Merge branch 'vrf-lite'

David Ahern says:

====================
VRF-lite - v6

In the context of internet scale routing a requirement that always comes
up is the need to partition the available routing tables into disjoint
routing planes. A specific use case is the multi-tenancy problem where
each tenant has their own unique routing tables and in the very least
need different default gateways.

This patch allows the ability to create virtual router domains (aka VRFs
(VRF-lite to be specific) in the linux packet forwarding stack. The main
observation is that through the use of rules and socket binding to interfaces,
all the facilities that we need are already present in the infrastructure. What
is missing is a handle that identifies a routing domain and can be used to
gather applicable rules/tables and uniqify neighbor selection. The scheme used
needs to preserves the notions of ECMP, and general routing principles.

This driver is a cross between functionality that the IPVLAN driver
and the Team drivers provide where a device is created and packets
into/out of the routing domain are shuttled through this device. The
device is then used as a handle to identify the applicable rules. The
VRF device is thus the layer3 equivalent of a vlan device.

The very important point to note is that this is only a Layer3 concept
so L2 tools (e.g., LLDP) do not need to be run in each VRF, processes can
run in unaware mode or select a VRF to be talking through. Also the
behavioral model is a generalized application of the familiar VRF-Lite
model with some performance paths that need optimization. (Specifically
the output route selector that Roopa, Robert, Thomas and EricB are
currently discussing on the MPLS thread)

High Level points
=================
1. Simple overlay driver (minimal changes to current stack)
   * uses the existing fib tables and fib rules infrastructure
2. Modelled closely after the ipvlan driver
3. Uses current API and infrastructure.
   * Applications can use SO_BINDTODEVICE or cmsg device indentifiers
     to pick VRF (ping, traceroute just work)
   * Standard IP Rules work, and since they are aggregated against the
     device, scale is manageable
4. Completely orthogonal to Namespaces and only provides separation in
   the routing plane (and ARP)

                                                 N2
           N1 (all configs here)          +---------------+
    +--------------+                      |               |
    |swp1 :10.0.1.1+----------------------+swp1 :10.0.1.2 |
    |              |                      |               |
    |swp2 :10.0.2.1+----------------------+swp2 :10.0.2.2 |
    |              |                      +---------------+
    | VRF 1        |
    | table 5      |
    |              |
    +---------------+
    |              |
    | VRF 2        |                             N3
    | table 6      |                      +---------------+
    |              |                      |               |
    |swp3 :10.0.2.1+----------------------+swp1 :10.0.2.2 |
    |              |                      |               |
    |swp4 :10.0.3.1+----------------------+swp2 :10.0.3.2 |
    +--------------+                      +---------------+

Given the topology above, the setup needed to get the basic VRF
functions working would be

Create the VRF devices and associate with a table
    ip link add vrf1 type vrf table 5
    ip link add vrf2 type vrf table 6

Install the lookup rules that map table to VRF domain
    ip rule add pref 200 oif vrf1 lookup 5
    ip rule add pref 200 iif vrf1 lookup 5
    ip rule add pref 200 oif vrf2 lookup 6
    ip rule add pref 200 iif vrf2 lookup 6

    ip link set vrf1 up
    ip link set vrf2 up

Enslave the routing member interfaces
    ip link set swp1 master vrf1
    ip link set swp2 master vrf1
    ip link set swp3 master vrf2
    ip link set swp4 master vrf2

Connected and local routes are automatically moved from main and local
tables to the VRF table.

ping using VRF0 is simply
    ping -I vrf0 10.0.1.2

Design Highlights
=================
If a device is enslaved to a VRF device (ie., associated with a VRF)
then:
1. Rx path
   The master device index is used as the iif for all lookups.

2. Tx path
   Similarly, for Tx the VRF device oif is used in the flow to direct
   lookups to the table associated with the VRF via its rule. From there
   the FLOWI_FLAG_VRFSRC flag is used to indicate that the oif should
   not be used for FIB table lookups.

3. Connected and local routes
   On link up for a device, connected and local routes are added to the
   table associated with the VRF device, rather than the local and main
   tables.

4. Socket lookups
   Sockets operating in the VRF must be bound to the VRF device. As such
   socket lookups compare the VRF device index to sk_bound_dev_if.

5. Neighbor entries
   Neighbor entries are not impacted by the VRF device. Entries are
   associated with a particular interface; the VRF association is indirect
   via the interface-to-VRF device enslavement.

Version 6
- addressed comments from DaveM

- added patch to properly set oif in ip_send_unicast_reply. Needs to be
  set to VRF device for proper FIB lookup

- added patch to handle IP fragments

Version 5
- dropped patch regarding socket lookups; no longer needed
  + removed vrf helpers no longer needed after this patch is dropped
- removed dev_open and close operations
  + no need to reset vrf data on an ifdown and creates problems if a
    slave is deleted while the vrf interface is down (Thanks, Nikolay)
- cleanups for sparse warnings
  + make C=2 is now clean for vrf driver

Version 4
- builds are clean with and without VRF device enabled (no, yes and module)
- tightened the driver implementation
  + device add/delete, slave add/remove, and module unload are all clean
- fixed RCU references
  + with RCU and lock debugging enabled changes are clean through the
    suite of tests
- TX path uses custom dst, so patch refactoring rtable allocation is
  dropped along with the patch adding rt_nexthop helper
- dropped the task patch that adds default bind to interface for sockets
  and the associated chvrf example command
  + the patches are a convenience for running unmodified code. They
    are not needed for the core functionality. Any application with
    support for SO_BINDTODEVICE works properly with this patch set.

Version 3
- addressed comments from first 2 RFCs with the exception of the name
  Nicolas: We will do the name conversion once we agree on what the
           correct name should be (vrf, mrf or something else)

-  packets flow through the VRF device in both directions allowing the
   following:
   - tcpdump -i vrf<n>
   - tc rules on vrf device
   - netfilter rules on vrf device

TO-DO
=====
1. IPv6

2. ipsec, xfrms
   - dst patch accepted into ipsec-next; will post VRF patch once merge happens

3. listen filter to allow 1 socket to work with multiple VRF devices
   - i.e., bind to VRF's a, b, c only or NOT VRFs e, f, g

Eric B:
  I have ipsec working with VRFs implemented using the VRF driver,
  including the worst case scenario of complete duplication in the
  networking config.

Thanks to Nikolay for his many, many code reviews whipping the device
driver into shape, and bug-Fixes and ideas from Hannes, Roopa Prabhu,
Jon Toppins, Jamal.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

10 files changed, 162 insertions, 44 deletions

diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index cc4e498a0ccf..c8b855882fa5 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -119,6 +119,7 @@
 #ifdef CONFIG_IP_MROUTE
 #include <linux/mroute.h>
 #endif
+#include <net/vrf.h>
 
 
 /* The inetsw table contains everything that inet_create needs to
@@ -427,6 +428,7 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	struct net *net = sock_net(sk);
 	unsigned short snum;
 	int chk_addr_ret;
+	int tb_id = RT_TABLE_LOCAL;
 	int err;
 
 	/* If the socket has its own bind function then use it. (RAW) */
@@ -448,7 +450,16 @@ int inet_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 			goto out;
 	}
 
-	chk_addr_ret = inet_addr_type(net, addr->sin_addr.s_addr);
+	if (sk->sk_bound_dev_if) {
+		struct net_device *dev;
+
+		rcu_read_lock();
+		dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
+		if (dev)
+			tb_id = vrf_dev_table_rcu(dev) ? : tb_id;
+		rcu_read_unlock();
+	}
+	chk_addr_ret = inet_addr_type_table(net, addr->sin_addr.s_addr, tb_id);
 
 	/* Not specified by any standard per-se, however it breaks too
 	 * many applications when removed.  It is unfortunate since
diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c
index 34a308573f4b..30409b75e925 100644
--- a/net/ipv4/arp.c
+++ b/net/ipv4/arp.c
@@ -233,7 +233,7 @@ static int arp_constructor(struct neighbour *neigh)
 		return -EINVAL;
 	}
 
-	neigh->type = inet_addr_type(dev_net(dev), addr);
+	neigh->type = inet_addr_type_dev_table(dev_net(dev), dev, addr);
 
 	parms = in_dev->arp_parms;
 	__neigh_parms_put(neigh->parms);
@@ -343,7 +343,7 @@ static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
 	switch (IN_DEV_ARP_ANNOUNCE(in_dev)) {
 	default:
 	case 0:		/* By default announce any local IP */
-		if (skb && inet_addr_type(dev_net(dev),
+		if (skb && inet_addr_type_dev_table(dev_net(dev), dev,
 					  ip_hdr(skb)->saddr) == RTN_LOCAL)
 			saddr = ip_hdr(skb)->saddr;
 		break;
@@ -351,7 +351,8 @@ static void arp_solicit(struct neighbour *neigh, struct sk_buff *skb)
 		if (!skb)
 			break;
 		saddr = ip_hdr(skb)->saddr;
-		if (inet_addr_type(dev_net(dev), saddr) == RTN_LOCAL) {
+		if (inet_addr_type_dev_table(dev_net(dev), dev,
+					     saddr) == RTN_LOCAL) {
 			/* saddr should be known to target */
 			if (inet_addr_onlink(in_dev, target, saddr))
 				break;
@@ -751,7 +752,7 @@ static int arp_process(struct sock *sk, struct sk_buff *skb)
 	/* Special case: IPv4 duplicate address detection packet (RFC2131) */
 	if (sip == 0) {
 		if (arp->ar_op == htons(ARPOP_REQUEST) &&
-		    inet_addr_type(net, tip) == RTN_LOCAL &&
+		    inet_addr_type_dev_table(net, dev, tip) == RTN_LOCAL &&
 		    !arp_ignore(in_dev, sip, tip))
 			arp_send(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha,
 				 dev->dev_addr, sha);
@@ -811,16 +812,18 @@ static int arp_process(struct sock *sk, struct sk_buff *skb)
 	n = __neigh_lookup(&arp_tbl, &sip, dev, 0);
 
 	if (IN_DEV_ARP_ACCEPT(in_dev)) {
+		unsigned int addr_type = inet_addr_type_dev_table(net, dev, sip);
+
 		/* Unsolicited ARP is not accepted by default.
 		   It is possible, that this option should be enabled for some
 		   devices (strip is candidate)
 		 */
 		is_garp = arp->ar_op == htons(ARPOP_REQUEST) && tip == sip &&
-			  inet_addr_type(net, sip) == RTN_UNICAST;
+			  addr_type == RTN_UNICAST;
 
 		if (!n &&
 		    ((arp->ar_op == htons(ARPOP_REPLY)  &&
-		      inet_addr_type(net, sip) == RTN_UNICAST) || is_garp))
+				addr_type == RTN_UNICAST) || is_garp))
 			n = __neigh_lookup(&arp_tbl, &sip, dev, 1);
 	}
 
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 6b98de0d7949..7fa277176c33 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -45,6 +45,7 @@
 #include <net/ip_fib.h>
 #include <net/rtnetlink.h>
 #include <net/xfrm.h>
+#include <net/vrf.h>
 
 #ifndef CONFIG_IP_MULTIPLE_TABLES
 
@@ -211,12 +212,12 @@ void fib_flush_external(struct net *net)
  */
 static inline unsigned int __inet_dev_addr_type(struct net *net,
 						const struct net_device *dev,
-						__be32 addr)
+						__be32 addr, int tb_id)
 {
 	struct flowi4		fl4 = { .daddr = addr };
 	struct fib_result	res;
 	unsigned int ret = RTN_BROADCAST;
-	struct fib_table *local_table;
+	struct fib_table *table;
 
 	if (ipv4_is_zeronet(addr) || ipv4_is_lbcast(addr))
 		return RTN_BROADCAST;
@@ -225,10 +226,10 @@ static inline unsigned int __inet_dev_addr_type(struct net *net,
 
 	rcu_read_lock();
 
-	local_table = fib_get_table(net, RT_TABLE_LOCAL);
-	if (local_table) {
+	table = fib_get_table(net, tb_id);
+	if (table) {
 		ret = RTN_UNICAST;
-		if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
+		if (!fib_table_lookup(table, &fl4, &res, FIB_LOOKUP_NOREF)) {
 			if (!dev || dev == res.fi->fib_dev)
 				ret = res.type;
 		}
@@ -238,19 +239,40 @@ static inline unsigned int __inet_dev_addr_type(struct net *net,
 	return ret;
 }
 
+unsigned int inet_addr_type_table(struct net *net, __be32 addr, int tb_id)
+{
+	return __inet_dev_addr_type(net, NULL, addr, tb_id);
+}
+EXPORT_SYMBOL(inet_addr_type_table);
+
 unsigned int inet_addr_type(struct net *net, __be32 addr)
 {
-	return __inet_dev_addr_type(net, NULL, addr);
+	return __inet_dev_addr_type(net, NULL, addr, RT_TABLE_LOCAL);
 }
 EXPORT_SYMBOL(inet_addr_type);
 
 unsigned int inet_dev_addr_type(struct net *net, const struct net_device *dev,
 				__be32 addr)
 {
-	return __inet_dev_addr_type(net, dev, addr);
+	int rt_table = vrf_dev_table(dev) ? : RT_TABLE_LOCAL;
+
+	return __inet_dev_addr_type(net, dev, addr, rt_table);
 }
 EXPORT_SYMBOL(inet_dev_addr_type);
 
+/* inet_addr_type with dev == NULL but using the table from a dev
+ * if one is associated
+ */
+unsigned int inet_addr_type_dev_table(struct net *net,
+				      const struct net_device *dev,
+				      __be32 addr)
+{
+	int rt_table = vrf_dev_table(dev) ? : RT_TABLE_LOCAL;
+
+	return __inet_dev_addr_type(net, NULL, addr, rt_table);
+}
+EXPORT_SYMBOL(inet_addr_type_dev_table);
+
 __be32 fib_compute_spec_dst(struct sk_buff *skb)
 {
 	struct net_device *dev = skb->dev;
@@ -309,7 +331,9 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 	bool dev_match;
 
 	fl4.flowi4_oif = 0;
-	fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
+	fl4.flowi4_iif = vrf_master_ifindex_rcu(dev);
+	if (!fl4.flowi4_iif)
+		fl4.flowi4_iif = oif ? : LOOPBACK_IFINDEX;
 	fl4.daddr = src;
 	fl4.saddr = dst;
 	fl4.flowi4_tos = tos;
@@ -339,6 +363,9 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 		if (nh->nh_dev == dev) {
 			dev_match = true;
 			break;
+		} else if (vrf_master_ifindex_rcu(nh->nh_dev) == dev->ifindex) {
+			dev_match = true;
+			break;
 		}
 	}
 #else
@@ -496,9 +523,12 @@ static int rtentry_to_fib_config(struct net *net, int cmd, struct rtentry *rt,
 
 	addr = sk_extract_addr(&rt->rt_gateway);
 	if (rt->rt_gateway.sa_family == AF_INET && addr) {
+		unsigned int addr_type;
+
 		cfg->fc_gw = addr;
+		addr_type = inet_addr_type_table(net, addr, cfg->fc_table);
 		if (rt->rt_flags & RTF_GATEWAY &&
-		    inet_addr_type(net, addr) == RTN_UNICAST)
+		    addr_type == RTN_UNICAST)
 			cfg->fc_scope = RT_SCOPE_UNIVERSE;
 	}
 
@@ -770,6 +800,7 @@ out:
 static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifaddr *ifa)
 {
 	struct net *net = dev_net(ifa->ifa_dev->dev);
+	int tb_id = vrf_dev_table_rtnl(ifa->ifa_dev->dev);
 	struct fib_table *tb;
 	struct fib_config cfg = {
 		.fc_protocol = RTPROT_KERNEL,
@@ -784,11 +815,10 @@ static void fib_magic(int cmd, int type, __be32 dst, int dst_len, struct in_ifad
 		},
 	};
 
-	if (type == RTN_UNICAST)
-		tb = fib_new_table(net, RT_TABLE_MAIN);
-	else
-		tb = fib_new_table(net, RT_TABLE_LOCAL);
+	if (!tb_id)
+		tb_id = (type == RTN_UNICAST) ? RT_TABLE_MAIN : RT_TABLE_LOCAL;
 
+	tb = fib_new_table(net, tb_id);
 	if (!tb)
 		return;
 
@@ -970,11 +1000,14 @@ void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim)
 			fib_magic(RTM_DELROUTE, RTN_BROADCAST, any, 32, prim);
 	}
 	if (!(ok & LOCAL_OK)) {
+		unsigned int addr_type;
+
 		fib_magic(RTM_DELROUTE, RTN_LOCAL, ifa->ifa_local, 32, prim);
 
 		/* Check, that this local address finally disappeared. */
-		if (gone &&
-		    inet_addr_type(dev_net(dev), ifa->ifa_local) != RTN_LOCAL) {
+		addr_type = inet_addr_type_dev_table(dev_net(dev), dev,
+						     ifa->ifa_local);
+		if (gone && addr_type != RTN_LOCAL) {
 			/* And the last, but not the least thing.
 			 * We must flush stray FIB entries.
 			 *
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 558e196bae0f..b7f1d20a9615 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -670,16 +670,18 @@ static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi,
 		struct fib_result res;
 
 		if (nh->nh_flags & RTNH_F_ONLINK) {
+			unsigned int addr_type;
 
 			if (cfg->fc_scope >= RT_SCOPE_LINK)
 				return -EINVAL;
-			if (inet_addr_type(net, nh->nh_gw) != RTN_UNICAST)
-				return -EINVAL;
 			dev = __dev_get_by_index(net, nh->nh_oif);
 			if (!dev)
 				return -ENODEV;
 			if (!(dev->flags & IFF_UP))
 				return -ENETDOWN;
+			addr_type = inet_addr_type_dev_table(net, dev, nh->nh_gw);
+			if (addr_type != RTN_UNICAST)
+				return -EINVAL;
 			if (!netif_carrier_ok(dev))
 				nh->nh_flags |= RTNH_F_LINKDOWN;
 			nh->nh_dev = dev;
@@ -689,6 +691,7 @@ static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi,
 		}
 		rcu_read_lock();
 		{
+			struct fib_table *tbl = NULL;
 			struct flowi4 fl4 = {
 				.daddr = nh->nh_gw,
 				.flowi4_scope = cfg->fc_scope + 1,
@@ -699,8 +702,16 @@ static int fib_check_nh(struct fib_config *cfg, struct fib_info *fi,
 			/* It is not necessary, but requires a bit of thinking */
 			if (fl4.flowi4_scope < RT_SCOPE_LINK)
 				fl4.flowi4_scope = RT_SCOPE_LINK;
-			err = fib_lookup(net, &fl4, &res,
-					 FIB_LOOKUP_IGNORE_LINKSTATE);
+
+			if (cfg->fc_table)
+				tbl = fib_get_table(net, cfg->fc_table);
+
+			if (tbl)
+				err = fib_table_lookup(tbl, &fl4, &res,
+						   FIB_LOOKUP_IGNORE_LINKSTATE);
+			else
+				err = fib_lookup(net, &fl4, &res,
+						 FIB_LOOKUP_IGNORE_LINKSTATE);
 			if (err) {
 				rcu_read_unlock();
 				return err;
@@ -836,6 +847,23 @@ __be32 fib_info_update_nh_saddr(struct net *net, struct fib_nh *nh)
 	return nh->nh_saddr;
 }
 
+static bool fib_valid_prefsrc(struct fib_config *cfg, __be32 fib_prefsrc)
+{
+	if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
+	    fib_prefsrc != cfg->fc_dst) {
+		int tb_id = cfg->fc_table;
+
+		if (tb_id == RT_TABLE_MAIN)
+			tb_id = RT_TABLE_LOCAL;
+
+		if (inet_addr_type_table(cfg->fc_nlinfo.nl_net,
+					 fib_prefsrc, tb_id) != RTN_LOCAL) {
+			return false;
+		}
+	}
+	return true;
+}
+
 struct fib_info *fib_create_info(struct fib_config *cfg)
 {
 	int err;
@@ -1031,12 +1059,8 @@ struct fib_info *fib_create_info(struct fib_config *cfg)
 			fi->fib_flags |= RTNH_F_LINKDOWN;
 	}
 
-	if (fi->fib_prefsrc) {
-		if (cfg->fc_type != RTN_LOCAL || !cfg->fc_dst ||
-		    fi->fib_prefsrc != cfg->fc_dst)
-			if (inet_addr_type(net, fi->fib_prefsrc) != RTN_LOCAL)
-				goto err_inval;
-	}
+	if (fi->fib_prefsrc && !fib_valid_prefsrc(cfg, fi->fib_prefsrc))
+		goto err_inval;
 
 	change_nexthops(fi) {
 		fib_info_update_nh_saddr(net, nexthop_nh);
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 37c4bb89a708..1243c79cb5b0 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1423,8 +1423,11 @@ found:
 			    nh->nh_flags & RTNH_F_LINKDOWN &&
 			    !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
 				continue;
-			if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
-				continue;
+			if (!(flp->flowi4_flags & FLOWI_FLAG_VRFSRC)) {
+				if (flp->flowi4_oif &&
+				    flp->flowi4_oif != nh->nh_oif)
+					continue;
+			}
 
 			if (!(fib_flags & FIB_LOOKUP_NOREF))
 				atomic_inc(&fi->fib_clntref);
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index c0556f1e4bf0..c6f1ce149ffb 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -96,6 +96,7 @@
 #include <net/xfrm.h>
 #include <net/inet_common.h>
 #include <net/ip_fib.h>
+#include <net/vrf.h>
 
 /*
  *	Build xmit assembly blocks
@@ -425,6 +426,7 @@ static void icmp_reply(struct icmp_bxm *icmp_param, struct sk_buff *skb)
 	fl4.flowi4_mark = mark;
 	fl4.flowi4_tos = RT_TOS(ip_hdr(skb)->tos);
 	fl4.flowi4_proto = IPPROTO_ICMP;
+	fl4.flowi4_oif = vrf_master_ifindex_rcu(skb->dev) ? : skb->dev->ifindex;
 	security_skb_classify_flow(skb, flowi4_to_flowi(&fl4));
 	rt = ip_route_output_key(net, &fl4);
 	if (IS_ERR(rt))
@@ -458,6 +460,8 @@ static struct rtable *icmp_route_lookup(struct net *net,
 	fl4->flowi4_proto = IPPROTO_ICMP;
 	fl4->fl4_icmp_type = type;
 	fl4->fl4_icmp_code = code;
+	fl4->flowi4_oif = vrf_master_ifindex_rcu(skb_in->dev) ? : skb_in->dev->ifindex;
+
 	security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4));
 	rt = __ip_route_output_key(net, fl4);
 	if (IS_ERR(rt))
@@ -480,7 +484,8 @@ static struct rtable *icmp_route_lookup(struct net *net,
 	if (err)
 		goto relookup_failed;
 
-	if (inet_addr_type(net, fl4_dec.saddr) == RTN_LOCAL) {
+	if (inet_addr_type_dev_table(net, skb_in->dev,
+				     fl4_dec.saddr) == RTN_LOCAL) {
 		rt2 = __ip_route_output_key(net, &fl4_dec);
 		if (IS_ERR(rt2))
 			err = PTR_ERR(rt2);
@@ -829,7 +834,7 @@ static bool icmp_unreach(struct sk_buff *skb)
 	 */
 
 	if (!net->ipv4.sysctl_icmp_ignore_bogus_error_responses &&
-	    inet_addr_type(net, iph->daddr) == RTN_BROADCAST) {
+	    inet_addr_type_dev_table(net, skb->dev, iph->daddr) == RTN_BROADCAST) {
 		net_warn_ratelimited("%pI4 sent an invalid ICMP type %u, code %u error to a broadcast: %pI4 on %s\n",
 				     &ip_hdr(skb)->saddr,
 				     icmph->type, icmph->code,
diff --git a/net/ipv4/ip_fragment.c b/net/ipv4/ip_fragment.c
index d96722ae8979..15762e758861 100644
--- a/net/ipv4/ip_fragment.c
+++ b/net/ipv4/ip_fragment.c
@@ -48,6 +48,7 @@
 #include <linux/inet.h>
 #include <linux/netfilter_ipv4.h>
 #include <net/inet_ecn.h>
+#include <net/vrf.h>
 
 /* NOTE. Logic of IP defragmentation is parallel to corresponding IPv6
  * code now. If you change something here, _PLEASE_ update ipv6/reassembly.c
@@ -77,6 +78,7 @@ struct ipq {
 	u8		ecn; /* RFC3168 support */
 	u16		max_df_size; /* largest frag with DF set seen */
 	int             iif;
+	int             vif;   /* VRF device index */
 	unsigned int    rid;
 	struct inet_peer *peer;
 };
@@ -99,6 +101,7 @@ static int ip_frag_reasm(struct ipq *qp, struct sk_buff *prev,
 struct ip4_create_arg {
 	struct iphdr *iph;
 	u32 user;
+	int vif;
 };
 
 static unsigned int ipqhashfn(__be16 id, __be32 saddr, __be32 daddr, u8 prot)
@@ -127,7 +130,8 @@ static bool ip4_frag_match(const struct inet_frag_queue *q, const void *a)
 		qp->saddr == arg->iph->saddr &&
 		qp->daddr == arg->iph->daddr &&
 		qp->protocol == arg->iph->protocol &&
-		qp->user == arg->user;
+		qp->user == arg->user &&
+		qp->vif == arg->vif;
 }
 
 static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
@@ -144,6 +148,7 @@ static void ip4_frag_init(struct inet_frag_queue *q, const void *a)
 	qp->ecn = ip4_frag_ecn(arg->iph->tos);
 	qp->saddr = arg->iph->saddr;
 	qp->daddr = arg->iph->daddr;
+	qp->vif = arg->vif;
 	qp->user = arg->user;
 	qp->peer = sysctl_ipfrag_max_dist ?
 		inet_getpeer_v4(net->ipv4.peers, arg->iph->saddr, 1) : NULL;
@@ -244,7 +249,8 @@ out:
 /* Find the correct entry in the "incomplete datagrams" queue for
  * this IP datagram, and create new one, if nothing is found.
  */
-static struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user)
+static struct ipq *ip_find(struct net *net, struct iphdr *iph,
+			   u32 user, int vif)
 {
 	struct inet_frag_queue *q;
 	struct ip4_create_arg arg;
@@ -252,6 +258,7 @@ static struct ipq *ip_find(struct net *net, struct iphdr *iph, u32 user)
 
 	arg.iph = iph;
 	arg.user = user;
+	arg.vif = vif;
 
 	hash = ipqhashfn(iph->id, iph->saddr, iph->daddr, iph->protocol);
 
@@ -648,14 +655,15 @@ out_fail:
 /* Process an incoming IP datagram fragment. */
 int ip_defrag(struct sk_buff *skb, u32 user)
 {
+	struct net_device *dev = skb->dev ? : skb_dst(skb)->dev;
+	int vif = vrf_master_ifindex_rcu(dev);
+	struct net *net = dev_net(dev);
 	struct ipq *qp;
-	struct net *net;
 
-	net = skb->dev ? dev_net(skb->dev) : dev_net(skb_dst(skb)->dev);
 	IP_INC_STATS_BH(net, IPSTATS_MIB_REASMREQDS);
 
 	/* Lookup (or create) queue header */
-	qp = ip_find(net, ip_hdr(skb), user);
+	qp = ip_find(net, ip_hdr(skb), user, vif);
 	if (qp) {
 		int ret;
 
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 6bf89a6312bc..0138fada0951 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1542,6 +1542,7 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 	struct net *net = sock_net(sk);
 	struct sk_buff *nskb;
 	int err;
+	int oif;
 
 	if (__ip_options_echo(&replyopts.opt.opt, skb, sopt))
 		return;
@@ -1559,7 +1560,11 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb,
 			daddr = replyopts.opt.opt.faddr;
 	}
 
-	flowi4_init_output(&fl4, arg->bound_dev_if,
+	oif = arg->bound_dev_if;
+	if (!oif && netif_index_is_vrf(net, skb->skb_iif))
+		oif = skb->skb_iif;
+
+	flowi4_init_output(&fl4, oif,
 			   IP4_REPLY_MARK(net, skb->mark),
 			   RT_TOS(arg->tos),
 			   RT_SCOPE_UNIVERSE, ip_hdr(skb)->protocol,
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 18fd7c9095c7..2c89d294b669 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -112,6 +112,7 @@
 #endif
 #include <net/secure_seq.h>
 #include <net/ip_tunnels.h>
+#include <net/vrf.h>
 
 #define RT_FL_TOS(oldflp4) \
 	((oldflp4)->flowi4_tos & (IPTOS_RT_MASK | RTO_ONLINK))
@@ -1726,7 +1727,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr,
 	 *	Now we are ready to route packet.
 	 */
 	fl4.flowi4_oif = 0;
-	fl4.flowi4_iif = dev->ifindex;
+	fl4.flowi4_iif = vrf_master_ifindex_rcu(dev) ? : dev->ifindex;
 	fl4.flowi4_mark = skb->mark;
 	fl4.flowi4_tos = tos;
 	fl4.flowi4_scope = RT_SCOPE_UNIVERSE;
@@ -2130,6 +2131,11 @@ struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *fl4)
 				fl4->saddr = inet_select_addr(dev_out, 0,
 							      RT_SCOPE_HOST);
 		}
+		if (netif_is_vrf(dev_out) &&
+		    !(fl4->flowi4_flags & FLOWI_FLAG_VRFSRC)) {
+			rth = vrf_dev_get_rth(dev_out);
+			goto out;
+		}
 	}
 
 	if (!fl4->daddr) {
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 1b8c5ba7d5f7..c0a15e7f359f 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1013,11 +1013,31 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
 	if (!rt) {
 		struct net *net = sock_net(sk);
+		__u8 flow_flags = inet_sk_flowi_flags(sk);
 
 		fl4 = &fl4_stack;
+
+		/* unconnected socket. If output device is enslaved to a VRF
+		 * device lookup source address from VRF table. This mimics
+		 * behavior of ip_route_connect{_init}.
+		 */
+		if (netif_index_is_vrf(net, ipc.oif)) {
+			flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
+					   RT_SCOPE_UNIVERSE, sk->sk_protocol,
+					   (flow_flags | FLOWI_FLAG_VRFSRC),
+					   faddr, saddr, dport,
+					   inet->inet_sport);
+
+			rt = ip_route_output_flow(net, fl4, sk);
+			if (!IS_ERR(rt)) {
+				saddr = fl4->saddr;
+				ip_rt_put(rt);
+			}
+		}
+
 		flowi4_init_output(fl4, ipc.oif, sk->sk_mark, tos,
 				   RT_SCOPE_UNIVERSE, sk->sk_protocol,
-				   inet_sk_flowi_flags(sk),
+				   flow_flags,
 				   faddr, saddr, dport, inet->inet_sport);
 
 		security_sk_classify_flow(sk, flowi4_to_flowi(fl4));