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>

1 files changed, 11 insertions, 3 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 41bf58a2b936..45823db2efb0 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2165,8 +2165,12 @@ int dev_open(struct net_device *dev);
 int dev_close(struct net_device *dev);
 int dev_close_many(struct list_head *head, bool unlink);
 void dev_disable_lro(struct net_device *dev);
-int dev_loopback_xmit(struct sk_buff *newskb);
-int dev_queue_xmit(struct sk_buff *skb);
+int dev_loopback_xmit(struct sock *sk, struct sk_buff *newskb);
+int dev_queue_xmit_sk(struct sock *sk, struct sk_buff *skb);
+static inline int dev_queue_xmit(struct sk_buff *skb)
+{
+        return dev_queue_xmit_sk(skb->sk, skb);
+}
 int dev_queue_xmit_accel(struct sk_buff *skb, void *accel_priv);
 int register_netdevice(struct net_device *dev);
 void unregister_netdevice_queue(struct net_device *dev, struct list_head *head);
@@ -2927,7 +2931,11 @@ static inline void dev_consume_skb_any(struct sk_buff *skb)
 
 int netif_rx(struct sk_buff *skb);
 int netif_rx_ni(struct sk_buff *skb);
-int netif_receive_skb(struct sk_buff *skb);
+int netif_receive_skb_sk(struct sock *sk, struct sk_buff *skb);
+static inline int netif_receive_skb(struct sk_buff *skb)
+{
+        return netif_receive_skb_sk(skb->sk, skb);
+}
 gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb);
 void napi_gro_flush(struct napi_struct *napi, bool flush_old);
 struct sk_buff *napi_get_frags(struct napi_struct *napi);