Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 866 insertions, 0 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
new file mode 100644
index 000000000..6f602df72
--- /dev/null
+++ b/include/net/ip.h
@@ -0,0 +1,866 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Definitions for the IP module.
+ *
+ * Version:	@(#)ip.h	1.0.2	05/07/93
+ *
+ * Authors:	Ross Biro
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *
+ * Changes:
+ *		Mike McLagan    :       Routing by source
+ */
+#ifndef _IP_H
+#define _IP_H
+
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/in.h>
+#include <linux/skbuff.h>
+#include <linux/jhash.h>
+#include <linux/sockptr.h>
+#include <linux/static_key.h>
+
+#include <net/inet_sock.h>
+#include <net/route.h>
+#include <net/snmp.h>
+#include <net/flow.h>
+#include <net/flow_dissector.h>
+#include <net/netns/hash.h>
+#include <net/lwtunnel.h>
+#include <net/inet_dscp.h>
+
+#define IPV4_MAX_PMTU		65535U		/* RFC 2675, Section 5.1 */
+#define IPV4_MIN_MTU		68			/* RFC 791 */
+
+extern unsigned int sysctl_fib_sync_mem;
+extern unsigned int sysctl_fib_sync_mem_min;
+extern unsigned int sysctl_fib_sync_mem_max;
+
+struct sock;
+
+struct inet_skb_parm {
+	int			iif;
+	struct ip_options	opt;		/* Compiled IP options		*/
+	u16			flags;
+
+#define IPSKB_FORWARDED		BIT(0)
+#define IPSKB_XFRM_TUNNEL_SIZE	BIT(1)
+#define IPSKB_XFRM_TRANSFORMED	BIT(2)
+#define IPSKB_FRAG_COMPLETE	BIT(3)
+#define IPSKB_REROUTED		BIT(4)
+#define IPSKB_DOREDIRECT	BIT(5)
+#define IPSKB_FRAG_PMTU		BIT(6)
+#define IPSKB_L3SLAVE		BIT(7)
+#define IPSKB_NOPOLICY		BIT(8)
+#define IPSKB_MULTIPATH		BIT(9)
+#define IPSKB_MCROUTE		BIT(10)
+
+	u16			frag_max_size;
+};
+
+static inline bool ipv4_l3mdev_skb(u16 flags)
+{
+	return !!(flags & IPSKB_L3SLAVE);
+}
+
+static inline unsigned int ip_hdrlen(const struct sk_buff *skb)
+{
+	return ip_hdr(skb)->ihl * 4;
+}
+
+struct ipcm_cookie {
+	struct sockcm_cookie	sockc;
+	__be32			addr;
+	int			oif;
+	struct ip_options_rcu	*opt;
+	__u8			protocol;
+	__u8			ttl;
+	__s16			tos;
+	__u16			gso_size;
+};
+
+static inline void ipcm_init(struct ipcm_cookie *ipcm)
+{
+	*ipcm = (struct ipcm_cookie) { .tos = -1 };
+}
+
+static inline void ipcm_init_sk(struct ipcm_cookie *ipcm,
+				const struct inet_sock *inet)
+{
+	*ipcm = (struct ipcm_cookie) {
+		.tos = READ_ONCE(inet->tos),
+	};
+
+	sockcm_init(&ipcm->sockc, &inet->sk);
+
+	ipcm->oif = READ_ONCE(inet->sk.sk_bound_dev_if);
+	ipcm->addr = inet->inet_saddr;
+	ipcm->protocol = READ_ONCE(inet->inet_num);
+}
+
+#define IPCB(skb) ((struct inet_skb_parm*)((skb)->cb))
+#define PKTINFO_SKB_CB(skb) ((struct in_pktinfo *)((skb)->cb))
+
+/* return enslaved device index if relevant */
+static inline int inet_sdif(const struct sk_buff *skb)
+{
+#if IS_ENABLED(CONFIG_NET_L3_MASTER_DEV)
+	if (skb && ipv4_l3mdev_skb(IPCB(skb)->flags))
+		return IPCB(skb)->iif;
+#endif
+	return 0;
+}
+
+/* Special input handler for packets caught by router alert option.
+   They are selected only by protocol field, and then processed likely
+   local ones; but only if someone wants them! Otherwise, router
+   not running rsvpd will kill RSVP.
+
+   It is user level problem, what it will make with them.
+   I have no idea, how it will masquearde or NAT them (it is joke, joke :-)),
+   but receiver should be enough clever f.e. to forward mtrace requests,
+   sent to multicast group to reach destination designated router.
+ */
+
+struct ip_ra_chain {
+	struct ip_ra_chain __rcu *next;
+	struct sock		*sk;
+	union {
+		void			(*destructor)(struct sock *);
+		struct sock		*saved_sk;
+	};
+	struct rcu_head		rcu;
+};
+
+/* IP flags. */
+#define IP_CE		0x8000		/* Flag: "Congestion"		*/
+#define IP_DF		0x4000		/* Flag: "Don't Fragment"	*/
+#define IP_MF		0x2000		/* Flag: "More Fragments"	*/
+#define IP_OFFSET	0x1FFF		/* "Fragment Offset" part	*/
+
+#define IP_FRAG_TIME	(30 * HZ)		/* fragment lifetime	*/
+
+struct msghdr;
+struct net_device;
+struct packet_type;
+struct rtable;
+struct sockaddr;
+
+int igmp_mc_init(void);
+
+/*
+ *	Functions provided by ip.c
+ */
+
+int ip_build_and_send_pkt(struct sk_buff *skb, const struct sock *sk,
+			  __be32 saddr, __be32 daddr,
+			  struct ip_options_rcu *opt, u8 tos);
+int ip_rcv(struct sk_buff *skb, struct net_device *dev, struct packet_type *pt,
+	   struct net_device *orig_dev);
+void ip_list_rcv(struct list_head *head, struct packet_type *pt,
+		 struct net_device *orig_dev);
+int ip_local_deliver(struct sk_buff *skb);
+void ip_protocol_deliver_rcu(struct net *net, struct sk_buff *skb, int proto);
+int ip_mr_input(struct sk_buff *skb);
+int ip_mr_output(struct net *net, struct sock *sk, struct sk_buff *skb);
+int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb);
+int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb);
+int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb,
+		   int (*output)(struct net *, struct sock *, struct sk_buff *));
+
+struct ip_fraglist_iter {
+	struct sk_buff	*frag;
+	struct iphdr	*iph;
+	int		offset;
+	unsigned int	hlen;
+};
+
+void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph,
+		      unsigned int hlen, struct ip_fraglist_iter *iter);
+void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter);
+
+static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter)
+{
+	struct sk_buff *skb = iter->frag;
+
+	iter->frag = skb->next;
+	skb_mark_not_on_list(skb);
+
+	return skb;
+}
+
+struct ip_frag_state {
+	bool		DF;
+	unsigned int	hlen;
+	unsigned int	ll_rs;
+	unsigned int	mtu;
+	unsigned int	left;
+	int		offset;
+	int		ptr;
+	__be16		not_last_frag;
+};
+
+void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs,
+		  unsigned int mtu, bool DF, struct ip_frag_state *state);
+struct sk_buff *ip_frag_next(struct sk_buff *skb,
+			     struct ip_frag_state *state);
+
+void ip_send_check(struct iphdr *ip);
+int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
+int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb);
+
+int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
+		    __u8 tos);
+void ip_init(void);
+int ip_append_data(struct sock *sk, struct flowi4 *fl4,
+		   int getfrag(void *from, char *to, int offset, int len,
+			       int odd, struct sk_buff *skb),
+		   void *from, int len, int protolen,
+		   struct ipcm_cookie *ipc,
+		   struct rtable **rt,
+		   unsigned int flags);
+int ip_generic_getfrag(void *from, char *to, int offset, int len, int odd,
+		       struct sk_buff *skb);
+struct sk_buff *__ip_make_skb(struct sock *sk, struct flowi4 *fl4,
+			      struct sk_buff_head *queue,
+			      struct inet_cork *cork);
+int ip_send_skb(struct net *net, struct sk_buff *skb);
+int ip_push_pending_frames(struct sock *sk, struct flowi4 *fl4);
+void ip_flush_pending_frames(struct sock *sk);
+struct sk_buff *ip_make_skb(struct sock *sk, struct flowi4 *fl4,
+			    int getfrag(void *from, char *to, int offset,
+					int len, int odd, struct sk_buff *skb),
+			    void *from, int length, int transhdrlen,
+			    struct ipcm_cookie *ipc, struct rtable **rtp,
+			    struct inet_cork *cork, unsigned int flags);
+
+int ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl);
+
+static inline struct sk_buff *ip_finish_skb(struct sock *sk, struct flowi4 *fl4)
+{
+	return __ip_make_skb(sk, fl4, &sk->sk_write_queue, &inet_sk(sk)->cork.base);
+}
+
+/* Get the route scope that should be used when sending a packet. */
+static inline u8 ip_sendmsg_scope(const struct inet_sock *inet,
+				  const struct ipcm_cookie *ipc,
+				  const struct msghdr *msg)
+{
+	if (sock_flag(&inet->sk, SOCK_LOCALROUTE) ||
+	    msg->msg_flags & MSG_DONTROUTE ||
+	    (ipc->opt && ipc->opt->opt.is_strictroute))
+		return RT_SCOPE_LINK;
+
+	return RT_SCOPE_UNIVERSE;
+}
+
+/* datagram.c */
+int __ip4_datagram_connect(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len);
+int ip4_datagram_connect(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len);
+
+void ip4_datagram_release_cb(struct sock *sk);
+
+struct ip_reply_arg {
+	struct kvec iov[1];
+	int	    flags;
+	__wsum 	    csum;
+	int	    csumoffset; /* u16 offset of csum in iov[0].iov_base */
+				/* -1 if not needed */
+	int	    bound_dev_if;
+	u8  	    tos;
+	kuid_t	    uid;
+};
+
+#define IP_REPLY_ARG_NOSRCCHECK 1
+
+static inline __u8 ip_reply_arg_flowi_flags(const struct ip_reply_arg *arg)
+{
+	return (arg->flags & IP_REPLY_ARG_NOSRCCHECK) ? FLOWI_FLAG_ANYSRC : 0;
+}
+
+void ip_send_unicast_reply(struct sock *sk, const struct sock *orig_sk,
+			   struct sk_buff *skb,
+			   const struct ip_options *sopt,
+			   __be32 daddr, __be32 saddr,
+			   const struct ip_reply_arg *arg,
+			   unsigned int len, u64 transmit_time, u32 txhash);
+
+#define IP_INC_STATS(net, field)	SNMP_INC_STATS64((net)->mib.ip_statistics, field)
+#define __IP_INC_STATS(net, field)	__SNMP_INC_STATS64((net)->mib.ip_statistics, field)
+#define IP_ADD_STATS(net, field, val)	SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
+#define __IP_ADD_STATS(net, field, val) __SNMP_ADD_STATS64((net)->mib.ip_statistics, field, val)
+#define IP_UPD_PO_STATS(net, field, val) SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
+#define __IP_UPD_PO_STATS(net, field, val) __SNMP_UPD_PO_STATS64((net)->mib.ip_statistics, field, val)
+#define NET_INC_STATS(net, field)	SNMP_INC_STATS((net)->mib.net_statistics, field)
+#define __NET_INC_STATS(net, field)	__SNMP_INC_STATS((net)->mib.net_statistics, field)
+#define NET_ADD_STATS(net, field, adnd)	SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
+#define __NET_ADD_STATS(net, field, adnd) __SNMP_ADD_STATS((net)->mib.net_statistics, field, adnd)
+
+static inline u64 snmp_get_cpu_field(void __percpu *mib, int cpu, int offt)
+{
+	return  *(((unsigned long *)per_cpu_ptr(mib, cpu)) + offt);
+}
+
+unsigned long snmp_fold_field(void __percpu *mib, int offt);
+#if BITS_PER_LONG==32
+u64 snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+			 size_t syncp_offset);
+u64 snmp_fold_field64(void __percpu *mib, int offt, size_t sync_off);
+#else
+static inline u64  snmp_get_cpu_field64(void __percpu *mib, int cpu, int offct,
+					size_t syncp_offset)
+{
+	return snmp_get_cpu_field(mib, cpu, offct);
+
+}
+
+static inline u64 snmp_fold_field64(void __percpu *mib, int offt, size_t syncp_off)
+{
+	return snmp_fold_field(mib, offt);
+}
+#endif
+
+#define snmp_get_cpu_field64_batch_cnt(buff64, stats_list, cnt,	\
+				       mib_statistic, offset)	\
+{ \
+	int i, c; \
+	for_each_possible_cpu(c) { \
+		for (i = 0; i < cnt; i++) \
+			buff64[i] += snmp_get_cpu_field64( \
+					mib_statistic, \
+					c, stats_list[i].entry, \
+					offset); \
+	} \
+}
+
+#define snmp_get_cpu_field_batch_cnt(buff, stats_list, cnt, mib_statistic) \
+{ \
+	int i, c; \
+	for_each_possible_cpu(c) { \
+		for (i = 0; i < cnt; i++) \
+			buff[i] += snmp_get_cpu_field( \
+						mib_statistic, \
+						c, stats_list[i].entry); \
+	} \
+}
+
+static inline void inet_get_local_port_range(const struct net *net, int *low, int *high)
+{
+	u32 range = READ_ONCE(net->ipv4.ip_local_ports.range);
+
+	*low = range & 0xffff;
+	*high = range >> 16;
+}
+bool inet_sk_get_local_port_range(const struct sock *sk, int *low, int *high);
+
+#ifdef CONFIG_SYSCTL
+static inline bool inet_is_local_reserved_port(const struct net *net, unsigned short port)
+{
+	if (!net->ipv4.sysctl_local_reserved_ports)
+		return false;
+	return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
+}
+
+static inline bool sysctl_dev_name_is_allowed(const char *name)
+{
+	return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
+}
+
+static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
+{
+	return port < READ_ONCE(net->ipv4.sysctl_ip_prot_sock);
+}
+
+#else
+static inline bool inet_is_local_reserved_port(struct net *net, unsigned short port)
+{
+	return false;
+}
+
+static inline bool inet_port_requires_bind_service(struct net *net, unsigned short port)
+{
+	return port < PROT_SOCK;
+}
+#endif
+
+__be32 inet_current_timestamp(void);
+
+/* From inetpeer.c */
+extern int inet_peer_threshold;
+extern int inet_peer_minttl;
+extern int inet_peer_maxttl;
+
+void ipfrag_init(void);
+
+void ip_static_sysctl_init(void);
+
+#define IP4_REPLY_MARK(net, mark) \
+	(READ_ONCE((net)->ipv4.sysctl_fwmark_reflect) ? (mark) : 0)
+
+static inline bool ip_is_fragment(const struct iphdr *iph)
+{
+	return (iph->frag_off & htons(IP_MF | IP_OFFSET)) != 0;
+}
+
+#ifdef CONFIG_INET
+#include <net/dst.h>
+
+/* The function in 2.2 was invalid, producing wrong result for
+ * check=0xFEFF. It was noticed by Arthur Skawina _year_ ago. --ANK(000625) */
+static 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 inline dscp_t ip4h_dscp(const struct iphdr *ip4h)
+{
+	return inet_dsfield_to_dscp(ip4h->tos);
+}
+
+static inline int ip_mtu_locked(const struct dst_entry *dst)
+{
+	const struct rtable *rt = dst_rtable(dst);
+
+	return rt->rt_mtu_locked || dst_metric_locked(dst, RTAX_MTU);
+}
+
+static inline
+int ip_dont_fragment(const struct sock *sk, const struct dst_entry *dst)
+{
+	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
+
+	return  pmtudisc == IP_PMTUDISC_DO ||
+		(pmtudisc == IP_PMTUDISC_WANT &&
+		 !ip_mtu_locked(dst));
+}
+
+static inline bool ip_sk_accept_pmtu(const struct sock *sk)
+{
+	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
+
+	return pmtudisc != IP_PMTUDISC_INTERFACE &&
+	       pmtudisc != IP_PMTUDISC_OMIT;
+}
+
+static inline bool ip_sk_use_pmtu(const struct sock *sk)
+{
+	return READ_ONCE(inet_sk(sk)->pmtudisc) < IP_PMTUDISC_PROBE;
+}
+
+static inline bool ip_sk_ignore_df(const struct sock *sk)
+{
+	u8 pmtudisc = READ_ONCE(inet_sk(sk)->pmtudisc);
+
+	return pmtudisc < IP_PMTUDISC_DO || pmtudisc == IP_PMTUDISC_OMIT;
+}
+
+static inline unsigned int ip_dst_mtu_maybe_forward(const struct dst_entry *dst,
+						    bool forwarding)
+{
+	const struct rtable *rt = dst_rtable(dst);
+	const struct net_device *dev;
+	unsigned int mtu, res;
+	struct net *net;
+
+	rcu_read_lock();
+
+	dev = dst_dev_rcu(dst);
+	net = dev_net_rcu(dev);
+	if (READ_ONCE(net->ipv4.sysctl_ip_fwd_use_pmtu) ||
+	    ip_mtu_locked(dst) ||
+	    !forwarding) {
+		mtu = rt->rt_pmtu;
+		if (mtu && time_before(jiffies, READ_ONCE(rt->dst.expires)))
+			goto out;
+	}
+
+	/* 'forwarding = true' case should always honour route mtu */
+	mtu = dst_metric_raw(dst, RTAX_MTU);
+	if (mtu)
+		goto out;
+
+	mtu = READ_ONCE(dev->mtu);
+
+	if (unlikely(ip_mtu_locked(dst))) {
+		if (rt->rt_uses_gateway && mtu > 576)
+			mtu = 576;
+	}
+
+out:
+	mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
+
+	res = mtu - lwtunnel_headroom(dst->lwtstate, mtu);
+
+	rcu_read_unlock();
+
+	return res;
+}
+
+/* Configured/administrative MTU of a route, for advertising the TCP MSS.
+ *
+ * Unlike ip_dst_mtu_maybe_forward(), this deliberately ignores the
+ * ICMP-learned path MTU (rt->rt_pmtu).  The advertised MSS bounds what the
+ * peer may send to us and must reflect our receive capability (the device or
+ * route-configured MTU), not a path MTU learned on the reverse (send)
+ * direction, which may not apply to the peer->us path and outlives the fnhe
+ * for the whole connection.  See RFC 2923 section 2.3 and the comment above
+ * tcp_advertise_mss().
+ */
+static inline unsigned int ip_dst_mtu_configured(const struct dst_entry *dst)
+{
+	unsigned int mtu, res;
+
+	rcu_read_lock();
+	mtu = dst_metric_raw(dst, RTAX_MTU);
+	if (!mtu)
+		mtu = READ_ONCE(dst_dev_rcu(dst)->mtu);
+	mtu = min_t(unsigned int, mtu, IP_MAX_MTU);
+	res = mtu - lwtunnel_headroom(dst->lwtstate, mtu);
+	rcu_read_unlock();
+
+	return res;
+}
+
+static inline unsigned int ip_skb_dst_mtu(struct sock *sk,
+					  const struct sk_buff *skb)
+{
+	const struct dst_entry *dst = skb_dst(skb);
+	unsigned int mtu;
+
+	if (!sk || !sk_fullsock(sk) || ip_sk_use_pmtu(sk)) {
+		bool forwarding = IPCB(skb)->flags & IPSKB_FORWARDED;
+
+		return ip_dst_mtu_maybe_forward(dst, forwarding);
+	}
+
+	mtu = min(READ_ONCE(dst_dev(dst)->mtu), IP_MAX_MTU);
+	return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
+}
+
+struct dst_metrics *ip_fib_metrics_init(struct nlattr *fc_mx, int fc_mx_len,
+					struct netlink_ext_ack *extack);
+static inline void ip_fib_metrics_put(struct dst_metrics *fib_metrics)
+{
+	if (fib_metrics != &dst_default_metrics &&
+	    refcount_dec_and_test(&fib_metrics->refcnt))
+		kfree(fib_metrics);
+}
+
+/* ipv4 and ipv6 both use refcounted metrics if it is not the default */
+static inline
+void ip_dst_init_metrics(struct dst_entry *dst, struct dst_metrics *fib_metrics)
+{
+	dst_init_metrics(dst, fib_metrics->metrics, true);
+
+	if (fib_metrics != &dst_default_metrics) {
+		dst->_metrics |= DST_METRICS_REFCOUNTED;
+		refcount_inc(&fib_metrics->refcnt);
+	}
+}
+
+static inline
+void ip_dst_metrics_put(struct dst_entry *dst)
+{
+	struct dst_metrics *p = (struct dst_metrics *)DST_METRICS_PTR(dst);
+
+	if (p != &dst_default_metrics && refcount_dec_and_test(&p->refcnt))
+		kfree(p);
+}
+
+void __ip_select_ident(struct net *net, struct iphdr *iph, int segs);
+
+static inline void ip_select_ident_segs(struct net *net, struct sk_buff *skb,
+					struct sock *sk, int segs)
+{
+	struct iphdr *iph = ip_hdr(skb);
+
+	/* We had many attacks based on IPID, use the private
+	 * generator as much as we can.
+	 */
+	if (sk && inet_sk(sk)->inet_daddr) {
+		int val;
+
+		/* avoid atomic operations for TCP,
+		 * as we hold socket lock at this point.
+		 */
+		if (sk_is_tcp(sk)) {
+			sock_owned_by_me(sk);
+			val = atomic_read(&inet_sk(sk)->inet_id);
+			atomic_set(&inet_sk(sk)->inet_id, val + segs);
+		} else {
+			val = atomic_add_return(segs, &inet_sk(sk)->inet_id);
+		}
+		iph->id = htons(val);
+		return;
+	}
+	if ((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) {
+		iph->id = 0;
+	} else {
+		/* Unfortunately we need the big hammer to get a suitable IPID */
+		__ip_select_ident(net, iph, segs);
+	}
+}
+
+static inline void ip_select_ident(struct net *net, struct sk_buff *skb,
+				   struct sock *sk)
+{
+	ip_select_ident_segs(net, skb, sk, 1);
+}
+
+static inline __wsum inet_compute_pseudo(struct sk_buff *skb, int proto)
+{
+	return csum_tcpudp_nofold(ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
+				  skb->len, proto, 0);
+}
+
+/* copy IPv4 saddr & daddr to flow_keys, possibly using 64bit load/store
+ * Equivalent to :	flow->v4addrs.src = iph->saddr;
+ *			flow->v4addrs.dst = iph->daddr;
+ */
+static inline void iph_to_flow_copy_v4addrs(struct flow_keys *flow,
+					    const struct iphdr *iph)
+{
+	BUILD_BUG_ON(offsetof(typeof(flow->addrs), v4addrs.dst) !=
+		     offsetof(typeof(flow->addrs), v4addrs.src) +
+			      sizeof(flow->addrs.v4addrs.src));
+	memcpy(&flow->addrs.v4addrs, &iph->addrs, sizeof(flow->addrs.v4addrs));
+	flow->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
+}
+
+/*
+ *	Map a multicast IP onto multicast MAC for type ethernet.
+ */
+
+static inline void ip_eth_mc_map(__be32 naddr, char *buf)
+{
+	__u32 addr=ntohl(naddr);
+	buf[0]=0x01;
+	buf[1]=0x00;
+	buf[2]=0x5e;
+	buf[5]=addr&0xFF;
+	addr>>=8;
+	buf[4]=addr&0xFF;
+	addr>>=8;
+	buf[3]=addr&0x7F;
+}
+
+/*
+ *	Map a multicast IP onto multicast MAC for type IP-over-InfiniBand.
+ *	Leave P_Key as 0 to be filled in by driver.
+ */
+
+static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
+{
+	__u32 addr;
+	unsigned char scope = broadcast[5] & 0xF;
+
+	buf[0]  = 0;		/* Reserved */
+	buf[1]  = 0xff;		/* Multicast QPN */
+	buf[2]  = 0xff;
+	buf[3]  = 0xff;
+	addr    = ntohl(naddr);
+	buf[4]  = 0xff;
+	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
+	buf[6]  = 0x40;		/* IPv4 signature */
+	buf[7]  = 0x1b;
+	buf[8]  = broadcast[8];		/* P_Key */
+	buf[9]  = broadcast[9];
+	buf[10] = 0;
+	buf[11] = 0;
+	buf[12] = 0;
+	buf[13] = 0;
+	buf[14] = 0;
+	buf[15] = 0;
+	buf[19] = addr & 0xff;
+	addr  >>= 8;
+	buf[18] = addr & 0xff;
+	addr  >>= 8;
+	buf[17] = addr & 0xff;
+	addr  >>= 8;
+	buf[16] = addr & 0x0f;
+}
+
+static inline void ip_ipgre_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
+{
+	if ((broadcast[0] | broadcast[1] | broadcast[2] | broadcast[3]) != 0)
+		memcpy(buf, broadcast, 4);
+	else
+		memcpy(buf, &naddr, sizeof(naddr));
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+#include <linux/ipv6.h>
+#endif
+
+static __inline__ void inet_reset_saddr(struct sock *sk)
+{
+	inet_sk(sk)->inet_saddr = 0;
+	WRITE_ONCE(inet_sk(sk)->inet_rcv_saddr, 0);
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == PF_INET6) {
+		struct ipv6_pinfo *np = inet6_sk(sk);
+
+		memset(&np->saddr, 0, sizeof(np->saddr));
+		memset(&sk->sk_v6_rcv_saddr, 0, sizeof(sk->sk_v6_rcv_saddr));
+	}
+#endif
+}
+
+#endif
+
+static inline unsigned int ipv4_addr_hash(__be32 ip)
+{
+	return (__force unsigned int) ip;
+}
+
+static inline u32 __ipv4_addr_hash(const __be32 ip, const u32 initval)
+{
+	return jhash_1word((__force u32)ip, initval);
+}
+
+static inline u32 ipv4_portaddr_hash(const struct net *net,
+				     __be32 saddr,
+				     unsigned int port)
+{
+	return jhash_1word((__force u32)saddr, net_hash_mix(net)) ^ port;
+}
+
+bool ip_call_ra_chain(struct sk_buff *skb);
+
+/*
+ *	Functions provided by ip_fragment.c
+ */
+
+enum ip_defrag_users {
+	IP_DEFRAG_LOCAL_DELIVER,
+	IP_DEFRAG_CALL_RA_CHAIN,
+	IP_DEFRAG_CONNTRACK_IN,
+	__IP_DEFRAG_CONNTRACK_IN_END	= IP_DEFRAG_CONNTRACK_IN + USHRT_MAX,
+	IP_DEFRAG_CONNTRACK_OUT,
+	__IP_DEFRAG_CONNTRACK_OUT_END	= IP_DEFRAG_CONNTRACK_OUT + USHRT_MAX,
+	IP_DEFRAG_CONNTRACK_BRIDGE_IN,
+	__IP_DEFRAG_CONNTRACK_BRIDGE_IN = IP_DEFRAG_CONNTRACK_BRIDGE_IN + USHRT_MAX,
+	IP_DEFRAG_VS_IN,
+	IP_DEFRAG_VS_OUT,
+	IP_DEFRAG_VS_FWD,
+	IP_DEFRAG_AF_PACKET,
+	IP_DEFRAG_MACVLAN,
+};
+
+/* Return true if the value of 'user' is between 'lower_bond'
+ * and 'upper_bond' inclusively.
+ */
+static inline bool ip_defrag_user_in_between(u32 user,
+					     enum ip_defrag_users lower_bond,
+					     enum ip_defrag_users upper_bond)
+{
+	return user >= lower_bond && user <= upper_bond;
+}
+
+int ip_defrag(struct net *net, struct sk_buff *skb, u32 user);
+#ifdef CONFIG_INET
+struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user);
+#else
+static inline struct sk_buff *ip_check_defrag(struct net *net, struct sk_buff *skb, u32 user)
+{
+	return skb;
+}
+#endif
+
+/*
+ *	Functions provided by ip_forward.c
+ */
+
+int ip_forward(struct sk_buff *skb);
+
+/*
+ *	Functions provided by ip_options.c
+ */
+
+void ip_options_build(struct sk_buff *skb, struct ip_options *opt,
+		      __be32 daddr, struct rtable *rt);
+
+int __ip_options_echo(struct net *net, struct ip_options *dopt,
+		      struct sk_buff *skb, const struct ip_options *sopt);
+static inline int ip_options_echo(struct net *net, struct ip_options *dopt,
+				  struct sk_buff *skb)
+{
+	return __ip_options_echo(net, dopt, skb, &IPCB(skb)->opt);
+}
+
+void ip_options_fragment(struct sk_buff *skb);
+int __ip_options_compile(struct net *net, struct ip_options *opt,
+			 struct sk_buff *skb, __be32 *info);
+int ip_options_compile(struct net *net, struct ip_options *opt,
+		       struct sk_buff *skb);
+int ip_options_get(struct net *net, struct ip_options_rcu **optp,
+		   sockptr_t data, int optlen);
+void ip_options_undo(struct ip_options *opt);
+void ip_forward_options(struct sk_buff *skb);
+int ip_options_rcv_srr(struct sk_buff *skb, struct net_device *dev);
+
+/*
+ *	Functions provided by ip_sockglue.c
+ */
+
+void ipv4_pktinfo_prepare(const struct sock *sk, struct sk_buff *skb, bool drop_dst);
+void ip_cmsg_recv_offset(struct msghdr *msg, struct sock *sk,
+			 struct sk_buff *skb, int tlen, int offset);
+int ip_cmsg_send(struct sock *sk, struct msghdr *msg,
+		 struct ipcm_cookie *ipc, bool allow_ipv6);
+DECLARE_STATIC_KEY_FALSE(ip4_min_ttl);
+int do_ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
+		     unsigned int optlen);
+int ip_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,
+		  unsigned int optlen);
+int do_ip_getsockopt(struct sock *sk, int level, int optname,
+		     sockptr_t optval, sockptr_t optlen);
+int ip_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
+		  int __user *optlen);
+int ip_ra_control(struct sock *sk, unsigned char on,
+		  void (*destructor)(struct sock *));
+
+int ip_recv_error(struct sock *sk, struct msghdr *msg, int len);
+void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
+		   u32 info, u8 *payload);
+void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
+		    u32 info);
+
+static inline void ip_cmsg_recv(struct msghdr *msg, struct sk_buff *skb)
+{
+	ip_cmsg_recv_offset(msg, skb->sk, skb, 0, 0);
+}
+
+bool icmp_global_allow(struct net *net);
+void icmp_global_consume(struct net *net);
+
+#ifdef CONFIG_PROC_FS
+int ip_misc_proc_init(void);
+#endif
+
+int rtm_getroute_parse_ip_proto(struct nlattr *attr, u8 *ip_proto, u8 family,
+				struct netlink_ext_ack *extack);
+
+static inline bool inetdev_valid_mtu(unsigned int mtu)
+{
+	return likely(mtu >= IPV4_MIN_MTU);
+}
+
+void ip_sock_set_freebind(struct sock *sk);
+int ip_sock_set_mtu_discover(struct sock *sk, int val);
+void ip_sock_set_pktinfo(struct sock *sk);
+void ip_sock_set_recverr(struct sock *sk);
+void ip_sock_set_tos(struct sock *sk, int val);
+void  __ip_sock_set_tos(struct sock *sk, int val);
+
+#endif	/* _IP_H */