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>

39 files changed, 277 insertions, 218 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);
diff --git a/include/linux/netfilter.h b/include/linux/netfilter.h
index f8f58fab2402..63560d0a8dfe 100644
--- a/include/linux/netfilter.h
+++ b/include/linux/netfilter.h
@@ -54,7 +54,7 @@ struct nf_hook_state {
         struct net_device *in;
         struct net_device *out;
         struct sock *sk;
-        int (*okfn)(struct sk_buff *);
+        int (*okfn)(struct sock *, struct sk_buff *);
 };
 
 static inline void nf_hook_state_init(struct nf_hook_state *p,
@@ -63,7 +63,7 @@ static inline void nf_hook_state_init(struct nf_hook_state *p,
                                       struct net_device *indev,
                                       struct net_device *outdev,
                                       struct sock *sk,
-                                      int (*okfn)(struct sk_buff *))
+                                      int (*okfn)(struct sock *, struct sk_buff *))
 {
         p->hook = hook;
         p->thresh = thresh;
@@ -156,26 +156,29 @@ int nf_hook_slow(struct sk_buff *skb, struct nf_hook_state *state);
  *      value indicates the packet has been consumed by the hook.
  */
 static inline int nf_hook_thresh(u_int8_t pf, unsigned int hook,
+                                 struct sock *sk,
                                  struct sk_buff *skb,
                                  struct net_device *indev,
                                  struct net_device *outdev,
-                                 int (*okfn)(struct sk_buff *), int thresh)
+                                 int (*okfn)(struct sock *, struct sk_buff *),
+                                 int thresh)
 {
         if (nf_hooks_active(pf, hook)) {
                 struct nf_hook_state state;
 
                 nf_hook_state_init(&state, hook, thresh, pf,
-                                   indev, outdev, NULL, okfn);
+                                   indev, outdev, sk, okfn);
                 return nf_hook_slow(skb, &state);
         }
         return 1;
 }
 
-static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
-                          struct net_device *indev, struct net_device *outdev,
-                          int (*okfn)(struct sk_buff *))
+static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sock *sk,
+                          struct sk_buff *skb, struct net_device *indev,
+                          struct net_device *outdev,
+                          int (*okfn)(struct sock *, struct sk_buff *))
 {
-        return nf_hook_thresh(pf, hook, skb, indev, outdev, okfn, INT_MIN);
+        return nf_hook_thresh(pf, hook, sk, skb, indev, outdev, okfn, INT_MIN);
 }
                    
 /* Activate hook; either okfn or kfree_skb called, unless a hook
@@ -196,35 +199,36 @@ static inline int nf_hook(u_int8_t pf, unsigned int hook, struct sk_buff *skb,
 */
 
 static inline int
-NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sk_buff *skb,
-               struct net_device *in, struct net_device *out,
-               int (*okfn)(struct sk_buff *), int thresh)
+NF_HOOK_THRESH(uint8_t pf, unsigned int hook, struct sock *sk,
+               struct sk_buff *skb, struct net_device *in,
+               struct net_device *out,
+               int (*okfn)(struct sock *, struct sk_buff *), int thresh)
 {
-        int ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, thresh);
+        int ret = nf_hook_thresh(pf, hook, sk, skb, in, out, okfn, thresh);
         if (ret == 1)
-                ret = okfn(skb);
+                ret = okfn(sk, skb);
         return ret;
 }
 
 static inline int
-NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sk_buff *skb,
-             struct net_device *in, struct net_device *out,
+NF_HOOK_COND(uint8_t pf, unsigned int hook, struct sock *sk,
+             struct sk_buff *skb, struct net_device *in, struct net_device *out,