[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;