Commit dcd60771 authored Nov 07, 2013 by Eric Dumazet Committed by David S. Miller Nov 08, 2013

inet: fix a UFO regression



While testing virtio_net and skb_segment() changes, Hannes reported
that UFO was sending wrong frames.

It appears this was introduced by a recent commit :
8c3a897b ("inet: restore gso for vxlan")

The old condition to perform IP frag was :

tunnel = !!skb->encapsulation;
...
        if (!tunnel && proto == IPPROTO_UDP) {

So the new one should be :

udpfrag = !skb->encapsulation && proto == IPPROTO_UDP;
...
        if (udpfrag) {

Initialization of udpfrag must be done before call
to ops->callbacks.gso_segment(skb, features), as
skb_udp_tunnel_segment() clears skb->encapsulation

(We want udpfrag to be true for UFO, false for VXLAN)

With help from Alexei Starovoitov

Reported-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 0b2e2d36

net/ipv4/af_inet.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1299,6 +1299,9 @@ static struct sk_buff inet_gso_segment(struct sk_buff skb,

		segs = ERR_PTR(-EPROTONOSUPPORT);

		/* Note : following gso_segment() might change skb->encapsulation */
		udpfrag = !skb->encapsulation && proto == IPPROTO_UDP;

		ops = rcu_dereference(inet_offloads[proto]);
		if (likely(ops && ops->callbacks.gso_segment))
		segs = ops->callbacks.gso_segment(skb, features);
		@@ -1306,7 +1309,6 @@ static struct sk_buff inet_gso_segment(struct sk_buff skb,
		if (IS_ERR_OR_NULL(segs))
		goto out;

		udpfrag = !!skb->encapsulation && proto == IPPROTO_UDP;
		skb = segs;
		do {
		iph = (struct iphdr *)(skb_mac_header(skb) + nhoff);

Admin message