[TCP]: When socket route changes, do not forget to update ext2_header_len and sk_route_caps.

Based upon a patch from Herbert Xu (herbert@gondor.apana.org.au).

net/ipv4/tcp_ipv4.c

@@ -1884,6 +1884,7 @@ static int tcp_v4_reselect_saddr(struct sock *sk)
 
 	__sk_dst_set(sk, &rt->u.dst);
 	tcp_v4_setup_caps(sk, &rt->u.dst);
+	tcp_sk(sk)->ext2_header_len = rt->u.dst.header_len;
 
 	new_saddr = rt->rt_src;
 
@@ -1943,6 +1944,7 @@ int tcp_v4_rebuild_header(struct sock *sk)
 	if (!err) {
 		__sk_dst_set(sk, &rt->u.dst);
 		tcp_v4_setup_caps(sk, &rt->u.dst);
+		tcp_sk(sk)->ext2_header_len = rt->u.dst.header_len;
 		return 0;
 	}
 

net/ipv6/tcp_ipv6.c

@@ -686,7 +686,7 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 
 	ip6_dst_store(sk, dst, NULL);
 	sk->sk_route_caps = dst->dev->features &
-			    ~(NETIF_F_IP_CSUM | NETIF_F_TSO);
+		~(NETIF_F_IP_CSUM | NETIF_F_TSO);
 
 	tp->ext_header_len = 0;
 	if (np->opt)
@@ -1347,8 +1347,8 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 #endif
 
 	ip6_dst_store(newsk, dst, NULL);
-	sk->sk_route_caps = dst->dev->features &
-			    ~(NETIF_F_IP_CSUM | NETIF_F_TSO);
+	newsk->sk_route_caps = dst->dev->features &
+		~(NETIF_F_IP_CSUM | NETIF_F_TSO);
 
 	newtcp6sk = (struct tcp6_sock *)newsk;
 	newtcp6sk->pinet6 = &newtcp6sk->inet6;
@@ -1741,7 +1741,8 @@ static int tcp_v6_rebuild_header(struct sock *sk)
 
 		ip6_dst_store(sk, dst, NULL);
 		sk->sk_route_caps = dst->dev->features &
-				    ~(NETIF_F_IP_CSUM | NETIF_F_TSO);
+			~(NETIF_F_IP_CSUM | NETIF_F_TSO);
+		tcp_sk(sk)->ext2_header_len = dst->header_len;
 	}
 
 	return 0;
@@ -1782,6 +1783,9 @@ static int tcp_v6_xmit(struct sk_buff *skb, int ipfragok)
 		}
 
 		ip6_dst_store(sk, dst, NULL);
+		sk->sk_route_caps = dst->dev->features &
+			~(NETIF_F_IP_CSUM | NETIF_F_TSO);
+		tcp_sk(sk)->ext2_header_len = dst->header_len;
 	}
 
 	skb->dst = dst_clone(dst);