netfilter: Pass socket pointer down through okfn().
On the output paths in particular, we have to sometimes deal with two
socket contexts. First, and usually skb->sk, is the local socket that
generated the frame.
And second, is potentially the socket used to control a tunneling
socket, such as one the encapsulates using UDP.
We do not want to disassociate skb->sk when encapsulating in order
to fix this, because that would break socket memory accounting.
The most extreme case where this can cause huge problems is an
AF_PACKET socket transmitting over a vxlan device. We hit code
paths doing checks that assume they are dealing with an ipv4
socket, but are actually operating upon the AF_PACKET one.
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/ipmr.c b/net/ipv4/ipmr.c
index 5f17d0e..3a2c016 100644
--- a/net/ipv4/ipmr.c
+++ b/net/ipv4/ipmr.c
@@ -1679,7 +1679,7 @@
nf_reset(skb);
}
-static inline int ipmr_forward_finish(struct sk_buff *skb)
+static inline int ipmr_forward_finish(struct sock *sk, struct sk_buff *skb)
{
struct ip_options *opt = &(IPCB(skb)->opt);
@@ -1689,7 +1689,7 @@
if (unlikely(opt->optlen))
ip_forward_options(skb);
- return dst_output(skb);
+ return dst_output_sk(sk, skb);
}
/*
@@ -1788,7 +1788,8 @@
* not mrouter) cannot join to more than one interface - it will
* result in receiving multiple packets.
*/
- NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, skb, skb->dev, dev,
+ NF_HOOK(NFPROTO_IPV4, NF_INET_FORWARD, NULL, skb,
+ skb->dev, dev,
ipmr_forward_finish);
return;