ipv6: Fix PMTU updates for UDP/raw sockets in presence of VRF

Preethi reported that PMTU discovery for UDP/raw applications is not working in the presence of VRF when the socket is not bound to a device. The problem is that ip6_sk_update_pmtu does not consider the L3 domain of the skb device if the socket is not bound. Update the function to set oif to the L3 master device if relevant. Fixes: ca25449 ("net: Add VRF support to IPv6 stack") Reported-by: Preethi Ramachandra <[email protected]> Signed-off-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
broSysX64 · Nov 19, 2018 · 7ddacfa · 7ddacfa
1 parent 1c1274a
commit 7ddacfa
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
@@ -2359,10 +2359,13 @@ EXPORT_SYMBOL_GPL(ip6_update_pmtu);
 
 void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
 {
+	int oif = sk->sk_bound_dev_if;
 	struct dst_entry *dst;
 
-	ip6_update_pmtu(skb, sock_net(sk), mtu,
-			sk->sk_bound_dev_if, sk->sk_mark, sk->sk_uid);
+	if (!oif && skb->dev)
+		oif = l3mdev_master_ifindex(skb->dev);
+
+	ip6_update_pmtu(skb, sock_net(sk), mtu, oif, sk->sk_mark, sk->sk_uid);
 
 	dst = __sk_dst_get(sk);
 	if (!dst || !dst->obsolete ||