[IPV6]: Introduce inet6_timewait_sock

Out of tcp6_timewait_sock, that now is just an aggregation of
inet_timewait_sock and inet6_timewait_sock, using tw_ipv6_offset in struct
inet_timewait_sock, that is common to the IPv6 transport protocols that use
timewait sockets, like DCCP and TCP.

tw_ipv6_offset plays the struct inet_sock pinfo6 role, i.e. for the generic
code to find the IPv6 area in a timewait sock.

Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 26 insertions, 15 deletions

diff --git a/include/linux/ipv6.h b/include/linux/ipv6.h
index 69a0decfbdf4..7d3908594fac 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -348,26 +348,36 @@ static inline void inet_sk_copy_descendant(struct sock *sk_to,
 
 #include <linux/tcp.h>
 
+struct inet6_timewait_sock {
+	struct in6_addr tw_v6_daddr;
+	struct in6_addr	tw_v6_rcv_saddr;
+};
+
 struct tcp6_timewait_sock {
-	struct tcp_timewait_sock tw_v6_sk;
-	struct in6_addr		 tw_v6_daddr;
-	struct in6_addr		 tw_v6_rcv_saddr;
+	struct tcp_timewait_sock   tcp6tw_tcp;
+	struct inet6_timewait_sock tcp6tw_inet6;
 };
 
-static inline struct tcp6_timewait_sock *tcp6_twsk(const struct sock *sk)
+static inline u16 inet6_tw_offset(const struct proto *prot)
+{
+	return prot->twsk_obj_size - sizeof(struct inet6_timewait_sock);
+}
+
+static inline struct inet6_timewait_sock *inet6_twsk(const struct sock *sk)
 {
-	return (struct tcp6_timewait_sock *)sk;
+	return (struct inet6_timewait_sock *)(((u8 *)sk) +
+					      inet_twsk(sk)->tw_ipv6_offset);
 }
 
-static inline struct in6_addr *__tcp_v6_rcv_saddr(const struct sock *sk)
+static inline struct in6_addr *__inet6_rcv_saddr(const struct sock *sk)
 {
 	return likely(sk->sk_state != TCP_TIME_WAIT) ?
-		&inet6_sk(sk)->rcv_saddr : &tcp6_twsk(sk)->tw_v6_rcv_saddr;
+		&inet6_sk(sk)->rcv_saddr : &inet6_twsk(sk)->tw_v6_rcv_saddr;
 }
 
-static inline struct in6_addr *tcp_v6_rcv_saddr(const struct sock *sk)
+static inline struct in6_addr *inet6_rcv_saddr(const struct sock *sk)
 {
-	return sk->sk_family == AF_INET6 ? __tcp_v6_rcv_saddr(sk) : NULL;
+	return sk->sk_family == AF_INET6 ? __inet6_rcv_saddr(sk) : NULL;
 }
 
 static inline int inet_v6_ipv6only(const struct sock *sk)
@@ -395,8 +405,8 @@ static inline struct raw6_sock *raw6_sk(const struct sock *sk)
 	return NULL;
 }
 
-#define __tcp_v6_rcv_saddr(__sk)	NULL
-#define tcp_v6_rcv_saddr(__sk)		NULL
+#define __inet6_rcv_saddr(__sk)	NULL
+#define inet6_rcv_saddr(__sk)	NULL
 #define tcp_twsk_ipv6only(__sk)		0
 #define inet_v6_ipv6only(__sk)		0
 #endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h
index a4a204f99ea6..25f708ff020e 100644
--- a/include/net/inet6_hashtables.h
+++ b/include/net/inet6_hashtables.h
@@ -110,10 +110,10 @@ static inline struct sock *
 
 		if(*((__u32 *)&(tw->tw_dport))	== ports	&&
 		   sk->sk_family		== PF_INET6) {
-			const struct tcp6_timewait_sock *tcp6tw = tcp6_twsk(sk);
+			const struct inet6_timewait_sock *tw6 = inet6_twsk(sk);
 
-			if (ipv6_addr_equal(&tcp6tw->tw_v6_daddr, saddr)	&&
-			    ipv6_addr_equal(&tcp6tw->tw_v6_rcv_saddr, daddr)	&&
+			if (ipv6_addr_equal(&tw6->tw_v6_daddr, saddr)	&&
+			    ipv6_addr_equal(&tw6->tw_v6_rcv_saddr, daddr)	&&
 			    (!sk->sk_bound_dev_if || sk->sk_bound_dev_if == dif))
 				goto hit;
 		}
diff --git a/include/net/inet_timewait_sock.h b/include/net/inet_timewait_sock.h
index 28f7b2103505..ca240f856c46 100644
--- a/include/net/inet_timewait_sock.h
+++ b/include/net/inet_timewait_sock.h
@@ -127,7 +127,8 @@ struct inet_timewait_sock {
 	__u16			tw_num;
 	/* And these are ours. */
 	__u8			tw_ipv6only:1;
-	/* 31 bits hole, try to pack */
+	/* 15 bits hole, try to pack */
+	__u16			tw_ipv6_offset;
 	int			tw_timeout;
 	unsigned long		tw_ttd;
 	struct inet_bind_bucket	*tw_tb;