Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 2386 insertions, 0 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
new file mode 100644
index 000000000000..5cff56af7855
--- /dev/null
+++ b/net/ipv4/tcp.c
@@ -0,0 +1,2386 @@
+/*
+ * 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.c,v 1.216 2002/02/01 22:01:04 davem Exp $
+ *
+ * Authors:	Ross Biro, <bir7@leland.Stanford.Edu>
+ *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *		Mark Evans, <evansmp@uhura.aston.ac.uk>
+ *		Corey Minyard <wf-rch!minyard@relay.EU.net>
+ *		Florian La Roche, <flla@stud.uni-sb.de>
+ *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
+ *		Linus Torvalds, <torvalds@cs.helsinki.fi>
+ *		Alan Cox, <gw4pts@gw4pts.ampr.org>
+ *		Matthew Dillon, <dillon@apollo.west.oic.com>
+ *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
+ *		Jorge Cwik, <jorge@laser.satlink.net>
+ *
+ * Fixes:
+ *		Alan Cox	:	Numerous verify_area() calls
+ *		Alan Cox	:	Set the ACK bit on a reset
+ *		Alan Cox	:	Stopped it crashing if it closed while
+ *					sk->inuse=1 and was trying to connect
+ *					(tcp_err()).
+ *		Alan Cox	:	All icmp error handling was broken
+ *					pointers passed where wrong and the
+ *					socket was looked up backwards. Nobody
+ *					tested any icmp error code obviously.
+ *		Alan Cox	:	tcp_err() now handled properly. It
+ *					wakes people on errors. poll
+ *					behaves and the icmp error race
+ *					has gone by moving it into sock.c
+ *		Alan Cox	:	tcp_send_reset() fixed to work for
+ *					everything not just packets for
+ *					unknown sockets.
+ *		Alan Cox	:	tcp option processing.
+ *		Alan Cox	:	Reset tweaked (still not 100%) [Had
+ *					syn rule wrong]
+ *		Herp Rosmanith  :	More reset fixes
+ *		Alan Cox	:	No longer acks invalid rst frames.
+ *					Acking any kind of RST is right out.
+ *		Alan Cox	:	Sets an ignore me flag on an rst
+ *					receive otherwise odd bits of prattle
+ *					escape still
+ *		Alan Cox	:	Fixed another acking RST frame bug.
+ *					Should stop LAN workplace lockups.
+ *		Alan Cox	: 	Some tidyups using the new skb list
+ *					facilities
+ *		Alan Cox	:	sk->keepopen now seems to work
+ *		Alan Cox	:	Pulls options out correctly on accepts
+ *		Alan Cox	:	Fixed assorted sk->rqueue->next errors
+ *		Alan Cox	:	PSH doesn't end a TCP read. Switched a
+ *					bit to skb ops.
+ *		Alan Cox	:	Tidied tcp_data to avoid a potential
+ *					nasty.
+ *		Alan Cox	:	Added some better commenting, as the
+ *					tcp is hard to follow
+ *		Alan Cox	:	Removed incorrect check for 20 * psh
+ *	Michael O'Reilly	:	ack < copied bug fix.
+ *	Johannes Stille		:	Misc tcp fixes (not all in yet).
+ *		Alan Cox	:	FIN with no memory -> CRASH
+ *		Alan Cox	:	Added socket option proto entries.
+ *					Also added awareness of them to accept.
+ *		Alan Cox	:	Added TCP options (SOL_TCP)
+ *		Alan Cox	:	Switched wakeup calls to callbacks,
+ *					so the kernel can layer network
+ *					sockets.
+ *		Alan Cox	:	Use ip_tos/ip_ttl settings.
+ *		Alan Cox	:	Handle FIN (more) properly (we hope).
+ *		Alan Cox	:	RST frames sent on unsynchronised
+ *					state ack error.
+ *		Alan Cox	:	Put in missing check for SYN bit.
+ *		Alan Cox	:	Added tcp_select_window() aka NET2E
+ *					window non shrink trick.
+ *		Alan Cox	:	Added a couple of small NET2E timer
+ *					fixes
+ *		Charles Hedrick :	TCP fixes
+ *		Toomas Tamm	:	TCP window fixes
+ *		Alan Cox	:	Small URG fix to rlogin ^C ack fight
+ *		Charles Hedrick	:	Rewrote most of it to actually work
+ *		Linus		:	Rewrote tcp_read() and URG handling
+ *					completely
+ *		Gerhard Koerting:	Fixed some missing timer handling
+ *		Matthew Dillon  :	Reworked TCP machine states as per RFC
+ *		Gerhard Koerting:	PC/TCP workarounds
+ *		Adam Caldwell	:	Assorted timer/timing errors
+ *		Matthew Dillon	:	Fixed another RST bug
+ *		Alan Cox	:	Move to kernel side addressing changes.
+ *		Alan Cox	:	Beginning work on TCP fastpathing
+ *					(not yet usable)
+ *		Arnt Gulbrandsen:	Turbocharged tcp_check() routine.
+ *		Alan Cox	:	TCP fast path debugging
+ *		Alan Cox	:	Window clamping
+ *		Michael Riepe	:	Bug in tcp_check()
+ *		Matt Dillon	:	More TCP improvements and RST bug fixes
+ *		Matt Dillon	:	Yet more small nasties remove from the
+ *					TCP code (Be very nice to this man if
+ *					tcp finally works 100%) 8)
+ *		Alan Cox	:	BSD accept semantics.
+ *		Alan Cox	:	Reset on closedown bug.
+ *	Peter De Schrijver	:	ENOTCONN check missing in tcp_sendto().
+ *		Michael Pall	:	Handle poll() after URG properly in
+ *					all cases.
+ *		Michael Pall	:	Undo the last fix in tcp_read_urg()
+ *					(multi URG PUSH broke rlogin).
+ *		Michael Pall	:	Fix the multi URG PUSH problem in
+ *					tcp_readable(), poll() after URG
+ *					works now.
+ *		Michael Pall	:	recv(...,MSG_OOB) never blocks in the
+ *					BSD api.
+ *		Alan Cox	:	Changed the semantics of sk->socket to
+ *					fix a race and a signal problem with
+ *					accept() and async I/O.
+ *		Alan Cox	:	Relaxed the rules on tcp_sendto().
+ *		Yury Shevchuk	:	Really fixed accept() blocking problem.
+ *		Craig I. Hagan  :	Allow for BSD compatible TIME_WAIT for
+ *					clients/servers which listen in on
+ *					fixed ports.
+ *		Alan Cox	:	Cleaned the above up and shrank it to
+ *					a sensible code size.
+ *		Alan Cox	:	Self connect lockup fix.
+ *		Alan Cox	:	No connect to multicast.
+ *		Ross Biro	:	Close unaccepted children on master
+ *					socket close.
+ *		Alan Cox	:	Reset tracing code.
+ *		Alan Cox	:	Spurious resets on shutdown.
+ *		Alan Cox	:	Giant 15 minute/60 second timer error
+ *		Alan Cox	:	Small whoops in polling before an
+ *					accept.
+ *		Alan Cox	:	Kept the state trace facility since
+ *					it's handy for debugging.
+ *		Alan Cox	:	More reset handler fixes.
+ *		Alan Cox	:	Started rewriting the code based on
+ *					the RFC's for other useful protocol
+ *					references see: Comer, KA9Q NOS, and
+ *					for a reference on the difference
+ *					between specifications and how BSD
+ *					works see the 4.4lite source.
+ *		A.N.Kuznetsov	:	Don't time wait on completion of tidy
+ *					close.
+ *		Linus Torvalds	:	Fin/Shutdown & copied_seq changes.
+ *		Linus Torvalds	:	Fixed BSD port reuse to work first syn
+ *		Alan Cox	:	Reimplemented timers as per the RFC
+ *					and using multiple timers for sanity.
+ *		Alan Cox	:	Small bug fixes, and a lot of new
+ *					comments.
+ *		Alan Cox	:	Fixed dual reader crash by locking
+ *					the buffers (much like datagram.c)
+ *		Alan Cox	:	Fixed stuck sockets in probe. A probe
+ *					now gets fed up of retrying without
+ *					(even a no space) answer.
+ *		Alan Cox	:	Extracted closing code better
+ *		Alan Cox	:	Fixed the closing state machine to
+ *					resemble the RFC.
+ *		Alan Cox	:	More 'per spec' fixes.
+ *		Jorge Cwik	:	Even faster checksumming.
+ *		Alan Cox	:	tcp_data() doesn't ack illegal PSH
+ *					only frames. At least one pc tcp stack
+ *					generates them.
+ *		Alan Cox	:	Cache last socket.
+ *		Alan Cox	:	Per route irtt.
+ *		Matt Day	:	poll()->select() match BSD precisely on error
+ *		Alan Cox	:	New buffers
+ *		Marc Tamsky	:	Various sk->prot->retransmits and
+ *					sk->retransmits misupdating fixed.
+ *					Fixed tcp_write_timeout: stuck close,
+ *					and TCP syn retries gets used now.
+ *		Mark Yarvis	:	In tcp_read_wakeup(), don't send an
+ *					ack if state is TCP_CLOSED.
+ *		Alan Cox	:	Look up device on a retransmit - routes may
+ *					change. Doesn't yet cope with MSS shrink right
+ *					but it's a start!
+ *		Marc Tamsky	:	Closing in closing fixes.
+ *		Mike Shaver	:	RFC1122 verifications.
+ *		Alan Cox	:	rcv_saddr errors.
+ *		Alan Cox	:	Block double connect().
+ *		Alan Cox	:	Small hooks for enSKIP.
+ *		Alexey Kuznetsov:	Path MTU discovery.
+ *		Alan Cox	:	Support soft errors.
+ *		Alan Cox	:	Fix MTU discovery pathological case
+ *					when the remote claims no mtu!
+ *		Marc Tamsky	:	TCP_CLOSE fix.
+ *		Colin (G3TNE)	:	Send a reset on syn ack replies in
+ *					window but wrong (fixes NT lpd problems)
+ *		Pedro Roque	:	Better TCP window handling, delayed ack.
+ *		Joerg Reuter	:	No modification of locked buffers in
+ *					tcp_do_retransmit()
+ *		Eric Schenk	:	Changed receiver side silly window
+ *					avoidance algorithm to BSD style
+ *					algorithm. This doubles throughput
+ *					against machines running Solaris,
+ *					and seems to result in general
+ *					improvement.
+ *	Stefan Magdalinski	:	adjusted tcp_readable() to fix FIONREAD
+ *	Willy Konynenberg	:	Transparent proxying support.
+ *	Mike McLagan		:	Routing by source
+ *		Keith Owens	:	Do proper merging with partial SKB's in
+ *					tcp_do_sendmsg to avoid burstiness.
+ *		Eric Schenk	:	Fix fast close down bug with
+ *					shutdown() followed by close().
+ *		Andi Kleen 	:	Make poll agree with SIGIO
+ *	Salvatore Sanfilippo	:	Support SO_LINGER with linger == 1 and
+ *					lingertime == 0 (RFC 793 ABORT Call)
+ *	Hirokazu Takahashi	:	Use copy_from_user() instead of
+ *					csum_and_copy_from_user() if possible.
+ *
+ *		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.
+ *
+ * Description of States:
+ *
+ *	TCP_SYN_SENT		sent a connection request, waiting for ack
+ *
+ *	TCP_SYN_RECV		received a connection request, sent ack,
+ *				waiting for final ack in three-way handshake.
+ *
+ *	TCP_ESTABLISHED		connection established
+ *
+ *	TCP_FIN_WAIT1		our side has shutdown, waiting to complete
+ *				transmission of remaining buffered data
+ *
+ *	TCP_FIN_WAIT2		all buffered data sent, waiting for remote
+ *				to shutdown
+ *
+ *	TCP_CLOSING		both sides have shutdown but we still have
+ *				data we have to finish sending
+ *
+ *	TCP_TIME_WAIT		timeout to catch resent junk before entering
+ *				closed, can only be entered from FIN_WAIT2
+ *				or CLOSING.  Required because the other end
+ *				may not have gotten our last ACK causing it
+ *				to retransmit the data packet (which we ignore)
+ *
+ *	TCP_CLOSE_WAIT		remote side has shutdown and is waiting for
+ *				us to finish writing our data and to shutdown
+ *				(we have to close() to move on to LAST_ACK)
+ *
+ *	TCP_LAST_ACK		out side has shutdown after remote has
+ *				shutdown.  There may still be data in our
+ *				buffer that we have to finish sending
+ *
+ *	TCP_CLOSE		socket is finished
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/smp_lock.h>
+#include <linux/fs.h>
+#include <linux/random.h>
+#include <linux/bootmem.h>
+
+#include <net/icmp.h>
+#include <net/tcp.h>
+#include <net/xfrm.h>
+#include <net/ip.h>
+
+
+#include <asm/uaccess.h>
+#include <asm/ioctls.h>
+
+int sysctl_tcp_fin_timeout = TCP_FIN_TIMEOUT;
+
+DEFINE_SNMP_STAT(struct tcp_mib, tcp_statistics);
+
+kmem_cache_t *tcp_openreq_cachep;
+kmem_cache_t *tcp_bucket_cachep;
+kmem_cache_t *tcp_timewait_cachep;
+
+atomic_t tcp_orphan_count = ATOMIC_INIT(0);
+
+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 };
+
+EXPORT_SYMBOL(sysctl_tcp_mem);
+EXPORT_SYMBOL(sysctl_tcp_rmem);
+EXPORT_SYMBOL(sysctl_tcp_wmem);
+
+atomic_t tcp_memory_allocated;	/* Current allocated memory. */
+atomic_t tcp_sockets_allocated;	/* Current number of TCP sockets. */
+
+EXPORT_SYMBOL(tcp_memory_allocated);
+EXPORT_SYMBOL(tcp_sockets_allocated);
+
+/*
+ * Pressure flag: try to collapse.
+ * Technical note: it is used by multiple contexts non atomically.
+ * All the sk_stream_mem_schedule() is of this nature: accounting
+ * is strict, actions are advisory and have some latency.
+ */
+int tcp_memory_pressure;
+
+EXPORT_SYMBOL(tcp_memory_pressure);
+
+void tcp_enter_memory_pressure(void)
+{
+	if (!tcp_memory_pressure) {
+		NET_INC_STATS(LINUX_MIB_TCPMEMORYPRESSURES);
+		tcp_memory_pressure = 1;
+	}
+}
+
+EXPORT_SYMBOL(tcp_enter_memory_pressure);
+
+/*
+ * LISTEN is a special case for poll..
+ */
+static __inline__ unsigned int tcp_listen_poll(struct sock *sk,
+					       poll_table *wait)
+{
+	return tcp_sk(sk)->accept_queue ? (POLLIN | POLLRDNORM) : 0;
+}
+
+/*
+ *	Wait for a TCP event.
+ *
+ *	Note that we don't need to lock the socket, as the upper poll layers
+ *	take care of normal races (between the test and the event) and we don't
+ *	go look at any of the socket buffers directly.
+ */
+unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
+{
+	unsigned int mask;
+	struct sock *sk = sock->sk;
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	poll_wait(file, sk->sk_sleep, wait);
+	if (sk->sk_state == TCP_LISTEN)
+		return tcp_listen_poll(sk, wait);
+
+	/* Socket is not locked. We are protected from async events
+	   by poll logic and correct handling of state changes
+	   made by another threads is impossible in any case.
+	 */
+
+	mask = 0;
+	if (sk->sk_err)
+		mask = POLLERR;
+
+	/*
+	 * POLLHUP is certainly not done right. But poll() doesn't
+	 * have a notion of HUP in just one direction, and for a
+	 * socket the read side is more interesting.
+	 *
+	 * Some poll() documentation says that POLLHUP is incompatible
+	 * with the POLLOUT/POLLWR flags, so somebody should check this
+	 * all. But careful, it tends to be safer to return too many
+	 * bits than too few, and you can easily break real applications
+	 * if you don't tell them that something has hung up!
+	 *
+	 * Check-me.
+	 *
+	 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
+	 * our fs/select.c). It means that after we received EOF,
+	 * poll always returns immediately, making impossible poll() on write()
+	 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
+	 * if and only if shutdown has been made in both directions.
+	 * Actually, it is interesting to look how Solaris and DUX
+	 * solve this dilemma. I would prefer, if PULLHUP were maskable,
+	 * then we could set it on SND_SHUTDOWN. BTW examples given
+	 * in Stevens' books assume exactly this behaviour, it explains
+	 * why PULLHUP is incompatible with POLLOUT.	--ANK
+	 *
+	 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
+	 * blocking on fresh not-connected or disconnected socket. --ANK
+	 */
+	if (sk->sk_shutdown == SHUTDOWN_MASK || sk->sk_state == TCP_CLOSE)
+		mask |= POLLHUP;
+	if (sk->sk_shutdown & RCV_SHUTDOWN)
+		mask |= POLLIN | POLLRDNORM;
+
+	/* Connected? */
+	if ((1 << sk->sk_state) & ~(TCPF_SYN_SENT | TCPF_SYN_RECV)) {
+		/* Potential race condition. If read of tp below will
+		 * escape above sk->sk_state, we can be illegally awaken
+		 * in SYN_* states. */
+		if ((tp->rcv_nxt != tp->copied_seq) &&
+		    (tp->urg_seq != tp->copied_seq ||
+		     tp->rcv_nxt != tp->copied_seq + 1 ||
+		     sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data))
+			mask |= POLLIN | POLLRDNORM;
+
+		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
+			if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
+				mask |= POLLOUT | POLLWRNORM;
+			} else {  /* send SIGIO later */
+				set_bit(SOCK_ASYNC_NOSPACE,
+					&sk->sk_socket->flags);
+				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+
+				/* Race breaker. If space is freed after
+				 * wspace test but before the flags are set,
+				 * IO signal will be lost.
+				 */
+				if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
+					mask |= POLLOUT | POLLWRNORM;
+			}
+		}
+
+		if (tp->urg_data & TCP_URG_VALID)
+			mask |= POLLPRI;
+	}
+	return mask;
+}
+
+int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int answ;
+
+	switch (cmd) {
+	case SIOCINQ:
+		if (sk->sk_state == TCP_LISTEN)
+			return -EINVAL;
+
+		lock_sock(sk);
+		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
+			answ = 0;
+		else if (sock_flag(sk, SOCK_URGINLINE) ||
+			 !tp->urg_data ||
+			 before(tp->urg_seq, tp->copied_seq) ||
+			 !before(tp->urg_seq, tp->rcv_nxt)) {
+			answ = tp->rcv_nxt - tp->copied_seq;
+
+			/* Subtract 1, if FIN is in queue. */
+			if (answ && !skb_queue_empty(&sk->sk_receive_queue))
+				answ -=
+		       ((struct sk_buff *)sk->sk_receive_queue.prev)->h.th->fin;
+		} else
+			answ = tp->urg_seq - tp->copied_seq;
+		release_sock(sk);
+		break;
+	case SIOCATMARK:
+		answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
+		break;
+	case SIOCOUTQ:
+		if (sk->sk_state == TCP_LISTEN)
+			return -EINVAL;
+
+		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
+			answ = 0;
+		else
+			answ = tp->write_seq - tp->snd_una;
+		break;
+	default:
+		return -ENOIOCTLCMD;
+	};
+
+	return put_user(answ, (int __user *)arg);
+}
+
+
+int tcp_listen_start(struct sock *sk)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_listen_opt *lopt;
+
+	sk->sk_max_ack_backlog = 0;
+	sk->sk_ack_backlog = 0;
+	tp->accept_queue = tp->accept_queue_tail = NULL;
+	rwlock_init(&tp->syn_wait_lock);
+	tcp_delack_init(tp);
+
+	lopt = kmalloc(sizeof(struct tcp_listen_opt), GFP_KERNEL);
+	if (!lopt)
+		return -ENOMEM;
+
+	memset(lopt, 0, sizeof(struct tcp_listen_opt));
+	for (lopt->max_qlen_log = 6; ; lopt->max_qlen_log++)
+		if ((1 << lopt->max_qlen_log) >= sysctl_max_syn_backlog)
+			break;
+	get_random_bytes(&lopt->hash_rnd, 4);
+
+	write_lock_bh(&tp->syn_wait_lock);
+	tp->listen_opt = lopt;
+	write_unlock_bh(&tp->syn_wait_lock);
+
+	/* There is race window here: we announce ourselves listening,
+	 * but this transition is still not validated by get_port().
+	 * It is OK, because this socket enters to hash table only
+	 * after validation is complete.
+	 */
+	sk->sk_state = TCP_LISTEN;
+	if (!sk->sk_prot->get_port(sk, inet->num)) {
+		inet->sport = htons(inet->num);
+
+		sk_dst_reset(sk);
+		sk->sk_prot->hash(sk);
+
+		return 0;
+	}
+
+	sk->sk_state = TCP_CLOSE;
+	write_lock_bh(&tp->syn_wait_lock);
+	tp->listen_opt = NULL;
+	write_unlock_bh(&tp->syn_wait_lock);
+	kfree(lopt);
+	return -EADDRINUSE;
+}
+
+/*
+ *	This routine closes sockets which have been at least partially
+ *	opened, but not yet accepted.
+ */
+
+static void tcp_listen_stop (struct sock *sk)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct tcp_listen_opt *lopt = tp->listen_opt;
+	struct open_request *acc_req = tp->accept_queue;
+	struct open_request *req;
+	int i;
+
+	tcp_delete_keepalive_timer(sk);
+
+	/* make all the listen_opt local to us */
+	write_lock_bh(&tp->syn_wait_lock);
+	tp->listen_opt = NULL;
+	write_unlock_bh(&tp->syn_wait_lock);
+	tp->accept_queue = tp->accept_queue_tail = NULL;
+
+	if (lopt->qlen) {
+		for (i = 0; i < TCP_SYNQ_HSIZE; i++) {
+			while ((req = lopt->syn_table[i]) != NULL) {
+				lopt->syn_table[i] = req->dl_next;
+				lopt->qlen--;
+				tcp_openreq_free(req);
+
+		/* Following specs, it would be better either to send FIN
+		 * (and enter FIN-WAIT-1, it is normal close)
+		 * or to send active reset (abort).
+		 * Certainly, it is pretty dangerous while synflood, but it is
+		 * bad justification for our negligence 8)
+		 * To be honest, we are not able to make either
+		 * of the variants now.			--ANK
+		 */
+			}
+		}
+	}
+	BUG_TRAP(!lopt->qlen);
+
+	kfree(lopt);
+
+	while ((req = acc_req) != NULL) {
+		struct sock *child = req->sk;
+
+		acc_req = req->dl_next;
+
+		local_bh_disable();
+		bh_lock_sock(child);
+		BUG_TRAP(!sock_owned_by_user(child));
+		sock_hold(child);
+
+		tcp_disconnect(child, O_NONBLOCK);
+
+		sock_orphan(child);
+
+		atomic_inc(&tcp_orphan_count);
+
+		tcp_destroy_sock(child);
+
+		bh_unlock_sock(child);
+		local_bh_enable();
+		sock_put(child);
+
+		sk_acceptq_removed(sk);
+		tcp_openreq_fastfree(req);
+	}
+	BUG_TRAP(!sk->sk_ack_backlog);
+}
+
+static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
+{
+	TCP_SKB_CB(skb)->flags |= TCPCB_FLAG_PSH;
+	tp->pushed_seq = tp->write_seq;
+}
+
+static inline int forced_push(struct tcp_sock *tp)
+{
+	return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
+}
+
+static inline void skb_entail(struct sock *sk, struct tcp_sock *tp,
+			      struct sk_buff *skb)
+{
+	skb->csum = 0;
+	TCP_SKB_CB(skb)->seq = tp->write_seq;
+	TCP_SKB_CB(skb)->end_seq = tp->write_seq;
+	TCP_SKB_CB(skb)->flags = TCPCB_FLAG_ACK;
+	TCP_SKB_CB(skb)->sacked = 0;
+	skb_header_release(skb);
+	__skb_queue_tail(&sk->sk_write_queue, skb);
+	sk_charge_skb(sk, skb);
+	if (!sk->sk_send_head)
+		sk->sk_send_head = skb;
+	else if (tp->nonagle&TCP_NAGLE_PUSH)
+		tp->nonagle &= ~TCP_NAGLE_PUSH; 
+}
+
+static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
+				struct sk_buff *skb)
+{
+	if (flags & MSG_OOB) {
+		tp->urg_mode = 1;
+		tp->snd_up = tp->write_seq;
+		TCP_SKB_CB(skb)->sacked |= TCPCB_URG;
+	}
+}
+
+static inline void tcp_push(struct sock *sk, struct tcp_sock *tp, int flags,
+			    int mss_now, int nonagle)
+{
+	if (sk->sk_send_head) {
+		struct sk_buff *skb = sk->sk_write_queue.prev;
+		if (!(flags & MSG_MORE) || forced_push(tp))
+			tcp_mark_push(tp, skb);
+		tcp_mark_urg(tp, flags, skb);
+		__tcp_push_pending_frames(sk, tp, mss_now,
+					  (flags & MSG_MORE) ? TCP_NAGLE_CORK : nonagle);
+	}
+}
+
+static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
+			 size_t psize, int flags)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int mss_now;
+	int err;
+	ssize_t copied;
+	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
+
+	/* Wait for a connection to finish. */
+	if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
+		if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
+			goto out_err;
+
+	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+
+	mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
+	copied = 0;
+
+	err = -EPIPE;
+	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+		goto do_error;
+
+	while (psize > 0) {
+		struct sk_buff *skb = sk->sk_write_queue.prev;
+		struct page *page = pages[poffset / PAGE_SIZE];
+		int copy, i, can_coalesce;
+		int offset = poffset % PAGE_SIZE;
+		int size = min_t(size_t, psize, PAGE_SIZE - offset);
+
+		if (!sk->sk_send_head || (copy = mss_now - skb->len) <= 0) {
+new_segment:
+			if (!sk_stream_memory_free(sk))
+				goto wait_for_sndbuf;
+
+			skb = sk_stream_alloc_pskb(sk, 0, 0,
+						   sk->sk_allocation);
+			if (!skb)
+				goto wait_for_memory;
+
+			skb_entail(sk, tp, skb);
+			copy = mss_now;
+		}
+
+		if (copy > size)
+			copy = size;
+
+		i = skb_shinfo(skb)->nr_frags;
+		can_coalesce = skb_can_coalesce(skb, i, page, offset);
+		if (!can_coalesce && i >= MAX_SKB_FRAGS) {
+			tcp_mark_push(tp, skb);
+			goto new_segment;
+		}
+		if (sk->sk_forward_alloc < copy &&
+		    !sk_stream_mem_schedule(sk, copy, 0))
+			goto wait_for_memory;
+		
+		if (can_coalesce) {
+			skb_shinfo(skb)->frags[i - 1].size += copy;
+		} else {
+			get_page(page);
+			skb_fill_page_desc(skb, i, page, offset, copy);
+		}
+
+		skb->len += copy;
+		skb->data_len += copy;
+		skb->truesize += copy;
+		sk->sk_wmem_queued += copy;
+		sk->sk_forward_alloc -= copy;
+		skb->ip_summed = CHECKSUM_HW;
+		tp->write_seq += copy;
+		TCP_SKB_CB(skb)->end_seq += copy;
+		skb_shinfo(skb)->tso_segs = 0;
+
+		if (!copied)
+			TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
+
+		copied += copy;
+		poffset += copy;
+		if (!(psize -= copy))
+			goto out;
+
+		if (skb->len != mss_now || (flags & MSG_OOB))
+			continue;
+
+		if (forced_push(tp)) {
+			tcp_mark_push(tp, skb);
+			__tcp_push_pending_frames(sk, tp, mss_now, TCP_NAGLE_PUSH);
+		} else if (skb == sk->sk_send_head)
+			tcp_push_one(sk, mss_now);
+		continue;
+
+wait_for_sndbuf:
+		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+wait_for_memory:
+		if (copied)
+			tcp_push(sk, tp, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
+
+		if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
+			goto do_error;
+
+		mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
+	}
+
+out:
+	if (copied)
+		tcp_push(sk, tp, flags, mss_now, tp->nonagle);
+	return copied;
+
+do_error:
+	if (copied)
+		goto out;
+out_err:
+	return sk_stream_error(sk, flags, err);
+}
+
+ssize_t tcp_sendpage(struct socket *sock, struct page *page, int offset,
+		     size_t size, int flags)
+{
+	ssize_t res;
+	struct sock *sk = sock->sk;
+
+#define TCP_ZC_CSUM_FLAGS (NETIF_F_IP_CSUM | NETIF_F_NO_CSUM | NETIF_F_HW_CSUM)
+
+	if (!(sk->sk_route_caps & NETIF_F_SG) ||
+	    !(sk->sk_route_caps & TCP_ZC_CSUM_FLAGS))
+		return sock_no_sendpage(sock, page, offset, size, flags);
+
+#undef TCP_ZC_CSUM_FLAGS
+
+	lock_sock(sk);
+	TCP_CHECK_TIMER(sk);
+	res = do_tcp_sendpages(sk, &page, offset, size, flags);
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return res;
+}
+
+#define TCP_PAGE(sk)	(sk->sk_sndmsg_page)
+#define TCP_OFF(sk)	(sk->sk_sndmsg_off)
+
+static inline int select_size(struct sock *sk, struct tcp_sock *tp)
+{
+	int tmp = tp->mss_cache_std;
+
+	if (sk->sk_route_caps & NETIF_F_SG) {
+		int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);
+
+		if (tmp >= pgbreak &&
+		    tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
+			tmp = pgbreak;
+	}
+	return tmp;
+}
+
+int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+		size_t size)
+{
+	struct iovec *iov;
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct sk_buff *skb;
+	int iovlen, flags;
+	int mss_now;
+	int err, copied;
+	long timeo;
+
+	lock_sock(sk);
+	TCP_CHECK_TIMER(sk);
+
+	flags = msg->msg_flags;
+	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);
+
+	/* Wait for a connection to finish. */
+	if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT))
+		if ((err = sk_stream_wait_connect(sk, &timeo)) != 0)
+			goto out_err;
+
+	/* This should be in poll */
+	clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+
+	mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
+
+	/* Ok commence sending. */
+	iovlen = msg->msg_iovlen;
+	iov = msg->msg_iov;
+	copied = 0;
+
+	err = -EPIPE;
+	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
+		goto do_error;
+
+	while (--iovlen >= 0) {
+		int seglen = iov->iov_len;
+		unsigned char __user *from = iov->iov_base;
+
+		iov++;
+
+		while (seglen > 0) {
+			int copy;
+
+			skb = sk->sk_write_queue.prev;
+
+			if (!sk->sk_send_head ||
+			    (copy = mss_now - skb->len) <= 0) {
+
+new_segment:
+				/* Allocate new segment. If the interface is SG,
+				 * allocate skb fitting to single page.
+				 */
+				if (!sk_stream_memory_free(sk))
+					goto wait_for_sndbuf;
+
+				skb = sk_stream_alloc_pskb(sk, select_size(sk, tp),
+							   0, sk->sk_allocation);
+				if (!skb)
+					goto wait_for_memory;
+
+				/*
+				 * Check whether we can use HW checksum.
+				 */
+				if (sk->sk_route_caps &
+				    (NETIF_F_IP_CSUM | NETIF_F_NO_CSUM |
+				     NETIF_F_HW_CSUM))
+					skb->ip_summed = CHECKSUM_HW;
+
+				skb_entail(sk, tp, skb);
+				copy = mss_now;
+			}
+
+			/* Try to append data to the end of skb. */
+			if (copy > seglen)
+				copy = seglen;
+
+			/* Where to copy to? */
+			if (skb_tailroom(skb) > 0) {
+				/* We have some space in skb head. Superb! */
+				if (copy > skb_tailroom(skb))
+					copy = skb_tailroom(skb);
+				if ((err = skb_add_data(skb, from, copy)) != 0)
+					goto do_fault;
+			} else {
+				int merge = 0;
+				int i = skb_shinfo(skb)->nr_frags;
+				struct page *page = TCP_PAGE(sk);
+				int off = TCP_OFF(sk);
+
+				if (skb_can_coalesce(skb, i, page, off) &&
+				    off != PAGE_SIZE) {
+					/* We can extend the last page
+					 * fragment. */
+					merge = 1;
+				} else if (i == MAX_SKB_FRAGS ||
+					   (!i &&
+					   !(sk->sk_route_caps & NETIF_F_SG))) {
+					/* Need to add new fragment and cannot
+					 * do this because interface is non-SG,
+					 * or because all the page slots are
+					 * busy. */
+					tcp_mark_push(tp, skb);
+					goto new_segment;
+				} else if (page) {
+					/* If page is cached, align
+					 * offset to L1 cache boundary
+					 */
+					off = (off + L1_CACHE_BYTES - 1) &
+					      ~(L1_CACHE_BYTES - 1);
+					if (off == PAGE_SIZE) {
+						put_page(page);
+						TCP_PAGE(sk) = page = NULL;
+					}
+				}
+
+				if (!page) {
+					/* Allocate new cache page. */
+					if (!(page = sk_stream_alloc_page(sk)))
+						goto wait_for_memory;
+					off = 0;
+				}
+
+				if (copy > PAGE_SIZE - off)
+					copy = PAGE_SIZE - off;
+
+				/* Time to copy data. We are close to
+				 * the end! */
+				err = skb_copy_to_page(sk, from, skb, page,
+						       off, copy);
+				if (err) {
+					/* If this page was new, give it to the
+					 * socket so it does not get leaked.
+					 */
+					if (!TCP_PAGE(sk)) {
+						TCP_PAGE(sk) = page;
+						TCP_OFF(sk) = 0;
+					}
+					goto do_error;
+				}
+
+				/* Update the skb. */
+				if (merge) {
+					skb_shinfo(skb)->frags[i - 1].size +=
+									copy;
+				} else {
+					skb_fill_page_desc(skb, i, page, off, copy);
+					if (TCP_PAGE(sk)) {
+						get_page(page);
+					} else if (off + copy < PAGE_SIZE) {
+						get_page(page);
+						TCP_PAGE(sk) = page;
+					}
+				}
+
+				TCP_OFF(sk) = off + copy;
+			}
+
+			if (!copied)
+				TCP_SKB_CB(skb)->flags &= ~TCPCB_FLAG_PSH;
+
+			tp->write_seq += copy;
+			TCP_SKB_CB(skb)->end_seq += copy;
+			skb_shinfo(skb)->tso_segs = 0;
+
+			from += copy;
+			copied += copy;
+			if ((seglen -= copy) == 0 && iovlen == 0)
+				goto out;
+
+			if (skb->len != mss_now || (flags & MSG_OOB))
+				continue;
+
+			if (forced_push(tp)) {
+				tcp_mark_push(tp, skb);
+				__tcp_push_pending_frames(sk, tp, mss_now, TCP_NAGLE_PUSH);
+			} else if (skb == sk->sk_send_head)
+				tcp_push_one(sk, mss_now);
+			continue;
+
+wait_for_sndbuf:
+			set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
+wait_for_memory:
+			if (copied)
+				tcp_push(sk, tp, flags & ~MSG_MORE, mss_now, TCP_NAGLE_PUSH);
+
+			if ((err = sk_stream_wait_memory(sk, &timeo)) != 0)
+				goto do_error;
+
+			mss_now = tcp_current_mss(sk, !(flags&MSG_OOB));
+		}
+	}
+
+out:
+	if (copied)
+		tcp_push(sk, tp, flags, mss_now, tp->nonagle);
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return copied;
+
+do_fault:
+	if (!skb->len) {
+		if (sk->sk_send_head == skb)
+			sk->sk_send_head = NULL;
+		__skb_unlink(skb, skb->list);
+		sk_stream_free_skb(sk, skb);
+	}
+
+do_error:
+	if (copied)
+		goto out;
+out_err:
+	err = sk_stream_error(sk, flags, err);
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return err;
+}
+
+/*
+ *	Handle reading urgent data. BSD has very simple semantics for
+ *	this, no blocking and very strange errors 8)
+ */
+
+static int tcp_recv_urg(struct sock *sk, long timeo,
+			struct msghdr *msg, int len, int flags,
+			int *addr_len)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	/* No URG data to read. */
+	if (sock_flag(sk, SOCK_URGINLINE) || !tp->urg_data ||
+	    tp->urg_data == TCP_URG_READ)
+		return -EINVAL;	/* Yes this is right ! */
+
+	if (sk->sk_state == TCP_CLOSE && !sock_flag(sk, SOCK_DONE))
+		return -ENOTCONN;
+
+	if (tp->urg_data & TCP_URG_VALID) {
+		int err = 0;
+		char c = tp->urg_data;
+
+		if (!(flags & MSG_PEEK))
+			tp->urg_data = TCP_URG_READ;
+
+		/* Read urgent data. */
+		msg->msg_flags |= MSG_OOB;
+
+		if (len > 0) {
+			if (!(flags & MSG_TRUNC))
+				err = memcpy_toiovec(msg->msg_iov, &c, 1);
+			len = 1;
+		} else
+			msg->msg_flags |= MSG_TRUNC;
+
+		return err ? -EFAULT : len;
+	}
+
+	if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN))
+		return 0;
+
+	/* Fixed the recv(..., MSG_OOB) behaviour.  BSD docs and
+	 * the available implementations agree in this case:
+	 * this call should never block, independent of the
+	 * blocking state of the socket.
+	 * Mike <pall@rz.uni-karlsruhe.de>
+	 */
+	return -EAGAIN;
+}
+
+/* Clean up the receive buffer for full frames taken by the user,
+ * then send an ACK if necessary.  COPIED is the number of bytes
+ * tcp_recvmsg has given to the user so far, it speeds up the
+ * calculation of whether or not we must ACK for the sake of
+ * a window update.
+ */
+static void cleanup_rbuf(struct sock *sk, int copied)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int time_to_ack = 0;
+
+#if TCP_DEBUG
+	struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
+
+	BUG_TRAP(!skb || before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq));
+#endif
+
+	if (tcp_ack_scheduled(tp)) {
+		   /* Delayed ACKs frequently hit locked sockets during bulk
+		    * receive. */
+		if (tp->ack.blocked ||
+		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
+		    tp->rcv_nxt - tp->rcv_wup > tp->ack.rcv_mss ||
+		    /*
+		     * If this read emptied read buffer, we send ACK, if
+		     * connection is not bidirectional, user drained
+		     * receive buffer and there was a small segment
+		     * in queue.
+		     */
+		    (copied > 0 && (tp->ack.pending & TCP_ACK_PUSHED) &&
+		     !tp->ack.pingpong && !atomic_read(&sk->sk_rmem_alloc)))
+			time_to_ack = 1;
+	}
+
+	/* We send an ACK if we can now advertise a non-zero window
+	 * which has been raised "significantly".
+	 *
+	 * Even if window raised up to infinity, do not send window open ACK
+	 * in states, where we will not receive more. It is useless.
+	 */
+	if (copied > 0 && !time_to_ack && !(sk->sk_shutdown & RCV_SHUTDOWN)) {
+		__u32 rcv_window_now = tcp_receive_window(tp);
+
+		/* Optimize, __tcp_select_window() is not cheap. */
+		if (2*rcv_window_now <= tp->window_clamp) {
+			__u32 new_window = __tcp_select_window(sk);
+
+			/* Send ACK now, if this read freed lots of space
+			 * in our buffer. Certainly, new_window is new window.
+			 * We can advertise it now, if it is not less than current one.
+			 * "Lots" means "at least twice" here.
+			 */
+			if (new_window && new_window >= 2 * rcv_window_now)
+				time_to_ack = 1;
+		}
+	}
+	if (time_to_ack)
+		tcp_send_ack(sk);
+}
+
+static void tcp_prequeue_process(struct sock *sk)
+{
+	struct sk_buff *skb;
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	NET_ADD_STATS_USER(LINUX_MIB_TCPPREQUEUED, skb_queue_len(&tp->ucopy.prequeue));
+
+	/* RX process wants to run with disabled BHs, though it is not
+	 * necessary */
+	local_bh_disable();
+	while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
+		sk->sk_backlog_rcv(sk, skb);
+	local_bh_enable();
+
+	/* Clear memory counter. */
+	tp->ucopy.memory = 0;
+}
+
+static inline struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
+{
+	struct sk_buff *skb;
+	u32 offset;
+
+	skb_queue_walk(&sk->sk_receive_queue, skb) {
+		offset = seq - TCP_SKB_CB(skb)->seq;
+		if (skb->h.th->syn)
+			offset--;
+		if (offset < skb->len || skb->h.th->fin) {
+			*off = offset;
+			return skb;
+		}
+	}
+	return NULL;
+}
+
+/*
+ * This routine provides an alternative to tcp_recvmsg() for routines
+ * that would like to handle copying from skbuffs directly in 'sendfile'
+ * fashion.
+ * Note:
+ *	- It is assumed that the socket was locked by the caller.
+ *	- The routine does not block.
+ *	- At present, there is no support for reading OOB data
+ *	  or for 'peeking' the socket using this routine
+ *	  (although both would be easy to implement).
+ */
+int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
+		  sk_read_actor_t recv_actor)
+{
+	struct sk_buff *skb;
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 seq = tp->copied_seq;
+	u32 offset;
+	int copied = 0;
+
+	if (sk->sk_state == TCP_LISTEN)
+		return -ENOTCONN;
+	while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
+		if (offset < skb->len) {
+			size_t used, len;
+
+			len = skb->len - offset;
+			/* Stop reading if we hit a patch of urgent data */
+			if (tp->urg_data) {
+				u32 urg_offset = tp->urg_seq - seq;
+				if (urg_offset < len)
+					len = urg_offset;
+				if (!len)
+					break;
+			}
+			used = recv_actor(desc, skb, offset, len);
+			if (used <= len) {
+				seq += used;
+				copied += used;
+				offset += used;
+			}
+			if (offset != skb->len)
+				break;
+		}
+		if (skb->h.th->fin) {
+			sk_eat_skb(sk, skb);
+			++seq;
+			break;
+		}
+		sk_eat_skb(sk, skb);
+		if (!desc->count)
+			break;
+	}
+	tp->copied_seq = seq;
+
+	tcp_rcv_space_adjust(sk);
+
+	/* Clean up data we have read: This will do ACK frames. */
+	if (copied)
+		cleanup_rbuf(sk, copied);
+	return copied;
+}
+
+/*
+ *	This routine copies from a sock struct into the user buffer.
+ *
+ *	Technical note: in 2.3 we work on _locked_ socket, so that
+ *	tricks with *seq access order and skb->users are not required.
+ *	Probably, code can be easily improved even more.
+ */
+
+int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
+		size_t len, int nonblock, int flags, int *addr_len)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int copied = 0;
+	u32 peek_seq;
+	u32 *seq;
+	unsigned long used;
+	int err;
+	int target;		/* Read at least this many bytes */
+	long timeo;
+	struct task_struct *user_recv = NULL;
+
+	lock_sock(sk);
+
+	TCP_CHECK_TIMER(sk);
+
+	err = -ENOTCONN;
+	if (sk->sk_state == TCP_LISTEN)
+		goto out;
+
+	timeo = sock_rcvtimeo(sk, nonblock);
+
+	/* Urgent data needs to be handled specially. */
+	if (flags & MSG_OOB)
+		goto recv_urg;
+
+	seq = &tp->copied_seq;
+	if (flags & MSG_PEEK) {
+		peek_seq = tp->copied_seq;
+		seq = &peek_seq;
+	}
+
+	target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
+
+	do {
+		struct sk_buff *skb;
+		u32 offset;
+
+		/* Are we at urgent data? Stop if we have read anything or have SIGURG pending. */
+		if (tp->urg_data && tp->urg_seq == *seq) {
+			if (copied)
+				break;
+			if (signal_pending(current)) {
+				copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
+				break;
+			}
+		}
+
+		/* Next get a buffer. */
+
+		skb = skb_peek(&sk->sk_receive_queue);
+		do {
+			if (!skb)
+				break;
+
+			/* Now that we have two receive queues this
+			 * shouldn't happen.
+			 */
+			if (before(*seq, TCP_SKB_CB(skb)->seq)) {
+				printk(KERN_INFO "recvmsg bug: copied %X "
+				       "seq %X\n", *seq, TCP_SKB_CB(skb)->seq);
+				break;
+			}
+			offset = *seq - TCP_SKB_CB(skb)->seq;
+			if (skb->h.th->syn)
+				offset--;
+			if (offset < skb->len)
+				goto found_ok_skb;
+			if (skb->h.th->fin)
+				goto found_fin_ok;
+			BUG_TRAP(flags & MSG_PEEK);
+			skb = skb->next;
+		} while (skb != (struct sk_buff *)&sk->sk_receive_queue);
+
+		/* Well, if we have backlog, try to process it now yet. */
+
+		if (copied >= target && !sk->sk_backlog.tail)
+			break;
+
+		if (copied) {
+			if (sk->sk_err ||
+			    sk->sk_state == TCP_CLOSE ||
+			    (sk->sk_shutdown & RCV_SHUTDOWN) ||
+			    !timeo ||
+			    signal_pending(current) ||
+			    (flags & MSG_PEEK))
+				break;
+		} else {
+			if (sock_flag(sk, SOCK_DONE))
+				break;
+
+			if (sk->sk_err) {
+				copied = sock_error(sk);
+				break;
+			}
+
+			if (sk->sk_shutdown & RCV_SHUTDOWN)
+				break;
+
+			if (sk->sk_state == TCP_CLOSE) {
+				if (!sock_flag(sk, SOCK_DONE)) {
+					/* This occurs when user tries to read
+					 * from never connected socket.
+					 */
+					copied = -ENOTCONN;
+					break;
+				}
+				break;
+			}
+
+			if (!timeo) {
+				copied = -EAGAIN;
+				break;
+			}
+
+			if (signal_pending(current)) {
+				copied = sock_intr_errno(timeo);
+				break;
+			}
+		}
+
+		cleanup_rbuf(sk, copied);
+
+		if (tp->ucopy.task == user_recv) {
+			/* Install new reader */
+			if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
+				user_recv = current;
+				tp->ucopy.task = user_recv;
+				tp->ucopy.iov = msg->msg_iov;
+			}
+
+			tp->ucopy.len = len;
+
+			BUG_TRAP(tp->copied_seq == tp->rcv_nxt ||
+				 (flags & (MSG_PEEK | MSG_TRUNC)));
+
+			/* Ugly... If prequeue is not empty, we have to
+			 * process it before releasing socket, otherwise
+			 * order will be broken at second iteration.
+			 * More elegant solution is required!!!
+			 *
+			 * Look: we have the following (pseudo)queues:
+			 *
+			 * 1. packets in flight
+			 * 2. backlog
+			 * 3. prequeue
+			 * 4. receive_queue
+			 *
+			 * Each queue can be processed only if the next ones
+			 * are empty. At this point we have empty receive_queue.
+			 * But prequeue _can_ be not empty after 2nd iteration,
+			 * when we jumped to start of loop because backlog
+			 * processing added something to receive_queue.
+			 * We cannot release_sock(), because backlog contains
+			 * packets arrived _after_ prequeued ones.
+			 *
+			 * Shortly, algorithm is clear --- to process all
+			 * the queues in order. We could make it more directly,
+			 * requeueing packets from backlog to prequeue, if
+			 * is not empty. It is more elegant, but eats cycles,
+			 * unfortunately.
+			 */
+			if (skb_queue_len(&tp->ucopy.prequeue))
+				goto do_prequeue;
+
+			/* __ Set realtime policy in scheduler __ */
+		}
+
+		if (copied >= target) {
+			/* Do not sleep, just process backlog. */
+			release_sock(sk);
+			lock_sock(sk);
+		} else
+			sk_wait_data(sk, &timeo);
+
+		if (user_recv) {
+			int chunk;
+
+			/* __ Restore normal policy in scheduler __ */
+
+			if ((chunk = len - tp->ucopy.len) != 0) {
+				NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
+				len -= chunk;
+				copied += chunk;
+			}
+
+			if (tp->rcv_nxt == tp->copied_seq &&
+			    skb_queue_len(&tp->ucopy.prequeue)) {
+do_prequeue:
+				tcp_prequeue_process(sk);
+
+				if ((chunk = len - tp->ucopy.len) != 0) {
+					NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
+					len -= chunk;
+					copied += chunk;
+				}
+			}
+		}
+		if ((flags & MSG_PEEK) && peek_seq != tp->copied_seq) {
+			if (net_ratelimit())
+				printk(KERN_DEBUG "TCP(%s:%d): Application bug, race in MSG_PEEK.\n",
+				       current->comm, current->pid);
+			peek_seq = tp->copied_seq;
+		}
+		continue;
+
+	found_ok_skb:
+		/* Ok so how much can we use? */
+		used = skb->len - offset;
+		if (len < used)
+			used = len;
+
+		/* Do we have urgent data here? */
+		if (tp->urg_data) {
+			u32 urg_offset = tp->urg_seq - *seq;
+			if (urg_offset < used) {
+				if (!urg_offset) {
+					if (!sock_flag(sk, SOCK_URGINLINE)) {
+						++*seq;
+						offset++;
+						used--;
+						if (!used)
+							goto skip_copy;
+					}
+				} else
+					used = urg_offset;
+			}
+		}
+
+		if (!(flags & MSG_TRUNC)) {
+			err = skb_copy_datagram_iovec(skb, offset,
+						      msg->msg_iov, used);
+			if (err) {
+				/* Exception. Bailout! */
+				if (!copied)
+					copied = -EFAULT;
+				break;
+			}
+		}
+
+		*seq += used;
+		copied += used;
+		len -= used;
+
+		tcp_rcv_space_adjust(sk);
+
+skip_copy:
+		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
+			tp->urg_data = 0;
+			tcp_fast_path_check(sk, tp);
+		}
+		if (used + offset < skb->len)
+			continue;
+
+		if (skb->h.th->fin)
+			goto found_fin_ok;
+		if (!(flags & MSG_PEEK))
+			sk_eat_skb(sk, skb);
+		continue;
+
+	found_fin_ok:
+		/* Process the FIN. */
+		++*seq;
+		if (!(flags & MSG_PEEK))
+			sk_eat_skb(sk, skb);
+		break;
+	} while (len > 0);
+
+	if (user_recv) {
+		if (skb_queue_len(&tp->ucopy.prequeue)) {
+			int chunk;
+
+			tp->ucopy.len = copied > 0 ? len : 0;
+
+			tcp_prequeue_process(sk);
+
+			if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
+				NET_ADD_STATS_USER(LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
+				len -= chunk;
+				copied += chunk;
+			}
+		}
+
+		tp->ucopy.task = NULL;
+		tp->ucopy.len = 0;
+	}
+
+	/* According to UNIX98, msg_name/msg_namelen are ignored
+	 * on connected socket. I was just happy when found this 8) --ANK
+	 */
+
+	/* Clean up data we have read: This will do ACK frames. */
+	cleanup_rbuf(sk, copied);
+
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return copied;
+
+out:
+	TCP_CHECK_TIMER(sk);
+	release_sock(sk);
+	return err;
+
+recv_urg:
+	err = tcp_recv_urg(sk, timeo, msg, len, flags, addr_len);
+	goto out;
+}
+
+/*
+ *	State processing on a close. This implements the state shift for
+ *	sending our FIN frame. Note that we only send a FIN for some
+ *	states. A shutdown() may have already sent the FIN, or we may be
+ *	closed.
+ */
+
+static unsigned char new_state[16] = {
+  /* current state:        new state:      action:	*/
+  /* (Invalid)		*/ TCP_CLOSE,
+  /* TCP_ESTABLISHED	*/ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
+  /* TCP_SYN_SENT	*/ TCP_CLOSE,
+  /* TCP_SYN_RECV	*/ TCP_FIN_WAIT1 | TCP_ACTION_FIN,
+  /* TCP_FIN_WAIT1	*/ TCP_FIN_WAIT1,
+  /* TCP_FIN_WAIT2	*/ TCP_FIN_WAIT2,
+  /* TCP_TIME_WAIT	*/ TCP_CLOSE,
+  /* TCP_CLOSE		*/ TCP_CLOSE,
+  /* TCP_CLOSE_WAIT	*/ TCP_LAST_ACK  | TCP_ACTION_FIN,
+  /* TCP_LAST_ACK	*/ TCP_LAST_ACK,
+  /* TCP_LISTEN		*/ TCP_CLOSE,
+  /* TCP_CLOSING	*/ TCP_CLOSING,
+};
+
+static int tcp_close_state(struct sock *sk)
+{
+	int next = (int)new_state[sk->sk_state];
+	int ns = next & TCP_STATE_MASK;
+
+	tcp_set_state(sk, ns);
+
+	return next & TCP_ACTION_FIN;
+}
+
+/*
+ *	Shutdown the sending side of a connection. Much like close except
+ *	that we don't receive shut down or set_sock_flag(sk, SOCK_DEAD).
+ */
+
+void tcp_shutdown(struct sock *sk, int how)
+{
+	/*	We need to grab some memory, and put together a FIN,
+	 *	and then put it into the queue to be sent.
+	 *		Tim MacKenzie(tym@dibbler.cs.monash.edu.au) 4 Dec '92.
+	 */
+	if (!(how & SEND_SHUTDOWN))
+		return;
+
+	/* If we've already sent a FIN, or it's a closed state, skip this. */
+	if ((1 << sk->sk_state) &
+	    (TCPF_ESTABLISHED | TCPF_SYN_SENT |
+	     TCPF_SYN_RECV | TCPF_CLOSE_WAIT)) {
+		/* Clear out any half completed packets.  FIN if needed. */
+		if (tcp_close_state(sk))
+			tcp_send_fin(sk);
+	}
+}
+
+/*
+ * At this point, there should be no process reference to this
+ * socket, and thus no user references at all.  Therefore we
+ * can assume the socket waitqueue is inactive and nobody will
+ * try to jump onto it.
+ */
+void tcp_destroy_sock(struct sock *sk)
+{
+	BUG_TRAP(sk->sk_state == TCP_CLOSE);
+	BUG_TRAP(sock_flag(sk, SOCK_DEAD));
+
+	/* It cannot be in hash table! */
+	BUG_TRAP(sk_unhashed(sk));
+
+	/* If it has not 0 inet_sk(sk)->num, it must be bound */
+	BUG_TRAP(!inet_sk(sk)->num || tcp_sk(sk)->bind_hash);
+
+	sk->sk_prot->destroy(sk);
+
+	sk_stream_kill_queues(sk);
+
+	xfrm_sk_free_policy(sk);
+
+#ifdef INET_REFCNT_DEBUG
+	if (atomic_read(&sk->sk_refcnt) != 1) {
+		printk(KERN_DEBUG "Destruction TCP %p delayed, c=%d\n",
+		       sk, atomic_read(&sk->sk_refcnt));
+	}
+#endif
+
+	atomic_dec(&tcp_orphan_count);
+	sock_put(sk);
+}
+
+void tcp_close(struct sock *sk, long timeout)
+{
+	struct sk_buff *skb;
+	int data_was_unread = 0;
+
+	lock_sock(sk);
+	sk->sk_shutdown = SHUTDOWN_MASK;
+
+	if (sk->sk_state == TCP_LISTEN) {
+		tcp_set_state(sk, TCP_CLOSE);
+
+		/* Special case. */
+		tcp_listen_stop(sk);
+
+		goto adjudge_to_death;
+	}
+
+	/*  We need to flush the recv. buffs.  We do this only on the
+	 *  descriptor close, not protocol-sourced closes, because the
+	 *  reader process may not have drained the data yet!
+	 */
+	while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+		u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq -
+			  skb->h.th->fin;
+		data_was_unread += len;
+		__kfree_skb(skb);
+	}
+
+	sk_stream_mem_reclaim(sk);
+
+	/* As outlined in draft-ietf-tcpimpl-prob-03.txt, section
+	 * 3.10, we send a RST here because data was lost.  To
+	 * witness the awful effects of the old behavior of always
+	 * doing a FIN, run an older 2.1.x kernel or 2.0.x, start
+	 * a bulk GET in an FTP client, suspend the process, wait
+	 * for the client to advertise a zero window, then kill -9
+	 * the FTP client, wheee...  Note: timeout is always zero
+	 * in such a case.
+	 */
+	if (data_was_unread) {
+		/* Unread data was tossed, zap the connection. */
+		NET_INC_STATS_USER(LINUX_MIB_TCPABORTONCLOSE);
+		tcp_set_state(sk, TCP_CLOSE);
+		tcp_send_active_reset(sk, GFP_KERNEL);
+	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
+		/* Check zero linger _after_ checking for unread data. */
+		sk->sk_prot->disconnect(sk, 0);
+		NET_INC_STATS_USER(LINUX_MIB_TCPABORTONDATA);
+	} else if (tcp_close_state(sk)) {
+		/* We FIN if the application ate all the data before
+		 * zapping the connection.
+		 */
+
+		/* RED-PEN. Formally speaking, we have broken TCP state
+		 * machine. State transitions:
+		 *
+		 * TCP_ESTABLISHED -> TCP_FIN_WAIT1
+		 * TCP_SYN_RECV	-> TCP_FIN_WAIT1 (forget it, it's impossible)
+		 * TCP_CLOSE_WAIT -> TCP_LAST_ACK
+		 *
+		 * are legal only when FIN has been sent (i.e. in window),
+		 * rather than queued out of window. Purists blame.
+		 *
+		 * F.e. "RFC state" is ESTABLISHED,
+		 * if Linux state is FIN-WAIT-1, but FIN is still not sent.
+		 *
+		 * The visible declinations are that sometimes
+		 * we enter time-wait state, when it is not required really
+		 * (harmless), do not send active resets, when they are
+		 * required by specs (TCP_ESTABLISHED, TCP_CLOSE_WAIT, when
+		 * they look as CLOSING or LAST_ACK for Linux)
+		 * Probably, I missed some more holelets.
+		 * 						--ANK
+		 */
+		tcp_send_fin(sk);
+	}
+
+	sk_stream_wait_close(sk, timeout);
+
+adjudge_to_death:
+	/* It is the last release_sock in its life. It will remove backlog. */
+	release_sock(sk);
+
+
+	/* Now socket is owned by kernel and we acquire BH lock
+	   to finish close. No need to check for user refs.
+	 */
+	local_bh_disable();
+	bh_lock_sock(sk);
+	BUG_TRAP(!sock_owned_by_user(sk));
+
+	sock_hold(sk);
+	sock_orphan(sk);
+
+	/*	This is a (useful) BSD violating of the RFC. There is a
+	 *	problem with TCP as specified in that the other end could
+	 *	keep a socket open forever with no application left this end.
+	 *	We use a 3 minute timeout (about the same as BSD) then kill
+	 *	our end. If they send after that then tough - BUT: long enough
+	 *	that we won't make the old 4*rto = almost no time - whoops
+	 *	reset mistake.
+	 *
+	 *	Nope, it was not mistake. It is really desired behaviour
+	 *	f.e. on http servers, when such sockets are useless, but
+	 *	consume significant resources. Let's do it with special
+	 *	linger2	option.					--ANK
+	 */
+
+	if (sk->sk_state == TCP_FIN_WAIT2) {
+		struct tcp_sock *tp = tcp_sk(sk);
+		if (tp->linger2 < 0) {
+			tcp_set_state(sk, TCP_CLOSE);
+			tcp_send_active_reset(sk, GFP_ATOMIC);
+			NET_INC_STATS_BH(LINUX_MIB_TCPABORTONLINGER);
+		} else {
+			int tmo = tcp_fin_time(tp);
+
+			if (tmo > TCP_TIMEWAIT_LEN) {
+				tcp_reset_keepalive_timer(sk, tcp_fin_time(tp));
+			} else {
+				atomic_inc(&tcp_orphan_count);
+				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
+				goto out;
+			}
+		}
+	}
+	if (sk->sk_state != TCP_CLOSE) {
+		sk_stream_mem_reclaim(sk);
+		if (atomic_read(&tcp_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())
+				printk(KERN_INFO "TCP: too many of orphaned "
+				       "sockets\n");
+			tcp_set_state(sk, TCP_CLOSE);
+			tcp_send_active_reset(sk, GFP_ATOMIC);
+			NET_INC_STATS_BH(LINUX_MIB_TCPABORTONMEMORY);
+		}
+	}
+	atomic_inc(&tcp_orphan_count);
+
+	if (sk->sk_state == TCP_CLOSE)
+		tcp_destroy_sock(sk);
+	/* Otherwise, socket is reprieved until protocol close. */
+
+out:
+	bh_unlock_sock(sk);
+	local_bh_enable();
+	sock_put(sk);
+}
+
+/* These states need RST on ABORT according to RFC793 */
+
+static inline int tcp_need_reset(int state)
+{
+	return (1 << state) &
+	       (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
+		TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
+}
+
+int tcp_disconnect(struct sock *sk, int flags)
+{
+	struct inet_sock *inet = inet_sk(sk);
+	struct tcp_sock *tp = tcp_sk(sk);
+	int err = 0;
+	int old_state = sk->sk_state;
+
+	if (old_state != TCP_CLOSE)
+		tcp_set_state(sk, TCP_CLOSE);
+
+	/* ABORT function of RFC793 */
+	if (old_state == TCP_LISTEN) {
+		tcp_listen_stop(sk);
+	} else if (tcp_need_reset(old_state) ||
+		   (tp->snd_nxt != tp->write_seq &&
+		    (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
+		/* The last check adjusts for discrepance of Linux wrt. RFC
+		 * states
+		 */
+		tcp_send_active_reset(sk, gfp_any());
+		sk->sk_err = ECONNRESET;
+	} else if (old_state == TCP_SYN_SENT)
+		sk->sk_err = ECONNRESET;
+
+	tcp_clear_xmit_timers(sk);
+	__skb_queue_purge(&sk->sk_receive_queue);
+	sk_stream_writequeue_purge(sk);
+	__skb_queue_purge(&tp->out_of_order_queue);
+
+	inet->dport = 0;
+
+	if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
+		inet_reset_saddr(sk);
+
+	sk->sk_shutdown = 0;
+	sock_reset_flag(sk, SOCK_DONE);
+	tp->srtt = 0;
+	if ((tp->write_seq += tp->max_window + 2) == 0)
+		tp->write_seq = 1;
+	tp->backoff = 0;
+	tp->snd_cwnd = 2;
+	tp->probes_out = 0;
+	tp->packets_out = 0;
+	tp->snd_ssthresh = 0x7fffffff;
+	tp->snd_cwnd_cnt = 0;
+	tcp_set_ca_state(tp, TCP_CA_Open);
+	tcp_clear_retrans(tp);
+	tcp_delack_init(tp);
+	sk->sk_send_head = NULL;
+	tp->rx_opt.saw_tstamp = 0;
+	tcp_sack_reset(&tp->rx_opt);
+	__sk_dst_reset(sk);
+
+	BUG_TRAP(!inet->num || tp->bind_hash);
+
+	sk->sk_error_report(sk);
+	return err;
+}
+
+/*
+ *	Wait for an incoming connection, avoid race
+ *	conditions. This must be called with the socket locked.
+ */
+static int wait_for_connect(struct sock *sk, long timeo)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	DEFINE_WAIT(wait);
+	int err;
+
+	/*
+	 * True wake-one mechanism for incoming connections: only
+	 * one process gets woken up, not the 'whole herd'.
+	 * Since we do not 'race & poll' for established sockets
+	 * anymore, the common case will execute the loop only once.
+	 *
+	 * Subtle issue: "add_wait_queue_exclusive()" will be added
+	 * after any current non-exclusive waiters, and we know that
+	 * it will always _stay_ after any new non-exclusive waiters
+	 * because all non-exclusive waiters are added at the
+	 * beginning of the wait-queue. As such, it's ok to "drop"
+	 * our exclusiveness temporarily when we get woken up without
+	 * having to remove and re-insert us on the wait queue.
+	 */
+	for (;;) {
+		prepare_to_wait_exclusive(sk->sk_sleep, &wait,
+					  TASK_INTERRUPTIBLE);
+		release_sock(sk);
+		if (!tp->accept_queue)
+			timeo = schedule_timeout(timeo);
+		lock_sock(sk);
+		err = 0;
+		if (tp->accept_queue)
+			break;
+		err = -EINVAL;
+		if (sk->sk_state != TCP_LISTEN)
+			break;
+		err = sock_intr_errno(timeo);
+		if (signal_pending(current))
+			break;
+		err = -EAGAIN;
+		if (!timeo)
+			break;
+	}
+	finish_wait(sk->sk_sleep, &wait);
+	return err;
+}
+
+/*
+ *	This will accept the next outstanding connection.
+ */
+
+struct sock *tcp_accept(struct sock *sk, int flags, int *err)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	struct open_request *req;
+	struct sock *newsk;
+	int error;
+
+	lock_sock(sk);
+
+	/* We need to make sure that this socket is listening,
+	 * and that it has something pending.
+	 */
+	error = -EINVAL;
+	if (sk->sk_state != TCP_LISTEN)
+		goto out;
+
+	/* Find already established connection */
+	if (!tp->accept_queue) {
+		long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
+
+		/* If this is a non blocking socket don't sleep */
+		error = -EAGAIN;
+		if (!timeo)
+			goto out;
+
+		error = wait_for_connect(sk, timeo);
+		if (error)
+			goto out;
+	}
+
+	req = tp->accept_queue;
+	if ((tp->accept_queue = req->dl_next) == NULL)
+		tp->accept_queue_tail = NULL;
+
+ 	newsk = req->sk;
+	sk_acceptq_removed(sk);
+	tcp_openreq_fastfree(req);
+	BUG_TRAP(newsk->sk_state != TCP_SYN_RECV);
+	release_sock(sk);
+	return newsk;
+
+out:
+	release_sock(sk);
+	*err = error;
+	return NULL;
+}
+
+/*
+ *	Socket option code for TCP.
+ */
+int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
+		   int optlen)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int val;
+	int err = 0;
+
+	if (level != SOL_TCP)
+		return tp->af_specific->setsockopt(sk, level, optname,
+						   optval, optlen);
+
+	if (optlen < sizeof(int))
+		return -EINVAL;
+
+	if (get_user(val, (int __user *)optval))
+		return -EFAULT;
+
+	lock_sock(sk);
+
+	switch (optname) {
+	case TCP_MAXSEG:
+		/* Values greater than interface MTU won't take effect. However
+		 * at the point when this call is done we typically don't yet
+		 * know which interface is going to be used */
+		if (val < 8 || val > MAX_TCP_WINDOW) {
+			err = -EINVAL;
+			break;
+		}
+		tp->rx_opt.user_mss = val;
+		break;
+
+	case TCP_NODELAY:
+		if (val) {
+			/* TCP_NODELAY is weaker than TCP_CORK, so that
+			 * this option on corked socket is remembered, but
+			 * it is not activated until cork is cleared.
+			 *
+			 * However, when TCP_NODELAY is set we make
+			 * an explicit push, which overrides even TCP_CORK
+			 * for currently queued segments.
+			 */
+			tp->nonagle |= TCP_NAGLE_OFF|TCP_NAGLE_PUSH;
+			tcp_push_pending_frames(sk, tp);
+		} else {
+			tp->nonagle &= ~TCP_NAGLE_OFF;
+		}
+		break;
+
+	case TCP_CORK:
+		/* When set indicates to always queue non-full frames.
+		 * Later the user clears this option and we transmit
+		 * any pending partial frames in the queue.  This is
+		 * meant to be used alongside sendfile() to get properly
+		 * filled frames when the user (for example) must write
+		 * out headers with a write() call first and then use
+		 * sendfile to send out the data parts.
+		 *
+		 * TCP_CORK can be set together with TCP_NODELAY and it is
+		 * stronger than TCP_NODELAY.
+		 */
+		if (val) {
+			tp->nonagle |= TCP_NAGLE_CORK;
+		} else {
+			tp->nonagle &= ~TCP_NAGLE_CORK;
+			if (tp->nonagle&TCP_NAGLE_OFF)
+				tp->nonagle |= TCP_NAGLE_PUSH;
+			tcp_push_pending_frames(sk, tp);
+		}
+		break;
+
+	case TCP_KEEPIDLE:
+		if (val < 1 || val > MAX_TCP_KEEPIDLE)
+			err = -EINVAL;
+		else {
+			tp->keepalive_time = val * HZ;
+			if (sock_flag(sk, SOCK_KEEPOPEN) &&
+			    !((1 << sk->sk_state) &
+			      (TCPF_CLOSE | TCPF_LISTEN))) {
+				__u32 elapsed = tcp_time_stamp - tp->rcv_tstamp;
+				if (tp->keepalive_time > elapsed)
+					elapsed = tp->keepalive_time - elapsed;
+				else
+					elapsed = 0;
+				tcp_reset_keepalive_timer(sk, elapsed);
+			}
+		}
+		break;
+	case TCP_KEEPINTVL:
+		if (val < 1 || val > MAX_TCP_KEEPINTVL)
+			err = -EINVAL;
+		else
+			tp->keepalive_intvl = val * HZ;
+		break;
+	case TCP_KEEPCNT:
+		if (val < 1 || val > MAX_TCP_KEEPCNT)
+			err = -EINVAL;
+		else
+			tp->keepalive_probes = val;
+		break;
+	case TCP_SYNCNT:
+		if (val < 1 || val > MAX_TCP_SYNCNT)
+			err = -EINVAL;
+		else
+			tp->syn_retries = val;
+		break;
+
+	case TCP_LINGER2:
+		if (val < 0)
+			tp->linger2 = -1;
+		else if (val > sysctl_tcp_fin_timeout / HZ)
+			tp->linger2 = 0;
+		else
+			tp->linger2 = val * HZ;
+		break;
+
+	case TCP_DEFER_ACCEPT:
+		tp->defer_accept = 0;
+		if (val > 0) {
+			/* Translate value in seconds to number of
+			 * retransmits */
+			while (tp->defer_accept < 32 &&
+			       val > ((TCP_TIMEOUT_INIT / HZ) <<
+				       tp->defer_accept))
+				tp->defer_accept++;
+			tp->defer_accept++;
+		}
+		break;
+
+	case TCP_WINDOW_CLAMP:
+		if (!val) {
+			if (sk->sk_state != TCP_CLOSE) {
+				err = -EINVAL;
+				break;
+			}
+			tp->window_clamp = 0;
+		} else
+			tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
+						SOCK_MIN_RCVBUF / 2 : val;
+		break;
+
+	case TCP_QUICKACK:
+		if (!val) {
+			tp->ack.pingpong = 1;
+		} else {
+			tp->ack.pingpong = 0;
+			if ((1 << sk->sk_state) &
+			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
+			    tcp_ack_scheduled(tp)) {
+				tp->ack.pending |= TCP_ACK_PUSHED;
+				cleanup_rbuf(sk, 1);
+				if (!(val & 1))
+					tp->ack.pingpong = 1;
+			}
+		}
+		break;
+
+	default:
+		err = -ENOPROTOOPT;
+		break;
+	};
+	release_sock(sk);
+	return err;
+}
+
+/* Return information about state of tcp endpoint in API format. */
+void tcp_get_info(struct sock *sk, struct tcp_info *info)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 now = tcp_time_stamp;
+
+	memset(info, 0, sizeof(*info));
+
+	info->tcpi_state = sk->sk_state;
+	info->tcpi_ca_state = tp->ca_state;
+	info->tcpi_retransmits = tp->retransmits;
+	info->tcpi_probes = tp->probes_out;
+	info->tcpi_backoff = tp->backoff;
+
+	if (tp->rx_opt.tstamp_ok)
+		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
+	if (tp->rx_opt.sack_ok)
+		info->tcpi_options |= TCPI_OPT_SACK;
+	if (tp->rx_opt.wscale_ok) {
+		info->tcpi_options |= TCPI_OPT_WSCALE;
+		info->tcpi_snd_wscale = tp->rx_opt.snd_wscale;
+		info->tcpi_rcv_wscale = tp->rx_opt.rcv_wscale;
+	} 
+
+	if (tp->ecn_flags&TCP_ECN_OK)
+		info->tcpi_options |= TCPI_OPT_ECN;
+
+	info->tcpi_rto = jiffies_to_usecs(tp->rto);
+	info->tcpi_ato = jiffies_to_usecs(tp->ack.ato);
+	info->tcpi_snd_mss = tp->mss_cache_std;
+	info->tcpi_rcv_mss = tp->ack.rcv_mss;
+
+	info->tcpi_unacked = tp->packets_out;
+	info->tcpi_sacked = tp->sacked_out;
+	info->tcpi_lost = tp->lost_out;
+	info->tcpi_retrans = tp->retrans_out;
+	info->tcpi_fackets = tp->fackets_out;
+
+	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
+	info->tcpi_last_data_recv = jiffies_to_msecs(now - tp->ack.lrcvtime);
+	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);
+
+	info->tcpi_pmtu = tp->pmtu_cookie;
+	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
+	info->tcpi_rtt = jiffies_to_usecs(tp->srtt)>>3;
+	info->tcpi_rttvar = jiffies_to_usecs(tp->mdev)>>2;
+	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
+	info->tcpi_snd_cwnd = tp->snd_cwnd;
+	info->tcpi_advmss = tp->advmss;
+	info->tcpi_reordering = tp->reordering;
+
+	info->tcpi_rcv_rtt = jiffies_to_usecs(tp->rcv_rtt_est.rtt)>>3;
+	info->tcpi_rcv_space = tp->rcvq_space.space;
+
+	info->tcpi_total_retrans = tp->total_retrans;
+}
+
+EXPORT_SYMBOL_GPL(tcp_get_info);
+
+int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
+		   int __user *optlen)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	int val, len;
+
+	if (level != SOL_TCP)
+		return tp->af_specific->getsockopt(sk, level, optname,
+						   optval, optlen);
+
+	if (get_user(len, optlen))
+		return -EFAULT;
+
+	len = min_t(unsigned int, len, sizeof(int));
+
+	if (len < 0)
+		return -EINVAL;
+
+	switch (optname) {
+	case TCP_MAXSEG:
+		val = tp->mss_cache_std;
+		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
+			val = tp->rx_opt.user_mss;
+		break;
+	case TCP_NODELAY:
+		val = !!(tp->nonagle&TCP_NAGLE_OFF);
+		break;
+	case TCP_CORK:
+		val = !!(tp->nonagle&TCP_NAGLE_CORK);
+		break;
+	case TCP_KEEPIDLE:
+		val = (tp->keepalive_time ? : sysctl_tcp_keepalive_time) / HZ;
+		break;
+	case TCP_KEEPINTVL:
+		val = (tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl) / HZ;
+		break;
+	case TCP_KEEPCNT:
+		val = tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
+		break;
+	case TCP_SYNCNT:
+		val = tp->syn_retries ? : sysctl_tcp_syn_retries;
+		break;
+	case TCP_LINGER2:
+		val = tp->linger2;
+		if (val >= 0)
+			val = (val ? : sysctl_tcp_fin_timeout) / HZ;
+		break;
+	case TCP_DEFER_ACCEPT:
+		val = !tp->defer_accept ? 0 : ((TCP_TIMEOUT_INIT / HZ) <<
+					       (tp->defer_accept - 1));
+		break;
+	case TCP_WINDOW_CLAMP:
+		val = tp->window_clamp;
+		break;
+	case TCP_INFO: {
+		struct tcp_info info;
+
+		if (get_user(len, optlen))
+			return -EFAULT;
+
+		tcp_get_info(sk, &info);
+
+		len = min_t(unsigned int, len, sizeof(info));
+		if (put_user(len, optlen))
+			return -EFAULT;
+		if (copy_to_user(optval, &info, len))
+			return -EFAULT;
+		return 0;
+	}
+	case TCP_QUICKACK:
+		val = !tp->ack.pingpong;
+		break;
+	default:
+		return -ENOPROTOOPT;
+	};
+
+	if (put_user(len, optlen))
+		return -EFAULT;
+	if (copy_to_user(optval, &val, len))
+		return -EFAULT;
+	return 0;
+}
+
+
+extern void __skb_cb_too_small_for_tcp(int, int);
+extern void tcpdiag_init(void);
+
+static __initdata unsigned long thash_entries;
+static int __init set_thash_entries(char *str)
+{
+	if (!str)
+		return 0;
+	thash_entries = simple_strtoul(str, &str, 0);
+	return 1;
+}
+__setup("thash_entries=", set_thash_entries);
+
+void __init tcp_init(void)
+{
+	struct sk_buff *skb = NULL;
+	int order, i;
+
+	if (sizeof(struct tcp_skb_cb) > sizeof(skb->cb))
+		__skb_cb_too_small_for_tcp(sizeof(struct tcp_skb_cb),
+					   sizeof(skb->cb));
+
+	tcp_openreq_cachep = kmem_cache_create("tcp_open_request",
+						   sizeof(struct open_request),
+					       0, SLAB_HWCACHE_ALIGN,
+					       NULL, NULL);
+	if (!tcp_openreq_cachep)
+		panic("tcp_init: Cannot alloc open_request cache.");
+
+	tcp_bucket_cachep = kmem_cache_create("tcp_bind_bucket",
+					      sizeof(struct tcp_bind_bucket),
+					      0, SLAB_HWCACHE_ALIGN,
+					      NULL, NULL);
+	if (!tcp_bucket_cachep)
+		panic("tcp_init: Cannot alloc tcp_bind_bucket cache.");
+
+	tcp_timewait_cachep = kmem_cache_create("tcp_tw_bucket",
+						sizeof(struct tcp_tw_bucket),
+						0, SLAB_HWCACHE_ALIGN,
+						NULL, NULL);
+	if (!tcp_timewait_cachep)
+		panic("tcp_init: Cannot alloc tcp_tw_bucket cache.");
+
+	/* Size and allocate the main established and bind bucket
+	 * hash tables.
+	 *
+	 * The methodology is similar to that of the buffer cache.
+	 */
+	tcp_ehash = (struct tcp_ehash_bucket *)
+		alloc_large_system_hash("TCP established",
+					sizeof(struct tcp_ehash_bucket),
+					thash_entries,
+					(num_physpages >= 128 * 1024) ?
+						(25 - PAGE_SHIFT) :
+						(27 - PAGE_SHIFT),
+					HASH_HIGHMEM,
+					&tcp_ehash_size,
+					NULL,
+					0);
+	tcp_ehash_size = (1 << tcp_ehash_size) >> 1;
+	for (i = 0; i < (tcp_ehash_size << 1); i++) {
+		rwlock_init(&tcp_ehash[i].lock);
+		INIT_HLIST_HEAD(&tcp_ehash[i].chain);
+	}
+
+	tcp_bhash = (struct tcp_bind_hashbucket *)
+		alloc_large_system_hash("TCP bind",
+					sizeof(struct tcp_bind_hashbucket),
+					tcp_ehash_size,
+					(num_physpages >= 128 * 1024) ?
+						(25 - PAGE_SHIFT) :
+						(27 - PAGE_SHIFT),
+					HASH_HIGHMEM,
+					&tcp_bhash_size,
+					NULL,
+					64 * 1024);
+	tcp_bhash_size = 1 << tcp_bhash_size;
+	for (i = 0; i < tcp_bhash_size; i++) {
+		spin_lock_init(&tcp_bhash[i].lock);
+		INIT_HLIST_HEAD(&tcp_bhash[i].chain);
+	}
+
+	/* Try to be a bit smarter and adjust defaults depending
+	 * on available memory.
+	 */
+	for (order = 0; ((1 << order) << PAGE_SHIFT) <
+			(tcp_bhash_size * sizeof(struct tcp_bind_hashbucket));
+			order++)
+		;
+	if (order > 4) {
+		sysctl_local_port_range[0] = 32768;
+		sysctl_local_port_range[1] = 61000;
+		sysctl_tcp_max_tw_buckets = 180000;
+		sysctl_tcp_max_orphans = 4096 << (order - 4);
+		sysctl_max_syn_backlog = 1024;
+	} else if (order < 3) {
+		sysctl_local_port_range[0] = 1024 * (3 - order);
+		sysctl_tcp_max_tw_buckets >>= (3 - order);
+		sysctl_tcp_max_orphans >>= (3 - order);
+		sysctl_max_syn_backlog = 128;
+	}
+	tcp_port_rover = sysctl_local_port_range[0] - 1;
+
+	sysctl_tcp_mem[0] =  768 << order;
+	sysctl_tcp_mem[1] = 1024 << order;
+	sysctl_tcp_mem[2] = 1536 << order;
+
+	if (order < 3) {
+		sysctl_tcp_wmem[2] = 64 * 1024;
+		sysctl_tcp_rmem[0] = PAGE_SIZE;
+		sysctl_tcp_rmem[1] = 43689;
+		sysctl_tcp_rmem[2] = 2 * 43689;
+	}
+
+	printk(KERN_INFO "TCP: Hash tables configured "
+	       "(established %d bind %d)\n",
+	       tcp_ehash_size << 1, tcp_bhash_size);
+}
+
+EXPORT_SYMBOL(tcp_accept);
+EXPORT_SYMBOL(tcp_close);
+EXPORT_SYMBOL(tcp_destroy_sock);
+EXPORT_SYMBOL(tcp_disconnect);
+EXPORT_SYMBOL(tcp_getsockopt);
+EXPORT_SYMBOL(tcp_ioctl);
+EXPORT_SYMBOL(tcp_openreq_cachep);
+EXPORT_SYMBOL(tcp_poll);
+EXPORT_SYMBOL(tcp_read_sock);
+EXPORT_SYMBOL(tcp_recvmsg);
+EXPORT_SYMBOL(tcp_sendmsg);
+EXPORT_SYMBOL(tcp_sendpage);
+EXPORT_SYMBOL(tcp_setsockopt);
+EXPORT_SYMBOL(tcp_shutdown);
+EXPORT_SYMBOL(tcp_statistics);
+EXPORT_SYMBOL(tcp_timewait_cachep);