Allow to bind to an already in use local port

during connect when the connection will still have a unique
identity.  Fixes port space exhaustion, especially in web
caches.

Initial work done by Andi Kleen.

Documentation/networking/ip-sysctl.txt

@@ -126,7 +126,13 @@ tcp_max_tw_buckets - INTEGER
 	if network conditions require more than default value.
 
 tcp_tw_recycle - BOOLEAN
-	Enable fast recycling TIME-WAIT sockets. Default value is 1.
+	Enable fast recycling TIME-WAIT sockets. Default value is 0.
+	It should not be changed without advice/request of technical
+	experts.
+
+tcp_tw_reuse - BOOLEAN
+	Allow to reuse TIME-WAIT sockets for new connections when it is
+	safe from protocol viewpoint. Default value is 0.
 	It should not be changed without advice/request of technical
 	experts.
 

include/linux/sysctl.h

@@ -288,7 +288,8 @@ enum
 	NET_TCP_ADV_WIN_SCALE=87,
 	NET_IPV4_NONLOCAL_BIND=88,
 	NET_IPV4_ICMP_RATELIMIT=89,
-	NET_IPV4_ICMP_RATEMASK=90
+	NET_IPV4_ICMP_RATEMASK=90,
+	NET_TCP_TW_REUSE=91
 };
 
 enum {

include/net/tcp.h

@@ -78,7 +78,7 @@ struct tcp_ehash_bucket {
  */
 struct tcp_bind_bucket {
 	unsigned short		port;
-	unsigned short		fastreuse;
+	signed short		fastreuse;
 	struct tcp_bind_bucket	*next;
 	struct sock		*owners;
 	struct tcp_bind_bucket	**pprev;
@@ -469,6 +469,7 @@ extern int sysctl_tcp_wmem[3];
 extern int sysctl_tcp_rmem[3];
 extern int sysctl_tcp_app_win;
 extern int sysctl_tcp_adv_win_scale;
+extern int sysctl_tcp_tw_reuse;
 
 extern atomic_t tcp_memory_allocated;
 extern atomic_t tcp_sockets_allocated;
@@ -578,8 +579,6 @@ struct tcp_func {
 							 struct open_request *req,
 							 struct dst_entry *dst);
     
-	int			(*hash_connecting)	(struct sock *sk);
-
 	int			(*remember_stamp)	(struct sock *sk);
 
 	__u16			net_header_len;
@@ -781,8 +780,7 @@ extern int			tcp_v4_connect(struct sock *sk,
 					       struct sockaddr *uaddr,
 					       int addr_len);
 
-extern int			tcp_connect(struct sock *sk,
-					    struct sk_buff *skb);
+extern int			tcp_connect(struct sock *sk);
 
 extern struct sk_buff *		tcp_make_synack(struct sock *sk,
 						struct dst_entry *dst,

net/ipv4/af_inet.c

@@ -655,13 +655,6 @@ int inet_stream_connect(struct socket *sock, struct sockaddr * uaddr,
 		if (sk->state != TCP_CLOSE) 
 			goto out;
 
-		err = -EAGAIN;
-		if (!inet->num) {
-			if (sk->prot->get_port(sk, 0) != 0)
-				goto out;
-			inet->sport = htons(inet->num);
-		}
-
 		err = sk->prot->connect(sk, uaddr, addr_len);
 		if (err < 0)
 			goto out;

net/ipv4/sysctl_net_ipv4.c

@@ -219,6 +219,8 @@ ctl_table ipv4_table[] = {
 	 &sysctl_icmp_ratelimit, sizeof(int), 0644, NULL, &proc_dointvec},
 	{NET_IPV4_ICMP_RATEMASK, "icmp_ratemask",
 	 &sysctl_icmp_ratemask, sizeof(int), 0644, NULL, &proc_dointvec},
+	{NET_TCP_TW_REUSE, "tcp_tw_reuse",
+	 &sysctl_tcp_tw_reuse, sizeof(int), 0644, NULL, &proc_dointvec},
 	{0}
 };
 

net/ipv4/tcp_ipv4.c

@@ -64,6 +64,7 @@
 #include <linux/ipsec.h>
 
 extern int sysctl_ip_dynaddr;
+int sysctl_tcp_tw_reuse = 0;
 
 /* Check TCP sequence numbers in ICMP packets. */
 #define ICMP_MIN_LENGTH 8
@@ -247,7 +248,9 @@ static int tcp_v4_get_port(struct sock *sk, unsigned short snum)
 				break;
 	}
 	if (tb != NULL && tb->owners != NULL) {
-		if (tb->fastreuse != 0 && sk->reuse != 0 && sk->state != TCP_LISTEN) {
+		if (sk->reuse > 1)
+			goto success;
+		if (tb->fastreuse > 0 && sk->reuse != 0 && sk->state != TCP_LISTEN) {
 			goto success;
 		} else {
 			ret = 1;
@@ -341,13 +344,13 @@ void tcp_listen_wlock(void)
 	}
 }
 
-static __inline__ void __tcp_v4_hash(struct sock *sk)
+static __inline__ void __tcp_v4_hash(struct sock *sk, const int listen_possible)
 {
 	struct sock **skp;
 	rwlock_t *lock;
 
 	BUG_TRAP(sk->pprev==NULL);
-	if(sk->state == TCP_LISTEN) {
+	if(listen_possible && sk->state == TCP_LISTEN) {
 		skp = &tcp_listening_hash[tcp_sk_listen_hashfn(sk)];
 		lock = &tcp_lhash_lock;
 		tcp_listen_wlock();
@@ -362,7 +365,7 @@ static __inline__ void __tcp_v4_hash(struct sock *sk)
 	sk->pprev = skp;
 	sock_prot_inc_use(sk->prot);
 	write_unlock(lock);
-	if (sk->state == TCP_LISTEN)
+	if (listen_possible && sk->state == TCP_LISTEN)
 		wake_up(&tcp_lhash_wait);
 }
 
@@ -370,7 +373,7 @@ static void tcp_v4_hash(struct sock *sk)
 {
 	if (sk->state != TCP_CLOSE) {
 		local_bh_disable();
-		__tcp_v4_hash(sk);
+		__tcp_v4_hash(sk, 1);
 		local_bh_enable();
 	}
 }
@@ -379,6 +382,9 @@ void tcp_unhash(struct sock *sk)
 {
 	rwlock_t *lock;
 
+	if (!sk->pprev)
+		goto ende;
+
 	if (sk->state == TCP_LISTEN) {
 		local_bh_disable();
 		tcp_listen_wlock();
@@ -397,6 +403,8 @@ void tcp_unhash(struct sock *sk)
 		sock_prot_dec_use(sk->prot);
 	}
 	write_unlock_bh(lock);
+
+ ende:
 	if (sk->state == TCP_LISTEN)
 		wake_up(&tcp_lhash_wait);
 }
@@ -538,20 +546,22 @@ static inline __u32 tcp_v4_init_sequence(struct sock *sk, struct sk_buff *skb)
 					  skb->h.th->source);
 }
 
-static int tcp_v4_check_established(struct sock *sk)
+/* called with local bh disabled */
+static int __tcp_v4_check_established(struct sock *sk, __u16 lport,
+				      struct tcp_tw_bucket **twp)
 {
 	struct inet_opt *inet = inet_sk(sk);
 	u32 daddr = inet->rcv_saddr;
 	u32 saddr = inet->daddr;
 	int dif = sk->bound_dev_if;
 	TCP_V4_ADDR_COOKIE(acookie, saddr, daddr)
-	__u32 ports = TCP_COMBINED_PORTS(inet->dport, inet->num);
-	int hash = tcp_hashfn(daddr, inet->num, saddr, inet->dport);
+	__u32 ports = TCP_COMBINED_PORTS(inet->dport, lport);
+	int hash = tcp_hashfn(daddr, lport, saddr, inet->dport);
 	struct tcp_ehash_bucket *head = &tcp_ehash[hash];
 	struct sock *sk2, **skp;
 	struct tcp_tw_bucket *tw;
 
-	write_lock_bh(&head->lock);
+	write_lock(&head->lock);
 
 	/* Check TIME-WAIT sockets first. */
 	for(skp = &(head + tcp_ehash_size)->chain; (sk2=*skp) != NULL;
@@ -575,7 +585,9 @@ static int tcp_v4_check_established(struct sock *sk)
 			   fall back to VJ's scheme and use initial
 			   timestamp retrieved from peer table.
 			 */
-			if (tw->ts_recent_stamp) {
+			if (tw->ts_recent_stamp &&
+			    (!twp || (sysctl_tcp_tw_reuse &&
+				      xtime.tv_sec - tw->ts_recent_stamp > 1))) {
 				if ((tp->write_seq =
 						tw->snd_nxt + 65535 + 2) == 0)
 					tp->write_seq = 1;
@@ -597,6 +609,10 @@ static int tcp_v4_check_established(struct sock *sk)
 	}
 
 unique:
+	/* Must record num and sport now. Otherwise we will see
+	 * in hash table socket with a funny identity. */
+	sk->num = lport;
+	sk->sport = htons(lport);
 	BUG_TRAP(sk->pprev==NULL);
 	if ((sk->next = *skp) != NULL)
 		(*skp)->pprev = &sk->next;
@@ -605,15 +621,16 @@ static int tcp_v4_check_established(struct sock *sk)
 	sk->pprev = skp;
 	sk->hashent = hash;
 	sock_prot_inc_use(sk->prot);
-	write_unlock_bh(&head->lock);
+	write_unlock(&head->lock);
 
-	if (tw) {
+	if (twp) {
+		*twp = tw;
+		NET_INC_STATS_BH(TimeWaitRecycled);
+	} else if (tw) {
 		/* Silly. Should hash-dance instead... */
-		local_bh_disable();
 		tcp_tw_deschedule(tw);
 		tcp_timewait_kill(tw);
 		NET_INC_STATS_BH(TimeWaitRecycled);
-		local_bh_enable();
 
 		tcp_tw_put(tw);
 	}
@@ -621,34 +638,120 @@ static int tcp_v4_check_established(struct sock *sk)
 	return 0;
 
 not_unique:
-	write_unlock_bh(&head->lock);
+	write_unlock(&head->lock);
 	return -EADDRNOTAVAIL;
 }
 
-/* Hash SYN-SENT socket to established hash table after
- * checking that it is unique. Note, that without kernel lock
- * we MUST make these two operations atomically.
- *
- * Optimization: if it is bound and tcp_bind_bucket has the only
- * owner (us), we need not to scan established bucket.
+/*
+ * Bind a port for a connect operation and hash it.
  */
-
-int tcp_v4_hash_connecting(struct sock *sk)
+static int tcp_v4_hash_connect(struct sock *sk)
 {
 	unsigned short snum = inet_sk(sk)->num;
-	struct tcp_bind_hashbucket *head = &tcp_bhash[tcp_bhashfn(snum)];
-	struct tcp_bind_bucket *tb = (struct tcp_bind_bucket *)sk->prev;
+ 	struct tcp_bind_hashbucket *head;
+ 	struct tcp_bind_bucket *tb;
+ 
+ 	if (snum == 0) {
+ 		int rover;
+ 		int low = sysctl_local_port_range[0];
+ 		int high = sysctl_local_port_range[1];
+ 		int remaining = (high - low) + 1;
+ 		struct tcp_tw_bucket *tw = NULL;
+ 
+ 		local_bh_disable();
+ 
+ 		/* TODO. Actually it is not so bad idea to remove
+ 		 * tcp_portalloc_lock before next submission to Linus.
+ 		 * As soon as we touch this place at all it is time to think.
+ 		 *
+ 		 * Now it protects single _advisory_ variable tcp_port_rover,
+ 		 * hence it is mostly useless.
+ 		 * Code will work nicely if we just delete it, but
+ 		 * I am afraid in contented case it will work not better or
+ 		 * even worse: another cpu just will hit the same bucket
+ 		 * and spin there.
+ 		 * So some cpu salt could remove both contention and
+ 		 * memory pingpong. Any ideas how to do this in a nice way?
+ 		 */
+ 		spin_lock(&tcp_portalloc_lock);
+ 		rover = tcp_port_rover;
+ 
+ 		do {
+ 			rover++;
+ 			if ((rover < low) || (rover > high))
+ 				rover = low;
+ 			head = &tcp_bhash[tcp_bhashfn(rover)];
+ 			spin_lock(&head->lock);		
+ 
+ 			/* Does not bother with rcv_saddr checks,
+ 			 * because the established check is already
+ 			 * unique enough.
+ 			 */
+ 			for (tb = head->chain; tb; tb = tb->next) {
+ 				if (tb->port == rover) {
+ 					BUG_TRAP(tb->owners != NULL);
+ 					if (tb->fastreuse >= 0)
+ 						goto next_port;
+ 					if (!__tcp_v4_check_established(sk, rover, &tw))
+ 						goto ok;
+ 					goto next_port;
+ 				}
+ 			}
+ 
+ 			tb = tcp_bucket_create(head, rover);
+ 			if (!tb) {
+ 				spin_unlock(&head->lock);
+ 				break;
+ 			}
+ 			tb->fastreuse = -1;
+ 			goto ok;
+ 
+ 		next_port:
+ 			spin_unlock(&head->lock);
+ 		} while (--remaining > 0);
+ 		tcp_port_rover = rover;
+ 		spin_unlock(&tcp_portalloc_lock);
+ 
+ 		local_bh_enable();
+ 
+ 		return -EADDRNOTAVAIL;
+ 
+ 	ok:
+ 		/* All locks still held and bhs disabled */
+ 		tcp_port_rover = rover;
+ 		spin_unlock(&tcp_portalloc_lock);
  
+ 		tcp_bind_hash(sk, tb, rover);
+ 		if (!sk->pprev) {
+ 			sk->sport = htons(rover);
+ 			__tcp_v4_hash(sk, 0);
+ 		}
+ 		spin_unlock(&head->lock);
+
+ 		if (tw) {
+ 			tcp_tw_deschedule(tw);
+ 			tcp_timewait_kill(tw);
+ 			tcp_tw_put(tw);
+ 		}
+ 
+ 		local_bh_enable();
+ 		return 0;
+ 	}
+ 
+ 	head  = &tcp_bhash[tcp_bhashfn(snum)];
+ 	tb  = (struct tcp_bind_bucket *)sk->prev;
 	spin_lock_bh(&head->lock);
 	if (tb->owners == sk && sk->bind_next == NULL) {
-		__tcp_v4_hash(sk);
+		__tcp_v4_hash(sk, 0);
 		spin_unlock_bh(&head->lock);
 		return 0;
 	} else {
-		spin_unlock_bh(&head->lock);
-
+		int ret;
+		spin_unlock(&head->lock);
 		/* No definite answer... Walk to established hash table */
-		return tcp_v4_check_established(sk);
+		ret = __tcp_v4_check_established(sk, snum, NULL);
+		local_bh_enable();
+		return ret;
 	}
 }
 
@@ -658,7 +761,6 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	struct inet_opt *inet = inet_sk(sk);
 	struct tcp_opt *tp = tcp_sk(sk);
 	struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
-	struct sk_buff *buff;
 	struct rtable *rt;
 	u32 daddr, nexthop;
 	int tmp;
@@ -693,12 +795,6 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	if (!inet->opt || !inet->opt->srr)
 		daddr = rt->rt_dst;
 
-	err = -ENOBUFS;
-	buff = alloc_skb(MAX_TCP_HEADER + 15, sk->allocation);
-
-	if (buff == NULL)
-		goto failure;
-
 	if (!inet->saddr)
 		inet->saddr = rt->rt_src;
 	inet->rcv_saddr = inet->saddr;
@@ -729,24 +825,38 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	inet->dport = usin->sin_port;
 	inet->daddr = daddr;
 
+	tp->ext_header_len = 0;
+	if (inet->opt)
+		tp->ext_header_len = inet->opt->optlen;
+
+	tp->mss_clamp = 536;
+
+	/* Socket identity is still unknown (sport may be zero).
+	 * However we set state to SYN-SENT and not releasing socket
+	 * lock select source port, enter ourselves into the hash tables and
+	 * complete initalization after this.
+	 */
+	tcp_set_state(sk, TCP_SYN_SENT);
+	err = tcp_v4_hash_connect(sk);
+	if (err)
+		goto failure;
+
 	if (!tp->write_seq)
 		tp->write_seq = secure_tcp_sequence_number(inet->saddr,
 							   inet->daddr,
 							   inet->sport,
 							   usin->sin_port);
 
-	tp->ext_header_len = 0;
-	if (inet->opt)
-		tp->ext_header_len = inet->opt->optlen;
 	inet->id = tp->write_seq ^ jiffies;
 
-	tp->mss_clamp = 536;
+	err = tcp_connect(sk);
+	if (err)
+		goto failure;
 
-	err = tcp_connect(sk, buff);
-	if (err == 0)
 	return 0;
 
 failure:
+	tcp_set_state(sk, TCP_CLOSE);
 	__sk_dst_reset(sk);
 	sk->route_caps = 0;
 	inet->dport = 0;
@@ -1477,7 +1587,7 @@ struct sock * tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 	newtp->advmss = dst->advmss;
 	tcp_initialize_rcv_mss(newsk);
 
-	__tcp_v4_hash(newsk);
+	__tcp_v4_hash(newsk, 0);
 	__tcp_inherit_port(sk, newsk);
 
 	return newsk;
@@ -1901,7 +2011,6 @@ struct tcp_func ipv4_specific = {
 	tcp_v4_rebuild_header,
 	tcp_v4_conn_request,
 	tcp_v4_syn_recv_sock,
-	tcp_v4_hash_connecting,
 	tcp_v4_remember_stamp,
 	sizeof(struct iphdr),
 

net/ipv4/tcp_output.c

@@ -38,6 +38,7 @@
 
 #include <net/tcp.h>
 
+#include <linux/compiler.h>
 #include <linux/smp_lock.h>
 
 /* People can turn this off for buggy TCP's found in printers etc. */
@@ -1156,14 +1157,14 @@ struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
 	return skb;
 }
 
-int tcp_connect(struct sock *sk, struct sk_buff *buff)
+/* 
+ * Do all connect socket setups that can be done AF independent.
+ */ 
+static inline void tcp_connect_init(struct sock *sk)
 {
 	struct dst_entry *dst = __sk_dst_get(sk);
 	struct tcp_opt *tp = tcp_sk(sk);
 
-	/* Reserve space for headers. */
-	skb_reserve(buff, MAX_TCP_HEADER);
-
 	/* We'll fix this up when we get a response from the other end.
 	 * See tcp_input.c:tcp_rcv_state_process case TCP_SYN_SENT.
 	 */
@@ -1190,14 +1191,6 @@ int tcp_connect(struct sock *sk, struct sk_buff *buff)
 
 	tp->rcv_ssthresh = tp->rcv_wnd;
 
-	/* Socket identity change complete, no longer
-	 * in TCP_CLOSE, so enter ourselves into the
-	 * hash tables.
-	 */
-	tcp_set_state(sk,TCP_SYN_SENT);
-	if (tp->af_specific->hash_connecting(sk))
-		goto err_out;
-
 	sk->err = 0;
 	sk->done = 0;
 	tp->snd_wnd = 0;
@@ -1211,6 +1204,24 @@ int tcp_connect(struct sock *sk, struct sk_buff *buff)
 	tp->rto = TCP_TIMEOUT_INIT;
 	tp->retransmits = 0;
 	tcp_clear_retrans(tp);
+}
+
+/*
+ * Build a SYN and send it off.
+ */ 
+int tcp_connect(struct sock *sk)
+{
+	struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
+	struct sk_buff *buff;
+
+	tcp_connect_init(sk);
+
+	buff = alloc_skb(MAX_TCP_HEADER + 15, sk->allocation);
+	if (unlikely(buff == NULL))
+		return -ENOBUFS;
+
+	/* Reserve space for headers. */
+	skb_reserve(buff, MAX_TCP_HEADER);
 
 	TCP_SKB_CB(buff)->flags = TCPCB_FLAG_SYN;
 	TCP_ECN_send_syn(tp, buff);
@@ -1233,11 +1244,6 @@ int tcp_connect(struct sock *sk, struct sk_buff *buff)
 	/* Timer for repeating the SYN until an answer. */
 	tcp_reset_xmit_timer(sk, TCP_TIME_RETRANS, tp->rto);
 	return 0;
-
-err_out:
-	tcp_set_state(sk,TCP_CLOSE);
-	kfree_skb(buff);
-	return -EADDRNOTAVAIL;
 }
 
 /* Send out a delayed ack, the caller does the policy checking

net/ipv6/tcp_ipv6.c

@@ -136,7 +136,7 @@ static int tcp_v6_get_port(struct sock *sk, unsigned short snum)
 				break;
 	}
 	if (tb != NULL && tb->owners != NULL) {
-		if (tb->fastreuse != 0 && sk->reuse != 0 && sk->state != TCP_LISTEN) {
+		if (tb->fastreuse > 0 && sk->reuse != 0 && sk->state != TCP_LISTEN) {
 			goto success;
 		} else {
 			struct ipv6_pinfo *np = inet6_sk(sk);
@@ -499,11 +499,21 @@ static int tcp_v6_check_established(struct sock *sk)
 	return -EADDRNOTAVAIL;
 }
 
-static int tcp_v6_hash_connecting(struct sock *sk)
+static int tcp_v6_hash_connect(struct sock *sk)
 {
-	unsigned short snum = inet_sk(sk)->num;
-	struct tcp_bind_hashbucket *head = &tcp_bhash[tcp_bhashfn(snum)];
-	struct tcp_bind_bucket *tb = head->chain;
+	struct tcp_bind_hashbucket *head;
+	struct tcp_bind_bucket *tb;
+
+	/* XXX */
+	if (inet_sk(sk)->num == 0) { 
+		int err = tcp_v6_get_port(sk, inet_sk(sk)->num);
+		if (err)
+			return err;
+		inet_sk(sk)->sport = htons(inet_sk(sk)->num);
+	}
+
+	head = &tcp_bhash[tcp_bhashfn(inet_sk(sk)->num)];
+	tb = head->chain;
 
 	spin_lock_bh(&head->lock);
 
@@ -534,7 +544,6 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 	struct in6_addr saddr_buf;
 	struct flowi fl;
 	struct dst_entry *dst;
-	struct sk_buff *buff;
 	int addr_type;
 	int err;
 
@@ -675,17 +684,12 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 		tp->ext_header_len = np->opt->opt_flen + np->opt->opt_nflen;
 	tp->mss_clamp = IPV6_MIN_MTU - sizeof(struct tcphdr) - sizeof(struct ipv6hdr);
 
-	err = -ENOBUFS;
-	buff = alloc_skb(MAX_TCP_HEADER + 15, sk->allocation);
-
-	if (buff == NULL)
-		goto failure;
-
 	inet->dport = usin->sin6_port;
 
-	/*
-	 *	Init variables
-	 */
+	tcp_set_state(sk, TCP_SYN_SENT);
+	err = tcp_v6_hash_connect(sk);
+	if (err)
+		goto late_failure;
 
 	if (!tp->write_seq)
 		tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
@@ -693,10 +697,14 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr,
 							     inet->sport,
 							     inet->dport);
 
-	err = tcp_connect(sk, buff);
-	if (err == 0)
+	err = tcp_connect(sk);
+	if (err)
+		goto late_failure;
+
 	return 0;
 
+late_failure:
+	tcp_set_state(sk, TCP_CLOSE);
 failure:
 	__sk_dst_reset(sk);
 	inet->dport = 0;
@@ -1785,7 +1793,6 @@ static struct tcp_func ipv6_specific = {
 	tcp_v6_rebuild_header,
 	tcp_v6_conn_request,
 	tcp_v6_syn_recv_sock,
-	tcp_v6_hash_connecting,
 	tcp_v6_remember_stamp,
 	sizeof(struct ipv6hdr),
 
@@ -1805,7 +1812,6 @@ static struct tcp_func ipv6_mapped = {
 	tcp_v4_rebuild_header,
 	tcp_v6_conn_request,
 	tcp_v6_syn_recv_sock,
-	tcp_v4_hash_connecting,
 	tcp_v4_remember_stamp,
 	sizeof(struct iphdr),
 

net/netsyms.c

@@ -364,7 +364,6 @@ EXPORT_SYMBOL(tcp_inherit_port);
 EXPORT_SYMBOL(tcp_v4_syn_recv_sock);
 EXPORT_SYMBOL(tcp_v4_do_rcv);
 EXPORT_SYMBOL(tcp_v4_connect);
-EXPORT_SYMBOL(tcp_v4_hash_connecting);
 EXPORT_SYMBOL(tcp_unhash);
 EXPORT_SYMBOL(udp_prot);
 EXPORT_SYMBOL(tcp_prot);