[ICSK]: Generalise tcp_listen_{start,stop}

This also moved inet_iif from tcp to inet_hashtables.h, as it is
needed by the inet_lookup callers, perhaps this needs a bit of
polishing, but for now seems fine.
Signed-off-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/inet_hashtables.h

@@ -26,6 +26,7 @@
 #include <linux/wait.h>
 
 #include <net/inet_connection_sock.h>
+#include <net/route.h>
 #include <net/sock.h>
 #include <net/tcp_states.h>
 
@@ -280,6 +281,11 @@ static inline void inet_unhash(struct inet_hashinfo *hashinfo, struct sock *sk)
 		wake_up(&hashinfo->lhash_wait);
 }
 
+static inline int inet_iif(const struct sk_buff *skb)
+{
+	return ((struct rtable *)skb->dst)->rt_iif;
+}
+
 extern struct sock *__inet_lookup_listener(const struct hlist_head *head,
 					   const u32 daddr,
 					   const unsigned short hnum,

include/net/sock.h

@@ -558,6 +558,7 @@ struct proto {
 
 	kmem_cache_t		*twsk_slab;
 	unsigned int		twsk_obj_size;
+	atomic_t		*orphan_count;
 
 	struct request_sock_ops	*rsk_prot;
 

include/net/tcp.h

@@ -860,7 +860,7 @@ static __inline__ void tcp_update_wl(struct tcp_sock *tp, u32 ack, u32 seq)
 	tp->snd_wl1 = seq;
 }
 
-extern void tcp_destroy_sock(struct sock *sk);
+extern void inet_csk_destroy_sock(struct sock *sk);
 
 
 /*
@@ -987,7 +987,7 @@ static __inline__ void tcp_done(struct sock *sk)
 	if (!sock_flag(sk, SOCK_DEAD))
 		sk->sk_state_change(sk);
 	else
-		tcp_destroy_sock(sk);
+		inet_csk_destroy_sock(sk);
 }
 
 static __inline__ void tcp_sack_reset(struct tcp_options_received *rx_opt)

net/ipv4/af_inet.c

@@ -202,7 +202,7 @@ int inet_listen(struct socket *sock, int backlog)
 	 * we can only allow the backlog to be adjusted.
 	 */
 	if (old_state != TCP_LISTEN) {
-		err = tcp_listen_start(sk);
+		err = inet_csk_listen_start(sk, TCP_SYNQ_HSIZE);
 		if (err)
 			goto out;
 	}

net/ipv4/tcp.c

@@ -273,6 +273,8 @@ DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics);
 
 atomic_t tcp_orphan_count = ATOMIC_INIT(0);
 
+EXPORT_SYMBOL_GPL(tcp_orphan_count);
+
 int sysctl_tcp_mem[3];
 int sysctl_tcp_wmem[3] = { 4 * 1024, 16 * 1024, 128 * 1024 };
 int sysctl_tcp_rmem[3] = { 4 * 1024, 87380, 87380 * 2 };
@@ -454,12 +456,11 @@ int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
 	return put_user(answ, (int __user *)arg);
 }
 
-
-int tcp_listen_start(struct sock *sk)
+int inet_csk_listen_start(struct sock *sk, const int nr_table_entries)
 {
 	struct inet_sock *inet = inet_sk(sk);
 	struct inet_connection_sock *icsk = inet_csk(sk);
-	int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, TCP_SYNQ_HSIZE);
+	int rc = reqsk_queue_alloc(&icsk->icsk_accept_queue, nr_table_entries);
 
 	if (rc != 0)
 		return rc;
@@ -488,12 +489,13 @@ int tcp_listen_start(struct sock *sk)
 	return -EADDRINUSE;
 }
 
+EXPORT_SYMBOL_GPL(inet_csk_listen_start);
+
 /*
  *	This routine closes sockets which have been at least partially
  *	opened, but not yet accepted.
  */
-
-static void tcp_listen_stop (struct sock *sk)
+static void inet_csk_listen_stop(struct sock *sk)
 {
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct request_sock *acc_req;
@@ -524,13 +526,13 @@ static void tcp_listen_stop (struct sock *sk)
 		BUG_TRAP(!sock_owned_by_user(child));
 		sock_hold(child);
 
-		tcp_disconnect(child, O_NONBLOCK);
+		sk->sk_prot->disconnect(child, O_NONBLOCK);
 
 		sock_orphan(child);
 
-		atomic_inc(&tcp_orphan_count);
+		atomic_inc(sk->sk_prot->orphan_count);
 
-		tcp_destroy_sock(child);
+		inet_csk_destroy_sock(child);
 
 		bh_unlock_sock(child);
 		local_bh_enable();
@@ -542,6 +544,8 @@ static void tcp_listen_stop (struct sock *sk)
 	BUG_TRAP(!sk->sk_ack_backlog);
 }
 
+EXPORT_SYMBOL_GPL(inet_csk_listen_stop);
+
 static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
 {
 	TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
@@ -1561,7 +1565,7 @@ void tcp_shutdown(struct sock *sk, int how)
  * can assume the socket waitqueue is inactive and nobody will
  * try to jump onto it.
  */
-void tcp_destroy_sock(struct sock *sk)
+void inet_csk_destroy_sock(struct sock *sk)
 {
 	BUG_TRAP(sk->sk_state == TCP_CLOSE);
 	BUG_TRAP(sock_flag(sk, SOCK_DEAD));
@@ -1580,7 +1584,7 @@ void tcp_destroy_sock(struct sock *sk)
 
 	sk_refcnt_debug_release(sk);
 
-	atomic_dec(&tcp_orphan_count);
+	atomic_dec(sk->sk_prot->orphan_count);
 	sock_put(sk);
 }
 
@@ -1596,7 +1600,7 @@ void tcp_close(struct sock *sk, long timeout)
 		tcp_set_state(sk, TCP_CLOSE);
 
 		/* Special case. */
-		tcp_listen_stop(sk);
+		inet_csk_listen_stop(sk);
 
 		goto adjudge_to_death;
 	}
@@ -1704,7 +1708,7 @@ void tcp_close(struct sock *sk, long timeout)
 			if (tmo > TCP_TIMEWAIT_LEN) {
 				inet_csk_reset_keepalive_timer(sk, tcp_fin_time(sk));
 			} else {
-				atomic_inc(&tcp_orphan_count);
+				atomic_inc(sk->sk_prot->orphan_count);
 				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
 				goto out;
 			}
@@ -1712,7 +1716,7 @@ void tcp_close(struct sock *sk, long timeout)
 	}
 	if (sk->sk_state != TCP_CLOSE) {
 		sk_stream_mem_reclaim(sk);
-		if (atomic_read(&tcp_orphan_count) > sysctl_tcp_max_orphans ||
+		if (atomic_read(sk->sk_prot->orphan_count) > sysctl_tcp_max_orphans ||
 		    (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
 		     atomic_read(&tcp_memory_allocated) > sysctl_tcp_mem[2])) {
 			if (net_ratelimit())
@@ -1723,10 +1727,10 @@ void tcp_close(struct sock *sk, long timeout)
 			NET_INC_STATS_BH(LINUX_MIB_TCPABORTONMEMORY);
 		}
 	}
-	atomic_inc(&tcp_orphan_count);
+	atomic_inc(sk->sk_prot->orphan_count);
 
 	if (sk->sk_state == TCP_CLOSE)
-		tcp_destroy_sock(sk);
+		inet_csk_destroy_sock(sk);
 	/* Otherwise, socket is reprieved until protocol close. */
 
 out:
@@ -1757,7 +1761,7 @@ int tcp_disconnect(struct sock *sk, int flags)
 
 	/* ABORT function of RFC793 */
 	if (old_state == TCP_LISTEN) {
-		tcp_listen_stop(sk);
+		inet_csk_listen_stop(sk);
 	} else if (tcp_need_reset(old_state) ||
 		   (tp->snd_nxt != tp->write_seq &&
 		    (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
@@ -2253,7 +2257,7 @@ void __init tcp_init(void)
 }
 
 EXPORT_SYMBOL(tcp_close);
-EXPORT_SYMBOL(tcp_destroy_sock);
+EXPORT_SYMBOL(inet_csk_destroy_sock);
 EXPORT_SYMBOL(tcp_disconnect);
 EXPORT_SYMBOL(tcp_getsockopt);
 EXPORT_SYMBOL(tcp_ioctl);

net/ipv4/tcp_ipv4.c

@@ -431,11 +431,6 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	return err;
 }
 
-static inline int inet_iif(const struct sk_buff *skb)
-{
-	return ((struct rtable *)skb->dst)->rt_iif;
-}
-
 /*
  * This routine does path mtu discovery as defined in RFC1191.
  */
@@ -1993,6 +1988,7 @@ struct proto tcp_prot = {
 	.get_port		= tcp_v4_get_port,
 	.enter_memory_pressure	= tcp_enter_memory_pressure,
 	.sockets_allocated	= &tcp_sockets_allocated,
+	.orphan_count		= &tcp_orphan_count,
 	.memory_allocated	= &tcp_memory_allocated,
 	.memory_pressure	= &tcp_memory_pressure,
 	.sysctl_mem		= sysctl_tcp_mem,

net/ipv6/tcp_ipv6.c

@@ -2248,6 +2248,7 @@ struct proto tcpv6_prot = {
 	.sockets_allocated	= &tcp_sockets_allocated,
 	.memory_allocated	= &tcp_memory_allocated,
 	.memory_pressure	= &tcp_memory_pressure,
+	.orphan_count		= &tcp_orphan_count,
 	.sysctl_mem		= sysctl_tcp_mem,
 	.sysctl_wmem		= sysctl_tcp_wmem,
 	.sysctl_rmem		= sysctl_tcp_rmem,