tcp.c 88.8 KB
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/*
 * 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).
 *
8
 * Authors:	Ross Biro
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 *		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
 */

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#define pr_fmt(fmt) "TCP: " fmt

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#include <crypto/hash.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
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#include <linux/inet_diag.h>
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#include <linux/init.h>
#include <linux/fs.h>
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#include <linux/skbuff.h>
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#include <linux/scatterlist.h>
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#include <linux/splice.h>
#include <linux/net.h>
#include <linux/socket.h>
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#include <linux/random.h>
#include <linux/bootmem.h>
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#include <linux/highmem.h>
#include <linux/swap.h>
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#include <linux/cache.h>
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#include <linux/err.h>
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#include <linux/time.h>
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#include <linux/slab.h>
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#include <net/icmp.h>
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#include <net/inet_common.h>
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#include <net/tcp.h>
#include <net/xfrm.h>
#include <net/ip.h>
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#include <net/sock.h>
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#include <linux/uaccess.h>
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#include <asm/ioctls.h>
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#include <net/busy_poll.h>
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int sysctl_tcp_min_tso_segs __read_mostly = 2;

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int sysctl_tcp_autocorking __read_mostly = 1;

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struct percpu_counter tcp_orphan_count;
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EXPORT_SYMBOL_GPL(tcp_orphan_count);

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long sysctl_tcp_mem[3] __read_mostly;
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int sysctl_tcp_wmem[3] __read_mostly;
int sysctl_tcp_rmem[3] __read_mostly;
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EXPORT_SYMBOL(sysctl_tcp_mem);
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EXPORT_SYMBOL(sysctl_tcp_rmem);
EXPORT_SYMBOL(sysctl_tcp_wmem);

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atomic_long_t tcp_memory_allocated;	/* Current allocated memory. */
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EXPORT_SYMBOL(tcp_memory_allocated);
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/*
 * Current number of TCP sockets.
 */
struct percpu_counter tcp_sockets_allocated;
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EXPORT_SYMBOL(tcp_sockets_allocated);

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/*
 * TCP splice context
 */
struct tcp_splice_state {
	struct pipe_inode_info *pipe;
	size_t len;
	unsigned int flags;
};

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/*
 * Pressure flag: try to collapse.
 * Technical note: it is used by multiple contexts non atomically.
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 * All the __sk_mem_schedule() is of this nature: accounting
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 * is strict, actions are advisory and have some latency.
 */
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int tcp_memory_pressure __read_mostly;
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EXPORT_SYMBOL(tcp_memory_pressure);

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void tcp_enter_memory_pressure(struct sock *sk)
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{
	if (!tcp_memory_pressure) {
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		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
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		tcp_memory_pressure = 1;
	}
}
EXPORT_SYMBOL(tcp_enter_memory_pressure);

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/* Convert seconds to retransmits based on initial and max timeout */
static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
{
	u8 res = 0;

	if (seconds > 0) {
		int period = timeout;

		res = 1;
		while (seconds > period && res < 255) {
			res++;
			timeout <<= 1;
			if (timeout > rto_max)
				timeout = rto_max;
			period += timeout;
		}
	}
	return res;
}

/* Convert retransmits to seconds based on initial and max timeout */
static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
{
	int period = 0;

	if (retrans > 0) {
		period = timeout;
		while (--retrans) {
			timeout <<= 1;
			if (timeout > rto_max)
				timeout = rto_max;
			period += timeout;
		}
	}
	return period;
}

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/* Address-family independent initialization for a tcp_sock.
 *
 * NOTE: A lot of things set to zero explicitly by call to
 *       sk_alloc() so need not be done here.
 */
void tcp_init_sock(struct sock *sk)
{
	struct inet_connection_sock *icsk = inet_csk(sk);
	struct tcp_sock *tp = tcp_sk(sk);

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	tp->out_of_order_queue = RB_ROOT;
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	tcp_init_xmit_timers(sk);
	tcp_prequeue_init(tp);
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	INIT_LIST_HEAD(&tp->tsq_node);
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	icsk->icsk_rto = TCP_TIMEOUT_INIT;
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	tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
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	minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U);
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	/* 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 = TCP_INIT_CWND;

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	/* There's a bubble in the pipe until at least the first ACK. */
	tp->app_limited = ~0U;

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	/* See draft-stevens-tcpca-spec-01 for discussion of the
	 * initialization of these values.
	 */
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
	tp->snd_cwnd_clamp = ~0;
	tp->mss_cache = TCP_MSS_DEFAULT;

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	tp->reordering = sock_net(sk)->ipv4.sysctl_tcp_reordering;
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	tcp_assign_congestion_control(sk);
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	tp->tsoffset = 0;

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	sk->sk_state = TCP_CLOSE;

	sk->sk_write_space = sk_stream_write_space;
	sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);

	icsk->icsk_sync_mss = tcp_sync_mss;

	sk->sk_sndbuf = sysctl_tcp_wmem[1];
	sk->sk_rcvbuf = sysctl_tcp_rmem[1];

	sk_sockets_allocated_inc(sk);
}
EXPORT_SYMBOL(tcp_init_sock);

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static void tcp_tx_timestamp(struct sock *sk, u16 tsflags, struct sk_buff *skb)
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{
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	if (tsflags && skb) {
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		struct skb_shared_info *shinfo = skb_shinfo(skb);
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		struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
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		sock_tx_timestamp(sk, tsflags, &shinfo->tx_flags);
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		if (tsflags & SOF_TIMESTAMPING_TX_ACK)
			tcb->txstamp_ack = 1;
		if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
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			shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1;
	}
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}

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/*
 *	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;
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	const struct tcp_sock *tp = tcp_sk(sk);
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	int state;
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	sock_rps_record_flow(sk);

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	sock_poll_wait(file, sk_sleep(sk), wait);
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	state = sk_state_load(sk);
	if (state == TCP_LISTEN)
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		return inet_csk_listen_poll(sk);
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	/* Socket is not locked. We are protected from async events
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	 * by poll logic and correct handling of state changes
	 * made by other threads is impossible in any case.
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	 */

	mask = 0;

	/*
	 * 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
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	 * solve this dilemma. I would prefer, if POLLHUP were maskable,
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	 * then we could set it on SND_SHUTDOWN. BTW examples given
	 * in Stevens' books assume exactly this behaviour, it explains
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	 * why POLLHUP is incompatible with POLLOUT.	--ANK
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	 *
	 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
	 * blocking on fresh not-connected or disconnected socket. --ANK
	 */
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	if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
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		mask |= POLLHUP;
	if (sk->sk_shutdown & RCV_SHUTDOWN)
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		mask |= POLLIN | POLLRDNORM | POLLRDHUP;
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	/* Connected or passive Fast Open socket? */
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	if (state != TCP_SYN_SENT &&
	    (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
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		int target = sock_rcvlowat(sk, 0, INT_MAX);

		if (tp->urg_seq == tp->copied_seq &&
		    !sock_flag(sk, SOCK_URGINLINE) &&
		    tp->urg_data)
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			target++;
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		if (tp->rcv_nxt - tp->copied_seq >= target)
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			mask |= POLLIN | POLLRDNORM;

		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
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			if (sk_stream_is_writeable(sk)) {
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				mask |= POLLOUT | POLLWRNORM;
			} else {  /* send SIGIO later */
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				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
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				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);

				/* Race breaker. If space is freed after
				 * wspace test but before the flags are set,
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				 * IO signal will be lost. Memory barrier
				 * pairs with the input side.
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				 */
527
				smp_mb__after_atomic();
528
				if (sk_stream_is_writeable(sk))
L
Linus Torvalds 已提交
529 530
					mask |= POLLOUT | POLLWRNORM;
			}
531 532
		} else
			mask |= POLLOUT | POLLWRNORM;
L
Linus Torvalds 已提交
533 534 535

		if (tp->urg_data & TCP_URG_VALID)
			mask |= POLLPRI;
536
	} else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
W
Wei Wang 已提交
537 538 539 540 541
		/* Active TCP fastopen socket with defer_connect
		 * Return POLLOUT so application can call write()
		 * in order for kernel to generate SYN+data
		 */
		mask |= POLLOUT | POLLWRNORM;
L
Linus Torvalds 已提交
542
	}
T
Tom Marshall 已提交
543 544
	/* This barrier is coupled with smp_wmb() in tcp_reset() */
	smp_rmb();
545
	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
T
Tom Marshall 已提交
546 547
		mask |= POLLERR;

L
Linus Torvalds 已提交
548 549
	return mask;
}
E
Eric Dumazet 已提交
550
EXPORT_SYMBOL(tcp_poll);
L
Linus Torvalds 已提交
551 552 553 554 555

int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
	struct tcp_sock *tp = tcp_sk(sk);
	int answ;
E
Eric Dumazet 已提交
556
	bool slow;
L
Linus Torvalds 已提交
557 558 559 560 561 562

	switch (cmd) {
	case SIOCINQ:
		if (sk->sk_state == TCP_LISTEN)
			return -EINVAL;

E
Eric Dumazet 已提交
563
		slow = lock_sock_fast(sk);
564
		answ = tcp_inq(sk);
E
Eric Dumazet 已提交
565
		unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
566 567 568 569 570 571 572 573 574 575 576 577 578
		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;
579 580 581 582 583 584 585 586 587
	case SIOCOUTQNSD:
		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_nxt;
		break;
L
Linus Torvalds 已提交
588 589
	default:
		return -ENOIOCTLCMD;
590
	}
L
Linus Torvalds 已提交
591 592 593

	return put_user(answ, (int __user *)arg);
}
E
Eric Dumazet 已提交
594
EXPORT_SYMBOL(tcp_ioctl);
L
Linus Torvalds 已提交
595 596 597

static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
{
E
Eric Dumazet 已提交
598
	TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
L
Linus Torvalds 已提交
599 600 601
	tp->pushed_seq = tp->write_seq;
}

E
Eric Dumazet 已提交
602
static inline bool forced_push(const struct tcp_sock *tp)
L
Linus Torvalds 已提交
603 604 605 606
{
	return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
}

607
static void skb_entail(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
608
{
609
	struct tcp_sock *tp = tcp_sk(sk);
610 611 612 613
	struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);

	skb->csum    = 0;
	tcb->seq     = tcb->end_seq = tp->write_seq;
E
Eric Dumazet 已提交
614
	tcb->tcp_flags = TCPHDR_ACK;
615
	tcb->sacked  = 0;
616
	__skb_header_release(skb);
617
	tcp_add_write_queue_tail(sk, skb);
618 619
	sk->sk_wmem_queued += skb->truesize;
	sk_mem_charge(sk, skb->truesize);
620
	if (tp->nonagle & TCP_NAGLE_PUSH)
621
		tp->nonagle &= ~TCP_NAGLE_PUSH;
622 623

	tcp_slow_start_after_idle_check(sk);
L
Linus Torvalds 已提交
624 625
}

626
static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
L
Linus Torvalds 已提交
627
{
I
Ilpo Järvinen 已提交
628
	if (flags & MSG_OOB)
L
Linus Torvalds 已提交
629 630 631
		tp->snd_up = tp->write_seq;
}

E
Eric Dumazet 已提交
632
/* If a not yet filled skb is pushed, do not send it if
633
 * we have data packets in Qdisc or NIC queues :
E
Eric Dumazet 已提交
634 635 636 637
 * Because TX completion will happen shortly, it gives a chance
 * to coalesce future sendmsg() payload into this skb, without
 * need for a timer, and with no latency trade off.
 * As packets containing data payload have a bigger truesize
638 639 640
 * than pure acks (dataless) packets, the last checks prevent
 * autocorking if we only have an ACK in Qdisc/NIC queues,
 * or if TX completion was delayed after we processed ACK packet.
E
Eric Dumazet 已提交
641 642 643
 */
static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
				int size_goal)
L
Linus Torvalds 已提交
644
{
E
Eric Dumazet 已提交
645 646
	return skb->len < size_goal &&
	       sysctl_tcp_autocorking &&
647
	       skb != tcp_write_queue_head(sk) &&
E
Eric Dumazet 已提交
648 649 650 651 652 653 654 655
	       atomic_read(&sk->sk_wmem_alloc) > skb->truesize;
}

static void tcp_push(struct sock *sk, int flags, int mss_now,
		     int nonagle, int size_goal)
{
	struct tcp_sock *tp = tcp_sk(sk);
	struct sk_buff *skb;
656

E
Eric Dumazet 已提交
657 658
	if (!tcp_send_head(sk))
		return;
659

E
Eric Dumazet 已提交
660 661 662 663 664 665 666 667 668
	skb = tcp_write_queue_tail(sk);
	if (!(flags & MSG_MORE) || forced_push(tp))
		tcp_mark_push(tp, skb);

	tcp_mark_urg(tp, flags);

	if (tcp_should_autocork(sk, skb, size_goal)) {

		/* avoid atomic op if TSQ_THROTTLED bit is already set */
669
		if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
E
Eric Dumazet 已提交
670
			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
671
			set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
E
Eric Dumazet 已提交
672
		}
673 674 675 676 677
		/* It is possible TX completion already happened
		 * before we set TSQ_THROTTLED.
		 */
		if (atomic_read(&sk->sk_wmem_alloc) > skb->truesize)
			return;
L
Linus Torvalds 已提交
678
	}
E
Eric Dumazet 已提交
679 680 681 682 683

	if (flags & MSG_MORE)
		nonagle = TCP_NAGLE_CORK;

	__tcp_push_pending_frames(sk, mss_now, nonagle);
L
Linus Torvalds 已提交
684 685
}

686 687
static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
				unsigned int offset, size_t len)
J
Jens Axboe 已提交
688 689
{
	struct tcp_splice_state *tss = rd_desc->arg.data;
690
	int ret;
J
Jens Axboe 已提交
691

692
	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
A
Al Viro 已提交
693
			      min(rd_desc->count, len), tss->flags);
694 695 696
	if (ret > 0)
		rd_desc->count -= ret;
	return ret;
J
Jens Axboe 已提交
697 698 699 700 701 702 703
}

static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
{
	/* Store TCP splice context information in read_descriptor_t. */
	read_descriptor_t rd_desc = {
		.arg.data = tss,
704
		.count	  = tss->len,
J
Jens Axboe 已提交
705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735
	};

	return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
}

/**
 *  tcp_splice_read - splice data from TCP socket to a pipe
 * @sock:	socket to splice from
 * @ppos:	position (not valid)
 * @pipe:	pipe to splice to
 * @len:	number of bytes to splice
 * @flags:	splice modifier flags
 *
 * Description:
 *    Will read pages from given socket and fill them into a pipe.
 *
 **/
ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
			struct pipe_inode_info *pipe, size_t len,
			unsigned int flags)
{
	struct sock *sk = sock->sk;
	struct tcp_splice_state tss = {
		.pipe = pipe,
		.len = len,
		.flags = flags,
	};
	long timeo;
	ssize_t spliced;
	int ret;

736
	sock_rps_record_flow(sk);
J
Jens Axboe 已提交
737 738 739 740 741 742 743 744 745 746
	/*
	 * We can't seek on a socket input
	 */
	if (unlikely(*ppos))
		return -ESPIPE;

	ret = spliced = 0;

	lock_sock(sk);

747
	timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
J
Jens Axboe 已提交
748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775
	while (tss.len) {
		ret = __tcp_splice_read(sk, &tss);
		if (ret < 0)
			break;
		else if (!ret) {
			if (spliced)
				break;
			if (sock_flag(sk, SOCK_DONE))
				break;
			if (sk->sk_err) {
				ret = sock_error(sk);
				break;
			}
			if (sk->sk_shutdown & RCV_SHUTDOWN)
				break;
			if (sk->sk_state == TCP_CLOSE) {
				/*
				 * This occurs when user tries to read
				 * from never connected socket.
				 */
				if (!sock_flag(sk, SOCK_DONE))
					ret = -ENOTCONN;
				break;
			}
			if (!timeo) {
				ret = -EAGAIN;
				break;
			}
776 777 778 779 780 781
			/* if __tcp_splice_read() got nothing while we have
			 * an skb in receive queue, we do not want to loop.
			 * This might happen with URG data.
			 */
			if (!skb_queue_empty(&sk->sk_receive_queue))
				break;
782
			sk_wait_data(sk, &timeo, NULL);
J
Jens Axboe 已提交
783 784 785 786 787 788 789 790 791
			if (signal_pending(current)) {
				ret = sock_intr_errno(timeo);
				break;
			}
			continue;
		}
		tss.len -= ret;
		spliced += ret;

792 793
		if (!timeo)
			break;
J
Jens Axboe 已提交
794 795 796 797
		release_sock(sk);
		lock_sock(sk);

		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
798
		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
J
Jens Axboe 已提交
799 800 801 802 803 804 805 806 807 808 809
		    signal_pending(current))
			break;
	}

	release_sock(sk);

	if (spliced)
		return spliced;

	return ret;
}
E
Eric Dumazet 已提交
810
EXPORT_SYMBOL(tcp_splice_read);
J
Jens Axboe 已提交
811

812 813
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
				    bool force_schedule)
814 815 816 817 818 819
{
	struct sk_buff *skb;

	/* The TCP header must be at least 32-bit aligned.  */
	size = ALIGN(size, 4);

820 821 822
	if (unlikely(tcp_under_memory_pressure(sk)))
		sk_mem_reclaim_partial(sk);

823
	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
824
	if (likely(skb)) {
825
		bool mem_scheduled;
826

827 828
		if (force_schedule) {
			mem_scheduled = true;
829 830
			sk_forced_mem_schedule(sk, skb->truesize);
		} else {
831
			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
832
		}
833
		if (likely(mem_scheduled)) {
834
			skb_reserve(skb, sk->sk_prot->max_header);
835 836 837 838
			/*
			 * Make sure that we have exactly size bytes
			 * available to the caller, no more, no less.
			 */
E
Eric Dumazet 已提交
839
			skb->reserved_tailroom = skb->end - skb->tail - size;
840 841 842 843
			return skb;
		}
		__kfree_skb(skb);
	} else {
844
		sk->sk_prot->enter_memory_pressure(sk);
845 846 847 848 849
		sk_stream_moderate_sndbuf(sk);
	}
	return NULL;
}

I
Ilpo Järvinen 已提交
850 851 852 853
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
				       int large_allowed)
{
	struct tcp_sock *tp = tcp_sk(sk);
854
	u32 new_size_goal, size_goal;
E
Eric Dumazet 已提交
855 856 857 858

	if (!large_allowed || !sk_can_gso(sk))
		return mss_now;

859 860
	/* Note : tcp_tso_autosize() will eventually split this later */
	new_size_goal = sk->sk_gso_max_size - 1 - MAX_TCP_HEADER;
E
Eric Dumazet 已提交
861 862 863 864 865 866 867 868 869
	new_size_goal = tcp_bound_to_half_wnd(tp, new_size_goal);

	/* We try hard to avoid divides here */
	size_goal = tp->gso_segs * mss_now;
	if (unlikely(new_size_goal < size_goal ||
		     new_size_goal >= size_goal + mss_now)) {
		tp->gso_segs = min_t(u16, new_size_goal / mss_now,
				     sk->sk_gso_max_segs);
		size_goal = tp->gso_segs * mss_now;
I
Ilpo Järvinen 已提交
870 871
	}

E
Eric Dumazet 已提交
872
	return max(size_goal, mss_now);
I
Ilpo Järvinen 已提交
873 874 875 876 877 878 879 880 881 882 883 884
}

static int tcp_send_mss(struct sock *sk, int *size_goal, int flags)
{
	int mss_now;

	mss_now = tcp_current_mss(sk);
	*size_goal = tcp_xmit_size_goal(sk, mss_now, !(flags & MSG_OOB));

	return mss_now;
}

885 886
static ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
				size_t size, int flags)
L
Linus Torvalds 已提交
887 888
{
	struct tcp_sock *tp = tcp_sk(sk);
889
	int mss_now, size_goal;
L
Linus Torvalds 已提交
890 891 892 893
	int err;
	ssize_t copied;
	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

894 895 896 897 898 899
	/* Wait for a connection to finish. One exception is TCP Fast Open
	 * (passive side) where data is allowed to be sent before a connection
	 * is fully established.
	 */
	if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
	    !tcp_passive_fastopen(sk)) {
900 901
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
902
			goto out_err;
903
	}
L
Linus Torvalds 已提交
904

905
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
906

I
Ilpo Järvinen 已提交
907
	mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
908 909 910 911
	copied = 0;

	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
912
		goto out_err;
L
Linus Torvalds 已提交
913

914
	while (size > 0) {
915
		struct sk_buff *skb = tcp_write_queue_tail(sk);
916 917
		int copy, i;
		bool can_coalesce;
L
Linus Torvalds 已提交
918

919 920
		if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0 ||
		    !tcp_skb_can_collapse_to(skb)) {
L
Linus Torvalds 已提交
921 922 923 924
new_segment:
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;

925 926
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
						  skb_queue_empty(&sk->sk_write_queue));
L
Linus Torvalds 已提交
927 928 929
			if (!skb)
				goto wait_for_memory;

930
			skb_entail(sk, skb);
931
			copy = size_goal;
L
Linus Torvalds 已提交
932 933 934 935 936 937 938
		}

		if (copy > size)
			copy = size;

		i = skb_shinfo(skb)->nr_frags;
		can_coalesce = skb_can_coalesce(skb, i, page, offset);
H
Hans Westgaard Ry 已提交
939
		if (!can_coalesce && i >= sysctl_max_skb_frags) {
L
Linus Torvalds 已提交
940 941 942
			tcp_mark_push(tp, skb);
			goto new_segment;
		}
943
		if (!sk_wmem_schedule(sk, copy))
L
Linus Torvalds 已提交
944
			goto wait_for_memory;
945

L
Linus Torvalds 已提交
946
		if (can_coalesce) {
E
Eric Dumazet 已提交
947
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
L
Linus Torvalds 已提交
948 949 950 951
		} else {
			get_page(page);
			skb_fill_page_desc(skb, i, page, offset, copy);
		}
952
		skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
953

L
Linus Torvalds 已提交
954 955 956 957
		skb->len += copy;
		skb->data_len += copy;
		skb->truesize += copy;
		sk->sk_wmem_queued += copy;
958
		sk_mem_charge(sk, copy);
959
		skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
960 961
		tp->write_seq += copy;
		TCP_SKB_CB(skb)->end_seq += copy;
962
		tcp_skb_pcount_set(skb, 0);
L
Linus Torvalds 已提交
963 964

		if (!copied)
E
Eric Dumazet 已提交
965
			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
L
Linus Torvalds 已提交
966 967

		copied += copy;
968
		offset += copy;
969
		size -= copy;
970
		if (!size)
L
Linus Torvalds 已提交
971 972
			goto out;

973
		if (skb->len < size_goal || (flags & MSG_OOB))
L
Linus Torvalds 已提交
974 975 976 977
			continue;

		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
978
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
979
		} else if (skb == tcp_send_head(sk))
L
Linus Torvalds 已提交
980 981 982 983 984 985
			tcp_push_one(sk, mss_now);
		continue;

wait_for_sndbuf:
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
wait_for_memory:
E
Eric Dumazet 已提交
986 987
		tcp_push(sk, flags & ~MSG_MORE, mss_now,
			 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
988

989 990
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
991 992
			goto do_error;

I
Ilpo Järvinen 已提交
993
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
994 995 996
	}

out:
997 998 999 1000 1001
	if (copied) {
		tcp_tx_timestamp(sk, sk->sk_tsflags, tcp_write_queue_tail(sk));
		if (!(flags & MSG_SENDPAGE_NOTLAST))
			tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
	}
L
Linus Torvalds 已提交
1002 1003 1004 1005 1006 1007
	return copied;

do_error:
	if (copied)
		goto out;
out_err:
1008
	/* make sure we wake any epoll edge trigger waiter */
1009 1010
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1011
		sk->sk_write_space(sk);
1012 1013
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1014 1015 1016
	return sk_stream_error(sk, flags, err);
}

1017 1018
int tcp_sendpage(struct sock *sk, struct page *page, int offset,
		 size_t size, int flags)
L
Linus Torvalds 已提交
1019 1020 1021 1022
{
	ssize_t res;

	if (!(sk->sk_route_caps & NETIF_F_SG) ||
1023
	    !sk_check_csum_caps(sk))
1024 1025
		return sock_no_sendpage(sk->sk_socket, page, offset, size,
					flags);
L
Linus Torvalds 已提交
1026 1027

	lock_sock(sk);
1028 1029 1030

	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1031
	res = do_tcp_sendpages(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1032 1033 1034
	release_sock(sk);
	return res;
}
E
Eric Dumazet 已提交
1035
EXPORT_SYMBOL(tcp_sendpage);
L
Linus Torvalds 已提交
1036

1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054
/* Do not bother using a page frag for very small frames.
 * But use this heuristic only for the first skb in write queue.
 *
 * Having no payload in skb->head allows better SACK shifting
 * in tcp_shift_skb_data(), reducing sack/rack overhead, because
 * write queue has less skbs.
 * Each skb can hold up to MAX_SKB_FRAGS * 32Kbytes, or ~0.5 MB.
 * This also speeds up tso_fragment(), since it wont fallback
 * to tcp_fragment().
 */
static int linear_payload_sz(bool first_skb)
{
	if (first_skb)
		return SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER);
	return 0;
}

static int select_size(const struct sock *sk, bool sg, bool first_skb)
L
Linus Torvalds 已提交
1055
{
1056
	const struct tcp_sock *tp = tcp_sk(sk);
1057
	int tmp = tp->mss_cache;
L
Linus Torvalds 已提交
1058

K
Krishna Kumar 已提交
1059
	if (sg) {
1060
		if (sk_can_gso(sk)) {
1061
			tmp = linear_payload_sz(first_skb);
1062
		} else {
1063 1064 1065 1066 1067 1068 1069
			int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);

			if (tmp >= pgbreak &&
			    tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
				tmp = pgbreak;
		}
	}
L
Linus Torvalds 已提交
1070 1071 1072 1073

	return tmp;
}

1074 1075
void tcp_free_fastopen_req(struct tcp_sock *tp)
{
1076
	if (tp->fastopen_req) {
1077 1078 1079 1080 1081
		kfree(tp->fastopen_req);
		tp->fastopen_req = NULL;
	}
}

1082 1083
static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
				int *copied, size_t size)
1084 1085
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Wei Wang 已提交
1086
	struct inet_sock *inet = inet_sk(sk);
1087 1088 1089 1090
	int err, flags;

	if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE))
		return -EOPNOTSUPP;
1091
	if (tp->fastopen_req)
1092 1093 1094 1095
		return -EALREADY; /* Another Fast Open is in progress */

	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
				   sk->sk_allocation);
1096
	if (unlikely(!tp->fastopen_req))
1097 1098
		return -ENOBUFS;
	tp->fastopen_req->data = msg;
1099
	tp->fastopen_req->size = size;
1100

W
Wei Wang 已提交
1101 1102 1103 1104 1105 1106 1107 1108 1109
	if (inet->defer_connect) {
		err = tcp_connect(sk);
		/* Same failure procedure as in tcp_v4/6_connect */
		if (err) {
			tcp_set_state(sk, TCP_CLOSE);
			inet->inet_dport = 0;
			sk->sk_route_caps = 0;
		}
	}
1110 1111
	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
	err = __inet_stream_connect(sk->sk_socket, msg->msg_name,
1112
				    msg->msg_namelen, flags, 1);
1113 1114 1115 1116 1117 1118 1119 1120
	/* fastopen_req could already be freed in __inet_stream_connect
	 * if the connection times out or gets rst
	 */
	if (tp->fastopen_req) {
		*copied = tp->fastopen_req->copied;
		tcp_free_fastopen_req(tp);
		inet->defer_connect = 0;
	}
1121 1122 1123
	return err;
}

1124
int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
L
Linus Torvalds 已提交
1125 1126 1127
{
	struct tcp_sock *tp = tcp_sk(sk);
	struct sk_buff *skb;
1128
	struct sockcm_cookie sockc;
1129 1130
	int flags, err, copied = 0;
	int mss_now = 0, size_goal, copied_syn = 0;
1131
	bool process_backlog = false;
1132
	bool sg;
L
Linus Torvalds 已提交
1133 1134 1135 1136 1137
	long timeo;

	lock_sock(sk);

	flags = msg->msg_flags;
W
Wei Wang 已提交
1138
	if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect)) {
1139
		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1140 1141 1142 1143 1144 1145
		if (err == -EINPROGRESS && copied_syn > 0)
			goto out;
		else if (err)
			goto out_err;
	}

L
Linus Torvalds 已提交
1146 1147
	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

1148 1149
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1150 1151 1152 1153 1154 1155
	/* Wait for a connection to finish. One exception is TCP Fast Open
	 * (passive side) where data is allowed to be sent before a connection
	 * is fully established.
	 */
	if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
	    !tcp_passive_fastopen(sk)) {
1156 1157
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
1158
			goto do_error;
1159
	}
L
Linus Torvalds 已提交
1160

P
Pavel Emelyanov 已提交
1161 1162 1163
	if (unlikely(tp->repair)) {
		if (tp->repair_queue == TCP_RECV_QUEUE) {
			copied = tcp_send_rcvq(sk, msg, size);
1164
			goto out_nopush;
P
Pavel Emelyanov 已提交
1165 1166 1167 1168 1169 1170 1171 1172 1173
		}

		err = -EINVAL;
		if (tp->repair_queue == TCP_NO_QUEUE)
			goto out_err;

		/* 'common' sending to sendq */
	}

1174 1175 1176 1177 1178 1179 1180 1181 1182
	sockc.tsflags = sk->sk_tsflags;
	if (msg->msg_controllen) {
		err = sock_cmsg_send(sk, msg, &sockc);
		if (unlikely(err)) {
			err = -EINVAL;
			goto out_err;
		}
	}

L
Linus Torvalds 已提交
1183
	/* This should be in poll */
1184
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
1185 1186 1187 1188

	/* Ok commence sending. */
	copied = 0;

1189 1190 1191
restart:
	mss_now = tcp_send_mss(sk, &size_goal, flags);

L
Linus Torvalds 已提交
1192 1193
	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1194
		goto do_error;
L
Linus Torvalds 已提交
1195

1196
	sg = !!(sk->sk_route_caps & NETIF_F_SG);
K
Krishna Kumar 已提交
1197

A
Al Viro 已提交
1198
	while (msg_data_left(msg)) {
1199 1200
		int copy = 0;
		int max = size_goal;
L
Linus Torvalds 已提交
1201

1202 1203 1204 1205 1206
		skb = tcp_write_queue_tail(sk);
		if (tcp_send_head(sk)) {
			if (skb->ip_summed == CHECKSUM_NONE)
				max = mss_now;
			copy = max - skb->len;
1207
		}
L
Linus Torvalds 已提交
1208

1209
		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1210 1211
			bool first_skb;

L
Linus Torvalds 已提交
1212
new_segment:
1213 1214 1215 1216 1217
			/* Allocate new segment. If the interface is SG,
			 * allocate skb fitting to single page.
			 */
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;
L
Linus Torvalds 已提交
1218

1219 1220
			if (process_backlog && sk_flush_backlog(sk)) {
				process_backlog = false;
1221
				goto restart;
1222
			}
1223
			first_skb = skb_queue_empty(&sk->sk_write_queue);
1224
			skb = sk_stream_alloc_skb(sk,
1225
						  select_size(sk, sg, first_skb),
1226
						  sk->sk_allocation,
1227
						  first_skb);
1228 1229
			if (!skb)
				goto wait_for_memory;
L
Linus Torvalds 已提交
1230

1231
			process_backlog = true;
1232 1233 1234
			/*
			 * Check whether we can use HW checksum.
			 */
1235
			if (sk_check_csum_caps(sk))
1236
				skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1237

1238 1239 1240
			skb_entail(sk, skb);
			copy = size_goal;
			max = size_goal;
1241

1242 1243 1244 1245 1246 1247 1248
			/* All packets are restored as if they have
			 * already been sent. skb_mstamp isn't set to
			 * avoid wrong rtt estimation.
			 */
			if (tp->repair)
				TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED;
		}
L
Linus Torvalds 已提交
1249

1250
		/* Try to append data to the end of skb. */
A
Al Viro 已提交
1251 1252
		if (copy > msg_data_left(msg))
			copy = msg_data_left(msg);
1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267

		/* Where to copy to? */
		if (skb_availroom(skb) > 0) {
			/* We have some space in skb head. Superb! */
			copy = min_t(int, copy, skb_availroom(skb));
			err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy);
			if (err)
				goto do_fault;
		} else {
			bool merge = true;
			int i = skb_shinfo(skb)->nr_frags;
			struct page_frag *pfrag = sk_page_frag(sk);

			if (!sk_page_frag_refill(sk, pfrag))
				goto wait_for_memory;
1268

1269 1270
			if (!skb_can_coalesce(skb, i, pfrag->page,
					      pfrag->offset)) {
1271
				if (i >= sysctl_max_skb_frags || !sg) {
1272 1273
					tcp_mark_push(tp, skb);
					goto new_segment;
L
Linus Torvalds 已提交
1274
				}
1275
				merge = false;
L
Linus Torvalds 已提交
1276 1277
			}

1278 1279 1280 1281
			copy = min_t(int, copy, pfrag->size - pfrag->offset);

			if (!sk_wmem_schedule(sk, copy))
				goto wait_for_memory;
L
Linus Torvalds 已提交
1282

1283 1284 1285 1286 1287 1288
			err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
						       pfrag->page,
						       pfrag->offset,
						       copy);
			if (err)
				goto do_error;
L
Linus Torvalds 已提交
1289

1290 1291 1292 1293 1294 1295
			/* Update the skb. */
			if (merge) {
				skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
			} else {
				skb_fill_page_desc(skb, i, pfrag->page,
						   pfrag->offset, copy);
1296
				page_ref_inc(pfrag->page);
1297
			}
1298 1299 1300 1301 1302 1303 1304 1305 1306
			pfrag->offset += copy;
		}

		if (!copied)
			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;

		tp->write_seq += copy;
		TCP_SKB_CB(skb)->end_seq += copy;
		tcp_skb_pcount_set(skb, 0);
L
Linus Torvalds 已提交
1307

1308
		copied += copy;
A
Al Viro 已提交
1309
		if (!msg_data_left(msg)) {
1310 1311
			if (unlikely(flags & MSG_EOR))
				TCP_SKB_CB(skb)->eor = 1;
1312 1313
			goto out;
		}
L
Linus Torvalds 已提交
1314

1315
		if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
L
Linus Torvalds 已提交
1316 1317
			continue;

1318 1319 1320 1321 1322 1323 1324
		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
		} else if (skb == tcp_send_head(sk))
			tcp_push_one(sk, mss_now);
		continue;

L
Linus Torvalds 已提交
1325
wait_for_sndbuf:
1326
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
L
Linus Torvalds 已提交
1327
wait_for_memory:
1328 1329 1330
		if (copied)
			tcp_push(sk, flags & ~MSG_MORE, mss_now,
				 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1331

1332 1333
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
1334
			goto do_error;
L
Linus Torvalds 已提交
1335

1336
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1337 1338 1339
	}

out:
1340 1341
	if (copied) {
		tcp_tx_timestamp(sk, sockc.tsflags, tcp_write_queue_tail(sk));
E
Eric Dumazet 已提交
1342
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1343
	}
1344
out_nopush:
L
Linus Torvalds 已提交
1345
	release_sock(sk);
1346
	return copied + copied_syn;
L
Linus Torvalds 已提交
1347 1348 1349

do_fault:
	if (!skb->len) {
1350 1351 1352 1353 1354
		tcp_unlink_write_queue(skb, sk);
		/* It is the one place in all of TCP, except connection
		 * reset, where we can be unlinking the send_head.
		 */
		tcp_check_send_head(sk, skb);
1355
		sk_wmem_free_skb(sk, skb);
L
Linus Torvalds 已提交
1356 1357 1358
	}

do_error:
1359
	if (copied + copied_syn)
L
Linus Torvalds 已提交
1360 1361 1362
		goto out;
out_err:
	err = sk_stream_error(sk, flags, err);
1363
	/* make sure we wake any epoll edge trigger waiter */
1364 1365
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1366
		sk->sk_write_space(sk);
1367 1368
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1369 1370 1371
	release_sock(sk);
	return err;
}
E
Eric Dumazet 已提交
1372
EXPORT_SYMBOL(tcp_sendmsg);
L
Linus Torvalds 已提交
1373 1374 1375 1376 1377 1378

/*
 *	Handle reading urgent data. BSD has very simple semantics for
 *	this, no blocking and very strange errors 8)
 */

1379
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
L
Linus Torvalds 已提交
1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402
{
	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))
A
Al Viro 已提交
1403
				err = memcpy_to_msg(msg, &c, 1);
L
Linus Torvalds 已提交
1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422
			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;
}

P
Pavel Emelyanov 已提交
1423 1424 1425 1426 1427 1428 1429 1430
static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
{
	struct sk_buff *skb;
	int copied = 0, err = 0;

	/* XXX -- need to support SO_PEEK_OFF */

	skb_queue_walk(&sk->sk_write_queue, skb) {
1431
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
P
Pavel Emelyanov 已提交
1432 1433 1434 1435 1436 1437 1438 1439 1440
		if (err)
			break;

		copied += skb->len;
	}

	return err ?: copied;
}

L
Linus Torvalds 已提交
1441 1442 1443 1444 1445 1446
/* 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.
 */
1447
static void tcp_cleanup_rbuf(struct sock *sk, int copied)
L
Linus Torvalds 已提交
1448 1449
{
	struct tcp_sock *tp = tcp_sk(sk);
E
Eric Dumazet 已提交
1450
	bool time_to_ack = false;
L
Linus Torvalds 已提交
1451 1452 1453

	struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);

1454
	WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
J
Joe Perches 已提交
1455
	     "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1456
	     tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
L
Linus Torvalds 已提交
1457

1458 1459
	if (inet_csk_ack_scheduled(sk)) {
		const struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1460 1461
		   /* Delayed ACKs frequently hit locked sockets during bulk
		    * receive. */
1462
		if (icsk->icsk_ack.blocked ||
L
Linus Torvalds 已提交
1463
		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
1464
		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
L
Linus Torvalds 已提交
1465 1466 1467 1468 1469 1470
		    /*
		     * 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.
		     */
1471 1472 1473 1474 1475
		    (copied > 0 &&
		     ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
		      ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
		       !icsk->icsk_ack.pingpong)) &&
		      !atomic_read(&sk->sk_rmem_alloc)))
E
Eric Dumazet 已提交
1476
			time_to_ack = true;
L
Linus Torvalds 已提交
1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497
	}

	/* 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)
E
Eric Dumazet 已提交
1498
				time_to_ack = true;
L
Linus Torvalds 已提交
1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509
		}
	}
	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);

1510
	NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPPREQUEUED);
L
Linus Torvalds 已提交
1511 1512

	while ((skb = __skb_dequeue(&tp->ucopy.prequeue)) != NULL)
P
Peter Zijlstra 已提交
1513
		sk_backlog_rcv(sk, skb);
L
Linus Torvalds 已提交
1514 1515 1516 1517 1518

	/* Clear memory counter. */
	tp->ucopy.memory = 0;
}

1519
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
L
Linus Torvalds 已提交
1520 1521 1522 1523
{
	struct sk_buff *skb;
	u32 offset;

1524
	while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
L
Linus Torvalds 已提交
1525
		offset = seq - TCP_SKB_CB(skb)->seq;
1526 1527
		if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
			pr_err_once("%s: found a SYN, please report !\n", __func__);
L
Linus Torvalds 已提交
1528
			offset--;
1529
		}
1530
		if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
L
Linus Torvalds 已提交
1531 1532 1533
			*off = offset;
			return skb;
		}
1534 1535 1536 1537
		/* This looks weird, but this can happen if TCP collapsing
		 * splitted a fat GRO packet, while we released socket lock
		 * in skb_splice_bits()
		 */
D
Dan Williams 已提交
1538
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566
	}
	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) {
1567 1568
			int used;
			size_t len;
L
Linus Torvalds 已提交
1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579

			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);
1580
			if (used <= 0) {
1581 1582 1583 1584
				if (!copied)
					copied = used;
				break;
			} else if (used <= len) {
L
Linus Torvalds 已提交
1585 1586 1587 1588
				seq += used;
				copied += used;
				offset += used;
			}
1589
			/* If recv_actor drops the lock (e.g. TCP splice
1590 1591 1592 1593
			 * receive) the skb pointer might be invalid when
			 * getting here: tcp_collapse might have deleted it
			 * while aggregating skbs from the socket queue.
			 */
1594 1595
			skb = tcp_recv_skb(sk, seq - 1, &offset);
			if (!skb)
L
Linus Torvalds 已提交
1596
				break;
1597 1598 1599 1600 1601
			/* TCP coalescing might have appended data to the skb.
			 * Try to splice more frags
			 */
			if (offset + 1 != skb->len)
				continue;
L
Linus Torvalds 已提交
1602
		}
1603
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
D
Dan Williams 已提交
1604
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1605 1606 1607
			++seq;
			break;
		}
D
Dan Williams 已提交
1608
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1609 1610
		if (!desc->count)
			break;
1611
		tp->copied_seq = seq;
L
Linus Torvalds 已提交
1612 1613 1614 1615 1616 1617
	}
	tp->copied_seq = seq;

	tcp_rcv_space_adjust(sk);

	/* Clean up data we have read: This will do ACK frames. */
1618 1619
	if (copied > 0) {
		tcp_recv_skb(sk, seq, &offset);
1620
		tcp_cleanup_rbuf(sk, copied);
1621
	}
L
Linus Torvalds 已提交
1622 1623
	return copied;
}
E
Eric Dumazet 已提交
1624
EXPORT_SYMBOL(tcp_read_sock);
L
Linus Torvalds 已提交
1625

1626 1627 1628 1629 1630 1631
int tcp_peek_len(struct socket *sock)
{
	return tcp_inq(sock->sk);
}
EXPORT_SYMBOL(tcp_peek_len);

L
Linus Torvalds 已提交
1632 1633 1634 1635 1636 1637 1638 1639
/*
 *	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.
 */

1640 1641
int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
		int flags, int *addr_len)
L
Linus Torvalds 已提交
1642 1643 1644 1645 1646 1647 1648 1649 1650 1651
{
	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;
1652
	struct sk_buff *skb, *last;
I
Ilpo Järvinen 已提交
1653
	u32 urg_hole = 0;
L
Linus Torvalds 已提交
1654

1655
	if (unlikely(flags & MSG_ERRQUEUE))
1656
		return inet_recv_error(sk, msg, len, addr_len);
1657

1658 1659 1660
	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
	    (sk->sk_state == TCP_ESTABLISHED))
		sk_busy_loop(sk, nonblock);
1661

L
Linus Torvalds 已提交
1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673
	lock_sock(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;

P
Pavel Emelyanov 已提交
1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688
	if (unlikely(tp->repair)) {
		err = -EPERM;
		if (!(flags & MSG_PEEK))
			goto out;

		if (tp->repair_queue == TCP_SEND_QUEUE)
			goto recv_sndq;

		err = -EINVAL;
		if (tp->repair_queue == TCP_NO_QUEUE)
			goto out;

		/* 'common' recv queue MSG_PEEK-ing */
	}

L
Linus Torvalds 已提交
1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711
	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 {
		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. */

1712
		last = skb_peek_tail(&sk->sk_receive_queue);
1713
		skb_queue_walk(&sk->sk_receive_queue, skb) {
1714
			last = skb;
L
Linus Torvalds 已提交
1715 1716 1717
			/* Now that we have two receive queues this
			 * shouldn't happen.
			 */
1718
			if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
J
Joe Perches 已提交
1719 1720 1721
				 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
				 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
				 flags))
L
Linus Torvalds 已提交
1722
				break;
1723

L
Linus Torvalds 已提交
1724
			offset = *seq - TCP_SKB_CB(skb)->seq;
1725 1726
			if (unlikely(TCP_SKB_CB(skb)->tcp_flags & TCPHDR_SYN)) {
				pr_err_once("%s: found a SYN, please report !\n", __func__);
L
Linus Torvalds 已提交
1727
				offset--;
1728
			}
L
Linus Torvalds 已提交
1729 1730
			if (offset < skb->len)
				goto found_ok_skb;
1731
			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1732
				goto found_fin_ok;
J
Joe Perches 已提交
1733 1734 1735
			WARN(!(flags & MSG_PEEK),
			     "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
			     *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
1736
		}
L
Linus Torvalds 已提交
1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747

		/* 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 ||
1748
			    signal_pending(current))
L
Linus Torvalds 已提交
1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783
				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;
			}
		}

1784
		tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1785

1786
		if (!sysctl_tcp_low_latency && tp->ucopy.task == user_recv) {
L
Linus Torvalds 已提交
1787 1788 1789 1790
			/* Install new reader */
			if (!user_recv && !(flags & (MSG_TRUNC | MSG_PEEK))) {
				user_recv = current;
				tp->ucopy.task = user_recv;
1791
				tp->ucopy.msg = msg;
L
Linus Torvalds 已提交
1792 1793 1794 1795
			}

			tp->ucopy.len = len;

1796 1797
			WARN_ON(tp->copied_seq != tp->rcv_nxt &&
				!(flags & (MSG_PEEK | MSG_TRUNC)));
L
Linus Torvalds 已提交
1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824

			/* 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.
			 */
1825
			if (!skb_queue_empty(&tp->ucopy.prequeue))
L
Linus Torvalds 已提交
1826 1827 1828 1829 1830 1831 1832 1833 1834
				goto do_prequeue;

			/* __ Set realtime policy in scheduler __ */
		}

		if (copied >= target) {
			/* Do not sleep, just process backlog. */
			release_sock(sk);
			lock_sock(sk);
1835 1836 1837
		} else {
			sk_wait_data(sk, &timeo, last);
		}
L
Linus Torvalds 已提交
1838 1839 1840 1841 1842 1843

		if (user_recv) {
			int chunk;

			/* __ Restore normal policy in scheduler __ */

1844 1845
			chunk = len - tp->ucopy.len;
			if (chunk != 0) {
1846
				NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMBACKLOG, chunk);
L
Linus Torvalds 已提交
1847 1848 1849 1850 1851
				len -= chunk;
				copied += chunk;
			}

			if (tp->rcv_nxt == tp->copied_seq &&
1852
			    !skb_queue_empty(&tp->ucopy.prequeue)) {
L
Linus Torvalds 已提交
1853 1854 1855
do_prequeue:
				tcp_prequeue_process(sk);

1856 1857
				chunk = len - tp->ucopy.len;
				if (chunk != 0) {
1858
					NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
L
Linus Torvalds 已提交
1859 1860 1861 1862 1863
					len -= chunk;
					copied += chunk;
				}
			}
		}
I
Ilpo Järvinen 已提交
1864 1865
		if ((flags & MSG_PEEK) &&
		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
1866 1867 1868
			net_dbg_ratelimited("TCP(%s:%d): Application bug, race in MSG_PEEK\n",
					    current->comm,
					    task_pid_nr(current));
L
Linus Torvalds 已提交
1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885
			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;
I
Ilpo Järvinen 已提交
1886
						urg_hole++;
L
Linus Torvalds 已提交
1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897
						offset++;
						used--;
						if (!used)
							goto skip_copy;
					}
				} else
					used = urg_offset;
			}
		}

		if (!(flags & MSG_TRUNC)) {
1898
			err = skb_copy_datagram_msg(skb, offset, msg, used);
D
Dan Williams 已提交
1899 1900 1901 1902 1903
			if (err) {
				/* Exception. Bailout! */
				if (!copied)
					copied = -EFAULT;
				break;
L
Linus Torvalds 已提交
1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915
			}
		}

		*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;
1916
			tcp_fast_path_check(sk);
L
Linus Torvalds 已提交
1917 1918 1919 1920
		}
		if (used + offset < skb->len)
			continue;

1921
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1922
			goto found_fin_ok;
D
Dan Williams 已提交
1923 1924
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1925 1926 1927 1928 1929
		continue;

	found_fin_ok:
		/* Process the FIN. */
		++*seq;
D
Dan Williams 已提交
1930 1931
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1932 1933 1934 1935
		break;
	} while (len > 0);

	if (user_recv) {
1936
		if (!skb_queue_empty(&tp->ucopy.prequeue)) {
L
Linus Torvalds 已提交
1937 1938 1939 1940 1941 1942 1943
			int chunk;

			tp->ucopy.len = copied > 0 ? len : 0;

			tcp_prequeue_process(sk);

			if (copied > 0 && (chunk = len - tp->ucopy.len) != 0) {
1944
				NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPDIRECTCOPYFROMPREQUEUE, chunk);
L
Linus Torvalds 已提交
1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958
				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. */
1959
	tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1960 1961 1962 1963 1964 1965 1966 1967 1968

	release_sock(sk);
	return copied;

out:
	release_sock(sk);
	return err;

recv_urg:
1969
	err = tcp_recv_urg(sk, msg, len, flags);
L
Linus Torvalds 已提交
1970
	goto out;
P
Pavel Emelyanov 已提交
1971 1972 1973 1974

recv_sndq:
	err = tcp_peek_sndq(sk, msg, len);
	goto out;
L
Linus Torvalds 已提交
1975
}
E
Eric Dumazet 已提交
1976
EXPORT_SYMBOL(tcp_recvmsg);
L
Linus Torvalds 已提交
1977

I
Ilpo Järvinen 已提交
1978 1979 1980 1981 1982 1983 1984
void tcp_set_state(struct sock *sk, int state)
{
	int oldstate = sk->sk_state;

	switch (state) {
	case TCP_ESTABLISHED:
		if (oldstate != TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
1985
			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
1986 1987 1988 1989
		break;

	case TCP_CLOSE:
		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
1990
			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
I
Ilpo Järvinen 已提交
1991 1992 1993 1994

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1995
			inet_put_port(sk);
I
Ilpo Järvinen 已提交
1996 1997
		/* fall through */
	default:
1998
		if (oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
1999
			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2000 2001 2002 2003 2004
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
2005
	sk_state_store(sk, state);
I
Ilpo Järvinen 已提交
2006 2007

#ifdef STATE_TRACE
2008
	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
I
Ilpo Järvinen 已提交
2009 2010 2011 2012
#endif
}
EXPORT_SYMBOL_GPL(tcp_set_state);

L
Linus Torvalds 已提交
2013 2014 2015 2016 2017 2018 2019
/*
 *	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.
 */

2020
static const unsigned char new_state[16] = {
L
Linus Torvalds 已提交
2021
  /* current state:        new state:      action:	*/
2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034
  [0 /* (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,
  [TCP_NEW_SYN_RECV]	= TCP_CLOSE,	/* should not happen ! */
L
Linus Torvalds 已提交
2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048
};

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
2049
 *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
L
Linus Torvalds 已提交
2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069
 */

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);
	}
}
E
Eric Dumazet 已提交
2070
EXPORT_SYMBOL(tcp_shutdown);
L
Linus Torvalds 已提交
2071

A
Arun Sharma 已提交
2072 2073 2074 2075 2076 2077 2078
bool tcp_check_oom(struct sock *sk, int shift)
{
	bool too_many_orphans, out_of_socket_memory;

	too_many_orphans = tcp_too_many_orphans(sk, shift);
	out_of_socket_memory = tcp_out_of_memory(sk);

2079 2080 2081 2082
	if (too_many_orphans)
		net_info_ratelimited("too many orphaned sockets\n");
	if (out_of_socket_memory)
		net_info_ratelimited("out of memory -- consider tuning tcp_mem\n");
A
Arun Sharma 已提交
2083 2084 2085
	return too_many_orphans || out_of_socket_memory;
}

L
Linus Torvalds 已提交
2086 2087 2088 2089
void tcp_close(struct sock *sk, long timeout)
{
	struct sk_buff *skb;
	int data_was_unread = 0;
H
Herbert Xu 已提交
2090
	int state;
L
Linus Torvalds 已提交
2091 2092 2093 2094 2095 2096 2097 2098

	lock_sock(sk);
	sk->sk_shutdown = SHUTDOWN_MASK;

	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);

		/* Special case. */
2099
		inet_csk_listen_stop(sk);
L
Linus Torvalds 已提交
2100 2101 2102 2103 2104 2105 2106 2107 2108

		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) {
2109 2110 2111 2112
		u32 len = TCP_SKB_CB(skb)->end_seq - TCP_SKB_CB(skb)->seq;

		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
			len--;
L
Linus Torvalds 已提交
2113 2114 2115 2116
		data_was_unread += len;
		__kfree_skb(skb);
	}

2117
	sk_mem_reclaim(sk);
L
Linus Torvalds 已提交
2118

2119 2120 2121 2122
	/* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
	if (sk->sk_state == TCP_CLOSE)
		goto adjudge_to_death;

2123 2124 2125 2126 2127 2128
	/* As outlined in RFC 2525, section 2.17, 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.
L
Linus Torvalds 已提交
2129
	 */
P
Pavel Emelyanov 已提交
2130 2131 2132
	if (unlikely(tcp_sk(sk)->repair)) {
		sk->sk_prot->disconnect(sk, 0);
	} else if (data_was_unread) {
L
Linus Torvalds 已提交
2133
		/* Unread data was tossed, zap the connection. */
2134
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
L
Linus Torvalds 已提交
2135
		tcp_set_state(sk, TCP_CLOSE);
2136
		tcp_send_active_reset(sk, sk->sk_allocation);
L
Linus Torvalds 已提交
2137 2138 2139
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
2140
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
L
Linus Torvalds 已提交
2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165
	} 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
2166 2167 2168 2169
		 * XXX (TFO) - To start off we don't support SYN+ACK+FIN
		 * in a single packet! (May consider it later but will
		 * probably need API support or TCP_CORK SYN-ACK until
		 * data is written and socket is closed.)
L
Linus Torvalds 已提交
2170 2171 2172 2173 2174 2175 2176
		 */
		tcp_send_fin(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
H
Herbert Xu 已提交
2177 2178 2179 2180
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

L
Linus Torvalds 已提交
2181 2182 2183 2184 2185 2186 2187 2188 2189
	/* 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);
2190
	WARN_ON(sock_owned_by_user(sk));
L
Linus Torvalds 已提交
2191

H
Herbert Xu 已提交
2192 2193
	percpu_counter_inc(sk->sk_prot->orphan_count);

H
Herbert Xu 已提交
2194 2195 2196
	/* Have we already been destroyed by a softirq or backlog? */
	if (state != TCP_CLOSE && sk->sk_state == TCP_CLOSE)
		goto out;
L
Linus Torvalds 已提交
2197 2198 2199 2200

	/*	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.
2201
	 *	We use a 1 minute timeout (about the same as BSD) then kill
L
Linus Torvalds 已提交
2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216
	 *	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);
2217
			__NET_INC_STATS(sock_net(sk),
2218
					LINUX_MIB_TCPABORTONLINGER);
L
Linus Torvalds 已提交
2219
		} else {
2220
			const int tmo = tcp_fin_time(sk);
L
Linus Torvalds 已提交
2221 2222

			if (tmo > TCP_TIMEWAIT_LEN) {
2223 2224
				inet_csk_reset_keepalive_timer(sk,
						tmo - TCP_TIMEWAIT_LEN);
L
Linus Torvalds 已提交
2225 2226 2227 2228 2229 2230 2231
			} else {
				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
				goto out;
			}
		}
	}
	if (sk->sk_state != TCP_CLOSE) {
2232
		sk_mem_reclaim(sk);
A
Arun Sharma 已提交
2233
		if (tcp_check_oom(sk, 0)) {
L
Linus Torvalds 已提交
2234 2235
			tcp_set_state(sk, TCP_CLOSE);
			tcp_send_active_reset(sk, GFP_ATOMIC);
2236
			__NET_INC_STATS(sock_net(sk),
2237
					LINUX_MIB_TCPABORTONMEMORY);
L
Linus Torvalds 已提交
2238 2239 2240
		}
	}

2241 2242 2243 2244 2245 2246
	if (sk->sk_state == TCP_CLOSE) {
		struct request_sock *req = tcp_sk(sk)->fastopen_rsk;
		/* We could get here with a non-NULL req if the socket is
		 * aborted (e.g., closed with unread data) before 3WHS
		 * finishes.
		 */
2247
		if (req)
2248
			reqsk_fastopen_remove(sk, req, false);
2249
		inet_csk_destroy_sock(sk);
2250
	}
L
Linus Torvalds 已提交
2251 2252 2253 2254 2255 2256 2257
	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}
E
Eric Dumazet 已提交
2258
EXPORT_SYMBOL(tcp_close);
L
Linus Torvalds 已提交
2259 2260 2261

/* These states need RST on ABORT according to RFC793 */

E
Eric Dumazet 已提交
2262
static inline bool tcp_need_reset(int state)
L
Linus Torvalds 已提交
2263 2264 2265 2266 2267 2268 2269 2270 2271
{
	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);
2272
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2273 2274 2275 2276 2277 2278 2279 2280 2281
	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) {
2282
		inet_csk_listen_stop(sk);
P
Pavel Emelyanov 已提交
2283 2284
	} else if (unlikely(tp->repair)) {
		sk->sk_err = ECONNABORTED;
L
Linus Torvalds 已提交
2285 2286 2287
	} else if (tcp_need_reset(old_state) ||
		   (tp->snd_nxt != tp->write_seq &&
		    (1 << old_state) & (TCPF_CLOSING | TCPF_LAST_ACK))) {
S
Stephen Hemminger 已提交
2288
		/* The last check adjusts for discrepancy of Linux wrt. RFC
L
Linus Torvalds 已提交
2289 2290 2291 2292 2293 2294 2295 2296 2297
		 * 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);
2298
	tcp_write_queue_purge(sk);
2299
	tcp_fastopen_active_disable_ofo_check(sk);
2300
	skb_rbtree_purge(&tp->out_of_order_queue);
L
Linus Torvalds 已提交
2301

E
Eric Dumazet 已提交
2302
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
2303 2304 2305 2306 2307 2308

	if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
		inet_reset_saddr(sk);

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);
2309
	tp->srtt_us = 0;
2310 2311
	tp->write_seq += tp->max_window + 2;
	if (tp->write_seq == 0)
L
Linus Torvalds 已提交
2312
		tp->write_seq = 1;
2313
	icsk->icsk_backoff = 0;
L
Linus Torvalds 已提交
2314
	tp->snd_cwnd = 2;
2315
	icsk->icsk_probes_out = 0;
L
Linus Torvalds 已提交
2316
	tp->packets_out = 0;
I
Ilpo Järvinen 已提交
2317
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
L
Linus Torvalds 已提交
2318
	tp->snd_cwnd_cnt = 0;
2319
	tp->window_clamp = 0;
2320
	tcp_set_ca_state(sk, TCP_CA_Open);
L
Linus Torvalds 已提交
2321
	tcp_clear_retrans(tp);
2322
	inet_csk_delack_init(sk);
2323
	tcp_init_send_head(sk);
2324
	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
L
Linus Torvalds 已提交
2325
	__sk_dst_reset(sk);
2326
	tcp_saved_syn_free(tp);
L
Linus Torvalds 已提交
2327

2328 2329 2330 2331
	/* Clean up fastopen related fields */
	tcp_free_fastopen_req(tp);
	inet->defer_connect = 0;

E
Eric Dumazet 已提交
2332
	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
L
Linus Torvalds 已提交
2333 2334 2335 2336

	sk->sk_error_report(sk);
	return err;
}
E
Eric Dumazet 已提交
2337
EXPORT_SYMBOL(tcp_disconnect);
L
Linus Torvalds 已提交
2338

E
Eric Dumazet 已提交
2339
static inline bool tcp_can_repair_sock(const struct sock *sk)
P
Pavel Emelyanov 已提交
2340
{
2341
	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2342
		(sk->sk_state != TCP_LISTEN);
P
Pavel Emelyanov 已提交
2343 2344
}

2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376
static int tcp_repair_set_window(struct tcp_sock *tp, char __user *optbuf, int len)
{
	struct tcp_repair_window opt;

	if (!tp->repair)
		return -EPERM;

	if (len != sizeof(opt))
		return -EINVAL;

	if (copy_from_user(&opt, optbuf, sizeof(opt)))
		return -EFAULT;

	if (opt.max_window < opt.snd_wnd)
		return -EINVAL;

	if (after(opt.snd_wl1, tp->rcv_nxt + opt.rcv_wnd))
		return -EINVAL;

	if (after(opt.rcv_wup, tp->rcv_nxt))
		return -EINVAL;

	tp->snd_wl1	= opt.snd_wl1;
	tp->snd_wnd	= opt.snd_wnd;
	tp->max_window	= opt.max_window;

	tp->rcv_wnd	= opt.rcv_wnd;
	tp->rcv_wup	= opt.rcv_wup;

	return 0;
}

2377 2378
static int tcp_repair_options_est(struct tcp_sock *tp,
		struct tcp_repair_opt __user *optbuf, unsigned int len)
2379
{
2380
	struct tcp_repair_opt opt;
2381

2382 2383
	while (len >= sizeof(opt)) {
		if (copy_from_user(&opt, optbuf, sizeof(opt)))
2384 2385 2386
			return -EFAULT;

		optbuf++;
2387
		len -= sizeof(opt);
2388

2389 2390 2391
		switch (opt.opt_code) {
		case TCPOPT_MSS:
			tp->rx_opt.mss_clamp = opt.opt_val;
2392
			break;
2393
		case TCPOPT_WINDOW:
2394 2395 2396 2397
			{
				u16 snd_wscale = opt.opt_val & 0xFFFF;
				u16 rcv_wscale = opt.opt_val >> 16;

2398
				if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2399
					return -EFBIG;
2400

2401 2402 2403 2404
				tp->rx_opt.snd_wscale = snd_wscale;
				tp->rx_opt.rcv_wscale = rcv_wscale;
				tp->rx_opt.wscale_ok = 1;
			}
2405 2406
			break;
		case TCPOPT_SACK_PERM:
2407 2408 2409
			if (opt.opt_val != 0)
				return -EINVAL;

2410 2411 2412 2413 2414
			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
			if (sysctl_tcp_fack)
				tcp_enable_fack(tp);
			break;
		case TCPOPT_TIMESTAMP:
2415 2416 2417
			if (opt.opt_val != 0)
				return -EINVAL;

2418 2419 2420 2421 2422 2423 2424 2425
			tp->rx_opt.tstamp_ok = 1;
			break;
		}
	}

	return 0;
}

L
Linus Torvalds 已提交
2426 2427 2428
/*
 *	Socket option code for TCP.
 */
2429
static int do_tcp_setsockopt(struct sock *sk, int level,
2430
		int optname, char __user *optval, unsigned int optlen)
L
Linus Torvalds 已提交
2431 2432
{
	struct tcp_sock *tp = tcp_sk(sk);
2433
	struct inet_connection_sock *icsk = inet_csk(sk);
2434
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2435 2436 2437
	int val;
	int err = 0;

2438 2439 2440
	/* These are data/string values, all the others are ints */
	switch (optname) {
	case TCP_CONGESTION: {
2441 2442 2443 2444 2445 2446
		char name[TCP_CA_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
2447
					min_t(long, TCP_CA_NAME_MAX-1, optlen));
2448 2449 2450 2451 2452
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
2453
		err = tcp_set_congestion_control(sk, name);
2454 2455 2456
		release_sock(sk);
		return err;
	}
2457 2458 2459
	default:
		/* fallthru */
		break;
2460
	}
2461

L
Linus Torvalds 已提交
2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474
	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 */
2475
		if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
L
Linus Torvalds 已提交
2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492
			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;
2493
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2494 2495 2496 2497 2498
		} else {
			tp->nonagle &= ~TCP_NAGLE_OFF;
		}
		break;

A
Andreas Petlund 已提交
2499 2500 2501 2502 2503 2504 2505
	case TCP_THIN_LINEAR_TIMEOUTS:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->thin_lto = val;
		break;

A
Andreas Petlund 已提交
2506 2507 2508 2509 2510
	case TCP_THIN_DUPACK:
		if (val < 0 || val > 1)
			err = -EINVAL;
		break;

P
Pavel Emelyanov 已提交
2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546
	case TCP_REPAIR:
		if (!tcp_can_repair_sock(sk))
			err = -EPERM;
		else if (val == 1) {
			tp->repair = 1;
			sk->sk_reuse = SK_FORCE_REUSE;
			tp->repair_queue = TCP_NO_QUEUE;
		} else if (val == 0) {
			tp->repair = 0;
			sk->sk_reuse = SK_NO_REUSE;
			tcp_send_window_probe(sk);
		} else
			err = -EINVAL;

		break;

	case TCP_REPAIR_QUEUE:
		if (!tp->repair)
			err = -EPERM;
		else if (val < TCP_QUEUES_NR)
			tp->repair_queue = val;
		else
			err = -EINVAL;
		break;

	case TCP_QUEUE_SEQ:
		if (sk->sk_state != TCP_CLOSE)
			err = -EPERM;
		else if (tp->repair_queue == TCP_SEND_QUEUE)
			tp->write_seq = val;
		else if (tp->repair_queue == TCP_RECV_QUEUE)
			tp->rcv_nxt = val;
		else
			err = -EINVAL;
		break;

2547 2548 2549 2550
	case TCP_REPAIR_OPTIONS:
		if (!tp->repair)
			err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
2551 2552 2553
			err = tcp_repair_options_est(tp,
					(struct tcp_repair_opt __user *)optval,
					optlen);
2554 2555 2556 2557
		else
			err = -EPERM;
		break;

L
Linus Torvalds 已提交
2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575
	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;
2576
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587
		}
		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))) {
2588
				u32 elapsed = keepalive_time_elapsed(tp);
L
Linus Torvalds 已提交
2589 2590 2591 2592
				if (tp->keepalive_time > elapsed)
					elapsed = tp->keepalive_time - elapsed;
				else
					elapsed = 0;
2593
				inet_csk_reset_keepalive_timer(sk, elapsed);
L
Linus Torvalds 已提交
2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612
			}
		}
		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
2613
			icsk->icsk_syn_retries = val;
L
Linus Torvalds 已提交
2614 2615
		break;

2616 2617 2618 2619 2620 2621 2622
	case TCP_SAVE_SYN:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->save_syn = val;
		break;

L
Linus Torvalds 已提交
2623 2624 2625
	case TCP_LINGER2:
		if (val < 0)
			tp->linger2 = -1;
2626
		else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
L
Linus Torvalds 已提交
2627 2628 2629 2630 2631 2632
			tp->linger2 = 0;
		else
			tp->linger2 = val * HZ;
		break;

	case TCP_DEFER_ACCEPT:
2633 2634 2635 2636
		/* Translate value in seconds to number of retransmits */
		icsk->icsk_accept_queue.rskq_defer_accept =
			secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
					TCP_RTO_MAX / HZ);
L
Linus Torvalds 已提交
2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652
		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) {
2653
			icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2654
		} else {
2655
			icsk->icsk_ack.pingpong = 0;
L
Linus Torvalds 已提交
2656 2657
			if ((1 << sk->sk_state) &
			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2658 2659
			    inet_csk_ack_scheduled(sk)) {
				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2660
				tcp_cleanup_rbuf(sk, 1);
L
Linus Torvalds 已提交
2661
				if (!(val & 1))
2662
					icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2663 2664 2665 2666
			}
		}
		break;

2667 2668 2669 2670 2671 2672
#ifdef CONFIG_TCP_MD5SIG
	case TCP_MD5SIG:
		/* Read the IP->Key mappings from userspace */
		err = tp->af_specific->md5_parse(sk, optval, optlen);
		break;
#endif
2673
	case TCP_USER_TIMEOUT:
2674
		/* Cap the max time in ms TCP will retry or probe the window
2675 2676
		 * before giving up and aborting (ETIMEDOUT) a connection.
		 */
2677 2678 2679 2680
		if (val < 0)
			err = -EINVAL;
		else
			icsk->icsk_user_timeout = msecs_to_jiffies(val);
2681
		break;
2682 2683 2684

	case TCP_FASTOPEN:
		if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2685 2686 2687
		    TCPF_LISTEN))) {
			tcp_fastopen_init_key_once(true);

2688
			fastopen_queue_tune(sk, val);
2689
		} else {
2690
			err = -EINVAL;
2691
		}
2692
		break;
W
Wei Wang 已提交
2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704
	case TCP_FASTOPEN_CONNECT:
		if (val > 1 || val < 0) {
			err = -EINVAL;
		} else if (sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
			if (sk->sk_state == TCP_CLOSE)
				tp->fastopen_connect = val;
			else
				err = -EINVAL;
		} else {
			err = -EOPNOTSUPP;
		}
		break;
2705 2706 2707 2708
	case TCP_TIMESTAMP:
		if (!tp->repair)
			err = -EPERM;
		else
2709
			tp->tsoffset = val - tcp_time_stamp_raw();
2710
		break;
2711 2712 2713
	case TCP_REPAIR_WINDOW:
		err = tcp_repair_set_window(tp, optval, optlen);
		break;
2714 2715 2716 2717
	case TCP_NOTSENT_LOWAT:
		tp->notsent_lowat = val;
		sk->sk_write_space(sk);
		break;
L
Linus Torvalds 已提交
2718 2719 2720
	default:
		err = -ENOPROTOOPT;
		break;
2721 2722
	}

L
Linus Torvalds 已提交
2723 2724 2725 2726
	release_sock(sk);
	return err;
}

2727
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2728
		   unsigned int optlen)
2729
{
2730
	const struct inet_connection_sock *icsk = inet_csk(sk);
2731 2732 2733 2734 2735 2736

	if (level != SOL_TCP)
		return icsk->icsk_af_ops->setsockopt(sk, level, optname,
						     optval, optlen);
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
E
Eric Dumazet 已提交
2737
EXPORT_SYMBOL(tcp_setsockopt);
2738 2739

#ifdef CONFIG_COMPAT
2740
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2741
			  char __user *optval, unsigned int optlen)
2742
{
2743 2744 2745
	if (level != SOL_TCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
2746 2747
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
2748
EXPORT_SYMBOL(compat_tcp_setsockopt);
2749 2750
#endif

2751 2752 2753 2754 2755 2756 2757 2758 2759
static void tcp_get_info_chrono_stats(const struct tcp_sock *tp,
				      struct tcp_info *info)
{
	u64 stats[__TCP_CHRONO_MAX], total = 0;
	enum tcp_chrono i;

	for (i = TCP_CHRONO_BUSY; i < __TCP_CHRONO_MAX; ++i) {
		stats[i] = tp->chrono_stat[i - 1];
		if (i == tp->chrono_type)
2760
			stats[i] += tcp_jiffies32 - tp->chrono_start;
2761 2762 2763 2764 2765 2766 2767 2768 2769
		stats[i] *= USEC_PER_SEC / HZ;
		total += stats[i];
	}

	info->tcpi_busy_time = total;
	info->tcpi_rwnd_limited = stats[TCP_CHRONO_RWND_LIMITED];
	info->tcpi_sndbuf_limited = stats[TCP_CHRONO_SNDBUF_LIMITED];
}

L
Linus Torvalds 已提交
2770
/* Return information about state of tcp endpoint in API format. */
2771
void tcp_get_info(struct sock *sk, struct tcp_info *info)
L
Linus Torvalds 已提交
2772
{
2773
	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
2774
	const struct inet_connection_sock *icsk = inet_csk(sk);
2775
	u32 now, intv;
2776
	u64 rate64;
2777
	bool slow;
2778
	u32 rate;
L
Linus Torvalds 已提交
2779 2780

	memset(info, 0, sizeof(*info));
2781 2782
	if (sk->sk_type != SOCK_STREAM)
		return;
L
Linus Torvalds 已提交
2783

2784 2785
	info->tcpi_state = sk_state_load(sk);

2786 2787 2788
	/* Report meaningful fields for all TCP states, including listeners */
	rate = READ_ONCE(sk->sk_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2789
	info->tcpi_pacing_rate = rate64;
2790 2791 2792

	rate = READ_ONCE(sk->sk_max_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2793
	info->tcpi_max_pacing_rate = rate64;
2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806

	info->tcpi_reordering = tp->reordering;
	info->tcpi_snd_cwnd = tp->snd_cwnd;

	if (info->tcpi_state == TCP_LISTEN) {
		/* listeners aliased fields :
		 * tcpi_unacked -> Number of children ready for accept()
		 * tcpi_sacked  -> max backlog
		 */
		info->tcpi_unacked = sk->sk_ack_backlog;
		info->tcpi_sacked = sk->sk_max_ack_backlog;
		return;
	}
2807 2808 2809

	slow = lock_sock_fast(sk);

2810
	info->tcpi_ca_state = icsk->icsk_ca_state;
2811
	info->tcpi_retransmits = icsk->icsk_retransmits;
2812
	info->tcpi_probes = icsk->icsk_probes_out;
2813
	info->tcpi_backoff = icsk->icsk_backoff;
L
Linus Torvalds 已提交
2814 2815 2816

	if (tp->rx_opt.tstamp_ok)
		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2817
	if (tcp_is_sack(tp))
L
Linus Torvalds 已提交
2818 2819 2820 2821 2822
		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;
2823
	}
L
Linus Torvalds 已提交
2824

E
Eric Dumazet 已提交
2825
	if (tp->ecn_flags & TCP_ECN_OK)
L
Linus Torvalds 已提交
2826
		info->tcpi_options |= TCPI_OPT_ECN;
E
Eric Dumazet 已提交
2827 2828
	if (tp->ecn_flags & TCP_ECN_SEEN)
		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Y
Yuchung Cheng 已提交
2829 2830
	if (tp->syn_data_acked)
		info->tcpi_options |= TCPI_OPT_SYN_DATA;
L
Linus Torvalds 已提交
2831

2832 2833
	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2834
	info->tcpi_snd_mss = tp->mss_cache;
2835
	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
L
Linus Torvalds 已提交
2836

2837 2838 2839
	info->tcpi_unacked = tp->packets_out;
	info->tcpi_sacked = tp->sacked_out;

L
Linus Torvalds 已提交
2840 2841 2842 2843
	info->tcpi_lost = tp->lost_out;
	info->tcpi_retrans = tp->retrans_out;
	info->tcpi_fackets = tp->fackets_out;

2844
	now = tcp_jiffies32;
L
Linus Torvalds 已提交
2845
	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2846
	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
L
Linus Torvalds 已提交
2847 2848
	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);

2849
	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
L
Linus Torvalds 已提交
2850
	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2851 2852
	info->tcpi_rtt = tp->srtt_us >> 3;
	info->tcpi_rttvar = tp->mdev_us >> 2;
L
Linus Torvalds 已提交
2853 2854 2855
	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
	info->tcpi_advmss = tp->advmss;

2856
	info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
L
Linus Torvalds 已提交
2857 2858 2859
	info->tcpi_rcv_space = tp->rcvq_space.space;

	info->tcpi_total_retrans = tp->total_retrans;
2860

2861 2862
	info->tcpi_bytes_acked = tp->bytes_acked;
	info->tcpi_bytes_received = tp->bytes_received;
2863
	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
2864
	tcp_get_info_chrono_stats(tp, info);
2865

2866 2867
	info->tcpi_segs_out = tp->segs_out;
	info->tcpi_segs_in = tp->segs_in;
2868 2869

	info->tcpi_min_rtt = tcp_min_rtt(tp);
2870 2871
	info->tcpi_data_segs_in = tp->data_segs_in;
	info->tcpi_data_segs_out = tp->data_segs_out;
Y
Yuchung Cheng 已提交
2872 2873 2874 2875 2876 2877 2878

	info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
	rate = READ_ONCE(tp->rate_delivered);
	intv = READ_ONCE(tp->rate_interval_us);
	if (rate && intv) {
		rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC;
		do_div(rate64, intv);
2879
		info->tcpi_delivery_rate = rate64;
Y
Yuchung Cheng 已提交
2880
	}
2881
	unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
2882 2883 2884
}
EXPORT_SYMBOL_GPL(tcp_get_info);

2885 2886 2887 2888 2889 2890
struct sk_buff *tcp_get_timestamping_opt_stats(const struct sock *sk)
{
	const struct tcp_sock *tp = tcp_sk(sk);
	struct sk_buff *stats;
	struct tcp_info info;

2891
	stats = alloc_skb(5 * nla_total_size_64bit(sizeof(u64)), GFP_ATOMIC);
2892 2893 2894 2895 2896 2897 2898 2899 2900 2901
	if (!stats)
		return NULL;

	tcp_get_info_chrono_stats(tp, &info);
	nla_put_u64_64bit(stats, TCP_NLA_BUSY,
			  info.tcpi_busy_time, TCP_NLA_PAD);
	nla_put_u64_64bit(stats, TCP_NLA_RWND_LIMITED,
			  info.tcpi_rwnd_limited, TCP_NLA_PAD);
	nla_put_u64_64bit(stats, TCP_NLA_SNDBUF_LIMITED,
			  info.tcpi_sndbuf_limited, TCP_NLA_PAD);
2902 2903 2904 2905
	nla_put_u64_64bit(stats, TCP_NLA_DATA_SEGS_OUT,
			  tp->data_segs_out, TCP_NLA_PAD);
	nla_put_u64_64bit(stats, TCP_NLA_TOTAL_RETRANS,
			  tp->total_retrans, TCP_NLA_PAD);
2906 2907 2908
	return stats;
}

2909 2910
static int do_tcp_getsockopt(struct sock *sk, int level,
		int optname, char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
2911
{
2912
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2913
	struct tcp_sock *tp = tcp_sk(sk);
2914
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926
	int val, len;

	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:
2927
		val = tp->mss_cache;
L
Linus Torvalds 已提交
2928 2929
		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			val = tp->rx_opt.user_mss;
2930 2931
		if (tp->repair)
			val = tp->rx_opt.mss_clamp;
L
Linus Torvalds 已提交
2932 2933 2934 2935 2936 2937 2938 2939
		break;
	case TCP_NODELAY:
		val = !!(tp->nonagle&TCP_NAGLE_OFF);
		break;
	case TCP_CORK:
		val = !!(tp->nonagle&TCP_NAGLE_CORK);
		break;
	case TCP_KEEPIDLE:
E
Eric Dumazet 已提交
2940
		val = keepalive_time_when(tp) / HZ;
L
Linus Torvalds 已提交
2941 2942
		break;
	case TCP_KEEPINTVL:
E
Eric Dumazet 已提交
2943
		val = keepalive_intvl_when(tp) / HZ;
L
Linus Torvalds 已提交
2944 2945
		break;
	case TCP_KEEPCNT:
E
Eric Dumazet 已提交
2946
		val = keepalive_probes(tp);
L
Linus Torvalds 已提交
2947 2948
		break;
	case TCP_SYNCNT:
2949
		val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
L
Linus Torvalds 已提交
2950 2951 2952 2953
		break;
	case TCP_LINGER2:
		val = tp->linger2;
		if (val >= 0)
2954
			val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
L
Linus Torvalds 已提交
2955 2956
		break;
	case TCP_DEFER_ACCEPT:
2957 2958
		val = retrans_to_secs(icsk->icsk_accept_queue.rskq_defer_accept,
				      TCP_TIMEOUT_INIT / HZ, TCP_RTO_MAX / HZ);
L
Linus Torvalds 已提交
2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977
		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;
	}
2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997
	case TCP_CC_INFO: {
		const struct tcp_congestion_ops *ca_ops;
		union tcp_cc_info info;
		size_t sz = 0;
		int attr;

		if (get_user(len, optlen))
			return -EFAULT;

		ca_ops = icsk->icsk_ca_ops;
		if (ca_ops && ca_ops->get_info)
			sz = ca_ops->get_info(sk, ~0U, &attr, &info);

		len = min_t(unsigned int, len, sz);
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, &info, len))
			return -EFAULT;
		return 0;
	}
L
Linus Torvalds 已提交
2998
	case TCP_QUICKACK:
2999
		val = !icsk->icsk_ack.pingpong;
L
Linus Torvalds 已提交
3000
		break;
3001 3002 3003 3004 3005 3006 3007

	case TCP_CONGESTION:
		if (get_user(len, optlen))
			return -EFAULT;
		len = min_t(unsigned int, len, TCP_CA_NAME_MAX);
		if (put_user(len, optlen))
			return -EFAULT;
3008
		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
3009 3010
			return -EFAULT;
		return 0;
3011

3012 3013 3014
	case TCP_THIN_LINEAR_TIMEOUTS:
		val = tp->thin_lto;
		break;
Y
Yuchung Cheng 已提交
3015

3016
	case TCP_THIN_DUPACK:
Y
Yuchung Cheng 已提交
3017
		val = 0;
3018
		break;
3019

P
Pavel Emelyanov 已提交
3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030
	case TCP_REPAIR:
		val = tp->repair;
		break;

	case TCP_REPAIR_QUEUE:
		if (tp->repair)
			val = tp->repair_queue;
		else
			return -EINVAL;
		break;

3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052
	case TCP_REPAIR_WINDOW: {
		struct tcp_repair_window opt;

		if (get_user(len, optlen))
			return -EFAULT;

		if (len != sizeof(opt))
			return -EINVAL;

		if (!tp->repair)
			return -EPERM;

		opt.snd_wl1	= tp->snd_wl1;
		opt.snd_wnd	= tp->snd_wnd;
		opt.max_window	= tp->max_window;
		opt.rcv_wnd	= tp->rcv_wnd;
		opt.rcv_wup	= tp->rcv_wup;

		if (copy_to_user(optval, &opt, len))
			return -EFAULT;
		return 0;
	}
P
Pavel Emelyanov 已提交
3053 3054 3055 3056 3057 3058 3059 3060 3061
	case TCP_QUEUE_SEQ:
		if (tp->repair_queue == TCP_SEND_QUEUE)
			val = tp->write_seq;
		else if (tp->repair_queue == TCP_RECV_QUEUE)
			val = tp->rcv_nxt;
		else
			return -EINVAL;
		break;

3062 3063 3064
	case TCP_USER_TIMEOUT:
		val = jiffies_to_msecs(icsk->icsk_user_timeout);
		break;
3065 3066

	case TCP_FASTOPEN:
3067
		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3068 3069
		break;

W
Wei Wang 已提交
3070 3071 3072 3073
	case TCP_FASTOPEN_CONNECT:
		val = tp->fastopen_connect;
		break;

3074
	case TCP_TIMESTAMP:
3075
		val = tcp_time_stamp_raw() + tp->tsoffset;
3076
		break;
3077 3078 3079
	case TCP_NOTSENT_LOWAT:
		val = tp->notsent_lowat;
		break;
3080 3081 3082 3083 3084 3085 3086 3087 3088
	case TCP_SAVE_SYN:
		val = tp->save_syn;
		break;
	case TCP_SAVED_SYN: {
		if (get_user(len, optlen))
			return -EFAULT;

		lock_sock(sk);
		if (tp->saved_syn) {
3089 3090 3091 3092 3093 3094 3095 3096 3097
			if (len < tp->saved_syn[0]) {
				if (put_user(tp->saved_syn[0], optlen)) {
					release_sock(sk);
					return -EFAULT;
				}
				release_sock(sk);
				return -EINVAL;
			}
			len = tp->saved_syn[0];
3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115
			if (put_user(len, optlen)) {
				release_sock(sk);
				return -EFAULT;
			}
			if (copy_to_user(optval, tp->saved_syn + 1, len)) {
				release_sock(sk);
				return -EFAULT;
			}
			tcp_saved_syn_free(tp);
			release_sock(sk);
		} else {
			release_sock(sk);
			len = 0;
			if (put_user(len, optlen))
				return -EFAULT;
		}
		return 0;
	}
L
Linus Torvalds 已提交
3116 3117
	default:
		return -ENOPROTOOPT;
3118
	}
L
Linus Torvalds 已提交
3119 3120 3121 3122 3123 3124 3125 3126

	if (put_user(len, optlen))
		return -EFAULT;
	if (copy_to_user(optval, &val, len))
		return -EFAULT;
	return 0;
}

3127 3128 3129 3130 3131 3132 3133 3134 3135 3136
int tcp_getsockopt(struct sock *sk, int level, int optname, char __user *optval,
		   int __user *optlen)
{
	struct inet_connection_sock *icsk = inet_csk(sk);

	if (level != SOL_TCP)
		return icsk->icsk_af_ops->getsockopt(sk, level, optname,
						     optval, optlen);
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
E
Eric Dumazet 已提交
3137
EXPORT_SYMBOL(tcp_getsockopt);
3138 3139

#ifdef CONFIG_COMPAT
3140 3141
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
			  char __user *optval, int __user *optlen)
3142
{
3143 3144 3145
	if (level != SOL_TCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
3146 3147
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
3148
EXPORT_SYMBOL(compat_tcp_getsockopt);
3149
#endif
L
Linus Torvalds 已提交
3150

3151
#ifdef CONFIG_TCP_MD5SIG
E
Eric Dumazet 已提交
3152
static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3153
static DEFINE_MUTEX(tcp_md5sig_mutex);
E
Eric Dumazet 已提交
3154
static bool tcp_md5sig_pool_populated = false;
3155

3156
static void __tcp_alloc_md5sig_pool(void)
3157
{
H
Herbert Xu 已提交
3158
	struct crypto_ahash *hash;
3159 3160
	int cpu;

H
Herbert Xu 已提交
3161
	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3162
	if (IS_ERR(hash))
H
Herbert Xu 已提交
3163 3164
		return;

3165
	for_each_possible_cpu(cpu) {
3166
		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
H
Herbert Xu 已提交
3167
		struct ahash_request *req;
3168

3169 3170 3171 3172 3173 3174 3175 3176 3177
		if (!scratch) {
			scratch = kmalloc_node(sizeof(union tcp_md5sum_block) +
					       sizeof(struct tcphdr),
					       GFP_KERNEL,
					       cpu_to_node(cpu));
			if (!scratch)
				return;
			per_cpu(tcp_md5sig_pool, cpu).scratch = scratch;
		}
H
Herbert Xu 已提交
3178 3179 3180 3181 3182 3183 3184 3185 3186 3187
		if (per_cpu(tcp_md5sig_pool, cpu).md5_req)
			continue;

		req = ahash_request_alloc(hash, GFP_KERNEL);
		if (!req)
			return;

		ahash_request_set_callback(req, 0, NULL, NULL);

		per_cpu(tcp_md5sig_pool, cpu).md5_req = req;
3188
	}
E
Eric Dumazet 已提交
3189 3190
	/* before setting tcp_md5sig_pool_populated, we must commit all writes
	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3191 3192
	 */
	smp_wmb();
E
Eric Dumazet 已提交
3193
	tcp_md5sig_pool_populated = true;
3194 3195
}

3196
bool tcp_alloc_md5sig_pool(void)
3197
{
E
Eric Dumazet 已提交
3198
	if (unlikely(!tcp_md5sig_pool_populated)) {
3199 3200
		mutex_lock(&tcp_md5sig_mutex);

E
Eric Dumazet 已提交
3201
		if (!tcp_md5sig_pool_populated)
3202 3203 3204
			__tcp_alloc_md5sig_pool();

		mutex_unlock(&tcp_md5sig_mutex);
3205
	}
E
Eric Dumazet 已提交
3206
	return tcp_md5sig_pool_populated;
3207 3208 3209
}
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);

E
Eric Dumazet 已提交
3210 3211 3212 3213 3214 3215 3216 3217 3218

/**
 *	tcp_get_md5sig_pool - get md5sig_pool for this user
 *
 *	We use percpu structure, so if we succeed, we exit with preemption
 *	and BH disabled, to make sure another thread or softirq handling
 *	wont try to get same context.
 */
struct tcp_md5sig_pool *tcp_get_md5sig_pool(void)
3219
{
E
Eric Dumazet 已提交
3220
	local_bh_disable();
3221

E
Eric Dumazet 已提交
3222 3223 3224 3225 3226
	if (tcp_md5sig_pool_populated) {
		/* coupled with smp_wmb() in __tcp_alloc_md5sig_pool() */
		smp_rmb();
		return this_cpu_ptr(&tcp_md5sig_pool);
	}
E
Eric Dumazet 已提交
3227 3228 3229 3230
	local_bh_enable();
	return NULL;
}
EXPORT_SYMBOL(tcp_get_md5sig_pool);
3231

3232
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3233
			  const struct sk_buff *skb, unsigned int header_len)
3234 3235 3236
{
	struct scatterlist sg;
	const struct tcphdr *tp = tcp_hdr(skb);
H
Herbert Xu 已提交
3237
	struct ahash_request *req = hp->md5_req;
3238 3239 3240
	unsigned int i;
	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
					   skb_headlen(skb) - header_len : 0;
3241
	const struct skb_shared_info *shi = skb_shinfo(skb);
3242
	struct sk_buff *frag_iter;
3243 3244 3245 3246

	sg_init_table(&sg, 1);

	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
H
Herbert Xu 已提交
3247 3248
	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
	if (crypto_ahash_update(req))
3249 3250 3251 3252
		return 1;

	for (i = 0; i < shi->nr_frags; ++i) {
		const struct skb_frag_struct *f = &shi->frags[i];
E
Eric Dumazet 已提交
3253 3254 3255 3256 3257
		unsigned int offset = f->page_offset;
		struct page *page = skb_frag_page(f) + (offset >> PAGE_SHIFT);

		sg_set_page(&sg, page, skb_frag_size(f),
			    offset_in_page(offset));
H
Herbert Xu 已提交
3258 3259
		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
		if (crypto_ahash_update(req))
3260 3261 3262
			return 1;
	}

3263 3264 3265 3266
	skb_walk_frags(skb, frag_iter)
		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
			return 1;

3267 3268 3269 3270
	return 0;
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

3271
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3272 3273 3274 3275
{
	struct scatterlist sg;

	sg_init_one(&sg, key->key, key->keylen);
H
Herbert Xu 已提交
3276 3277
	ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
	return crypto_ahash_update(hp->md5_req);
3278 3279 3280
}
EXPORT_SYMBOL(tcp_md5_hash_key);

3281 3282
#endif

A
Andi Kleen 已提交
3283 3284
void tcp_done(struct sock *sk)
{
3285 3286
	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;

3287
	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3288
		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
A
Andi Kleen 已提交
3289 3290 3291

	tcp_set_state(sk, TCP_CLOSE);
	tcp_clear_xmit_timers(sk);
3292
	if (req)
3293
		reqsk_fastopen_remove(sk, req, false);
A
Andi Kleen 已提交
3294 3295 3296 3297 3298 3299 3300 3301 3302 3303

	sk->sk_shutdown = SHUTDOWN_MASK;

	if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_state_change(sk);
	else
		inet_csk_destroy_sock(sk);
}
EXPORT_SYMBOL_GPL(tcp_done);

3304 3305 3306
int tcp_abort(struct sock *sk, int err)
{
	if (!sk_fullsock(sk)) {
3307 3308 3309 3310 3311 3312 3313 3314 3315
		if (sk->sk_state == TCP_NEW_SYN_RECV) {
			struct request_sock *req = inet_reqsk(sk);

			local_bh_disable();
			inet_csk_reqsk_queue_drop_and_put(req->rsk_listener,
							  req);
			local_bh_enable();
			return 0;
		}
3316 3317 3318 3319 3320 3321
		return -EOPNOTSUPP;
	}

	/* Don't race with userspace socket closes such as tcp_close. */
	lock_sock(sk);

3322 3323 3324 3325 3326
	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);
		inet_csk_listen_stop(sk);
	}

3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347
	/* Don't race with BH socket closes such as inet_csk_listen_stop. */
	local_bh_disable();
	bh_lock_sock(sk);

	if (!sock_flag(sk, SOCK_DEAD)) {
		sk->sk_err = err;
		/* This barrier is coupled with smp_rmb() in tcp_poll() */
		smp_wmb();
		sk->sk_error_report(sk);
		if (tcp_need_reset(sk->sk_state))
			tcp_send_active_reset(sk, GFP_ATOMIC);
		tcp_done(sk);
	}

	bh_unlock_sock(sk);
	local_bh_enable();
	release_sock(sk);
	return 0;
}
EXPORT_SYMBOL_GPL(tcp_abort);

3348
extern struct tcp_congestion_ops tcp_reno;
L
Linus Torvalds 已提交
3349 3350 3351 3352

static __initdata unsigned long thash_entries;
static int __init set_thash_entries(char *str)
{
3353 3354
	ssize_t ret;

L
Linus Torvalds 已提交
3355 3356
	if (!str)
		return 0;
3357 3358 3359 3360 3361

	ret = kstrtoul(str, 0, &thash_entries);
	if (ret)
		return 0;

L
Linus Torvalds 已提交
3362 3363 3364 3365
	return 1;
}
__setup("thash_entries=", set_thash_entries);

F
Fabian Frederick 已提交
3366
static void __init tcp_init_mem(void)
3367
{
E
Eric Dumazet 已提交
3368 3369
	unsigned long limit = nr_free_buffer_pages() / 16;

3370
	limit = max(limit, 128UL);
E
Eric Dumazet 已提交
3371 3372 3373
	sysctl_tcp_mem[0] = limit / 4 * 3;		/* 4.68 % */
	sysctl_tcp_mem[1] = limit;			/* 6.25 % */
	sysctl_tcp_mem[2] = sysctl_tcp_mem[0] * 2;	/* 9.37 % */
3374 3375
}

L
Linus Torvalds 已提交
3376 3377
void __init tcp_init(void)
{
3378
	int max_rshare, max_wshare, cnt;
3379
	unsigned long limit;
3380
	unsigned int i;
L
Linus Torvalds 已提交
3381

3382 3383
	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
L
Linus Torvalds 已提交
3384

3385 3386
	percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
	percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3387
	inet_hashinfo_init(&tcp_hashinfo);
3388 3389 3390
	tcp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("tcp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
3391
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
3392 3393 3394 3395 3396 3397

	/* Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
3398
	tcp_hashinfo.ehash =
L
Linus Torvalds 已提交
3399
		alloc_large_system_hash("TCP established",
3400
					sizeof(struct inet_ehash_bucket),
L
Linus Torvalds 已提交
3401
					thash_entries,
E
Eric Dumazet 已提交
3402
					17, /* one slot per 128 KB of memory */
3403
					0,
L
Linus Torvalds 已提交
3404
					NULL,
3405
					&tcp_hashinfo.ehash_mask,
3406
					0,
3407
					thash_entries ? 0 : 512 * 1024);
E
Eric Dumazet 已提交
3408
	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3409
		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
E
Eric Dumazet 已提交
3410

3411 3412
	if (inet_ehash_locks_alloc(&tcp_hashinfo))
		panic("TCP: failed to alloc ehash_locks");
3413
	tcp_hashinfo.bhash =
L
Linus Torvalds 已提交
3414
		alloc_large_system_hash("TCP bind",
3415
					sizeof(struct inet_bind_hashbucket),
3416
					tcp_hashinfo.ehash_mask + 1,
E
Eric Dumazet 已提交
3417
					17, /* one slot per 128 KB of memory */
3418
					0,
3419
					&tcp_hashinfo.bhash_size,
L
Linus Torvalds 已提交
3420
					NULL,
3421
					0,
L
Linus Torvalds 已提交
3422
					64 * 1024);
3423
	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3424 3425 3426
	for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
		spin_lock_init(&tcp_hashinfo.bhash[i].lock);
		INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
L
Linus Torvalds 已提交
3427 3428
	}

E
Eric Dumazet 已提交
3429 3430 3431

	cnt = tcp_hashinfo.ehash_mask + 1;
	sysctl_tcp_max_orphans = cnt / 2;
L
Linus Torvalds 已提交
3432

3433
	tcp_init_mem();
3434
	/* Set per-socket limits to no more than 1/128 the pressure threshold */
E
Eric Dumazet 已提交
3435
	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3436 3437
	max_wshare = min(4UL*1024*1024, limit);
	max_rshare = min(6UL*1024*1024, limit);
3438

3439
	sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3440
	sysctl_tcp_wmem[1] = 16*1024;
3441
	sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
3442

3443
	sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3444
	sysctl_tcp_rmem[1] = 87380;
3445
	sysctl_tcp_rmem[2] = max(87380, max_rshare);
L
Linus Torvalds 已提交
3446

3447
	pr_info("Hash tables configured (established %u bind %u)\n",
J
Joe Perches 已提交
3448
		tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3449

3450
	tcp_v4_init();
3451
	tcp_metrics_init();
3452
	BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
E
Eric Dumazet 已提交
3453
	tcp_tasklet_init();
L
Linus Torvalds 已提交
3454
}