Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2072 insertions, 0 deletions

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
new file mode 100644
index 000000000..208df4d41
--- /dev/null
+++ b/drivers/net/vrf.c
@@ -0,0 +1,2072 @@
+// 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/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/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 __rcu	*rth;
+	struct rt6_info	__rcu	*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;
+};
+
+struct pcpu_dstats {
+	u64			tx_pkts;
+	u64			tx_bytes;
+	u64			tx_drps;
+	u64			rx_pkts;
+	u64			rx_bytes;
+	u64			rx_drps;
+	struct u64_stats_sync	syncp;
+};
+
+static void vrf_rx_stats(struct net_device *dev, int len)
+{
+	struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
+
+	u64_stats_update_begin(&dstats->syncp);
+	dstats->rx_pkts++;
+	dstats->rx_bytes += len;
+	u64_stats_update_end(&dstats->syncp);
+}
+
+static void vrf_tx_error(struct net_device *vrf_dev, struct sk_buff *skb)
+{
+	vrf_dev->stats.tx_errors++;
+	kfree_skb(skb);
+}
+
+static void vrf_get_stats64(struct net_device *dev,
+			    struct rtnl_link_stats64 *stats)
+{
+	int i;
+
+	for_each_possible_cpu(i) {
+		const struct pcpu_dstats *dstats;
+		u64 tbytes, tpkts, tdrops, rbytes, rpkts;
+		unsigned int start;
+
+		dstats = per_cpu_ptr(dev->dstats, i);
+		do {
+			start = u64_stats_fetch_begin_irq(&dstats->syncp);
+			tbytes = dstats->tx_bytes;
+			tpkts = dstats->tx_pkts;
+			tdrops = dstats->tx_drps;
+			rbytes = dstats->rx_bytes;
+			rpkts = dstats->rx_pkts;
+		} while (u64_stats_fetch_retry_irq(&dstats->syncp, start));
+		stats->tx_bytes += tbytes;
+		stats->tx_packets += tpkts;
+		stats->tx_dropped += tdrops;
+		stats->rx_bytes += rbytes;
+		stats->rx_packets += rpkts;
+	}
+}
+
+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(sizeof(*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;
+	struct Qdisc *qdisc;
+
+	if (dev->num_tx_queues > 1)
+		return false;
+
+	txq = netdev_get_tx_queue(dev, 0);
+	qdisc = rcu_access_pointer(txq->qdisc);
+
+	return !qdisc->enqueue;
+}
+
+/* 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)
+{
+	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))
+		vrf_rx_stats(dev, len);
+	else
+		this_cpu_inc(dev->dstats->rx_drps);
+
+	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_tos = RT_TOS(ip4h->tos);
+	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)
+{
+	int len = skb->len;
+	netdev_tx_t ret = is_ip_tx_frame(skb, dev);
+
+	if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
+		struct pcpu_dstats *dstats = this_cpu_ptr(dev->dstats);
+
+		u64_stats_update_begin(&dstats->syncp);
+		dstats->tx_pkts++;
+		dstats->tx_bytes += len;
+		u64_stats_update_end(&dstats->syncp);
+	} else {
+		this_cpu_inc(dev->dstats->tx_drps);
+	}
+
+	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((struct 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 dst_entry *dst = NULL;
+	struct rt6_info *rt6;
+
+	rcu_read_lock();
+
+	rt6 = rcu_dereference(vrf->rt6);
+	if (likely(rt6)) {
+		dst = &rt6->dst;
+		dst_hold(dst);
+	}
+
+	rcu_read_unlock();
+
+	if (unlikely(!dst)) {
+		vrf_tx_error(vrf_dev, skb);
+		return NULL;
+	}
+
+	skb_dst_drop(skb);
+	skb_dst_set(skb, 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 = rtnl_dereference(vrf->rt6);
+	struct net *net = dev_net(dev);
+	struct dst_entry *dst;
+
+	RCU_INIT_POINTER(vrf->rt6, NULL);
+	synchronize_rcu();
+
+	/* move dev in dst's to loopback so this VRF device can be deleted
+	 * - based on dst_ifdown
+	 */
+	if (rt6) {
+		dst = &rt6->dst;
+		netdev_ref_replace(dst->dev, net->loopback_dev,
+				   &dst->dev_tracker, GFP_KERNEL);
+		dst->dev = net->loopback_dev;
+		dst_release(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;
+
+	rcu_assign_pointer(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 = (struct 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 dst_entry *dst = NULL;
+	struct rtable *rth;
+
+	rcu_read_lock();
+
+	rth = rcu_dereference(vrf->rth);
+	if (likely(rth)) {
+		dst = &rth->dst;
+		dst_hold(dst);
+	}
+
+	rcu_read_unlock();
+
+	if (unlikely(!dst)) {
+		vrf_tx_error(vrf_dev, skb);
+		return NULL;
+	}
+
+	skb_dst_drop(skb);
+	skb_dst_set(skb, 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 = rtnl_dereference(vrf->rth);
+	struct net *net = dev_net(dev);
+	struct dst_entry *dst;
+
+	RCU_INIT_POINTER(vrf->rth, NULL);
+	synchronize_rcu();
+
+	/* move dev in dst's to loopback so this VRF device can be deleted
+	 * - based on dst_ifdown
+	 */
+	if (rth) {
+		dst = &rth->dst;
+		netdev_ref_replace(dst->dev, net->loopback_dev,
+				   &dst->dev_tracker, GFP_KERNEL);
+		dst->dev = net->loopback_dev;
+		dst_release(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;
+
+	rcu_assign_pointer(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;
+	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)
+{
+	netdev_upper_dev_unlink(port_dev, dev);
+	port_dev->priv_flags &= ~IFF_L3MDEV_SLAVE;
+
+	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);
+}
+
+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);
+
+	free_percpu(dev->dstats);
+	dev->dstats = NULL;
+}
+
+static int vrf_dev_init(struct net_device *dev)
+{
+	struct net_vrf *vrf = netdev_priv(dev);
+
+	dev->dstats = netdev_alloc_pcpu_stats(struct pcpu_dstats);
+	if (!dev->dstats)
+		goto out_nomem;
+
+	/* create the default dst which points back to us */
+	if (vrf_rtable_create(dev) != 0)
+		goto out_stats;
+
+	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_stats:
+	free_percpu(dev->dstats);
+	dev->dstats = NULL;
+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_get_stats64	= vrf_get_stats64,
+	.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;
+
+	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;
+
+		vrf_rx_stats(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;
+	}
+
+	vrf_rx_stats(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);
+
+	/* fib_nl_{new,del}rule handling looks for net from skb->sk */
+	skb->sk = dev_net(dev)->rtnl;
+	if (add_it) {
+		err = fib_nl_newrule(skb, nlh, NULL);
+		if (err == -EEXIST)
+			err = 0;
+	} else {
+		err = fib_nl_delrule(skb, nlh, NULL);
+		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->features |= NETIF_F_LLTX;
+
+	/* don't allow vrf devices to change network namespaces. */
+	dev->features |= NETIF_F_NETNS_LOCAL;
+
+	/* 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;
+}
+
+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)
+		vrf_del_slave(dev, port_dev);
+
+	vrf_map_unregister_dev(dev);
+
+	unregister_netdevice_queue(dev, head);
+}
+
+static int vrf_newlink(struct net *src_net, struct net_device *dev,
+		       struct nlattr *tb[], struct nlattr *data[],
+		       struct netlink_ext_ack *extack)
+{
+	struct net_vrf *vrf = netdev_priv(dev);
+	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);
+		vrf_del_slave(vrf_dev, dev);
+	}
+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(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(net, "net/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);
+	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;
+
+	register_netdevice_notifier(&vrf_notifier_block);
+
+	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);