[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>

1 files changed, 21 insertions, 11 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) */