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, 1971 insertions, 0 deletions

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
new file mode 100644
index 000000000..a0557a3a7
--- /dev/null
+++ b/drivers/net/vrf.c
@@ -0,0 +1,1971 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * vrf.c: device driver to encapsulate a VRF space
+ *
+ * Copyright (c) 2015 Cumulus Networks. All rights reserved.
+ * Copyright (c) 2015 Shrijeet Mukherjee <shm@cumulusnetworks.com>
+ * Copyright (c) 2015 David Ahern <dsa@cumulusnetworks.com>
+ *
+ * Based on dummy, team and ipvlan drivers
+ */
+
+#include <linux/ethtool.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ip.h>
+#include <linux/init.h>
+#include <linux/moduleparam.h>
+#include <linux/netfilter.h>
+#include <linux/rtnetlink.h>
+#include <net/rtnetlink.h>
+#include <linux/u64_stats_sync.h>
+#include <linux/hashtable.h>
+#include <linux/spinlock_types.h>
+
+#include <linux/inetdevice.h>
+#include <net/arp.h>
+#include <net/flow.h>
+#include <net/ip.h>
+#include <net/ip_fib.h>
+#include <net/ip6_fib.h>
+#include <net/ip6_route.h>
+#include <net/route.h>
+#include <net/addrconf.h>
+#include <net/l3mdev.h>
+#include <net/fib_rules.h>
+#include <net/netdev_lock.h>
+#include <net/sch_generic.h>
+#include <net/netns/generic.h>
+#include <net/netfilter/nf_conntrack.h>
+
+#define DRV_NAME	"vrf"
+#define DRV_VERSION	"1.1"
+
+#define FIB_RULE_PREF  1000       /* default preference for FIB rules */
+
+#define HT_MAP_BITS	4
+#define HASH_INITVAL	((u32)0xcafef00d)
+
+struct  vrf_map {
+	DECLARE_HASHTABLE(ht, HT_MAP_BITS);
+	spinlock_t vmap_lock;
+
+	/* shared_tables:
+	 * count how many distinct tables do not comply with the strict mode
+	 * requirement.
+	 * shared_tables value must be 0 in order to enable the strict mode.
+	 *
+	 * example of the evolution of shared_tables:
+	 *                                                        | time
+	 * add  vrf0 --> table 100        shared_tables = 0       | t0
+	 * add  vrf1 --> table 101        shared_tables = 0       | t1
+	 * add  vrf2 --> table 100        shared_tables = 1       | t2
+	 * add  vrf3 --> table 100        shared_tables = 1       | t3
+	 * add  vrf4 --> table 101        shared_tables = 2       v t4
+	 *
+	 * shared_tables is a "step function" (or "staircase function")
+	 * and it is increased by one when the second vrf is associated to a
+	 * table.
+	 *
+	 * at t2, vrf0 and vrf2 are bound to table 100: shared_tables = 1.
+	 *
+	 * at t3, another dev (vrf3) is bound to the same table 100 but the
+	 * value of shared_tables is still 1.
+	 * This means that no matter how many new vrfs will register on the
+	 * table 100, the shared_tables will not increase (considering only
+	 * table 100).
+	 *
+	 * at t4, vrf4 is bound to table 101, and shared_tables = 2.
+	 *
+	 * Looking at the value of shared_tables we can immediately know if
+	 * the strict_mode can or cannot be enforced. Indeed, strict_mode
+	 * can be enforced iff shared_tables = 0.
+	 *
+	 * Conversely, shared_tables is decreased when a vrf is de-associated
+	 * from a table with exactly two associated vrfs.
+	 */
+	u32 shared_tables;
+
+	bool strict_mode;
+};
+
+struct vrf_map_elem {
+	struct hlist_node hnode;
+	struct list_head vrf_list;  /* VRFs registered to this table */
+
+	u32 table_id;
+	int users;
+	int ifindex;
+};
+
+static unsigned int vrf_net_id;
+
+/* per netns vrf data */
+struct netns_vrf {
+	/* protected by rtnl lock */
+	bool add_fib_rules;
+
+	struct vrf_map vmap;
+	struct ctl_table_header	*ctl_hdr;
+};
+
+struct net_vrf {
+	struct rtable		*rth;
+	struct rt6_info		*rt6;
+#if IS_ENABLED(CONFIG_IPV6)
+	struct fib6_table	*fib6_table;
+#endif
+	u32                     tb_id;
+
+	struct list_head	me_list;   /* entry in vrf_map_elem */
+	int			ifindex;
+};
+
+static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
+{
+	vrf_dev->stats.tx_errors++;
+	kfree_skb(skb);
+}
+
+static struct vrf_map *netns_vrf_map(struct net *net)
+{
+	struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
+
+	return &nn_vrf->vmap;
+}
+
+static struct vrf_map *netns_vrf_map_by_dev(struct net_device *dev)
+{
+	return netns_vrf_map(dev_net(dev));
+}
+
+static int vrf_map_elem_get_vrf_ifindex(struct vrf_map_elem *me)
+{
+	struct list_head *me_head = &me->vrf_list;
+	struct net_vrf *vrf;
+
+	if (list_empty(me_head))
+		return -ENODEV;
+
+	vrf = list_first_entry(me_head, struct net_vrf, me_list);
+
+	return vrf->ifindex;
+}
+
+static struct vrf_map_elem *vrf_map_elem_alloc(gfp_t flags)
+{
+	struct vrf_map_elem *me;
+
+	me = kmalloc_obj(*me, flags);
+	if (!me)
+		return NULL;
+
+	return me;
+}
+
+static void vrf_map_elem_free(struct vrf_map_elem *me)
+{
+	kfree(me);
+}
+
+static void vrf_map_elem_init(struct vrf_map_elem *me, int table_id,
+			      int ifindex, int users)
+{
+	me->table_id = table_id;
+	me->ifindex = ifindex;
+	me->users = users;
+	INIT_LIST_HEAD(&me->vrf_list);
+}
+
+static struct vrf_map_elem *vrf_map_lookup_elem(struct vrf_map *vmap,
+						u32 table_id)
+{
+	struct vrf_map_elem *me;
+	u32 key;
+
+	key = jhash_1word(table_id, HASH_INITVAL);
+	hash_for_each_possible(vmap->ht, me, hnode, key) {
+		if (me->table_id == table_id)
+			return me;
+	}
+
+	return NULL;
+}
+
+static void vrf_map_add_elem(struct vrf_map *vmap, struct vrf_map_elem *me)
+{
+	u32 table_id = me->table_id;
+	u32 key;
+
+	key = jhash_1word(table_id, HASH_INITVAL);
+	hash_add(vmap->ht, &me->hnode, key);
+}
+
+static void vrf_map_del_elem(struct vrf_map_elem *me)
+{
+	hash_del(&me->hnode);
+}
+
+static void vrf_map_lock(struct vrf_map *vmap) __acquires(&vmap->vmap_lock)
+{
+	spin_lock(&vmap->vmap_lock);
+}
+
+static void vrf_map_unlock(struct vrf_map *vmap) __releases(&vmap->vmap_lock)
+{
+	spin_unlock(&vmap->vmap_lock);
+}
+
+/* called with rtnl lock held */
+static int
+vrf_map_register_dev(struct net_device *dev, struct netlink_ext_ack *extack)
+{
+	struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
+	struct net_vrf *vrf = netdev_priv(dev);
+	struct vrf_map_elem *new_me, *me;
+	u32 table_id = vrf->tb_id;
+	bool free_new_me = false;
+	int users;
+	int res;
+
+	/* we pre-allocate elements used in the spin-locked section (so that we
+	 * keep the spinlock as short as possible).
+	 */
+	new_me = vrf_map_elem_alloc(GFP_KERNEL);
+	if (!new_me)
+		return -ENOMEM;
+
+	vrf_map_elem_init(new_me, table_id, dev->ifindex, 0);
+
+	vrf_map_lock(vmap);
+
+	me = vrf_map_lookup_elem(vmap, table_id);
+	if (!me) {
+		me = new_me;
+		vrf_map_add_elem(vmap, me);
+		goto link_vrf;
+	}
+
+	/* we already have an entry in the vrf_map, so it means there is (at
+	 * least) a vrf registered on the specific table.
+	 */
+	free_new_me = true;
+	if (vmap->strict_mode) {
+		/* vrfs cannot share the same table */
+		NL_SET_ERR_MSG(extack, "Table is used by another VRF");
+		res = -EBUSY;
+		goto unlock;
+	}
+
+link_vrf:
+	users = ++me->users;
+	if (users == 2)
+		++vmap->shared_tables;
+
+	list_add(&vrf->me_list, &me->vrf_list);
+
+	res = 0;
+
+unlock:
+	vrf_map_unlock(vmap);
+
+	/* clean-up, if needed */
+	if (free_new_me)
+		vrf_map_elem_free(new_me);
+
+	return res;
+}
+
+/* called with rtnl lock held */
+static void vrf_map_unregister_dev(struct net_device *dev)
+{
+	struct vrf_map *vmap = netns_vrf_map_by_dev(dev);
+	struct net_vrf *vrf = netdev_priv(dev);
+	u32 table_id = vrf->tb_id;
+	struct vrf_map_elem *me;
+	int users;
+
+	vrf_map_lock(vmap);
+
+	me = vrf_map_lookup_elem(vmap, table_id);
+	if (!me)
+		goto unlock;
+
+	list_del(&vrf->me_list);
+
+	users = --me->users;
+	if (users == 1) {
+		--vmap->shared_tables;
+	} else if (users == 0) {
+		vrf_map_del_elem(me);
+
+		/* no one will refer to this element anymore */
+		vrf_map_elem_free(me);
+	}
+
+unlock:
+	vrf_map_unlock(vmap);
+}
+
+/* return the vrf device index associated with the table_id */
+static int vrf_ifindex_lookup_by_table_id(struct net *net, u32 table_id)
+{
+	struct vrf_map *vmap = netns_vrf_map(net);
+	struct vrf_map_elem *me;
+	int ifindex;
+
+	vrf_map_lock(vmap);
+
+	if (!vmap->strict_mode) {
+		ifindex = -EPERM;
+		goto unlock;
+	}
+
+	me = vrf_map_lookup_elem(vmap, table_id);
+	if (!me) {
+		ifindex = -ENODEV;
+		goto unlock;
+	}
+
+	ifindex = vrf_map_elem_get_vrf_ifindex(me);
+
+unlock:
+	vrf_map_unlock(vmap);
+
+	return ifindex;
+}
+
+/* by default VRF devices do not have a qdisc and are expected
+ * to be created with only a single queue.
+ */
+static bool qdisc_tx_is_default(const struct net_device *dev)
+{
+	struct netdev_queue *txq;
+
+	if (dev->num_tx_queues > 1)
+		return false;
+
+	txq = netdev_get_tx_queue(dev, 0);
+
+	return qdisc_txq_has_no_queue(txq);
+}
+
+/* Local traffic destined to local address. Reinsert the packet to rx
+ * path, similar to loopback handling.
+ */
+static int vrf_local_xmit(struct sk_buff *skb, struct net_device *dev,
+			  struct dst_entry *dst)
+{
+	unsigned int len = skb->len;
+
+	skb_orphan(skb);
+
+	skb_dst_set(skb, dst);
+
+	/* set pkt_type to avoid skb hitting packet taps twice -
+	 * once on Tx and again in Rx processing
+	 */
+	skb->pkt_type = PACKET_LOOPBACK;
+
+	skb->protocol = eth_type_trans(skb, dev);
+
+	if (likely(__netif_rx(skb) == NET_RX_SUCCESS))
+		dev_dstats_rx_add(dev, len);
+	else
+		dev_dstats_rx_dropped(dev);
+
+	return NETDEV_TX_OK;
+}
+
+static void vrf_nf_set_untracked(struct sk_buff *skb)
+{
+	if (skb_get_nfct(skb) == 0)
+		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
+}
+
+static void vrf_nf_reset_ct(struct sk_buff *skb)
+{
+	if (skb_get_nfct(skb) == IP_CT_UNTRACKED)
+		nf_reset_ct(skb);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+static int vrf_ip6_local_out(struct net *net, struct sock *sk,
+			     struct sk_buff *skb)
+{
+	int err;
+
+	vrf_nf_reset_ct(skb);
+
+	err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net,
+		      sk, skb, NULL, skb_dst(skb)->dev, dst_output);
+
+	if (likely(err == 1))
+		err = dst_output(net, sk, skb);
+
+	return err;
+}
+
+static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
+					   struct net_device *dev)
+{
+	const struct ipv6hdr *iph;
+	struct net *net = dev_net(skb->dev);
+	struct flowi6 fl6;
+	int ret = NET_XMIT_DROP;
+	struct dst_entry *dst;
+	struct dst_entry *dst_null = &net->ipv6.ip6_null_entry->dst;
+
+	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct ipv6hdr)))
+		goto err;
+
+	iph = ipv6_hdr(skb);
+
+	memset(&fl6, 0, sizeof(fl6));
+	/* needed to match OIF rule */
+	fl6.flowi6_l3mdev = dev->ifindex;
+	fl6.flowi6_iif = LOOPBACK_IFINDEX;
+	fl6.daddr = iph->daddr;
+	fl6.saddr = iph->saddr;
+	fl6.flowlabel = ip6_flowinfo(iph);
+	fl6.flowi6_mark = skb->mark;
+	fl6.flowi6_proto = iph->nexthdr;
+
+	dst = ip6_dst_lookup_flow(net, NULL, &fl6, NULL);
+	if (IS_ERR(dst) || dst == dst_null)
+		goto err;
+
+	skb_dst_drop(skb);
+
+	/* if dst.dev is the VRF device again this is locally originated traffic
+	 * destined to a local address. Short circuit to Rx path.
+	 */
+	if (dst->dev == dev)
+		return vrf_local_xmit(skb, dev, dst);
+
+	skb_dst_set(skb, dst);
+
+	/* strip the ethernet header added for pass through VRF device */
+	__skb_pull(skb, skb_network_offset(skb));
+
+	memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
+	ret = vrf_ip6_local_out(net, skb->sk, skb);
+	if (unlikely(net_xmit_eval(ret)))
+		dev->stats.tx_errors++;
+	else
+		ret = NET_XMIT_SUCCESS;
+
+	return ret;
+err:
+	vrf_tx_error(dev, skb);
+	return NET_XMIT_DROP;
+}
+#else
+static netdev_tx_t vrf_process_v6_outbound(struct sk_buff *skb,
+					   struct net_device *dev)
+{
+	vrf_tx_error(dev, skb);
+	return NET_XMIT_DROP;
+}
+#endif
+
+/* based on ip_local_out; can't use it b/c the dst is switched pointing to us */
+static int vrf_ip_local_out(struct net *net, struct sock *sk,
+			    struct sk_buff *skb)
+{
+	int err;
+
+	vrf_nf_reset_ct(skb);
+
+	err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
+		      skb, NULL, skb_dst(skb)->dev, dst_output);
+	if (likely(err == 1))
+		err = dst_output(net, sk, skb);
+
+	return err;
+}
+
+static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
+					   struct net_device *vrf_dev)
+{
+	struct iphdr *ip4h;
+	int ret = NET_XMIT_DROP;
+	struct flowi4 fl4;
+	struct net *net = dev_net(vrf_dev);
+	struct rtable *rt;
+
+	if (!pskb_may_pull(skb, ETH_HLEN + sizeof(struct iphdr)))
+		goto err;
+
+	ip4h = ip_hdr(skb);
+
+	memset(&fl4, 0, sizeof(fl4));
+	/* needed to match OIF rule */
+	fl4.flowi4_l3mdev = vrf_dev->ifindex;
+	fl4.flowi4_iif = LOOPBACK_IFINDEX;
+	fl4.flowi4_dscp = ip4h_dscp(ip4h);
+	fl4.flowi4_flags = FLOWI_FLAG_ANYSRC;
+	fl4.flowi4_proto = ip4h->protocol;
+	fl4.daddr = ip4h->daddr;
+	fl4.saddr = ip4h->saddr;
+
+	rt = ip_route_output_flow(net, &fl4, NULL);
+	if (IS_ERR(rt))
+		goto err;
+
+	skb_dst_drop(skb);
+
+	/* if dst.dev is the VRF device again this is locally originated traffic
+	 * destined to a local address. Short circuit to Rx path.
+	 */
+	if (rt->dst.dev == vrf_dev)
+		return vrf_local_xmit(skb, vrf_dev, &rt->dst);
+
+	skb_dst_set(skb, &rt->dst);
+
+	/* strip the ethernet header added for pass through VRF device */
+	__skb_pull(skb, skb_network_offset(skb));
+
+	if (!ip4h->saddr) {
+		ip4h->saddr = inet_select_addr(skb_dst(skb)->dev, 0,
+					       RT_SCOPE_LINK);
+	}
+
+	memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
+	ret = vrf_ip_local_out(dev_net(skb_dst(skb)->dev), skb->sk, skb);
+	if (unlikely(net_xmit_eval(ret)))
+		vrf_dev->stats.tx_errors++;
+	else
+		ret = NET_XMIT_SUCCESS;
+
+out:
+	return ret;
+err:
+	vrf_tx_error(vrf_dev, skb);
+	goto out;
+}
+
+static netdev_tx_t is_ip_tx_frame(struct sk_buff *skb, struct net_device *dev)
+{
+	switch (skb->protocol) {
+	case htons(ETH_P_IP):
+		return vrf_process_v4_outbound(skb, dev);
+	case htons(ETH_P_IPV6):
+		return vrf_process_v6_outbound(skb, dev);
+	default:
+		vrf_tx_error(dev, skb);
+		return NET_XMIT_DROP;
+	}
+}
+
+static netdev_tx_t vrf_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+	unsigned int len = skb->len;
+	netdev_tx_t ret;
+
+	ret = is_ip_tx_frame(skb, dev);
+	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN))
+		dev_dstats_tx_add(dev, len);
+	else
+		dev_dstats_tx_dropped(dev);
+
+	return ret;
+}
+
+static void vrf_finish_direct(struct sk_buff *skb)
+{
+	struct net_device *vrf_dev = skb->dev;
+
+	if (!list_empty(&vrf_dev->ptype_all) &&
+	    likely(skb_headroom(skb) >= ETH_HLEN)) {
+		struct ethhdr *eth = skb_push(skb, ETH_HLEN);
+
+		ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
+		eth_zero_addr(eth->h_dest);
+		eth->h_proto = skb->protocol;
+
+		rcu_read_lock_bh();
+		dev_queue_xmit_nit(skb, vrf_dev);
+		rcu_read_unlock_bh();
+
+		skb_pull(skb, ETH_HLEN);
+	}
+
+	vrf_nf_reset_ct(skb);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/* modelled after ip6_finish_output2 */
+static int vrf_finish_output6(struct net *net, struct sock *sk,
+			      struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct net_device *dev = dst->dev;
+	const struct in6_addr *nexthop;
+	struct neighbour *neigh;
+	int ret;
+
+	vrf_nf_reset_ct(skb);
+
+	skb->protocol = htons(ETH_P_IPV6);
+	skb->dev = dev;
+
+	rcu_read_lock();
+	nexthop = rt6_nexthop(dst_rt6_info(dst), &ipv6_hdr(skb)->daddr);
+	neigh = __ipv6_neigh_lookup_noref(dst->dev, nexthop);
+	if (unlikely(!neigh))
+		neigh = __neigh_create(&nd_tbl, nexthop, dst->dev, false);
+	if (!IS_ERR(neigh)) {
+		sock_confirm_neigh(skb, neigh);
+		ret = neigh_output(neigh, skb, false);
+		rcu_read_unlock();
+		return ret;
+	}
+	rcu_read_unlock();
+
+	IP6_INC_STATS(dev_net(dst->dev),
+		      ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);
+	kfree_skb(skb);
+	return -EINVAL;
+}
+
+/* modelled after ip6_output */
+static int vrf_output6(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	return NF_HOOK_COND(NFPROTO_IPV6, NF_INET_POST_ROUTING,
+			    net, sk, skb, NULL, skb_dst(skb)->dev,
+			    vrf_finish_output6,
+			    !(IP6CB(skb)->flags & IP6SKB_REROUTED));
+}
+
+/* set dst on skb to send packet to us via dev_xmit path. Allows
+ * packet to go through device based features such as qdisc, netfilter
+ * hooks and packet sockets with skb->dev set to vrf device.
+ */
+static struct sk_buff *vrf_ip6_out_redirect(struct net_device *vrf_dev,
+					    struct sk_buff *skb)
+{
+	struct net_vrf *vrf = netdev_priv(vrf_dev);
+	struct rt6_info *rt6;
+
+	rt6 = vrf->rt6;
+	dst_hold(&rt6->dst);
+
+	skb_dst_drop(skb);
+	skb_dst_set(skb, &rt6->dst);
+
+	return skb;
+}
+
+static int vrf_output6_direct_finish(struct net *net, struct sock *sk,
+				     struct sk_buff *skb)
+{
+	vrf_finish_direct(skb);
+
+	return vrf_ip6_local_out(net, sk, skb);
+}
+
+static int vrf_output6_direct(struct net *net, struct sock *sk,
+			      struct sk_buff *skb)
+{
+	int err = 1;
+
+	skb->protocol = htons(ETH_P_IPV6);
+
+	if (!(IPCB(skb)->flags & IPSKB_REROUTED))
+		err = nf_hook(NFPROTO_IPV6, NF_INET_POST_ROUTING, net, sk, skb,
+			      NULL, skb->dev, vrf_output6_direct_finish);
+
+	if (likely(err == 1))
+		vrf_finish_direct(skb);
+
+	return err;
+}
+
+static int vrf_ip6_out_direct_finish(struct net *net, struct sock *sk,
+				     struct sk_buff *skb)
+{
+	int err;
+
+	err = vrf_output6_direct(net, sk, skb);
+	if (likely(err == 1))
+		err = vrf_ip6_local_out(net, sk, skb);
+
+	return err;
+}
+
+static struct sk_buff *vrf_ip6_out_direct(struct net_device *vrf_dev,
+					  struct sock *sk,
+					  struct sk_buff *skb)
+{
+	struct net *net = dev_net(vrf_dev);
+	int err;
+
+	skb->dev = vrf_dev;
+
+	err = nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk,
+		      skb, NULL, vrf_dev, vrf_ip6_out_direct_finish);
+
+	if (likely(err == 1))
+		err = vrf_output6_direct(net, sk, skb);
+
+	if (likely(err == 1))
+		return skb;
+
+	return NULL;
+}
+
+static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
+				   struct sock *sk,
+				   struct sk_buff *skb)
+{
+	/* don't divert link scope packets */
+	if (rt6_need_strict(&ipv6_hdr(skb)->daddr))
+		return skb;
+
+	vrf_nf_set_untracked(skb);
+
+	if (qdisc_tx_is_default(vrf_dev) ||
+	    IP6CB(skb)->flags & IP6SKB_XFRM_TRANSFORMED)
+		return vrf_ip6_out_direct(vrf_dev, sk, skb);
+
+	return vrf_ip6_out_redirect(vrf_dev, skb);
+}
+
+/* holding rtnl */
+static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
+{
+	struct rt6_info *rt6 = vrf->rt6;
+
+	if (rt6) {
+		dst_dev_put(&rt6->dst);
+		dst_release(&rt6->dst);
+	}
+}
+
+static int vrf_rt6_create(struct net_device *dev)
+{
+	int flags = DST_NOPOLICY | DST_NOXFRM;
+	struct net_vrf *vrf = netdev_priv(dev);
+	struct net *net = dev_net(dev);
+	struct rt6_info *rt6;
+	int rc = -ENOMEM;
+
+	/* IPv6 can be CONFIG enabled and then disabled runtime */
+	if (!ipv6_mod_enabled())
+		return 0;
+
+	vrf->fib6_table = fib6_new_table(net, vrf->tb_id);
+	if (!vrf->fib6_table)
+		goto out;
+
+	/* create a dst for routing packets out a VRF device */
+	rt6 = ip6_dst_alloc(net, dev, flags);
+	if (!rt6)
+		goto out;
+
+	rt6->dst.output	= vrf_output6;
+
+	vrf->rt6 = rt6;
+
+	rc = 0;
+out:
+	return rc;
+}
+#else
+static struct sk_buff *vrf_ip6_out(struct net_device *vrf_dev,
+				   struct sock *sk,
+				   struct sk_buff *skb)
+{
+	return skb;
+}
+
+static void vrf_rt6_release(struct net_device *dev, struct net_vrf *vrf)
+{
+}
+
+static int vrf_rt6_create(struct net_device *dev)
+{
+	return 0;
+}
+#endif
+
+/* modelled after ip_finish_output2 */
+static int vrf_finish_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct rtable *rt = dst_rtable(dst);
+	struct net_device *dev = dst->dev;
+	unsigned int hh_len = LL_RESERVED_SPACE(dev);
+	struct neighbour *neigh;
+	bool is_v6gw = false;
+
+	vrf_nf_reset_ct(skb);
+
+	/* Be paranoid, rather than too clever. */
+	if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
+		skb = skb_expand_head(skb, hh_len);
+		if (!skb) {
+			dev->stats.tx_errors++;
+			return -ENOMEM;
+		}
+	}
+
+	rcu_read_lock();
+
+	neigh = ip_neigh_for_gw(rt, skb, &is_v6gw);
+	if (!IS_ERR(neigh)) {
+		int ret;
+
+		sock_confirm_neigh(skb, neigh);
+		/* if crossing protocols, can not use the cached header */
+		ret = neigh_output(neigh, skb, is_v6gw);
+		rcu_read_unlock();
+		return ret;
+	}
+
+	rcu_read_unlock();
+	vrf_tx_error(skb->dev, skb);
+	return -EINVAL;
+}
+
+static int vrf_output(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	struct net_device *dev = skb_dst(skb)->dev;
+
+	IP_UPD_PO_STATS(net, IPSTATS_MIB_OUT, skb->len);
+
+	skb->dev = dev;
+	skb->protocol = htons(ETH_P_IP);
+
+	return NF_HOOK_COND(NFPROTO_IPV4, NF_INET_POST_ROUTING,
+			    net, sk, skb, NULL, dev,
+			    vrf_finish_output,
+			    !(IPCB(skb)->flags & IPSKB_REROUTED));
+}
+
+/* set dst on skb to send packet to us via dev_xmit path. Allows
+ * packet to go through device based features such as qdisc, netfilter
+ * hooks and packet sockets with skb->dev set to vrf device.
+ */
+static struct sk_buff *vrf_ip_out_redirect(struct net_device *vrf_dev,
+					   struct sk_buff *skb)
+{
+	struct net_vrf *vrf = netdev_priv(vrf_dev);
+	struct rtable *rth;
+
+	rth = vrf->rth;
+	dst_hold(&rth->dst);
+
+	skb_dst_drop(skb);
+	skb_dst_set(skb, &rth->dst);
+
+	return skb;
+}
+
+static int vrf_output_direct_finish(struct net *net, struct sock *sk,
+				    struct sk_buff *skb)
+{
+	vrf_finish_direct(skb);
+
+	return vrf_ip_local_out(net, sk, skb);
+}
+
+static int vrf_output_direct(struct net *net, struct sock *sk,
+			     struct sk_buff *skb)
+{
+	int err = 1;
+
+	skb->protocol = htons(ETH_P_IP);
+
+	if (!(IPCB(skb)->flags & IPSKB_REROUTED))
+		err = nf_hook(NFPROTO_IPV4, NF_INET_POST_ROUTING, net, sk, skb,
+			      NULL, skb->dev, vrf_output_direct_finish);
+
+	if (likely(err == 1))
+		vrf_finish_direct(skb);
+
+	return err;
+}
+
+static int vrf_ip_out_direct_finish(struct net *net, struct sock *sk,
+				    struct sk_buff *skb)
+{
+	int err;
+
+	err = vrf_output_direct(net, sk, skb);
+	if (likely(err == 1))
+		err = vrf_ip_local_out(net, sk, skb);
+
+	return err;
+}
+
+static struct sk_buff *vrf_ip_out_direct(struct net_device *vrf_dev,
+					 struct sock *sk,
+					 struct sk_buff *skb)
+{
+	struct net *net = dev_net(vrf_dev);
+	int err;
+
+	skb->dev = vrf_dev;
+
+	err = nf_hook(NFPROTO_IPV4, NF_INET_LOCAL_OUT, net, sk,
+		      skb, NULL, vrf_dev, vrf_ip_out_direct_finish);
+
+	if (likely(err == 1))
+		err = vrf_output_direct(net, sk, skb);
+
+	if (likely(err == 1))
+		return skb;
+
+	return NULL;
+}
+
+static struct sk_buff *vrf_ip_out(struct net_device *vrf_dev,
+				  struct sock *sk,
+				  struct sk_buff *skb)
+{
+	/* don't divert multicast or local broadcast */
+	if (ipv4_is_multicast(ip_hdr(skb)->daddr) ||
+	    ipv4_is_lbcast(ip_hdr(skb)->daddr))
+		return skb;
+
+	vrf_nf_set_untracked(skb);
+
+	if (qdisc_tx_is_default(vrf_dev) ||
+	    IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED)
+		return vrf_ip_out_direct(vrf_dev, sk, skb);
+
+	return vrf_ip_out_redirect(vrf_dev, skb);
+}
+
+/* called with rcu lock held */
+static struct sk_buff *vrf_l3_out(struct net_device *vrf_dev,
+				  struct sock *sk,
+				  struct sk_buff *skb,
+				  u16 proto)
+{
+	switch (proto) {
+	case AF_INET:
+		return vrf_ip_out(vrf_dev, sk, skb);
+	case AF_INET6:
+		return vrf_ip6_out(vrf_dev, sk, skb);
+	}
+
+	return skb;
+}
+
+/* holding rtnl */
+static void vrf_rtable_release(struct net_device *dev, struct net_vrf *vrf)
+{
+	struct rtable *rth = vrf->rth;
+
+	dst_dev_put(&rth->dst);
+	dst_release(&rth->dst);
+}
+
+static int vrf_rtable_create(struct net_device *dev)
+{
+	struct net_vrf *vrf = netdev_priv(dev);
+	struct rtable *rth;
+
+	if (!fib_new_table(dev_net(dev), vrf->tb_id))
+		return -ENOMEM;
+
+	/* create a dst for routing packets out through a VRF device */
+	rth = rt_dst_alloc(dev, 0, RTN_UNICAST, 1);
+	if (!rth)
+		return -ENOMEM;
+
+	rth->dst.output	= vrf_output;
+
+	vrf->rth = rth;
+
+	return 0;
+}
+
+/**************************** device handling ********************/
+
+/* cycle interface to flush neighbor cache and move routes across tables */
+static void cycle_netdev(struct net_device *dev,
+			 struct netlink_ext_ack *extack)
+{
+	unsigned int flags = dev->flags;
+	int ret;
+
+	if (!netif_running(dev))
+		return;
+
+	ret = dev_change_flags(dev, flags & ~IFF_UP, extack);
+	if (ret >= 0)
+		ret = dev_change_flags(dev, flags, extack);
+
+	if (ret < 0) {
+		netdev_err(dev,
+			   "Failed to cycle device %s; route tables might be wrong!\n",
+			   dev->name);
+	}
+}
+
+static int do_vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
+			    struct netlink_ext_ack *extack)
+{
+	int ret;
+
+	/* do not allow loopback device to be enslaved to a VRF.
+	 * The vrf device acts as the loopback for the vrf.
+	 */
+	if (port_dev == dev_net(dev)->loopback_dev) {
+		NL_SET_ERR_MSG(extack,
+			       "Can not enslave loopback device to a VRF");
+		return -EOPNOTSUPP;
+	}
+
+	port_dev->priv_flags |= IFF_L3MDEV_SLAVE;
+	ret = netdev_master_upper_dev_link(port_dev, dev, NULL, NULL, extack);
+	if (ret < 0)
+		goto err;
+
+	cycle_netdev(port_dev, extack);
+
+	return 0;
+
+err:
+	port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
+	synchronize_net();
+	return ret;
+}
+
+static int vrf_add_slave(struct net_device *dev, struct net_device *port_dev,
+			 struct netlink_ext_ack *extack)
+{
+	if (netif_is_l3_master(port_dev)) {
+		NL_SET_ERR_MSG(extack,
+			       "Can not enslave an L3 master device to a VRF");
+		return -EINVAL;
+	}
+
+	if (netif_is_l3_slave(port_dev))
+		return -EINVAL;
+
+	return do_vrf_add_slave(dev, port_dev, extack);
+}
+
+/* inverse of do_vrf_add_slave */
+static int do_vrf_del_slave(struct net_device *dev, struct net_device *port_dev,
+			    bool needs_sync)
+{
+	netdev_upper_dev_unlink(port_dev, dev);
+	port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
+	/* Make sure that concurrent RCU readers that identified the device
+	 * as a VRF port see a VRF master or no master at all.
+	 */
+	if (needs_sync)
+		synchronize_net();
+
+	cycle_netdev(port_dev, NULL);
+
+	return 0;
+}
+
+static int vrf_del_slave(struct net_device *dev, struct net_device *port_dev)
+{
+	return do_vrf_del_slave(dev, port_dev, true);
+}
+
+static void vrf_dev_uninit(struct net_device *dev)
+{
+	struct net_vrf *vrf = netdev_priv(dev);
+
+	vrf_rtable_release(dev, vrf);
+	vrf_rt6_release(dev, vrf);
+}
+
+static int vrf_dev_init(struct net_device *dev)
+{
+	struct net_vrf *vrf = netdev_priv(dev);
+
+	/* create the default dst which points back to us */
+	if (vrf_rtable_create(dev) != 0)
+		goto out_nomem;
+
+	if (vrf_rt6_create(dev) != 0)
+		goto out_rth;
+
+	dev->flags = IFF_MASTER | IFF_NOARP;
+
+	/* similarly, oper state is irrelevant; set to up to avoid confusion */
+	dev->operstate = IF_OPER_UP;
+	netdev_lockdep_set_classes(dev);
+	return 0;
+
+out_rth:
+	vrf_rtable_release(dev, vrf);
+out_nomem:
+	return -ENOMEM;
+}
+
+static const struct net_device_ops vrf_netdev_ops = {
+	.ndo_init		= vrf_dev_init,
+	.ndo_uninit		= vrf_dev_uninit,
+	.ndo_start_xmit		= vrf_xmit,
+	.ndo_set_mac_address	= eth_mac_addr,
+	.ndo_add_slave		= vrf_add_slave,
+	.ndo_del_slave		= vrf_del_slave,
+};
+
+static u32 vrf_fib_table(const struct net_device *dev)
+{
+	struct net_vrf *vrf = netdev_priv(dev);
+
+	return vrf->tb_id;
+}
+
+static int vrf_rcv_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	kfree_skb(skb);
+	return 0;
+}
+
+static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook,
+				      struct sk_buff *skb,
+				      struct net_device *dev)
+{
+	struct net *net = dev_net(dev);
+
+	if (nf_hook(pf, hook, net, NULL, skb, dev, NULL, vrf_rcv_finish) != 1)
+		skb = NULL;    /* kfree_skb(skb) handled by nf code */
+
+	return skb;
+}
+
+static int vrf_prepare_mac_header(struct sk_buff *skb,
+				  struct net_device *vrf_dev, u16 proto)
+{
+	struct ethhdr *eth;
+	int err;
+
+	/* in general, we do not know if there is enough space in the head of
+	 * the packet for hosting the mac header.
+	 */
+	err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));
+	if (unlikely(err))
+		/* no space in the skb head */
+		return -ENOBUFS;
+
+	__skb_push(skb, ETH_HLEN);
+	eth = (struct ethhdr *)skb->data;
+
+	skb_reset_mac_header(skb);
+	skb_reset_mac_len(skb);
+
+	/* we set the ethernet destination and the source addresses to the
+	 * address of the VRF device.
+	 */
+	ether_addr_copy(eth->h_dest, vrf_dev->dev_addr);
+	ether_addr_copy(eth->h_source, vrf_dev->dev_addr);
+	eth->h_proto = htons(proto);
+
+	/* the destination address of the Ethernet frame corresponds to the
+	 * address set on the VRF interface; therefore, the packet is intended
+	 * to be processed locally.
+	 */
+	skb->protocol = eth->h_proto;
+	skb->pkt_type = PACKET_HOST;
+
+	skb_postpush_rcsum(skb, skb->data, ETH_HLEN);
+
+	skb_pull_inline(skb, ETH_HLEN);
+
+	return 0;
+}
+
+/* prepare and add the mac header to the packet if it was not set previously.
+ * In this way, packet sniffers such as tcpdump can parse the packet correctly.
+ * If the mac header was already set, the original mac header is left
+ * untouched and the function returns immediately.
+ */
+static int vrf_add_mac_header_if_unset(struct sk_buff *skb,
+				       struct net_device *vrf_dev,
+				       u16 proto, struct net_device *orig_dev)
+{
+	if (skb_mac_header_was_set(skb) && dev_has_header(orig_dev))
+		return 0;
+
+	return vrf_prepare_mac_header(skb, vrf_dev, proto);
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/* neighbor handling is done with actual device; do not want
+ * to flip skb->dev for those ndisc packets. This really fails
+ * for multiple next protocols (e.g., NEXTHDR_HOP). But it is
+ * a start.
+ */
+static bool ipv6_ndisc_frame(const struct sk_buff *skb)
+{
+	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	bool rc = false;
+
+	if (iph->nexthdr == NEXTHDR_ICMP) {
+		const struct icmp6hdr *icmph;
+		struct icmp6hdr _icmph;
+
+		icmph = skb_header_pointer(skb, sizeof(*iph),
+					   sizeof(_icmph), &_icmph);
+		if (!icmph)
+			goto out;
+
+		switch (icmph->icmp6_type) {
+		case NDISC_ROUTER_SOLICITATION:
+		case NDISC_ROUTER_ADVERTISEMENT:
+		case NDISC_NEIGHBOUR_SOLICITATION:
+		case NDISC_NEIGHBOUR_ADVERTISEMENT:
+		case NDISC_REDIRECT:
+			rc = true;
+			break;
+		}
+	}
+
+out:
+	return rc;
+}
+
+static struct rt6_info *vrf_ip6_route_lookup(struct net *net,
+					     const struct net_device *dev,
+					     struct flowi6 *fl6,
+					     int ifindex,
+					     const struct sk_buff *skb,
+					     int flags)
+{
+	struct net_vrf *vrf = netdev_priv(dev);
+
+	return ip6_pol_route(net, vrf->fib6_table, ifindex, fl6, skb, flags);
+}
+
+static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev,
+			      int ifindex)
+{
+	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	struct flowi6 fl6 = {
+		.flowi6_iif     = ifindex,
+		.flowi6_mark    = skb->mark,
+		.flowi6_proto   = iph->nexthdr,
+		.daddr          = iph->daddr,
+		.saddr          = iph->saddr,
+		.flowlabel      = ip6_flowinfo(iph),
+	};
+	struct net *net = dev_net(vrf_dev);
+	struct rt6_info *rt6;
+
+	skb_dst_drop(skb);
+
+	rt6 = vrf_ip6_route_lookup(net, vrf_dev, &fl6, ifindex, skb,
+				   RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_IFACE);
+	if (unlikely(!rt6))
+		return;
+
+	if (unlikely(&rt6->dst == &net->ipv6.ip6_null_entry->dst))
+		return;
+
+	skb_dst_set(skb, &rt6->dst);
+}
+
+static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
+				   struct sk_buff *skb)
+{
+	int orig_iif = skb->skb_iif;
+	bool need_strict = rt6_need_strict(&ipv6_hdr(skb)->daddr);
+	bool is_ndisc = ipv6_ndisc_frame(skb);
+
+	/* loopback, multicast & non-ND link-local traffic; do not push through
+	 * packet taps again. Reset pkt_type for upper layers to process skb.
+	 * For non-loopback strict packets, determine the dst using the original
+	 * ifindex.
+	 */
+	if (skb->pkt_type == PACKET_LOOPBACK || (need_strict && !is_ndisc)) {
+		skb->dev = vrf_dev;
+		skb->skb_iif = vrf_dev->ifindex;
+		IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
+
+		if (skb->pkt_type == PACKET_LOOPBACK)
+			skb->pkt_type = PACKET_HOST;
+		else
+			vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
+
+		goto out;
+	}
+
+	/* if packet is NDISC then keep the ingress interface */
+	if (!is_ndisc) {
+		struct net_device *orig_dev = skb->dev;
+
+		dev_dstats_rx_add(vrf_dev, skb->len);
+		skb->dev = vrf_dev;
+		skb->skb_iif = vrf_dev->ifindex;
+
+		if (!list_empty(&vrf_dev->ptype_all)) {
+			int err;
+
+			err = vrf_add_mac_header_if_unset(skb, vrf_dev,
+							  ETH_P_IPV6,
+							  orig_dev);
+			if (likely(!err)) {
+				skb_push(skb, skb->mac_len);
+				dev_queue_xmit_nit(skb, vrf_dev);
+				skb_pull(skb, skb->mac_len);
+			}
+		}
+
+		IP6CB(skb)->flags |= IP6SKB_L3SLAVE;
+	}
+
+	if (need_strict)
+		vrf_ip6_input_dst(skb, vrf_dev, orig_iif);
+
+	skb = vrf_rcv_nfhook(NFPROTO_IPV6, NF_INET_PRE_ROUTING, skb, vrf_dev);
+out:
+	return skb;
+}
+
+#else
+static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
+				   struct sk_buff *skb)
+{
+	return skb;
+}
+#endif
+
+static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
+				  struct sk_buff *skb)
+{
+	struct net_device *orig_dev = skb->dev;
+
+	skb->dev = vrf_dev;
+	skb->skb_iif = vrf_dev->ifindex;
+	IPCB(skb)->flags |= IPSKB_L3SLAVE;
+
+	if (ipv4_is_multicast(ip_hdr(skb)->daddr))
+		goto out;
+
+	/* loopback traffic; do not push through packet taps again.
+	 * Reset pkt_type for upper layers to process skb
+	 */
+	if (skb->pkt_type == PACKET_LOOPBACK) {
+		skb->pkt_type = PACKET_HOST;
+		goto out;
+	}
+
+	dev_dstats_rx_add(vrf_dev, skb->len);
+
+	if (!list_empty(&vrf_dev->ptype_all)) {
+		int err;
+
+		err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP,
+						  orig_dev);
+		if (likely(!err)) {
+			skb_push(skb, skb->mac_len);
+			dev_queue_xmit_nit(skb, vrf_dev);
+			skb_pull(skb, skb->mac_len);
+		}
+	}
+
+	skb = vrf_rcv_nfhook(NFPROTO_IPV4, NF_INET_PRE_ROUTING, skb, vrf_dev);
+out:
+	return skb;
+}
+
+/* called with rcu lock held */
+static struct sk_buff *vrf_l3_rcv(struct net_device *vrf_dev,
+				  struct sk_buff *skb,
+				  u16 proto)
+{
+	switch (proto) {
+	case AF_INET:
+		return vrf_ip_rcv(vrf_dev, skb);
+	case AF_INET6:
+		return vrf_ip6_rcv(vrf_dev, skb);
+	}
+
+	return skb;
+}
+
+#if IS_ENABLED(CONFIG_IPV6)
+/* send to link-local or multicast address via interface enslaved to
+ * VRF device. Force lookup to VRF table without changing flow struct
+ * Note: Caller to this function must hold rcu_read_lock() and no refcnt
+ * is taken on the dst by this function.
+ */
+static struct dst_entry *vrf_link_scope_lookup(const struct net_device *dev,
+					      struct flowi6 *fl6)
+{
+	struct net *net = dev_net(dev);
+	int flags = RT6_LOOKUP_F_IFACE | RT6_LOOKUP_F_DST_NOREF;
+	struct dst_entry *dst = NULL;
+	struct rt6_info *rt;
+
+	/* VRF device does not have a link-local address and
+	 * sending packets to link-local or mcast addresses over
+	 * a VRF device does not make sense
+	 */
+	if (fl6->flowi6_oif == dev->ifindex) {
+		dst = &net->ipv6.ip6_null_entry->dst;
+		return dst;
+	}
+
+	if (!ipv6_addr_any(&fl6->saddr))
+		flags |= RT6_LOOKUP_F_HAS_SADDR;
+
+	rt = vrf_ip6_route_lookup(net, dev, fl6, fl6->flowi6_oif, NULL, flags);
+	if (rt)
+		dst = &rt->dst;
+
+	return dst;
+}
+#endif
+
+static const struct l3mdev_ops vrf_l3mdev_ops = {
+	.l3mdev_fib_table	= vrf_fib_table,
+	.l3mdev_l3_rcv		= vrf_l3_rcv,
+	.l3mdev_l3_out		= vrf_l3_out,
+#if IS_ENABLED(CONFIG_IPV6)
+	.l3mdev_link_scope_lookup = vrf_link_scope_lookup,
+#endif
+};
+
+static void vrf_get_drvinfo(struct net_device *dev,
+			    struct ethtool_drvinfo *info)
+{
+	strscpy(info->driver, DRV_NAME, sizeof(info->driver));
+	strscpy(info->version, DRV_VERSION, sizeof(info->version));
+}
+
+static const struct ethtool_ops vrf_ethtool_ops = {
+	.get_drvinfo	= vrf_get_drvinfo,
+};
+
+static inline size_t vrf_fib_rule_nl_size(void)
+{
+	size_t sz;
+
+	sz  = NLMSG_ALIGN(sizeof(struct fib_rule_hdr));
+	sz += nla_total_size(sizeof(u8));	/* FRA_L3MDEV */
+	sz += nla_total_size(sizeof(u32));	/* FRA_PRIORITY */
+	sz += nla_total_size(sizeof(u8));       /* FRA_PROTOCOL */
+
+	return sz;
+}
+
+static int vrf_fib_rule(const struct net_device *dev, __u8 family, bool add_it)
+{
+	struct fib_rule_hdr *frh;
+	struct nlmsghdr *nlh;
+	struct sk_buff *skb;
+	int err;
+
+	if ((family == AF_INET6 || family == RTNL_FAMILY_IP6MR) &&
+	    !ipv6_mod_enabled())
+		return 0;
+
+	skb = nlmsg_new(vrf_fib_rule_nl_size(), GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	nlh = nlmsg_put(skb, 0, 0, 0, sizeof(*frh), 0);
+	if (!nlh)
+		goto nla_put_failure;
+
+	/* rule only needs to appear once */
+	nlh->nlmsg_flags |= NLM_F_EXCL;
+
+	frh = nlmsg_data(nlh);
+	memset(frh, 0, sizeof(*frh));
+	frh->family = family;
+	frh->action = FR_ACT_TO_TBL;
+
+	if (nla_put_u8(skb, FRA_PROTOCOL, RTPROT_KERNEL))
+		goto nla_put_failure;
+
+	if (nla_put_u8(skb, FRA_L3MDEV, 1))
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, FRA_PRIORITY, FIB_RULE_PREF))
+		goto nla_put_failure;
+
+	nlmsg_end(skb, nlh);
+
+	if (add_it) {
+		err = fib_newrule(dev_net(dev), skb, nlh, NULL, true);
+		if (err == -EEXIST)
+			err = 0;
+	} else {
+		err = fib_delrule(dev_net(dev), skb, nlh, NULL, true);
+		if (err == -ENOENT)
+			err = 0;
+	}
+	nlmsg_free(skb);
+
+	return err;
+
+nla_put_failure:
+	nlmsg_free(skb);
+
+	return -EMSGSIZE;
+}
+
+static int vrf_add_fib_rules(const struct net_device *dev)
+{
+	int err;
+
+	err = vrf_fib_rule(dev, AF_INET,  true);
+	if (err < 0)
+		goto out_err;
+
+	err = vrf_fib_rule(dev, AF_INET6, true);
+	if (err < 0)
+		goto ipv6_err;
+
+#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
+	err = vrf_fib_rule(dev, RTNL_FAMILY_IPMR, true);
+	if (err < 0)
+		goto ipmr_err;
+#endif
+
+#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
+	err = vrf_fib_rule(dev, RTNL_FAMILY_IP6MR, true);
+	if (err < 0)
+		goto ip6mr_err;
+#endif
+
+	return 0;
+
+#if IS_ENABLED(CONFIG_IPV6_MROUTE_MULTIPLE_TABLES)
+ip6mr_err:
+	vrf_fib_rule(dev, RTNL_FAMILY_IPMR,  false);
+#endif
+
+#if IS_ENABLED(CONFIG_IP_MROUTE_MULTIPLE_TABLES)
+ipmr_err:
+	vrf_fib_rule(dev, AF_INET6,  false);
+#endif
+
+ipv6_err:
+	vrf_fib_rule(dev, AF_INET,  false);
+
+out_err:
+	netdev_err(dev, "Failed to add FIB rules.\n");
+	return err;
+}
+
+static void vrf_setup(struct net_device *dev)
+{
+	ether_setup(dev);
+
+	/* Initialize the device structure. */
+	dev->netdev_ops = &vrf_netdev_ops;
+	dev->l3mdev_ops = &vrf_l3mdev_ops;
+	dev->ethtool_ops = &vrf_ethtool_ops;
+	dev->needs_free_netdev = true;
+
+	/* Fill in device structure with ethernet-generic values. */
+	eth_hw_addr_random(dev);
+
+	/* don't acquire vrf device's netif_tx_lock when transmitting */
+	dev->lltx = true;
+
+	/* don't allow vrf devices to change network namespaces. */
+	dev->netns_immutable = true;
+
+	/* does not make sense for a VLAN to be added to a vrf device */
+	dev->features   |= NETIF_F_VLAN_CHALLENGED;
+
+	/* enable offload features */
+	dev->features   |= NETIF_F_GSO_SOFTWARE;
+	dev->features   |= NETIF_F_RXCSUM | NETIF_F_HW_CSUM | NETIF_F_SCTP_CRC;
+	dev->features   |= NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA;
+
+	dev->hw_features = dev->features;
+	dev->hw_enc_features = dev->features;
+
+	/* default to no qdisc; user can add if desired */
+	dev->priv_flags |= IFF_NO_QUEUE;
+	dev->priv_flags |= IFF_NO_RX_HANDLER;
+	dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
+
+	/* VRF devices do not care about MTU, but if the MTU is set
+	 * too low then the ipv4 and ipv6 protocols are disabled
+	 * which breaks networking.
+	 */
+	dev->min_mtu = IPV6_MIN_MTU;
+	dev->max_mtu = IP6_MAX_MTU;
+	dev->mtu = dev->max_mtu;
+
+	dev->pcpu_stat_type = NETDEV_PCPU_STAT_DSTATS;
+}
+
+static int vrf_validate(struct nlattr *tb[], struct nlattr *data[],
+			struct netlink_ext_ack *extack)
+{
+	if (tb[IFLA_ADDRESS]) {
+		if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
+			NL_SET_ERR_MSG(extack, "Invalid hardware address");
+			return -EINVAL;
+		}
+		if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
+			NL_SET_ERR_MSG(extack, "Invalid hardware address");
+			return -EADDRNOTAVAIL;
+		}
+	}
+	return 0;
+}
+
+static void vrf_dellink(struct net_device *dev, struct list_head *head)
+{
+	struct net_device *port_dev;
+	struct list_head *iter;
+
+	netdev_for_each_lower_dev(dev, port_dev, iter)
+		do_vrf_del_slave(dev, port_dev, false);
+
+	vrf_map_unregister_dev(dev);
+
+	unregister_netdevice_queue(dev, head);
+}
+
+static int vrf_newlink(struct net_device *dev,
+		       struct rtnl_newlink_params *params,
+		       struct netlink_ext_ack *extack)
+{
+	struct net_vrf *vrf = netdev_priv(dev);
+	struct nlattr **data = params->data;
+	struct netns_vrf *nn_vrf;
+	bool *add_fib_rules;
+	struct net *net;
+	int err;
+
+	if (!data || !data[IFLA_VRF_TABLE]) {
+		NL_SET_ERR_MSG(extack, "VRF table id is missing");
+		return -EINVAL;
+	}
+
+	vrf->tb_id = nla_get_u32(data[IFLA_VRF_TABLE]);
+	if (vrf->tb_id == RT_TABLE_UNSPEC) {
+		NL_SET_ERR_MSG_ATTR(extack, data[IFLA_VRF_TABLE],
+				    "Invalid VRF table id");
+		return -EINVAL;
+	}
+
+	dev->priv_flags |= IFF_L3MDEV_MASTER;
+
+	err = register_netdevice(dev);
+	if (err)
+		goto out;
+
+	/* mapping between table_id and vrf;
+	 * note: such binding could not be done in the dev init function
+	 * because dev->ifindex id is not available yet.
+	 */
+	vrf->ifindex = dev->ifindex;
+
+	err = vrf_map_register_dev(dev, extack);
+	if (err) {
+		unregister_netdevice(dev);
+		goto out;
+	}
+
+	net = dev_net(dev);
+	nn_vrf = net_generic(net, vrf_net_id);
+
+	add_fib_rules = &nn_vrf->add_fib_rules;
+	if (*add_fib_rules) {
+		err = vrf_add_fib_rules(dev);
+		if (err) {
+			vrf_map_unregister_dev(dev);
+			unregister_netdevice(dev);
+			goto out;
+		}
+		*add_fib_rules = false;
+	}
+
+out:
+	return err;
+}
+
+static size_t vrf_nl_getsize(const struct net_device *dev)
+{
+	return nla_total_size(sizeof(u32));  /* IFLA_VRF_TABLE */
+}
+
+static int vrf_fillinfo(struct sk_buff *skb,
+			const struct net_device *dev)
+{
+	struct net_vrf *vrf = netdev_priv(dev);
+
+	return nla_put_u32(skb, IFLA_VRF_TABLE, vrf->tb_id);
+}
+
+static size_t vrf_get_slave_size(const struct net_device *bond_dev,
+				 const struct net_device *slave_dev)
+{
+	return nla_total_size(sizeof(u32));  /* IFLA_VRF_PORT_TABLE */
+}
+
+static int vrf_fill_slave_info(struct sk_buff *skb,
+			       const struct net_device *vrf_dev,
+			       const struct net_device *slave_dev)
+{
+	struct net_vrf *vrf = netdev_priv(vrf_dev);
+
+	if (nla_put_u32(skb, IFLA_VRF_PORT_TABLE, vrf->tb_id))
+		return -EMSGSIZE;
+
+	return 0;
+}
+
+static const struct nla_policy vrf_nl_policy[IFLA_VRF_MAX + 1] = {
+	[IFLA_VRF_TABLE] = { .type = NLA_U32 },
+};
+
+static struct rtnl_link_ops vrf_link_ops __read_mostly = {
+	.kind		= DRV_NAME,
+	.priv_size	= sizeof(struct net_vrf),
+
+	.get_size	= vrf_nl_getsize,
+	.policy		= vrf_nl_policy,
+	.validate	= vrf_validate,
+	.fill_info	= vrf_fillinfo,
+
+	.get_slave_size  = vrf_get_slave_size,
+	.fill_slave_info = vrf_fill_slave_info,
+
+	.newlink	= vrf_newlink,
+	.dellink	= vrf_dellink,
+	.setup		= vrf_setup,
+	.maxtype	= IFLA_VRF_MAX,
+};
+
+static int vrf_device_event(struct notifier_block *unused,
+			    unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+
+	/* only care about unregister events to drop slave references */
+	if (event == NETDEV_UNREGISTER) {
+		struct net_device *vrf_dev;
+
+		if (!netif_is_l3_slave(dev))
+			goto out;
+
+		vrf_dev = netdev_master_upper_dev_get(dev);
+		do_vrf_del_slave(vrf_dev, dev, false);
+	}
+out:
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block vrf_notifier_block __read_mostly = {
+	.notifier_call = vrf_device_event,
+};
+
+static int vrf_map_init(struct vrf_map *vmap)
+{
+	spin_lock_init(&vmap->vmap_lock);
+	hash_init(vmap->ht);
+
+	vmap->strict_mode = false;
+
+	return 0;
+}
+
+#ifdef CONFIG_SYSCTL
+static bool vrf_strict_mode(struct vrf_map *vmap)
+{
+	bool strict_mode;
+
+	vrf_map_lock(vmap);
+	strict_mode = vmap->strict_mode;
+	vrf_map_unlock(vmap);
+
+	return strict_mode;
+}
+
+static int vrf_strict_mode_change(struct vrf_map *vmap, bool new_mode)
+{
+	bool *cur_mode;
+	int res = 0;
+
+	vrf_map_lock(vmap);
+
+	cur_mode = &vmap->strict_mode;
+	if (*cur_mode == new_mode)
+		goto unlock;
+
+	if (*cur_mode) {
+		/* disable strict mode */
+		*cur_mode = false;
+	} else {
+		if (vmap->shared_tables) {
+			/* we cannot allow strict_mode because there are some
+			 * vrfs that share one or more tables.
+			 */
+			res = -EBUSY;
+			goto unlock;
+		}
+
+		/* no tables are shared among vrfs, so we can go back
+		 * to 1:1 association between a vrf with its table.
+		 */
+		*cur_mode = true;
+	}
+
+unlock:
+	vrf_map_unlock(vmap);
+
+	return res;
+}
+
+static int vrf_shared_table_handler(const struct ctl_table *table, int write,
+				    void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct net *net = (struct net *)table->extra1;
+	struct vrf_map *vmap = netns_vrf_map(net);
+	int proc_strict_mode = 0;
+	struct ctl_table tmp = {
+		.procname	= table->procname,
+		.data		= &proc_strict_mode,
+		.maxlen		= sizeof(int),
+		.mode		= table->mode,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE,
+	};
+	int ret;
+
+	if (!write)
+		proc_strict_mode = vrf_strict_mode(vmap);
+
+	ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
+
+	if (write && ret == 0)
+		ret = vrf_strict_mode_change(vmap, (bool)proc_strict_mode);
+
+	return ret;
+}
+
+static const struct ctl_table vrf_table[] = {
+	{
+		.procname	= "strict_mode",
+		.data		= NULL,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= vrf_shared_table_handler,
+		/* set by the vrf_netns_init */
+		.extra1		= NULL,
+	},
+};
+
+static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
+{
+	struct ctl_table *table;
+
+	table = kmemdup(vrf_table, sizeof(vrf_table), GFP_KERNEL);
+	if (!table)
+		return -ENOMEM;
+
+	/* init the extra1 parameter with the reference to current netns */
+	table[0].extra1 = net;
+
+	nn_vrf->ctl_hdr = register_net_sysctl_sz(net, "net/vrf", table,
+						 ARRAY_SIZE(vrf_table));
+	if (!nn_vrf->ctl_hdr) {
+		kfree(table);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void vrf_netns_exit_sysctl(struct net *net)
+{
+	struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
+	const struct ctl_table *table;
+
+	table = nn_vrf->ctl_hdr->ctl_table_arg;
+	unregister_net_sysctl_table(nn_vrf->ctl_hdr);
+	kfree(table);
+}
+#else
+static int vrf_netns_init_sysctl(struct net *net, struct netns_vrf *nn_vrf)
+{
+	return 0;
+}
+
+static void vrf_netns_exit_sysctl(struct net *net)
+{
+}
+#endif
+
+/* Initialize per network namespace state */
+static int __net_init vrf_netns_init(struct net *net)
+{
+	struct netns_vrf *nn_vrf = net_generic(net, vrf_net_id);
+
+	nn_vrf->add_fib_rules = true;
+	vrf_map_init(&nn_vrf->vmap);
+
+	return vrf_netns_init_sysctl(net, nn_vrf);
+}
+
+static void __net_exit vrf_netns_exit(struct net *net)
+{
+	vrf_netns_exit_sysctl(net);
+}
+
+static struct pernet_operations vrf_net_ops __net_initdata = {
+	.init = vrf_netns_init,
+	.exit = vrf_netns_exit,
+	.id   = &vrf_net_id,
+	.size = sizeof(struct netns_vrf),
+};
+
+static int __init vrf_init_module(void)
+{
+	int rc;
+
+	rc = register_netdevice_notifier(&vrf_notifier_block);
+	if (rc < 0)
+		return rc;
+
+	rc = register_pernet_subsys(&vrf_net_ops);
+	if (rc < 0)
+		goto error;
+
+	rc = l3mdev_table_lookup_register(L3MDEV_TYPE_VRF,
+					  vrf_ifindex_lookup_by_table_id);
+	if (rc < 0)
+		goto unreg_pernet;
+
+	rc = rtnl_link_register(&vrf_link_ops);
+	if (rc < 0)
+		goto table_lookup_unreg;
+
+	return 0;
+
+table_lookup_unreg:
+	l3mdev_table_lookup_unregister(L3MDEV_TYPE_VRF,
+				       vrf_ifindex_lookup_by_table_id);
+
+unreg_pernet:
+	unregister_pernet_subsys(&vrf_net_ops);
+
+error:
+	unregister_netdevice_notifier(&vrf_notifier_block);
+	return rc;
+}
+
+module_init(vrf_init_module);
+MODULE_AUTHOR("Shrijeet Mukherjee, David Ahern");
+MODULE_DESCRIPTION("Device driver to instantiate VRF domains");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_RTNL_LINK(DRV_NAME);
+MODULE_VERSION(DRV_VERSION);