timewait_sock: Create and use getpeer op.

The only thing AF-specific about remembering the timestamp
for a time-wait TCP socket is getting the peer.

Abstract that behind a new timewait_sock_ops vector.

Support for real IPV6 sockets is not filled in yet, but
curiously this makes timewait recycling start to work
for v4-mapped ipv6 sockets.

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 9 insertions, 0 deletions

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 3e239641d4ee..4097320caa25 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -313,6 +313,7 @@ extern void tcp_shutdown (struct sock *sk, int how);
 extern int tcp_v4_rcv(struct sk_buff *skb);
 
 extern struct inet_peer *tcp_v4_get_peer(struct sock *sk, bool *release_it);
+extern void *tcp_v4_tw_get_peer(struct sock *sk);
 extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
 extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                        size_t size);
diff --git a/include/net/timewait_sock.h b/include/net/timewait_sock.h
index 97c3b14da55d..053b3cf2c66a 100644
--- a/include/net/timewait_sock.h
+++ b/include/net/timewait_sock.h
@@ -21,6 +21,7 @@ struct timewait_sock_ops {
         int             (*twsk_unique)(struct sock *sk,
                                        struct sock *sktw, void *twp);
         void            (*twsk_destructor)(struct sock *sk);
+        void            *(*twsk_getpeer)(struct sock *sk);
 };
 
 static inline int twsk_unique(struct sock *sk, struct sock *sktw, void *twp)
@@ -39,4 +40,11 @@ static inline void twsk_destructor(struct sock *sk)
                 sk->sk_prot->twsk_prot->twsk_destructor(sk);
 }
 
+static inline void *twsk_getpeer(struct sock *sk)
+{
+        if (sk->sk_prot->twsk_prot->twsk_getpeer)
+                return sk->sk_prot->twsk_prot->twsk_getpeer(sk);
+        return NULL;
+}
+
 #endif /* _TIMEWAIT_SOCK_H */