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, 34 insertions, 28 deletions

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,
-	     int (*okfn)(struct sk_buff *), bool cond)
+NF_HOOK_COND(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 *), bool cond)
 {
 	int ret;
 
 	if (!cond ||
-	    ((ret = nf_hook_thresh(pf, hook, skb, in, out, okfn, INT_MIN)) == 1))
-		ret = okfn(skb);
+	    ((ret = nf_hook_thresh(pf, hook, sk, skb, in, out, okfn, INT_MIN)) == 1))
+		ret = okfn(sk, skb);
 	return ret;
 }
 
 static inline int
-NF_HOOK(uint8_t pf, unsigned int hook, struct sk_buff *skb,
+NF_HOOK(uint8_t pf, unsigned int hook, struct sock *sk, struct sk_buff *skb,
 	struct net_device *in, struct net_device *out,
-	int (*okfn)(struct sk_buff *))
+	int (*okfn)(struct sock *, struct sk_buff *))
 {
-	return NF_HOOK_THRESH(pf, hook, skb, in, out, okfn, INT_MIN);
+	return NF_HOOK_THRESH(pf, hook, sk, skb, in, out, okfn, INT_MIN);
 }
 
 /* Call setsockopt() */
@@ -324,19 +328,21 @@ nf_nat_decode_session(struct sk_buff *skb, struct flowi *fl, u_int8_t family)
 }
 
 #else /* !CONFIG_NETFILTER */
-#define NF_HOOK(pf, hook, skb, indev, outdev, okfn) (okfn)(skb)
-#define NF_HOOK_COND(pf, hook, skb, indev, outdev, okfn, cond) (okfn)(skb)
+#define NF_HOOK(pf, hook, sk, skb, indev, outdev, okfn) (okfn)(sk, skb)
+#define NF_HOOK_COND(pf, hook, sk, skb, indev, outdev, okfn, cond) (okfn)(sk, skb)
 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 *sk, struct sk_buff *), int thresh)
 {
-	return okfn(skb);
+	return okfn(sk, skb);
 }
-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 1;
 }