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

PATCH In review David Ahern 2 participants 2 messages Nov 19, 2018

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Networking Network drivers IPv4/IPv6
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David Ahern

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#0 lore raw

PATCH 1/1 ipv6: Fix PMTU updates for UDP/raw sockets in presence of VRF

From: David Ahern <[email protected]>

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 ca254490c8df ("net: Add VRF support to IPv6 stack")
Reported-by Preethi Ramachandra <[email protected]>
Signed-off-by David Ahern <[email protected]>
---
 net/ipv6/route.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)
net/ipv6/route.c +5 -2
index 14b422f35504..059f0531f7c1 100644
@@ -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 ||
Signature · 1 line
2.11.0
maintainer
#1 lore raw

From: David Ahern <[email protected]>
Date: Sun, 18 Nov 2018 10:45:30 -0800

Quoted 11 lines

From: David Ahern <[email protected]>

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 ca254490c8df ("net: Add VRF support to IPv6 stack")
Reported-by Preethi Ramachandra <[email protected]>
Signed-off-by David Ahern <[email protected]>

Applied and queued up for -stable.