net: Fix vti use case with oif in dst lookups

Steffen reported that the recent change to add oif to dst lookups breaks
the VTI use case. The problem is that with the oif set in the flow struct
the comparison to the nh_oif is triggered. Fix by splitting the
FLOWI_FLAG_VRFSRC into 2 flags -- one that triggers the vrf device cache
bypass (FLOWI_FLAG_VRFSRC) and another telling the lookup to not compare
nh oif (FLOWI_FLAG_SKIP_NH_OIF).

Fixes: 42a7b32b73d6 ("xfrm: Add oif to dst lookups")

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index e7094fb..488c6f5 100644 (file)
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -193,7 +193,8 @@ static netdev_tx_t vrf_process_v4_outbound(struct sk_buff *skb,
                .flowi4_oif = vrf_dev->ifindex,
                .flowi4_iif = LOOPBACK_IFINDEX,
                .flowi4_tos = RT_TOS(ip4h->tos),
-               .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_VRFSRC,
+               .flowi4_flags = FLOWI_FLAG_ANYSRC | FLOWI_FLAG_VRFSRC |
+                               FLOWI_FLAG_SKIP_NH_OIF,
                .daddr = ip4h->daddr,
        };
 

diff --git a/include/net/flow.h b/include/net/flow.h
index acd6a09..9b85db8 100644 (file)
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -35,6 +35,7 @@ struct flowi_common {
 #define FLOWI_FLAG_ANYSRC              0x01
 #define FLOWI_FLAG_KNOWN_NH            0x02
 #define FLOWI_FLAG_VRFSRC              0x04
+#define FLOWI_FLAG_SKIP_NH_OIF         0x08
        __u32   flowic_secid;
        struct flowi_tunnel flowic_tun_key;
 };

diff --git a/include/net/route.h b/include/net/route.h
index cc61cb9..f46af25 100644 (file)
--- a/include/net/route.h
+++ b/include/net/route.h
@@ -255,7 +255,7 @@ static inline void ip_route_connect_init(struct flowi4 *fl4, __be32 dst, __be32
                flow_flags |= FLOWI_FLAG_ANYSRC;
 
        if (netif_index_is_vrf(sock_net(sk), oif))
-               flow_flags |= FLOWI_FLAG_VRFSRC;
+               flow_flags |= FLOWI_FLAG_VRFSRC | FLOWI_FLAG_SKIP_NH_OIF;
 
        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 26d6ffb..6c2af79 100644 (file)
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1426,7 +1426,7 @@ found:
                            nh->nh_flags & RTNH_F_LINKDOWN &&
                            !(fib_flags & FIB_LOOKUP_IGNORE_LINKSTATE))
                                continue;
-                       if (!(flp->flowi4_flags & FLOWI_FLAG_VRFSRC)) {
+                       if (!(flp->flowi4_flags & FLOWI_FLAG_SKIP_NH_OIF)) {
                                if (flp->flowi4_oif &&
                                    flp->flowi4_oif != nh->nh_oif)
                                        continue;

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index c0a15e7..f7d1d5e 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1024,7 +1024,8 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
                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),
+                                          (flow_flags | FLOWI_FLAG_VRFSRC |
+                                           FLOWI_FLAG_SKIP_NH_OIF),
                                           faddr, saddr, dport,
                                           inet->inet_sport);
 

diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index bb919b2..c10a9ee 100644 (file)
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -33,6 +33,8 @@ static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4,
        if (saddr)
                fl4->saddr = saddr->a4;
 
+       fl4->flowi4_flags = FLOWI_FLAG_SKIP_NH_OIF;
+
        rt = __ip_route_output_key(net, fl4);
        if (!IS_ERR(rt))
                return &rt->dst;