imported original firmware WRT54GL_v4.30.11_11_US

1 files changed, 2323 insertions, 0 deletions

diff --git a/release/src/linux/linux/net/ipv4/tcp_ipv4.c b/release/src/linux/linux/net/ipv4/tcp_ipv4.c
new file mode 100644
index 00000000..182e346b
--- /dev/null
+++ b/release/src/linux/linux/net/ipv4/tcp_ipv4.c
@@ -0,0 +1,2323 @@
+/*
+ * INET		An implementation of the TCP/IP protocol suite for the LINUX
+ *		operating system.  INET is implemented using the  BSD Socket
+ *		interface as the means of communication with the user level.
+ *
+ *		Implementation of the Transmission Control Protocol(TCP).
+ *
+ * Version:	$Id: tcp_ipv4.c,v 1.1.1.4 2003/10/14 08:09:33 sparq Exp $
+ *
+ *		IPv4 specific functions
+ *
+ *
+ *		code split from:
+ *		linux/ipv4/tcp.c
+ *		linux/ipv4/tcp_input.c
+ *		linux/ipv4/tcp_output.c
+ *
+ *		See tcp.c for author information
+ *
+ *	This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+
+/*
+ * Changes:
+ *		David S. Miller	:	New socket lookup architecture.
+ *					This code is dedicated to John Dyson.
+ *		David S. Miller :	Change semantics of established hash,
+ *					half is devoted to TIME_WAIT sockets
+ *					and the rest go in the other half.
+ *		Andi Kleen :		Add support for syncookies and fixed
+ *					some bugs: ip options weren't passed to
+ *					the TCP layer, missed a check for an ACK bit.
+ *		Andi Kleen :		Implemented fast path mtu discovery.
+ *	     				Fixed many serious bugs in the
+ *					open_request handling and moved
+ *					most of it into the af independent code.
+ *					Added tail drop and some other bugfixes.
+ *					Added new listen sematics.
+ *		Mike McLagan	:	Routing by source
+ *	Juan Jose Ciarlante:		ip_dynaddr bits
+ *		Andi Kleen:		various fixes.
+ *	Vitaly E. Lavrov	:	Transparent proxy revived after year coma.
+ *	Andi Kleen		:	Fix new listen.
+ *	Andi Kleen		:	Fix accept error reporting.
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/random.h>
+#include <linux/cache.h>
+#include <linux/init.h>
+
+#include <net/icmp.h>
+#include <net/tcp.h>
+#include <net/ipv6.h>
+#include <net/inet_common.h>
+
+#include <linux/inet.h>
+#include <linux/stddef.h>
+#include <linux/ipsec.h>
+
+extern int sysctl_ip_dynaddr;
+extern int sysctl_ip_default_ttl;
+int sysctl_tcp_tw_reuse = 0;
+
+/* Check TCP sequence numbers in ICMP packets. */
+#define ICMP_MIN_LENGTH 8
+
+/* Socket used for sending RSTs */ 	
+static struct inode tcp_inode;
+static struct socket *tcp_socket=&tcp_inode.u.socket_i;
+
+void tcp_v4_send_check(struct sock *sk, struct tcphdr *th, int len, 
+		       struct sk_buff *skb);
+
+/*
+ * ALL members must be initialised to prevent gcc-2.7.2.3 miscompilation
+ */
+struct tcp_hashinfo __cacheline_aligned tcp_hashinfo = {
+	__tcp_ehash:          NULL,
+	__tcp_bhash:          NULL,
+	__tcp_bhash_size:     0,
+	__tcp_ehash_size:     0,
+	__tcp_listening_hash: { NULL, },
+	__tcp_lhash_lock:     RW_LOCK_UNLOCKED,
+	__tcp_lhash_users:    ATOMIC_INIT(0),
+	__tcp_lhash_wait:
+	  __WAIT_QUEUE_HEAD_INITIALIZER(tcp_hashinfo.__tcp_lhash_wait),
+	__tcp_portalloc_lock: SPIN_LOCK_UNLOCKED
+};
+
+/*
+ * This array holds the first and last local port number.
+ * For high-usage systems, use sysctl to change this to
+ * 32768-61000
+ */
+int sysctl_local_port_range[2] = { 1024, 4999 };
+int tcp_port_rover = (1024 - 1);
+
+static __inline__ int tcp_hashfn(__u32 laddr, __u16 lport,
+				 __u32 faddr, __u16 fport)
+{
+	int h = ((laddr ^ lport) ^ (faddr ^ fport));
+	h ^= h>>16;
+	h ^= h>>8;
+	return h & (tcp_ehash_size - 1);
+}
+
+static __inline__ int tcp_sk_hashfn(struct sock *sk)
+{
+	__u32 laddr = sk->rcv_saddr;
+	__u16 lport = sk->num;
+	__u32 faddr = sk->daddr;
+	__u16 fport = sk->dport;
+
+	return tcp_hashfn(laddr, lport, faddr, fport);
+}
+
+/* Allocate and initialize a new TCP local port bind bucket.
+ * The bindhash mutex for snum's hash chain must be held here.
+ */
+struct tcp_bind_bucket *tcp_bucket_create(struct tcp_bind_hashbucket *head,
+					  unsigned short snum)
+{
+	struct tcp_bind_bucket *tb;
+
+	tb = kmem_cache_alloc(tcp_bucket_cachep, SLAB_ATOMIC);
+	if(tb != NULL) {
+		tb->port = snum;
+		tb->fastreuse = 0;
+		tb->owners = NULL;
+		if((tb->next = head->chain) != NULL)
+			tb->next->pprev = &tb->next;
+		head->chain = tb;
+		tb->pprev = &head->chain;
+	}
+	return tb;
+}
+
+/* Caller must disable local BH processing. */
+static __inline__ void __tcp_inherit_port(struct sock *sk, struct sock *child)
+{
+	struct tcp_bind_hashbucket *head = &tcp_bhash[tcp_bhashfn(child->num)];
+	struct tcp_bind_bucket *tb;
+
+	spin_lock(&head->lock);
+	tb = (struct tcp_bind_bucket *)sk->prev;
+	if ((child->bind_next = tb->owners) != NULL)
+		tb->owners->bind_pprev = &child->bind_next;
+	tb->owners = child;
+	child->bind_pprev = &tb->owners;
+	child->prev = (struct sock *) tb;
+	spin_unlock(&head->lock);
+}
+
+__inline__ void tcp_inherit_port(struct sock *sk, struct sock *child)
+{
+	local_bh_disable();
+	__tcp_inherit_port(sk, child);
+	local_bh_enable();
+}
+
+static inline void tcp_bind_hash(struct sock *sk, struct tcp_bind_bucket *tb, unsigned short snum)
+{
+	sk->num = snum;
+	if ((sk->bind_next = tb->owners) != NULL)
+		tb->owners->bind_pprev = &sk->bind_next;
+	tb->owners = sk;
+	sk->bind_pprev = &tb->owners;
+	sk->prev = (struct sock *) tb;
+}
+
+static inline int tcp_bind_conflict(struct sock *sk, struct tcp_bind_bucket *tb)
+{
+	struct sock *sk2 = tb->owners;
+	int sk_reuse = sk->reuse;
+	
+	for( ; sk2 != NULL; sk2 = sk2->bind_next) {
+		if (sk != sk2 &&
+		    sk2->reuse <= 1 &&
+		    sk->bound_dev_if == sk2->bound_dev_if) {
+			if (!sk_reuse	||
+			    !sk2->reuse	||
+			    sk2->state == TCP_LISTEN) {
+				if (!sk2->rcv_saddr	||
+				    !sk->rcv_saddr	||
+				    (sk2->rcv_saddr == sk->rcv_saddr))
+					break;
+			}
+		}
+	}
+	return sk2 != NULL;
+}
+
+/* Obtain a reference to a local port for the given sock,
+ * if snum is zero it means select any available local port.
+ */
+static int tcp_v4_get_port(struct sock *sk, unsigned short snum)
+{
+	struct tcp_bind_hashbucket *head;
+	struct tcp_bind_bucket *tb;
+	int ret;
+
+	local_bh_disable();
+	if (snum == 0) {
+		int low = sysctl_local_port_range[0];
+		int high = sysctl_local_port_range[1];
+		int remaining = (high - low) + 1;
+		int rover;
+
+		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);
+			for (tb = head->chain; tb; tb = tb->next)
+				if (tb->port == rover)
+					goto next;
+			break;
+		next:
+			spin_unlock(&head->lock);
+		} while (--remaining > 0);
+		tcp_port_rover = rover;
+		spin_unlock(&tcp_portalloc_lock);
+
+		/* Exhausted local port range during search? */
+		ret = 1;
+		if (remaining <= 0)
+			goto fail;
+
+		/* OK, here is the one we will use.  HEAD is
+		 * non-NULL and we hold it's mutex.
+		 */
+		snum = rover;
+		tb = NULL;
+	} else {
+		head = &tcp_bhash[tcp_bhashfn(snum)];
+		spin_lock(&head->lock);
+		for (tb = head->chain; tb != NULL; tb = tb->next)
+			if (tb->port == snum)
+				break;
+	}
+	if (tb != NULL && tb->owners != NULL) {
+		if (sk->reuse > 1)
+			goto success;
+		if (tb->fastreuse > 0 && sk->reuse != 0 && sk->state != TCP_LISTEN) {
+			goto success;
+		} else {
+			ret = 1;
+			if (tcp_bind_conflict(sk, tb))
+				goto fail_unlock;
+		}
+	}
+	ret = 1;
+	if (tb == NULL &&
+	    (tb = tcp_bucket_create(head, snum)) == NULL)
+			goto fail_unlock;
+	if (tb->owners == NULL) {
+		if (sk->reuse && sk->state != TCP_LISTEN)
+			tb->fastreuse = 1;
+		else
+			tb->fastreuse = 0;
+	} else if (tb->fastreuse &&
+		   ((sk->reuse == 0) || (sk->state == TCP_LISTEN)))
+		tb->fastreuse = 0;
+success:
+	if (sk->prev == NULL)
+		tcp_bind_hash(sk, tb, snum);
+	BUG_TRAP(sk->prev == (struct sock *) tb);
+ 	ret = 0;
+
+fail_unlock:
+	spin_unlock(&head->lock);
+fail:
+	local_bh_enable();
+	return ret;
+}
+
+/* Get rid of any references to a local port held by the
+ * given sock.
+ */
+__inline__ void __tcp_put_port(struct sock *sk)
+{
+	struct tcp_bind_hashbucket *head = &tcp_bhash[tcp_bhashfn(sk->num)];
+	struct tcp_bind_bucket *tb;
+
+	spin_lock(&head->lock);
+	tb = (struct tcp_bind_bucket *) sk->prev;
+	if (sk->bind_next)
+		sk->bind_next->bind_pprev = sk->bind_pprev;
+	*(sk->bind_pprev) = sk->bind_next;
+	sk->prev = NULL;
+	sk->num = 0;
+	if (tb->owners == NULL) {
+		if (tb->next)
+			tb->next->pprev = tb->pprev;
+		*(tb->pprev) = tb->next;
+		kmem_cache_free(tcp_bucket_cachep, tb);
+	}
+	spin_unlock(&head->lock);
+}
+
+void tcp_put_port(struct sock *sk)
+{
+	local_bh_disable();
+	__tcp_put_port(sk);
+	local_bh_enable();
+}
+
+/* This lock without WQ_FLAG_EXCLUSIVE is good on UP and it can be very bad on SMP.
+ * Look, when several writers sleep and reader wakes them up, all but one
+ * immediately hit write lock and grab all the cpus. Exclusive sleep solves
+ * this, _but_ remember, it adds useless work on UP machines (wake up each
+ * exclusive lock release). It should be ifdefed really.
+ */
+
+void tcp_listen_wlock(void)
+{
+	write_lock(&tcp_lhash_lock);
+
+	if (atomic_read(&tcp_lhash_users)) {
+		DECLARE_WAITQUEUE(wait, current);
+
+		add_wait_queue_exclusive(&tcp_lhash_wait, &wait);
+		for (;;) {
+			set_current_state(TASK_UNINTERRUPTIBLE);
+			if (atomic_read(&tcp_lhash_users) == 0)
+				break;
+			write_unlock_bh(&tcp_lhash_lock);
+			schedule();
+			write_lock_bh(&tcp_lhash_lock);
+		}
+
+		__set_current_state(TASK_RUNNING);
+		remove_wait_queue(&tcp_lhash_wait, &wait);
+	}
+}
+
+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(listen_possible && sk->state == TCP_LISTEN) {
+		skp = &tcp_listening_hash[tcp_sk_listen_hashfn(sk)];
+		lock = &tcp_lhash_lock;
+		tcp_listen_wlock();
+	} else {
+		skp = &tcp_ehash[(sk->hashent = tcp_sk_hashfn(sk))].chain;
+		lock = &tcp_ehash[sk->hashent].lock;
+		write_lock(lock);
+	}
+	if((sk->next = *skp) != NULL)
+		(*skp)->pprev = &sk->next;
+	*skp = sk;
+	sk->pprev = skp;
+	sock_prot_inc_use(sk->prot);
+	write_unlock(lock);
+	if (listen_possible && sk->state == TCP_LISTEN)
+		wake_up(&tcp_lhash_wait);
+}
+
+static void tcp_v4_hash(struct sock *sk)
+{
+	if (sk->state != TCP_CLOSE) {
+		local_bh_disable();
+		__tcp_v4_hash(sk, 1);
+		local_bh_enable();
+	}
+}
+
+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();
+		lock = &tcp_lhash_lock;
+	} else {
+		struct tcp_ehash_bucket *head = &tcp_ehash[sk->hashent];
+		lock = &head->lock;
+		write_lock_bh(&head->lock);
+	}
+
+	if(sk->pprev) {
+		if(sk->next)
+			sk->next->pprev = sk->pprev;
+		*sk->pprev = sk->next;
+		sk->pprev = NULL;
+		sock_prot_dec_use(sk->prot);
+	}
+	write_unlock_bh(lock);
+
+ ende:
+	if (sk->state == TCP_LISTEN)
+		wake_up(&tcp_lhash_wait);
+}
+
+/* Don't inline this cruft.  Here are some nice properties to
+ * exploit here.  The BSD API does not allow a listening TCP
+ * to specify the remote port nor the remote address for the
+ * connection.  So always assume those are both wildcarded
+ * during the search since they can never be otherwise.
+ */
+static struct sock *__tcp_v4_lookup_listener(struct sock *sk, u32 daddr, unsigned short hnum, int dif)
+{
+	struct sock *result = NULL;
+	int score, hiscore;
+
+	hiscore=0;
+	for(; sk; sk = sk->next) {
+		if(sk->num == hnum) {
+			__u32 rcv_saddr = sk->rcv_saddr;
+
+			score = 1;
+			if(rcv_saddr) {
+				if (rcv_saddr != daddr)
+					continue;
+				score++;
+			}
+			if (sk->bound_dev_if) {
+				if (sk->bound_dev_if != dif)
+					continue;
+				score++;
+			}
+			if (score == 3)
+				return sk;
+			if (score > hiscore) {
+				hiscore = score;
+				result = sk;
+			}
+		}
+	}
+	return result;
+}
+
+/* Optimize the common listener case. */
+__inline__ struct sock *tcp_v4_lookup_listener(u32 daddr, unsigned short hnum, int dif)
+{
+	struct sock *sk;
+
+	read_lock(&tcp_lhash_lock);
+	sk = tcp_listening_hash[tcp_lhashfn(hnum)];
+	if (sk) {
+		if (sk->num == hnum &&
+		    sk->next == NULL &&
+		    (!sk->rcv_saddr || sk->rcv_saddr == daddr) &&
+		    !sk->bound_dev_if)
+			goto sherry_cache;
+		sk = __tcp_v4_lookup_listener(sk, daddr, hnum, dif);
+	}
+	if (sk) {
+sherry_cache:
+		sock_hold(sk);
+	}
+	read_unlock(&tcp_lhash_lock);
+	return sk;
+}
+
+/* Sockets in TCP_CLOSE state are _always_ taken out of the hash, so
+ * we need not check it for TCP lookups anymore, thanks Alexey. -DaveM
+ *
+ * Local BH must be disabled here.
+ */
+
+static inline struct sock *__tcp_v4_lookup_established(u32 saddr, u16 sport,
+						       u32 daddr, u16 hnum, int dif)
+{
+	struct tcp_ehash_bucket *head;
+	TCP_V4_ADDR_COOKIE(acookie, saddr, daddr)
+	__u32 ports = TCP_COMBINED_PORTS(sport, hnum);
+	struct sock *sk;
+	int hash;
+
+	/* Optimize here for direct hit, only listening connections can
+	 * have wildcards anyways.
+	 */
+	hash = tcp_hashfn(daddr, hnum, saddr, sport);
+	head = &tcp_ehash[hash];
+	read_lock(&head->lock);
+	for(sk = head->chain; sk; sk = sk->next) {
+		if(TCP_IPV4_MATCH(sk, acookie, saddr, daddr, ports, dif))
+			goto hit; /* You sunk my battleship! */
+	}
+
+	/* Must check for a TIME_WAIT'er before going to listener hash. */
+	for(sk = (head + tcp_ehash_size)->chain; sk; sk = sk->next)
+		if(TCP_IPV4_MATCH(sk, acookie, saddr, daddr, ports, dif))
+			goto hit;
+	read_unlock(&head->lock);
+
+	return NULL;
+
+hit:
+	sock_hold(sk);
+	read_unlock(&head->lock);
+	return sk;
+}
+
+static inline struct sock *__tcp_v4_lookup(u32 saddr, u16 sport,
+					   u32 daddr, u16 hnum, int dif)
+{
+	struct sock *sk;
+
+	sk = __tcp_v4_lookup_established(saddr, sport, daddr, hnum, dif);
+
+	if (sk)
+		return sk;
+		
+	return tcp_v4_lookup_listener(daddr, hnum, dif);
+}
+
+__inline__ struct sock *tcp_v4_lookup(u32 saddr, u16 sport, u32 daddr, u16 dport, int dif)
+{
+	struct sock *sk;
+
+	local_bh_disable();
+	sk = __tcp_v4_lookup(saddr, sport, daddr, ntohs(dport), dif);
+	local_bh_enable();
+
+	return sk;
+}
+
+static inline __u32 tcp_v4_init_sequence(struct sock *sk, struct sk_buff *skb)
+{
+	return secure_tcp_sequence_number(skb->nh.iph->daddr,
+					  skb->nh.iph->saddr,
+					  skb->h.th->dest,
+					  skb->h.th->source);
+}
+
+/* called with local bh disabled */
+static int __tcp_v4_check_established(struct sock *sk, __u16 lport,
+				      struct tcp_tw_bucket **twp)
+{
+	u32 daddr = sk->rcv_saddr;
+	u32 saddr = sk->daddr;
+	int dif = sk->bound_dev_if;
+	TCP_V4_ADDR_COOKIE(acookie, saddr, daddr)
+	__u32 ports = TCP_COMBINED_PORTS(sk->dport, lport);
+	int hash = tcp_hashfn(daddr, lport, saddr, sk->dport);
+	struct tcp_ehash_bucket *head = &tcp_ehash[hash];
+	struct sock *sk2, **skp;
+	struct tcp_tw_bucket *tw;
+
+	write_lock(&head->lock);
+
+	/* Check TIME-WAIT sockets first. */
+	for(skp = &(head + tcp_ehash_size)->chain; (sk2=*skp) != NULL;
+	    skp = &sk2->next) {
+		tw = (struct tcp_tw_bucket*)sk2;
+
+		if(TCP_IPV4_MATCH(sk2, acookie, saddr, daddr, ports, dif)) {
+			struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
+
+			/* With PAWS, it is safe from the viewpoint
+			   of data integrity. Even without PAWS it
+			   is safe provided sequence spaces do not
+			   overlap i.e. at data rates <= 80Mbit/sec.
+
+			   Actually, the idea is close to VJ's one,
+			   only timestamp cache is held not per host,
+			   but per port pair and TW bucket is used
+			   as state holder.
+
+			   If TW bucket has been already destroyed we
+			   fall back to VJ's scheme and use initial
+			   timestamp retrieved from peer table.
+			 */
+			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;
+				tp->ts_recent = tw->ts_recent;
+				tp->ts_recent_stamp = tw->ts_recent_stamp;
+				sock_hold(sk2);
+				skp = &head->chain;
+				goto unique;
+			} else
+				goto not_unique;
+		}
+	}
+	tw = NULL;
+
+	/* And established part... */
+	for(skp = &head->chain; (sk2=*skp)!=NULL; skp = &sk2->next) {
+		if(TCP_IPV4_MATCH(sk2, acookie, saddr, daddr, ports, dif))
+			goto not_unique;
+	}
+
+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;
+
+	*skp = sk;
+	sk->pprev = skp;
+	sk->hashent = hash;
+	sock_prot_inc_use(sk->prot);
+	write_unlock(&head->lock);
+
+	if (twp) {
+		*twp = tw;
+		NET_INC_STATS_BH(TimeWaitRecycled);
+	} else if (tw) {
+		/* Silly. Should hash-dance instead... */
+		tcp_tw_deschedule(tw);
+		tcp_timewait_kill(tw);
+		NET_INC_STATS_BH(TimeWaitRecycled);
+
+		tcp_tw_put(tw);
+	}
+
+	return 0;
+
+not_unique:
+	write_unlock(&head->lock);
+	return -EADDRNOTAVAIL;
+}
+
+/*
+ * Bind a port for a connect operation and hash it.
+ */
+static int tcp_v4_hash_connect(struct sock *sk)
+{
+	unsigned short snum = sk->num;
+	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, 0);
+		spin_unlock_bh(&head->lock);
+		return 0;
+	} else {
+		int ret;
+		spin_unlock(&head->lock);
+		/* No definite answer... Walk to established hash table */
+		ret = __tcp_v4_check_established(sk, snum, NULL);
+		local_bh_enable();
+		return ret;
+	}
+}
+
+/* This will initiate an outgoing connection. */
+int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+	struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
+	struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
+	struct rtable *rt;
+	u32 daddr, nexthop;
+	int tmp;
+	int err;
+
+	if (addr_len < sizeof(struct sockaddr_in))
+		return(-EINVAL);
+
+	if (usin->sin_family != AF_INET)
+		return(-EAFNOSUPPORT);
+
+	nexthop = daddr = usin->sin_addr.s_addr;
+	if (sk->protinfo.af_inet.opt && sk->protinfo.af_inet.opt->srr) {
+		if (daddr == 0)
+			return -EINVAL;
+		nexthop = sk->protinfo.af_inet.opt->faddr;
+	}
+
+	tmp = ip_route_connect(&rt, nexthop, sk->saddr,
+			       RT_CONN_FLAGS(sk), sk->bound_dev_if);
+	if (tmp < 0)
+		return tmp;
+
+	if (rt->rt_flags&(RTCF_MULTICAST|RTCF_BROADCAST)) {
+		ip_rt_put(rt);
+		return -ENETUNREACH;
+	}
+
+	__sk_dst_set(sk, &rt->u.dst);
+	sk->route_caps = rt->u.dst.dev->features;
+
+	if (!sk->protinfo.af_inet.opt || !sk->protinfo.af_inet.opt->srr)
+		daddr = rt->rt_dst;
+
+	if (!sk->saddr)
+		sk->saddr = rt->rt_src;
+	sk->rcv_saddr = sk->saddr;
+
+	if (tp->ts_recent_stamp && sk->daddr != daddr) {
+		/* Reset inherited state */
+		tp->ts_recent = 0;
+		tp->ts_recent_stamp = 0;
+		tp->write_seq = 0;
+	}
+
+	if (sysctl_tcp_tw_recycle &&
+	    !tp->ts_recent_stamp &&
+	    rt->rt_dst == daddr) {
+		struct inet_peer *peer = rt_get_peer(rt);
+
+		/* VJ's idea. We save last timestamp seen from
+		 * the destination in peer table, when entering state TIME-WAIT
+		 * and initialize ts_recent from it, when trying new connection.
+		 */
+
+		if (peer && peer->tcp_ts_stamp + TCP_PAWS_MSL >= xtime.tv_sec) {
+			tp->ts_recent_stamp = peer->tcp_ts_stamp;
+			tp->ts_recent = peer->tcp_ts;
+		}
+	}
+
+	sk->dport = usin->sin_port;
+	sk->daddr = daddr;
+
+	tp->ext_header_len = 0;
+	if (sk->protinfo.af_inet.opt)
+		tp->ext_header_len = sk->protinfo.af_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(sk->saddr, sk->daddr,
+							   sk->sport, usin->sin_port);
+
+	sk->protinfo.af_inet.id = tp->write_seq^jiffies;
+
+	err = tcp_connect(sk);
+	if (err)
+		goto failure;
+
+	return 0;
+
+failure:
+	tcp_set_state(sk, TCP_CLOSE);
+	__sk_dst_reset(sk);
+	sk->route_caps = 0;
+	sk->dport = 0;
+	return err;
+}
+
+static __inline__ int tcp_v4_iif(struct sk_buff *skb)
+{
+	return ((struct rtable*)skb->dst)->rt_iif;
+}
+
+static __inline__ unsigned tcp_v4_synq_hash(u32 raddr, u16 rport)
+{
+	unsigned h = raddr ^ rport;
+	h ^= h>>16;
+	h ^= h>>8;
+	return h&(TCP_SYNQ_HSIZE-1);
+}
+
+static struct open_request *tcp_v4_search_req(struct tcp_opt *tp, 
+					      struct open_request ***prevp,
+					      __u16 rport,
+					      __u32 raddr, __u32 laddr)
+{
+	struct tcp_listen_opt *lopt = tp->listen_opt;
+	struct open_request *req, **prev;  
+
+	for (prev = &lopt->syn_table[tcp_v4_synq_hash(raddr, rport)];
+	     (req = *prev) != NULL;
+	     prev = &req->dl_next) {
+		if (req->rmt_port == rport &&
+		    req->af.v4_req.rmt_addr == raddr &&
+		    req->af.v4_req.loc_addr == laddr &&
+		    TCP_INET_FAMILY(req->class->family)) {
+			BUG_TRAP(req->sk == NULL);
+			*prevp = prev;
+			return req; 
+		}
+	}
+
+	return NULL;
+}
+
+static void tcp_v4_synq_add(struct sock *sk, struct open_request *req)
+{
+	struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
+	struct tcp_listen_opt *lopt = tp->listen_opt;
+	unsigned h = tcp_v4_synq_hash(req->af.v4_req.rmt_addr, req->rmt_port);
+
+	req->expires = jiffies + TCP_TIMEOUT_INIT;
+	req->retrans = 0;
+	req->sk = NULL;
+	req->dl_next = lopt->syn_table[h];
+
+	write_lock(&tp->syn_wait_lock);
+	lopt->syn_table[h] = req;
+	write_unlock(&tp->syn_wait_lock);
+
+	tcp_synq_added(sk);
+}
+
+
+/* 
+ * This routine does path mtu discovery as defined in RFC1191.
+ */
+static inline void do_pmtu_discovery(struct sock *sk, struct iphdr *ip, unsigned mtu)
+{
+	struct dst_entry *dst;
+	struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
+
+	/* We are not interested in TCP_LISTEN and open_requests (SYN-ACKs
+	 * send out by Linux are always <576bytes so they should go through
+	 * unfragmented).
+	 */
+	if (sk->state == TCP_LISTEN)
+		return; 
+
+	/* We don't check in the destentry if pmtu discovery is forbidden
+	 * on this route. We just assume that no packet_to_big packets
+	 * are send back when pmtu discovery is not active.
+     	 * There is a small race when the user changes this flag in the
+	 * route, but I think that's acceptable.
+	 */
+	if ((dst = __sk_dst_check(sk, 0)) == NULL)
+		return;
+
+	ip_rt_update_pmtu(dst, mtu);
+
+	/* Something is about to be wrong... Remember soft error
+	 * for the case, if this connection will not able to recover.
+	 */
+	if (mtu < dst->pmtu && ip_dont_fragment(sk, dst))
+		sk->err_soft = EMSGSIZE;
+
+	if (sk->protinfo.af_inet.pmtudisc != IP_PMTUDISC_DONT &&
+	    tp->pmtu_cookie > dst->pmtu) {
+		tcp_sync_mss(sk, dst->pmtu);
+
+		/* Resend the TCP packet because it's  
+		 * clear that the old packet has been
+		 * dropped. This is the new "fast" path mtu
+		 * discovery.
+		 */
+		tcp_simple_retransmit(sk);
+	} /* else let the usual retransmit timer handle it */
+}
+
+/*
+ * This routine is called by the ICMP module when it gets some
+ * sort of error condition.  If err < 0 then the socket should
+ * be closed and the error returned to the user.  If err > 0
+ * it's just the icmp type << 8 | icmp code.  After adjustment
+ * header points to the first 8 bytes of the tcp header.  We need
+ * to find the appropriate port.
+ *
+ * The locking strategy used here is very "optimistic". When
+ * someone else accesses the socket the ICMP is just dropped
+ * and for some paths there is no check at all.
+ * A more general error queue to queue errors for later handling
+ * is probably better.
+ *
+ */
+
+void tcp_v4_err(struct sk_buff *skb, u32 info)
+{
+	struct iphdr *iph = (struct iphdr*)skb->data;
+	struct tcphdr *th = (struct tcphdr*)(skb->data+(iph->ihl<<2));
+	struct tcp_opt *tp;
+	int type = skb->h.icmph->type;
+	int code = skb->h.icmph->code;
+	struct sock *sk;
+	__u32 seq;
+	int err;
+
+	if (skb->len < (iph->ihl << 2) + 8) {
+		ICMP_INC_STATS_BH(IcmpInErrors); 
+		return;
+	}
+
+	sk = tcp_v4_lookup(iph->daddr, th->dest, iph->saddr, th->source, tcp_v4_iif(skb));
+	if (sk == NULL) {
+		ICMP_INC_STATS_BH(IcmpInErrors);
+		return;
+	}
+	if (sk->state == TCP_TIME_WAIT) {
+		tcp_tw_put((struct tcp_tw_bucket*)sk);
+		return;
+	}
+
+	bh_lock_sock(sk);
+	/* If too many ICMPs get dropped on busy
+	 * servers this needs to be solved differently.
+	 */
+	if (sk->lock.users != 0)
+		NET_INC_STATS_BH(LockDroppedIcmps);
+
+	if (sk->state == TCP_CLOSE)
+		goto out;
+
+	tp = &sk->tp_pinfo.af_tcp;
+	seq = ntohl(th->seq);
+	if (sk->state != TCP_LISTEN && !between(seq, tp->snd_una, tp->snd_nxt)) {
+		NET_INC_STATS(OutOfWindowIcmps);
+		goto out;
+	}
+
+	switch (type) {
+	case ICMP_SOURCE_QUENCH:
+		/* This is deprecated, but if someone generated it,
+		 * we have no reasons to ignore it.
+		 */
+		if (sk->lock.users == 0)
+			tcp_enter_cwr(tp);
+		goto out;
+	case ICMP_PARAMETERPROB:
+		err = EPROTO;
+		break; 
+	case ICMP_DEST_UNREACH:
+		if (code > NR_ICMP_UNREACH)
+			goto out;
+
+		if (code == ICMP_FRAG_NEEDED) { /* PMTU discovery (RFC1191) */
+			if (sk->lock.users == 0)
+				do_pmtu_discovery(sk, iph, info);
+			goto out;
+		}
+
+		err = icmp_err_convert[code].errno;
+		break;
+	case ICMP_TIME_EXCEEDED:
+		err = EHOSTUNREACH;
+		break;
+	default:
+		goto out;
+	}
+
+	switch (sk->state) {
+		struct open_request *req, **prev;
+	case TCP_LISTEN:
+		if (sk->lock.users != 0)
+			goto out;
+
+		req = tcp_v4_search_req(tp, &prev,
+					th->dest,
+					iph->daddr, iph->saddr); 
+		if (!req)
+			goto out;
+
+		/* ICMPs are not backlogged, hence we cannot get
+		   an established socket here.
+		 */
+		BUG_TRAP(req->sk == NULL);
+
+		if (seq != req->snt_isn) {
+			NET_INC_STATS_BH(OutOfWindowIcmps);
+			goto out;
+		}
+
+		/* 
+		 * Still in SYN_RECV, just remove it silently.
+		 * There is no good way to pass the error to the newly
+		 * created socket, and POSIX does not want network
+		 * errors returned from accept(). 
+		 */ 
+		tcp_synq_drop(sk, req, prev);
+		goto out;
+
+	case TCP_SYN_SENT:
+	case TCP_SYN_RECV:  /* Cannot happen.
+			       It can f.e. if SYNs crossed.
+			     */ 
+		if (sk->lock.users == 0) {
+			TCP_INC_STATS_BH(TcpAttemptFails);
+			sk->err = err;
+
+			sk->error_report(sk);
+
+			tcp_done(sk);
+		} else {
+			sk->err_soft = err;
+		}
+		goto out;
+	}
+
+	/* If we've already connected we will keep trying
+	 * until we time out, or the user gives up.
+	 *
+	 * rfc1122 4.2.3.9 allows to consider as hard errors
+	 * only PROTO_UNREACH and PORT_UNREACH (well, FRAG_FAILED too,
+	 * but it is obsoleted by pmtu discovery).
+	 *
+	 * Note, that in modern internet, where routing is unreliable
+	 * and in each dark corner broken firewalls sit, sending random
+	 * errors ordered by their masters even this two messages finally lose
+	 * their original sense (even Linux sends invalid PORT_UNREACHs)
+	 *
+	 * Now we are in compliance with RFCs.
+	 *							--ANK (980905)
+	 */
+
+	if (sk->lock.users == 0 && sk->protinfo.af_inet.recverr) {
+		sk->err = err;
+		sk->error_report(sk);
+	} else	{ /* Only an error on timeout */
+		sk->err_soft = err;
+	}
+
+out:
+	bh_unlock_sock(sk);
+	sock_put(sk);
+}
+
+/* This routine computes an IPv4 TCP checksum. */
+void tcp_v4_send_check(struct sock *sk, struct tcphdr *th, int len, 
+		       struct sk_buff *skb)
+{
+	if (skb->ip_summed == CHECKSUM_HW) {
+		th->check = ~tcp_v4_check(th, len, sk->saddr, sk->daddr, 0);
+		skb->csum = offsetof(struct tcphdr, check);
+	} else {
+		th->check = tcp_v4_check(th, len, sk->saddr, sk->daddr,
+					 csum_partial((char *)th, th->doff<<2, skb->csum));
+	}
+}
+
+/*
+ *	This routine will send an RST to the other tcp.
+ *
+ *	Someone asks: why I NEVER use socket parameters (TOS, TTL etc.)
+ *		      for reset.
+ *	Answer: if a packet caused RST, it is not for a socket
+ *		existing in our system, if it is matched to a socket,
+ *		it is just duplicate segment or bug in other side's TCP.
+ *		So that we build reply only basing on parameters
+ *		arrived with segment.
+ *	Exception: precedence violation. We do not implement it in any case.
+ */
+
+static void tcp_v4_send_reset(struct sk_buff *skb)
+{
+	struct tcphdr *th = skb->h.th;
+	struct tcphdr rth;
+	struct ip_reply_arg arg;
+
+	/* Never send a reset in response to a reset. */
+	if (th->rst)
+		return;
+
+	if (((struct rtable*)skb->dst)->rt_type != RTN_LOCAL)
+		return;
+
+	/* Swap the send and the receive. */
+	memset(&rth, 0, sizeof(struct tcphdr)); 
+	rth.dest = th->source;
+	rth.source = th->dest; 
+	rth.doff = sizeof(struct tcphdr)/4;
+	rth.rst = 1;
+
+	if (th->ack) {
+		rth.seq = th->ack_seq;
+	} else {
+		rth.ack = 1;
+		rth.ack_seq = htonl(ntohl(th->seq) + th->syn + th->fin
+				    + skb->len - (th->doff<<2));
+	}
+
+	memset(&arg, 0, sizeof arg); 
+	arg.iov[0].iov_base = (unsigned char *)&rth; 
+	arg.iov[0].iov_len  = sizeof rth;
+	arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr, 
+				      skb->nh.iph->saddr, 
+				      sizeof(struct tcphdr),
+				      IPPROTO_TCP,
+				      0); 
+	arg.n_iov = 1;
+	arg.csumoffset = offsetof(struct tcphdr, check) / 2; 
+
+	tcp_socket->sk->protinfo.af_inet.ttl = sysctl_ip_default_ttl;
+	ip_send_reply(tcp_socket->sk, skb, &arg, sizeof rth);
+
+	TCP_INC_STATS_BH(TcpOutSegs);
+	TCP_INC_STATS_BH(TcpOutRsts);
+}
+
+/* The code following below sending ACKs in SYN-RECV and TIME-WAIT states
+   outside socket context is ugly, certainly. What can I do?
+ */
+
+static void tcp_v4_send_ack(struct sk_buff *skb, u32 seq, u32 ack, u32 win, u32 ts)
+{
+	struct tcphdr *th = skb->h.th;
+	struct {
+		struct tcphdr th;
+		u32 tsopt[3];
+	} rep;
+	struct ip_reply_arg arg;
+
+	memset(&rep.th, 0, sizeof(struct tcphdr));
+	memset(&arg, 0, sizeof arg);
+
+	arg.iov[0].iov_base = (unsigned char *)&rep; 
+	arg.iov[0].iov_len  = sizeof(rep.th);
+	arg.n_iov = 1;
+	if (ts) {
+		rep.tsopt[0] = htonl((TCPOPT_NOP << 24) |
+				     (TCPOPT_NOP << 16) |
+				     (TCPOPT_TIMESTAMP << 8) |
+				     TCPOLEN_TIMESTAMP);
+		rep.tsopt[1] = htonl(tcp_time_stamp);
+		rep.tsopt[2] = htonl(ts);
+		arg.iov[0].iov_len = sizeof(rep);
+	}
+
+	/* Swap the send and the receive. */
+	rep.th.dest = th->source;
+	rep.th.source = th->dest; 
+	rep.th.doff = arg.iov[0].iov_len/4;
+	rep.th.seq = htonl(seq);
+	rep.th.ack_seq = htonl(ack);
+	rep.th.ack = 1;
+	rep.th.window = htons(win);
+
+	arg.csum = csum_tcpudp_nofold(skb->nh.iph->daddr, 
+				      skb->nh.iph->saddr, 
+				      arg.iov[0].iov_len,
+				      IPPROTO_TCP,
+				      0);
+	arg.csumoffset = offsetof(struct tcphdr, check) / 2; 
+
+	ip_send_reply(tcp_socket->sk, skb, &arg, arg.iov[0].iov_len);
+
+	TCP_INC_STATS_BH(TcpOutSegs);
+}
+
+static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_tw_bucket *tw = (struct tcp_tw_bucket *)sk;
+
+	tcp_v4_send_ack(skb, tw->snd_nxt, tw->rcv_nxt,
+			tw->rcv_wnd>>tw->rcv_wscale, tw->ts_recent);
+
+	tcp_tw_put(tw);
+}
+
+static void tcp_v4_or_send_ack(struct sk_buff *skb, struct open_request *req)
+{
+	tcp_v4_send_ack(skb, req->snt_isn+1, req->rcv_isn+1, req->rcv_wnd,
+			req->ts_recent);
+}
+
+static struct dst_entry* tcp_v4_route_req(struct sock *sk, struct open_request *req)
+{
+	struct rtable *rt;
+	struct ip_options *opt;
+
+	opt = req->af.v4_req.opt;
+	if(ip_route_output(&rt, ((opt && opt->srr) ?
+				 opt->faddr :
+				 req->af.v4_req.rmt_addr),
+			   req->af.v4_req.loc_addr,
+			   RT_CONN_FLAGS(sk), sk->bound_dev_if)) {
+		IP_INC_STATS_BH(IpOutNoRoutes);
+		return NULL;
+	}
+	if (opt && opt->is_strictroute && rt->rt_dst != rt->rt_gateway) {
+		ip_rt_put(rt);
+		IP_INC_STATS_BH(IpOutNoRoutes);
+		return NULL;
+	}
+	return &rt->u.dst;
+}
+
+/*
+ *	Send a SYN-ACK after having received an ACK. 
+ *	This still operates on a open_request only, not on a big
+ *	socket.
+ */ 
+static int tcp_v4_send_synack(struct sock *sk, struct open_request *req,
+			      struct dst_entry *dst)
+{
+	int err = -1;
+	struct sk_buff * skb;
+
+	/* First, grab a route. */
+	if (dst == NULL &&
+	    (dst = tcp_v4_route_req(sk, req)) == NULL)
+		goto out;
+
+	skb = tcp_make_synack(sk, dst, req);
+
+	if (skb) {
+		struct tcphdr *th = skb->h.th;
+
+		th->check = tcp_v4_check(th, skb->len,
+					 req->af.v4_req.loc_addr, req->af.v4_req.rmt_addr,
+					 csum_partial((char *)th, skb->len, skb->csum));
+
+		err = ip_build_and_send_pkt(skb, sk, req->af.v4_req.loc_addr,
+					    req->af.v4_req.rmt_addr, req->af.v4_req.opt);
+		if (err == NET_XMIT_CN)
+			err = 0;
+	}
+
+out:
+	dst_release(dst);
+	return err;
+}
+
+/*
+ *	IPv4 open_request destructor.
+ */ 
+static void tcp_v4_or_free(struct open_request *req)
+{
+	if (req->af.v4_req.opt)
+		kfree(req->af.v4_req.opt);
+}
+
+static inline void syn_flood_warning(struct sk_buff *skb)
+{
+	static unsigned long warntime;
+	
+	if (jiffies - warntime > HZ*60) {
+		warntime = jiffies;
+		printk(KERN_INFO 
+		       "possible SYN flooding on port %d. Sending cookies.\n",  
+		       ntohs(skb->h.th->dest));
+	}
+}
+
+/* 
+ * Save and compile IPv4 options into the open_request if needed. 
+ */
+static inline struct ip_options * 
+tcp_v4_save_options(struct sock *sk, struct sk_buff *skb)
+{
+	struct ip_options *opt = &(IPCB(skb)->opt);
+	struct ip_options *dopt = NULL; 
+
+	if (opt && opt->optlen) {
+		int opt_size = optlength(opt); 
+		dopt = kmalloc(opt_size, GFP_ATOMIC);
+		if (dopt) {
+			if (ip_options_echo(dopt, skb)) {
+				kfree(dopt);
+				dopt = NULL;
+			}
+		}
+	}
+	return dopt;
+}
+
+/* 
+ * Maximum number of SYN_RECV sockets in queue per LISTEN socket.
+ * One SYN_RECV socket costs about 80bytes on a 32bit machine.
+ * It would be better to replace it with a global counter for all sockets
+ * but then some measure against one socket starving all other sockets
+ * would be needed.
+ *
+ * It was 128 by default. Experiments with real servers show, that
+ * it is absolutely not enough even at 100conn/sec. 256 cures most
+ * of problems. This value is adjusted to 128 for very small machines
+ * (<=32Mb of memory) and to 1024 on normal or better ones (>=256Mb).
+ * Further increasing requires to change hash table size.
+ */
+int sysctl_max_syn_backlog = 256; 
+
+struct or_calltable or_ipv4 = {
+	PF_INET,
+	tcp_v4_send_synack,
+	tcp_v4_or_send_ack,
+	tcp_v4_or_free,
+	tcp_v4_send_reset
+};
+
+int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb)
+{
+	struct tcp_opt tp;
+	struct open_request *req;
+	__u32 saddr = skb->nh.iph->saddr;
+	__u32 daddr = skb->nh.iph->daddr;
+	__u32 isn = TCP_SKB_CB(skb)->when;
+	struct dst_entry *dst = NULL;
+#ifdef CONFIG_SYN_COOKIES
+	int want_cookie = 0;
+#else
+#define want_cookie 0 /* Argh, why doesn't gcc optimize this :( */
+#endif
+
+	/* Never answer to SYNs send to broadcast or multicast */
+	if (((struct rtable *)skb->dst)->rt_flags & 
+	    (RTCF_BROADCAST|RTCF_MULTICAST))
+		goto drop; 
+
+	/* TW buckets are converted to open requests without
+	 * limitations, they conserve resources and peer is
+	 * evidently real one.
+	 */
+	if (tcp_synq_is_full(sk) && !isn) {
+#ifdef CONFIG_SYN_COOKIES
+		if (sysctl_tcp_syncookies) {
+			want_cookie = 1; 
+		} else
+#endif
+		goto drop;
+	}
+
+	/* Accept backlog is full. If we have already queued enough
+	 * of warm entries in syn queue, drop request. It is better than
+	 * clogging syn queue with openreqs with exponentially increasing
+	 * timeout.
+	 */
+	if (tcp_acceptq_is_full(sk) && tcp_synq_young(sk) > 1)
+		goto drop;
+
+	req = tcp_openreq_alloc();
+	if (req == NULL)
+		goto drop;
+
+	tcp_clear_options(&tp);
+	tp.mss_clamp = 536;
+	tp.user_mss = sk->tp_pinfo.af_tcp.user_mss;
+
+	tcp_parse_options(skb, &tp, 0);
+
+	if (want_cookie) {
+		tcp_clear_options(&tp);
+		tp.saw_tstamp = 0;
+	}
+
+	if (tp.saw_tstamp && tp.rcv_tsval == 0) {
+		/* Some OSes (unknown ones, but I see them on web server, which
+		 * contains information interesting only for windows'
+		 * users) do not send their stamp in SYN. It is easy case.
+		 * We simply do not advertise TS support.
+		 */
+		tp.saw_tstamp = 0;
+		tp.tstamp_ok = 0;
+	}
+	tp.tstamp_ok = tp.saw_tstamp;
+
+	tcp_openreq_init(req, &tp, skb);
+
+	req->af.v4_req.loc_addr = daddr;
+	req->af.v4_req.rmt_addr = saddr;
+	req->af.v4_req.opt = tcp_v4_save_options(sk, skb);
+	req->class = &or_ipv4;
+	if (!want_cookie)
+		TCP_ECN_create_request(req, skb->h.th);
+
+	if (want_cookie) {
+#ifdef CONFIG_SYN_COOKIES
+		syn_flood_warning(skb);
+#endif
+		isn = cookie_v4_init_sequence(sk, skb, &req->mss);
+	} else if (isn == 0) {
+		struct inet_peer *peer = NULL;
+
+		/* VJ's idea. We save last timestamp seen
+		 * from the destination in peer table, when entering
+		 * state TIME-WAIT, and check against it before
+		 * accepting new connection request.
+		 *
+		 * If "isn" is not zero, this request hit alive
+		 * timewait bucket, so that all the necessary checks
+		 * are made in the function processing timewait state.
+		 */
+		if (tp.saw_tstamp &&
+		    sysctl_tcp_tw_recycle &&
+		    (dst = tcp_v4_route_req(sk, req)) != NULL &&
+		    (peer = rt_get_peer((struct rtable*)dst)) != NULL &&
+		    peer->v4daddr == saddr) {
+			if (xtime.tv_sec < peer->tcp_ts_stamp + TCP_PAWS_MSL &&
+			    (s32)(peer->tcp_ts - req->ts_recent) > TCP_PAWS_WINDOW) {
+				NET_INC_STATS_BH(PAWSPassiveRejected);
+				dst_release(dst);
+				goto drop_and_free;
+			}
+		}
+		/* Kill the following clause, if you dislike this way. */
+		else if (!sysctl_tcp_syncookies &&
+			 (sysctl_max_syn_backlog - tcp_synq_len(sk)
+			  < (sysctl_max_syn_backlog>>2)) &&
+			 (!peer || !peer->tcp_ts_stamp) &&
+			 (!dst || !dst->rtt)) {
+			/* Without syncookies last quarter of
+			 * backlog is filled with destinations, proven to be alive.
+			 * It means that we continue to communicate
+			 * to destinations, already remembered
+			 * to the moment of synflood.
+			 */
+			NETDEBUG(if (net_ratelimit()) \
+				printk(KERN_DEBUG "TCP: drop open request from %u.%u.%u.%u/%u\n", \
+					NIPQUAD(saddr), ntohs(skb->h.th->source)));
+			dst_release(dst);
+			goto drop_and_free;
+		}
+
+		isn = tcp_v4_init_sequence(sk, skb);
+	}
+	req->snt_isn = isn;
+
+	if (tcp_v4_send_synack(sk, req, dst))
+		goto drop_and_free;
+
+	if (want_cookie) {
+	   	tcp_openreq_free(req); 
+	} else {
+		tcp_v4_synq_add(sk, req);
+	}
+	return 0;
+
+drop_and_free:
+	tcp_openreq_free(req); 
+drop:
+	TCP_INC_STATS_BH(TcpAttemptFails);
+	return 0;
+}
+
+
+/* 
+ * The three way handshake has completed - we got a valid synack - 
+ * now create the new socket. 
+ */
+struct sock * tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
+				   struct open_request *req,
+				   struct dst_entry *dst)
+{
+	struct tcp_opt *newtp;
+	struct sock *newsk;
+
+	if (tcp_acceptq_is_full(sk))
+		goto exit_overflow;
+
+	if (dst == NULL &&
+	    (dst = tcp_v4_route_req(sk, req)) == NULL)
+		goto exit;
+
+	newsk = tcp_create_openreq_child(sk, req, skb);
+	if (!newsk)
+		goto exit;
+
+	newsk->dst_cache = dst;
+	newsk->route_caps = dst->dev->features;
+
+	newtp = &(newsk->tp_pinfo.af_tcp);
+	newsk->daddr = req->af.v4_req.rmt_addr;
+	newsk->saddr = req->af.v4_req.loc_addr;
+	newsk->rcv_saddr = req->af.v4_req.loc_addr;
+	newsk->protinfo.af_inet.opt = req->af.v4_req.opt;
+	req->af.v4_req.opt = NULL;
+	newsk->protinfo.af_inet.mc_index = tcp_v4_iif(skb);
+	newsk->protinfo.af_inet.mc_ttl = skb->nh.iph->ttl;
+	newtp->ext_header_len = 0;
+	if (newsk->protinfo.af_inet.opt)
+		newtp->ext_header_len = newsk->protinfo.af_inet.opt->optlen;
+	newsk->protinfo.af_inet.id = newtp->write_seq^jiffies;
+
+	tcp_sync_mss(newsk, dst->pmtu);
+	newtp->advmss = dst->advmss;
+	tcp_initialize_rcv_mss(newsk);
+
+	__tcp_v4_hash(newsk, 0);
+	__tcp_inherit_port(sk, newsk);
+
+	return newsk;
+
+exit_overflow:
+	NET_INC_STATS_BH(ListenOverflows);
+exit:
+	NET_INC_STATS_BH(ListenDrops);
+	dst_release(dst);
+	return NULL;
+}
+
+static struct sock *tcp_v4_hnd_req(struct sock *sk,struct sk_buff *skb)
+{
+	struct open_request *req, **prev;
+	struct tcphdr *th = skb->h.th;
+	struct iphdr *iph = skb->nh.iph;
+	struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
+	struct sock *nsk;
+
+	/* Find possible connection requests. */
+	req = tcp_v4_search_req(tp, &prev,
+				th->source,
+				iph->saddr, iph->daddr);
+	if (req)
+		return tcp_check_req(sk, skb, req, prev);
+
+	nsk = __tcp_v4_lookup_established(skb->nh.iph->saddr,
+					  th->source,
+					  skb->nh.iph->daddr,
+					  ntohs(th->dest),
+					  tcp_v4_iif(skb));
+
+	if (nsk) {
+		if (nsk->state != TCP_TIME_WAIT) {
+			bh_lock_sock(nsk);
+			return nsk;
+		}
+		tcp_tw_put((struct tcp_tw_bucket*)nsk);
+		return NULL;
+	}
+
+#ifdef CONFIG_SYN_COOKIES
+	if (!th->rst && !th->syn && th->ack)
+		sk = cookie_v4_check(sk, skb, &(IPCB(skb)->opt));
+#endif
+	return sk;
+}
+
+static int tcp_v4_checksum_init(struct sk_buff *skb)
+{
+	if (skb->ip_summed == CHECKSUM_HW) {
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+		if (!tcp_v4_check(skb->h.th,skb->len,skb->nh.iph->saddr,
+				  skb->nh.iph->daddr,skb->csum))
+			return 0;
+
+		NETDEBUG(if (net_ratelimit()) printk(KERN_DEBUG "hw tcp v4 csum failed\n"));
+		skb->ip_summed = CHECKSUM_NONE;
+	}
+	if (skb->len <= 76) {
+		if (tcp_v4_check(skb->h.th,skb->len,skb->nh.iph->saddr,
+				 skb->nh.iph->daddr,
+				 skb_checksum(skb, 0, skb->len, 0)))
+			return -1;
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	} else {
+		skb->csum = ~tcp_v4_check(skb->h.th,skb->len,skb->nh.iph->saddr,
+					  skb->nh.iph->daddr,0);
+	}
+	return 0;
+}
+
+
+/* The socket must have it's spinlock held when we get
+ * here.
+ *
+ * We have a potential double-lock case here, so even when
+ * doing backlog processing we use the BH locking scheme.
+ * This is because we cannot sleep with the original spinlock
+ * held.
+ */
+int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
+{
+#ifdef CONFIG_FILTER
+	struct sk_filter *filter = sk->filter;
+	if (filter && sk_filter(skb, filter))
+		goto discard;
+#endif /* CONFIG_FILTER */
+
+  	IP_INC_STATS_BH(IpInDelivers);
+
+	if (sk->state == TCP_ESTABLISHED) { /* Fast path */
+		TCP_CHECK_TIMER(sk);
+		if (tcp_rcv_established(sk, skb, skb->h.th, skb->len))
+			goto reset;
+		TCP_CHECK_TIMER(sk);
+		return 0; 
+	}
+
+	if (skb->len < (skb->h.th->doff<<2) || tcp_checksum_complete(skb))
+		goto csum_err;
+
+	if (sk->state == TCP_LISTEN) { 
+		struct sock *nsk = tcp_v4_hnd_req(sk, skb);
+		if (!nsk)
+			goto discard;
+
+		if (nsk != sk) {
+			if (tcp_child_process(sk, nsk, skb))
+				goto reset;
+			return 0;
+		}
+	}
+
+	TCP_CHECK_TIMER(sk);
+	if (tcp_rcv_state_process(sk, skb, skb->h.th, skb->len))
+		goto reset;
+	TCP_CHECK_TIMER(sk);
+	return 0;
+
+reset:
+	tcp_v4_send_reset(skb);
+discard:
+	kfree_skb(skb);
+	/* Be careful here. If this function gets more complicated and
+	 * gcc suffers from register pressure on the x86, sk (in %ebx) 
+	 * might be destroyed here. This current version compiles correctly,
+	 * but you have been warned.
+	 */
+	return 0;
+
+csum_err:
+	TCP_INC_STATS_BH(TcpInErrs);
+	goto discard;
+}
+
+/*
+ *	From tcp_input.c
+ */
+
+int tcp_v4_rcv(struct sk_buff *skb)
+{
+	struct tcphdr *th;
+	struct sock *sk;
+	int ret;
+
+	if (skb->pkt_type!=PACKET_HOST)
+		goto discard_it;
+
+	/* Count it even if it's bad */
+	TCP_INC_STATS_BH(TcpInSegs);
+
+	if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
+		goto discard_it;
+
+	th = skb->h.th;
+
+	if (th->doff < sizeof(struct tcphdr)/4)
+		goto bad_packet;
+	if (!pskb_may_pull(skb, th->doff*4))
+		goto discard_it;
+
+	/* An explanation is required here, I think.
+	 * Packet length and doff are validated by header prediction,
+	 * provided case of th->doff==0 is elimineted.
+	 * So, we defer the checks. */
+	if ((skb->ip_summed != CHECKSUM_UNNECESSARY &&
+	     tcp_v4_checksum_init(skb) < 0))
+		goto bad_packet;
+
+	th = skb->h.th;
+	TCP_SKB_CB(skb)->seq = ntohl(th->seq);
+	TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
+				    skb->len - th->doff*4);
+	TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
+	TCP_SKB_CB(skb)->when = 0;
+	TCP_SKB_CB(skb)->flags = skb->nh.iph->tos;
+	TCP_SKB_CB(skb)->sacked = 0;
+
+	sk = __tcp_v4_lookup(skb->nh.iph->saddr, th->source,
+			     skb->nh.iph->daddr, ntohs(th->dest), tcp_v4_iif(skb));
+
+	if (!sk)
+		goto no_tcp_socket;
+
+process:
+	if(!ipsec_sk_policy(sk,skb))
+		goto discard_and_relse;
+
+	if (sk->state == TCP_TIME_WAIT)
+		goto do_time_wait;
+
+	skb->dev = NULL;
+
+	bh_lock_sock(sk);
+	ret = 0;
+	if (!sk->lock.users) {
+		if (!tcp_prequeue(sk, skb))
+			ret = tcp_v4_do_rcv(sk, skb);
+	} else
+		sk_add_backlog(sk, skb);
+	bh_unlock_sock(sk);
+
+	sock_put(sk);
+
+	return ret;
+
+no_tcp_socket:
+	if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
+bad_packet:
+		TCP_INC_STATS_BH(TcpInErrs);
+	} else {
+		tcp_v4_send_reset(skb);
+	}
+
+discard_it:
+	/* Discard frame. */
+	kfree_skb(skb);
+  	return 0;
+
+discard_and_relse:
+	sock_put(sk);
+	goto discard_it;
+
+do_time_wait:
+	if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
+		TCP_INC_STATS_BH(TcpInErrs);
+		goto discard_and_relse;
+	}
+	switch(tcp_timewait_state_process((struct tcp_tw_bucket *)sk,
+					  skb, th, skb->len)) {
+	case TCP_TW_SYN:
+	{
+		struct sock *sk2;
+
+		sk2 = tcp_v4_lookup_listener(skb->nh.iph->daddr, ntohs(th->dest), tcp_v4_iif(skb));
+		if (sk2 != NULL) {
+			tcp_tw_deschedule((struct tcp_tw_bucket *)sk);
+			tcp_timewait_kill((struct tcp_tw_bucket *)sk);
+			tcp_tw_put((struct tcp_tw_bucket *)sk);
+			sk = sk2;
+			goto process;
+		}
+		/* Fall through to ACK */
+	}
+	case TCP_TW_ACK:
+		tcp_v4_timewait_ack(sk, skb);
+		break;
+	case TCP_TW_RST:
+		goto no_tcp_socket;
+	case TCP_TW_SUCCESS:;
+	}
+	goto discard_it;
+}
+
+/* With per-bucket locks this operation is not-atomic, so that
+ * this version is not worse.
+ */
+static void __tcp_v4_rehash(struct sock *sk)
+{
+	sk->prot->unhash(sk);
+	sk->prot->hash(sk);
+}
+
+static int tcp_v4_reselect_saddr(struct sock *sk)
+{
+	int err;
+	struct rtable *rt;
+	__u32 old_saddr = sk->saddr;
+	__u32 new_saddr;
+	__u32 daddr = sk->daddr;
+
+	if(sk->protinfo.af_inet.opt && sk->protinfo.af_inet.opt->srr)
+		daddr = sk->protinfo.af_inet.opt->faddr;
+
+	/* Query new route. */
+	err = ip_route_connect(&rt, daddr, 0,
+			       RT_TOS(sk->protinfo.af_inet.tos)|sk->localroute,
+			       sk->bound_dev_if);
+	if (err)
+		return err;
+
+	__sk_dst_set(sk, &rt->u.dst);
+	sk->route_caps = rt->u.dst.dev->features;
+
+	new_saddr = rt->rt_src;
+
+	if (new_saddr == old_saddr)
+		return 0;
+
+	if (sysctl_ip_dynaddr > 1) {
+		printk(KERN_INFO "tcp_v4_rebuild_header(): shifting sk->saddr "
+		       "from %d.%d.%d.%d to %d.%d.%d.%d\n",
+		       NIPQUAD(old_saddr), 
+		       NIPQUAD(new_saddr));
+	}
+
+	sk->saddr = new_saddr;
+	sk->rcv_saddr = new_saddr;
+
+	__tcp_v4_rehash(sk);
+	return 0;
+}
+
+int tcp_v4_rebuild_header(struct sock *sk)
+{
+	struct rtable *rt = (struct rtable *)__sk_dst_check(sk, 0);
+	u32 daddr;
+	int err;
+
+	/* Route is OK, nothing to do. */
+	if (rt != NULL)
+		return 0;
+
+	/* Reroute. */
+	daddr = sk->daddr;
+	if(sk->protinfo.af_inet.opt && sk->protinfo.af_inet.opt->srr)
+		daddr = sk->protinfo.af_inet.opt->faddr;
+
+	err = ip_route_output(&rt, daddr, sk->saddr,
+			      RT_CONN_FLAGS(sk), sk->bound_dev_if);
+	if (!err) {
+		__sk_dst_set(sk, &rt->u.dst);
+		sk->route_caps = rt->u.dst.dev->features;
+		return 0;
+	}
+
+	/* Routing failed... */
+	sk->route_caps = 0;
+
+	if (!sysctl_ip_dynaddr ||
+	    sk->state != TCP_SYN_SENT ||
+	    (sk->userlocks & SOCK_BINDADDR_LOCK) ||
+	    (err = tcp_v4_reselect_saddr(sk)) != 0)
+		sk->err_soft=-err;
+
+	return err;
+}
+
+static void v4_addr2sockaddr(struct sock *sk, struct sockaddr * uaddr)
+{
+	struct sockaddr_in *sin = (struct sockaddr_in *) uaddr;
+
+	sin->sin_family		= AF_INET;
+	sin->sin_addr.s_addr	= sk->daddr;
+	sin->sin_port		= sk->dport;
+}
+
+/* VJ's idea. Save last timestamp seen from this destination
+ * and hold it at least for normal timewait interval to use for duplicate
+ * segment detection in subsequent connections, before they enter synchronized
+ * state.
+ */
+
+int tcp_v4_remember_stamp(struct sock *sk)
+{
+	struct tcp_opt *tp = &sk->tp_pinfo.af_tcp;
+	struct rtable *rt = (struct rtable*)__sk_dst_get(sk);
+	struct inet_peer *peer = NULL;
+	int release_it = 0;
+
+	if (rt == NULL || rt->rt_dst != sk->daddr) {
+		peer = inet_getpeer(sk->daddr, 1);
+		release_it = 1;
+	} else {
+		if (rt->peer == NULL)
+			rt_bind_peer(rt, 1);
+		peer = rt->peer;
+	}
+
+	if (peer) {
+		if ((s32)(peer->tcp_ts - tp->ts_recent) <= 0 ||
+		    (peer->tcp_ts_stamp + TCP_PAWS_MSL < xtime.tv_sec &&
+		     peer->tcp_ts_stamp <= tp->ts_recent_stamp)) {
+			peer->tcp_ts_stamp = tp->ts_recent_stamp;
+			peer->tcp_ts = tp->ts_recent;
+		}
+		if (release_it)
+			inet_putpeer(peer);
+		return 1;
+	}
+
+	return 0;
+}
+
+int tcp_v4_tw_remember_stamp(struct tcp_tw_bucket *tw)
+{
+	struct inet_peer *peer = NULL;
+
+	peer = inet_getpeer(tw->daddr, 1);
+
+	if (peer) {
+		if ((s32)(peer->tcp_ts - tw->ts_recent) <= 0 ||
+		    (peer->tcp_ts_stamp + TCP_PAWS_MSL < xtime.tv_sec &&
+		     peer->tcp_ts_stamp <= tw->ts_recent_stamp)) {
+			peer->tcp_ts_stamp = tw->ts_recent_stamp;
+			peer->tcp_ts = tw->ts_recent;
+		}
+		inet_putpeer(peer);
+		return 1;
+	}
+
+	return 0;
+}
+
+struct tcp_func ipv4_specific = {
+	ip_queue_xmit,
+	tcp_v4_send_check,
+	tcp_v4_rebuild_header,
+	tcp_v4_conn_request,
+	tcp_v4_syn_recv_sock,
+	tcp_v4_remember_stamp,
+	sizeof(struct iphdr),
+
+	ip_setsockopt,
+	ip_getsockopt,
+	v4_addr2sockaddr,
+	sizeof(struct sockaddr_in)
+};
+
+/* NOTE: A lot of things set to zero explicitly by call to
+ *       sk_alloc() so need not be done here.
+ */
+static int tcp_v4_init_sock(struct sock *sk)
+{
+	struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
+
+	skb_queue_head_init(&tp->out_of_order_queue);
+	tcp_init_xmit_timers(sk);
+	tcp_prequeue_init(tp);
+
+	tp->rto  = TCP_TIMEOUT_INIT;
+	tp->mdev = TCP_TIMEOUT_INIT;
+      
+	/* So many TCP implementations out there (incorrectly) count the
+	 * initial SYN frame in their delayed-ACK and congestion control
+	 * algorithms that we must have the following bandaid to talk
+	 * efficiently to them.  -DaveM
+	 */
+	tp->snd_cwnd = 2;
+
+	/* See draft-stevens-tcpca-spec-01 for discussion of the
+	 * initialization of these values.
+	 */
+	tp->snd_ssthresh = 0x7fffffff;	/* Infinity */
+	tp->snd_cwnd_clamp = ~0;
+	tp->mss_cache = 536;
+
+	tp->reordering = sysctl_tcp_reordering;
+
+	sk->state = TCP_CLOSE;
+
+	sk->write_space = tcp_write_space;
+	sk->use_write_queue = 1;
+
+	sk->tp_pinfo.af_tcp.af_specific = &ipv4_specific;
+
+	sk->sndbuf = sysctl_tcp_wmem[1];
+	sk->rcvbuf = sysctl_tcp_rmem[1];
+
+	atomic_inc(&tcp_sockets_allocated);
+
+	return 0;
+}
+
+static int tcp_v4_destroy_sock(struct sock *sk)
+{
+	struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
+
+	tcp_clear_xmit_timers(sk);
+
+	/* Cleanup up the write buffer. */
+  	tcp_writequeue_purge(sk);
+
+	/* Cleans up our, hopefully empty, out_of_order_queue. */
+  	__skb_queue_purge(&tp->out_of_order_queue);
+
+	/* Clean prequeue, it must be empty really */
+	__skb_queue_purge(&tp->ucopy.prequeue);
+
+	/* Clean up a referenced TCP bind bucket. */
+	if(sk->prev != NULL)
+		tcp_put_port(sk);
+
+	/* If sendmsg cached page exists, toss it. */
+	if (tp->sndmsg_page != NULL)
+		__free_page(tp->sndmsg_page);
+
+	atomic_dec(&tcp_sockets_allocated);
+
+	return 0;
+}
+
+/* Proc filesystem TCP sock list dumping. */
+static void get_openreq(struct sock *sk, struct open_request *req, char *tmpbuf, int i, int uid)
+{
+	int ttd = req->expires - jiffies;
+
+	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
+		" %02X %08X:%08X %02X:%08X %08X %5d %8d %u %d %p",
+		i,
+		req->af.v4_req.loc_addr,
+		ntohs(sk->sport),
+		req->af.v4_req.rmt_addr,
+		ntohs(req->rmt_port),
+		TCP_SYN_RECV,
+		0,0, /* could print option size, but that is af dependent. */
+		1,   /* timers active (only the expire timer) */  
+		ttd, 
+		req->retrans,
+		uid,
+		0,  /* non standard timer */  
+		0, /* open_requests have no inode */
+		atomic_read(&sk->refcnt),
+		req
+		); 
+}
+
+static void get_tcp_sock(struct sock *sp, char *tmpbuf, int i)
+{
+	unsigned int dest, src;
+	__u16 destp, srcp;
+	int timer_active;
+	unsigned long timer_expires;
+	struct tcp_opt *tp = &sp->tp_pinfo.af_tcp;
+
+	dest  = sp->daddr;
+	src   = sp->rcv_saddr;
+	destp = ntohs(sp->dport);
+	srcp  = ntohs(sp->sport);
+	if (tp->pending == TCP_TIME_RETRANS) {
+		timer_active	= 1;
+		timer_expires	= tp->timeout;
+	} else if (tp->pending == TCP_TIME_PROBE0) {
+		timer_active	= 4;
+		timer_expires	= tp->timeout;
+	} else if (timer_pending(&sp->timer)) {
+		timer_active	= 2;
+		timer_expires	= sp->timer.expires;
+	} else {
+		timer_active	= 0;
+		timer_expires = jiffies;
+	}
+
+	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
+		" %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p %u %u %u %u %d",
+		i, src, srcp, dest, destp, sp->state, 
+		tp->write_seq-tp->snd_una, tp->rcv_nxt-tp->copied_seq,
+		timer_active, timer_expires-jiffies,
+		tp->retransmits,
+		sock_i_uid(sp),
+		tp->probes_out,
+		sock_i_ino(sp),
+		atomic_read(&sp->refcnt), sp,
+		tp->rto, tp->ack.ato, (tp->ack.quick<<1)|tp->ack.pingpong,
+		tp->snd_cwnd, tp->snd_ssthresh>=0xFFFF?-1:tp->snd_ssthresh
+		);
+}
+
+static void get_timewait_sock(struct tcp_tw_bucket *tw, char *tmpbuf, int i)
+{
+	unsigned int dest, src;
+	__u16 destp, srcp;
+	int ttd = tw->ttd - jiffies;
+
+	if (ttd < 0)
+		ttd = 0;
+
+	dest  = tw->daddr;
+	src   = tw->rcv_saddr;
+	destp = ntohs(tw->dport);
+	srcp  = ntohs(tw->sport);
+
+	sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
+		" %02X %08X:%08X %02X:%08X %08X %5d %8d %d %d %p",
+		i, src, srcp, dest, destp, tw->substate, 0, 0,
+		3, ttd, 0, 0, 0, 0,
+		atomic_read(&tw->refcnt), tw);
+}
+
+#define TMPSZ 150
+
+int tcp_get_info(char *buffer, char **start, off_t offset, int length)
+{
+	int len = 0, num = 0, i;
+	off_t begin, pos = 0;
+	char tmpbuf[TMPSZ+1];
+
+	if (offset < TMPSZ)
+		len += sprintf(buffer, "%-*s\n", TMPSZ-1,
+			       "  sl  local_address rem_address   st tx_queue "
+			       "rx_queue tr tm->when retrnsmt   uid  timeout inode");
+
+	pos = TMPSZ;
+
+	/* First, walk listening socket table. */
+	tcp_listen_lock();
+	for(i = 0; i < TCP_LHTABLE_SIZE; i++) {
+		struct sock *sk;
+		struct tcp_listen_opt *lopt;
+		int k;
+
+		for (sk = tcp_listening_hash[i]; sk; sk = sk->next, num++) {
+			struct open_request *req;
+			int uid;
+			struct tcp_opt *tp = &(sk->tp_pinfo.af_tcp);
+
+			if (!TCP_INET_FAMILY(sk->family))
+				goto skip_listen;
+
+			pos += TMPSZ;
+			if (pos >= offset) {
+				get_tcp_sock(sk, tmpbuf, num);
+				len += sprintf(buffer+len, "%-*s\n", TMPSZ-1, tmpbuf);
+				if (pos >= offset + length) {
+					tcp_listen_unlock();
+					goto out_no_bh;
+				}
+			}
+
+skip_listen:
+			uid = sock_i_uid(sk);
+			read_lock_bh(&tp->syn_wait_lock);
+			lopt = tp->listen_opt;
+			if (lopt && lopt->qlen != 0) {
+				for (k=0; k<TCP_SYNQ_HSIZE; k++) {
+					for (req = lopt->syn_table[k]; req; req = req->dl_next, num++) {
+						if (!TCP_INET_FAMILY(req->class->family))
+							continue;
+
+						pos += TMPSZ;
+						if (pos <= offset)
+							continue;
+						get_openreq(sk, req, tmpbuf, num, uid);
+						len += sprintf(buffer+len, "%-*s\n", TMPSZ-1, tmpbuf);
+						if (pos >= offset + length) {
+							read_unlock_bh(&tp->syn_wait_lock);
+							tcp_listen_unlock();
+							goto out_no_bh;
+						}
+					}
+				}
+			}
+			read_unlock_bh(&tp->syn_wait_lock);
+
+			/* Completed requests are in normal socket hash table */
+		}
+	}
+	tcp_listen_unlock();
+
+	local_bh_disable();
+
+	/* Next, walk established hash chain. */
+	for (i = 0; i < tcp_ehash_size; i++) {
+		struct tcp_ehash_bucket *head = &tcp_ehash[i];
+		struct sock *sk;
+		struct tcp_tw_bucket *tw;
+
+		read_lock(&head->lock);
+		for(sk = head->chain; sk; sk = sk->next, num++) {
+			if (!TCP_INET_FAMILY(sk->family))
+				continue;
+			pos += TMPSZ;
+			if (pos <= offset)
+				continue;
+			get_tcp_sock(sk, tmpbuf, num);
+			len += sprintf(buffer+len, "%-*s\n", TMPSZ-1, tmpbuf);
+			if (pos >= offset + length) {
+				read_unlock(&head->lock);
+				goto out;
+			}
+		}
+		for (tw = (struct tcp_tw_bucket *)tcp_ehash[i+tcp_ehash_size].chain;
+		     tw != NULL;
+		     tw = (struct tcp_tw_bucket *)tw->next, num++) {
+			if (!TCP_INET_FAMILY(tw->family))
+				continue;
+			pos += TMPSZ;
+			if (pos <= offset)
+				continue;
+			get_timewait_sock(tw, tmpbuf, num);
+			len += sprintf(buffer+len, "%-*s\n", TMPSZ-1, tmpbuf);
+			if (pos >= offset + length) {
+				read_unlock(&head->lock);
+				goto out;
+			}
+		}
+		read_unlock(&head->lock);
+	}
+
+out:
+	local_bh_enable();
+out_no_bh:
+
+	begin = len - (pos - offset);
+	*start = buffer + begin;
+	len -= begin;
+	if (len > length)
+		len = length;
+	if (len < 0)
+		len = 0; 
+	return len;
+}
+
+struct proto tcp_prot = {
+	name:		"TCP",
+	close:		tcp_close,
+	connect:	tcp_v4_connect,
+	disconnect:	tcp_disconnect,
+	accept:		tcp_accept,
+	ioctl:		tcp_ioctl,
+	init:		tcp_v4_init_sock,
+	destroy:	tcp_v4_destroy_sock,
+	shutdown:	tcp_shutdown,
+	setsockopt:	tcp_setsockopt,
+	getsockopt:	tcp_getsockopt,
+	sendmsg:	tcp_sendmsg,
+	recvmsg:	tcp_recvmsg,
+	backlog_rcv:	tcp_v4_do_rcv,
+	hash:		tcp_v4_hash,
+	unhash:		tcp_unhash,
+	get_port:	tcp_v4_get_port,
+};
+
+
+
+void __init tcp_v4_init(struct net_proto_family *ops)
+{
+	int err;
+
+	tcp_inode.i_mode = S_IFSOCK;
+	tcp_inode.i_sock = 1;
+	tcp_inode.i_uid = 0;
+	tcp_inode.i_gid = 0;
+	init_waitqueue_head(&tcp_inode.i_wait);
+	init_waitqueue_head(&tcp_inode.u.socket_i.wait);
+
+	tcp_socket->inode = &tcp_inode;
+	tcp_socket->state = SS_UNCONNECTED;
+	tcp_socket->type=SOCK_RAW;
+
+	if ((err=ops->create(tcp_socket, IPPROTO_TCP))<0)
+		panic("Failed to create the TCP control socket.\n");
+	tcp_socket->sk->allocation=GFP_ATOMIC;
+	tcp_socket->sk->protinfo.af_inet.ttl = MAXTTL;
+
+	/* Unhash it so that IP input processing does not even
+	 * see it, we do not wish this socket to see incoming
+	 * packets.
+	 */
+	tcp_socket->sk->prot->unhash(tcp_socket->sk);
+}