buf));
+	close(efd);
+	buf[bytes] = '\0';
+
+	attr.config = strtol(buf, NULL, 0);
+	attr.type = PERF_TYPE_TRACEPOINT;
+	attr.sample_period = 1;
+	attr.wakeup_events = 1;
+
+	kfd = sys_perf_event_open(&attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC);
+	link = bpf_program__attach_perf_event(progs[0], kfd);
+	if (libbpf_get_error(link)) {
+		printf("ERROR: bpf_program__attach_perf_event failed\n");
+		link = NULL;
+		close(kfd);
+		goto cleanup;
+	}
+
+	len = sizeof(buf);
+	err = bpf_task_fd_query(getpid(), kfd, 0, buf, &len,
+				&prog_id, &fd_type, &probe_offset,
+				&probe_addr);
+	if (err < 0) {
+		printf("FAIL: %s, binary_path %s\n", __func__, binary_path);
+		perror("    :");
+		return -1;
+	}
+	if ((is_return && fd_type != BPF_FD_TYPE_URETPROBE) ||
+	    (!is_return && fd_type != BPF_FD_TYPE_UPROBE)) {
+		printf("FAIL: %s, incorrect fd_type %u\n", __func__,
+		       fd_type);
+		return -1;
+	}
+	if (strcmp(binary_path, buf) != 0) {
+		printf("FAIL: %s, incorrect buf %s\n", __func__, buf);
+		return -1;
+	}
+	if (probe_offset != offset) {
+		printf("FAIL: %s, incorrect probe_offset 0x%llx\n", __func__,
+		       probe_offset);
+		return -1;
+	}
+	err = 0;
+
+cleanup:
+	bpf_link__destroy(link);
+	return err;
+}
+
+int main(int argc, char **argv)
+{
+	extern char __executable_start;
+	char filename[256], buf[256];
+	__u64 uprobe_file_offset;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	int i = 0, err = -1;
+
+	if (load_kallsyms()) {
+		printf("failed to process /proc/kallsyms\n");
+		return err;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return err;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		progs[i] = prog;
+		links[i] = bpf_program__attach(progs[i]);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[i] = NULL;
+			goto cleanup;
+		}
+		i++;
+	}
+
+	/* test two functions in the corresponding *_kern.c file */
+	CHECK_AND_RET(test_debug_fs_kprobe(0, "blk_mq_start_request",
+					   BPF_FD_TYPE_KPROBE));
+	CHECK_AND_RET(test_debug_fs_kprobe(1, "__blk_account_io_done",
+					   BPF_FD_TYPE_KRETPROBE));
+
+	/* test nondebug fs kprobe */
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
+					     false, BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+#ifdef __x86_64__
+	/* set a kprobe on "bpf_check + 0x5", which is x64 specific */
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x5, 0x0,
+					     false, BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+#endif
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", "bpf_check", 0x0, 0x0,
+					     true, BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
+					     ksym_get_addr("bpf_check"), false,
+					     BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
+					     ksym_get_addr("bpf_check"), false,
+					     BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     NULL, 0));
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
+					     ksym_get_addr("bpf_check"), true,
+					     BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     buf, sizeof(buf)));
+	CHECK_AND_RET(test_nondebug_fs_probe("kprobe", NULL, 0x0,
+					     ksym_get_addr("bpf_check"), true,
+					     BPF_FD_TYPE_KPROBE,
+					     BPF_FD_TYPE_KRETPROBE,
+					     0, 0));
+
+	/* test nondebug fs uprobe */
+	/* the calculation of uprobe file offset is based on gcc 7.3.1 on x64
+	 * and the default linker script, which defines __executable_start as
+	 * the start of the .text section. The calculation could be different
+	 * on different systems with different compilers. The right way is
+	 * to parse the ELF file. We took a shortcut here.
+	 */
+	uprobe_file_offset = (unsigned long)main - (unsigned long)&__executable_start;
+	CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
+					     uprobe_file_offset, 0x0, false,
+					     BPF_FD_TYPE_UPROBE,
+					     BPF_FD_TYPE_URETPROBE,
+					     buf, sizeof(buf)));
+	CHECK_AND_RET(test_nondebug_fs_probe("uprobe", (char *)argv[0],
+					     uprobe_file_offset, 0x0, true,
+					     BPF_FD_TYPE_UPROBE,
+					     BPF_FD_TYPE_URETPROBE,
+					     buf, sizeof(buf)));
+
+	/* test debug fs uprobe */
+	CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
+					   false));
+	CHECK_AND_RET(test_debug_fs_uprobe((char *)argv[0], uprobe_file_offset,
+					   true));
+	err = 0;
+
+cleanup:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+
+	bpf_object__close(obj);
+	return err;
+}
diff --git a/samples/bpf/tc_l2_redirect.sh b/samples/bpf/tc_l2_redirect.sh
new file mode 100755
index 000000000..a28a8fc99
--- /dev/null
+++ b/samples/bpf/tc_l2_redirect.sh
@@ -0,0 +1,177 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+[[ -z $TC ]] && TC='tc'
+[[ -z $IP ]] && IP='ip'
+
+REDIRECT_USER='./tc_l2_redirect'
+REDIRECT_BPF='./tc_l2_redirect_kern.o'
+
+RP_FILTER=$(< /proc/sys/net/ipv4/conf/all/rp_filter)
+IPV6_DISABLED=$(< /proc/sys/net/ipv6/conf/all/disable_ipv6)
+IPV6_FORWARDING=$(< /proc/sys/net/ipv6/conf/all/forwarding)
+
+function config_common {
+	local tun_type=$1
+
+	$IP netns add ns1
+	$IP netns add ns2
+	$IP link add ve1 type veth peer name vens1
+	$IP link add ve2 type veth peer name vens2
+	$IP link set dev ve1 up
+	$IP link set dev ve2 up
+	$IP link set dev ve1 mtu 1500
+	$IP link set dev ve2 mtu 1500
+	$IP link set dev vens1 netns ns1
+	$IP link set dev vens2 netns ns2
+
+	$IP -n ns1 link set dev lo up
+	$IP -n ns1 link set dev vens1 up
+	$IP -n ns1 addr add 10.1.1.101/24 dev vens1
+	$IP -n ns1 addr add 2401:db01::65/64 dev vens1 nodad
+	$IP -n ns1 route add default via 10.1.1.1 dev vens1
+	$IP -n ns1 route add default via 2401:db01::1 dev vens1
+
+	$IP -n ns2 link set dev lo up
+	$IP -n ns2 link set dev vens2 up
+	$IP -n ns2 addr add 10.2.1.102/24 dev vens2
+	$IP -n ns2 addr add 2401:db02::66/64 dev vens2 nodad
+	$IP -n ns2 addr add 10.10.1.102 dev lo
+	$IP -n ns2 addr add 2401:face::66/64 dev lo nodad
+	$IP -n ns2 link add ipt2 type ipip local 10.2.1.102 remote 10.2.1.1
+	$IP -n ns2 link add ip6t2 type ip6tnl mode any local 2401:db02::66 remote 2401:db02::1
+	$IP -n ns2 link set dev ipt2 up
+	$IP -n ns2 link set dev ip6t2 up
+	$IP netns exec ns2 $TC qdisc add dev vens2 clsact
+	$IP netns exec ns2 $TC filter add dev vens2 ingress bpf da obj $REDIRECT_BPF sec drop_non_tun_vip
+	if [[ $tun_type == "ipip" ]]; then
+		$IP -n ns2 route add 10.1.1.0/24 dev ipt2
+		$IP netns exec ns2 sysctl -q -w net.ipv4.conf.all.rp_filter=0
+		$IP netns exec ns2 sysctl -q -w net.ipv4.conf.ipt2.rp_filter=0
+	else
+		$IP -n ns2 route add 10.1.1.0/24 dev ip6t2
+		$IP -n ns2 route add 2401:db01::/64 dev ip6t2
+		$IP netns exec ns2 sysctl -q -w net.ipv4.conf.all.rp_filter=0
+		$IP netns exec ns2 sysctl -q -w net.ipv4.conf.ip6t2.rp_filter=0
+	fi
+
+	$IP addr add 10.1.1.1/24 dev ve1
+	$IP addr add 2401:db01::1/64 dev ve1 nodad
+	$IP addr add 10.2.1.1/24 dev ve2
+	$IP addr add 2401:db02::1/64 dev ve2 nodad
+
+	$TC qdisc add dev ve2 clsact
+	$TC filter add dev ve2 ingress bpf da obj $REDIRECT_BPF sec l2_to_iptun_ingress_forward
+
+	sysctl -q -w net.ipv4.conf.all.rp_filter=0
+	sysctl -q -w net.ipv6.conf.all.forwarding=1
+	sysctl -q -w net.ipv6.conf.all.disable_ipv6=0
+}
+
+function cleanup {
+	set +e
+	[[ -z $DEBUG ]] || set +x
+	$IP netns delete ns1 >& /dev/null
+	$IP netns delete ns2 >& /dev/null
+	$IP link del ve1 >& /dev/null
+	$IP link del ve2 >& /dev/null
+	$IP link del ipt >& /dev/null
+	$IP link del ip6t >& /dev/null
+	sysctl -q -w net.ipv4.conf.all.rp_filter=$RP_FILTER
+	sysctl -q -w net.ipv6.conf.all.forwarding=$IPV6_FORWARDING
+	sysctl -q -w net.ipv6.conf.all.disable_ipv6=$IPV6_DISABLED
+	rm -f /sys/fs/bpf/tc/globals/tun_iface
+	[[ -z $DEBUG ]] || set -x
+	set -e
+}
+
+function l2_to_ipip {
+	echo -n "l2_to_ipip $1: "
+
+	local dir=$1
+
+	config_common ipip
+
+	$IP link add ipt type ipip external
+	$IP link set dev ipt up
+	sysctl -q -w net.ipv4.conf.ipt.rp_filter=0
+	sysctl -q -w net.ipv4.conf.ipt.forwarding=1
+
+	if [[ $dir == "egress" ]]; then
+		$IP route add 10.10.1.0/24 via 10.2.1.102 dev ve2
+		$TC filter add dev ve2 egress bpf da obj $REDIRECT_BPF sec l2_to_iptun_ingress_redirect
+		sysctl -q -w net.ipv4.conf.ve1.forwarding=1
+	else
+		$TC qdisc add dev ve1 clsact
+		$TC filter add dev ve1 ingress bpf da obj $REDIRECT_BPF sec l2_to_iptun_ingress_redirect
+	fi
+
+	$REDIRECT_USER -U /sys/fs/bpf/tc/globals/tun_iface -i $(< /sys/class/net/ipt/ifindex)
+
+	$IP netns exec ns1 ping -c1 10.10.1.102 >& /dev/null
+
+	if [[ $dir == "egress" ]]; then
+		# test direct egress to ve2 (i.e. not forwarding from
+		# ve1 to ve2).
+		ping -c1 10.10.1.102 >& /dev/null
+	fi
+
+	cleanup
+
+	echo "OK"
+}
+
+function l2_to_ip6tnl {
+	echo -n "l2_to_ip6tnl $1: "
+
+	local dir=$1
+
+	config_common ip6tnl
+
+	$IP link add ip6t type ip6tnl mode any external
+	$IP link set dev ip6t up
+	sysctl -q -w net.ipv4.conf.ip6t.rp_filter=0
+	sysctl -q -w net.ipv4.conf.ip6t.forwarding=1
+
+	if [[ $dir == "egress" ]]; then
+		$IP route add 10.10.1.0/24 via 10.2.1.102 dev ve2
+		$IP route add 2401:face::/64 via 2401:db02::66 dev ve2
+		$TC filter add dev ve2 egress bpf da obj $REDIRECT_BPF sec l2_to_ip6tun_ingress_redirect
+		sysctl -q -w net.ipv4.conf.ve1.forwarding=1
+	else
+		$TC qdisc add dev ve1 clsact
+		$TC filter add dev ve1 ingress bpf da obj $REDIRECT_BPF sec l2_to_ip6tun_ingress_redirect
+	fi
+
+	$REDIRECT_USER -U /sys/fs/bpf/tc/globals/tun_iface -i $(< /sys/class/net/ip6t/ifindex)
+
+	$IP netns exec ns1 ping -c1 10.10.1.102 >& /dev/null
+	$IP netns exec ns1 ping -6 -c1 2401:face::66 >& /dev/null
+
+	if [[ $dir == "egress" ]]; then
+		# test direct egress to ve2 (i.e. not forwarding from
+		# ve1 to ve2).
+		ping -c1 10.10.1.102 >& /dev/null
+		ping -6 -c1 2401:face::66 >& /dev/null
+	fi
+
+	cleanup
+
+	echo "OK"
+}
+
+cleanup
+test_names="l2_to_ipip l2_to_ip6tnl"
+test_dirs="ingress egress"
+if [[ $# -ge 2 ]]; then
+	test_names=$1
+	test_dirs=$2
+elif [[ $# -ge 1 ]]; then
+	test_names=$1
+fi
+
+for t in $test_names; do
+	for d in $test_dirs; do
+		$t $d
+	done
+done
diff --git a/samples/bpf/tc_l2_redirect_kern.c b/samples/bpf/tc_l2_redirect_kern.c
new file mode 100644
index 000000000..b19fa9b88
--- /dev/null
+++ b/samples/bpf/tc_l2_redirect_kern.c
@@ -0,0 +1,231 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/filter.h>
+#include <uapi/linux/pkt_cls.h>
+#include <net/ipv6.h>
+#include <bpf/bpf_helpers.h>
+
+#define _htonl __builtin_bswap32
+
+#define PIN_GLOBAL_NS		2
+struct bpf_elf_map {
+	__u32 type;
+	__u32 size_key;
+	__u32 size_value;
+	__u32 max_elem;
+	__u32 flags;
+	__u32 id;
+	__u32 pinning;
+};
+
+/* copy of 'struct ethhdr' without __packed */
+struct eth_hdr {
+	unsigned char   h_dest[ETH_ALEN];
+	unsigned char   h_source[ETH_ALEN];
+	unsigned short  h_proto;
+};
+
+struct bpf_elf_map SEC("maps") tun_iface = {
+	.type = BPF_MAP_TYPE_ARRAY,
+	.size_key = sizeof(int),
+	.size_value = sizeof(int),
+	.pinning = PIN_GLOBAL_NS,
+	.max_elem = 1,
+};
+
+static __always_inline bool is_vip_addr(__be16 eth_proto, __be32 daddr)
+{
+	if (eth_proto == htons(ETH_P_IP))
+		return (_htonl(0xffffff00) & daddr) == _htonl(0x0a0a0100);
+	else if (eth_proto == htons(ETH_P_IPV6))
+		return (daddr == _htonl(0x2401face));
+
+	return false;
+}
+
+SEC("l2_to_iptun_ingress_forward")
+int _l2_to_iptun_ingress_forward(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+	int key = 0, *ifindex;
+
+	if (data + sizeof(*eth) > data_end)
+		return TC_ACT_OK;
+
+	ifindex = bpf_map_lookup_elem(&tun_iface, &key);
+	if (!ifindex)
+		return TC_ACT_OK;
+
+	if (eth->h_proto == htons(ETH_P_IP)) {
+		char fmt4[] = "ingress forward to ifindex:%d daddr4:%x\n";
+		struct iphdr *iph = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*iph) > data_end)
+			return TC_ACT_OK;
+
+		if (iph->protocol != IPPROTO_IPIP)
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt4, sizeof(fmt4), *ifindex,
+				 _htonl(iph->daddr));
+		return bpf_redirect(*ifindex, BPF_F_INGRESS);
+	} else if (eth->h_proto == htons(ETH_P_IPV6)) {
+		char fmt6[] = "ingress forward to ifindex:%d daddr6:%x::%x\n";
+		struct ipv6hdr *ip6h = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
+			return TC_ACT_OK;
+
+		if (ip6h->nexthdr != IPPROTO_IPIP &&
+		    ip6h->nexthdr != IPPROTO_IPV6)
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt6, sizeof(fmt6), *ifindex,
+				 _htonl(ip6h->daddr.s6_addr32[0]),
+				 _htonl(ip6h->daddr.s6_addr32[3]));
+		return bpf_redirect(*ifindex, BPF_F_INGRESS);
+	}
+
+	return TC_ACT_OK;
+}
+
+SEC("l2_to_iptun_ingress_redirect")
+int _l2_to_iptun_ingress_redirect(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key tkey = {};
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+	int key = 0, *ifindex;
+
+	if (data + sizeof(*eth) > data_end)
+		return TC_ACT_OK;
+
+	ifindex = bpf_map_lookup_elem(&tun_iface, &key);
+	if (!ifindex)
+		return TC_ACT_OK;
+
+	if (eth->h_proto == htons(ETH_P_IP)) {
+		char fmt4[] = "e/ingress redirect daddr4:%x to ifindex:%d\n";
+		struct iphdr *iph = data + sizeof(*eth);
+		__be32 daddr = iph->daddr;
+
+		if (data + sizeof(*eth) + sizeof(*iph) > data_end)
+			return TC_ACT_OK;
+
+		if (!is_vip_addr(eth->h_proto, daddr))
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt4, sizeof(fmt4), _htonl(daddr), *ifindex);
+	} else {
+		return TC_ACT_OK;
+	}
+
+	tkey.tunnel_id = 10000;
+	tkey.tunnel_ttl = 64;
+	tkey.remote_ipv4 = 0x0a020166; /* 10.2.1.102 */
+	bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), 0);
+	return bpf_redirect(*ifindex, 0);
+}
+
+SEC("l2_to_ip6tun_ingress_redirect")
+int _l2_to_ip6tun_ingress_redirect(struct __sk_buff *skb)
+{
+	struct bpf_tunnel_key tkey = {};
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+	int key = 0, *ifindex;
+
+	if (data + sizeof(*eth) > data_end)
+		return TC_ACT_OK;
+
+	ifindex = bpf_map_lookup_elem(&tun_iface, &key);
+	if (!ifindex)
+		return TC_ACT_OK;
+
+	if (eth->h_proto == htons(ETH_P_IP)) {
+		char fmt4[] = "e/ingress redirect daddr4:%x to ifindex:%d\n";
+		struct iphdr *iph = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*iph) > data_end)
+			return TC_ACT_OK;
+
+		if (!is_vip_addr(eth->h_proto, iph->daddr))
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt4, sizeof(fmt4), _htonl(iph->daddr),
+				 *ifindex);
+	} else if (eth->h_proto == htons(ETH_P_IPV6)) {
+		char fmt6[] = "e/ingress redirect daddr6:%x to ifindex:%d\n";
+		struct ipv6hdr *ip6h = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
+			return TC_ACT_OK;
+
+		if (!is_vip_addr(eth->h_proto, ip6h->daddr.s6_addr32[0]))
+			return TC_ACT_OK;
+
+		bpf_trace_printk(fmt6, sizeof(fmt6),
+				 _htonl(ip6h->daddr.s6_addr32[0]), *ifindex);
+	} else {
+		return TC_ACT_OK;
+	}
+
+	tkey.tunnel_id = 10000;
+	tkey.tunnel_ttl = 64;
+	/* 2401:db02:0:0:0:0:0:66 */
+	tkey.remote_ipv6[0] = _htonl(0x2401db02);
+	tkey.remote_ipv6[1] = 0;
+	tkey.remote_ipv6[2] = 0;
+	tkey.remote_ipv6[3] = _htonl(0x00000066);
+	bpf_skb_set_tunnel_key(skb, &tkey, sizeof(tkey), BPF_F_TUNINFO_IPV6);
+	return bpf_redirect(*ifindex, 0);
+}
+
+SEC("drop_non_tun_vip")
+int _drop_non_tun_vip(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	struct eth_hdr *eth = data;
+	void *data_end = (void *)(long)skb->data_end;
+
+	if (data + sizeof(*eth) > data_end)
+		return TC_ACT_OK;
+
+	if (eth->h_proto == htons(ETH_P_IP)) {
+		struct iphdr *iph = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*iph) > data_end)
+			return TC_ACT_OK;
+
+		if (is_vip_addr(eth->h_proto, iph->daddr))
+			return TC_ACT_SHOT;
+	} else if (eth->h_proto == htons(ETH_P_IPV6)) {
+		struct ipv6hdr *ip6h = data + sizeof(*eth);
+
+		if (data + sizeof(*eth) + sizeof(*ip6h) > data_end)
+			return TC_ACT_OK;
+
+		if (is_vip_addr(eth->h_proto, ip6h->daddr.s6_addr32[0]))
+			return TC_ACT_SHOT;
+	}
+
+	return TC_ACT_OK;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tc_l2_redirect_user.c b/samples/bpf/tc_l2_redirect_user.c
new file mode 100644
index 000000000..d11a6e1e9
--- /dev/null
+++ b/samples/bpf/tc_l2_redirect_user.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <linux/unistd.h>
+#include <linux/bpf.h>
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+
+#include <bpf/bpf.h>
+
+static void usage(void)
+{
+	printf("Usage: tc_l2_ipip_redirect [...]\n");
+	printf("       -U <file>   Update an already pinned BPF array\n");
+	printf("       -i <ifindex> Interface index\n");
+	printf("       -h          Display this help\n");
+}
+
+int main(int argc, char **argv)
+{
+	const char *pinned_file = NULL;
+	int ifindex = -1;
+	int array_key = 0;
+	int array_fd = -1;
+	int ret = -1;
+	int opt;
+
+	while ((opt = getopt(argc, argv, "F:U:i:")) != -1) {
+		switch (opt) {
+		/* General args */
+		case 'U':
+			pinned_file = optarg;
+			break;
+		case 'i':
+			ifindex = atoi(optarg);
+			break;
+		default:
+			usage();
+			goto out;
+		}
+	}
+
+	if (ifindex < 0 || !pinned_file) {
+		usage();
+		goto out;
+	}
+
+	array_fd = bpf_obj_get(pinned_file);
+	if (array_fd < 0) {
+		fprintf(stderr, "bpf_obj_get(%s): %s(%d)\n",
+			pinned_file, strerror(errno), errno);
+		goto out;
+	}
+
+	/* bpf_tunnel_key.remote_ipv4 expects host byte orders */
+	ret = bpf_map_update_elem(array_fd, &array_key, &ifindex, 0);
+	if (ret) {
+		perror("bpf_map_update_elem");
+		goto out;
+	}
+
+out:
+	if (array_fd != -1)
+		close(array_fd);
+	return ret;
+}
diff --git a/samples/bpf/tcbpf1_kern.c b/samples/bpf/tcbpf1_kern.c
new file mode 100644
index 000000000..e9356130f
--- /dev/null
+++ b/samples/bpf/tcbpf1_kern.c
@@ -0,0 +1,91 @@
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/in.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/filter.h>
+#include <uapi/linux/pkt_cls.h>
+#include <bpf/bpf_helpers.h>
+#include "bpf_legacy.h"
+
+/* compiler workaround */
+#define _htonl __builtin_bswap32
+
+static inline void set_dst_mac(struct __sk_buff *skb, char *mac)
+{
+	bpf_skb_store_bytes(skb, 0, mac, ETH_ALEN, 1);
+}
+
+#define IP_CSUM_OFF (ETH_HLEN + offsetof(struct iphdr, check))
+#define TOS_OFF (ETH_HLEN + offsetof(struct iphdr, tos))
+
+static inline void set_ip_tos(struct __sk_buff *skb, __u8 new_tos)
+{
+	__u8 old_tos = load_byte(skb, TOS_OFF);
+
+	bpf_l3_csum_replace(skb, IP_CSUM_OFF, htons(old_tos), htons(new_tos), 2);
+	bpf_skb_store_bytes(skb, TOS_OFF, &new_tos, sizeof(new_tos), 0);
+}
+
+#define TCP_CSUM_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, check))
+#define IP_SRC_OFF (ETH_HLEN + offsetof(struct iphdr, saddr))
+
+#define IS_PSEUDO 0x10
+
+static inline void set_tcp_ip_src(struct __sk_buff *skb, __u32 new_ip)
+{
+	__u32 old_ip = _htonl(load_word(skb, IP_SRC_OFF));
+
+	bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_ip, new_ip, IS_PSEUDO | sizeof(new_ip));
+	bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
+	bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
+}
+
+#define TCP_DPORT_OFF (ETH_HLEN + sizeof(struct iphdr) + offsetof(struct tcphdr, dest))
+static inline void set_tcp_dest_port(struct __sk_buff *skb, __u16 new_port)
+{
+	__u16 old_port = htons(load_half(skb, TCP_DPORT_OFF));
+
+	bpf_l4_csum_replace(skb, TCP_CSUM_OFF, old_port, new_port, sizeof(new_port));
+	bpf_skb_store_bytes(skb, TCP_DPORT_OFF, &new_port, sizeof(new_port), 0);
+}
+
+SEC("classifier")
+int bpf_prog1(struct __sk_buff *skb)
+{
+	__u8 proto = load_byte(skb, ETH_HLEN + offsetof(struct iphdr, protocol));
+	long *value;
+
+	if (proto == IPPROTO_TCP) {
+		set_ip_tos(skb, 8);
+		set_tcp_ip_src(skb, 0xA010101);
+		set_tcp_dest_port(skb, 5001);
+	}
+
+	return 0;
+}
+SEC("redirect_xmit")
+int _redirect_xmit(struct __sk_buff *skb)
+{
+	return bpf_redirect(skb->ifindex + 1, 0);
+}
+SEC("redirect_recv")
+int _redirect_recv(struct __sk_buff *skb)
+{
+	return bpf_redirect(skb->ifindex + 1, 1);
+}
+SEC("clone_redirect_xmit")
+int _clone_redirect_xmit(struct __sk_buff *skb)
+{
+	bpf_clone_redirect(skb, skb->ifindex + 1, 0);
+	return TC_ACT_SHOT;
+}
+SEC("clone_redirect_recv")
+int _clone_redirect_recv(struct __sk_buff *skb)
+{
+	bpf_clone_redirect(skb, skb->ifindex + 1, 1);
+	return TC_ACT_SHOT;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_basertt_kern.c b/samples/bpf/tcp_basertt_kern.c
new file mode 100644
index 000000000..822b0742b
--- /dev/null
+++ b/samples/bpf/tcp_basertt_kern.c
@@ -0,0 +1,71 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set base_rtt to 80us when host is running TCP-NV and
+ * both hosts are in the same datacenter (as determined by IPv6 prefix).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_basertt(struct bpf_sock_ops *skops)
+{
+	char cong[20];
+	char nv[] = "nv";
+	int rv = 0, n;
+	int op;
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check if both hosts are in the same datacenter. For this
+	 * example they are if the 1st 5.5 bytes in the IPv6 address
+	 * are the same.
+	 */
+	if (skops->family == AF_INET6 &&
+	    skops->local_ip6[0] == skops->remote_ip6[0] &&
+	    (bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) ==
+	    (bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000)) {
+		switch (op) {
+		case BPF_SOCK_OPS_BASE_RTT:
+			n = bpf_getsockopt(skops, SOL_TCP, TCP_CONGESTION,
+					   cong, sizeof(cong));
+			if (!n && !__builtin_memcmp(cong, nv, sizeof(nv))) {
+				/* Set base_rtt to 80us */
+				rv = 80;
+			} else if (n) {
+				rv = n;
+			} else {
+				rv = -1;
+			}
+			break;
+		default:
+			rv = -1;
+		}
+	} else {
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_bpf.readme b/samples/bpf/tcp_bpf.readme
new file mode 100644
index 000000000..78e247f62
--- /dev/null
+++ b/samples/bpf/tcp_bpf.readme
@@ -0,0 +1,28 @@
+This file describes how to run the tcp_*_kern.o tcp_bpf (or socket_ops)
+programs. These programs attach to a cgroupv2. The following commands create
+a cgroupv2 and attach a bash shell to the group.
+
+  mkdir -p /tmp/cgroupv2
+  mount -t cgroup2 none /tmp/cgroupv2
+  mkdir -p /tmp/cgroupv2/foo
+  bash
+  echo $$ >> /tmp/cgroupv2/foo/cgroup.procs
+
+Anything that runs under this shell belongs to the foo cgroupv2. To load
+(attach) one of the tcp_*_kern.o programs:
+
+  bpftool prog load tcp_basertt_kern.o /sys/fs/bpf/tcp_prog
+  bpftool cgroup attach /tmp/cgroupv2/foo sock_ops pinned /sys/fs/bpf/tcp_prog
+  bpftool prog tracelog
+
+"bpftool prog tracelog" will continue to run printing the BPF log buffer.
+The tcp_*_kern.o programs use special print functions to print logging
+information (if enabled by the ifdef).
+
+If using netperf/netserver to create traffic, you need to run them under the
+cgroupv2 to which the BPF programs are attached (i.e. under bash shell
+attached to the cgroupv2).
+
+To remove (unattach) a socket_ops BPF program from a cgroupv2:
+
+  bpftool cgroup detach /tmp/cgroupv2/foo sock_ops pinned /sys/fs/bpf/tcp_prog
diff --git a/samples/bpf/tcp_bufs_kern.c b/samples/bpf/tcp_bufs_kern.c
new file mode 100644
index 000000000..6a80d0895
--- /dev/null
+++ b/samples/bpf/tcp_bufs_kern.c
@@ -0,0 +1,81 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set initial receive window to 40 packets and send
+ * and receive buffers to 1.5MB. This would usually be done after
+ * doing appropriate checks that indicate the hosts are far enough
+ * away (i.e. large RTT).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_bufs(struct bpf_sock_ops *skops)
+{
+	int bufsize = 1500000;
+	int rwnd_init = 40;
+	int rv = 0;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 &&
+	    skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+
+	/* Usually there would be a check to insure the hosts are far
+	 * from each other so it makes sense to increase buffer sizes
+	 */
+	switch (op) {
+	case BPF_SOCK_OPS_RWND_INIT:
+		rv = rwnd_init;
+		break;
+	case BPF_SOCK_OPS_TCP_CONNECT_CB:
+		/* Set sndbuf and rcvbuf of active connections */
+		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
+				    sizeof(bufsize));
+		rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+				     &bufsize, sizeof(bufsize));
+		break;
+	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+		/* Nothing to do */
+		break;
+	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+		/* Set sndbuf and rcvbuf of passive connections */
+		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
+				    sizeof(bufsize));
+		rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+				     &bufsize, sizeof(bufsize));
+		break;
+	default:
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_clamp_kern.c b/samples/bpf/tcp_clamp_kern.c
new file mode 100644
index 000000000..e88bd9ab0
--- /dev/null
+++ b/samples/bpf/tcp_clamp_kern.c
@@ -0,0 +1,97 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * Sample BPF program to set send and receive buffers to 150KB, sndcwnd clamp
+ * to 100 packets and SYN and SYN_ACK RTOs to 10ms when both hosts are within
+ * the same datacenter. For his example, we assume they are within the same
+ * datacenter when the first 5.5 bytes of their IPv6 addresses are the same.
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_clamp(struct bpf_sock_ops *skops)
+{
+	int bufsize = 150000;
+	int to_init = 10;
+	int clamp = 100;
+	int rv = 0;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 && skops->local_port != 55601) {
+		skops->reply = -1;
+		return 0;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check that both hosts are within same datacenter. For this example
+	 * it is the case when the first 5.5 bytes of their IPv6 addresses are
+	 * the same.
+	 */
+	if (skops->family == AF_INET6 &&
+	    skops->local_ip6[0] == skops->remote_ip6[0] &&
+	    (bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) ==
+	    (bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000)) {
+		switch (op) {
+		case BPF_SOCK_OPS_TIMEOUT_INIT:
+			rv = to_init;
+			break;
+		case BPF_SOCK_OPS_TCP_CONNECT_CB:
+			/* Set sndbuf and rcvbuf of active connections */
+			rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF,
+					    &bufsize, sizeof(bufsize));
+			rv += bpf_setsockopt(skops, SOL_SOCKET,
+					     SO_RCVBUF, &bufsize,
+					     sizeof(bufsize));
+			break;
+		case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+			rv = bpf_setsockopt(skops, SOL_TCP,
+					    TCP_BPF_SNDCWND_CLAMP,
+					    &clamp, sizeof(clamp));
+			break;
+		case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+			/* Set sndbuf and rcvbuf of passive connections */
+			rv = bpf_setsockopt(skops, SOL_TCP,
+					    TCP_BPF_SNDCWND_CLAMP,
+					    &clamp, sizeof(clamp));
+			rv += bpf_setsockopt(skops, SOL_SOCKET,
+					     SO_SNDBUF, &bufsize,
+					     sizeof(bufsize));
+			rv += bpf_setsockopt(skops, SOL_SOCKET,
+					     SO_RCVBUF, &bufsize,
+					     sizeof(bufsize));
+			break;
+		default:
+			rv = -1;
+		}
+	} else {
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_cong_kern.c b/samples/bpf/tcp_cong_kern.c
new file mode 100644
index 000000000..339415eac
--- /dev/null
+++ b/samples/bpf/tcp_cong_kern.c
@@ -0,0 +1,78 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set congestion control to dctcp when both hosts are
+ * in the same datacenter (as determined by IPv6 prefix).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_cong(struct bpf_sock_ops *skops)
+{
+	char cong[] = "dctcp";
+	int rv = 0;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 &&
+	    skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check if both hosts are in the same datacenter. For this
+	 * example they are if the 1st 5.5 bytes in the IPv6 address
+	 * are the same.
+	 */
+	if (skops->family == AF_INET6 &&
+	    skops->local_ip6[0] == skops->remote_ip6[0] &&
+	    (bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) ==
+	    (bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000)) {
+		switch (op) {
+		case BPF_SOCK_OPS_NEEDS_ECN:
+			rv = 1;
+			break;
+		case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+			rv = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION,
+					    cong, sizeof(cong));
+			break;
+		case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+			rv = bpf_setsockopt(skops, SOL_TCP, TCP_CONGESTION,
+					    cong, sizeof(cong));
+			break;
+		default:
+			rv = -1;
+		}
+	} else {
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_dumpstats_kern.c b/samples/bpf/tcp_dumpstats_kern.c
new file mode 100644
index 000000000..e80d3afd2
--- /dev/null
+++ b/samples/bpf/tcp_dumpstats_kern.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Refer to samples/bpf/tcp_bpf.readme for the instructions on
+ * how to run this sample program.
+ */
+#include <linux/bpf.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define INTERVAL			1000000000ULL
+
+int _version SEC("version") = 1;
+char _license[] SEC("license") = "GPL";
+
+struct {
+	__u32 type;
+	__u32 map_flags;
+	int *key;
+	__u64 *value;
+} bpf_next_dump SEC(".maps") = {
+	.type = BPF_MAP_TYPE_SK_STORAGE,
+	.map_flags = BPF_F_NO_PREALLOC,
+};
+
+SEC("sockops")
+int _sockops(struct bpf_sock_ops *ctx)
+{
+	struct bpf_tcp_sock *tcp_sk;
+	struct bpf_sock *sk;
+	__u64 *next_dump;
+	__u64 now;
+
+	switch (ctx->op) {
+	case BPF_SOCK_OPS_TCP_CONNECT_CB:
+		bpf_sock_ops_cb_flags_set(ctx, BPF_SOCK_OPS_RTT_CB_FLAG);
+		return 1;
+	case BPF_SOCK_OPS_RTT_CB:
+		break;
+	default:
+		return 1;
+	}
+
+	sk = ctx->sk;
+	if (!sk)
+		return 1;
+
+	next_dump = bpf_sk_storage_get(&bpf_next_dump, sk, 0,
+				       BPF_SK_STORAGE_GET_F_CREATE);
+	if (!next_dump)
+		return 1;
+
+	now = bpf_ktime_get_ns();
+	if (now < *next_dump)
+		return 1;
+
+	tcp_sk = bpf_tcp_sock(sk);
+	if (!tcp_sk)
+		return 1;
+
+	*next_dump = now + INTERVAL;
+
+	bpf_printk("dsack_dups=%u delivered=%u\n",
+		   tcp_sk->dsack_dups, tcp_sk->delivered);
+	bpf_printk("delivered_ce=%u icsk_retransmits=%u\n",
+		   tcp_sk->delivered_ce, tcp_sk->icsk_retransmits);
+
+	return 1;
+}
diff --git a/samples/bpf/tcp_iw_kern.c b/samples/bpf/tcp_iw_kern.c
new file mode 100644
index 000000000..d14445573
--- /dev/null
+++ b/samples/bpf/tcp_iw_kern.c
@@ -0,0 +1,83 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set initial congestion window and initial receive
+ * window to 40 packets and send and receive buffers to 1.5MB. This
+ * would usually be done after doing appropriate checks that indicate
+ * the hosts are far enough away (i.e. large RTT).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_iw(struct bpf_sock_ops *skops)
+{
+	int bufsize = 1500000;
+	int rwnd_init = 40;
+	int iw = 40;
+	int rv = 0;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 &&
+	    skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Usually there would be a check to insure the hosts are far
+	 * from each other so it makes sense to increase buffer sizes
+	 */
+	switch (op) {
+	case BPF_SOCK_OPS_RWND_INIT:
+		rv = rwnd_init;
+		break;
+	case BPF_SOCK_OPS_TCP_CONNECT_CB:
+		/* Set sndbuf and rcvbuf of active connections */
+		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
+				    sizeof(bufsize));
+		rv += bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+				     &bufsize, sizeof(bufsize));
+		break;
+	case BPF_SOCK_OPS_ACTIVE_ESTABLISHED_CB:
+		rv = bpf_setsockopt(skops, SOL_TCP, TCP_BPF_IW, &iw,
+				    sizeof(iw));
+		break;
+	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+		/* Set sndbuf and rcvbuf of passive connections */
+		rv = bpf_setsockopt(skops, SOL_SOCKET, SO_SNDBUF, &bufsize,
+				    sizeof(bufsize));
+		rv +=  bpf_setsockopt(skops, SOL_SOCKET, SO_RCVBUF,
+				      &bufsize, sizeof(bufsize));
+		break;
+	default:
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_rwnd_kern.c b/samples/bpf/tcp_rwnd_kern.c
new file mode 100644
index 000000000..223d9c23b
--- /dev/null
+++ b/samples/bpf/tcp_rwnd_kern.c
@@ -0,0 +1,64 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set initial receive window to 40 packets when using IPv6
+ * and the first 5.5 bytes of the IPv6 addresses are not the same (in this
+ * example that means both hosts are not the same datacenter).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_rwnd(struct bpf_sock_ops *skops)
+{
+	int rv = -1;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) !=
+	    55601 && skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check for RWND_INIT operation and IPv6 addresses */
+	if (op == BPF_SOCK_OPS_RWND_INIT &&
+		skops->family == AF_INET6) {
+
+		/* If the first 5.5 bytes of the IPv6 address are not the same
+		 * then both hosts are not in the same datacenter
+		 * so use a larger initial advertized window (40 packets)
+		 */
+		if (skops->local_ip6[0] != skops->remote_ip6[0] ||
+		    (bpf_ntohl(skops->local_ip6[1]) & 0xfffff000) !=
+		    (bpf_ntohl(skops->remote_ip6[1]) & 0xfffff000))
+			rv = 40;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_synrto_kern.c b/samples/bpf/tcp_synrto_kern.c
new file mode 100644
index 000000000..d58004eef
--- /dev/null
+++ b/samples/bpf/tcp_synrto_kern.c
@@ -0,0 +1,64 @@
+/* Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * BPF program to set SYN and SYN-ACK RTOs to 10ms when using IPv6 addresses
+ * and the first 5.5 bytes of the IPv6 addresses are the same (in this example
+ * that means both hosts are in the same datacenter).
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_synrto(struct bpf_sock_ops *skops)
+{
+	int rv = -1;
+	int op;
+
+	/* For testing purposes, only execute rest of BPF program
+	 * if neither port numberis 55601
+	 */
+	if (bpf_ntohl(skops->remote_port) != 55601 &&
+	    skops->local_port != 55601) {
+		skops->reply = -1;
+		return 1;
+	}
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+
+	/* Check for TIMEOUT_INIT operation and IPv6 addresses */
+	if (op == BPF_SOCK_OPS_TIMEOUT_INIT &&
+		skops->family == AF_INET6) {
+
+		/* If the first 5.5 bytes of the IPv6 address are the same
+		 * then both hosts are in the same datacenter
+		 * so use an RTO of 10ms
+		 */
+		if (skops->local_ip6[0] == skops->remote_ip6[0] &&
+		    (bpf_ntohl(skops->local_ip6[1]) & 0xfff00000) ==
+		    (bpf_ntohl(skops->remote_ip6[1]) & 0xfff00000))
+			rv = 10;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/tcp_tos_reflect_kern.c b/samples/bpf/tcp_tos_reflect_kern.c
new file mode 100644
index 000000000..953fedc79
--- /dev/null
+++ b/samples/bpf/tcp_tos_reflect_kern.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018 Facebook
+ *
+ * BPF program to automatically reflect TOS option from received syn packet
+ *
+ * Use "bpftool cgroup attach $cg sock_ops $prog" to load this BPF program.
+ */
+
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/tcp.h>
+#include <uapi/linux/if_ether.h>
+#include <uapi/linux/if_packet.h>
+#include <uapi/linux/ip.h>
+#include <uapi/linux/ipv6.h>
+#include <uapi/linux/in.h>
+#include <linux/socket.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+
+#define DEBUG 1
+
+SEC("sockops")
+int bpf_basertt(struct bpf_sock_ops *skops)
+{
+	char header[sizeof(struct ipv6hdr)];
+	struct ipv6hdr *hdr6;
+	struct iphdr *hdr;
+	int hdr_size = 0;
+	int save_syn = 1;
+	int tos = 0;
+	int rv = 0;
+	int op;
+
+	op = (int) skops->op;
+
+#ifdef DEBUG
+	bpf_printk("BPF command: %d\n", op);
+#endif
+	switch (op) {
+	case BPF_SOCK_OPS_TCP_LISTEN_CB:
+		rv = bpf_setsockopt(skops, SOL_TCP, TCP_SAVE_SYN,
+				   &save_syn, sizeof(save_syn));
+		break;
+	case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB:
+		if (skops->family == AF_INET)
+			hdr_size = sizeof(struct iphdr);
+		else
+			hdr_size = sizeof(struct ipv6hdr);
+		rv = bpf_getsockopt(skops, SOL_TCP, TCP_SAVED_SYN,
+				    header, hdr_size);
+		if (!rv) {
+			if (skops->family == AF_INET) {
+				hdr = (struct iphdr *) header;
+				tos = hdr->tos;
+				if (tos != 0)
+					bpf_setsockopt(skops, SOL_IP, IP_TOS,
+						       &tos, sizeof(tos));
+			} else {
+				hdr6 = (struct ipv6hdr *) header;
+				tos = ((hdr6->priority) << 4 |
+				       (hdr6->flow_lbl[0]) >>  4);
+				if (tos)
+					bpf_setsockopt(skops, SOL_IPV6,
+						       IPV6_TCLASS,
+						       &tos, sizeof(tos));
+			}
+			rv = 0;
+		}
+		break;
+	default:
+		rv = -1;
+	}
+#ifdef DEBUG
+	bpf_printk("Returning %d\n", rv);
+#endif
+	skops->reply = rv;
+	return 1;
+}
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_cls_bpf.sh b/samples/bpf/test_cls_bpf.sh
new file mode 100755
index 000000000..aaddd67b3
--- /dev/null
+++ b/samples/bpf/test_cls_bpf.sh
@@ -0,0 +1,38 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+function pktgen {
+    ../pktgen/pktgen_bench_xmit_mode_netif_receive.sh -i $IFC -s 64 \
+        -m 90:e2:ba:ff:ff:ff -d 192.168.0.1 -t 4
+    local dropped=`tc -s qdisc show dev $IFC | tail -3 | awk '/drop/{print $7}'`
+    if [ "$dropped" == "0," ]; then
+        echo "FAIL"
+    else
+        echo "Successfully filtered " $dropped " packets"
+    fi
+}
+
+function test {
+    echo -n "Loading bpf program '$2'... "
+    tc qdisc add dev $IFC clsact
+    tc filter add dev $IFC ingress bpf da obj $1 sec $2
+    local status=$?
+    if [ $status -ne 0 ]; then
+        echo "FAIL"
+    else
+        echo "ok"
+	pktgen
+    fi
+    tc qdisc del dev $IFC clsact
+}
+
+IFC=test_veth
+
+ip link add name $IFC type veth peer name pair_$IFC
+ip link set $IFC up
+ip link set pair_$IFC up
+
+test ./parse_simple.o simple
+test ./parse_varlen.o varlen
+test ./parse_ldabs.o ldabs
+ip link del dev $IFC
diff --git a/samples/bpf/test_lru_dist.c b/samples/bpf/test_lru_dist.c
new file mode 100644
index 000000000..1c161276d
--- /dev/null
+++ b/samples/bpf/test_lru_dist.c
@@ -0,0 +1,534 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2016 Facebook
+ */
+#define _GNU_SOURCE
+#include <linux/types.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <linux/bpf.h>
+#include <errno.h>
+#include <string.h>
+#include <assert.h>
+#include <sched.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include <bpf/bpf.h>
+#include "bpf_util.h"
+
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#ifndef offsetof
+# define offsetof(TYPE, MEMBER)	((size_t)&((TYPE *)0)->MEMBER)
+#endif
+#define container_of(ptr, type, member) ({			\
+	const typeof( ((type *)0)->member ) *__mptr = (ptr);	\
+	(type *)( (char *)__mptr - offsetof(type,member) );})
+
+static int nr_cpus;
+static unsigned long long *dist_keys;
+static unsigned int dist_key_counts;
+
+struct list_head {
+	struct list_head *next, *prev;
+};
+
+static inline void INIT_LIST_HEAD(struct list_head *list)
+{
+	list->next = list;
+	list->prev = list;
+}
+
+static inline void __list_add(struct list_head *new,
+			      struct list_head *prev,
+			      struct list_head *next)
+{
+	next->prev = new;
+	new->next = next;
+	new->prev = prev;
+	prev->next = new;
+}
+
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+	__list_add(new, head, head->next);
+}
+
+static inline void __list_del(struct list_head *prev, struct list_head *next)
+{
+	next->prev = prev;
+	prev->next = next;
+}
+
+static inline void __list_del_entry(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+}
+
+static inline void list_move(struct list_head *list, struct list_head *head)
+{
+	__list_del_entry(list);
+	list_add(list, head);
+}
+
+#define list_entry(ptr, type, member) \
+	container_of(ptr, type, member)
+
+#define list_last_entry(ptr, type, member) \
+	list_entry((ptr)->prev, type, member)
+
+struct pfect_lru_node {
+	struct list_head list;
+	unsigned long long key;
+};
+
+struct pfect_lru {
+	struct list_head list;
+	struct pfect_lru_node *free_nodes;
+	unsigned int cur_size;
+	unsigned int lru_size;
+	unsigned int nr_unique;
+	unsigned int nr_misses;
+	unsigned int total;
+	int map_fd;
+};
+
+static void pfect_lru_init(struct pfect_lru *lru, unsigned int lru_size,
+			   unsigned int nr_possible_elems)
+{
+	lru->map_fd = bpf_map_create(BPF_MAP_TYPE_HASH, NULL,
+				     sizeof(unsigned long long),
+				     sizeof(struct pfect_lru_node *),
+				     nr_possible_elems, NULL);
+	assert(lru->map_fd != -1);
+
+	lru->free_nodes = malloc(lru_size * sizeof(struct pfect_lru_node));
+	assert(lru->free_nodes);
+
+	INIT_LIST_HEAD(&lru->list);
+	lru->cur_size = 0;
+	lru->lru_size = lru_size;
+	lru->nr_unique = lru->nr_misses = lru->total = 0;
+}
+
+static void pfect_lru_destroy(struct pfect_lru *lru)
+{
+	close(lru->map_fd);
+	free(lru->free_nodes);
+}
+
+static int pfect_lru_lookup_or_insert(struct pfect_lru *lru,
+				      unsigned long long key)
+{
+	struct pfect_lru_node *node = NULL;
+	int seen = 0;
+
+	lru->total++;
+	if (!bpf_map_lookup_elem(lru->map_fd, &key, &node)) {
+		if (node) {
+			list_move(&node->list, &lru->list);
+			return 1;
+		}
+		seen = 1;
+	}
+
+	if (lru->cur_size < lru->lru_size) {
+		node =  &lru->free_nodes[lru->cur_size++];
+		INIT_LIST_HEAD(&node->list);
+	} else {
+		struct pfect_lru_node *null_node = NULL;
+
+		node = list_last_entry(&lru->list,
+				       struct pfect_lru_node,
+				       list);
+		bpf_map_update_elem(lru->map_fd, &node->key, &null_node, BPF_EXIST);
+	}
+
+	node->key = key;
+	list_move(&node->list, &lru->list);
+
+	lru->nr_misses++;
+	if (seen) {
+		assert(!bpf_map_update_elem(lru->map_fd, &key, &node, BPF_EXIST));
+	} else {
+		lru->nr_unique++;
+		assert(!bpf_map_update_elem(lru->map_fd, &key, &node, BPF_NOEXIST));
+	}
+
+	return seen;
+}
+
+static unsigned int read_keys(const char *dist_file,
+			      unsigned long long **keys)
+{
+	struct stat fst;
+	unsigned long long *retkeys;
+	unsigned int counts = 0;
+	int dist_fd;
+	char *b, *l;
+	int i;
+
+	dist_fd = open(dist_file, 0);
+	assert(dist_fd != -1);
+
+	assert(fstat(dist_fd, &fst) == 0);
+	b = malloc(fst.st_size);
+	assert(b);
+
+	assert(read(dist_fd, b, fst.st_size) == fst.st_size);
+	close(dist_fd);
+	for (i = 0; i < fst.st_size; i++) {
+		if (b[i] == '\n')
+			counts++;
+	}
+	counts++; /* in case the last line has no \n */
+
+	retkeys = malloc(counts * sizeof(unsigned long long));
+	assert(retkeys);
+
+	counts = 0;
+	for (l = strtok(b, "\n"); l; l = strtok(NULL, "\n"))
+		retkeys[counts++] = strtoull(l, NULL, 10);
+	free(b);
+
+	*keys = retkeys;
+
+	return counts;
+}
+
+static int create_map(int map_type, int map_flags, unsigned int size)
+{
+	LIBBPF_OPTS(bpf_map_create_opts, opts,
+		.map_flags = map_flags,
+	);
+	int map_fd;
+
+	map_fd = bpf_map_create(map_type, NULL, sizeof(unsigned long long),
+				sizeof(unsigned long long), size, &opts);
+
+	if (map_fd == -1)
+		perror("bpf_create_map");
+
+	return map_fd;
+}
+
+static int sched_next_online(int pid, int next_to_try)
+{
+	cpu_set_t cpuset;
+
+	if (next_to_try == nr_cpus)
+		return -1;
+
+	while (next_to_try < nr_cpus) {
+		CPU_ZERO(&cpuset);
+		CPU_SET(next_to_try++, &cpuset);
+		if (!sched_setaffinity(pid, sizeof(cpuset), &cpuset))
+			break;
+	}
+
+	return next_to_try;
+}
+
+static void run_parallel(unsigned int tasks, void (*fn)(int i, void *data),
+			 void *data)
+{
+	int next_sched_cpu = 0;
+	pid_t pid[tasks];
+	int i;
+
+	for (i = 0; i < tasks; i++) {
+		pid[i] = fork();
+		if (pid[i] == 0) {
+			next_sched_cpu = sched_next_online(0, next_sched_cpu);
+			fn(i, data);
+			exit(0);
+		} else if (pid[i] == -1) {
+			printf("couldn't spawn #%d process\n", i);
+			exit(1);
+		}
+		/* It is mostly redundant and just allow the parent
+		 * process to update next_shced_cpu for the next child
+		 * process
+		 */
+		next_sched_cpu = sched_next_online(pid[i], next_sched_cpu);
+	}
+	for (i = 0; i < tasks; i++) {
+		int status;
+
+		assert(waitpid(pid[i], &status, 0) == pid[i]);
+		assert(status == 0);
+	}
+}
+
+static void do_test_lru_dist(int task, void *data)
+{
+	unsigned int nr_misses = 0;
+	struct pfect_lru pfect_lru;
+	unsigned long long key, value = 1234;
+	unsigned int i;
+
+	unsigned int lru_map_fd = ((unsigned int *)data)[0];
+	unsigned int lru_size = ((unsigned int *)data)[1];
+	unsigned long long key_offset = task * dist_key_counts;
+
+	pfect_lru_init(&pfect_lru, lru_size, dist_key_counts);
+
+	for (i = 0; i < dist_key_counts; i++) {
+		key = dist_keys[i] + key_offset;
+
+		pfect_lru_lookup_or_insert(&pfect_lru, key);
+
+		if (!bpf_map_lookup_elem(lru_map_fd, &key, &value))
+			continue;
+
+		if (bpf_map_update_elem(lru_map_fd, &key, &value, BPF_NOEXIST)) {
+			printf("bpf_map_update_elem(lru_map_fd, %llu): errno:%d\n",
+			       key, errno);
+			assert(0);
+		}
+
+		nr_misses++;
+	}
+
+	printf("    task:%d BPF LRU: nr_unique:%u(/%u) nr_misses:%u(/%u)\n",
+	       task, pfect_lru.nr_unique, dist_key_counts, nr_misses,
+	       dist_key_counts);
+	printf("    task:%d Perfect LRU: nr_unique:%u(/%u) nr_misses:%u(/%u)\n",
+	       task, pfect_lru.nr_unique, pfect_lru.total,
+	       pfect_lru.nr_misses, pfect_lru.total);
+
+	pfect_lru_destroy(&pfect_lru);
+	close(lru_map_fd);
+}
+
+static void test_parallel_lru_dist(int map_type, int map_flags,
+				   int nr_tasks, unsigned int lru_size)
+{
+	int child_data[2];
+	int lru_map_fd;
+
+	printf("%s (map_type:%d map_flags:0x%X):\n", __func__, map_type,
+	       map_flags);
+
+	if (map_flags & BPF_F_NO_COMMON_LRU)
+		lru_map_fd = create_map(map_type, map_flags,
+					nr_cpus * lru_size);
+	else
+		lru_map_fd = create_map(map_type, map_flags,
+					nr_tasks * lru_size);
+	assert(lru_map_fd != -1);
+
+	child_data[0] = lru_map_fd;
+	child_data[1] = lru_size;
+
+	run_parallel(nr_tasks, do_test_lru_dist, child_data);
+
+	close(lru_map_fd);
+}
+
+static void test_lru_loss0(int map_type, int map_flags)
+{
+	unsigned long long key, value[nr_cpus];
+	unsigned int old_unused_losses = 0;
+	unsigned int new_unused_losses = 0;
+	unsigned int used_losses = 0;
+	int map_fd;
+
+	printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
+	       map_flags);
+
+	assert(sched_next_online(0, 0) != -1);
+
+	if (map_flags & BPF_F_NO_COMMON_LRU)
+		map_fd = create_map(map_type, map_flags, 900 * nr_cpus);
+	else
+		map_fd = create_map(map_type, map_flags, 900);
+
+	assert(map_fd != -1);
+
+	value[0] = 1234;
+
+	for (key = 1; key <= 1000; key++) {
+		int start_key, end_key;
+
+		assert(bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST) == 0);
+
+		start_key = 101;
+		end_key = min(key, 900);
+
+		while (start_key <= end_key) {
+			bpf_map_lookup_elem(map_fd, &start_key, value);
+			start_key++;
+		}
+	}
+
+	for (key = 1; key <= 1000; key++) {
+		if (bpf_map_lookup_elem(map_fd, &key, value)) {
+			if (key <= 100)
+				old_unused_losses++;
+			else if (key <= 900)
+				used_losses++;
+			else
+				new_unused_losses++;
+		}
+	}
+
+	close(map_fd);
+
+	printf("older-elem-losses:%d(/100) active-elem-losses:%d(/800) "
+	       "newer-elem-losses:%d(/100)\n",
+	       old_unused_losses, used_losses, new_unused_losses);
+}
+
+static void test_lru_loss1(int map_type, int map_flags)
+{
+	unsigned long long key, value[nr_cpus];
+	int map_fd;
+	unsigned int nr_losses = 0;
+
+	printf("%s (map_type:%d map_flags:0x%X): ", __func__, map_type,
+	       map_flags);
+
+	assert(sched_next_online(0, 0) != -1);
+
+	if (map_flags & BPF_F_NO_COMMON_LRU)
+		map_fd = create_map(map_type, map_flags, 1000 * nr_cpus);
+	else
+		map_fd = create_map(map_type, map_flags, 1000);
+
+	assert(map_fd != -1);
+
+	value[0] = 1234;
+
+	for (key = 1; key <= 1000; key++)
+		assert(!bpf_map_update_elem(map_fd, &key, value, BPF_NOEXIST));
+
+	for (key = 1; key <= 1000; key++) {
+		if (bpf_map_lookup_elem(map_fd, &key, value))
+			nr_losses++;
+	}
+
+	close(map_fd);
+
+	printf("nr_losses:%d(/1000)\n", nr_losses);
+}
+
+static void do_test_parallel_lru_loss(int task, void *data)
+{
+	const unsigned int nr_stable_elems = 1000;
+	const unsigned int nr_repeats = 100000;
+
+	int map_fd = *(int *)data;
+	unsigned long long stable_base;
+	unsigned long long key, value[nr_cpus];
+	unsigned long long next_ins_key;
+	unsigned int nr_losses = 0;
+	unsigned int i;
+
+	stable_base = task * nr_repeats * 2 + 1;
+	next_ins_key = stable_base;
+	value[0] = 1234;
+	for (i = 0; i < nr_stable_elems; i++) {
+		assert(bpf_map_update_elem(map_fd, &next_ins_key, value,
+				       BPF_NOEXIST) == 0);
+		next_ins_key++;
+	}
+
+	for (i = 0; i < nr_repeats; i++) {
+		int rn;
+
+		rn = rand();
+
+		if (rn % 10) {
+			key = rn % nr_stable_elems + stable_base;
+			bpf_map_lookup_elem(map_fd, &key, value);
+		} else {
+			bpf_map_update_elem(map_fd, &next_ins_key, value,
+					BPF_NOEXIST);
+			next_ins_key++;
+		}
+	}
+
+	key = stable_base;
+	for (i = 0; i < nr_stable_elems; i++) {
+		if (bpf_map_lookup_elem(map_fd, &key, value))
+			nr_losses++;
+		key++;
+	}
+
+	printf("    task:%d nr_losses:%u\n", task, nr_losses);
+}
+
+static void test_parallel_lru_loss(int map_type, int map_flags, int nr_tasks)
+{
+	int map_fd;
+
+	printf("%s (map_type:%d map_flags:0x%X):\n", __func__, map_type,
+	       map_flags);
+
+	/* Give 20% more than the active working set */
+	if (map_flags & BPF_F_NO_COMMON_LRU)
+		map_fd = create_map(map_type, map_flags,
+				    nr_cpus * (1000 + 200));
+	else
+		map_fd = create_map(map_type, map_flags,
+				    nr_tasks * (1000 + 200));
+
+	assert(map_fd != -1);
+
+	run_parallel(nr_tasks, do_test_parallel_lru_loss, &map_fd);
+
+	close(map_fd);
+}
+
+int main(int argc, char **argv)
+{
+	int map_flags[] = {0, BPF_F_NO_COMMON_LRU};
+	const char *dist_file;
+	int nr_tasks = 1;
+	int lru_size;
+	int f;
+
+	if (argc < 4) {
+		printf("Usage: %s <dist-file> <lru-size> <nr-tasks>\n",
+		       argv[0]);
+		return -1;
+	}
+
+	dist_file = argv[1];
+	lru_size = atoi(argv[2]);
+	nr_tasks = atoi(argv[3]);
+
+	setbuf(stdout, NULL);
+
+	srand(time(NULL));
+
+	nr_cpus = bpf_num_possible_cpus();
+	assert(nr_cpus != -1);
+	printf("nr_cpus:%d\n\n", nr_cpus);
+
+	nr_tasks = min(nr_tasks, nr_cpus);
+
+	dist_key_counts = read_keys(dist_file, &dist_keys);
+	if (!dist_key_counts) {
+		printf("%s has no key\n", dist_file);
+		return -1;
+	}
+
+	for (f = 0; f < ARRAY_SIZE(map_flags); f++) {
+		test_lru_loss0(BPF_MAP_TYPE_LRU_HASH, map_flags[f]);
+		test_lru_loss1(BPF_MAP_TYPE_LRU_HASH, map_flags[f]);
+		test_parallel_lru_loss(BPF_MAP_TYPE_LRU_HASH, map_flags[f],
+				       nr_tasks);
+		test_parallel_lru_dist(BPF_MAP_TYPE_LRU_HASH, map_flags[f],
+				       nr_tasks, lru_size);
+		printf("\n");
+	}
+
+	free(dist_keys);
+
+	return 0;
+}
diff --git a/samples/bpf/test_lwt_bpf.c b/samples/bpf/test_lwt_bpf.c
new file mode 100644
index 000000000..9a13dbb81
--- /dev/null
+++ b/samples/bpf/test_lwt_bpf.c
@@ -0,0 +1,245 @@
+/* Copyright (c) 2016 Thomas Graf <tgraf@tgraf.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include "vmlinux.h"
+#include "net_shared.h"
+#include <bpf/bpf_helpers.h>
+#include <string.h>
+
+# define printk(fmt, ...)						\
+		({							\
+			char ____fmt[] = fmt;				\
+			bpf_trace_printk(____fmt, sizeof(____fmt),	\
+				     ##__VA_ARGS__);			\
+		})
+
+#define CB_MAGIC 1234
+
+/* Test: Pass all packets through */
+SEC("nop")
+int do_nop(struct __sk_buff *skb)
+{
+	return BPF_OK;
+}
+
+/* Test: Verify context information can be accessed */
+SEC("test_ctx")
+int do_test_ctx(struct __sk_buff *skb)
+{
+	skb->cb[0] = CB_MAGIC;
+	printk("len %d hash %d protocol %d", skb->len, skb->hash,
+	       skb->protocol);
+	printk("cb %d ingress_ifindex %d ifindex %d", skb->cb[0],
+	       skb->ingress_ifindex, skb->ifindex);
+
+	return BPF_OK;
+}
+
+/* Test: Ensure skb->cb[] buffer is cleared */
+SEC("test_cb")
+int do_test_cb(struct __sk_buff *skb)
+{
+	printk("cb0: %x cb1: %x cb2: %x", skb->cb[0], skb->cb[1],
+	       skb->cb[2]);
+	printk("cb3: %x cb4: %x", skb->cb[3], skb->cb[4]);
+
+	return BPF_OK;
+}
+
+/* Test: Verify skb data can be read */
+SEC("test_data")
+int do_test_data(struct __sk_buff *skb)
+{
+	void *data = (void *)(long)skb->data;
+	void *data_end = (void *)(long)skb->data_end;
+	struct iphdr *iph = data;
+
+	if (data + sizeof(*iph) > data_end) {
+		printk("packet truncated");
+		return BPF_DROP;
+	}
+
+	printk("src: %x dst: %x", iph->saddr, iph->daddr);
+
+	return BPF_OK;
+}
+
+#define IP_CSUM_OFF offsetof(struct iphdr, check)
+#define IP_DST_OFF offsetof(struct iphdr, daddr)
+#define IP_SRC_OFF offsetof(struct iphdr, saddr)
+#define IP_PROTO_OFF offsetof(struct iphdr, protocol)
+#define TCP_CSUM_OFF offsetof(struct tcphdr, check)
+#define UDP_CSUM_OFF offsetof(struct udphdr, check)
+#define IS_PSEUDO 0x10
+
+static inline int rewrite(struct __sk_buff *skb, uint32_t old_ip,
+			  uint32_t new_ip, int rw_daddr)
+{
+	int ret, off = 0, flags = IS_PSEUDO;
+	uint8_t proto;
+
+	ret = bpf_skb_load_bytes(skb, IP_PROTO_OFF, &proto, 1);
+	if (ret < 0) {
+		printk("bpf_l4_csum_replace failed: %d", ret);
+		return BPF_DROP;
+	}
+
+	switch (proto) {
+	case IPPROTO_TCP:
+		off = TCP_CSUM_OFF;
+		break;
+
+	case IPPROTO_UDP:
+		off = UDP_CSUM_OFF;
+		flags |= BPF_F_MARK_MANGLED_0;
+		break;
+
+	case IPPROTO_ICMPV6:
+		off = offsetof(struct icmp6hdr, icmp6_cksum);
+		break;
+	}
+
+	if (off) {
+		ret = bpf_l4_csum_replace(skb, off, old_ip, new_ip,
+					  flags | sizeof(new_ip));
+		if (ret < 0) {
+			printk("bpf_l4_csum_replace failed: %d");
+			return BPF_DROP;
+		}
+	}
+
+	ret = bpf_l3_csum_replace(skb, IP_CSUM_OFF, old_ip, new_ip, sizeof(new_ip));
+	if (ret < 0) {
+		printk("bpf_l3_csum_replace failed: %d", ret);
+		return BPF_DROP;
+	}
+
+	if (rw_daddr)
+		ret = bpf_skb_store_bytes(skb, IP_DST_OFF, &new_ip, sizeof(new_ip), 0);
+	else
+		ret = bpf_skb_store_bytes(skb, IP_SRC_OFF, &new_ip, sizeof(new_ip), 0);
+
+	if (ret < 0) {
+		printk("bpf_skb_store_bytes() failed: %d", ret);
+		return BPF_DROP;
+	}
+
+	return BPF_OK;
+}
+
+/* Test: Verify skb data can be modified */
+SEC("test_rewrite")
+int do_test_rewrite(struct __sk_buff *skb)
+{
+	uint32_t old_ip, new_ip = 0x3fea8c0;
+	int ret;
+
+	ret = bpf_skb_load_bytes(skb, IP_DST_OFF, &old_ip, 4);
+	if (ret < 0) {
+		printk("bpf_skb_load_bytes failed: %d", ret);
+		return BPF_DROP;
+	}
+
+	if (old_ip == 0x2fea8c0) {
+		printk("out: rewriting from %x to %x", old_ip, new_ip);
+		return rewrite(skb, old_ip, new_ip, 1);
+	}
+
+	return BPF_OK;
+}
+
+static inline int __do_push_ll_and_redirect(struct __sk_buff *skb)
+{
+	uint64_t smac = SRC_MAC, dmac = DST_MAC;
+	int ret, ifindex = DST_IFINDEX;
+	struct ethhdr ehdr;
+
+	ret = bpf_skb_change_head(skb, 14, 0);
+	if (ret < 0) {
+		printk("skb_change_head() failed: %d", ret);
+	}
+
+	ehdr.h_proto = bpf_htons(ETH_P_IP);
+	memcpy(&ehdr.h_source, &smac, 6);
+	memcpy(&ehdr.h_dest, &dmac, 6);
+
+	ret = bpf_skb_store_bytes(skb, 0, &ehdr, sizeof(ehdr), 0);
+	if (ret < 0) {
+		printk("skb_store_bytes() failed: %d", ret);
+		return BPF_DROP;
+	}
+
+	return bpf_redirect(ifindex, 0);
+}
+
+SEC("push_ll_and_redirect_silent")
+int do_push_ll_and_redirect_silent(struct __sk_buff *skb)
+{
+	return __do_push_ll_and_redirect(skb);
+}
+
+SEC("push_ll_and_redirect")
+int do_push_ll_and_redirect(struct __sk_buff *skb)
+{
+	int ret, ifindex = DST_IFINDEX;
+
+	ret = __do_push_ll_and_redirect(skb);
+	if (ret >= 0)
+		printk("redirected to %d", ifindex);
+
+	return ret;
+}
+
+static inline void __fill_garbage(struct __sk_buff *skb)
+{
+	uint64_t f = 0xFFFFFFFFFFFFFFFF;
+
+	bpf_skb_store_bytes(skb, 0, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 8, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 16, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 24, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 32, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 40, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 48, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 56, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 64, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 72, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 80, &f, sizeof(f), 0);
+	bpf_skb_store_bytes(skb, 88, &f, sizeof(f), 0);
+}
+
+SEC("fill_garbage")
+int do_fill_garbage(struct __sk_buff *skb)
+{
+	__fill_garbage(skb);
+	printk("Set initial 96 bytes of header to FF");
+	return BPF_OK;
+}
+
+SEC("fill_garbage_and_redirect")
+int do_fill_garbage_and_redirect(struct __sk_buff *skb)
+{
+	int ifindex = DST_IFINDEX;
+	__fill_garbage(skb);
+	printk("redirected to %d", ifindex);
+	return bpf_redirect(ifindex, 0);
+}
+
+/* Drop all packets */
+SEC("drop_all")
+int do_drop_all(struct __sk_buff *skb)
+{
+	printk("dropping with: %d", BPF_DROP);
+	return BPF_DROP;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/test_lwt_bpf.sh b/samples/bpf/test_lwt_bpf.sh
new file mode 100755
index 000000000..148e2df6c
--- /dev/null
+++ b/samples/bpf/test_lwt_bpf.sh
@@ -0,0 +1,405 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Uncomment to see generated bytecode
+#VERBOSE=verbose
+
+NS1=lwt_ns1
+NS2=lwt_ns2
+VETH0=tst_lwt1a
+VETH1=tst_lwt1b
+VETH2=tst_lwt2a
+VETH3=tst_lwt2b
+IPVETH0="192.168.254.1"
+IPVETH1="192.168.254.2"
+IPVETH1b="192.168.254.3"
+
+IPVETH2="192.168.111.1"
+IPVETH3="192.168.111.2"
+
+IP_LOCAL="192.168.99.1"
+
+PROG_SRC="test_lwt_bpf.c"
+BPF_PROG="test_lwt_bpf.o"
+TRACE_ROOT=/sys/kernel/tracing
+CONTEXT_INFO=$(cat ${TRACE_ROOT}/trace_options | grep context)
+
+function lookup_mac()
+{
+	set +x
+	if [ ! -z "$2" ]; then
+		MAC=$(ip netns exec $2 ip link show $1 | grep ether | awk '{print $2}')
+	else
+		MAC=$(ip link show $1 | grep ether | awk '{print $2}')
+	fi
+	MAC="${MAC//:/}"
+	echo "0x${MAC:10:2}${MAC:8:2}${MAC:6:2}${MAC:4:2}${MAC:2:2}${MAC:0:2}"
+	set -x
+}
+
+function cleanup {
+	set +ex
+	rm $BPF_PROG 2> /dev/null
+	ip link del $VETH0 2> /dev/null
+	ip link del $VETH1 2> /dev/null
+	ip link del $VETH2 2> /dev/null
+	ip link del $VETH3 2> /dev/null
+	ip netns exec $NS1 killall netserver
+	ip netns delete $NS1 2> /dev/null
+	ip netns delete $NS2 2> /dev/null
+	set -ex
+}
+
+function setup_one_veth {
+	ip netns add $1
+	ip link add $2 type veth peer name $3
+	ip link set dev $2 up
+	ip addr add $4/24 dev $2
+	ip link set $3 netns $1
+	ip netns exec $1 ip link set dev $3 up
+	ip netns exec $1 ip addr add $5/24 dev $3
+
+	if [ "$6" ]; then
+		ip netns exec $1 ip addr add $6/32 dev $3
+	fi
+}
+
+function get_trace {
+	set +x
+	cat ${TRACE_ROOT}/trace | grep -v '^#'
+	set -x
+}
+
+function cleanup_routes {
+	ip route del ${IPVETH1}/32 dev $VETH0 2> /dev/null || true
+	ip route del table local local ${IP_LOCAL}/32 dev lo 2> /dev/null || true
+}
+
+function install_test {
+	cleanup_routes
+	cp /dev/null ${TRACE_ROOT}/trace
+
+	OPTS="encap bpf headroom 14 $1 obj $BPF_PROG section $2 $VERBOSE"
+
+	if [ "$1" == "in" ];  then
+		ip route add table local local ${IP_LOCAL}/32 $OPTS dev lo
+	else
+		ip route add ${IPVETH1}/32 $OPTS dev $VETH0
+	fi
+}
+
+function remove_prog {
+	if [ "$1" == "in" ];  then
+		ip route del table local local ${IP_LOCAL}/32 dev lo
+	else
+		ip route del ${IPVETH1}/32 dev $VETH0
+	fi
+}
+
+function filter_trace {
+	# Add newline to allow starting EXPECT= variables on newline
+	NL=$'\n'
+	echo "${NL}$*" | sed -e 's/bpf_trace_printk: //g'
+}
+
+function expect_fail {
+	set +x
+	echo "FAIL:"
+	echo "Expected: $1"
+	echo "Got: $2"
+	set -x
+	exit 1
+}
+
+function match_trace {
+	set +x
+	RET=0
+	TRACE=$1
+	EXPECT=$2
+	GOT="$(filter_trace "$TRACE")"
+
+	[ "$GOT" != "$EXPECT" ] && {
+		expect_fail "$EXPECT" "$GOT"
+		RET=1
+	}
+	set -x
+	return $RET
+}
+
+function test_start {
+	set +x
+	echo "----------------------------------------------------------------"
+	echo "Starting test: $*"
+	echo "----------------------------------------------------------------"
+	set -x
+}
+
+function failure {
+	get_trace
+	echo "FAIL: $*"
+	exit 1
+}
+
+function test_ctx_xmit {
+	test_start "test_ctx on lwt xmit"
+	install_test xmit test_ctx
+	ping -c 3 $IPVETH1 || {
+		failure "test_ctx xmit: packets are dropped"
+	}
+	match_trace "$(get_trace)" "
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex $DST_IFINDEX
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex $DST_IFINDEX
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex $DST_IFINDEX" || exit 1
+	remove_prog xmit
+}
+
+function test_ctx_out {
+	test_start "test_ctx on lwt out"
+	install_test out test_ctx
+	ping -c 3 $IPVETH1 || {
+		failure "test_ctx out: packets are dropped"
+	}
+	match_trace "$(get_trace)" "
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex 0
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex 0
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 0 ifindex 0" || exit 1
+	remove_prog out
+}
+
+function test_ctx_in {
+	test_start "test_ctx on lwt in"
+	install_test in test_ctx
+	ping -c 3 $IP_LOCAL || {
+		failure "test_ctx out: packets are dropped"
+	}
+	# We will both request & reply packets as the packets will
+	# be from $IP_LOCAL => $IP_LOCAL
+	match_trace "$(get_trace)" "
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1
+len 84 hash 0 protocol 8
+cb 1234 ingress_ifindex 1 ifindex 1" || exit 1
+	remove_prog in
+}
+
+function test_data {
+	test_start "test_data on lwt $1"
+	install_test $1 test_data
+	ping -c 3 $IPVETH1 || {
+		failure "test_data ${1}: packets are dropped"
+	}
+	match_trace "$(get_trace)" "
+src: 1fea8c0 dst: 2fea8c0
+src: 1fea8c0 dst: 2fea8c0
+src: 1fea8c0 dst: 2fea8c0" || exit 1
+	remove_prog $1
+}
+
+function test_data_in {
+	test_start "test_data on lwt in"
+	install_test in test_data
+	ping -c 3 $IP_LOCAL || {
+		failure "test_data in: packets are dropped"
+	}
+	# We will both request & reply packets as the packets will
+	# be from $IP_LOCAL => $IP_LOCAL
+	match_trace "$(get_trace)" "
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0
+src: 163a8c0 dst: 163a8c0" || exit 1
+	remove_prog in
+}
+
+function test_cb {
+	test_start "test_cb on lwt $1"
+	install_test $1 test_cb
+	ping -c 3 $IPVETH1 || {
+		failure "test_cb ${1}: packets are dropped"
+	}
+	match_trace "$(get_trace)" "
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0" || exit 1
+	remove_prog $1
+}
+
+function test_cb_in {
+	test_start "test_cb on lwt in"
+	install_test in test_cb
+	ping -c 3 $IP_LOCAL || {
+		failure "test_cb in: packets are dropped"
+	}
+	# We will both request & reply packets as the packets will
+	# be from $IP_LOCAL => $IP_LOCAL
+	match_trace "$(get_trace)" "
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0
+cb0: 0 cb1: 0 cb2: 0
+cb3: 0 cb4: 0" || exit 1
+	remove_prog in
+}
+
+function test_drop_all {
+	test_start "test_drop_all on lwt $1"
+	install_test $1 drop_all
+	ping -c 3 $IPVETH1 && {
+		failure "test_drop_all ${1}: Unexpected success of ping"
+	}
+	match_trace "$(get_trace)" "
+dropping with: 2
+dropping with: 2
+dropping with: 2" || exit 1
+	remove_prog $1
+}
+
+function test_drop_all_in {
+	test_start "test_drop_all on lwt in"
+	install_test in drop_all
+	ping -c 3 $IP_LOCAL && {
+		failure "test_drop_all in: Unexpected success of ping"
+	}
+	match_trace "$(get_trace)" "
+dropping with: 2
+dropping with: 2
+dropping with: 2" || exit 1
+	remove_prog in
+}
+
+function test_push_ll_and_redirect {
+	test_start "test_push_ll_and_redirect on lwt xmit"
+	install_test xmit push_ll_and_redirect
+	ping -c 3 $IPVETH1 || {
+		failure "Redirected packets appear to be dropped"
+	}
+	match_trace "$(get_trace)" "
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX" || exit 1
+	remove_prog xmit
+}
+
+function test_no_l2_and_redirect {
+	test_start "test_no_l2_and_redirect on lwt xmit"
+	install_test xmit fill_garbage_and_redirect
+	ping -c 3 $IPVETH1 && {
+		failure "Unexpected success despite lack of L2 header"
+	}
+	match_trace "$(get_trace)" "
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX
+redirected to $DST_IFINDEX" || exit 1
+	remove_prog xmit
+}
+
+function test_rewrite {
+	test_start "test_rewrite on lwt xmit"
+	install_test xmit test_rewrite
+	ping -c 3 $IPVETH1 || {
+		failure "Rewritten packets appear to be dropped"
+	}
+	match_trace "$(get_trace)" "
+out: rewriting from 2fea8c0 to 3fea8c0
+out: rewriting from 2fea8c0 to 3fea8c0
+out: rewriting from 2fea8c0 to 3fea8c0" || exit 1
+	remove_prog out
+}
+
+function test_fill_garbage {
+	test_start "test_fill_garbage on lwt xmit"
+	install_test xmit fill_garbage
+	ping -c 3 $IPVETH1 && {
+		failure "test_drop_all ${1}: Unexpected success of ping"
+	}
+	match_trace "$(get_trace)" "
+Set initial 96 bytes of header to FF
+Set initial 96 bytes of header to FF
+Set initial 96 bytes of header to FF" || exit 1
+	remove_prog xmit
+}
+
+function test_netperf_nop {
+	test_start "test_netperf_nop on lwt xmit"
+	install_test xmit nop
+	netperf -H $IPVETH1 -t TCP_STREAM || {
+		failure "packets appear to be dropped"
+	}
+	match_trace "$(get_trace)" ""|| exit 1
+	remove_prog xmit
+}
+
+function test_netperf_redirect {
+	test_start "test_netperf_redirect on lwt xmit"
+	install_test xmit push_ll_and_redirect_silent
+	netperf -H $IPVETH1 -t TCP_STREAM || {
+		failure "Rewritten packets appear to be dropped"
+	}
+	match_trace "$(get_trace)" ""|| exit 1
+	remove_prog xmit
+}
+
+cleanup
+setup_one_veth $NS1 $VETH0 $VETH1 $IPVETH0 $IPVETH1 $IPVETH1b
+setup_one_veth $NS2 $VETH2 $VETH3 $IPVETH2 $IPVETH3
+ip netns exec $NS1 netserver
+echo 1 > ${TRACE_ROOT}/tracing_on
+echo nocontext-info > ${TRACE_ROOT}/trace_options
+
+DST_MAC=$(lookup_mac $VETH1 $NS1)
+SRC_MAC=$(lookup_mac $VETH0)
+DST_IFINDEX=$(cat /sys/class/net/$VETH0/ifindex)
+
+CLANG_OPTS="-O2 --target=bpf -I ../include/"
+CLANG_OPTS+=" -DSRC_MAC=$SRC_MAC -DDST_MAC=$DST_MAC -DDST_IFINDEX=$DST_IFINDEX"
+clang $CLANG_OPTS -c $PROG_SRC -o $BPF_PROG
+
+test_ctx_xmit
+test_ctx_out
+test_ctx_in
+test_data "xmit"
+test_data "out"
+test_data_in
+test_cb "xmit"
+test_cb "out"
+test_cb_in
+test_drop_all "xmit"
+test_drop_all "out"
+test_drop_all_in
+test_rewrite
+test_push_ll_and_redirect
+test_no_l2_and_redirect
+test_fill_garbage
+test_netperf_nop
+test_netperf_redirect
+
+cleanup
+echo 0 > ${TRACE_ROOT}/tracing_on
+echo $CONTEXT_INFO > ${TRACE_ROOT}/trace_options
+exit 0
diff --git a/samples/bpf/test_map_in_map.bpf.c b/samples/bpf/test_map_in_map.bpf.c
new file mode 100644
index 000000000..9f030f9c4
--- /dev/null
+++ b/samples/bpf/test_map_in_map.bpf.c
@@ -0,0 +1,172 @@
+/*
+ * Copyright (c) 2017 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#define KBUILD_MODNAME "foo"
+#include "vmlinux.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#define MAX_NR_PORTS 65536
+
+#define EINVAL 22
+#define ENOENT 2
+
+/* map #0 */
+struct inner_a {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, u32);
+	__type(value, int);
+	__uint(max_entries, MAX_NR_PORTS);
+} port_a SEC(".maps");
+
+/* map #1 */
+struct inner_h {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, int);
+	__uint(max_entries, 1);
+} port_h SEC(".maps");
+
+/* map #2 */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, int);
+	__uint(max_entries, 1);
+} reg_result_h SEC(".maps");
+
+/* map #3 */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, u32);
+	__type(value, int);
+	__uint(max_entries, 1);
+} inline_result_h SEC(".maps");
+
+/* map #4 */ /* Test case #0 */
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY_OF_MAPS);
+	__uint(max_entries, MAX_NR_PORTS);
+	__uint(key_size, sizeof(u32));
+	__array(values, struct inner_a); /* use inner_a as inner map */
+} a_of_port_a SEC(".maps");
+
+/* map #5 */ /* Test case #1 */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
+	__uint(max_entries, 1);
+	__uint(key_size, sizeof(u32));
+	__array(values, struct inner_a); /* use inner_a as inner map */
+} h_of_port_a SEC(".maps");
+
+/* map #6 */ /* Test case #2 */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH_OF_MAPS);
+	__uint(max_entries, 1);
+	__uint(key_size, sizeof(u32));
+	__array(values, struct inner_h); /* use inner_h as inner map */
+} h_of_port_h SEC(".maps");
+
+static __always_inline int do_reg_lookup(void *inner_map, u32 port)
+{
+	int *result;
+
+	result = bpf_map_lookup_elem(inner_map, &port);
+	return result ? *result : -ENOENT;
+}
+
+static __always_inline int do_inline_array_lookup(void *inner_map, u32 port)
+{
+	int *result;
+
+	if (inner_map != &port_a)
+		return -EINVAL;
+
+	result = bpf_map_lookup_elem(&port_a, &port);
+	return result ? *result : -ENOENT;
+}
+
+static __always_inline int do_inline_hash_lookup(void *inner_map, u32 port)
+{
+	int *result;
+
+	if (inner_map != &port_h)
+		return -EINVAL;
+
+	result = bpf_map_lookup_elem(&port_h, &port);
+	return result ? *result : -ENOENT;
+}
+
+SEC("ksyscall/connect")
+int BPF_KSYSCALL(trace_sys_connect, unsigned int fd, struct sockaddr_in6 *in6, int addrlen)
+{
+	u16 test_case, port, dst6[8];
+	int ret, inline_ret, ret_key = 0;
+	u32 port_key;
+	void *outer_map, *inner_map;
+	bool inline_hash = false;
+
+	if (addrlen != sizeof(*in6))
+		return 0;
+
+	ret = bpf_probe_read_user(dst6, sizeof(dst6), &in6->sin6_addr);
+	if (ret) {
+		inline_ret = ret;
+		goto done;
+	}
+
+	if (dst6[0] != 0xdead || dst6[1] != 0xbeef)
+		return 0;
+
+	test_case = dst6[7];
+
+	ret = bpf_probe_read_user(&port, sizeof(port), &in6->sin6_port);
+	if (ret) {
+		inline_ret = ret;
+		goto done;
+	}
+
+	port_key = port;
+
+	ret = -ENOENT;
+	if (test_case == 0) {
+		outer_map = &a_of_port_a;
+	} else if (test_case == 1) {
+		outer_map = &h_of_port_a;
+	} else if (test_case == 2) {
+		outer_map = &h_of_port_h;
+	} else {
+		ret = __LINE__;
+		inline_ret = ret;
+		goto done;
+	}
+
+	inner_map = bpf_map_lookup_elem(outer_map, &port_key);
+	if (!inner_map) {
+		ret = __LINE__;
+		inline_ret = ret;
+		goto done;
+	}
+
+	ret = do_reg_lookup(inner_map, port_key);
+
+	if (test_case == 0 || test_case == 1)
+		inline_ret = do_inline_array_lookup(inner_map, port_key);
+	else
+		inline_ret = do_inline_hash_lookup(inner_map, port_key);
+
+done:
+	bpf_map_update_elem(&reg_result_h, &ret_key, &ret, BPF_ANY);
+	bpf_map_update_elem(&inline_result_h, &ret_key, &inline_ret, BPF_ANY);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/test_map_in_map_user.c b/samples/bpf/test_map_in_map_user.c
new file mode 100644
index 000000000..55dca43f3
--- /dev/null
+++ b/samples/bpf/test_map_in_map_user.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2017 Facebook
+ */
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <stdint.h>
+#include <assert.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#include "bpf_util.h"
+
+static int map_fd[7];
+
+#define PORT_A		(map_fd[0])
+#define PORT_H		(map_fd[1])
+#define REG_RESULT_H	(map_fd[2])
+#define INLINE_RESULT_H	(map_fd[3])
+#define A_OF_PORT_A	(map_fd[4]) /* Test case #0 */
+#define H_OF_PORT_A	(map_fd[5]) /* Test case #1 */
+#define H_OF_PORT_H	(map_fd[6]) /* Test case #2 */
+
+static const char * const test_names[] = {
+	"Array of Array",
+	"Hash of Array",
+	"Hash of Hash",
+};
+
+#define NR_TESTS ARRAY_SIZE(test_names)
+
+static void check_map_id(int inner_map_fd, int map_in_map_fd, uint32_t key)
+{
+	struct bpf_map_info info = {};
+	uint32_t info_len = sizeof(info);
+	int ret, id;
+
+	ret = bpf_map_get_info_by_fd(inner_map_fd, &info, &info_len);
+	assert(!ret);
+
+	ret = bpf_map_lookup_elem(map_in_map_fd, &key, &id);
+	assert(!ret);
+	assert(id == info.id);
+}
+
+static void populate_map(uint32_t port_key, int magic_result)
+{
+	int ret;
+
+	ret = bpf_map_update_elem(PORT_A, &port_key, &magic_result, BPF_ANY);
+	assert(!ret);
+
+	ret = bpf_map_update_elem(PORT_H, &port_key, &magic_result,
+				  BPF_NOEXIST);
+	assert(!ret);
+
+	ret = bpf_map_update_elem(A_OF_PORT_A, &port_key, &PORT_A, BPF_ANY);
+	assert(!ret);
+	check_map_id(PORT_A, A_OF_PORT_A, port_key);
+
+	ret = bpf_map_update_elem(H_OF_PORT_A, &port_key, &PORT_A, BPF_NOEXIST);
+	assert(!ret);
+	check_map_id(PORT_A, H_OF_PORT_A, port_key);
+
+	ret = bpf_map_update_elem(H_OF_PORT_H, &port_key, &PORT_H, BPF_NOEXIST);
+	assert(!ret);
+	check_map_id(PORT_H, H_OF_PORT_H, port_key);
+}
+
+static void test_map_in_map(void)
+{
+	struct sockaddr_in6 in6 = { .sin6_family = AF_INET6 };
+	uint32_t result_key = 0, port_key;
+	int result, inline_result;
+	int magic_result = 0xfaceb00c;
+	int ret;
+	int i;
+
+	port_key = rand() & 0x00FF;
+	populate_map(port_key, magic_result);
+
+	in6.sin6_addr.s6_addr16[0] = 0xdead;
+	in6.sin6_addr.s6_addr16[1] = 0xbeef;
+	in6.sin6_port = port_key;
+
+	for (i = 0; i < NR_TESTS; i++) {
+		printf("%s: ", test_names[i]);
+
+		in6.sin6_addr.s6_addr16[7] = i;
+		ret = connect(-1, (struct sockaddr *)&in6, sizeof(in6));
+		assert(ret == -1 && errno == EBADF);
+
+		ret = bpf_map_lookup_elem(REG_RESULT_H, &result_key, &result);
+		assert(!ret);
+
+		ret = bpf_map_lookup_elem(INLINE_RESULT_H, &result_key,
+					  &inline_result);
+		assert(!ret);
+
+		if (result != magic_result || inline_result != magic_result) {
+			printf("Error. result:%d inline_result:%d\n",
+			       result, inline_result);
+			exit(1);
+		}
+
+		bpf_map_delete_elem(REG_RESULT_H, &result_key);
+		bpf_map_delete_elem(INLINE_RESULT_H, &result_key);
+
+		printf("Pass\n");
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "trace_sys_connect");
+	if (!prog) {
+		printf("finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "port_a");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "port_h");
+	map_fd[2] = bpf_object__find_map_fd_by_name(obj, "reg_result_h");
+	map_fd[3] = bpf_object__find_map_fd_by_name(obj, "inline_result_h");
+	map_fd[4] = bpf_object__find_map_fd_by_name(obj, "a_of_port_a");
+	map_fd[5] = bpf_object__find_map_fd_by_name(obj, "h_of_port_a");
+	map_fd[6] = bpf_object__find_map_fd_by_name(obj, "h_of_port_h");
+	if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0 ||
+	    map_fd[3] < 0 || map_fd[4] < 0 || map_fd[5] < 0 || map_fd[6] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	test_map_in_map();
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/trace_event_kern.c b/samples/bpf/trace_event_kern.c
new file mode 100644
index 000000000..0bba5fcd7
--- /dev/null
+++ b/samples/bpf/trace_event_kern.c
@@ -0,0 +1,79 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/ptrace.h>
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/bpf_perf_event.h>
+#include <uapi/linux/perf_event.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct key_t {
+	char comm[TASK_COMM_LEN];
+	u32 kernstack;
+	u32 userstack;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct key_t);
+	__type(value, u64);
+	__uint(max_entries, 10000);
+} counts SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
+	__uint(max_entries, 10000);
+} stackmap SEC(".maps");
+
+#define KERN_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP)
+#define USER_STACKID_FLAGS (0 | BPF_F_FAST_STACK_CMP | BPF_F_USER_STACK)
+
+SEC("perf_event")
+int bpf_prog1(struct bpf_perf_event_data *ctx)
+{
+	char time_fmt1[] = "Time Enabled: %llu, Time Running: %llu";
+	char time_fmt2[] = "Get Time Failed, ErrCode: %d";
+	char addr_fmt[] = "Address recorded on event: %llx";
+	char fmt[] = "CPU-%d period %lld ip %llx";
+	u32 cpu = bpf_get_smp_processor_id();
+	struct bpf_perf_event_value value_buf;
+	struct key_t key;
+	u64 *val, one = 1;
+	int ret;
+
+	if (ctx->sample_period < 10000)
+		/* ignore warmup */
+		return 0;
+	bpf_get_current_comm(&key.comm, sizeof(key.comm));
+	key.kernstack = bpf_get_stackid(ctx, &stackmap, KERN_STACKID_FLAGS);
+	key.userstack = bpf_get_stackid(ctx, &stackmap, USER_STACKID_FLAGS);
+	if ((int)key.kernstack < 0 && (int)key.userstack < 0) {
+		bpf_trace_printk(fmt, sizeof(fmt), cpu, ctx->sample_period,
+				 PT_REGS_IP(&ctx->regs));
+		return 0;
+	}
+
+	ret = bpf_perf_prog_read_value(ctx, (void *)&value_buf, sizeof(struct bpf_perf_event_value));
+	if (!ret)
+	  bpf_trace_printk(time_fmt1, sizeof(time_fmt1), value_buf.enabled, value_buf.running);
+	else
+	  bpf_trace_printk(time_fmt2, sizeof(time_fmt2), ret);
+
+	if (ctx->addr != 0)
+	  bpf_trace_printk(addr_fmt, sizeof(addr_fmt), ctx->addr);
+
+	val = bpf_map_lookup_elem(&counts, &key);
+	if (val)
+		(*val)++;
+	else
+		bpf_map_update_elem(&counts, &key, &one, BPF_NOEXIST);
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c
new file mode 100644
index 000000000..9664749bf
--- /dev/null
+++ b/samples/bpf/trace_event_user.c
@@ -0,0 +1,352 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <linux/perf_event.h>
+#include <linux/bpf.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/resource.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "perf-sys.h"
+#include "trace_helpers.h"
+
+#define SAMPLE_FREQ 50
+
+static int pid;
+/* counts, stackmap */
+static int map_fd[2];
+struct bpf_program *prog;
+static bool sys_read_seen, sys_write_seen;
+
+static void print_ksym(__u64 addr)
+{
+	struct ksym *sym;
+
+	if (!addr)
+		return;
+	sym = ksym_search(addr);
+	if (!sym) {
+		printf("ksym not found. Is kallsyms loaded?\n");
+		return;
+	}
+
+	printf("%s;", sym->name);
+	if (!strstr(sym->name, "sys_read"))
+		sys_read_seen = true;
+	else if (!strstr(sym->name, "sys_write"))
+		sys_write_seen = true;
+}
+
+static void print_addr(__u64 addr)
+{
+	if (!addr)
+		return;
+	printf("%llx;", addr);
+}
+
+#define TASK_COMM_LEN 16
+
+struct key_t {
+	char comm[TASK_COMM_LEN];
+	__u32 kernstack;
+	__u32 userstack;
+};
+
+static void print_stack(struct key_t *key, __u64 count)
+{
+	__u64 ip[PERF_MAX_STACK_DEPTH] = {};
+	static bool warned;
+	int i;
+
+	printf("%3lld %s;", count, key->comm);
+	if (bpf_map_lookup_elem(map_fd[1], &key->kernstack, ip) != 0) {
+		printf("---;");
+	} else {
+		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
+			print_ksym(ip[i]);
+	}
+	printf("-;");
+	if (bpf_map_lookup_elem(map_fd[1], &key->userstack, ip) != 0) {
+		printf("---;");
+	} else {
+		for (i = PERF_MAX_STACK_DEPTH - 1; i >= 0; i--)
+			print_addr(ip[i]);
+	}
+	if (count < 6)
+		printf("\r");
+	else
+		printf("\n");
+
+	if (key->kernstack == -EEXIST && !warned) {
+		printf("stackmap collisions seen. Consider increasing size\n");
+		warned = true;
+	} else if ((int)key->kernstack < 0 && (int)key->userstack < 0) {
+		printf("err stackid %d %d\n", key->kernstack, key->userstack);
+	}
+}
+
+static void err_exit(int err)
+{
+	kill(pid, SIGKILL);
+	exit(err);
+}
+
+static void print_stacks(void)
+{
+	struct key_t key = {}, next_key;
+	__u64 value;
+	__u32 stackid = 0, next_id;
+	int error = 1, fd = map_fd[0], stack_map = map_fd[1];
+
+	sys_read_seen = sys_write_seen = false;
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		bpf_map_lookup_elem(fd, &next_key, &value);
+		print_stack(&next_key, value);
+		bpf_map_delete_elem(fd, &next_key);
+		key = next_key;
+	}
+	printf("\n");
+	if (!sys_read_seen || !sys_write_seen) {
+		printf("BUG kernel stack doesn't contain sys_read() and sys_write()\n");
+		err_exit(error);
+	}
+
+	/* clear stack map */
+	while (bpf_map_get_next_key(stack_map, &stackid, &next_id) == 0) {
+		bpf_map_delete_elem(stack_map, &next_id);
+		stackid = next_id;
+	}
+}
+
+static inline int generate_load(void)
+{
+	if (system("dd if=/dev/zero of=/dev/null count=5000k status=none") < 0) {
+		printf("failed to generate some load with dd: %s\n", strerror(errno));
+		return -1;
+	}
+
+	return 0;
+}
+
+static void test_perf_event_all_cpu(struct perf_event_attr *attr)
+{
+	int nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
+	struct bpf_link **links = calloc(nr_cpus, sizeof(struct bpf_link *));
+	int i, pmu_fd, error = 1;
+
+	if (!links) {
+		printf("malloc of links failed\n");
+		goto err;
+	}
+
+	/* system wide perf event, no need to inherit */
+	attr->inherit = 0;
+
+	/* open perf_event on all cpus */
+	for (i = 0; i < nr_cpus; i++) {
+		pmu_fd = sys_perf_event_open(attr, -1, i, -1, 0);
+		if (pmu_fd < 0) {
+			printf("sys_perf_event_open failed\n");
+			goto all_cpu_err;
+		}
+		links[i] = bpf_program__attach_perf_event(prog, pmu_fd);
+		if (libbpf_get_error(links[i])) {
+			printf("bpf_program__attach_perf_event failed\n");
+			links[i] = NULL;
+			close(pmu_fd);
+			goto all_cpu_err;
+		}
+	}
+
+	if (generate_load() < 0)
+		goto all_cpu_err;
+
+	print_stacks();
+	error = 0;
+all_cpu_err:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+err:
+	free(links);
+	if (error)
+		err_exit(error);
+}
+
+static void test_perf_event_task(struct perf_event_attr *attr)
+{
+	struct bpf_link *link = NULL;
+	int pmu_fd, error = 1;
+
+	/* per task perf event, enable inherit so the "dd ..." command can be traced properly.
+	 * Enabling inherit will cause bpf_perf_prog_read_time helper failure.
+	 */
+	attr->inherit = 1;
+
+	/* open task bound event */
+	pmu_fd = sys_perf_event_open(attr, 0, -1, -1, 0);
+	if (pmu_fd < 0) {
+		printf("sys_perf_event_open failed\n");
+		goto err;
+	}
+	link = bpf_program__attach_perf_event(prog, pmu_fd);
+	if (libbpf_get_error(link)) {
+		printf("bpf_program__attach_perf_event failed\n");
+		link = NULL;
+		close(pmu_fd);
+		goto err;
+	}
+
+	if (generate_load() < 0)
+		goto err;
+
+	print_stacks();
+	error = 0;
+err:
+	bpf_link__destroy(link);
+	if (error)
+		err_exit(error);
+}
+
+static void test_bpf_perf_event(void)
+{
+	struct perf_event_attr attr_type_hw = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_HARDWARE,
+		.config = PERF_COUNT_HW_CPU_CYCLES,
+	};
+	struct perf_event_attr attr_type_sw = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_SOFTWARE,
+		.config = PERF_COUNT_SW_CPU_CLOCK,
+	};
+	struct perf_event_attr attr_hw_cache_l1d = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_HW_CACHE,
+		.config =
+			PERF_COUNT_HW_CACHE_L1D |
+			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
+			(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
+	};
+	struct perf_event_attr attr_hw_cache_branch_miss = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_HW_CACHE,
+		.config =
+			PERF_COUNT_HW_CACHE_BPU |
+			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
+			(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
+	};
+	struct perf_event_attr attr_type_raw = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_RAW,
+		/* Intel Instruction Retired */
+		.config = 0xc0,
+	};
+	struct perf_event_attr attr_type_raw_lock_load = {
+		.sample_freq = SAMPLE_FREQ,
+		.freq = 1,
+		.type = PERF_TYPE_RAW,
+		/* Intel MEM_UOPS_RETIRED.LOCK_LOADS */
+		.config = 0x21d0,
+		/* Request to record lock address from PEBS */
+		.sample_type = PERF_SAMPLE_ADDR,
+		/* Record address value requires precise event */
+		.precise_ip = 2,
+	};
+
+	printf("Test HW_CPU_CYCLES\n");
+	test_perf_event_all_cpu(&attr_type_hw);
+	test_perf_event_task(&attr_type_hw);
+
+	printf("Test SW_CPU_CLOCK\n");
+	test_perf_event_all_cpu(&attr_type_sw);
+	test_perf_event_task(&attr_type_sw);
+
+	printf("Test HW_CACHE_L1D\n");
+	test_perf_event_all_cpu(&attr_hw_cache_l1d);
+	test_perf_event_task(&attr_hw_cache_l1d);
+
+	printf("Test HW_CACHE_BPU\n");
+	test_perf_event_all_cpu(&attr_hw_cache_branch_miss);
+	test_perf_event_task(&attr_hw_cache_branch_miss);
+
+	printf("Test Instruction Retired\n");
+	test_perf_event_all_cpu(&attr_type_raw);
+	test_perf_event_task(&attr_type_raw);
+
+	printf("Test Lock Load\n");
+	test_perf_event_all_cpu(&attr_type_raw_lock_load);
+	test_perf_event_task(&attr_type_raw_lock_load);
+
+	printf("*** PASS ***\n");
+}
+
+
+int main(int argc, char **argv)
+{
+	struct bpf_object *obj = NULL;
+	char filename[256];
+	int error = 1;
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	signal(SIGINT, err_exit);
+	signal(SIGTERM, err_exit);
+
+	if (load_kallsyms()) {
+		printf("failed to process /proc/kallsyms\n");
+		goto cleanup;
+	}
+
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		printf("opening BPF object file failed\n");
+		obj = NULL;
+		goto cleanup;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		printf("finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		printf("loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counts");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "stackmap");
+	if (map_fd[0] < 0 || map_fd[1] < 0) {
+		printf("finding a counts/stackmap map in obj file failed\n");
+		goto cleanup;
+	}
+
+	pid = fork();
+	if (pid == 0) {
+		read_trace_pipe();
+		return 0;
+	} else if (pid == -1) {
+		printf("couldn't spawn process\n");
+		goto cleanup;
+	}
+
+	test_bpf_perf_event();
+	error = 0;
+
+cleanup:
+	bpf_object__close(obj);
+	err_exit(error);
+}
diff --git a/samples/bpf/trace_output.bpf.c b/samples/bpf/trace_output.bpf.c
new file mode 100644
index 000000000..565a73b51
--- /dev/null
+++ b/samples/bpf/trace_output.bpf.c
@@ -0,0 +1,29 @@
+#include "vmlinux.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(u32));
+	__uint(max_entries, 2);
+} my_map SEC(".maps");
+
+SEC("ksyscall/write")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	struct S {
+		u64 pid;
+		u64 cookie;
+	} data;
+
+	data.pid = bpf_get_current_pid_tgid();
+	data.cookie = 0x12345678;
+
+	bpf_perf_event_output(ctx, &my_map, 0, &data, sizeof(data));
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/trace_output_user.c b/samples/bpf/trace_output_user.c
new file mode 100644
index 000000000..d316fd2c8
--- /dev/null
+++ b/samples/bpf/trace_output_user.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <stdio.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <time.h>
+#include <signal.h>
+#include <bpf/libbpf.h>
+
+static __u64 time_get_ns(void)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
+}
+
+static __u64 start_time;
+static __u64 cnt;
+
+#define MAX_CNT 100000ll
+
+static void print_bpf_output(void *ctx, int cpu, void *data, __u32 size)
+{
+	struct {
+		__u64 pid;
+		__u64 cookie;
+	} *e = data;
+
+	if (e->cookie != 0x12345678) {
+		printf("BUG pid %llx cookie %llx sized %d\n",
+		       e->pid, e->cookie, size);
+		return;
+	}
+
+	cnt++;
+
+	if (cnt == MAX_CNT) {
+		printf("recv %lld events per sec\n",
+		       MAX_CNT * 1000000000ll / (time_get_ns() - start_time));
+		return;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct perf_buffer *pb;
+	struct bpf_object *obj;
+	int map_fd, ret = 0;
+	char filename[256];
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (libbpf_get_error(prog)) {
+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	pb = perf_buffer__new(map_fd, 8, print_bpf_output, NULL, NULL, NULL);
+	ret = libbpf_get_error(pb);
+	if (ret) {
+		printf("failed to setup perf_buffer: %d\n", ret);
+		return 1;
+	}
+
+	f = popen("taskset 1 dd if=/dev/zero of=/dev/null", "r");
+	(void) f;
+
+	start_time = time_get_ns();
+	while ((ret = perf_buffer__poll(pb, 1000)) >= 0 && cnt < MAX_CNT) {
+	}
+	kill(0, SIGINT);
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return ret;
+}
diff --git a/samples/bpf/tracex1.bpf.c b/samples/bpf/tracex1.bpf.c
new file mode 100644
index 000000000..ceedf0b1d
--- /dev/null
+++ b/samples/bpf/tracex1.bpf.c
@@ -0,0 +1,47 @@
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "vmlinux.h"
+#include "net_shared.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_core_read.h>
+#include <bpf/bpf_tracing.h>
+
+/* kprobe is NOT a stable ABI
+ * kernel functions can be removed, renamed or completely change semantics.
+ * Number of arguments and their positions can change, etc.
+ * In such case this bpf+kprobe example will no longer be meaningful
+ */
+SEC("kprobe.multi/__netif_receive_skb_core*")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	/* attaches to kprobe __netif_receive_skb_core,
+	 * looks for packets on loopback device and prints them
+	 * (wildcard is used for avoiding symbol mismatch due to optimization)
+	 */
+	char devname[IFNAMSIZ];
+	struct net_device *dev;
+	struct sk_buff *skb;
+	int len;
+
+	bpf_core_read(&skb, sizeof(skb), (void *)PT_REGS_PARM1(ctx));
+	dev = BPF_CORE_READ(skb, dev);
+	len = BPF_CORE_READ(skb, len);
+
+	BPF_CORE_READ_STR_INTO(&devname, dev, name);
+
+	if (devname[0] == 'l' && devname[1] == 'o') {
+		char fmt[] = "skb %p len %d\n";
+		/* using bpf_trace_printk() for DEBUG ONLY */
+		bpf_trace_printk(fmt, sizeof(fmt), skb, len);
+	}
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex1_user.c b/samples/bpf/tracex1_user.c
new file mode 100644
index 000000000..8c3d9043a
--- /dev/null
+++ b/samples/bpf/tracex1_user.c
@@ -0,0 +1,50 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <unistd.h>
+#include <bpf/libbpf.h>
+#include "trace_helpers.h"
+
+int main(int ac, char **argv)
+{
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	f = popen("taskset 1 ping -c5 localhost", "r");
+	(void) f;
+
+	read_trace_pipe();
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex3.bpf.c b/samples/bpf/tracex3.bpf.c
new file mode 100644
index 000000000..41f37966f
--- /dev/null
+++ b/samples/bpf/tracex3.bpf.c
@@ -0,0 +1,100 @@
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "vmlinux.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct start_key {
+	dev_t dev;
+	u32 _pad;
+	sector_t sector;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, long);
+	__type(value, u64);
+	__uint(max_entries, 4096);
+} my_map SEC(".maps");
+
+/* from /sys/kernel/tracing/events/block/block_io_start/format */
+SEC("tracepoint/block/block_io_start")
+int bpf_prog1(struct trace_event_raw_block_rq *ctx)
+{
+	u64 val = bpf_ktime_get_ns();
+	struct start_key key = {
+		.dev = ctx->dev,
+		.sector = ctx->sector
+	};
+
+	bpf_map_update_elem(&my_map, &key, &val, BPF_ANY);
+	return 0;
+}
+
+static unsigned int log2l(unsigned long long n)
+{
+#define S(k) if (n >= (1ull << k)) { i += k; n >>= k; }
+	int i = -(n == 0);
+	S(32); S(16); S(8); S(4); S(2); S(1);
+	return i;
+#undef S
+}
+
+#define SLOTS 100
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(u64));
+	__uint(max_entries, SLOTS);
+} lat_map SEC(".maps");
+
+/* from /sys/kernel/tracing/events/block/block_io_done/format */
+SEC("tracepoint/block/block_io_done")
+int bpf_prog2(struct trace_event_raw_block_rq *ctx)
+{
+	struct start_key key = {
+		.dev = ctx->dev,
+		.sector = ctx->sector
+	};
+
+	u64 *value, l, base;
+	u32 index;
+
+	value = bpf_map_lookup_elem(&my_map, &key);
+	if (!value)
+		return 0;
+
+	u64 cur_time = bpf_ktime_get_ns();
+	u64 delta = cur_time - *value;
+
+	bpf_map_delete_elem(&my_map, &key);
+
+	/* the lines below are computing index = log10(delta)*10
+	 * using integer arithmetic
+	 * index = 29 ~ 1 usec
+	 * index = 59 ~ 1 msec
+	 * index = 89 ~ 1 sec
+	 * index = 99 ~ 10sec or more
+	 * log10(x)*10 = log2(x)*10/log2(10) = log2(x)*3
+	 */
+	l = log2l(delta);
+	base = 1ll << l;
+	index = (l * 64 + (delta - base) * 64 / base) * 3 / 64;
+
+	if (index >= SLOTS)
+		index = SLOTS - 1;
+
+	value = bpf_map_lookup_elem(&lat_map, &index);
+	if (value)
+		*value += 1;
+
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex3_user.c b/samples/bpf/tracex3_user.c
new file mode 100644
index 000000000..1002eb032
--- /dev/null
+++ b/samples/bpf/tracex3_user.c
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "bpf_util.h"
+
+#define SLOTS 100
+
+static void clear_stats(int fd)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	__u64 values[nr_cpus];
+	__u32 key;
+
+	memset(values, 0, sizeof(values));
+	for (key = 0; key < SLOTS; key++)
+		bpf_map_update_elem(fd, &key, values, BPF_ANY);
+}
+
+const char *color[] = {
+	"\033[48;5;255m",
+	"\033[48;5;252m",
+	"\033[48;5;250m",
+	"\033[48;5;248m",
+	"\033[48;5;246m",
+	"\033[48;5;244m",
+	"\033[48;5;242m",
+	"\033[48;5;240m",
+	"\033[48;5;238m",
+	"\033[48;5;236m",
+	"\033[48;5;234m",
+	"\033[48;5;232m",
+};
+const int num_colors = ARRAY_SIZE(color);
+
+const char nocolor[] = "\033[00m";
+
+const char *sym[] = {
+	" ",
+	" ",
+	".",
+	".",
+	"*",
+	"*",
+	"o",
+	"o",
+	"O",
+	"O",
+	"#",
+	"#",
+};
+
+bool full_range = false;
+bool text_only = false;
+
+static void print_banner(void)
+{
+	if (full_range)
+		printf("|1ns     |10ns     |100ns    |1us      |10us     |100us"
+		       "    |1ms      |10ms     |100ms    |1s       |10s\n");
+	else
+		printf("|1us      |10us     |100us    |1ms      |10ms     "
+		       "|100ms    |1s       |10s\n");
+}
+
+static void print_hist(int fd)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	__u64 total_events = 0;
+	long values[nr_cpus];
+	__u64 max_cnt = 0;
+	__u64 cnt[SLOTS];
+	__u64 value;
+	__u32 key;
+	int i;
+
+	for (key = 0; key < SLOTS; key++) {
+		bpf_map_lookup_elem(fd, &key, values);
+		value = 0;
+		for (i = 0; i < nr_cpus; i++)
+			value += values[i];
+		cnt[key] = value;
+		total_events += value;
+		if (value > max_cnt)
+			max_cnt = value;
+	}
+	clear_stats(fd);
+	for (key = full_range ? 0 : 29; key < SLOTS; key++) {
+		int c = num_colors * cnt[key] / (max_cnt + 1);
+
+		if (text_only)
+			printf("%s", sym[c]);
+		else
+			printf("%s %s", color[c], nocolor);
+	}
+	printf(" # %lld\n", total_events);
+}
+
+int main(int ac, char **argv)
+{
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int map_fd, i, j = 0;
+
+	for (i = 1; i < ac; i++) {
+		if (strcmp(argv[i], "-a") == 0) {
+			full_range = true;
+		} else if (strcmp(argv[i], "-t") == 0) {
+			text_only = true;
+		} else if (strcmp(argv[i], "-h") == 0) {
+			printf("Usage:\n"
+			       "  -a display wider latency range\n"
+			       "  -t text only\n");
+			return 1;
+		}
+	}
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "lat_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[j] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[j])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[j] = NULL;
+			goto cleanup;
+		}
+		j++;
+	}
+
+	printf("  heatmap of IO latency\n");
+	if (text_only)
+		printf("  %s", sym[num_colors - 1]);
+	else
+		printf("  %s %s", color[num_colors - 1], nocolor);
+	printf(" - many events with this latency\n");
+
+	if (text_only)
+		printf("  %s", sym[0]);
+	else
+		printf("  %s %s", color[0], nocolor);
+	printf(" - few events\n");
+
+	for (i = 0; ; i++) {
+		if (i % 20 == 0)
+			print_banner();
+		print_hist(map_fd);
+		sleep(2);
+	}
+
+cleanup:
+	for (j--; j >= 0; j--)
+		bpf_link__destroy(links[j]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex4.bpf.c b/samples/bpf/tracex4.bpf.c
new file mode 100644
index 000000000..d786492fd
--- /dev/null
+++ b/samples/bpf/tracex4.bpf.c
@@ -0,0 +1,54 @@
+/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "vmlinux.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+
+struct pair {
+	u64 val;
+	u64 ip;
+};
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, long);
+	__type(value, struct pair);
+	__uint(max_entries, 1000000);
+} my_map SEC(".maps");
+
+/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe
+ * example will no longer be meaningful
+ */
+SEC("kprobe/kmem_cache_free")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	long ptr = PT_REGS_PARM2(ctx);
+
+	bpf_map_delete_elem(&my_map, &ptr);
+	return 0;
+}
+
+SEC("kretprobe/kmem_cache_alloc_node_noprof")
+int bpf_prog2(struct pt_regs *ctx)
+{
+	long ptr = PT_REGS_RC(ctx);
+	long ip = 0;
+
+	/* get ip address of kmem_cache_alloc_node_noprof() caller */
+	BPF_KRETPROBE_READ_RET_IP(ip, ctx);
+
+	struct pair v = {
+		.val = bpf_ktime_get_ns(),
+		.ip = ip,
+	};
+
+	bpf_map_update_elem(&my_map, &ptr, &v, BPF_ANY);
+	return 0;
+}
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex4_user.c b/samples/bpf/tracex4_user.c
new file mode 100644
index 000000000..a5145ad72
--- /dev/null
+++ b/samples/bpf/tracex4_user.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <signal.h>
+#include <unistd.h>
+#include <stdbool.h>
+#include <string.h>
+#include <time.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+struct pair {
+	long long val;
+	__u64 ip;
+};
+
+static __u64 time_get_ns(void)
+{
+	struct timespec ts;
+
+	clock_gettime(CLOCK_MONOTONIC, &ts);
+	return ts.tv_sec * 1000000000ull + ts.tv_nsec;
+}
+
+static void print_old_objects(int fd)
+{
+	long long val = time_get_ns();
+	__u64 key, next_key;
+	struct pair v;
+
+	key = write(1, "\e[1;1H\e[2J", 11); /* clear screen */
+
+	key = -1;
+	while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
+		bpf_map_lookup_elem(fd, &next_key, &v);
+		key = next_key;
+		if (val - v.val < 1000000000ll)
+			/* object was allocated more then 1 sec ago */
+			continue;
+		printf("obj 0x%llx is %2lldsec old was allocated at ip %llx\n",
+		       next_key, (val - v.val) / 1000000000ll, v.ip);
+	}
+}
+
+int main(int ac, char **argv)
+{
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int map_fd, j = 0;
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd = bpf_object__find_map_fd_by_name(obj, "my_map");
+	if (map_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[j] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[j])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[j] = NULL;
+			goto cleanup;
+		}
+		j++;
+	}
+
+	while (1) {
+		print_old_objects(map_fd);
+		sleep(1);
+	}
+
+cleanup:
+	for (j--; j >= 0; j--)
+		bpf_link__destroy(links[j]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex5.bpf.c b/samples/bpf/tracex5.bpf.c
new file mode 100644
index 000000000..4d3d6c9b2
--- /dev/null
+++ b/samples/bpf/tracex5.bpf.c
@@ -0,0 +1,93 @@
+/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include "vmlinux.h"
+#include "syscall_nrs.h"
+#include <linux/version.h>
+#include <uapi/linux/unistd.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+#define __stringify(x) #x
+#define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
+	__uint(key_size, sizeof(u32));
+	__uint(value_size, sizeof(u32));
+#ifdef __mips__
+	__uint(max_entries, 6000); /* MIPS n64 syscalls start at 5000 */
+#else
+	__uint(max_entries, 1024);
+#endif
+} progs SEC(".maps");
+
+SEC("kprobe/__seccomp_filter")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	int sc_nr = (int)PT_REGS_PARM1(ctx);
+
+	/* dispatch into next BPF program depending on syscall number */
+	bpf_tail_call(ctx, &progs, sc_nr);
+
+	/* fall through -> unknown syscall */
+	if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) {
+		char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n";
+		bpf_trace_printk(fmt, sizeof(fmt), sc_nr);
+	}
+	return 0;
+}
+
+/* we jump here when syscall number == __NR_write */
+PROG(SYS__NR_write)(struct pt_regs *ctx)
+{
+	struct seccomp_data sd;
+
+	bpf_core_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
+	if (sd.args[2] == 512) {
+		char fmt[] = "write(fd=%d, buf=%p, size=%d)\n";
+		bpf_trace_printk(fmt, sizeof(fmt),
+				 sd.args[0], sd.args[1], sd.args[2]);
+	}
+	return 0;
+}
+
+PROG(SYS__NR_read)(struct pt_regs *ctx)
+{
+	struct seccomp_data sd;
+
+	bpf_core_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
+	if (sd.args[2] > 128 && sd.args[2] <= 1024) {
+		char fmt[] = "read(fd=%d, buf=%p, size=%d)\n";
+		bpf_trace_printk(fmt, sizeof(fmt),
+				 sd.args[0], sd.args[1], sd.args[2]);
+	}
+	return 0;
+}
+
+#ifdef __NR_mmap2
+PROG(SYS__NR_mmap2)(struct pt_regs *ctx)
+{
+	char fmt[] = "mmap2\n";
+
+	bpf_trace_printk(fmt, sizeof(fmt));
+	return 0;
+}
+#endif
+
+#ifdef __NR_mmap
+PROG(SYS__NR_mmap)(struct pt_regs *ctx)
+{
+	char fmt[] = "mmap\n";
+
+	bpf_trace_printk(fmt, sizeof(fmt));
+	return 0;
+}
+#endif
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex5_user.c b/samples/bpf/tracex5_user.c
new file mode 100644
index 000000000..7e2d8397f
--- /dev/null
+++ b/samples/bpf/tracex5_user.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <linux/filter.h>
+#include <linux/seccomp.h>
+#include <sys/prctl.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "trace_helpers.h"
+#include "bpf_util.h"
+
+#ifdef __mips__
+#define	MAX_ENTRIES  6000 /* MIPS n64 syscalls start at 5000 */
+#else
+#define	MAX_ENTRIES  1024
+#endif
+
+/* install fake seccomp program to enable seccomp code path inside the kernel,
+ * so that our kprobe attached to seccomp_phase1() can be triggered
+ */
+static void install_accept_all_seccomp(void)
+{
+	struct sock_filter filter[] = {
+		BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
+	};
+	struct sock_fprog prog = {
+		.len = (unsigned short)ARRAY_SIZE(filter),
+		.filter = filter,
+	};
+	if (prctl(PR_SET_SECCOMP, 2, &prog))
+		perror("prctl");
+}
+
+int main(int ac, char **argv)
+{
+	struct bpf_link *link = NULL;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	int key, fd, progs_fd;
+	const char *section;
+	char filename[256];
+	FILE *f;
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
+	if (!prog) {
+		printf("finding a prog in obj file failed\n");
+		goto cleanup;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	link = bpf_program__attach(prog);
+	if (libbpf_get_error(link)) {
+		fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+		link = NULL;
+		goto cleanup;
+	}
+
+	progs_fd = bpf_object__find_map_fd_by_name(obj, "progs");
+	if (progs_fd < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		section = bpf_program__section_name(prog);
+		/* register only syscalls to PROG_ARRAY */
+		if (sscanf(section, "kprobe/%d", &key) != 1)
+			continue;
+
+		fd = bpf_program__fd(prog);
+		bpf_map_update_elem(progs_fd, &key, &fd, BPF_ANY);
+	}
+
+	install_accept_all_seccomp();
+
+	f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
+	(void) f;
+
+	read_trace_pipe();
+
+cleanup:
+	bpf_link__destroy(link);
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/tracex6.bpf.c b/samples/bpf/tracex6.bpf.c
new file mode 100644
index 000000000..9b23b4737
--- /dev/null
+++ b/samples/bpf/tracex6.bpf.c
@@ -0,0 +1,81 @@
+#include "vmlinux.h"
+#include <linux/version.h>
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(u32));
+	__uint(max_entries, 64);
+} counters SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, int);
+	__type(value, u64);
+	__uint(max_entries, 64);
+} values SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, int);
+	__type(value, struct bpf_perf_event_value);
+	__uint(max_entries, 64);
+} values2 SEC(".maps");
+
+SEC("kprobe/htab_map_get_next_key")
+int bpf_prog1(struct pt_regs *ctx)
+{
+	u32 key = bpf_get_smp_processor_id();
+	u64 count, *val;
+	s64 error;
+
+	count = bpf_perf_event_read(&counters, key);
+	error = (s64)count;
+	if (error <= -2 && error >= -22)
+		return 0;
+
+	val = bpf_map_lookup_elem(&values, &key);
+	if (val)
+		*val = count;
+	else
+		bpf_map_update_elem(&values, &key, &count, BPF_NOEXIST);
+
+	return 0;
+}
+
+/*
+ * Since *_map_lookup_elem can't be expected to trigger bpf programs
+ * due to potential deadlocks (bpf_disable_instrumentation), this bpf
+ * program will be attached to bpf_map_copy_value (which is called
+ * from map_lookup_elem) and will only filter the hashtable type.
+ */
+SEC("kprobe/bpf_map_copy_value")
+int BPF_KPROBE(bpf_prog2, struct bpf_map *map)
+{
+	u32 key = bpf_get_smp_processor_id();
+	struct bpf_perf_event_value *val, buf;
+	enum bpf_map_type type;
+	int error;
+
+	type = BPF_CORE_READ(map, map_type);
+	if (type != BPF_MAP_TYPE_HASH)
+		return 0;
+
+	error = bpf_perf_event_read_value(&counters, key, &buf, sizeof(buf));
+	if (error)
+		return 0;
+
+	val = bpf_map_lookup_elem(&values2, &key);
+	if (val)
+		*val = buf;
+	else
+		bpf_map_update_elem(&values2, &key, &buf, BPF_NOEXIST);
+
+	return 0;
+}
+
+char _license[] SEC("license") = "GPL";
+u32 _version SEC("version") = LINUX_VERSION_CODE;
diff --git a/samples/bpf/tracex6_user.c b/samples/bpf/tracex6_user.c
new file mode 100644
index 000000000..ae811ac83
--- /dev/null
+++ b/samples/bpf/tracex6_user.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0
+#define _GNU_SOURCE
+
+#include <assert.h>
+#include <fcntl.h>
+#include <linux/perf_event.h>
+#include <sched.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include "perf-sys.h"
+
+#define SAMPLE_PERIOD  0x7fffffffffffffffULL
+
+/* counters, values, values2 */
+static int map_fd[3];
+
+static void check_on_cpu(int cpu, struct perf_event_attr *attr)
+{
+	struct bpf_perf_event_value value2;
+	int pmu_fd, error = 0;
+	cpu_set_t set;
+	__u64 value;
+
+	/* Move to target CPU */
+	CPU_ZERO(&set);
+	CPU_SET(cpu, &set);
+	assert(sched_setaffinity(0, sizeof(set), &set) == 0);
+	/* Open perf event and attach to the perf_event_array */
+	pmu_fd = sys_perf_event_open(attr, -1/*pid*/, cpu/*cpu*/, -1/*group_fd*/, 0);
+	if (pmu_fd < 0) {
+		fprintf(stderr, "sys_perf_event_open failed on CPU %d\n", cpu);
+		error = 1;
+		goto on_exit;
+	}
+	assert(bpf_map_update_elem(map_fd[0], &cpu, &pmu_fd, BPF_ANY) == 0);
+	assert(ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0) == 0);
+	/* Trigger the kprobe */
+	bpf_map_get_next_key(map_fd[1], &cpu, NULL);
+	/* Check the value */
+	if (bpf_map_lookup_elem(map_fd[1], &cpu, &value)) {
+		fprintf(stderr, "Value missing for CPU %d\n", cpu);
+		error = 1;
+		goto on_exit;
+	} else {
+		fprintf(stderr, "CPU %d: %llu\n", cpu, value);
+	}
+	/* The above bpf_map_lookup_elem should trigger the second kprobe */
+	if (bpf_map_lookup_elem(map_fd[2], &cpu, &value2)) {
+		fprintf(stderr, "Value2 missing for CPU %d\n", cpu);
+		error = 1;
+		goto on_exit;
+	} else {
+		fprintf(stderr, "CPU %d: counter: %llu, enabled: %llu, running: %llu\n", cpu,
+			value2.counter, value2.enabled, value2.running);
+	}
+
+on_exit:
+	assert(bpf_map_delete_elem(map_fd[0], &cpu) == 0 || error);
+	assert(ioctl(pmu_fd, PERF_EVENT_IOC_DISABLE, 0) == 0 || error);
+	assert(close(pmu_fd) == 0 || error);
+	assert(bpf_map_delete_elem(map_fd[1], &cpu) == 0 || error);
+	exit(error);
+}
+
+static void test_perf_event_array(struct perf_event_attr *attr,
+				  const char *name)
+{
+	int i, status, nr_cpus = sysconf(_SC_NPROCESSORS_CONF);
+	pid_t pid[nr_cpus];
+	int err = 0;
+
+	printf("Test reading %s counters\n", name);
+
+	for (i = 0; i < nr_cpus; i++) {
+		pid[i] = fork();
+		assert(pid[i] >= 0);
+		if (pid[i] == 0) {
+			check_on_cpu(i, attr);
+			exit(1);
+		}
+	}
+
+	for (i = 0; i < nr_cpus; i++) {
+		assert(waitpid(pid[i], &status, 0) == pid[i]);
+		err |= status;
+	}
+
+	if (err)
+		printf("Test: %s FAILED\n", name);
+}
+
+static void test_bpf_perf_event(void)
+{
+	struct perf_event_attr attr_cycles = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_HARDWARE,
+		.read_format = 0,
+		.sample_type = 0,
+		.config = PERF_COUNT_HW_CPU_CYCLES,
+	};
+	struct perf_event_attr attr_clock = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_SOFTWARE,
+		.read_format = 0,
+		.sample_type = 0,
+		.config = PERF_COUNT_SW_CPU_CLOCK,
+	};
+	struct perf_event_attr attr_raw = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_RAW,
+		.read_format = 0,
+		.sample_type = 0,
+		/* Intel Instruction Retired */
+		.config = 0xc0,
+	};
+	struct perf_event_attr attr_l1d_load = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_HW_CACHE,
+		.read_format = 0,
+		.sample_type = 0,
+		.config =
+			PERF_COUNT_HW_CACHE_L1D |
+			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
+			(PERF_COUNT_HW_CACHE_RESULT_ACCESS << 16),
+	};
+	struct perf_event_attr attr_llc_miss = {
+		.freq = 0,
+		.sample_period = SAMPLE_PERIOD,
+		.inherit = 0,
+		.type = PERF_TYPE_HW_CACHE,
+		.read_format = 0,
+		.sample_type = 0,
+		.config =
+			PERF_COUNT_HW_CACHE_LL |
+			(PERF_COUNT_HW_CACHE_OP_READ << 8) |
+			(PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
+	};
+	struct perf_event_attr attr_msr_tsc = {
+		.freq = 0,
+		.sample_period = 0,
+		.inherit = 0,
+		/* From /sys/bus/event_source/devices/msr/ */
+		.type = 7,
+		.read_format = 0,
+		.sample_type = 0,
+		.config = 0,
+	};
+
+	test_perf_event_array(&attr_cycles, "HARDWARE-cycles");
+	test_perf_event_array(&attr_clock, "SOFTWARE-clock");
+	test_perf_event_array(&attr_raw, "RAW-instruction-retired");
+	test_perf_event_array(&attr_l1d_load, "HW_CACHE-L1D-load");
+
+	/* below tests may fail in qemu */
+	test_perf_event_array(&attr_llc_miss, "HW_CACHE-LLC-miss");
+	test_perf_event_array(&attr_msr_tsc, "Dynamic-msr-tsc");
+}
+
+int main(int argc, char **argv)
+{
+	struct bpf_link *links[2];
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	char filename[256];
+	int i = 0;
+
+	snprintf(filename, sizeof(filename), "%s.bpf.o", argv[0]);
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj)) {
+		fprintf(stderr, "ERROR: opening BPF object file failed\n");
+		return 0;
+	}
+
+	/* load BPF program */
+	if (bpf_object__load(obj)) {
+		fprintf(stderr, "ERROR: loading BPF object file failed\n");
+		goto cleanup;
+	}
+
+	map_fd[0] = bpf_object__find_map_fd_by_name(obj, "counters");
+	map_fd[1] = bpf_object__find_map_fd_by_name(obj, "values");
+	map_fd[2] = bpf_object__find_map_fd_by_name(obj, "values2");
+	if (map_fd[0] < 0 || map_fd[1] < 0 || map_fd[2] < 0) {
+		fprintf(stderr, "ERROR: finding a map in obj file failed\n");
+		goto cleanup;
+	}
+
+	bpf_object__for_each_program(prog, obj) {
+		links[i] = bpf_program__attach(prog);
+		if (libbpf_get_error(links[i])) {
+			fprintf(stderr, "ERROR: bpf_program__attach failed\n");
+			links[i] = NULL;
+			goto cleanup;
+		}
+		i++;
+	}
+
+	test_bpf_perf_event();
+
+cleanup:
+	for (i--; i >= 0; i--)
+		bpf_link__destroy(links[i]);
+
+	bpf_object__close(obj);
+	return 0;
+}
diff --git a/samples/bpf/xdp2skb_meta.sh b/samples/bpf/xdp2skb_meta.sh
new file mode 100755
index 000000000..4bde9d066
--- /dev/null
+++ b/samples/bpf/xdp2skb_meta.sh
@@ -0,0 +1,220 @@
+#!/bin/bash
+#
+# SPDX-License-Identifier: GPL-2.0
+# Copyright (c) 2018 Jesper Dangaard Brouer, Red Hat Inc.
+#
+# Bash-shell example on using iproute2 tools 'tc' and 'ip' to load
+# eBPF programs, both for XDP and clsbpf.  Shell script function
+# wrappers and even long options parsing is illustrated, for ease of
+# use.
+#
+# Related to sample/bpf/xdp2skb_meta_kern.c, which contains BPF-progs
+# that need to collaborate between XDP and TC hooks.  Thus, it is
+# convenient that the same tool load both programs that need to work
+# together.
+#
+BPF_FILE=xdp2skb_meta_kern.o
+DIR=$(dirname $0)
+
+[ -z "$TC" ] && TC=tc
+[ -z "$IP" ] && IP=ip
+
+function usage() {
+    echo ""
+    echo "Usage: $0 [-vfh] --dev ethX"
+    echo "  -d | --dev     :             Network device (required)"
+    echo "  --flush        :             Cleanup flush TC and XDP progs"
+    echo "  --list         : (\$LIST)     List TC and XDP progs"
+    echo "  -v | --verbose : (\$VERBOSE)  Verbose"
+    echo "  --dry-run      : (\$DRYRUN)   Dry-run only (echo commands)"
+    echo ""
+}
+
+## -- General shell logging cmds --
+function err() {
+    local exitcode=$1
+    shift
+    echo "ERROR: $@" >&2
+    exit $exitcode
+}
+
+function info() {
+    if [[ -n "$VERBOSE" ]]; then
+	echo "# $@"
+    fi
+}
+
+## -- Helper function calls --
+
+# Wrapper call for TC and IP
+# - Will display the offending command on failure
+function _call_cmd() {
+    local cmd="$1"
+    local allow_fail="$2"
+    shift 2
+    if [[ -n "$VERBOSE" ]]; then
+	echo "$cmd $@"
+    fi
+    if [[ -n "$DRYRUN" ]]; then
+	return
+    fi
+    $cmd "$@"
+    local status=$?
+    if (( $status != 0 )); then
+	if [[ "$allow_fail" == "" ]]; then
+	    err 2 "Exec error($status) occurred cmd: \"$cmd $@\""
+	fi
+    fi
+}
+function call_tc() {
+    _call_cmd "$TC" "" "$@"
+}
+function call_tc_allow_fail() {
+    _call_cmd "$TC" "allow_fail" "$@"
+}
+function call_ip() {
+    _call_cmd "$IP" "" "$@"
+}
+
+##  --- Parse command line arguments / parameters ---
+# Using external program "getopt" to get --long-options
+OPTIONS=$(getopt -o vfhd: \
+    --long verbose,flush,help,list,dev:,dry-run -- "$@")
+if (( $? != 0 )); then
+    err 4 "Error calling getopt"
+fi
+eval set -- "$OPTIONS"
+
+unset DEV
+unset FLUSH
+while true; do
+    case "$1" in
+	-d | --dev ) # device
+	    DEV=$2
+	    info "Device set to: DEV=$DEV" >&2
+	    shift 2
+	    ;;
+	-v | --verbose)
+	    VERBOSE=yes
+	    # info "Verbose mode: VERBOSE=$VERBOSE" >&2
+	    shift
+	    ;;
+	--dry-run )
+	    DRYRUN=yes
+	    VERBOSE=yes
+	    info "Dry-run mode: enable VERBOSE and don't call TC+IP" >&2
+	    shift
+            ;;
+	-f | --flush )
+	    FLUSH=yes
+	    shift
+	    ;;
+	--list )
+	    LIST=yes
+	    shift
+	    ;;
+	-- )
+	    shift
+	    break
+	    ;;
+	-h | --help )
+	    usage;
+	    exit 0
+	    ;;
+	* )
+	    shift
+	    break
+	    ;;
+    esac
+done
+
+FILE="$DIR/$BPF_FILE"
+if [[ ! -e $FILE ]]; then
+    err 3 "Missing BPF object file ($FILE)"
+fi
+
+if [[ -z $DEV ]]; then
+    usage
+    err 2 "Please specify network device -- required option --dev"
+fi
+
+## -- Function calls --
+
+function list_tc()
+{
+    local device="$1"
+    shift
+    info "Listing current TC ingress rules"
+    call_tc filter show dev $device ingress
+}
+
+function list_xdp()
+{
+    local device="$1"
+    shift
+    info "Listing current XDP device($device) setting"
+    call_ip link show dev $device | grep --color=auto xdp
+}
+
+function flush_tc()
+{
+    local device="$1"
+    shift
+    info "Flush TC on device: $device"
+    call_tc_allow_fail filter del dev $device ingress
+    call_tc_allow_fail qdisc del dev $device clsact
+}
+
+function flush_xdp()
+{
+    local device="$1"
+    shift
+    info "Flush XDP on device: $device"
+    call_ip link set dev $device xdp off
+}
+
+function attach_tc_mark()
+{
+    local device="$1"
+    local file="$2"
+    local prog="tc_mark"
+    shift 2
+
+    # Re-attach clsact to clear/flush existing role
+    call_tc_allow_fail qdisc del dev $device clsact 2> /dev/null
+    call_tc            qdisc add dev $device clsact
+
+    # Attach BPF prog
+    call_tc filter add dev $device ingress \
+	    prio 1 handle 1 bpf da obj $file sec $prog
+}
+
+function attach_xdp_mark()
+{
+    local device="$1"
+    local file="$2"
+    local prog="xdp_mark"
+    shift 2
+
+    # Remove XDP prog in-case it's already loaded
+    # TODO: Need ip-link option to override/replace existing XDP prog
+    flush_xdp $device
+
+    # Attach XDP/BPF prog
+    call_ip link set dev $device xdp obj $file sec $prog
+}
+
+if [[ -n $FLUSH ]]; then
+    flush_tc  $DEV
+    flush_xdp $DEV
+    exit 0
+fi
+
+if [[ -n $LIST ]]; then
+    list_tc  $DEV
+    list_xdp $DEV
+    exit 0
+fi
+
+attach_tc_mark  $DEV $FILE
+attach_xdp_mark $DEV $FILE
diff --git a/samples/bpf/xdp2skb_meta_kern.c b/samples/bpf/xdp2skb_meta_kern.c
new file mode 100644
index 000000000..3c36c25d9
--- /dev/null
+++ b/samples/bpf/xdp2skb_meta_kern.c
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2018 Jesper Dangaard Brouer, Red Hat Inc.
+ *
+ * Example howto transfer info from XDP to SKB, e.g. skb->mark
+ * -----------------------------------------------------------
+ * This uses the XDP data_meta infrastructure, and is a cooperation
+ * between two bpf-programs (1) XDP and (2) clsact at TC-ingress hook.
+ *
+ * Notice: This example does not use the BPF C-loader,
+ * but instead rely on the iproute2 TC tool for loading BPF-objects.
+ */
+#include <uapi/linux/bpf.h>
+#include <uapi/linux/pkt_cls.h>
+
+#include <bpf/bpf_helpers.h>
+
+/*
+ * This struct is stored in the XDP 'data_meta' area, which is located
+ * just in-front-of the raw packet payload data.  The meaning is
+ * specific to these two BPF programs that use it as a communication
+ * channel.  XDP adjust/increase the area via a bpf-helper, and TC use
+ * boundary checks to see if data have been provided.
+ *
+ * The struct must be 4 byte aligned, which here is enforced by the
+ * struct __attribute__((aligned(4))).
+ */
+struct meta_info {
+	__u32 mark;
+} __attribute__((aligned(4)));
+
+SEC("xdp_mark")
+int _xdp_mark(struct xdp_md *ctx)
+{
+	struct meta_info *meta;
+	void *data;
+	int ret;
+
+	/* Reserve space in-front of data pointer for our meta info.
+	 * (Notice drivers not supporting data_meta will fail here!)
+	 */
+	ret = bpf_xdp_adjust_meta(ctx, -(int)sizeof(*meta));
+	if (ret < 0)
+		return XDP_ABORTED;
+
+	/* Notice: Kernel-side verifier requires that loading of
+	 * ctx->data MUST happen _after_ helper bpf_xdp_adjust_meta(),
+	 * as pkt-data pointers are invalidated.  Helpers that require
+	 * this are determined/marked by bpf_helper_changes_pkt_data()
+	 */
+	data = (void *)(unsigned long)ctx->data;
+
+	/* Check data_meta have room for meta_info struct */
+	meta = (void *)(unsigned long)ctx->data_meta;
+	if (meta + 1 > data)
+		return XDP_ABORTED;
+
+	meta->mark = 42;
+
+	return XDP_PASS;
+}
+
+SEC("tc_mark")
+int _tc_mark(struct __sk_buff *ctx)
+{
+	void *data      = (void *)(unsigned long)ctx->data;
+	void *data_meta = (void *)(unsigned long)ctx->data_meta;
+	struct meta_info *meta = data_meta;
+
+	/* Check XDP gave us some data_meta */
+	if (meta + 1 > data) {
+		ctx->mark = 41;
+		 /* Skip "accept" if no data_meta is avail */
+		return TC_ACT_OK;
+	}
+
+	/* Hint: See func tc_cls_act_is_valid_access() for BPF_WRITE access */
+	ctx->mark = meta->mark; /* Transfer XDP-mark to SKB-mark */
+
+	return TC_ACT_OK;
+}
+
+/* Manually attaching these programs:
+export DEV=ixgbe2
+export FILE=xdp2skb_meta_kern.o
+
+# via TC command
+tc qdisc del dev $DEV clsact 2> /dev/null
+tc qdisc add dev $DEV clsact
+tc filter  add dev $DEV ingress prio 1 handle 1 bpf da obj $FILE sec tc_mark
+tc filter show dev $DEV ingress
+
+# XDP via IP command:
+ip link set dev $DEV xdp off
+ip link set dev $DEV xdp obj $FILE sec xdp_mark
+
+# Use iptable to "see" if SKBs are marked
+iptables -I INPUT -p icmp -m mark --mark 41  # == 0x29
+iptables -I INPUT -p icmp -m mark --mark 42  # == 0x2a
+
+# Hint: catch XDP_ABORTED errors via
+perf record -e xdp:*
+perf script
+
+*/
diff --git a/samples/bpf/xdp_adjust_tail_kern.c b/samples/bpf/xdp_adjust_tail_kern.c
new file mode 100644
index 000000000..da67bcad1
--- /dev/null
+++ b/samples/bpf/xdp_adjust_tail_kern.c
@@ -0,0 +1,156 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2018 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program shows how to use bpf_xdp_adjust_tail() by
+ * generating ICMPv4 "packet to big" (unreachable/ df bit set frag needed
+ * to be more preice in case of v4)" where receiving packets bigger then
+ * 600 bytes.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/icmp.h>
+#include <bpf/bpf_helpers.h>
+
+#define DEFAULT_TTL 64
+#define MAX_PCKT_SIZE 600
+#define ICMP_TOOBIG_SIZE 98
+#define ICMP_TOOBIG_PAYLOAD_SIZE 92
+
+/* volatile to prevent compiler optimizations */
+static volatile __u32 max_pcktsz = MAX_PCKT_SIZE;
+
+struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, __u32);
+	__type(value, __u64);
+	__uint(max_entries, 1);
+} icmpcnt SEC(".maps");
+
+static __always_inline void count_icmp(void)
+{
+	u64 key = 0;
+	u64 *icmp_count;
+
+	icmp_count = bpf_map_lookup_elem(&icmpcnt, &key);
+	if (icmp_count)
+		*icmp_count += 1;
+}
+
+static __always_inline void swap_mac(void *data, struct ethhdr *orig_eth)
+{
+	struct ethhdr *eth;
+
+	eth = data;
+	memcpy(eth->h_source, orig_eth->h_dest, ETH_ALEN);
+	memcpy(eth->h_dest, orig_eth->h_source, ETH_ALEN);
+	eth->h_proto = orig_eth->h_proto;
+}
+
+static __always_inline __u16 csum_fold_helper(__u32 csum)
+{
+	csum = (csum & 0xffff) + (csum >> 16);
+	return ~((csum & 0xffff) + (csum >> 16));
+}
+
+static __always_inline void ipv4_csum(void *data_start, int data_size,
+				      __u32 *csum)
+{
+	*csum = bpf_csum_diff(0, 0, data_start, data_size, *csum);
+	*csum = csum_fold_helper(*csum);
+}
+
+static __always_inline int send_icmp4_too_big(struct xdp_md *xdp)
+{
+	int headroom = (int)sizeof(struct iphdr) + (int)sizeof(struct icmphdr);
+
+	if (bpf_xdp_adjust_head(xdp, 0 - headroom))
+		return XDP_DROP;
+	void *data = (void *)(long)xdp->data;
+	void *data_end = (void *)(long)xdp->data_end;
+
+	if (data + (ICMP_TOOBIG_SIZE + headroom) > data_end)
+		return XDP_DROP;
+
+	struct iphdr *iph, *orig_iph;
+	struct icmphdr *icmp_hdr;
+	struct ethhdr *orig_eth;
+	__u32 csum = 0;
+	__u64 off = 0;
+
+	orig_eth = data + headroom;
+	swap_mac(data, orig_eth);
+	off += sizeof(struct ethhdr);
+	iph = data + off;
+	off += sizeof(struct iphdr);
+	icmp_hdr = data + off;
+	off += sizeof(struct icmphdr);
+	orig_iph = data + off;
+	icmp_hdr->type = ICMP_DEST_UNREACH;
+	icmp_hdr->code = ICMP_FRAG_NEEDED;
+	icmp_hdr->un.frag.mtu = htons(max_pcktsz - sizeof(struct ethhdr));
+	icmp_hdr->checksum = 0;
+	ipv4_csum(icmp_hdr, ICMP_TOOBIG_PAYLOAD_SIZE, &csum);
+	icmp_hdr->checksum = csum;
+	iph->ttl = DEFAULT_TTL;
+	iph->daddr = orig_iph->saddr;
+	iph->saddr = orig_iph->daddr;
+	iph->version = 4;
+	iph->ihl = 5;
+	iph->protocol = IPPROTO_ICMP;
+	iph->tos = 0;
+	iph->tot_len = htons(
+		ICMP_TOOBIG_SIZE + headroom - sizeof(struct ethhdr));
+	iph->check = 0;
+	csum = 0;
+	ipv4_csum(iph, sizeof(struct iphdr), &csum);
+	iph->check = csum;
+	count_icmp();
+	return XDP_TX;
+}
+
+
+static __always_inline int handle_ipv4(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	int pckt_size = data_end - data;
+	int offset;
+
+	if (pckt_size > max(max_pcktsz, ICMP_TOOBIG_SIZE)) {
+		offset = pckt_size - ICMP_TOOBIG_SIZE;
+		if (bpf_xdp_adjust_tail(xdp, 0 - offset))
+			return XDP_PASS;
+		return send_icmp4_too_big(xdp);
+	}
+	return XDP_PASS;
+}
+
+SEC("xdp_icmp")
+int _xdp_icmp(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	struct ethhdr *eth = data;
+	__u16 h_proto;
+
+	if (eth + 1 > data_end)
+		return XDP_DROP;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == htons(ETH_P_IP))
+		return handle_ipv4(xdp);
+	else
+		return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_adjust_tail_user.c b/samples/bpf/xdp_adjust_tail_user.c
new file mode 100644
index 000000000..e9426bd65
--- /dev/null
+++ b/samples/bpf/xdp_adjust_tail_user.c
@@ -0,0 +1,198 @@
+/* SPDX-License-Identifier: GPL-2.0
+ * Copyright (c) 2018 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <net/if.h>
+#include <arpa/inet.h>
+#include <netinet/ether.h>
+#include <unistd.h>
+#include <time.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+
+#define STATS_INTERVAL_S 2U
+#define MAX_PCKT_SIZE 600
+
+static int ifindex = -1;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static __u32 prog_id;
+
+static void int_exit(int sig)
+{
+	__u32 curr_prog_id = 0;
+
+	if (ifindex > -1) {
+		if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) {
+			printf("bpf_xdp_query_id failed\n");
+			exit(1);
+		}
+		if (prog_id == curr_prog_id)
+			bpf_xdp_detach(ifindex, xdp_flags, NULL);
+		else if (!curr_prog_id)
+			printf("couldn't find a prog id on a given iface\n");
+		else
+			printf("program on interface changed, not removing\n");
+	}
+	exit(0);
+}
+
+/* simple "icmp packet too big sent" counter
+ */
+static void poll_stats(unsigned int map_fd, unsigned int kill_after_s)
+{
+	time_t started_at = time(NULL);
+	__u64 value = 0;
+	int key = 0;
+
+
+	while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
+		sleep(STATS_INTERVAL_S);
+
+		assert(bpf_map_lookup_elem(map_fd, &key, &value) == 0);
+
+		printf("icmp \"packet too big\" sent: %10llu pkts\n", value);
+	}
+}
+
+static void usage(const char *cmd)
+{
+	printf("Start a XDP prog which send ICMP \"packet too big\" \n"
+		"messages if ingress packet is bigger then MAX_SIZE bytes\n");
+	printf("Usage: %s [...]\n", cmd);
+	printf("    -i <ifname|ifindex> Interface\n");
+	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
+	printf("    -P <MAX_PCKT_SIZE> Default: %u\n", MAX_PCKT_SIZE);
+	printf("    -S use skb-mode\n");
+	printf("    -N enforce native mode\n");
+	printf("    -F force loading prog\n");
+	printf("    -h Display this help\n");
+}
+
+int main(int argc, char **argv)
+{
+	unsigned char opt_flags[256] = {};
+	const char *optstr = "i:T:P:SNFh";
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	unsigned int kill_after_s = 0;
+	int i, prog_fd, map_fd, opt;
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	__u32 max_pckt_size = 0;
+	__u32 key = 0;
+	char filename[256];
+	int err;
+
+	for (i = 0; i < strlen(optstr); i++)
+		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
+			opt_flags[(unsigned char)optstr[i]] = 1;
+
+	while ((opt = getopt(argc, argv, optstr)) != -1) {
+
+		switch (opt) {
+		case 'i':
+			ifindex = if_nametoindex(optarg);
+			if (!ifindex)
+				ifindex = atoi(optarg);
+			break;
+		case 'T':
+			kill_after_s = atoi(optarg);
+			break;
+		case 'P':
+			max_pckt_size = atoi(optarg);
+			break;
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'N':
+			/* default, set below */
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		default:
+			usage(argv[0]);
+			return 1;
+		}
+		opt_flags[opt] = 0;
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	for (i = 0; i < strlen(optstr); i++) {
+		if (opt_flags[(unsigned int)optstr[i]]) {
+			fprintf(stderr, "Missing argument -%c\n", optstr[i]);
+			usage(argv[0]);
+			return 1;
+		}
+	}
+
+	if (!ifindex) {
+		fprintf(stderr, "Invalid ifname\n");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj))
+		return 1;
+
+	prog = bpf_object__next_program(obj, NULL);
+	bpf_program__set_type(prog, BPF_PROG_TYPE_XDP);
+
+	err = bpf_object__load(obj);
+	if (err)
+		return 1;
+
+	prog_fd = bpf_program__fd(prog);
+
+	/* static global var 'max_pcktsz' is accessible from .data section */
+	if (max_pckt_size) {
+		map_fd = bpf_object__find_map_fd_by_name(obj, "xdp_adju.data");
+		if (map_fd < 0) {
+			printf("finding a max_pcktsz map in obj file failed\n");
+			return 1;
+		}
+		bpf_map_update_elem(map_fd, &key, &max_pckt_size, BPF_ANY);
+	}
+
+	/* fetch icmpcnt map */
+	map_fd = bpf_object__find_map_fd_by_name(obj, "icmpcnt");
+	if (map_fd < 0) {
+		printf("finding a icmpcnt map in obj file failed\n");
+		return 1;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	if (bpf_xdp_attach(ifindex, prog_fd, xdp_flags, NULL) < 0) {
+		printf("link set xdp fd failed\n");
+		return 1;
+	}
+
+	err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);
+	if (err) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return 1;
+	}
+	prog_id = info.id;
+
+	poll_stats(map_fd, kill_after_s);
+	int_exit(0);
+
+	return 0;
+}
diff --git a/samples/bpf/xdp_fwd_kern.c b/samples/bpf/xdp_fwd_kern.c
new file mode 100644
index 000000000..54c099cbd
--- /dev/null
+++ b/samples/bpf/xdp_fwd_kern.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2017-18 David Ahern <dsahern@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+
+#include <bpf/bpf_helpers.h>
+
+#define IPV6_FLOWINFO_MASK              cpu_to_be32(0x0FFFFFFF)
+
+struct {
+	__uint(type, BPF_MAP_TYPE_DEVMAP);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+	__uint(max_entries, 64);
+} xdp_tx_ports SEC(".maps");
+
+/* from include/net/ip.h */
+static __always_inline int ip_decrease_ttl(struct iphdr *iph)
+{
+	u32 check = (__force u32)iph->check;
+
+	check += (__force u32)htons(0x0100);
+	iph->check = (__force __sum16)(check + (check >= 0xFFFF));
+	return --iph->ttl;
+}
+
+static __always_inline int xdp_fwd_flags(struct xdp_md *ctx, u32 flags)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct bpf_fib_lookup fib_params;
+	struct ethhdr *eth = data;
+	struct ipv6hdr *ip6h;
+	struct iphdr *iph;
+	u16 h_proto;
+	u64 nh_off;
+	int rc;
+
+	nh_off = sizeof(*eth);
+	if (data + nh_off > data_end)
+		return XDP_DROP;
+
+	__builtin_memset(&fib_params, 0, sizeof(fib_params));
+
+	h_proto = eth->h_proto;
+	if (h_proto == htons(ETH_P_IP)) {
+		iph = data + nh_off;
+
+		if (iph + 1 > data_end)
+			return XDP_DROP;
+
+		if (iph->ttl <= 1)
+			return XDP_PASS;
+
+		fib_params.family	= AF_INET;
+		fib_params.tos		= iph->tos;
+		fib_params.l4_protocol	= iph->protocol;
+		fib_params.sport	= 0;
+		fib_params.dport	= 0;
+		fib_params.tot_len	= ntohs(iph->tot_len);
+		fib_params.ipv4_src	= iph->saddr;
+		fib_params.ipv4_dst	= iph->daddr;
+	} else if (h_proto == htons(ETH_P_IPV6)) {
+		struct in6_addr *src = (struct in6_addr *) fib_params.ipv6_src;
+		struct in6_addr *dst = (struct in6_addr *) fib_params.ipv6_dst;
+
+		ip6h = data + nh_off;
+		if (ip6h + 1 > data_end)
+			return XDP_DROP;
+
+		if (ip6h->hop_limit <= 1)
+			return XDP_PASS;
+
+		fib_params.family	= AF_INET6;
+		fib_params.flowinfo	= *(__be32 *)ip6h & IPV6_FLOWINFO_MASK;
+		fib_params.l4_protocol	= ip6h->nexthdr;
+		fib_params.sport	= 0;
+		fib_params.dport	= 0;
+		fib_params.tot_len	= ntohs(ip6h->payload_len);
+		*src			= ip6h->saddr;
+		*dst			= ip6h->daddr;
+	} else {
+		return XDP_PASS;
+	}
+
+	fib_params.ifindex = ctx->ingress_ifindex;
+
+	rc = bpf_fib_lookup(ctx, &fib_params, sizeof(fib_params), flags);
+	/*
+	 * Some rc (return codes) from bpf_fib_lookup() are important,
+	 * to understand how this XDP-prog interacts with network stack.
+	 *
+	 * BPF_FIB_LKUP_RET_NO_NEIGH:
+	 *  Even if route lookup was a success, then the MAC-addresses are also
+	 *  needed.  This is obtained from arp/neighbour table, but if table is
+	 *  (still) empty then BPF_FIB_LKUP_RET_NO_NEIGH is returned.  To avoid
+	 *  doing ARP lookup directly from XDP, then send packet to normal
+	 *  network stack via XDP_PASS and expect it will do ARP resolution.
+	 *
+	 * BPF_FIB_LKUP_RET_FWD_DISABLED:
+	 *  The bpf_fib_lookup respect sysctl net.ipv{4,6}.conf.all.forwarding
+	 *  setting, and will return BPF_FIB_LKUP_RET_FWD_DISABLED if not
+	 *  enabled this on ingress device.
+	 */
+	if (rc == BPF_FIB_LKUP_RET_SUCCESS) {
+		/* Verify egress index has been configured as TX-port.
+		 * (Note: User can still have inserted an egress ifindex that
+		 * doesn't support XDP xmit, which will result in packet drops).
+		 *
+		 * Note: lookup in devmap supported since 0cdbb4b09a0.
+		 * If not supported will fail with:
+		 *  cannot pass map_type 14 into func bpf_map_lookup_elem#1:
+		 */
+		if (!bpf_map_lookup_elem(&xdp_tx_ports, &fib_params.ifindex))
+			return XDP_PASS;
+
+		if (h_proto == htons(ETH_P_IP))
+			ip_decrease_ttl(iph);
+		else if (h_proto == htons(ETH_P_IPV6))
+			ip6h->hop_limit--;
+
+		memcpy(eth->h_dest, fib_params.dmac, ETH_ALEN);
+		memcpy(eth->h_source, fib_params.smac, ETH_ALEN);
+		return bpf_redirect_map(&xdp_tx_ports, fib_params.ifindex, 0);
+	}
+
+	return XDP_PASS;
+}
+
+SEC("xdp_fwd")
+int xdp_fwd_prog(struct xdp_md *ctx)
+{
+	return xdp_fwd_flags(ctx, 0);
+}
+
+SEC("xdp_fwd_direct")
+int xdp_fwd_direct_prog(struct xdp_md *ctx)
+{
+	return xdp_fwd_flags(ctx, BPF_FIB_LOOKUP_DIRECT);
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_fwd_user.c b/samples/bpf/xdp_fwd_user.c
new file mode 100644
index 000000000..193b3b79b
--- /dev/null
+++ b/samples/bpf/xdp_fwd_user.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2017-18 David Ahern <dsahern@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <linux/limits.h>
+#include <net/if.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <libgen.h>
+
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+
+static int do_attach(int idx, int prog_fd, int map_fd, const char *name)
+{
+	int err;
+
+	err = bpf_xdp_attach(idx, prog_fd, xdp_flags, NULL);
+	if (err < 0) {
+		printf("ERROR: failed to attach program to %s\n", name);
+		return err;
+	}
+
+	/* Adding ifindex as a possible egress TX port */
+	err = bpf_map_update_elem(map_fd, &idx, &idx, 0);
+	if (err)
+		printf("ERROR: failed using device %s as TX-port\n", name);
+
+	return err;
+}
+
+static int do_detach(int ifindex, const char *ifname, const char *app_name)
+{
+	LIBBPF_OPTS(bpf_xdp_attach_opts, opts);
+	struct bpf_prog_info prog_info = {};
+	char prog_name[BPF_OBJ_NAME_LEN];
+	__u32 info_len, curr_prog_id;
+	int prog_fd;
+	int err = 1;
+
+	if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) {
+		printf("ERROR: bpf_xdp_query_id failed (%s)\n",
+		       strerror(errno));
+		return err;
+	}
+
+	if (!curr_prog_id) {
+		printf("ERROR: flags(0x%x) xdp prog is not attached to %s\n",
+		       xdp_flags, ifname);
+		return err;
+	}
+
+	info_len = sizeof(prog_info);
+	prog_fd = bpf_prog_get_fd_by_id(curr_prog_id);
+	if (prog_fd < 0) {
+		printf("ERROR: bpf_prog_get_fd_by_id failed (%s)\n",
+		       strerror(errno));
+		return prog_fd;
+	}
+
+	err = bpf_prog_get_info_by_fd(prog_fd, &prog_info, &info_len);
+	if (err) {
+		printf("ERROR: bpf_prog_get_info_by_fd failed (%s)\n",
+		       strerror(errno));
+		goto close_out;
+	}
+	snprintf(prog_name, sizeof(prog_name), "%s_prog", app_name);
+	prog_name[BPF_OBJ_NAME_LEN - 1] = '\0';
+
+	if (strcmp(prog_info.name, prog_name)) {
+		printf("ERROR: %s isn't attached to %s\n", app_name, ifname);
+		err = 1;
+		goto close_out;
+	}
+
+	opts.old_prog_fd = prog_fd;
+	err = bpf_xdp_detach(ifindex, xdp_flags, &opts);
+	if (err < 0)
+		printf("ERROR: failed to detach program from %s (%s)\n",
+		       ifname, strerror(errno));
+	/* TODO: Remember to cleanup map, when adding use of shared map
+	 *  bpf_map_delete_elem((map_fd, &idx);
+	 */
+close_out:
+	close(prog_fd);
+	return err;
+}
+
+static void usage(const char *prog)
+{
+	fprintf(stderr,
+		"usage: %s [OPTS] interface-list\n"
+		"\nOPTS:\n"
+		"    -d    detach program\n"
+		"    -S    use skb-mode\n"
+		"    -F    force loading prog\n"
+		"    -D    direct table lookups (skip fib rules)\n",
+		prog);
+}
+
+int main(int argc, char **argv)
+{
+	const char *prog_name = "xdp_fwd";
+	struct bpf_program *prog = NULL;
+	struct bpf_program *pos;
+	const char *sec_name;
+	int prog_fd = -1, map_fd = -1;
+	char filename[PATH_MAX];
+	struct bpf_object *obj;
+	int opt, i, idx, err;
+	int attach = 1;
+	int ret = 0;
+
+	while ((opt = getopt(argc, argv, ":dDSF")) != -1) {
+		switch (opt) {
+		case 'd':
+			attach = 0;
+			break;
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		case 'D':
+			prog_name = "xdp_fwd_direct";
+			break;
+		default:
+			usage(basename(argv[0]));
+			return 1;
+		}
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	if (optind == argc) {
+		usage(basename(argv[0]));
+		return 1;
+	}
+
+	if (attach) {
+		snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+		if (access(filename, O_RDONLY) < 0) {
+			printf("error accessing file %s: %s\n",
+				filename, strerror(errno));
+			return 1;
+		}
+
+		obj = bpf_object__open_file(filename, NULL);
+		if (libbpf_get_error(obj))
+			return 1;
+
+		prog = bpf_object__next_program(obj, NULL);
+		bpf_program__set_type(prog, BPF_PROG_TYPE_XDP);
+
+		err = bpf_object__load(obj);
+		if (err) {
+			printf("Does kernel support devmap lookup?\n");
+			/* If not, the error message will be:
+			 *  "cannot pass map_type 14 into func bpf_map_lookup_elem#1"
+			 */
+			return 1;
+		}
+
+		bpf_object__for_each_program(pos, obj) {
+			sec_name = bpf_program__section_name(pos);
+			if (sec_name && !strcmp(sec_name, prog_name)) {
+				prog = pos;
+				break;
+			}
+		}
+		prog_fd = bpf_program__fd(prog);
+		if (prog_fd < 0) {
+			printf("program not found: %s\n", strerror(prog_fd));
+			return 1;
+		}
+		map_fd = bpf_map__fd(bpf_object__find_map_by_name(obj,
+							"xdp_tx_ports"));
+		if (map_fd < 0) {
+			printf("map not found: %s\n", strerror(map_fd));
+			return 1;
+		}
+	}
+
+	for (i = optind; i < argc; ++i) {
+		idx = if_nametoindex(argv[i]);
+		if (!idx)
+			idx = strtoul(argv[i], NULL, 0);
+
+		if (!idx) {
+			fprintf(stderr, "Invalid arg\n");
+			return 1;
+		}
+		if (!attach) {
+			err = do_detach(idx, argv[i], prog_name);
+			if (err)
+				ret = err;
+		} else {
+			err = do_attach(idx, prog_fd, map_fd, argv[i]);
+			if (err)
+				ret = err;
+		}
+	}
+
+	return ret;
+}
diff --git a/samples/bpf/xdp_router_ipv4.bpf.c b/samples/bpf/xdp_router_ipv4.bpf.c
new file mode 100644
index 000000000..0643330d1
--- /dev/null
+++ b/samples/bpf/xdp_router_ipv4.bpf.c
@@ -0,0 +1,189 @@
+/* Copyright (C) 2017 Cavium, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#include "vmlinux.h"
+#include "xdp_sample.bpf.h"
+#include "xdp_sample_shared.h"
+
+#define ETH_ALEN	6
+#define ETH_P_8021Q	0x8100
+#define ETH_P_8021AD	0x88A8
+
+struct trie_value {
+	__u8 prefix[4];
+	__be64 value;
+	int ifindex;
+	int metric;
+	__be32 gw;
+};
+
+/* Key for lpm_trie */
+union key_4 {
+	u32 b32[2];
+	u8 b8[8];
+};
+
+struct arp_entry {
+	__be64 mac;
+	__be32 dst;
+};
+
+struct direct_map {
+	struct arp_entry arp;
+	int ifindex;
+	__be64 mac;
+};
+
+/* Map for trie implementation */
+struct {
+	__uint(type, BPF_MAP_TYPE_LPM_TRIE);
+	__uint(key_size, 8);
+	__uint(value_size, sizeof(struct trie_value));
+	__uint(max_entries, 50);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+} lpm_map SEC(".maps");
+
+/* Map for ARP table */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __be32);
+	__type(value, __be64);
+	__uint(max_entries, 50);
+} arp_table SEC(".maps");
+
+/* Map to keep the exact match entries in the route table */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __be32);
+	__type(value, struct direct_map);
+	__uint(max_entries, 50);
+} exact_match SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_DEVMAP);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+	__uint(max_entries, 100);
+} tx_port SEC(".maps");
+
+SEC("xdp")
+int xdp_router_ipv4_prog(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	u64 nh_off = sizeof(*eth);
+	struct datarec *rec;
+	__be16 h_proto;
+	u32 key = 0;
+
+	rec = bpf_map_lookup_elem(&rx_cnt, &key);
+	if (rec)
+		NO_TEAR_INC(rec->processed);
+
+	if (data + nh_off > data_end)
+		goto drop;
+
+	h_proto = eth->h_proto;
+	if (h_proto == bpf_htons(ETH_P_8021Q) ||
+	    h_proto == bpf_htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			goto drop;
+
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+
+	switch (bpf_ntohs(h_proto)) {
+	case ETH_P_ARP:
+		if (rec)
+			NO_TEAR_INC(rec->xdp_pass);
+		return XDP_PASS;
+	case ETH_P_IP: {
+		struct iphdr *iph = data + nh_off;
+		struct direct_map *direct_entry;
+		__be64 *dest_mac, *src_mac;
+		int forward_to;
+
+		if (iph + 1 > data_end)
+			goto drop;
+
+		direct_entry = bpf_map_lookup_elem(&exact_match, &iph->daddr);
+
+		/* Check for exact match, this would give a faster lookup */
+		if (direct_entry && direct_entry->mac &&
+		    direct_entry->arp.mac) {
+			src_mac = &direct_entry->mac;
+			dest_mac = &direct_entry->arp.mac;
+			forward_to = direct_entry->ifindex;
+		} else {
+			struct trie_value *prefix_value;
+			union key_4 key4;
+
+			/* Look up in the trie for lpm */
+			key4.b32[0] = 32;
+			key4.b8[4] = iph->daddr & 0xff;
+			key4.b8[5] = (iph->daddr >> 8) & 0xff;
+			key4.b8[6] = (iph->daddr >> 16) & 0xff;
+			key4.b8[7] = (iph->daddr >> 24) & 0xff;
+
+			prefix_value = bpf_map_lookup_elem(&lpm_map, &key4);
+			if (!prefix_value)
+				goto drop;
+
+			forward_to = prefix_value->ifindex;
+			src_mac = &prefix_value->value;
+			if (!src_mac)
+				goto drop;
+
+			dest_mac = bpf_map_lookup_elem(&arp_table, &iph->daddr);
+			if (!dest_mac) {
+				if (!prefix_value->gw)
+					goto drop;
+
+				dest_mac = bpf_map_lookup_elem(&arp_table,
+							       &prefix_value->gw);
+				if (!dest_mac) {
+					/* Forward the packet to the kernel in
+					 * order to trigger ARP discovery for
+					 * the default gw.
+					 */
+					if (rec)
+						NO_TEAR_INC(rec->xdp_pass);
+					return XDP_PASS;
+				}
+			}
+		}
+
+		if (src_mac && dest_mac) {
+			int ret;
+
+			__builtin_memcpy(eth->h_dest, dest_mac, ETH_ALEN);
+			__builtin_memcpy(eth->h_source, src_mac, ETH_ALEN);
+
+			ret = bpf_redirect_map(&tx_port, forward_to, 0);
+			if (ret == XDP_REDIRECT) {
+				if (rec)
+					NO_TEAR_INC(rec->xdp_redirect);
+				return ret;
+			}
+		}
+	}
+	default:
+		break;
+	}
+drop:
+	if (rec)
+		NO_TEAR_INC(rec->xdp_drop);
+
+	return XDP_DROP;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c
new file mode 100644
index 000000000..266fdd0b0
--- /dev/null
+++ b/samples/bpf/xdp_router_ipv4_user.c
@@ -0,0 +1,699 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (C) 2017 Cavium, Inc.
+ */
+#include <linux/bpf.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <unistd.h>
+#include <bpf/bpf.h>
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <net/if.h>
+#include <netdb.h>
+#include <sys/ioctl.h>
+#include <sys/syscall.h>
+#include "bpf_util.h"
+#include <bpf/libbpf.h>
+#include <libgen.h>
+#include <getopt.h>
+#include <pthread.h>
+#include "xdp_sample_user.h"
+#include "xdp_router_ipv4.skel.h"
+
+static const char *__doc__ =
+"XDP IPv4 router implementation\n"
+"Usage: xdp_router_ipv4 <IFNAME-0> ... <IFNAME-N>\n";
+
+static char buf[8192];
+static int lpm_map_fd;
+static int arp_table_map_fd;
+static int exact_match_map_fd;
+static int tx_port_map_fd;
+
+static bool routes_thread_exit;
+static int interval = 5;
+
+static int mask = SAMPLE_RX_CNT | SAMPLE_REDIRECT_ERR_MAP_CNT |
+		  SAMPLE_DEVMAP_XMIT_CNT_MULTI | SAMPLE_EXCEPTION_CNT;
+
+DEFINE_SAMPLE_INIT(xdp_router_ipv4);
+
+static const struct option long_options[] = {
+	{ "help", no_argument, NULL, 'h' },
+	{ "skb-mode", no_argument, NULL, 'S' },
+	{ "force", no_argument, NULL, 'F' },
+	{ "interval", required_argument, NULL, 'i' },
+	{ "verbose", no_argument, NULL, 'v' },
+	{ "stats", no_argument, NULL, 's' },
+	{}
+};
+
+static int get_route_table(int rtm_family);
+
+static int recv_msg(struct sockaddr_nl sock_addr, int sock)
+{
+	struct nlmsghdr *nh;
+	int len, nll = 0;
+	char *buf_ptr;
+
+	buf_ptr = buf;
+	while (1) {
+		len = recv(sock, buf_ptr, sizeof(buf) - nll, 0);
+		if (len < 0)
+			return len;
+
+		nh = (struct nlmsghdr *)buf_ptr;
+
+		if (nh->nlmsg_type == NLMSG_DONE)
+			break;
+		buf_ptr += len;
+		nll += len;
+		if ((sock_addr.nl_groups & RTMGRP_NEIGH) == RTMGRP_NEIGH)
+			break;
+
+		if ((sock_addr.nl_groups & RTMGRP_IPV4_ROUTE) == RTMGRP_IPV4_ROUTE)
+			break;
+	}
+	return nll;
+}
+
+/* Function to parse the route entry returned by netlink
+ * Updates the route entry related map entries
+ */
+static void read_route(struct nlmsghdr *nh, int nll)
+{
+	char dsts[24], gws[24], ifs[16], dsts_len[24], metrics[24];
+	struct bpf_lpm_trie_key_u8 *prefix_key;
+	struct rtattr *rt_attr;
+	struct rtmsg *rt_msg;
+	int rtm_family;
+	int rtl;
+	int i;
+	struct route_table {
+		int  dst_len, iface, metric;
+		__be32 dst, gw;
+		__be64 mac;
+	} route;
+	struct arp_table {
+		__be64 mac;
+		__be32 dst;
+	};
+
+	struct direct_map {
+		struct arp_table arp;
+		int ifindex;
+		__be64 mac;
+	} direct_entry;
+
+	memset(&route, 0, sizeof(route));
+	for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) {
+		rt_msg = (struct rtmsg *)NLMSG_DATA(nh);
+		rtm_family = rt_msg->rtm_family;
+		if (rtm_family == AF_INET)
+			if (rt_msg->rtm_table != RT_TABLE_MAIN)
+				continue;
+		rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
+		rtl = RTM_PAYLOAD(nh);
+
+		for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
+			switch (rt_attr->rta_type) {
+			case NDA_DST:
+				sprintf(dsts, "%u",
+					(*((__be32 *)RTA_DATA(rt_attr))));
+				break;
+			case RTA_GATEWAY:
+				sprintf(gws, "%u",
+					*((__be32 *)RTA_DATA(rt_attr)));
+				break;
+			case RTA_OIF:
+				sprintf(ifs, "%u",
+					*((int *)RTA_DATA(rt_attr)));
+				break;
+			case RTA_METRICS:
+				sprintf(metrics, "%u",
+					*((int *)RTA_DATA(rt_attr)));
+			default:
+				break;
+			}
+		}
+		sprintf(dsts_len, "%d", rt_msg->rtm_dst_len);
+		route.dst = atoi(dsts);
+		route.dst_len = atoi(dsts_len);
+		route.gw = atoi(gws);
+		route.iface = atoi(ifs);
+		route.metric = atoi(metrics);
+		assert(get_mac_addr(route.iface, &route.mac) == 0);
+		assert(bpf_map_update_elem(tx_port_map_fd,
+					   &route.iface, &route.iface, 0) == 0);
+		if (rtm_family == AF_INET) {
+			struct trie_value {
+				__u8 prefix[4];
+				__be64 value;
+				int ifindex;
+				int metric;
+				__be32 gw;
+			} *prefix_value;
+
+			prefix_key = alloca(sizeof(*prefix_key) + 4);
+			prefix_value = alloca(sizeof(*prefix_value));
+
+			prefix_key->prefixlen = 32;
+			prefix_key->prefixlen = route.dst_len;
+			direct_entry.mac = route.mac & 0xffffffffffff;
+			direct_entry.ifindex = route.iface;
+			direct_entry.arp.mac = 0;
+			direct_entry.arp.dst = 0;
+			if (route.dst_len == 32) {
+				if (nh->nlmsg_type == RTM_DELROUTE) {
+					assert(bpf_map_delete_elem(exact_match_map_fd,
+								   &route.dst) == 0);
+				} else {
+					if (bpf_map_lookup_elem(arp_table_map_fd,
+								&route.dst,
+								&direct_entry.arp.mac) == 0)
+						direct_entry.arp.dst = route.dst;
+					assert(bpf_map_update_elem(exact_match_map_fd,
+								   &route.dst,
+								   &direct_entry, 0) == 0);
+				}
+			}
+			for (i = 0; i < 4; i++)
+				prefix_key->data[i] = (route.dst >> i * 8) & 0xff;
+
+			if (bpf_map_lookup_elem(lpm_map_fd, prefix_key,
+						prefix_value) < 0) {
+				for (i = 0; i < 4; i++)
+					prefix_value->prefix[i] = prefix_key->data[i];
+				prefix_value->value = route.mac & 0xffffffffffff;
+				prefix_value->ifindex = route.iface;
+				prefix_value->gw = route.gw;
+				prefix_value->metric = route.metric;
+
+				assert(bpf_map_update_elem(lpm_map_fd,
+							   prefix_key,
+							   prefix_value, 0
+							   ) == 0);
+			} else {
+				if (nh->nlmsg_type == RTM_DELROUTE) {
+					assert(bpf_map_delete_elem(lpm_map_fd,
+								   prefix_key
+								   ) == 0);
+					/* Rereading the route table to check if
+					 * there is an entry with the same
+					 * prefix but a different metric as the
+					 * deleted entry.
+					 */
+					get_route_table(AF_INET);
+				} else if (prefix_key->data[0] ==
+					   prefix_value->prefix[0] &&
+					   prefix_key->data[1] ==
+					   prefix_value->prefix[1] &&
+					   prefix_key->data[2] ==
+					   prefix_value->prefix[2] &&
+					   prefix_key->data[3] ==
+					   prefix_value->prefix[3] &&
+					   route.metric >= prefix_value->metric) {
+					continue;
+				} else {
+					for (i = 0; i < 4; i++)
+						prefix_value->prefix[i] =
+							prefix_key->data[i];
+					prefix_value->value =
+						route.mac & 0xffffffffffff;
+					prefix_value->ifindex = route.iface;
+					prefix_value->gw = route.gw;
+					prefix_value->metric = route.metric;
+					assert(bpf_map_update_elem(lpm_map_fd,
+								   prefix_key,
+								   prefix_value,
+								   0) == 0);
+				}
+			}
+		}
+		memset(&route, 0, sizeof(route));
+		memset(dsts, 0, sizeof(dsts));
+		memset(dsts_len, 0, sizeof(dsts_len));
+		memset(gws, 0, sizeof(gws));
+		memset(ifs, 0, sizeof(ifs));
+		memset(&route, 0, sizeof(route));
+	}
+}
+
+/* Function to read the existing route table  when the process is launched*/
+static int get_route_table(int rtm_family)
+{
+	struct sockaddr_nl sa;
+	struct nlmsghdr *nh;
+	int sock, seq = 0;
+	struct msghdr msg;
+	struct iovec iov;
+	int ret = 0;
+	int nll;
+
+	struct {
+		struct nlmsghdr nl;
+		struct rtmsg rt;
+		char buf[8192];
+	} req;
+
+	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock < 0) {
+		fprintf(stderr, "open netlink socket: %s\n", strerror(errno));
+		return -errno;
+	}
+	memset(&sa, 0, sizeof(sa));
+	sa.nl_family = AF_NETLINK;
+	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
+		fprintf(stderr, "bind netlink socket: %s\n", strerror(errno));
+		ret = -errno;
+		goto cleanup;
+	}
+	memset(&req, 0, sizeof(req));
+	req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+	req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
+	req.nl.nlmsg_type = RTM_GETROUTE;
+
+	req.rt.rtm_family = rtm_family;
+	req.rt.rtm_table = RT_TABLE_MAIN;
+	req.nl.nlmsg_pid = 0;
+	req.nl.nlmsg_seq = ++seq;
+	memset(&msg, 0, sizeof(msg));
+	iov.iov_base = (void *)&req.nl;
+	iov.iov_len = req.nl.nlmsg_len;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	ret = sendmsg(sock, &msg, 0);
+	if (ret < 0) {
+		fprintf(stderr, "send to netlink: %s\n", strerror(errno));
+		ret = -errno;
+		goto cleanup;
+	}
+	memset(buf, 0, sizeof(buf));
+	nll = recv_msg(sa, sock);
+	if (nll < 0) {
+		fprintf(stderr, "recv from netlink: %s\n", strerror(nll));
+		ret = nll;
+		goto cleanup;
+	}
+	nh = (struct nlmsghdr *)buf;
+	read_route(nh, nll);
+cleanup:
+	close(sock);
+	return ret;
+}
+
+/* Function to parse the arp entry returned by netlink
+ * Updates the arp entry related map entries
+ */
+static void read_arp(struct nlmsghdr *nh, int nll)
+{
+	struct rtattr *rt_attr;
+	char dsts[24], mac[24];
+	struct ndmsg *rt_msg;
+	int rtl, ndm_family;
+
+	struct arp_table {
+		__be64 mac;
+		__be32 dst;
+	} arp_entry;
+	struct direct_map {
+		struct arp_table arp;
+		int ifindex;
+		__be64 mac;
+	} direct_entry;
+
+	for (; NLMSG_OK(nh, nll); nh = NLMSG_NEXT(nh, nll)) {
+		rt_msg = (struct ndmsg *)NLMSG_DATA(nh);
+		rt_attr = (struct rtattr *)RTM_RTA(rt_msg);
+		ndm_family = rt_msg->ndm_family;
+		rtl = RTM_PAYLOAD(nh);
+		for (; RTA_OK(rt_attr, rtl); rt_attr = RTA_NEXT(rt_attr, rtl)) {
+			switch (rt_attr->rta_type) {
+			case NDA_DST:
+				sprintf(dsts, "%u",
+					*((__be32 *)RTA_DATA(rt_attr)));
+				break;
+			case NDA_LLADDR:
+				sprintf(mac, "%lld",
+					*((__be64 *)RTA_DATA(rt_attr)));
+				break;
+			default:
+				break;
+			}
+		}
+		arp_entry.dst = atoi(dsts);
+		arp_entry.mac = atol(mac);
+
+		if (ndm_family == AF_INET) {
+			if (bpf_map_lookup_elem(exact_match_map_fd,
+						&arp_entry.dst,
+						&direct_entry) == 0) {
+				if (nh->nlmsg_type == RTM_DELNEIGH) {
+					direct_entry.arp.dst = 0;
+					direct_entry.arp.mac = 0;
+				} else if (nh->nlmsg_type == RTM_NEWNEIGH) {
+					direct_entry.arp.dst = arp_entry.dst;
+					direct_entry.arp.mac = arp_entry.mac;
+				}
+				assert(bpf_map_update_elem(exact_match_map_fd,
+							   &arp_entry.dst,
+							   &direct_entry, 0
+							   ) == 0);
+				memset(&direct_entry, 0, sizeof(direct_entry));
+			}
+			if (nh->nlmsg_type == RTM_DELNEIGH) {
+				assert(bpf_map_delete_elem(arp_table_map_fd,
+							   &arp_entry.dst) == 0);
+			} else if (nh->nlmsg_type == RTM_NEWNEIGH) {
+				assert(bpf_map_update_elem(arp_table_map_fd,
+							   &arp_entry.dst,
+							   &arp_entry.mac, 0
+							   ) == 0);
+			}
+		}
+		memset(&arp_entry, 0, sizeof(arp_entry));
+		memset(dsts, 0, sizeof(dsts));
+	}
+}
+
+/* Function to read the existing arp table  when the process is launched*/
+static int get_arp_table(int rtm_family)
+{
+	struct sockaddr_nl sa;
+	struct nlmsghdr *nh;
+	int sock, seq = 0;
+	struct msghdr msg;
+	struct iovec iov;
+	int ret = 0;
+	int nll;
+	struct {
+		struct nlmsghdr nl;
+		struct ndmsg rt;
+		char buf[8192];
+	} req;
+
+	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock < 0) {
+		fprintf(stderr, "open netlink socket: %s\n", strerror(errno));
+		return -errno;
+	}
+	memset(&sa, 0, sizeof(sa));
+	sa.nl_family = AF_NETLINK;
+	if (bind(sock, (struct sockaddr *)&sa, sizeof(sa)) < 0) {
+		fprintf(stderr, "bind netlink socket: %s\n", strerror(errno));
+		ret = -errno;
+		goto cleanup;
+	}
+	memset(&req, 0, sizeof(req));
+	req.nl.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+	req.nl.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
+	req.nl.nlmsg_type = RTM_GETNEIGH;
+	req.rt.ndm_state = NUD_REACHABLE;
+	req.rt.ndm_family = rtm_family;
+	req.nl.nlmsg_pid = 0;
+	req.nl.nlmsg_seq = ++seq;
+	memset(&msg, 0, sizeof(msg));
+	iov.iov_base = (void *)&req.nl;
+	iov.iov_len = req.nl.nlmsg_len;
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+	ret = sendmsg(sock, &msg, 0);
+	if (ret < 0) {
+		fprintf(stderr, "send to netlink: %s\n", strerror(errno));
+		ret = -errno;
+		goto cleanup;
+	}
+	memset(buf, 0, sizeof(buf));
+	nll = recv_msg(sa, sock);
+	if (nll < 0) {
+		fprintf(stderr, "recv from netlink: %s\n", strerror(nll));
+		ret = nll;
+		goto cleanup;
+	}
+	nh = (struct nlmsghdr *)buf;
+	read_arp(nh, nll);
+cleanup:
+	close(sock);
+	return ret;
+}
+
+/* Function to keep track and update changes in route and arp table
+ * Give regular statistics of packets forwarded
+ */
+static void *monitor_routes_thread(void *arg)
+{
+	struct pollfd fds_route, fds_arp;
+	struct sockaddr_nl la, lr;
+	int sock, sock_arp, nll;
+	struct nlmsghdr *nh;
+
+	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock < 0) {
+		fprintf(stderr, "open netlink socket: %s\n", strerror(errno));
+		return NULL;
+	}
+
+	fcntl(sock, F_SETFL, O_NONBLOCK);
+	memset(&lr, 0, sizeof(lr));
+	lr.nl_family = AF_NETLINK;
+	lr.nl_groups = RTMGRP_IPV6_ROUTE | RTMGRP_IPV4_ROUTE | RTMGRP_NOTIFY;
+	if (bind(sock, (struct sockaddr *)&lr, sizeof(lr)) < 0) {
+		fprintf(stderr, "bind netlink socket: %s\n", strerror(errno));
+		close(sock);
+		return NULL;
+	}
+
+	fds_route.fd = sock;
+	fds_route.events = POLL_IN;
+
+	sock_arp = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+	if (sock_arp < 0) {
+		fprintf(stderr, "open netlink socket: %s\n", strerror(errno));
+		close(sock);
+		return NULL;
+	}
+
+	fcntl(sock_arp, F_SETFL, O_NONBLOCK);
+	memset(&la, 0, sizeof(la));
+	la.nl_family = AF_NETLINK;
+	la.nl_groups = RTMGRP_NEIGH | RTMGRP_NOTIFY;
+	if (bind(sock_arp, (struct sockaddr *)&la, sizeof(la)) < 0) {
+		fprintf(stderr, "bind netlink socket: %s\n", strerror(errno));
+		goto cleanup;
+	}
+
+	fds_arp.fd = sock_arp;
+	fds_arp.events = POLL_IN;
+
+	/* dump route and arp tables */
+	if (get_arp_table(AF_INET) < 0) {
+		fprintf(stderr, "Failed reading arp table\n");
+		goto cleanup;
+	}
+
+	if (get_route_table(AF_INET) < 0) {
+		fprintf(stderr, "Failed reading route table\n");
+		goto cleanup;
+	}
+
+	while (!routes_thread_exit) {
+		memset(buf, 0, sizeof(buf));
+		if (poll(&fds_route, 1, 3) == POLL_IN) {
+			nll = recv_msg(lr, sock);
+			if (nll < 0) {
+				fprintf(stderr, "recv from netlink: %s\n",
+					strerror(nll));
+				goto cleanup;
+			}
+
+			nh = (struct nlmsghdr *)buf;
+			read_route(nh, nll);
+		}
+
+		memset(buf, 0, sizeof(buf));
+		if (poll(&fds_arp, 1, 3) == POLL_IN) {
+			nll = recv_msg(la, sock_arp);
+			if (nll < 0) {
+				fprintf(stderr, "recv from netlink: %s\n",
+					strerror(nll));
+				goto cleanup;
+			}
+
+			nh = (struct nlmsghdr *)buf;
+			read_arp(nh, nll);
+		}
+
+		sleep(interval);
+	}
+
+cleanup:
+	close(sock_arp);
+	close(sock);
+	return NULL;
+}
+
+static void usage(char *argv[], const struct option *long_options,
+		  const char *doc, int mask, bool error,
+		  struct bpf_object *obj)
+{
+	sample_usage(argv, long_options, doc, mask, error);
+}
+
+int main(int argc, char **argv)
+{
+	bool error = true, generic = false, force = false;
+	int opt, ret = EXIT_FAIL_BPF;
+	struct xdp_router_ipv4 *skel;
+	int i, total_ifindex = argc - 1;
+	char **ifname_list = argv + 1;
+	pthread_t routes_thread;
+	int longindex = 0;
+
+	if (libbpf_set_strict_mode(LIBBPF_STRICT_ALL) < 0) {
+		fprintf(stderr, "Failed to set libbpf strict mode: %s\n",
+			strerror(errno));
+		goto end;
+	}
+
+	skel = xdp_router_ipv4__open();
+	if (!skel) {
+		fprintf(stderr, "Failed to xdp_router_ipv4__open: %s\n",
+			strerror(errno));
+		goto end;
+	}
+
+	ret = sample_init_pre_load(skel);
+	if (ret < 0) {
+		fprintf(stderr, "Failed to sample_init_pre_load: %s\n",
+			strerror(-ret));
+		ret = EXIT_FAIL_BPF;
+		goto end_destroy;
+	}
+
+	ret = xdp_router_ipv4__load(skel);
+	if (ret < 0) {
+		fprintf(stderr, "Failed to xdp_router_ipv4__load: %s\n",
+			strerror(errno));
+		goto end_destroy;
+	}
+
+	ret = sample_init(skel, mask);
+	if (ret < 0) {
+		fprintf(stderr, "Failed to initialize sample: %s\n", strerror(-ret));
+		ret = EXIT_FAIL;
+		goto end_destroy;
+	}
+
+	while ((opt = getopt_long(argc, argv, "si:SFvh",
+				  long_options, &longindex)) != -1) {
+		switch (opt) {
+		case 's':
+			mask |= SAMPLE_REDIRECT_MAP_CNT;
+			total_ifindex--;
+			ifname_list++;
+			break;
+		case 'i':
+			interval = strtoul(optarg, NULL, 0);
+			total_ifindex -= 2;
+			ifname_list += 2;
+			break;
+		case 'S':
+			generic = true;
+			total_ifindex--;
+			ifname_list++;
+			break;
+		case 'F':
+			force = true;
+			total_ifindex--;
+			ifname_list++;
+			break;
+		case 'v':
+			sample_switch_mode();
+			total_ifindex--;
+			ifname_list++;
+			break;
+		case 'h':
+			error = false;
+		default:
+			usage(argv, long_options, __doc__, mask, error, skel->obj);
+			goto end_destroy;
+		}
+	}
+
+	ret = EXIT_FAIL_OPTION;
+	if (optind == argc) {
+		usage(argv, long_options, __doc__, mask, true, skel->obj);
+		goto end_destroy;
+	}
+
+	lpm_map_fd = bpf_map__fd(skel->maps.lpm_map);
+	if (lpm_map_fd < 0) {
+		fprintf(stderr, "Failed loading lpm_map %s\n",
+			strerror(-lpm_map_fd));
+		goto end_destroy;
+	}
+	arp_table_map_fd = bpf_map__fd(skel->maps.arp_table);
+	if (arp_table_map_fd < 0) {
+		fprintf(stderr, "Failed loading arp_table_map_fd %s\n",
+			strerror(-arp_table_map_fd));
+		goto end_destroy;
+	}
+	exact_match_map_fd = bpf_map__fd(skel->maps.exact_match);
+	if (exact_match_map_fd < 0) {
+		fprintf(stderr, "Failed loading exact_match_map_fd %s\n",
+			strerror(-exact_match_map_fd));
+		goto end_destroy;
+	}
+	tx_port_map_fd = bpf_map__fd(skel->maps.tx_port);
+	if (tx_port_map_fd < 0) {
+		fprintf(stderr, "Failed loading tx_port_map_fd %s\n",
+			strerror(-tx_port_map_fd));
+		goto end_destroy;
+	}
+
+	ret = EXIT_FAIL_XDP;
+	for (i = 0; i < total_ifindex; i++) {
+		int index = if_nametoindex(ifname_list[i]);
+
+		if (!index) {
+			fprintf(stderr, "Interface %s not found %s\n",
+				ifname_list[i], strerror(-tx_port_map_fd));
+			goto end_destroy;
+		}
+		if (sample_install_xdp(skel->progs.xdp_router_ipv4_prog,
+				       index, generic, force) < 0)
+			goto end_destroy;
+	}
+
+	ret = pthread_create(&routes_thread, NULL, monitor_routes_thread, NULL);
+	if (ret) {
+		fprintf(stderr, "Failed creating routes_thread: %s\n", strerror(-ret));
+		ret = EXIT_FAIL;
+		goto end_destroy;
+	}
+
+	ret = sample_run(interval, NULL, NULL);
+	routes_thread_exit = true;
+
+	if (ret < 0) {
+		fprintf(stderr, "Failed during sample run: %s\n", strerror(-ret));
+		ret = EXIT_FAIL;
+		goto end_thread_wait;
+	}
+	ret = EXIT_OK;
+
+end_thread_wait:
+	pthread_join(routes_thread, NULL);
+end_destroy:
+	xdp_router_ipv4__destroy(skel);
+end:
+	sample_exit(ret);
+}
diff --git a/samples/bpf/xdp_sample.bpf.c b/samples/bpf/xdp_sample.bpf.c
new file mode 100644
index 000000000..0eb7e1dca
--- /dev/null
+++ b/samples/bpf/xdp_sample.bpf.c
@@ -0,0 +1,266 @@
+// SPDX-License-Identifier: GPL-2.0
+/*  GPLv2, Copyright(c) 2017 Jesper Dangaard Brouer, Red Hat, Inc. */
+#include "xdp_sample.bpf.h"
+
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+#include <bpf/bpf_helpers.h>
+
+array_map rx_cnt SEC(".maps");
+array_map redir_err_cnt SEC(".maps");
+array_map cpumap_enqueue_cnt SEC(".maps");
+array_map cpumap_kthread_cnt SEC(".maps");
+array_map exception_cnt SEC(".maps");
+array_map devmap_xmit_cnt SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
+	__uint(max_entries, 32 * 32);
+	__type(key, u64);
+	__type(value, struct datarec);
+} devmap_xmit_cnt_multi SEC(".maps");
+
+const volatile int nr_cpus = 0;
+
+/* These can be set before loading so that redundant comparisons can be DCE'd by
+ * the verifier, and only actual matches are tried after loading tp_btf program.
+ * This allows sample to filter tracepoint stats based on net_device.
+ */
+const volatile int from_match[32] = {};
+const volatile int to_match[32] = {};
+
+int cpumap_map_id = 0;
+
+/* Find if b is part of set a, but if a is empty set then evaluate to true */
+#define IN_SET(a, b)                                                 \
+	({                                                           \
+		bool __res = !(a)[0];                                \
+		for (int i = 0; i < ARRAY_SIZE(a) && (a)[i]; i++) { \
+			__res = (a)[i] == (b);                       \
+			if (__res)                                   \
+				break;                               \
+		}                                                    \
+		__res;                                               \
+	})
+
+static __always_inline __u32 xdp_get_err_key(int err)
+{
+	switch (err) {
+	case 0:
+		return 0;
+	case -EINVAL:
+		return 2;
+	case -ENETDOWN:
+		return 3;
+	case -EMSGSIZE:
+		return 4;
+	case -EOPNOTSUPP:
+		return 5;
+	case -ENOSPC:
+		return 6;
+	default:
+		return 1;
+	}
+}
+
+static __always_inline int xdp_redirect_collect_stat(int from, int err)
+{
+	u32 cpu = bpf_get_smp_processor_id();
+	u32 key = XDP_REDIRECT_ERROR;
+	struct datarec *rec;
+	u32 idx;
+
+	if (!IN_SET(from_match, from))
+		return 0;
+
+	key = xdp_get_err_key(err);
+
+	idx = key * nr_cpus + cpu;
+	rec = bpf_map_lookup_elem(&redir_err_cnt, &idx);
+	if (!rec)
+		return 0;
+	if (key)
+		NO_TEAR_INC(rec->dropped);
+	else
+		NO_TEAR_INC(rec->processed);
+	return 0; /* Indicate event was filtered (no further processing)*/
+	/*
+	 * Returning 1 here would allow e.g. a perf-record tracepoint
+	 * to see and record these events, but it doesn't work well
+	 * in-practice as stopping perf-record also unload this
+	 * bpf_prog.  Plus, there is additional overhead of doing so.
+	 */
+}
+
+SEC("tp_btf/xdp_redirect_err")
+int BPF_PROG(tp_xdp_redirect_err, const struct net_device *dev,
+	     const struct bpf_prog *xdp, const void *tgt, int err,
+	     const struct bpf_map *map, u32 index)
+{
+	return xdp_redirect_collect_stat(dev->ifindex, err);
+}
+
+SEC("tp_btf/xdp_redirect_map_err")
+int BPF_PROG(tp_xdp_redirect_map_err, const struct net_device *dev,
+	     const struct bpf_prog *xdp, const void *tgt, int err,
+	     const struct bpf_map *map, u32 index)
+{
+	return xdp_redirect_collect_stat(dev->ifindex, err);
+}
+
+SEC("tp_btf/xdp_redirect")
+int BPF_PROG(tp_xdp_redirect, const struct net_device *dev,
+	     const struct bpf_prog *xdp, const void *tgt, int err,
+	     const struct bpf_map *map, u32 index)
+{
+	return xdp_redirect_collect_stat(dev->ifindex, err);
+}
+
+SEC("tp_btf/xdp_redirect_map")
+int BPF_PROG(tp_xdp_redirect_map, const struct net_device *dev,
+	     const struct bpf_prog *xdp, const void *tgt, int err,
+	     const struct bpf_map *map, u32 index)
+{
+	return xdp_redirect_collect_stat(dev->ifindex, err);
+}
+
+SEC("tp_btf/xdp_cpumap_enqueue")
+int BPF_PROG(tp_xdp_cpumap_enqueue, int map_id, unsigned int processed,
+	     unsigned int drops, int to_cpu)
+{
+	u32 cpu = bpf_get_smp_processor_id();
+	struct datarec *rec;
+	u32 idx;
+
+	if (cpumap_map_id && cpumap_map_id != map_id)
+		return 0;
+
+	idx = to_cpu * nr_cpus + cpu;
+	rec = bpf_map_lookup_elem(&cpumap_enqueue_cnt, &idx);
+	if (!rec)
+		return 0;
+	NO_TEAR_ADD(rec->processed, processed);
+	NO_TEAR_ADD(rec->dropped, drops);
+	/* Record bulk events, then userspace can calc average bulk size */
+	if (processed > 0)
+		NO_TEAR_INC(rec->issue);
+	/* Inception: It's possible to detect overload situations, via
+	 * this tracepoint.  This can be used for creating a feedback
+	 * loop to XDP, which can take appropriate actions to mitigate
+	 * this overload situation.
+	 */
+	return 0;
+}
+
+SEC("tp_btf/xdp_cpumap_kthread")
+int BPF_PROG(tp_xdp_cpumap_kthread, int map_id, unsigned int processed,
+	     unsigned int drops, int sched, struct xdp_cpumap_stats *xdp_stats)
+{
+	struct datarec *rec;
+	u32 cpu;
+
+	if (cpumap_map_id && cpumap_map_id != map_id)
+		return 0;
+
+	cpu = bpf_get_smp_processor_id();
+	rec = bpf_map_lookup_elem(&cpumap_kthread_cnt, &cpu);
+	if (!rec)
+		return 0;
+	NO_TEAR_ADD(rec->processed, processed);
+	NO_TEAR_ADD(rec->dropped, drops);
+	NO_TEAR_ADD(rec->xdp_pass, xdp_stats->pass);
+	NO_TEAR_ADD(rec->xdp_drop, xdp_stats->drop);
+	NO_TEAR_ADD(rec->xdp_redirect, xdp_stats->redirect);
+	/* Count times kthread yielded CPU via schedule call */
+	if (sched)
+		NO_TEAR_INC(rec->issue);
+	return 0;
+}
+
+SEC("tp_btf/xdp_exception")
+int BPF_PROG(tp_xdp_exception, const struct net_device *dev,
+	     const struct bpf_prog *xdp, u32 act)
+{
+	u32 cpu = bpf_get_smp_processor_id();
+	struct datarec *rec;
+	u32 key = act, idx;
+
+	if (!IN_SET(from_match, dev->ifindex))
+		return 0;
+	if (!IN_SET(to_match, dev->ifindex))
+		return 0;
+
+	if (key > XDP_REDIRECT)
+		key = XDP_REDIRECT + 1;
+
+	idx = key * nr_cpus + cpu;
+	rec = bpf_map_lookup_elem(&exception_cnt, &idx);
+	if (!rec)
+		return 0;
+	NO_TEAR_INC(rec->dropped);
+
+	return 0;
+}
+
+SEC("tp_btf/xdp_devmap_xmit")
+int BPF_PROG(tp_xdp_devmap_xmit, const struct net_device *from_dev,
+	     const struct net_device *to_dev, int sent, int drops, int err)
+{
+	struct datarec *rec;
+	int idx_in, idx_out;
+	u32 cpu;
+
+	idx_in = from_dev->ifindex;
+	idx_out = to_dev->ifindex;
+
+	if (!IN_SET(from_match, idx_in))
+		return 0;
+	if (!IN_SET(to_match, idx_out))
+		return 0;
+
+	cpu = bpf_get_smp_processor_id();
+	rec = bpf_map_lookup_elem(&devmap_xmit_cnt, &cpu);
+	if (!rec)
+		return 0;
+	NO_TEAR_ADD(rec->processed, sent);
+	NO_TEAR_ADD(rec->dropped, drops);
+	/* Record bulk events, then userspace can calc average bulk size */
+	NO_TEAR_INC(rec->info);
+	/* Record error cases, where no frame were sent */
+	/* Catch API error of drv ndo_xdp_xmit sent more than count */
+	if (err || drops < 0)
+		NO_TEAR_INC(rec->issue);
+	return 0;
+}
+
+SEC("tp_btf/xdp_devmap_xmit")
+int BPF_PROG(tp_xdp_devmap_xmit_multi, const struct net_device *from_dev,
+	     const struct net_device *to_dev, int sent, int drops, int err)
+{
+	struct datarec empty = {};
+	struct datarec *rec;
+	int idx_in, idx_out;
+	u64 idx;
+
+	idx_in = from_dev->ifindex;
+	idx_out = to_dev->ifindex;
+	idx = idx_in;
+	idx = idx << 32 | idx_out;
+
+	if (!IN_SET(from_match, idx_in))
+		return 0;
+	if (!IN_SET(to_match, idx_out))
+		return 0;
+
+	bpf_map_update_elem(&devmap_xmit_cnt_multi, &idx, &empty, BPF_NOEXIST);
+	rec = bpf_map_lookup_elem(&devmap_xmit_cnt_multi, &idx);
+	if (!rec)
+		return 0;
+
+	NO_TEAR_ADD(rec->processed, sent);
+	NO_TEAR_ADD(rec->dropped, drops);
+	NO_TEAR_INC(rec->info);
+	if (err || drops < 0)
+		NO_TEAR_INC(rec->issue);
+	return 0;
+}
diff --git a/samples/bpf/xdp_sample.bpf.h b/samples/bpf/xdp_sample.bpf.h
new file mode 100644
index 000000000..fecc41c5d
--- /dev/null
+++ b/samples/bpf/xdp_sample.bpf.h
@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef _XDP_SAMPLE_BPF_H
+#define _XDP_SAMPLE_BPF_H
+
+#include "vmlinux.h"
+#include <bpf/bpf_tracing.h>
+#include <bpf/bpf_core_read.h>
+#include <bpf/bpf_helpers.h>
+
+#include "net_shared.h"
+#include "xdp_sample_shared.h"
+
+#define EINVAL 22
+#define ENETDOWN 100
+#define EMSGSIZE 90
+#define EOPNOTSUPP 95
+#define ENOSPC 28
+
+typedef struct {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__uint(map_flags, BPF_F_MMAPABLE);
+	__type(key, unsigned int);
+	__type(value, struct datarec);
+} array_map;
+
+extern array_map rx_cnt;
+extern const volatile int nr_cpus;
+
+enum {
+	XDP_REDIRECT_SUCCESS = 0,
+	XDP_REDIRECT_ERROR = 1
+};
+
+static __always_inline void swap_src_dst_mac(void *data)
+{
+	unsigned short *p = data;
+	unsigned short dst[3];
+
+	dst[0] = p[0];
+	dst[1] = p[1];
+	dst[2] = p[2];
+	p[0] = p[3];
+	p[1] = p[4];
+	p[2] = p[5];
+	p[3] = dst[0];
+	p[4] = dst[1];
+	p[5] = dst[2];
+}
+
+/*
+ * Note: including linux/compiler.h or linux/kernel.h for the macros below
+ * conflicts with vmlinux.h include in BPF files, so we define them here.
+ *
+ * Following functions are taken from kernel sources and
+ * break aliasing rules in their original form.
+ *
+ * While kernel is compiled with -fno-strict-aliasing,
+ * perf uses -Wstrict-aliasing=3 which makes build fail
+ * under gcc 4.4.
+ *
+ * Using extra __may_alias__ type to allow aliasing
+ * in this case.
+ */
+typedef __u8  __attribute__((__may_alias__))  __u8_alias_t;
+typedef __u16 __attribute__((__may_alias__)) __u16_alias_t;
+typedef __u32 __attribute__((__may_alias__)) __u32_alias_t;
+typedef __u64 __attribute__((__may_alias__)) __u64_alias_t;
+
+static __always_inline void __read_once_size(const volatile void *p, void *res, int size)
+{
+	switch (size) {
+	case 1: *(__u8_alias_t  *) res = *(volatile __u8_alias_t  *) p; break;
+	case 2: *(__u16_alias_t *) res = *(volatile __u16_alias_t *) p; break;
+	case 4: *(__u32_alias_t *) res = *(volatile __u32_alias_t *) p; break;
+	case 8: *(__u64_alias_t *) res = *(volatile __u64_alias_t *) p; break;
+	default:
+		asm volatile ("" : : : "memory");
+		__builtin_memcpy((void *)res, (const void *)p, size);
+		asm volatile ("" : : : "memory");
+	}
+}
+
+static __always_inline void __write_once_size(volatile void *p, void *res, int size)
+{
+	switch (size) {
+	case 1: *(volatile  __u8_alias_t *) p = *(__u8_alias_t  *) res; break;
+	case 2: *(volatile __u16_alias_t *) p = *(__u16_alias_t *) res; break;
+	case 4: *(volatile __u32_alias_t *) p = *(__u32_alias_t *) res; break;
+	case 8: *(volatile __u64_alias_t *) p = *(__u64_alias_t *) res; break;
+	default:
+		asm volatile ("" : : : "memory");
+		__builtin_memcpy((void *)p, (const void *)res, size);
+		asm volatile ("" : : : "memory");
+	}
+}
+
+#define READ_ONCE(x)					\
+({							\
+	union { typeof(x) __val; char __c[1]; } __u =	\
+		{ .__c = { 0 } };			\
+	__read_once_size(&(x), __u.__c, sizeof(x));	\
+	__u.__val;					\
+})
+
+#define WRITE_ONCE(x, val)				\
+({							\
+	union { typeof(x) __val; char __c[1]; } __u =	\
+		{ .__val = (val) }; 			\
+	__write_once_size(&(x), __u.__c, sizeof(x));	\
+	__u.__val;					\
+})
+
+/* Add a value using relaxed read and relaxed write. Less expensive than
+ * fetch_add when there is no write concurrency.
+ */
+#define NO_TEAR_ADD(x, val) WRITE_ONCE((x), READ_ONCE(x) + (val))
+#define NO_TEAR_INC(x) NO_TEAR_ADD((x), 1)
+
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+
+#endif
diff --git a/samples/bpf/xdp_sample_shared.h b/samples/bpf/xdp_sample_shared.h
new file mode 100644
index 000000000..8a7669a5d
--- /dev/null
+++ b/samples/bpf/xdp_sample_shared.h
@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#ifndef _XDP_SAMPLE_SHARED_H
+#define _XDP_SAMPLE_SHARED_H
+
+struct datarec {
+	size_t processed;
+	size_t dropped;
+	size_t issue;
+	union {
+		size_t xdp_pass;
+		size_t info;
+	};
+	size_t xdp_drop;
+	size_t xdp_redirect;
+} __attribute__((aligned(64)));
+
+#endif
diff --git a/samples/bpf/xdp_sample_user.c b/samples/bpf/xdp_sample_user.c
new file mode 100644
index 000000000..158682852
--- /dev/null
+++ b/samples/bpf/xdp_sample_user.c
@@ -0,0 +1,1673 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#define _GNU_SOURCE
+
+#include <arpa/inet.h>
+#include <bpf/bpf.h>
+#include <bpf/libbpf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <linux/ethtool.h>
+#include <linux/hashtable.h>
+#include <linux/if_link.h>
+#include <linux/jhash.h>
+#include <linux/limits.h>
+#include <linux/list.h>
+#include <linux/sockios.h>
+#include <locale.h>
+#include <math.h>
+#include <net/if.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/signalfd.h>
+#include <sys/sysinfo.h>
+#include <sys/timerfd.h>
+#include <sys/utsname.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "bpf_util.h"
+#include "xdp_sample_user.h"
+
+#define __sample_print(fmt, cond, ...)                                         \
+	({                                                                     \
+		if (cond)                                                      \
+			printf(fmt, ##__VA_ARGS__);                            \
+	})
+
+#define print_always(fmt, ...) __sample_print(fmt, 1, ##__VA_ARGS__)
+#define print_default(fmt, ...)                                                \
+	__sample_print(fmt, sample_log_level & LL_DEFAULT, ##__VA_ARGS__)
+#define __print_err(err, fmt, ...)                                             \
+	({                                                                     \
+		__sample_print(fmt, err > 0 || sample_log_level & LL_DEFAULT,  \
+			       ##__VA_ARGS__);                                 \
+		sample_err_exp = sample_err_exp ? true : err > 0;              \
+	})
+#define print_err(err, fmt, ...) __print_err(err, fmt, ##__VA_ARGS__)
+
+#define __COLUMN(x) "%'10" x " %-13s"
+#define FMT_COLUMNf __COLUMN(".0f")
+#define FMT_COLUMNd __COLUMN("d")
+#define FMT_COLUMNl __COLUMN("llu")
+#define RX(rx) rx, "rx/s"
+#define PPS(pps) pps, "pkt/s"
+#define DROP(drop) drop, "drop/s"
+#define ERR(err) err, "error/s"
+#define HITS(hits) hits, "hit/s"
+#define XMIT(xmit) xmit, "xmit/s"
+#define PASS(pass) pass, "pass/s"
+#define REDIR(redir) redir, "redir/s"
+#define NANOSEC_PER_SEC 1000000000 /* 10^9 */
+
+#define XDP_UNKNOWN (XDP_REDIRECT + 1)
+#define XDP_ACTION_MAX (XDP_UNKNOWN + 1)
+#define XDP_REDIRECT_ERR_MAX 7
+
+enum map_type {
+	MAP_RX,
+	MAP_REDIRECT_ERR,
+	MAP_CPUMAP_ENQUEUE,
+	MAP_CPUMAP_KTHREAD,
+	MAP_EXCEPTION,
+	MAP_DEVMAP_XMIT,
+	MAP_DEVMAP_XMIT_MULTI,
+	NUM_MAP,
+};
+
+enum log_level {
+	LL_DEFAULT = 1U << 0,
+	LL_SIMPLE = 1U << 1,
+	LL_DEBUG = 1U << 2,
+};
+
+struct record {
+	__u64 timestamp;
+	struct datarec total;
+	struct datarec *cpu;
+};
+
+struct map_entry {
+	struct hlist_node node;
+	__u64 pair;
+	struct record val;
+};
+
+struct stats_record {
+	struct record rx_cnt;
+	struct record redir_err[XDP_REDIRECT_ERR_MAX];
+	struct record kthread;
+	struct record exception[XDP_ACTION_MAX];
+	struct record devmap_xmit;
+	DECLARE_HASHTABLE(xmit_map, 5);
+	struct record enq[];
+};
+
+struct sample_output {
+	struct {
+		__u64 rx;
+		__u64 redir;
+		__u64 drop;
+		__u64 drop_xmit;
+		__u64 err;
+		__u64 xmit;
+	} totals;
+	struct {
+		union {
+			__u64 pps;
+			__u64 num;
+		};
+		__u64 drop;
+		__u64 err;
+	} rx_cnt;
+	struct {
+		__u64 suc;
+		__u64 err;
+	} redir_cnt;
+	struct {
+		__u64 hits;
+	} except_cnt;
+	struct {
+		__u64 pps;
+		__u64 drop;
+		__u64 err;
+		double bavg;
+	} xmit_cnt;
+};
+
+struct xdp_desc {
+	int ifindex;
+	__u32 prog_id;
+	int flags;
+} sample_xdp_progs[32];
+
+struct datarec *sample_mmap[NUM_MAP];
+struct bpf_map *sample_map[NUM_MAP];
+size_t sample_map_count[NUM_MAP];
+enum log_level sample_log_level;
+struct sample_output sample_out;
+unsigned long sample_interval;
+bool sample_err_exp;
+int sample_xdp_cnt;
+int sample_n_cpus;
+int sample_sig_fd;
+int sample_mask;
+
+static const char *xdp_redirect_err_names[XDP_REDIRECT_ERR_MAX] = {
+	/* Key=1 keeps unknown errors */
+	"Success",
+	"Unknown",
+	"EINVAL",
+	"ENETDOWN",
+	"EMSGSIZE",
+	"EOPNOTSUPP",
+	"ENOSPC",
+};
+
+/* Keyed from Unknown */
+static const char *xdp_redirect_err_help[XDP_REDIRECT_ERR_MAX - 1] = {
+	"Unknown error",
+	"Invalid redirection",
+	"Device being redirected to is down",
+	"Packet length too large for device",
+	"Operation not supported",
+	"No space in ptr_ring of cpumap kthread",
+};
+
+static const char *xdp_action_names[XDP_ACTION_MAX] = {
+	[XDP_ABORTED]  = "XDP_ABORTED",
+	[XDP_DROP]     = "XDP_DROP",
+	[XDP_PASS]     = "XDP_PASS",
+	[XDP_TX]       = "XDP_TX",
+	[XDP_REDIRECT] = "XDP_REDIRECT",
+	[XDP_UNKNOWN]  = "XDP_UNKNOWN",
+};
+
+static __u64 gettime(void)
+{
+	struct timespec t;
+	int res;
+
+	res = clock_gettime(CLOCK_MONOTONIC, &t);
+	if (res < 0) {
+		fprintf(stderr, "Error with gettimeofday! (%i)\n", res);
+		return UINT64_MAX;
+	}
+	return (__u64)t.tv_sec * NANOSEC_PER_SEC + t.tv_nsec;
+}
+
+static const char *action2str(int action)
+{
+	if (action < XDP_ACTION_MAX)
+		return xdp_action_names[action];
+	return NULL;
+}
+
+static void sample_print_help(int mask)
+{
+	printf("Output format description\n\n"
+	       "By default, redirect success statistics are disabled, use -s to enable.\n"
+	       "The terse output mode is default, verbose mode can be activated using -v\n"
+	       "Use SIGQUIT (Ctrl + \\) to switch the mode dynamically at runtime\n\n"
+	       "Terse mode displays at most the following fields:\n"
+	       "  rx/s        Number of packets received per second\n"
+	       "  redir/s     Number of packets successfully redirected per second\n"
+	       "  err,drop/s  Aggregated count of errors per second (including dropped packets)\n"
+	       "  xmit/s      Number of packets transmitted on the output device per second\n\n"
+	       "Output description for verbose mode:\n"
+	       "  FIELD                 DESCRIPTION\n");
+
+	if (mask & SAMPLE_RX_CNT) {
+		printf("  receive\t\tDisplays the number of packets received & errors encountered\n"
+		       " \t\t\tWhenever an error or packet drop occurs, details of per CPU error\n"
+		       " \t\t\tand drop statistics will be expanded inline in terse mode.\n"
+		       " \t\t\t\tpkt/s     - Packets received per second\n"
+		       " \t\t\t\tdrop/s    - Packets dropped per second\n"
+		       " \t\t\t\terror/s   - Errors encountered per second\n\n");
+	}
+	if (mask & (SAMPLE_REDIRECT_CNT | SAMPLE_REDIRECT_ERR_CNT)) {
+		printf("  redirect\t\tDisplays the number of packets successfully redirected\n"
+		       "  \t\t\tErrors encountered are expanded under redirect_err field\n"
+		       "  \t\t\tNote that passing -s to enable it has a per packet overhead\n"
+		       "  \t\t\t\tredir/s   - Packets redirected successfully per second\n\n"
+		       "  redirect_err\t\tDisplays the number of packets that failed redirection\n"
+		       "  \t\t\tThe errno is expanded under this field with per CPU count\n"
+		       "  \t\t\tThe recognized errors are:\n");
+
+		for (int i = 2; i < XDP_REDIRECT_ERR_MAX; i++)
+			printf("\t\t\t  %s: %s\n", xdp_redirect_err_names[i],
+			       xdp_redirect_err_help[i - 1]);
+
+		printf("  \n\t\t\t\terror/s   - Packets that failed redirection per second\n\n");
+	}
+
+	if (mask & SAMPLE_CPUMAP_ENQUEUE_CNT) {
+		printf("  enqueue to cpu N\tDisplays the number of packets enqueued to bulk queue of CPU N\n"
+		       "  \t\t\tExpands to cpu:FROM->N to display enqueue stats for each CPU enqueuing to CPU N\n"
+		       "  \t\t\tReceived packets can be associated with the CPU redirect program is enqueuing \n"
+		       "  \t\t\tpackets to.\n"
+		       "  \t\t\t\tpkt/s    - Packets enqueued per second from other CPU to CPU N\n"
+		       "  \t\t\t\tdrop/s   - Packets dropped when trying to enqueue to CPU N\n"
+		       "  \t\t\t\tbulk-avg - Average number of packets processed for each event\n\n");
+	}
+
+	if (mask & SAMPLE_CPUMAP_KTHREAD_CNT) {
+		printf("  kthread\t\tDisplays the number of packets processed in CPUMAP kthread for each CPU\n"
+		       "  \t\t\tPackets consumed from ptr_ring in kthread, and its xdp_stats (after calling \n"
+		       "  \t\t\tCPUMAP bpf prog) are expanded below this. xdp_stats are expanded as a total and\n"
+		       "  \t\t\tthen per-CPU to associate it to each CPU's pinned CPUMAP kthread.\n"
+		       "  \t\t\t\tpkt/s    - Packets consumed per second from ptr_ring\n"
+		       "  \t\t\t\tdrop/s   - Packets dropped per second in kthread\n"
+		       "  \t\t\t\tsched    - Number of times kthread called schedule()\n\n"
+		       "  \t\t\txdp_stats (also expands to per-CPU counts)\n"
+		       "  \t\t\t\tpass/s  - XDP_PASS count for CPUMAP program execution\n"
+		       "  \t\t\t\tdrop/s  - XDP_DROP count for CPUMAP program execution\n"
+		       "  \t\t\t\tredir/s - XDP_REDIRECT count for CPUMAP program execution\n\n");
+	}
+
+	if (mask & SAMPLE_EXCEPTION_CNT) {
+		printf("  xdp_exception\t\tDisplays xdp_exception tracepoint events\n"
+		       "  \t\t\tThis can occur due to internal driver errors, unrecognized\n"
+		       "  \t\t\tXDP actions and due to explicit user trigger by use of XDP_ABORTED\n"
+		       "  \t\t\tEach action is expanded below this field with its count\n"
+		       "  \t\t\t\thit/s     - Number of times the tracepoint was hit per second\n\n");
+	}
+
+	if (mask & SAMPLE_DEVMAP_XMIT_CNT) {
+		printf("  devmap_xmit\t\tDisplays devmap_xmit tracepoint events\n"
+		       "  \t\t\tThis tracepoint is invoked for successful transmissions on output\n"
+		       "  \t\t\tdevice but these statistics are not available for generic XDP mode,\n"
+		       "  \t\t\thence they will be omitted from the output when using SKB mode\n"
+		       "  \t\t\t\txmit/s    - Number of packets that were transmitted per second\n"
+		       "  \t\t\t\tdrop/s    - Number of packets that failed transmissions per second\n"
+		       "  \t\t\t\tdrv_err/s - Number of internal driver errors per second\n"
+		       "  \t\t\t\tbulk-avg  - Average number of packets processed for each event\n\n");
+	}
+}
+
+void sample_usage(char *argv[], const struct option *long_options,
+		  const char *doc, int mask, bool error)
+{
+	int i;
+
+	if (!error)
+		sample_print_help(mask);
+
+	printf("\n%s\nOption for %s:\n", doc, argv[0]);
+	for (i = 0; long_options[i].name != 0; i++) {
+		printf(" --%-15s", long_options[i].name);
+		if (long_options[i].flag != NULL)
+			printf(" flag (internal value: %d)",
+			       *long_options[i].flag);
+		else
+			printf("\t short-option: -%c", long_options[i].val);
+		printf("\n");
+	}
+	printf("\n");
+}
+
+static struct datarec *alloc_record_per_cpu(void)
+{
+	unsigned int nr_cpus = libbpf_num_possible_cpus();
+	struct datarec *array;
+
+	array = calloc(nr_cpus, sizeof(*array));
+	if (!array) {
+		fprintf(stderr, "Failed to allocate memory (nr_cpus: %u)\n",
+			nr_cpus);
+		return NULL;
+	}
+	return array;
+}
+
+static int map_entry_init(struct map_entry *e, __u64 pair)
+{
+	e->pair = pair;
+	INIT_HLIST_NODE(&e->node);
+	e->val.timestamp = gettime();
+	e->val.cpu = alloc_record_per_cpu();
+	if (!e->val.cpu)
+		return -ENOMEM;
+	return 0;
+}
+
+static void map_collect_percpu(struct datarec *values, struct record *rec)
+{
+	/* For percpu maps, userspace gets a value per possible CPU */
+	unsigned int nr_cpus = libbpf_num_possible_cpus();
+	__u64 sum_xdp_redirect = 0;
+	__u64 sum_processed = 0;
+	__u64 sum_xdp_pass = 0;
+	__u64 sum_xdp_drop = 0;
+	__u64 sum_dropped = 0;
+	__u64 sum_issue = 0;
+	int i;
+
+	/* Get time as close as possible to reading map contents */
+	rec->timestamp = gettime();
+
+	/* Record and sum values from each CPU */
+	for (i = 0; i < nr_cpus; i++) {
+		rec->cpu[i].processed = READ_ONCE(values[i].processed);
+		rec->cpu[i].dropped = READ_ONCE(values[i].dropped);
+		rec->cpu[i].issue = READ_ONCE(values[i].issue);
+		rec->cpu[i].xdp_pass = READ_ONCE(values[i].xdp_pass);
+		rec->cpu[i].xdp_drop = READ_ONCE(values[i].xdp_drop);
+		rec->cpu[i].xdp_redirect = READ_ONCE(values[i].xdp_redirect);
+
+		sum_processed += rec->cpu[i].processed;
+		sum_dropped += rec->cpu[i].dropped;
+		sum_issue += rec->cpu[i].issue;
+		sum_xdp_pass += rec->cpu[i].xdp_pass;
+		sum_xdp_drop += rec->cpu[i].xdp_drop;
+		sum_xdp_redirect += rec->cpu[i].xdp_redirect;
+	}
+
+	rec->total.processed = sum_processed;
+	rec->total.dropped = sum_dropped;
+	rec->total.issue = sum_issue;
+	rec->total.xdp_pass = sum_xdp_pass;
+	rec->total.xdp_drop = sum_xdp_drop;
+	rec->total.xdp_redirect = sum_xdp_redirect;
+}
+
+static int map_collect_percpu_devmap(int map_fd, struct stats_record *rec)
+{
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	__u32 batch, count = 32;
+	struct datarec *values;
+	bool init = false;
+	__u64 *keys;
+	int i, ret;
+
+	keys = calloc(count, sizeof(__u64));
+	if (!keys)
+		return -ENOMEM;
+	values = calloc(count * nr_cpus, sizeof(struct datarec));
+	if (!values) {
+		free(keys);
+		return -ENOMEM;
+	}
+
+	for (;;) {
+		bool exit = false;
+
+		ret = bpf_map_lookup_batch(map_fd, init ? &batch : NULL, &batch,
+					   keys, values, &count, NULL);
+		if (ret < 0 && errno != ENOENT)
+			break;
+		if (errno == ENOENT)
+			exit = true;
+
+		init = true;
+		for (i = 0; i < count; i++) {
+			struct map_entry *e, *x = NULL;
+			__u64 pair = keys[i];
+			struct datarec *arr;
+
+			arr = &values[i * nr_cpus];
+			hash_for_each_possible(rec->xmit_map, e, node, pair) {
+				if (e->pair == pair) {
+					x = e;
+					break;
+				}
+			}
+			if (!x) {
+				x = calloc(1, sizeof(*x));
+				if (!x)
+					goto cleanup;
+				if (map_entry_init(x, pair) < 0) {
+					free(x);
+					goto cleanup;
+				}
+				hash_add(rec->xmit_map, &x->node, pair);
+			}
+			map_collect_percpu(arr, &x->val);
+		}
+
+		if (exit)
+			break;
+		count = 32;
+	}
+
+	free(values);
+	free(keys);
+	return 0;
+cleanup:
+	free(values);
+	free(keys);
+	return -ENOMEM;
+}
+
+static struct stats_record *alloc_stats_record(void)
+{
+	struct stats_record *rec;
+	int i;
+
+	rec = calloc(1, sizeof(*rec) + sample_n_cpus * sizeof(struct record));
+	if (!rec) {
+		fprintf(stderr, "Failed to allocate memory\n");
+		return NULL;
+	}
+
+	if (sample_mask & SAMPLE_RX_CNT) {
+		rec->rx_cnt.cpu = alloc_record_per_cpu();
+		if (!rec->rx_cnt.cpu) {
+			fprintf(stderr,
+				"Failed to allocate rx_cnt per-CPU array\n");
+			goto end_rec;
+		}
+	}
+	if (sample_mask & (SAMPLE_REDIRECT_CNT | SAMPLE_REDIRECT_ERR_CNT)) {
+		for (i = 0; i < XDP_REDIRECT_ERR_MAX; i++) {
+			rec->redir_err[i].cpu = alloc_record_per_cpu();
+			if (!rec->redir_err[i].cpu) {
+				fprintf(stderr,
+					"Failed to allocate redir_err per-CPU array for "
+					"\"%s\" case\n",
+					xdp_redirect_err_names[i]);
+				while (i--)
+					free(rec->redir_err[i].cpu);
+				goto end_rx_cnt;
+			}
+		}
+	}
+	if (sample_mask & SAMPLE_CPUMAP_KTHREAD_CNT) {
+		rec->kthread.cpu = alloc_record_per_cpu();
+		if (!rec->kthread.cpu) {
+			fprintf(stderr,
+				"Failed to allocate kthread per-CPU array\n");
+			goto end_redir;
+		}
+	}
+	if (sample_mask & SAMPLE_EXCEPTION_CNT) {
+		for (i = 0; i < XDP_ACTION_MAX; i++) {
+			rec->exception[i].cpu = alloc_record_per_cpu();
+			if (!rec->exception[i].cpu) {
+				fprintf(stderr,
+					"Failed to allocate exception per-CPU array for "
+					"\"%s\" case\n",
+					action2str(i));
+				while (i--)
+					free(rec->exception[i].cpu);
+				goto end_kthread;
+			}
+		}
+	}
+	if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT) {
+		rec->devmap_xmit.cpu = alloc_record_per_cpu();
+		if (!rec->devmap_xmit.cpu) {
+			fprintf(stderr,
+				"Failed to allocate devmap_xmit per-CPU array\n");
+			goto end_exception;
+		}
+	}
+	if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI)
+		hash_init(rec->xmit_map);
+	if (sample_mask & SAMPLE_CPUMAP_ENQUEUE_CNT) {
+		for (i = 0; i < sample_n_cpus; i++) {
+			rec->enq[i].cpu = alloc_record_per_cpu();
+			if (!rec->enq[i].cpu) {
+				fprintf(stderr,
+					"Failed to allocate enqueue per-CPU array for "
+					"CPU %d\n",
+					i);
+				while (i--)
+					free(rec->enq[i].cpu);
+				goto end_devmap_xmit;
+			}
+		}
+	}
+
+	return rec;
+
+end_devmap_xmit:
+	free(rec->devmap_xmit.cpu);
+end_exception:
+	for (i = 0; i < XDP_ACTION_MAX; i++)
+		free(rec->exception[i].cpu);
+end_kthread:
+	free(rec->kthread.cpu);
+end_redir:
+	for (i = 0; i < XDP_REDIRECT_ERR_MAX; i++)
+		free(rec->redir_err[i].cpu);
+end_rx_cnt:
+	free(rec->rx_cnt.cpu);
+end_rec:
+	free(rec);
+	return NULL;
+}
+
+static void free_stats_record(struct stats_record *r)
+{
+	struct hlist_node *tmp;
+	struct map_entry *e;
+	int i;
+
+	for (i = 0; i < sample_n_cpus; i++)
+		free(r->enq[i].cpu);
+	hash_for_each_safe(r->xmit_map, i, tmp, e, node) {
+		hash_del(&e->node);
+		free(e->val.cpu);
+		free(e);
+	}
+	free(r->devmap_xmit.cpu);
+	for (i = 0; i < XDP_ACTION_MAX; i++)
+		free(r->exception[i].cpu);
+	free(r->kthread.cpu);
+	for (i = 0; i < XDP_REDIRECT_ERR_MAX; i++)
+		free(r->redir_err[i].cpu);
+	free(r->rx_cnt.cpu);
+	free(r);
+}
+
+static double calc_period(struct record *r, struct record *p)
+{
+	double period_ = 0;
+	__u64 period = 0;
+
+	period = r->timestamp - p->timestamp;
+	if (period > 0)
+		period_ = ((double)period / NANOSEC_PER_SEC);
+
+	return period_;
+}
+
+static double sample_round(double val)
+{
+	if (val - floor(val) < 0.5)
+		return floor(val);
+	return ceil(val);
+}
+
+static __u64 calc_pps(struct datarec *r, struct datarec *p, double period_)
+{
+	__u64 packets = 0;
+	__u64 pps = 0;
+
+	if (period_ > 0) {
+		packets = r->processed - p->processed;
+		pps = sample_round(packets / period_);
+	}
+	return pps;
+}
+
+static __u64 calc_drop_pps(struct datarec *r, struct datarec *p, double period_)
+{
+	__u64 packets = 0;
+	__u64 pps = 0;
+
+	if (period_ > 0) {
+		packets = r->dropped - p->dropped;
+		pps = sample_round(packets / period_);
+	}
+	return pps;
+}
+
+static __u64 calc_errs_pps(struct datarec *r, struct datarec *p, double period_)
+{
+	__u64 packets = 0;
+	__u64 pps = 0;
+
+	if (period_ > 0) {
+		packets = r->issue - p->issue;
+		pps = sample_round(packets / period_);
+	}
+	return pps;
+}
+
+static __u64 calc_info_pps(struct datarec *r, struct datarec *p, double period_)
+{
+	__u64 packets = 0;
+	__u64 pps = 0;
+
+	if (period_ > 0) {
+		packets = r->info - p->info;
+		pps = sample_round(packets / period_);
+	}
+	return pps;
+}
+
+static void calc_xdp_pps(struct datarec *r, struct datarec *p, double *xdp_pass,
+			 double *xdp_drop, double *xdp_redirect, double period_)
+{
+	*xdp_pass = 0, *xdp_drop = 0, *xdp_redirect = 0;
+	if (period_ > 0) {
+		*xdp_redirect = (r->xdp_redirect - p->xdp_redirect) / period_;
+		*xdp_pass = (r->xdp_pass - p->xdp_pass) / period_;
+		*xdp_drop = (r->xdp_drop - p->xdp_drop) / period_;
+	}
+}
+
+static void stats_get_rx_cnt(struct stats_record *stats_rec,
+			     struct stats_record *stats_prev,
+			     unsigned int nr_cpus, struct sample_output *out)
+{
+	struct record *rec, *prev;
+	double t, pps, drop, err;
+	int i;
+
+	rec = &stats_rec->rx_cnt;
+	prev = &stats_prev->rx_cnt;
+	t = calc_period(rec, prev);
+
+	for (i = 0; i < nr_cpus; i++) {
+		struct datarec *r = &rec->cpu[i];
+		struct datarec *p = &prev->cpu[i];
+		char str[64];
+
+		pps = calc_pps(r, p, t);
+		drop = calc_drop_pps(r, p, t);
+		err = calc_errs_pps(r, p, t);
+		if (!pps && !drop && !err)
+			continue;
+
+		snprintf(str, sizeof(str), "cpu:%d", i);
+		print_default("    %-18s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
+			      "\n",
+			      str, PPS(pps), DROP(drop), ERR(err));
+	}
+
+	if (out) {
+		pps = calc_pps(&rec->total, &prev->total, t);
+		drop = calc_drop_pps(&rec->total, &prev->total, t);
+		err = calc_errs_pps(&rec->total, &prev->total, t);
+
+		out->rx_cnt.pps = pps;
+		out->rx_cnt.drop = drop;
+		out->rx_cnt.err = err;
+		out->totals.rx += pps;
+		out->totals.drop += drop;
+		out->totals.err += err;
+	}
+}
+
+static void stats_get_cpumap_enqueue(struct stats_record *stats_rec,
+				     struct stats_record *stats_prev,
+				     unsigned int nr_cpus)
+{
+	struct record *rec, *prev;
+	double t, pps, drop, err;
+	int i, to_cpu;
+
+	/* cpumap enqueue stats */
+	for (to_cpu = 0; to_cpu < sample_n_cpus; to_cpu++) {
+		rec = &stats_rec->enq[to_cpu];
+		prev = &stats_prev->enq[to_cpu];
+		t = calc_period(rec, prev);
+
+		pps = calc_pps(&rec->total, &prev->total, t);
+		drop = calc_drop_pps(&rec->total, &prev->total, t);
+		err = calc_errs_pps(&rec->total, &prev->total, t);
+
+		if (pps > 0 || drop > 0) {
+			char str[64];
+
+			snprintf(str, sizeof(str), "enqueue to cpu %d", to_cpu);
+
+			if (err > 0)
+				err = pps / err; /* calc average bulk size */
+
+			print_err(drop,
+				  "  %-20s " FMT_COLUMNf FMT_COLUMNf __COLUMN(
+					  ".2f") "\n",
+				  str, PPS(pps), DROP(drop), err, "bulk-avg");
+		}
+
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+			char str[64];
+
+			pps = calc_pps(r, p, t);
+			drop = calc_drop_pps(r, p, t);
+			err = calc_errs_pps(r, p, t);
+			if (!pps && !drop && !err)
+				continue;
+
+			snprintf(str, sizeof(str), "cpu:%d->%d", i, to_cpu);
+			if (err > 0)
+				err = pps / err; /* calc average bulk size */
+			print_default(
+				"    %-18s " FMT_COLUMNf FMT_COLUMNf __COLUMN(
+					".2f") "\n",
+				str, PPS(pps), DROP(drop), err, "bulk-avg");
+		}
+	}
+}
+
+static void stats_get_cpumap_remote(struct stats_record *stats_rec,
+				    struct stats_record *stats_prev,
+				    unsigned int nr_cpus)
+{
+	double xdp_pass, xdp_drop, xdp_redirect;
+	struct record *rec, *prev;
+	double t;
+	int i;
+
+	rec = &stats_rec->kthread;
+	prev = &stats_prev->kthread;
+	t = calc_period(rec, prev);
+
+	calc_xdp_pps(&rec->total, &prev->total, &xdp_pass, &xdp_drop,
+		     &xdp_redirect, t);
+	if (xdp_pass || xdp_drop || xdp_redirect) {
+		print_err(xdp_drop,
+			  "    %-18s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf "\n",
+			  "xdp_stats", PASS(xdp_pass), DROP(xdp_drop),
+			  REDIR(xdp_redirect));
+	}
+
+	for (i = 0; i < nr_cpus; i++) {
+		struct datarec *r = &rec->cpu[i];
+		struct datarec *p = &prev->cpu[i];
+		char str[64];
+
+		calc_xdp_pps(r, p, &xdp_pass, &xdp_drop, &xdp_redirect, t);
+		if (!xdp_pass && !xdp_drop && !xdp_redirect)
+			continue;
+
+		snprintf(str, sizeof(str), "cpu:%d", i);
+		print_default("      %-16s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
+			      "\n",
+			      str, PASS(xdp_pass), DROP(xdp_drop),
+			      REDIR(xdp_redirect));
+	}
+}
+
+static void stats_get_cpumap_kthread(struct stats_record *stats_rec,
+				     struct stats_record *stats_prev,
+				     unsigned int nr_cpus)
+{
+	struct record *rec, *prev;
+	double t, pps, drop, err;
+	int i;
+
+	rec = &stats_rec->kthread;
+	prev = &stats_prev->kthread;
+	t = calc_period(rec, prev);
+
+	pps = calc_pps(&rec->total, &prev->total, t);
+	drop = calc_drop_pps(&rec->total, &prev->total, t);
+	err = calc_errs_pps(&rec->total, &prev->total, t);
+
+	print_err(drop, "  %-20s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf "\n",
+		  pps ? "kthread total" : "kthread", PPS(pps), DROP(drop), err,
+		  "sched");
+
+	for (i = 0; i < nr_cpus; i++) {
+		struct datarec *r = &rec->cpu[i];
+		struct datarec *p = &prev->cpu[i];
+		char str[64];
+
+		pps = calc_pps(r, p, t);
+		drop = calc_drop_pps(r, p, t);
+		err = calc_errs_pps(r, p, t);
+		if (!pps && !drop && !err)
+			continue;
+
+		snprintf(str, sizeof(str), "cpu:%d", i);
+		print_default("    %-18s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
+			      "\n",
+			      str, PPS(pps), DROP(drop), err, "sched");
+	}
+}
+
+static void stats_get_redirect_cnt(struct stats_record *stats_rec,
+				   struct stats_record *stats_prev,
+				   unsigned int nr_cpus,
+				   struct sample_output *out)
+{
+	struct record *rec, *prev;
+	double t, pps;
+	int i;
+
+	rec = &stats_rec->redir_err[0];
+	prev = &stats_prev->redir_err[0];
+	t = calc_period(rec, prev);
+	for (i = 0; i < nr_cpus; i++) {
+		struct datarec *r = &rec->cpu[i];
+		struct datarec *p = &prev->cpu[i];
+		char str[64];
+
+		pps = calc_pps(r, p, t);
+		if (!pps)
+			continue;
+
+		snprintf(str, sizeof(str), "cpu:%d", i);
+		print_default("    %-18s " FMT_COLUMNf "\n", str, REDIR(pps));
+	}
+
+	if (out) {
+		pps = calc_pps(&rec->total, &prev->total, t);
+		out->redir_cnt.suc = pps;
+		out->totals.redir += pps;
+	}
+}
+
+static void stats_get_redirect_err_cnt(struct stats_record *stats_rec,
+				       struct stats_record *stats_prev,
+				       unsigned int nr_cpus,
+				       struct sample_output *out)
+{
+	struct record *rec, *prev;
+	double t, drop, sum = 0;
+	int rec_i, i;
+
+	for (rec_i = 1; rec_i < XDP_REDIRECT_ERR_MAX; rec_i++) {
+		char str[64];
+
+		rec = &stats_rec->redir_err[rec_i];
+		prev = &stats_prev->redir_err[rec_i];
+		t = calc_period(rec, prev);
+
+		drop = calc_drop_pps(&rec->total, &prev->total, t);
+		if (drop > 0 && !out) {
+			snprintf(str, sizeof(str),
+				 sample_log_level & LL_DEFAULT ? "%s total" :
+								       "%s",
+				 xdp_redirect_err_names[rec_i]);
+			print_err(drop, "    %-18s " FMT_COLUMNf "\n", str,
+				  ERR(drop));
+		}
+
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *r = &rec->cpu[i];
+			struct datarec *p = &prev->cpu[i];
+			double drop;
+
+			drop = calc_drop_pps(r, p, t);
+			if (!drop)
+				continue;
+
+			snprintf(str, sizeof(str), "cpu:%d", i);
+			print_default("       %-16s" FMT_COLUMNf "\n", str,
+				      ERR(drop));
+		}
+
+		sum += drop;
+	}
+
+	if (out) {
+		out->redir_cnt.err = sum;
+		out->totals.err += sum;
+	}
+}
+
+static void stats_get_exception_cnt(struct stats_record *stats_rec,
+				    struct stats_record *stats_prev,
+				    unsigned int nr_cpus,
+				    struct sample_output *out)
+{
+	double t, drop, sum = 0;
+	struct record *rec, *prev;
+	int rec_i, i;
+
+	for (rec_i = 0; rec_i < XDP_ACTION_MAX; rec_i++) {
+		rec = &stats_rec->exception[rec_i];
+		prev = &stats_prev->exception[rec_i];
+		t = calc_period(rec, prev);
+
+		drop = calc_drop_pps(&rec->total, &prev->total, t);
+		/* Fold out errors after heading */
+		sum += drop;
+
+		if (drop > 0 && !out) {
+			print_always("    %-18s " FMT_COLUMNf "\n",
+				     action2str(rec_i), ERR(drop));
+
+			for (i = 0; i < nr_cpus; i++) {
+				struct datarec *r = &rec->cpu[i];
+				struct datarec *p = &prev->cpu[i];
+				char str[64];
+				double drop;
+
+				drop = calc_drop_pps(r, p, t);
+				if (!drop)
+					continue;
+
+				snprintf(str, sizeof(str), "cpu:%d", i);
+				print_default("       %-16s" FMT_COLUMNf "\n",
+					      str, ERR(drop));
+			}
+		}
+	}
+
+	if (out) {
+		out->except_cnt.hits = sum;
+		out->totals.err += sum;
+	}
+}
+
+static void stats_get_devmap_xmit(struct stats_record *stats_rec,
+				  struct stats_record *stats_prev,
+				  unsigned int nr_cpus,
+				  struct sample_output *out)
+{
+	double pps, drop, info, err;
+	struct record *rec, *prev;
+	double t;
+	int i;
+
+	rec = &stats_rec->devmap_xmit;
+	prev = &stats_prev->devmap_xmit;
+	t = calc_period(rec, prev);
+	for (i = 0; i < nr_cpus; i++) {
+		struct datarec *r = &rec->cpu[i];
+		struct datarec *p = &prev->cpu[i];
+		char str[64];
+
+		pps = calc_pps(r, p, t);
+		drop = calc_drop_pps(r, p, t);
+		err = calc_errs_pps(r, p, t);
+
+		if (!pps && !drop && !err)
+			continue;
+
+		snprintf(str, sizeof(str), "cpu:%d", i);
+		info = calc_info_pps(r, p, t);
+		if (info > 0)
+			info = (pps + drop) / info; /* calc avg bulk */
+		print_default("     %-18s" FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
+				      __COLUMN(".2f") "\n",
+			      str, XMIT(pps), DROP(drop), err, "drv_err/s",
+			      info, "bulk-avg");
+	}
+	if (out) {
+		pps = calc_pps(&rec->total, &prev->total, t);
+		drop = calc_drop_pps(&rec->total, &prev->total, t);
+		info = calc_info_pps(&rec->total, &prev->total, t);
+		if (info > 0)
+			info = (pps + drop) / info; /* calc avg bulk */
+		err = calc_errs_pps(&rec->total, &prev->total, t);
+
+		out->xmit_cnt.pps = pps;
+		out->xmit_cnt.drop = drop;
+		out->xmit_cnt.bavg = info;
+		out->xmit_cnt.err = err;
+		out->totals.xmit += pps;
+		out->totals.drop_xmit += drop;
+		out->totals.err += err;
+	}
+}
+
+static void stats_get_devmap_xmit_multi(struct stats_record *stats_rec,
+					struct stats_record *stats_prev,
+					unsigned int nr_cpus,
+					struct sample_output *out,
+					bool xmit_total)
+{
+	double pps, drop, info, err;
+	struct map_entry *entry;
+	struct record *r, *p;
+	double t;
+	int bkt;
+
+	hash_for_each(stats_rec->xmit_map, bkt, entry, node) {
+		struct map_entry *e, *x = NULL;
+		char ifname_from[IFNAMSIZ];
+		char ifname_to[IFNAMSIZ];
+		const char *fstr, *tstr;
+		unsigned long prev_time;
+		struct record beg = {};
+		__u32 from_idx, to_idx;
+		char str[128];
+		__u64 pair;
+		int i;
+
+		prev_time = sample_interval * NANOSEC_PER_SEC;
+
+		pair = entry->pair;
+		from_idx = pair >> 32;
+		to_idx = pair & 0xFFFFFFFF;
+
+		r = &entry->val;
+		beg.timestamp = r->timestamp - prev_time;
+
+		/* Find matching entry from stats_prev map */
+		hash_for_each_possible(stats_prev->xmit_map, e, node, pair) {
+			if (e->pair == pair) {
+				x = e;
+				break;
+			}
+		}
+		if (x)
+			p = &x->val;
+		else
+			p = &beg;
+		t = calc_period(r, p);
+		pps = calc_pps(&r->total, &p->total, t);
+		drop = calc_drop_pps(&r->total, &p->total, t);
+		info = calc_info_pps(&r->total, &p->total, t);
+		if (info > 0)
+			info = (pps + drop) / info; /* calc avg bulk */
+		err = calc_errs_pps(&r->total, &p->total, t);
+
+		if (out) {
+			/* We are responsible for filling out totals */
+			out->totals.xmit += pps;
+			out->totals.drop_xmit += drop;
+			out->totals.err += err;
+			continue;
+		}
+
+		fstr = tstr = NULL;
+		if (if_indextoname(from_idx, ifname_from))
+			fstr = ifname_from;
+		if (if_indextoname(to_idx, ifname_to))
+			tstr = ifname_to;
+
+		snprintf(str, sizeof(str), "xmit %s->%s", fstr ?: "?",
+			 tstr ?: "?");
+		/* Skip idle streams of redirection */
+		if (pps || drop || err) {
+			print_err(drop,
+				  "  %-20s " FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
+				  __COLUMN(".2f") "\n", str, XMIT(pps), DROP(drop),
+				  err, "drv_err/s", info, "bulk-avg");
+		}
+
+		for (i = 0; i < nr_cpus; i++) {
+			struct datarec *rc = &r->cpu[i];
+			struct datarec *pc, p_beg = {};
+			char str[64];
+
+			pc = p == &beg ? &p_beg : &p->cpu[i];
+
+			pps = calc_pps(rc, pc, t);
+			drop = calc_drop_pps(rc, pc, t);
+			err = calc_errs_pps(rc, pc, t);
+
+			if (!pps && !drop && !err)
+				continue;
+
+			snprintf(str, sizeof(str), "cpu:%d", i);
+			info = calc_info_pps(rc, pc, t);
+			if (info > 0)
+				info = (pps + drop) / info; /* calc avg bulk */
+
+			print_default("     %-18s" FMT_COLUMNf FMT_COLUMNf FMT_COLUMNf
+				      __COLUMN(".2f") "\n", str, XMIT(pps),
+				      DROP(drop), err, "drv_err/s", info, "bulk-avg");
+		}
+	}
+}
+
+static void stats_print(const char *prefix, int mask, struct stats_record *r,
+			struct stats_record *p, struct sample_output *out)
+{
+	int nr_cpus = libbpf_num_possible_cpus();
+	const char *str;
+
+	print_always("%-23s", prefix ?: "Summary");
+	if (mask & SAMPLE_RX_CNT)
+		print_always(FMT_COLUMNl, RX(out->totals.rx));
+	if (mask & SAMPLE_REDIRECT_CNT)
+		print_always(FMT_COLUMNl, REDIR(out->totals.redir));
+	printf(FMT_COLUMNl,
+	       out->totals.err + out->totals.drop + out->totals.drop_xmit,
+	       "err,drop/s");
+	if (mask & SAMPLE_DEVMAP_XMIT_CNT ||
+	    mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI)
+		printf(FMT_COLUMNl, XMIT(out->totals.xmit));
+	printf("\n");
+
+	if (mask & SAMPLE_RX_CNT) {
+		str = (sample_log_level & LL_DEFAULT) && out->rx_cnt.pps ?
+				    "receive total" :
+				    "receive";
+		print_err((out->rx_cnt.err || out->rx_cnt.drop),
+			  "  %-20s " FMT_COLUMNl FMT_COLUMNl FMT_COLUMNl "\n",
+			  str, PPS(out->rx_cnt.pps), DROP(out->rx_cnt.drop),
+			  ERR(out->rx_cnt.err));
+
+		stats_get_rx_cnt(r, p, nr_cpus, NULL);
+	}
+
+	if (mask & SAMPLE_CPUMAP_ENQUEUE_CNT)
+		stats_get_cpumap_enqueue(r, p, nr_cpus);
+
+	if (mask & SAMPLE_CPUMAP_KTHREAD_CNT) {
+		stats_get_cpumap_kthread(r, p, nr_cpus);
+		stats_get_cpumap_remote(r, p, nr_cpus);
+	}
+
+	if (mask & SAMPLE_REDIRECT_CNT) {
+		str = out->redir_cnt.suc ? "redirect total" : "redirect";
+		print_default("  %-20s " FMT_COLUMNl "\n", str,
+			      REDIR(out->redir_cnt.suc));
+
+		stats_get_redirect_cnt(r, p, nr_cpus, NULL);
+	}
+
+	if (mask & SAMPLE_REDIRECT_ERR_CNT) {
+		str = (sample_log_level & LL_DEFAULT) && out->redir_cnt.err ?
+				    "redirect_err total" :
+				    "redirect_err";
+		print_err(out->redir_cnt.err, "  %-20s " FMT_COLUMNl "\n", str,
+			  ERR(out->redir_cnt.err));
+
+		stats_get_redirect_err_cnt(r, p, nr_cpus, NULL);
+	}
+
+	if (mask & SAMPLE_EXCEPTION_CNT) {
+		str = out->except_cnt.hits ? "xdp_exception total" :
+						   "xdp_exception";
+
+		print_err(out->except_cnt.hits, "  %-20s " FMT_COLUMNl "\n", str,
+			  HITS(out->except_cnt.hits));
+
+		stats_get_exception_cnt(r, p, nr_cpus, NULL);
+	}
+
+	if (mask & SAMPLE_DEVMAP_XMIT_CNT) {
+		str = (sample_log_level & LL_DEFAULT) && out->xmit_cnt.pps ?
+				    "devmap_xmit total" :
+				    "devmap_xmit";
+
+		print_err(out->xmit_cnt.err || out->xmit_cnt.drop,
+			  "  %-20s " FMT_COLUMNl FMT_COLUMNl FMT_COLUMNl
+				  __COLUMN(".2f") "\n",
+			  str, XMIT(out->xmit_cnt.pps),
+			  DROP(out->xmit_cnt.drop), out->xmit_cnt.err,
+			  "drv_err/s", out->xmit_cnt.bavg, "bulk-avg");
+
+		stats_get_devmap_xmit(r, p, nr_cpus, NULL);
+	}
+
+	if (mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI)
+		stats_get_devmap_xmit_multi(r, p, nr_cpus, NULL,
+					    mask & SAMPLE_DEVMAP_XMIT_CNT);
+
+	if (sample_log_level & LL_DEFAULT ||
+	    ((sample_log_level & LL_SIMPLE) && sample_err_exp)) {
+		sample_err_exp = false;
+		printf("\n");
+	}
+}
+
+int sample_setup_maps(struct bpf_map **maps)
+{
+	sample_n_cpus = libbpf_num_possible_cpus();
+
+	for (int i = 0; i < MAP_DEVMAP_XMIT_MULTI; i++) {
+		sample_map[i] = maps[i];
+
+		switch (i) {
+		case MAP_RX:
+		case MAP_CPUMAP_KTHREAD:
+		case MAP_DEVMAP_XMIT:
+			sample_map_count[i] = sample_n_cpus;
+			break;
+		case MAP_REDIRECT_ERR:
+			sample_map_count[i] =
+				XDP_REDIRECT_ERR_MAX * sample_n_cpus;
+			break;
+		case MAP_EXCEPTION:
+			sample_map_count[i] = XDP_ACTION_MAX * sample_n_cpus;
+		case MAP_CPUMAP_ENQUEUE:
+			sample_map_count[i] = sample_n_cpus * sample_n_cpus;
+			break;
+		default:
+			return -EINVAL;
+		}
+		if (bpf_map__set_max_entries(sample_map[i], sample_map_count[i]) < 0)
+			return -errno;
+	}
+	sample_map[MAP_DEVMAP_XMIT_MULTI] = maps[MAP_DEVMAP_XMIT_MULTI];
+	return 0;
+}
+
+static int sample_setup_maps_mappings(void)
+{
+	for (int i = 0; i < MAP_DEVMAP_XMIT_MULTI; i++) {
+		size_t size = sample_map_count[i] * sizeof(struct datarec);
+
+		sample_mmap[i] = mmap(NULL, size, PROT_READ | PROT_WRITE,
+				      MAP_SHARED, bpf_map__fd(sample_map[i]), 0);
+		if (sample_mmap[i] == MAP_FAILED)
+			return -errno;
+	}
+	return 0;
+}
+
+int __sample_init(int mask)
+{
+	sigset_t st;
+
+	sigemptyset(&st);
+	sigaddset(&st, SIGQUIT);
+	sigaddset(&st, SIGINT);
+	sigaddset(&st, SIGTERM);
+
+	if (sigprocmask(SIG_BLOCK, &st, NULL) < 0)
+		return -errno;
+
+	sample_sig_fd = signalfd(-1, &st, SFD_CLOEXEC | SFD_NONBLOCK);
+	if (sample_sig_fd < 0)
+		return -errno;
+
+	sample_mask = mask;
+
+	return sample_setup_maps_mappings();
+}
+
+static int __sample_remove_xdp(int ifindex, __u32 prog_id, int xdp_flags)
+{
+	__u32 cur_prog_id = 0;
+	int ret;
+
+	if (prog_id) {
+		ret = bpf_xdp_query_id(ifindex, xdp_flags, &cur_prog_id);
+		if (ret < 0)
+			return -errno;
+
+		if (prog_id != cur_prog_id) {
+			print_always(
+				"Program on ifindex %d does not match installed "
+				"program, skipping unload\n",
+				ifindex);
+			return -ENOENT;
+		}
+	}
+
+	return bpf_xdp_detach(ifindex, xdp_flags, NULL);
+}
+
+int sample_install_xdp(struct bpf_program *xdp_prog, int ifindex, bool generic,
+		       bool force)
+{
+	int ret, xdp_flags = 0;
+	__u32 prog_id = 0;
+
+	if (sample_xdp_cnt == 32) {
+		fprintf(stderr,
+			"Total limit for installed XDP programs in a sample reached\n");
+		return -ENOTSUP;
+	}
+
+	xdp_flags |= !force ? XDP_FLAGS_UPDATE_IF_NOEXIST : 0;
+	xdp_flags |= generic ? XDP_FLAGS_SKB_MODE : XDP_FLAGS_DRV_MODE;
+	ret = bpf_xdp_attach(ifindex, bpf_program__fd(xdp_prog), xdp_flags, NULL);
+	if (ret < 0) {
+		ret = -errno;
+		fprintf(stderr,
+			"Failed to install program \"%s\" on ifindex %d, mode = %s, "
+			"force = %s: %s\n",
+			bpf_program__name(xdp_prog), ifindex,
+			generic ? "skb" : "native", force ? "true" : "false",
+			strerror(-ret));
+		return ret;
+	}
+
+	ret = bpf_xdp_query_id(ifindex, xdp_flags, &prog_id);
+	if (ret < 0) {
+		ret = -errno;
+		fprintf(stderr,
+			"Failed to get XDP program id for ifindex %d, removing program: %s\n",
+			ifindex, strerror(errno));
+		__sample_remove_xdp(ifindex, 0, xdp_flags);
+		return ret;
+	}
+	sample_xdp_progs[sample_xdp_cnt++] =
+		(struct xdp_desc){ ifindex, prog_id, xdp_flags };
+
+	return 0;
+}
+
+static void sample_summary_print(void)
+{
+	double num = sample_out.rx_cnt.num;
+
+	if (sample_out.totals.rx) {
+		double pkts = sample_out.totals.rx;
+
+		print_always("  Packets received    : %'-10llu\n",
+			     sample_out.totals.rx);
+		print_always("  Average packets/s   : %'-10.0f\n",
+			     sample_round(pkts / num));
+	}
+	if (sample_out.totals.redir) {
+		double pkts = sample_out.totals.redir;
+
+		print_always("  Packets redirected  : %'-10llu\n",
+			     sample_out.totals.redir);
+		print_always("  Average redir/s     : %'-10.0f\n",
+			     sample_round(pkts / num));
+	}
+	if (sample_out.totals.drop)
+		print_always("  Rx dropped          : %'-10llu\n",
+			     sample_out.totals.drop);
+	if (sample_out.totals.drop_xmit)
+		print_always("  Tx dropped          : %'-10llu\n",
+			     sample_out.totals.drop_xmit);
+	if (sample_out.totals.err)
+		print_always("  Errors recorded     : %'-10llu\n",
+			     sample_out.totals.err);
+	if (sample_out.totals.xmit) {
+		double pkts = sample_out.totals.xmit;
+
+		print_always("  Packets transmitted : %'-10llu\n",
+			     sample_out.totals.xmit);
+		print_always("  Average transmit/s  : %'-10.0f\n",
+			     sample_round(pkts / num));
+	}
+}
+
+void sample_exit(int status)
+{
+	size_t size;
+
+	for (int i = 0; i < NUM_MAP; i++) {
+		size = sample_map_count[i] * sizeof(**sample_mmap);
+		munmap(sample_mmap[i], size);
+	}
+	while (sample_xdp_cnt--) {
+		int i = sample_xdp_cnt, ifindex, xdp_flags;
+		__u32 prog_id;
+
+		prog_id = sample_xdp_progs[i].prog_id;
+		ifindex = sample_xdp_progs[i].ifindex;
+		xdp_flags = sample_xdp_progs[i].flags;
+
+		__sample_remove_xdp(ifindex, prog_id, xdp_flags);
+	}
+	sample_summary_print();
+	close(sample_sig_fd);
+	exit(status);
+}
+
+static int sample_stats_collect(struct stats_record *rec)
+{
+	int i;
+
+	if (sample_mask & SAMPLE_RX_CNT)
+		map_collect_percpu(sample_mmap[MAP_RX], &rec->rx_cnt);
+
+	if (sample_mask & SAMPLE_REDIRECT_CNT)
+		map_collect_percpu(sample_mmap[MAP_REDIRECT_ERR], &rec->redir_err[0]);
+
+	if (sample_mask & SAMPLE_REDIRECT_ERR_CNT) {
+		for (i = 1; i < XDP_REDIRECT_ERR_MAX; i++)
+			map_collect_percpu(&sample_mmap[MAP_REDIRECT_ERR][i * sample_n_cpus],
+					   &rec->redir_err[i]);
+	}
+
+	if (sample_mask & SAMPLE_CPUMAP_ENQUEUE_CNT)
+		for (i = 0; i < sample_n_cpus; i++)
+			map_collect_percpu(&sample_mmap[MAP_CPUMAP_ENQUEUE][i * sample_n_cpus],
+					   &rec->enq[i]);
+
+	if (sample_mask & SAMPLE_CPUMAP_KTHREAD_CNT)
+		map_collect_percpu(sample_mmap[MAP_CPUMAP_KTHREAD],
+				   &rec->kthread);
+
+	if (sample_mask & SAMPLE_EXCEPTION_CNT)
+		for (i = 0; i < XDP_ACTION_MAX; i++)
+			map_collect_percpu(&sample_mmap[MAP_EXCEPTION][i * sample_n_cpus],
+					   &rec->exception[i]);
+
+	if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT)
+		map_collect_percpu(sample_mmap[MAP_DEVMAP_XMIT], &rec->devmap_xmit);
+
+	if (sample_mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI) {
+		if (map_collect_percpu_devmap(bpf_map__fd(sample_map[MAP_DEVMAP_XMIT_MULTI]), rec) < 0)
+			return -EINVAL;
+	}
+	return 0;
+}
+
+static void sample_summary_update(struct sample_output *out)
+{
+	sample_out.totals.rx += out->totals.rx;
+	sample_out.totals.redir += out->totals.redir;
+	sample_out.totals.drop += out->totals.drop;
+	sample_out.totals.drop_xmit += out->totals.drop_xmit;
+	sample_out.totals.err += out->totals.err;
+	sample_out.totals.xmit += out->totals.xmit;
+	sample_out.rx_cnt.num++;
+}
+
+static void sample_stats_print(int mask, struct stats_record *cur,
+			       struct stats_record *prev, char *prog_name)
+{
+	struct sample_output out = {};
+
+	if (mask & SAMPLE_RX_CNT)
+		stats_get_rx_cnt(cur, prev, 0, &out);
+	if (mask & SAMPLE_REDIRECT_CNT)
+		stats_get_redirect_cnt(cur, prev, 0, &out);
+	if (mask & SAMPLE_REDIRECT_ERR_CNT)
+		stats_get_redirect_err_cnt(cur, prev, 0, &out);
+	if (mask & SAMPLE_EXCEPTION_CNT)
+		stats_get_exception_cnt(cur, prev, 0, &out);
+	if (mask & SAMPLE_DEVMAP_XMIT_CNT)
+		stats_get_devmap_xmit(cur, prev, 0, &out);
+	else if (mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI)
+		stats_get_devmap_xmit_multi(cur, prev, 0, &out,
+					    mask & SAMPLE_DEVMAP_XMIT_CNT);
+	sample_summary_update(&out);
+
+	stats_print(prog_name, mask, cur, prev, &out);
+}
+
+void sample_switch_mode(void)
+{
+	sample_log_level ^= LL_DEBUG - 1;
+}
+
+static int sample_signal_cb(void)
+{
+	struct signalfd_siginfo si;
+	int r;
+
+	r = read(sample_sig_fd, &si, sizeof(si));
+	if (r < 0)
+		return -errno;
+
+	switch (si.ssi_signo) {
+	case SIGQUIT:
+		sample_switch_mode();
+		printf("\n");
+		break;
+	default:
+		printf("\n");
+		return 1;
+	}
+
+	return 0;
+}
+
+/* Pointer swap trick */
+static void swap(struct stats_record **a, struct stats_record **b)
+{
+	struct stats_record *tmp;
+
+	tmp = *a;
+	*a = *b;
+	*b = tmp;
+}
+
+static int sample_timer_cb(int timerfd, struct stats_record **rec,
+			   struct stats_record **prev)
+{
+	char line[64] = "Summary";
+	int ret;
+	__u64 t;
+
+	ret = read(timerfd, &t, sizeof(t));
+	if (ret < 0)
+		return -errno;
+
+	swap(prev, rec);
+	ret = sample_stats_collect(*rec);
+	if (ret < 0)
+		return ret;
+
+	if (sample_xdp_cnt == 2 && !(sample_mask & SAMPLE_SKIP_HEADING)) {
+		char fi[IFNAMSIZ];
+		char to[IFNAMSIZ];
+		const char *f, *t;
+
+		f = t = NULL;
+		if (if_indextoname(sample_xdp_progs[0].ifindex, fi))
+			f = fi;
+		if (if_indextoname(sample_xdp_progs[1].ifindex, to))
+			t = to;
+
+		snprintf(line, sizeof(line), "%s->%s", f ?: "?", t ?: "?");
+	}
+
+	sample_stats_print(sample_mask, *rec, *prev, line);
+	return 0;
+}
+
+int sample_run(int interval, void (*post_cb)(void *), void *ctx)
+{
+	struct timespec ts = { interval, 0 };
+	struct itimerspec its = { ts, ts };
+	struct stats_record *rec, *prev;
+	struct pollfd pfd[2] = {};
+	int timerfd, ret;
+
+	if (!interval) {
+		fprintf(stderr, "Incorrect interval 0\n");
+		return -EINVAL;
+	}
+	sample_interval = interval;
+	/* Pretty print numbers */
+	setlocale(LC_NUMERIC, "en_US.UTF-8");
+
+	timerfd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC | TFD_NONBLOCK);
+	if (timerfd < 0)
+		return -errno;
+	timerfd_settime(timerfd, 0, &its, NULL);
+
+	pfd[0].fd = sample_sig_fd;
+	pfd[0].events = POLLIN;
+
+	pfd[1].fd = timerfd;
+	pfd[1].events = POLLIN;
+
+	ret = -ENOMEM;
+	rec = alloc_stats_record();
+	if (!rec)
+		goto end;
+	prev = alloc_stats_record();
+	if (!prev)
+		goto end_rec;
+
+	ret = sample_stats_collect(rec);
+	if (ret < 0)
+		goto end_rec_prev;
+
+	for (;;) {
+		ret = poll(pfd, 2, -1);
+		if (ret < 0) {
+			if (errno == EINTR)
+				continue;
+			else
+				break;
+		}
+
+		if (pfd[0].revents & POLLIN)
+			ret = sample_signal_cb();
+		else if (pfd[1].revents & POLLIN)
+			ret = sample_timer_cb(timerfd, &rec, &prev);
+
+		if (ret)
+			break;
+
+		if (post_cb)
+			post_cb(ctx);
+	}
+
+end_rec_prev:
+	free_stats_record(prev);
+end_rec:
+	free_stats_record(rec);
+end:
+	close(timerfd);
+
+	return ret;
+}
+
+const char *get_driver_name(int ifindex)
+{
+	struct ethtool_drvinfo drv = {};
+	char ifname[IF_NAMESIZE];
+	static char drvname[32];
+	struct ifreq ifr = {};
+	int fd, r = 0;
+
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (fd < 0)
+		return "[error]";
+
+	if (!if_indextoname(ifindex, ifname))
+		goto end;
+
+	drv.cmd = ETHTOOL_GDRVINFO;
+	safe_strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+	ifr.ifr_data = (void *)&drv;
+
+	r = ioctl(fd, SIOCETHTOOL, &ifr);
+	if (r)
+		goto end;
+
+	safe_strncpy(drvname, drv.driver, sizeof(drvname));
+
+	close(fd);
+	return drvname;
+
+end:
+	r = errno;
+	close(fd);
+	return r == EOPNOTSUPP ? "loopback" : "[error]";
+}
+
+int get_mac_addr(int ifindex, void *mac_addr)
+{
+	char ifname[IF_NAMESIZE];
+	struct ifreq ifr = {};
+	int fd, r;
+
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	if (fd < 0)
+		return -errno;
+
+	if (!if_indextoname(ifindex, ifname)) {
+		r = -errno;
+		goto end;
+	}
+
+	safe_strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+
+	r = ioctl(fd, SIOCGIFHWADDR, &ifr);
+	if (r) {
+		r = -errno;
+		goto end;
+	}
+
+	memcpy(mac_addr, ifr.ifr_hwaddr.sa_data, 6 * sizeof(char));
+
+end:
+	close(fd);
+	return r;
+}
+
+__attribute__((constructor)) static void sample_ctor(void)
+{
+	if (libbpf_set_strict_mode(LIBBPF_STRICT_ALL) < 0) {
+		fprintf(stderr, "Failed to set libbpf strict mode: %s\n",
+			strerror(errno));
+		/* Just exit, nothing to cleanup right now */
+		exit(EXIT_FAIL_BPF);
+	}
+}
diff --git a/samples/bpf/xdp_sample_user.h b/samples/bpf/xdp_sample_user.h
new file mode 100644
index 000000000..f45051679
--- /dev/null
+++ b/samples/bpf/xdp_sample_user.h
@@ -0,0 +1,110 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#ifndef XDP_SAMPLE_USER_H
+#define XDP_SAMPLE_USER_H
+
+#include <bpf/libbpf.h>
+#include <linux/compiler.h>
+
+#include "xdp_sample_shared.h"
+
+enum stats_mask {
+	_SAMPLE_REDIRECT_MAP         = 1U << 0,
+	SAMPLE_RX_CNT                = 1U << 1,
+	SAMPLE_REDIRECT_ERR_CNT      = 1U << 2,
+	SAMPLE_CPUMAP_ENQUEUE_CNT    = 1U << 3,
+	SAMPLE_CPUMAP_KTHREAD_CNT    = 1U << 4,
+	SAMPLE_EXCEPTION_CNT         = 1U << 5,
+	SAMPLE_DEVMAP_XMIT_CNT       = 1U << 6,
+	SAMPLE_REDIRECT_CNT          = 1U << 7,
+	SAMPLE_REDIRECT_MAP_CNT      = SAMPLE_REDIRECT_CNT | _SAMPLE_REDIRECT_MAP,
+	SAMPLE_REDIRECT_ERR_MAP_CNT  = SAMPLE_REDIRECT_ERR_CNT | _SAMPLE_REDIRECT_MAP,
+	SAMPLE_DEVMAP_XMIT_CNT_MULTI = 1U << 8,
+	SAMPLE_SKIP_HEADING	     = 1U << 9,
+};
+
+/* Exit return codes */
+#define EXIT_OK			0
+#define EXIT_FAIL		1
+#define EXIT_FAIL_OPTION	2
+#define EXIT_FAIL_XDP		3
+#define EXIT_FAIL_BPF		4
+#define EXIT_FAIL_MEM		5
+
+int sample_setup_maps(struct bpf_map **maps);
+int __sample_init(int mask);
+void sample_exit(int status);
+int sample_run(int interval, void (*post_cb)(void *), void *ctx);
+
+void sample_switch_mode(void);
+int sample_install_xdp(struct bpf_program *xdp_prog, int ifindex, bool generic,
+		       bool force);
+void sample_usage(char *argv[], const struct option *long_options,
+		  const char *doc, int mask, bool error);
+
+const char *get_driver_name(int ifindex);
+int get_mac_addr(int ifindex, void *mac_addr);
+
+#pragma GCC diagnostic push
+#ifndef __clang__
+#pragma GCC diagnostic ignored "-Wstringop-truncation"
+#endif
+__attribute__((unused))
+static inline char *safe_strncpy(char *dst, const char *src, size_t size)
+{
+	if (!size)
+		return dst;
+	strncpy(dst, src, size - 1);
+	dst[size - 1] = '\0';
+	return dst;
+}
+#pragma GCC diagnostic pop
+
+#define __attach_tp(name)                                                      \
+	({                                                                     \
+		if (bpf_program__type(skel->progs.name) != BPF_PROG_TYPE_TRACING)\
+			return -EINVAL;                                        \
+		skel->links.name = bpf_program__attach(skel->progs.name);      \
+		if (!skel->links.name)                                         \
+			return -errno;                                         \
+	})
+
+#define sample_init_pre_load(skel)                                             \
+	({                                                                     \
+		skel->rodata->nr_cpus = libbpf_num_possible_cpus();            \
+		sample_setup_maps((struct bpf_map *[]){                        \
+			skel->maps.rx_cnt, skel->maps.redir_err_cnt,           \
+			skel->maps.cpumap_enqueue_cnt,                         \
+			skel->maps.cpumap_kthread_cnt,                         \
+			skel->maps.exception_cnt, skel->maps.devmap_xmit_cnt,  \
+			skel->maps.devmap_xmit_cnt_multi });                   \
+	})
+
+#define DEFINE_SAMPLE_INIT(name)                                               \
+	static int sample_init(struct name *skel, int mask)                    \
+	{                                                                      \
+		int ret;                                                       \
+		ret = __sample_init(mask);                                     \
+		if (ret < 0)                                                   \
+			return ret;                                            \
+		if (mask & SAMPLE_REDIRECT_MAP_CNT)                            \
+			__attach_tp(tp_xdp_redirect_map);                      \
+		if (mask & SAMPLE_REDIRECT_CNT)                                \
+			__attach_tp(tp_xdp_redirect);                          \
+		if (mask & SAMPLE_REDIRECT_ERR_MAP_CNT)                        \
+			__attach_tp(tp_xdp_redirect_map_err);                  \
+		if (mask & SAMPLE_REDIRECT_ERR_CNT)                            \
+			__attach_tp(tp_xdp_redirect_err);                      \
+		if (mask & SAMPLE_CPUMAP_ENQUEUE_CNT)                          \
+			__attach_tp(tp_xdp_cpumap_enqueue);                    \
+		if (mask & SAMPLE_CPUMAP_KTHREAD_CNT)                          \
+			__attach_tp(tp_xdp_cpumap_kthread);                    \
+		if (mask & SAMPLE_EXCEPTION_CNT)                               \
+			__attach_tp(tp_xdp_exception);                         \
+		if (mask & SAMPLE_DEVMAP_XMIT_CNT)                             \
+			__attach_tp(tp_xdp_devmap_xmit);                       \
+		if (mask & SAMPLE_DEVMAP_XMIT_CNT_MULTI)                       \
+			__attach_tp(tp_xdp_devmap_xmit_multi);                 \
+		return 0;                                                      \
+	}
+
+#endif
diff --git a/samples/bpf/xdp_tx_iptunnel_common.h b/samples/bpf/xdp_tx_iptunnel_common.h
new file mode 100644
index 000000000..be839892c
--- /dev/null
+++ b/samples/bpf/xdp_tx_iptunnel_common.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2016 Facebook
+ */
+#ifndef _SAMPLES_BPF_XDP_TX_IPTNL_COMMON_H
+#define _SAMPLES_BPF_XDP_TX_IPTNL_COMMON_H
+
+#include <linux/types.h>
+
+#define MAX_IPTNL_ENTRIES 256U
+
+struct vip {
+	union {
+		__u32 v6[4];
+		__u32 v4;
+	} daddr;
+	__u16 dport;
+	__u16 family;
+	__u8 protocol;
+};
+
+struct iptnl_info {
+	union {
+		__u32 v6[4];
+		__u32 v4;
+	} saddr;
+	union {
+		__u32 v6[4];
+		__u32 v4;
+	} daddr;
+	__u16 family;
+	__u8 dmac[6];
+};
+
+#endif
diff --git a/samples/bpf/xdp_tx_iptunnel_kern.c b/samples/bpf/xdp_tx_iptunnel_kern.c
new file mode 100644
index 000000000..0e2bca3a3
--- /dev/null
+++ b/samples/bpf/xdp_tx_iptunnel_kern.c
@@ -0,0 +1,237 @@
+/* Copyright (c) 2016 Facebook
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ *
+ * This program shows how to use bpf_xdp_adjust_head() by
+ * encapsulating the incoming packet in an IPv4/v6 header
+ * and then XDP_TX it out.
+ */
+#define KBUILD_MODNAME "foo"
+#include <uapi/linux/bpf.h>
+#include <linux/in.h>
+#include <linux/if_ether.h>
+#include <linux/if_packet.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <bpf/bpf_helpers.h>
+#include "xdp_tx_iptunnel_common.h"
+
+struct {
+	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
+	__type(key, __u32);
+	__type(value, __u64);
+	__uint(max_entries, 256);
+} rxcnt SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, struct vip);
+	__type(value, struct iptnl_info);
+	__uint(max_entries, MAX_IPTNL_ENTRIES);
+} vip2tnl SEC(".maps");
+
+static __always_inline void count_tx(u32 protocol)
+{
+	u64 *rxcnt_count;
+
+	rxcnt_count = bpf_map_lookup_elem(&rxcnt, &protocol);
+	if (rxcnt_count)
+		*rxcnt_count += 1;
+}
+
+static __always_inline int get_dport(void *trans_data, void *data_end,
+				     u8 protocol)
+{
+	struct tcphdr *th;
+	struct udphdr *uh;
+
+	switch (protocol) {
+	case IPPROTO_TCP:
+		th = (struct tcphdr *)trans_data;
+		if (th + 1 > data_end)
+			return -1;
+		return th->dest;
+	case IPPROTO_UDP:
+		uh = (struct udphdr *)trans_data;
+		if (uh + 1 > data_end)
+			return -1;
+		return uh->dest;
+	default:
+		return 0;
+	}
+}
+
+static __always_inline void set_ethhdr(struct ethhdr *new_eth,
+				       const struct ethhdr *old_eth,
+				       const struct iptnl_info *tnl,
+				       __be16 h_proto)
+{
+	memcpy(new_eth->h_source, old_eth->h_dest, sizeof(new_eth->h_source));
+	memcpy(new_eth->h_dest, tnl->dmac, sizeof(new_eth->h_dest));
+	new_eth->h_proto = h_proto;
+}
+
+static __always_inline int handle_ipv4(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	struct iptnl_info *tnl;
+	struct ethhdr *new_eth;
+	struct ethhdr *old_eth;
+	struct iphdr *iph = data + sizeof(struct ethhdr);
+	u16 *next_iph_u16;
+	u16 payload_len;
+	struct vip vip = {};
+	int dport;
+	u32 csum = 0;
+	int i;
+
+	if (iph + 1 > data_end)
+		return XDP_DROP;
+
+	dport = get_dport(iph + 1, data_end, iph->protocol);
+	if (dport == -1)
+		return XDP_DROP;
+
+	vip.protocol = iph->protocol;
+	vip.family = AF_INET;
+	vip.daddr.v4 = iph->daddr;
+	vip.dport = dport;
+	payload_len = ntohs(iph->tot_len);
+
+	tnl = bpf_map_lookup_elem(&vip2tnl, &vip);
+	/* It only does v4-in-v4 */
+	if (!tnl || tnl->family != AF_INET)
+		return XDP_PASS;
+
+	/* The vip key is found.  Add an IP header and send it out */
+
+	if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct iphdr)))
+		return XDP_DROP;
+
+	data = (void *)(long)xdp->data;
+	data_end = (void *)(long)xdp->data_end;
+
+	new_eth = data;
+	iph = data + sizeof(*new_eth);
+	old_eth = data + sizeof(*iph);
+
+	if (new_eth + 1 > data_end ||
+	    old_eth + 1 > data_end ||
+	    iph + 1 > data_end)
+		return XDP_DROP;
+
+	set_ethhdr(new_eth, old_eth, tnl, htons(ETH_P_IP));
+
+	iph->version = 4;
+	iph->ihl = sizeof(*iph) >> 2;
+	iph->frag_off =	0;
+	iph->protocol = IPPROTO_IPIP;
+	iph->check = 0;
+	iph->tos = 0;
+	iph->tot_len = htons(payload_len + sizeof(*iph));
+	iph->daddr = tnl->daddr.v4;
+	iph->saddr = tnl->saddr.v4;
+	iph->ttl = 8;
+
+	next_iph_u16 = (u16 *)iph;
+#pragma clang loop unroll(full)
+	for (i = 0; i < sizeof(*iph) >> 1; i++)
+		csum += *next_iph_u16++;
+
+	iph->check = ~((csum & 0xffff) + (csum >> 16));
+
+	count_tx(vip.protocol);
+
+	return XDP_TX;
+}
+
+static __always_inline int handle_ipv6(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	struct iptnl_info *tnl;
+	struct ethhdr *new_eth;
+	struct ethhdr *old_eth;
+	struct ipv6hdr *ip6h = data + sizeof(struct ethhdr);
+	__u16 payload_len;
+	struct vip vip = {};
+	int dport;
+
+	if (ip6h + 1 > data_end)
+		return XDP_DROP;
+
+	dport = get_dport(ip6h + 1, data_end, ip6h->nexthdr);
+	if (dport == -1)
+		return XDP_DROP;
+
+	vip.protocol = ip6h->nexthdr;
+	vip.family = AF_INET6;
+	memcpy(vip.daddr.v6, ip6h->daddr.s6_addr32, sizeof(vip.daddr));
+	vip.dport = dport;
+	payload_len = ip6h->payload_len;
+
+	tnl = bpf_map_lookup_elem(&vip2tnl, &vip);
+	/* It only does v6-in-v6 */
+	if (!tnl || tnl->family != AF_INET6)
+		return XDP_PASS;
+
+	/* The vip key is found.  Add an IP header and send it out */
+
+	if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct ipv6hdr)))
+		return XDP_DROP;
+
+	data = (void *)(long)xdp->data;
+	data_end = (void *)(long)xdp->data_end;
+
+	new_eth = data;
+	ip6h = data + sizeof(*new_eth);
+	old_eth = data + sizeof(*ip6h);
+
+	if (new_eth + 1 > data_end ||
+	    old_eth + 1 > data_end ||
+	    ip6h + 1 > data_end)
+		return XDP_DROP;
+
+	set_ethhdr(new_eth, old_eth, tnl, htons(ETH_P_IPV6));
+
+	ip6h->version = 6;
+	ip6h->priority = 0;
+	memset(ip6h->flow_lbl, 0, sizeof(ip6h->flow_lbl));
+	ip6h->payload_len = htons(ntohs(payload_len) + sizeof(*ip6h));
+	ip6h->nexthdr = IPPROTO_IPV6;
+	ip6h->hop_limit = 8;
+	memcpy(ip6h->saddr.s6_addr32, tnl->saddr.v6, sizeof(tnl->saddr.v6));
+	memcpy(ip6h->daddr.s6_addr32, tnl->daddr.v6, sizeof(tnl->daddr.v6));
+
+	count_tx(vip.protocol);
+
+	return XDP_TX;
+}
+
+SEC("xdp.frags")
+int _xdp_tx_iptunnel(struct xdp_md *xdp)
+{
+	void *data_end = (void *)(long)xdp->data_end;
+	void *data = (void *)(long)xdp->data;
+	struct ethhdr *eth = data;
+	__u16 h_proto;
+
+	if (eth + 1 > data_end)
+		return XDP_DROP;
+
+	h_proto = eth->h_proto;
+
+	if (h_proto == htons(ETH_P_IP))
+		return handle_ipv4(xdp);
+	else if (h_proto == htons(ETH_P_IPV6))
+
+		return handle_ipv6(xdp);
+	else
+		return XDP_PASS;
+}
+
+char _license[] SEC("license") = "GPL";
diff --git a/samples/bpf/xdp_tx_iptunnel_user.c b/samples/bpf/xdp_tx_iptunnel_user.c
new file mode 100644
index 000000000..7e4b2f710
--- /dev/null
+++ b/samples/bpf/xdp_tx_iptunnel_user.c
@@ -0,0 +1,310 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* Copyright (c) 2016 Facebook
+ */
+#include <linux/bpf.h>
+#include <linux/if_link.h>
+#include <assert.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <net/if.h>
+#include <arpa/inet.h>
+#include <netinet/ether.h>
+#include <unistd.h>
+#include <time.h>
+#include <bpf/libbpf.h>
+#include <bpf/bpf.h>
+#include "bpf_util.h"
+#include "xdp_tx_iptunnel_common.h"
+
+#define STATS_INTERVAL_S 2U
+
+static int ifindex = -1;
+static __u32 xdp_flags = XDP_FLAGS_UPDATE_IF_NOEXIST;
+static int rxcnt_map_fd;
+static __u32 prog_id;
+
+static void int_exit(int sig)
+{
+	__u32 curr_prog_id = 0;
+
+	if (ifindex > -1) {
+		if (bpf_xdp_query_id(ifindex, xdp_flags, &curr_prog_id)) {
+			printf("bpf_xdp_query_id failed\n");
+			exit(1);
+		}
+		if (prog_id == curr_prog_id)
+			bpf_xdp_detach(ifindex, xdp_flags, NULL);
+		else if (!curr_prog_id)
+			printf("couldn't find a prog id on a given iface\n");
+		else
+			printf("program on interface changed, not removing\n");
+	}
+	exit(0);
+}
+
+/* simple per-protocol drop counter
+ */
+static void poll_stats(unsigned int kill_after_s)
+{
+	const unsigned int nr_protos = 256;
+	unsigned int nr_cpus = bpf_num_possible_cpus();
+	time_t started_at = time(NULL);
+	__u64 values[nr_cpus], prev[nr_protos][nr_cpus];
+	__u32 proto;
+	int i;
+
+	memset(prev, 0, sizeof(prev));
+
+	while (!kill_after_s || time(NULL) - started_at <= kill_after_s) {
+		sleep(STATS_INTERVAL_S);
+
+		for (proto = 0; proto < nr_protos; proto++) {
+			__u64 sum = 0;
+
+			assert(bpf_map_lookup_elem(rxcnt_map_fd, &proto,
+						   values) == 0);
+			for (i = 0; i < nr_cpus; i++)
+				sum += (values[i] - prev[proto][i]);
+
+			if (sum)
+				printf("proto %u: sum:%10llu pkts, rate:%10llu pkts/s\n",
+				       proto, sum, sum / STATS_INTERVAL_S);
+			memcpy(prev[proto], values, sizeof(values));
+		}
+	}
+}
+
+static void usage(const char *cmd)
+{
+	printf("Start a XDP prog which encapsulates incoming packets\n"
+	       "in an IPv4/v6 header and XDP_TX it out.  The dst <VIP:PORT>\n"
+	       "is used to select packets to encapsulate\n\n");
+	printf("Usage: %s [...]\n", cmd);
+	printf("    -i <ifname|ifindex> Interface\n");
+	printf("    -a <vip-service-address> IPv4 or IPv6\n");
+	printf("    -p <vip-service-port> A port range (e.g. 433-444) is also allowed\n");
+	printf("    -s <source-ip> Used in the IPTunnel header\n");
+	printf("    -d <dest-ip> Used in the IPTunnel header\n");
+	printf("    -m <dest-MAC> Used in sending the IP Tunneled pkt\n");
+	printf("    -T <stop-after-X-seconds> Default: 0 (forever)\n");
+	printf("    -P <IP-Protocol> Default is TCP\n");
+	printf("    -S use skb-mode\n");
+	printf("    -N enforce native mode\n");
+	printf("    -F Force loading the XDP prog\n");
+	printf("    -h Display this help\n");
+}
+
+static int parse_ipstr(const char *ipstr, unsigned int *addr)
+{
+	if (inet_pton(AF_INET6, ipstr, addr) == 1) {
+		return AF_INET6;
+	} else if (inet_pton(AF_INET, ipstr, addr) == 1) {
+		addr[1] = addr[2] = addr[3] = 0;
+		return AF_INET;
+	}
+
+	fprintf(stderr, "%s is an invalid IP\n", ipstr);
+	return AF_UNSPEC;
+}
+
+static int parse_ports(const char *port_str, int *min_port, int *max_port)
+{
+	char *end;
+	long tmp_min_port;
+	long tmp_max_port;
+
+	tmp_min_port = strtol(optarg, &end, 10);
+	if (tmp_min_port < 1 || tmp_min_port > 65535) {
+		fprintf(stderr, "Invalid port(s):%s\n", optarg);
+		return 1;
+	}
+
+	if (*end == '-') {
+		end++;
+		tmp_max_port = strtol(end, NULL, 10);
+		if (tmp_max_port < 1 || tmp_max_port > 65535) {
+			fprintf(stderr, "Invalid port(s):%s\n", optarg);
+			return 1;
+		}
+	} else {
+		tmp_max_port = tmp_min_port;
+	}
+
+	if (tmp_min_port > tmp_max_port) {
+		fprintf(stderr, "Invalid port(s):%s\n", optarg);
+		return 1;
+	}
+
+	if (tmp_max_port - tmp_min_port + 1 > MAX_IPTNL_ENTRIES) {
+		fprintf(stderr, "Port range (%s) is larger than %u\n",
+			port_str, MAX_IPTNL_ENTRIES);
+		return 1;
+	}
+	*min_port = tmp_min_port;
+	*max_port = tmp_max_port;
+
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+	int min_port = 0, max_port = 0, vip2tnl_map_fd;
+	const char *optstr = "i:a:p:s:d:m:T:P:FSNh";
+	unsigned char opt_flags[256] = {};
+	struct bpf_prog_info info = {};
+	__u32 info_len = sizeof(info);
+	unsigned int kill_after_s = 0;
+	struct iptnl_info tnl = {};
+	struct bpf_program *prog;
+	struct bpf_object *obj;
+	struct vip vip = {};
+	char filename[256];
+	int opt, prog_fd;
+	int i, err;
+
+	tnl.family = AF_UNSPEC;
+	vip.protocol = IPPROTO_TCP;
+
+	for (i = 0; i < strlen(optstr); i++)
+		if (optstr[i] != 'h' && 'a' <= optstr[i] && optstr[i] <= 'z')
+			opt_flags[(unsigned char)optstr[i]] = 1;
+
+	while ((opt = getopt(argc, argv, optstr)) != -1) {
+		unsigned short family;
+		unsigned int *v6;
+
+		switch (opt) {
+		case 'i':
+			ifindex = if_nametoindex(optarg);
+			if (!ifindex)
+				ifindex = atoi(optarg);
+			break;
+		case 'a':
+			vip.family = parse_ipstr(optarg, vip.daddr.v6);
+			if (vip.family == AF_UNSPEC)
+				return 1;
+			break;
+		case 'p':
+			if (parse_ports(optarg, &min_port, &max_port))
+				return 1;
+			break;
+		case 'P':
+			vip.protocol = atoi(optarg);
+			break;
+		case 's':
+		case 'd':
+			if (opt == 's')
+				v6 = tnl.saddr.v6;
+			else
+				v6 = tnl.daddr.v6;
+
+			family = parse_ipstr(optarg, v6);
+			if (family == AF_UNSPEC)
+				return 1;
+			if (tnl.family == AF_UNSPEC) {
+				tnl.family = family;
+			} else if (tnl.family != family) {
+				fprintf(stderr,
+					"The IP version of the src and dst addresses used in the IP encapsulation does not match\n");
+				return 1;
+			}
+			break;
+		case 'm':
+			if (!ether_aton_r(optarg,
+					  (struct ether_addr *)tnl.dmac)) {
+				fprintf(stderr, "Invalid mac address:%s\n",
+					optarg);
+				return 1;
+			}
+			break;
+		case 'T':
+			kill_after_s = atoi(optarg);
+			break;
+		case 'S':
+			xdp_flags |= XDP_FLAGS_SKB_MODE;
+			break;
+		case 'N':
+			/* default, set below */
+			break;
+		case 'F':
+			xdp_flags &= ~XDP_FLAGS_UPDATE_IF_NOEXIST;
+			break;
+		default:
+			usage(argv[0]);
+			return 1;
+		}
+		opt_flags[opt] = 0;
+	}
+
+	if (!(xdp_flags & XDP_FLAGS_SKB_MODE))
+		xdp_flags |= XDP_FLAGS_DRV_MODE;
+
+	for (i = 0; i < strlen(optstr); i++) {
+		if (opt_flags[(unsigned int)optstr[i]]) {
+			fprintf(stderr, "Missing argument -%c\n", optstr[i]);
+			usage(argv[0]);
+			return 1;
+		}
+	}
+
+	if (!ifindex) {
+		fprintf(stderr, "Invalid ifname\n");
+		return 1;
+	}
+
+	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
+
+	obj = bpf_object__open_file(filename, NULL);
+	if (libbpf_get_error(obj))
+		return 1;
+
+	prog = bpf_object__next_program(obj, NULL);
+	bpf_program__set_type(prog, BPF_PROG_TYPE_XDP);
+
+	err = bpf_object__load(obj);
+	if (err) {
+		printf("bpf_object__load(): %s\n", strerror(errno));
+		return 1;
+	}
+	prog_fd = bpf_program__fd(prog);
+
+	rxcnt_map_fd = bpf_object__find_map_fd_by_name(obj, "rxcnt");
+	vip2tnl_map_fd = bpf_object__find_map_fd_by_name(obj, "vip2tnl");
+	if (vip2tnl_map_fd < 0 || rxcnt_map_fd < 0) {
+		printf("bpf_object__find_map_fd_by_name failed\n");
+		return 1;
+	}
+
+	signal(SIGINT, int_exit);
+	signal(SIGTERM, int_exit);
+
+	while (min_port <= max_port) {
+		vip.dport = htons(min_port++);
+		if (bpf_map_update_elem(vip2tnl_map_fd, &vip, &tnl,
+					BPF_NOEXIST)) {
+			perror("bpf_map_update_elem(&vip2tnl)");
+			return 1;
+		}
+	}
+
+	if (bpf_xdp_attach(ifindex, prog_fd, xdp_flags, NULL) < 0) {
+		printf("link set xdp fd failed\n");
+		return 1;
+	}
+
+	err = bpf_prog_get_info_by_fd(prog_fd, &info, &info_len);
+	if (err) {
+		printf("can't get prog info - %s\n", strerror(errno));
+		return err;
+	}
+	prog_id = info.id;
+
+	poll_stats(kill_after_s);
+
+	bpf_xdp_detach(ifindex, xdp_flags, NULL);
+
+	return 0;
+}