[PATCH net-next 03/11] net: Use VRF device index for lookups on TX

[David Ahern <dsa@cumulusnetworks.com>]

As with ingress use the index of VRF master device for route lookups on
egress. However, the oif should only be used to direct the lookups to a
specific table. Routes in the table are not based on the VRF device but
rather interfaces that are part of the VRF so do not consider the oif for
lookups within the table. The FLOWI_FLAG_VRFSRC is used to control this
latter part.

Signed-off-by: Shrijeet Mukherjee <shm@cumulusnetworks.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
---
 include/net/flow.h  | 1 +
 include/net/route.h | 3 +++
 net/ipv4/fib_trie.c | 7 +++++--
 net/ipv4/icmp.c     | 4 ++++
 net/ipv4/route.c    | 5 +++++
 5 files changed, 18 insertions(+), 2 deletions(-)

diff --git a/include/net/flow.h b/include/net/flow.h
index 3098ae33a178..f305588fc162 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -33,6 +33,7 @@ struct flowi_common {
 	__u8	flowic_flags;
 #define FLOWI_FLAG_ANYSRC		0x01
 #define FLOWI_FLAG_KNOWN_NH		0x02
+#define FLOWI_FLAG_VRFSRC		0x04
 	__u32	flowic_secid;
 	struct flowi_tunnel flowic_tun_key;
 };
diff --git a/include/net/route.h b/include/net/route.h
index 2d45f419477f..94189d4bd899 100644
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -251,6 +251,9 @@ static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32
 	if (inet_sk(sk)->transparent)
 		flow_flags |= FLOWI_FLAG_ANYSRC;
 
+	if (netif_index_is_vrf(sock_net(sk), oif))
+		flow_flags |= FLOWI_FLAG_VRFSRC;
+
 	flowi4_init_output(fl4, oif, sk->sk_mark, tos, RT_SCOPE_UNIVERSE,
 			   protocol, flow_flags, dst, src, dport, sport);
 }
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 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 			    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..1164fc4ce3bc 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))
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index c26ff1f7067d..2c89d294b669 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2131,6 +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) {
-- 
2.3.2 (Apple Git-55)