Commit 850dcc4d authored by Eric W. Biederman's avatar Eric W. Biederman Committed by David S. Miller

ipv4: Fix ip_queue_xmit to pass sk into ip_local_out_sk

After a packet has been encapsulated by a tunnel we should use the
tunnel sockets local multicast loopback flag to control if the
encapsulated packet should be locally loopback back.

Pass sk into ip_local_out_sk so that in the rare case we are dealing
with a tunneled packet whose tunnel destination address is a multicast
address the kernel properly decides to loopback this packet.

In practice I don't think this matters as ip_queue_xmit is used by
tcp, l2tp and sctp none of which I am aware of uses ip level
multicasting as they are all point to point communications protocols.
Let's fix this before someone uses ip_queue_xmit for a tunnel protocol
that does use multicast.

Fixes: aad88724 ("ipv4: add a sock pointer to dst->output() path.")
Fixes: b0270e91 ("ipv4: add a sock pointer to ip_queue_xmit()")
Signed-off-by: default avatar"Eric W. Biederman" <>
Signed-off-by: default avatarDavid S. Miller <>
parent fd2874b3
......@@ -460,7 +460,7 @@ packet_routed:
skb->priority = sk->sk_priority;
skb->mark = sk->sk_mark;
res = ip_local_out(skb);
res = ip_local_out_sk(sk, skb);
return res;
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