tcp.c 92.2 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 <linux/errqueue.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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unsigned long tcp_memory_pressure __read_mostly;
EXPORT_SYMBOL_GPL(tcp_memory_pressure);
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void tcp_enter_memory_pressure(struct sock *sk)
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{
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	unsigned long val;

	if (tcp_memory_pressure)
		return;
	val = jiffies;

	if (!val)
		val--;
	if (!cmpxchg(&tcp_memory_pressure, 0, val))
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		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURES);
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}
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EXPORT_SYMBOL_GPL(tcp_enter_memory_pressure);

void tcp_leave_memory_pressure(struct sock *sk)
{
	unsigned long val;

	if (!tcp_memory_pressure)
		return;
	val = xchg(&tcp_memory_pressure, 0);
	if (val)
		NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURESCHRONO,
			      jiffies_to_msecs(jiffies - val));
}
EXPORT_SYMBOL_GPL(tcp_leave_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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static u64 tcp_compute_delivery_rate(const struct tcp_sock *tp)
{
	u32 rate = READ_ONCE(tp->rate_delivered);
	u32 intv = READ_ONCE(tp->rate_interval_us);
	u64 rate64 = 0;

	if (rate && intv) {
		rate64 = (u64)rate * tp->mss_cache * USEC_PER_SEC;
		do_div(rate64, intv);
	}
	return rate64;
}

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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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	sk->tcp_rtx_queue = RB_ROOT;
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	tcp_init_xmit_timers(sk);
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	INIT_LIST_HEAD(&tp->tsq_node);
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	INIT_LIST_HEAD(&tp->tsorted_sent_queue);
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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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void tcp_init_transfer(struct sock *sk, int bpf_op)
{
	struct inet_connection_sock *icsk = inet_csk(sk);

	tcp_mtup_init(sk);
	icsk->icsk_af_ops->rebuild_header(sk);
	tcp_init_metrics(sk);
	tcp_call_bpf(sk, bpf_op);
	tcp_init_congestion_control(sk);
	tcp_init_buffer_space(sk);
}

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static void tcp_tx_timestamp(struct sock *sk, u16 tsflags)
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{
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	struct sk_buff *skb = tcp_write_queue_tail(sk);

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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
	 */
545
	if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
L
Linus Torvalds 已提交
546 547
		mask |= POLLHUP;
	if (sk->sk_shutdown & RCV_SHUTDOWN)
548
		mask |= POLLIN | POLLRDNORM | POLLRDHUP;
L
Linus Torvalds 已提交
549

550
	/* Connected or passive Fast Open socket? */
551 552
	if (state != TCP_SYN_SENT &&
	    (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
553 554 555 556 557
		int target = sock_rcvlowat(sk, 0, INT_MAX);

		if (tp->urg_seq == tp->copied_seq &&
		    !sock_flag(sk, SOCK_URGINLINE) &&
		    tp->urg_data)
558
			target++;
559 560

		if (tp->rcv_nxt - tp->copied_seq >= target)
L
Linus Torvalds 已提交
561 562 563
			mask |= POLLIN | POLLRDNORM;

		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
564
			if (sk_stream_is_writeable(sk)) {
L
Linus Torvalds 已提交
565 566
				mask |= POLLOUT | POLLWRNORM;
			} else {  /* send SIGIO later */
567
				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
568 569 570 571
				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);

				/* Race breaker. If space is freed after
				 * wspace test but before the flags are set,
572 573
				 * IO signal will be lost. Memory barrier
				 * pairs with the input side.
L
Linus Torvalds 已提交
574
				 */
575
				smp_mb__after_atomic();
576
				if (sk_stream_is_writeable(sk))
L
Linus Torvalds 已提交
577 578
					mask |= POLLOUT | POLLWRNORM;
			}
579 580
		} else
			mask |= POLLOUT | POLLWRNORM;
L
Linus Torvalds 已提交
581 582 583

		if (tp->urg_data & TCP_URG_VALID)
			mask |= POLLPRI;
584
	} else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
W
Wei Wang 已提交
585 586 587 588 589
		/* 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
590
	}
T
Tom Marshall 已提交
591 592
	/* This barrier is coupled with smp_wmb() in tcp_reset() */
	smp_rmb();
593
	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
T
Tom Marshall 已提交
594 595
		mask |= POLLERR;

L
Linus Torvalds 已提交
596 597
	return mask;
}
E
Eric Dumazet 已提交
598
EXPORT_SYMBOL(tcp_poll);
L
Linus Torvalds 已提交
599 600 601 602 603

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
604
	bool slow;
L
Linus Torvalds 已提交
605 606 607 608 609 610

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

E
Eric Dumazet 已提交
611
		slow = lock_sock_fast(sk);
612
		answ = tcp_inq(sk);
E
Eric Dumazet 已提交
613
		unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
614 615 616 617 618 619 620 621 622 623 624 625 626
		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;
627 628 629 630 631 632 633 634 635
	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
636 637
	default:
		return -ENOIOCTLCMD;
638
	}
L
Linus Torvalds 已提交
639 640 641

	return put_user(answ, (int __user *)arg);
}
E
Eric Dumazet 已提交
642
EXPORT_SYMBOL(tcp_ioctl);
L
Linus Torvalds 已提交
643 644 645

static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
{
E
Eric Dumazet 已提交
646
	TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
L
Linus Torvalds 已提交
647 648 649
	tp->pushed_seq = tp->write_seq;
}

E
Eric Dumazet 已提交
650
static inline bool forced_push(const struct tcp_sock *tp)
L
Linus Torvalds 已提交
651 652 653 654
{
	return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
}

655
static void skb_entail(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
656
{
657
	struct tcp_sock *tp = tcp_sk(sk);
658 659 660 661
	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
662
	tcb->tcp_flags = TCPHDR_ACK;
663
	tcb->sacked  = 0;
664
	__skb_header_release(skb);
665
	tcp_add_write_queue_tail(sk, skb);
666 667
	sk->sk_wmem_queued += skb->truesize;
	sk_mem_charge(sk, skb->truesize);
668
	if (tp->nonagle & TCP_NAGLE_PUSH)
669
		tp->nonagle &= ~TCP_NAGLE_PUSH;
670 671

	tcp_slow_start_after_idle_check(sk);
L
Linus Torvalds 已提交
672 673
}

674
static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
L
Linus Torvalds 已提交
675
{
I
Ilpo Järvinen 已提交
676
	if (flags & MSG_OOB)
L
Linus Torvalds 已提交
677 678 679
		tp->snd_up = tp->write_seq;
}

E
Eric Dumazet 已提交
680
/* If a not yet filled skb is pushed, do not send it if
681
 * we have data packets in Qdisc or NIC queues :
E
Eric Dumazet 已提交
682 683 684 685
 * 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
686 687 688
 * 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
689 690 691
 */
static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
				int size_goal)
L
Linus Torvalds 已提交
692
{
E
Eric Dumazet 已提交
693 694
	return skb->len < size_goal &&
	       sysctl_tcp_autocorking &&
695
	       skb != tcp_write_queue_head(sk) &&
696
	       refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
E
Eric Dumazet 已提交
697 698 699 700 701 702 703
}

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;
704

E
Eric Dumazet 已提交
705
	skb = tcp_write_queue_tail(sk);
706 707
	if (!skb)
		return;
E
Eric Dumazet 已提交
708 709 710 711 712 713 714 715
	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 */
716
		if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
E
Eric Dumazet 已提交
717
			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
718
			set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
E
Eric Dumazet 已提交
719
		}
720 721 722
		/* It is possible TX completion already happened
		 * before we set TSQ_THROTTLED.
		 */
723
		if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
724
			return;
L
Linus Torvalds 已提交
725
	}
E
Eric Dumazet 已提交
726 727 728 729 730

	if (flags & MSG_MORE)
		nonagle = TCP_NAGLE_CORK;

	__tcp_push_pending_frames(sk, mss_now, nonagle);
L
Linus Torvalds 已提交
731 732
}

733 734
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
735 736
{
	struct tcp_splice_state *tss = rd_desc->arg.data;
737
	int ret;
J
Jens Axboe 已提交
738

739
	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
A
Al Viro 已提交
740
			      min(rd_desc->count, len), tss->flags);
741 742 743
	if (ret > 0)
		rd_desc->count -= ret;
	return ret;
J
Jens Axboe 已提交
744 745 746 747 748 749 750
}

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,
751
		.count	  = tss->len,
J
Jens Axboe 已提交
752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782
	};

	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;

783
	sock_rps_record_flow(sk);
J
Jens Axboe 已提交
784 785 786 787 788 789 790 791 792 793
	/*
	 * We can't seek on a socket input
	 */
	if (unlikely(*ppos))
		return -ESPIPE;

	ret = spliced = 0;

	lock_sock(sk);

794
	timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
J
Jens Axboe 已提交
795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822
	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;
			}
823 824 825 826 827 828
			/* 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;
829
			sk_wait_data(sk, &timeo, NULL);
J
Jens Axboe 已提交
830 831 832 833 834 835 836 837 838
			if (signal_pending(current)) {
				ret = sock_intr_errno(timeo);
				break;
			}
			continue;
		}
		tss.len -= ret;
		spliced += ret;

839 840
		if (!timeo)
			break;
J
Jens Axboe 已提交
841 842 843 844
		release_sock(sk);
		lock_sock(sk);

		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
845
		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
J
Jens Axboe 已提交
846 847 848 849 850 851 852 853 854 855 856
		    signal_pending(current))
			break;
	}

	release_sock(sk);

	if (spliced)
		return spliced;

	return ret;
}
E
Eric Dumazet 已提交
857
EXPORT_SYMBOL(tcp_splice_read);
J
Jens Axboe 已提交
858

859 860
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
				    bool force_schedule)
861 862 863 864 865 866
{
	struct sk_buff *skb;

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

867 868 869
	if (unlikely(tcp_under_memory_pressure(sk)))
		sk_mem_reclaim_partial(sk);

870
	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
871
	if (likely(skb)) {
872
		bool mem_scheduled;
873

874 875
		if (force_schedule) {
			mem_scheduled = true;
876 877
			sk_forced_mem_schedule(sk, skb->truesize);
		} else {
878
			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
879
		}
880
		if (likely(mem_scheduled)) {
881
			skb_reserve(skb, sk->sk_prot->max_header);
882 883 884 885
			/*
			 * Make sure that we have exactly size bytes
			 * available to the caller, no more, no less.
			 */
E
Eric Dumazet 已提交
886
			skb->reserved_tailroom = skb->end - skb->tail - size;
887
			INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
888 889 890 891
			return skb;
		}
		__kfree_skb(skb);
	} else {
892
		sk->sk_prot->enter_memory_pressure(sk);
893 894 895 896 897
		sk_stream_moderate_sndbuf(sk);
	}
	return NULL;
}

I
Ilpo Järvinen 已提交
898 899 900 901
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
				       int large_allowed)
{
	struct tcp_sock *tp = tcp_sk(sk);
902
	u32 new_size_goal, size_goal;
E
Eric Dumazet 已提交
903 904 905 906

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

907 908
	/* 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
909 910 911 912 913 914 915 916 917
	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
918 919
	}

E
Eric Dumazet 已提交
920
	return max(size_goal, mss_now);
I
Ilpo Järvinen 已提交
921 922 923 924 925 926 927 928 929 930 931 932
}

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;
}

933 934
ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
			 size_t size, int flags)
L
Linus Torvalds 已提交
935 936
{
	struct tcp_sock *tp = tcp_sk(sk);
937
	int mss_now, size_goal;
L
Linus Torvalds 已提交
938 939 940 941
	int err;
	ssize_t copied;
	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

942 943 944 945 946 947
	/* 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)) {
948 949
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
950
			goto out_err;
951
	}
L
Linus Torvalds 已提交
952

953
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
954

I
Ilpo Järvinen 已提交
955
	mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
956 957 958 959
	copied = 0;

	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
960
		goto out_err;
L
Linus Torvalds 已提交
961

962
	while (size > 0) {
963
		struct sk_buff *skb = tcp_write_queue_tail(sk);
964 965
		int copy, i;
		bool can_coalesce;
L
Linus Torvalds 已提交
966

967
		if (!skb || (copy = size_goal - skb->len) <= 0 ||
968
		    !tcp_skb_can_collapse_to(skb)) {
L
Linus Torvalds 已提交
969 970 971 972
new_segment:
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;

973
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
974
					tcp_rtx_and_write_queues_empty(sk));
L
Linus Torvalds 已提交
975 976 977
			if (!skb)
				goto wait_for_memory;

978
			skb_entail(sk, skb);
979
			copy = size_goal;
L
Linus Torvalds 已提交
980 981 982 983 984 985 986
		}

		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
987
		if (!can_coalesce && i >= sysctl_max_skb_frags) {
L
Linus Torvalds 已提交
988 989 990
			tcp_mark_push(tp, skb);
			goto new_segment;
		}
991
		if (!sk_wmem_schedule(sk, copy))
L
Linus Torvalds 已提交
992
			goto wait_for_memory;
993

L
Linus Torvalds 已提交
994
		if (can_coalesce) {
E
Eric Dumazet 已提交
995
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
L
Linus Torvalds 已提交
996 997 998 999
		} else {
			get_page(page);
			skb_fill_page_desc(skb, i, page, offset, copy);
		}
1000
		skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1001

L
Linus Torvalds 已提交
1002 1003 1004 1005
		skb->len += copy;
		skb->data_len += copy;
		skb->truesize += copy;
		sk->sk_wmem_queued += copy;
1006
		sk_mem_charge(sk, copy);
1007
		skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1008 1009
		tp->write_seq += copy;
		TCP_SKB_CB(skb)->end_seq += copy;
1010
		tcp_skb_pcount_set(skb, 0);
L
Linus Torvalds 已提交
1011 1012

		if (!copied)
E
Eric Dumazet 已提交
1013
			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
L
Linus Torvalds 已提交
1014 1015

		copied += copy;
1016
		offset += copy;
1017
		size -= copy;
1018
		if (!size)
L
Linus Torvalds 已提交
1019 1020
			goto out;

1021
		if (skb->len < size_goal || (flags & MSG_OOB))
L
Linus Torvalds 已提交
1022 1023 1024 1025
			continue;

		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
1026
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1027
		} else if (skb == tcp_send_head(sk))
L
Linus Torvalds 已提交
1028 1029 1030 1031 1032 1033
			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
1034 1035
		tcp_push(sk, flags & ~MSG_MORE, mss_now,
			 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1036

1037 1038
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
1039 1040
			goto do_error;

I
Ilpo Järvinen 已提交
1041
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1042 1043 1044
	}

out:
1045
	if (copied) {
E
Eric Dumazet 已提交
1046
		tcp_tx_timestamp(sk, sk->sk_tsflags);
1047 1048 1049
		if (!(flags & MSG_SENDPAGE_NOTLAST))
			tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
	}
L
Linus Torvalds 已提交
1050 1051 1052 1053 1054 1055
	return copied;

do_error:
	if (copied)
		goto out;
out_err:
1056
	/* make sure we wake any epoll edge trigger waiter */
1057 1058
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1059
		sk->sk_write_space(sk);
1060 1061
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1062 1063
	return sk_stream_error(sk, flags, err);
}
1064
EXPORT_SYMBOL_GPL(do_tcp_sendpages);
L
Linus Torvalds 已提交
1065

1066 1067
int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset,
			size_t size, int flags)
L
Linus Torvalds 已提交
1068 1069
{
	if (!(sk->sk_route_caps & NETIF_F_SG) ||
1070
	    !sk_check_csum_caps(sk))
1071
		return sock_no_sendpage_locked(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1072

1073 1074
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1075 1076
	return do_tcp_sendpages(sk, page, offset, size, flags);
}
1077
EXPORT_SYMBOL_GPL(tcp_sendpage_locked);
1078 1079 1080 1081 1082 1083 1084 1085

int tcp_sendpage(struct sock *sk, struct page *page, int offset,
		 size_t size, int flags)
{
	int ret;

	lock_sock(sk);
	ret = tcp_sendpage_locked(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1086
	release_sock(sk);
1087 1088

	return ret;
L
Linus Torvalds 已提交
1089
}
E
Eric Dumazet 已提交
1090
EXPORT_SYMBOL(tcp_sendpage);
L
Linus Torvalds 已提交
1091

1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109
/* 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
1110
{
1111
	const struct tcp_sock *tp = tcp_sk(sk);
1112
	int tmp = tp->mss_cache;
L
Linus Torvalds 已提交
1113

K
Krishna Kumar 已提交
1114
	if (sg) {
1115
		if (sk_can_gso(sk)) {
1116
			tmp = linear_payload_sz(first_skb);
1117
		} else {
1118 1119 1120 1121 1122 1123 1124
			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
1125 1126 1127 1128

	return tmp;
}

1129 1130
void tcp_free_fastopen_req(struct tcp_sock *tp)
{
1131
	if (tp->fastopen_req) {
1132 1133 1134 1135 1136
		kfree(tp->fastopen_req);
		tp->fastopen_req = NULL;
	}
}

1137 1138
static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
				int *copied, size_t size)
1139 1140
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Wei Wang 已提交
1141
	struct inet_sock *inet = inet_sk(sk);
1142
	struct sockaddr *uaddr = msg->msg_name;
1143 1144
	int err, flags;

1145
	if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
1146 1147
	    (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
	     uaddr->sa_family == AF_UNSPEC))
1148
		return -EOPNOTSUPP;
1149
	if (tp->fastopen_req)
1150 1151 1152 1153
		return -EALREADY; /* Another Fast Open is in progress */

	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
				   sk->sk_allocation);
1154
	if (unlikely(!tp->fastopen_req))
1155 1156
		return -ENOBUFS;
	tp->fastopen_req->data = msg;
1157
	tp->fastopen_req->size = size;
1158

W
Wei Wang 已提交
1159 1160 1161 1162 1163 1164 1165 1166 1167
	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;
		}
	}
1168
	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1169
	err = __inet_stream_connect(sk->sk_socket, uaddr,
1170
				    msg->msg_namelen, flags, 1);
1171 1172 1173 1174 1175 1176 1177 1178
	/* 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;
	}
1179 1180 1181
	return err;
}

1182
int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
L
Linus Torvalds 已提交
1183 1184
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Willem de Bruijn 已提交
1185
	struct ubuf_info *uarg = NULL;
L
Linus Torvalds 已提交
1186
	struct sk_buff *skb;
1187
	struct sockcm_cookie sockc;
1188 1189
	int flags, err, copied = 0;
	int mss_now = 0, size_goal, copied_syn = 0;
1190
	bool process_backlog = false;
1191
	bool sg;
L
Linus Torvalds 已提交
1192 1193 1194
	long timeo;

	flags = msg->msg_flags;
W
Willem de Bruijn 已提交
1195 1196 1197 1198 1199 1200 1201

	if (flags & MSG_ZEROCOPY && size) {
		if (sk->sk_state != TCP_ESTABLISHED) {
			err = -EINVAL;
			goto out_err;
		}

1202
		skb = tcp_write_queue_tail(sk);
W
Willem de Bruijn 已提交
1203 1204 1205 1206 1207 1208 1209 1210 1211 1212
		uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb));
		if (!uarg) {
			err = -ENOBUFS;
			goto out_err;
		}

		if (!(sk_check_csum_caps(sk) && sk->sk_route_caps & NETIF_F_SG))
			uarg->zerocopy = 0;
	}

W
Wei Wang 已提交
1213
	if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect)) {
1214
		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1215 1216 1217 1218 1219 1220
		if (err == -EINPROGRESS && copied_syn > 0)
			goto out;
		else if (err)
			goto out_err;
	}

L
Linus Torvalds 已提交
1221 1222
	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

1223 1224
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1225 1226 1227 1228 1229 1230
	/* 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)) {
1231 1232
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
1233
			goto do_error;
1234
	}
L
Linus Torvalds 已提交
1235

P
Pavel Emelyanov 已提交
1236 1237 1238
	if (unlikely(tp->repair)) {
		if (tp->repair_queue == TCP_RECV_QUEUE) {
			copied = tcp_send_rcvq(sk, msg, size);
1239
			goto out_nopush;
P
Pavel Emelyanov 已提交
1240 1241 1242 1243 1244 1245 1246 1247 1248
		}

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

		/* 'common' sending to sendq */
	}

1249 1250 1251 1252 1253 1254 1255 1256 1257
	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
1258
	/* This should be in poll */
1259
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
1260 1261 1262 1263

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

1264 1265 1266
restart:
	mss_now = tcp_send_mss(sk, &size_goal, flags);

L
Linus Torvalds 已提交
1267 1268
	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1269
		goto do_error;
L
Linus Torvalds 已提交
1270

1271
	sg = !!(sk->sk_route_caps & NETIF_F_SG);
K
Krishna Kumar 已提交
1272

A
Al Viro 已提交
1273
	while (msg_data_left(msg)) {
1274 1275
		int copy = 0;
		int max = size_goal;
L
Linus Torvalds 已提交
1276

1277
		skb = tcp_write_queue_tail(sk);
1278
		if (skb) {
1279 1280 1281
			if (skb->ip_summed == CHECKSUM_NONE)
				max = mss_now;
			copy = max - skb->len;
1282
		}
L
Linus Torvalds 已提交
1283

1284
		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1285 1286
			bool first_skb;

L
Linus Torvalds 已提交
1287
new_segment:
1288 1289 1290 1291 1292
			/* 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
1293

1294 1295
			if (process_backlog && sk_flush_backlog(sk)) {
				process_backlog = false;
1296
				goto restart;
1297
			}
1298
			first_skb = tcp_rtx_and_write_queues_empty(sk);
1299
			skb = sk_stream_alloc_skb(sk,
1300
						  select_size(sk, sg, first_skb),
1301
						  sk->sk_allocation,
1302
						  first_skb);
1303 1304
			if (!skb)
				goto wait_for_memory;
L
Linus Torvalds 已提交
1305

1306
			process_backlog = true;
1307 1308 1309
			/*
			 * Check whether we can use HW checksum.
			 */
1310
			if (sk_check_csum_caps(sk))
1311
				skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1312

1313 1314 1315
			skb_entail(sk, skb);
			copy = size_goal;
			max = size_goal;
1316

1317 1318 1319 1320 1321 1322 1323
			/* 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
1324

1325
		/* Try to append data to the end of skb. */
A
Al Viro 已提交
1326 1327
		if (copy > msg_data_left(msg))
			copy = msg_data_left(msg);
1328 1329 1330 1331 1332 1333 1334 1335

		/* 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;
W
Willem de Bruijn 已提交
1336
		} else if (!uarg || !uarg->zerocopy) {
1337 1338 1339 1340 1341 1342
			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;
1343

1344 1345
			if (!skb_can_coalesce(skb, i, pfrag->page,
					      pfrag->offset)) {
1346
				if (i >= sysctl_max_skb_frags || !sg) {
1347 1348
					tcp_mark_push(tp, skb);
					goto new_segment;
L
Linus Torvalds 已提交
1349
				}
1350
				merge = false;
L
Linus Torvalds 已提交
1351 1352
			}

1353 1354 1355 1356
			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
1357

1358 1359 1360 1361 1362 1363
			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
1364

1365 1366 1367 1368 1369 1370
			/* 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);
1371
				page_ref_inc(pfrag->page);
1372
			}
1373
			pfrag->offset += copy;
W
Willem de Bruijn 已提交
1374 1375 1376 1377 1378 1379 1380
		} else {
			err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
			if (err == -EMSGSIZE || err == -EEXIST)
				goto new_segment;
			if (err < 0)
				goto do_error;
			copy = err;
1381 1382 1383 1384 1385 1386 1387 1388
		}

		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
1389

1390
		copied += copy;
A
Al Viro 已提交
1391
		if (!msg_data_left(msg)) {
1392 1393
			if (unlikely(flags & MSG_EOR))
				TCP_SKB_CB(skb)->eor = 1;
1394 1395
			goto out;
		}
L
Linus Torvalds 已提交
1396

1397
		if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
L
Linus Torvalds 已提交
1398 1399
			continue;

1400 1401 1402 1403 1404 1405 1406
		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
1407
wait_for_sndbuf:
1408
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
L
Linus Torvalds 已提交
1409
wait_for_memory:
1410 1411 1412
		if (copied)
			tcp_push(sk, flags & ~MSG_MORE, mss_now,
				 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1413

1414 1415
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
1416
			goto do_error;
L
Linus Torvalds 已提交
1417

1418
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1419 1420 1421
	}

out:
1422
	if (copied) {
E
Eric Dumazet 已提交
1423
		tcp_tx_timestamp(sk, sockc.tsflags);
E
Eric Dumazet 已提交
1424
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1425
	}
1426
out_nopush:
W
Willem de Bruijn 已提交
1427
	sock_zerocopy_put(uarg);
1428
	return copied + copied_syn;
L
Linus Torvalds 已提交
1429 1430 1431

do_fault:
	if (!skb->len) {
1432 1433 1434 1435 1436
		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);
1437
		sk_wmem_free_skb(sk, skb);
L
Linus Torvalds 已提交
1438 1439 1440
	}

do_error:
1441
	if (copied + copied_syn)
L
Linus Torvalds 已提交
1442 1443
		goto out;
out_err:
W
Willem de Bruijn 已提交
1444
	sock_zerocopy_put_abort(uarg);
L
Linus Torvalds 已提交
1445
	err = sk_stream_error(sk, flags, err);
1446
	/* make sure we wake any epoll edge trigger waiter */
1447 1448
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1449
		sk->sk_write_space(sk);
1450 1451
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1452 1453
	return err;
}
1454
EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465

int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
{
	int ret;

	lock_sock(sk);
	ret = tcp_sendmsg_locked(sk, msg, size);
	release_sock(sk);

	return ret;
}
E
Eric Dumazet 已提交
1466
EXPORT_SYMBOL(tcp_sendmsg);
L
Linus Torvalds 已提交
1467 1468 1469 1470 1471 1472

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

1473
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
L
Linus Torvalds 已提交
1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496
{
	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
1497
				err = memcpy_to_msg(msg, &c, 1);
L
Linus Torvalds 已提交
1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516
			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
1517 1518 1519 1520 1521 1522 1523
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 */

1524 1525 1526 1527 1528 1529 1530
	skb_rbtree_walk(skb, &sk->tcp_rtx_queue) {
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
		if (err)
			return err;
		copied += skb->len;
	}

P
Pavel Emelyanov 已提交
1531
	skb_queue_walk(&sk->sk_write_queue, skb) {
1532
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
P
Pavel Emelyanov 已提交
1533 1534 1535 1536 1537 1538 1539 1540 1541
		if (err)
			break;

		copied += skb->len;
	}

	return err ?: copied;
}

L
Linus Torvalds 已提交
1542 1543 1544 1545 1546 1547
/* 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.
 */
1548
static void tcp_cleanup_rbuf(struct sock *sk, int copied)
L
Linus Torvalds 已提交
1549 1550
{
	struct tcp_sock *tp = tcp_sk(sk);
E
Eric Dumazet 已提交
1551
	bool time_to_ack = false;
L
Linus Torvalds 已提交
1552 1553 1554

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

1555
	WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
J
Joe Perches 已提交
1556
	     "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1557
	     tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
L
Linus Torvalds 已提交
1558

1559 1560
	if (inet_csk_ack_scheduled(sk)) {
		const struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1561 1562
		   /* Delayed ACKs frequently hit locked sockets during bulk
		    * receive. */
1563
		if (icsk->icsk_ack.blocked ||
L
Linus Torvalds 已提交
1564
		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
1565
		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
L
Linus Torvalds 已提交
1566 1567 1568 1569 1570 1571
		    /*
		     * 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.
		     */
1572 1573 1574 1575 1576
		    (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
1577
			time_to_ack = true;
L
Linus Torvalds 已提交
1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598
	}

	/* 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
1599
				time_to_ack = true;
L
Linus Torvalds 已提交
1600 1601 1602 1603 1604 1605
		}
	}
	if (time_to_ack)
		tcp_send_ack(sk);
}

1606
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
L
Linus Torvalds 已提交
1607 1608 1609 1610
{
	struct sk_buff *skb;
	u32 offset;

1611
	while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
L
Linus Torvalds 已提交
1612
		offset = seq - TCP_SKB_CB(skb)->seq;
1613 1614
		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
1615
			offset--;
1616
		}
1617
		if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
L
Linus Torvalds 已提交
1618 1619 1620
			*off = offset;
			return skb;
		}
1621 1622 1623 1624
		/* 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
1625
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653
	}
	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) {
1654 1655
			int used;
			size_t len;
L
Linus Torvalds 已提交
1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666

			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);
1667
			if (used <= 0) {
1668 1669 1670 1671
				if (!copied)
					copied = used;
				break;
			} else if (used <= len) {
L
Linus Torvalds 已提交
1672 1673 1674 1675
				seq += used;
				copied += used;
				offset += used;
			}
1676
			/* If recv_actor drops the lock (e.g. TCP splice
1677 1678 1679 1680
			 * receive) the skb pointer might be invalid when
			 * getting here: tcp_collapse might have deleted it
			 * while aggregating skbs from the socket queue.
			 */
1681 1682
			skb = tcp_recv_skb(sk, seq - 1, &offset);
			if (!skb)
L
Linus Torvalds 已提交
1683
				break;
1684 1685 1686 1687 1688
			/* 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
1689
		}
1690
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
D
Dan Williams 已提交
1691
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1692 1693 1694
			++seq;
			break;
		}
D
Dan Williams 已提交
1695
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1696 1697
		if (!desc->count)
			break;
1698
		tp->copied_seq = seq;
L
Linus Torvalds 已提交
1699 1700 1701 1702 1703 1704
	}
	tp->copied_seq = seq;

	tcp_rcv_space_adjust(sk);

	/* Clean up data we have read: This will do ACK frames. */
1705 1706
	if (copied > 0) {
		tcp_recv_skb(sk, seq, &offset);
1707
		tcp_cleanup_rbuf(sk, copied);
1708
	}
L
Linus Torvalds 已提交
1709 1710
	return copied;
}
E
Eric Dumazet 已提交
1711
EXPORT_SYMBOL(tcp_read_sock);
L
Linus Torvalds 已提交
1712

1713 1714 1715 1716 1717 1718
int tcp_peek_len(struct socket *sock)
{
	return tcp_inq(sock->sk);
}
EXPORT_SYMBOL(tcp_peek_len);

1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 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
static void tcp_update_recv_tstamps(struct sk_buff *skb,
				    struct scm_timestamping *tss)
{
	if (skb->tstamp)
		tss->ts[0] = ktime_to_timespec(skb->tstamp);
	else
		tss->ts[0] = (struct timespec) {0};

	if (skb_hwtstamps(skb)->hwtstamp)
		tss->ts[2] = ktime_to_timespec(skb_hwtstamps(skb)->hwtstamp);
	else
		tss->ts[2] = (struct timespec) {0};
}

/* Similar to __sock_recv_timestamp, but does not require an skb */
void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
			struct scm_timestamping *tss)
{
	struct timeval tv;
	bool has_timestamping = false;

	if (tss->ts[0].tv_sec || tss->ts[0].tv_nsec) {
		if (sock_flag(sk, SOCK_RCVTSTAMP)) {
			if (sock_flag(sk, SOCK_RCVTSTAMPNS)) {
				put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPNS,
					 sizeof(tss->ts[0]), &tss->ts[0]);
			} else {
				tv.tv_sec = tss->ts[0].tv_sec;
				tv.tv_usec = tss->ts[0].tv_nsec / 1000;

				put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMP,
					 sizeof(tv), &tv);
			}
		}

		if (sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE)
			has_timestamping = true;
		else
			tss->ts[0] = (struct timespec) {0};
	}

	if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) {
		if (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)
			has_timestamping = true;
		else
			tss->ts[2] = (struct timespec) {0};
	}

	if (has_timestamping) {
		tss->ts[1] = (struct timespec) {0};
		put_cmsg(msg, SOL_SOCKET, SCM_TIMESTAMPING,
			 sizeof(*tss), tss);
	}
}

L
Linus Torvalds 已提交
1774 1775 1776 1777 1778 1779 1780 1781
/*
 *	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.
 */

1782 1783
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
1784 1785 1786 1787 1788 1789 1790 1791 1792
{
	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;
1793
	struct sk_buff *skb, *last;
I
Ilpo Järvinen 已提交
1794
	u32 urg_hole = 0;
1795 1796
	struct scm_timestamping tss;
	bool has_tss = false;
L
Linus Torvalds 已提交
1797

1798
	if (unlikely(flags & MSG_ERRQUEUE))
1799
		return inet_recv_error(sk, msg, len, addr_len);
1800

1801 1802 1803
	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
	    (sk->sk_state == TCP_ESTABLISHED))
		sk_busy_loop(sk, nonblock);
1804

L
Linus Torvalds 已提交
1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816
	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
1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831
	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
1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854
	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. */

1855
		last = skb_peek_tail(&sk->sk_receive_queue);
1856
		skb_queue_walk(&sk->sk_receive_queue, skb) {
1857
			last = skb;
L
Linus Torvalds 已提交
1858 1859 1860
			/* Now that we have two receive queues this
			 * shouldn't happen.
			 */
1861
			if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
J
Joe Perches 已提交
1862 1863 1864
				 "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
1865
				break;
1866

L
Linus Torvalds 已提交
1867
			offset = *seq - TCP_SKB_CB(skb)->seq;
1868 1869
			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
1870
				offset--;
1871
			}
L
Linus Torvalds 已提交
1872 1873
			if (offset < skb->len)
				goto found_ok_skb;
1874
			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1875
				goto found_fin_ok;
J
Joe Perches 已提交
1876 1877 1878
			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);
1879
		}
L
Linus Torvalds 已提交
1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890

		/* 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 ||
1891
			    signal_pending(current))
L
Linus Torvalds 已提交
1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926
				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;
			}
		}

1927
		tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1928 1929 1930 1931 1932

		if (copied >= target) {
			/* Do not sleep, just process backlog. */
			release_sock(sk);
			lock_sock(sk);
1933 1934 1935
		} else {
			sk_wait_data(sk, &timeo, last);
		}
L
Linus Torvalds 已提交
1936

I
Ilpo Järvinen 已提交
1937 1938
		if ((flags & MSG_PEEK) &&
		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
1939 1940 1941
			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
1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958
			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
1959
						urg_hole++;
L
Linus Torvalds 已提交
1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970
						offset++;
						used--;
						if (!used)
							goto skip_copy;
					}
				} else
					used = urg_offset;
			}
		}

		if (!(flags & MSG_TRUNC)) {
1971
			err = skb_copy_datagram_msg(skb, offset, msg, used);
D
Dan Williams 已提交
1972 1973 1974 1975 1976
			if (err) {
				/* Exception. Bailout! */
				if (!copied)
					copied = -EFAULT;
				break;
L
Linus Torvalds 已提交
1977 1978 1979 1980 1981 1982 1983 1984 1985 1986
			}
		}

		*seq += used;
		copied += used;
		len -= used;

		tcp_rcv_space_adjust(sk);

skip_copy:
1987
		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
L
Linus Torvalds 已提交
1988
			tp->urg_data = 0;
1989 1990
			tcp_fast_path_check(sk);
		}
L
Linus Torvalds 已提交
1991 1992 1993
		if (used + offset < skb->len)
			continue;

1994 1995 1996 1997
		if (TCP_SKB_CB(skb)->has_rxtstamp) {
			tcp_update_recv_tstamps(skb, &tss);
			has_tss = true;
		}
1998
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1999
			goto found_fin_ok;
D
Dan Williams 已提交
2000 2001
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
2002 2003 2004 2005 2006
		continue;

	found_fin_ok:
		/* Process the FIN. */
		++*seq;
D
Dan Williams 已提交
2007 2008
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
2009 2010 2011 2012 2013 2014 2015
		break;
	} while (len > 0);

	/* According to UNIX98, msg_name/msg_namelen are ignored
	 * on connected socket. I was just happy when found this 8) --ANK
	 */

2016 2017 2018
	if (has_tss)
		tcp_recv_timestamp(msg, sk, &tss);

L
Linus Torvalds 已提交
2019
	/* Clean up data we have read: This will do ACK frames. */
2020
	tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
2021 2022 2023 2024 2025 2026 2027 2028 2029

	release_sock(sk);
	return copied;

out:
	release_sock(sk);
	return err;

recv_urg:
2030
	err = tcp_recv_urg(sk, msg, len, flags);
L
Linus Torvalds 已提交
2031
	goto out;
P
Pavel Emelyanov 已提交
2032 2033 2034 2035

recv_sndq:
	err = tcp_peek_sndq(sk, msg, len);
	goto out;
L
Linus Torvalds 已提交
2036
}
E
Eric Dumazet 已提交
2037
EXPORT_SYMBOL(tcp_recvmsg);
L
Linus Torvalds 已提交
2038

I
Ilpo Järvinen 已提交
2039 2040 2041 2042 2043 2044 2045
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
2046
			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2047 2048 2049 2050
		break;

	case TCP_CLOSE:
		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2051
			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
I
Ilpo Järvinen 已提交
2052 2053 2054 2055

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2056
			inet_put_port(sk);
I
Ilpo Järvinen 已提交
2057 2058
		/* fall through */
	default:
2059
		if (oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2060
			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2061 2062 2063 2064 2065
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
2066
	sk_state_store(sk, state);
I
Ilpo Järvinen 已提交
2067 2068

#ifdef STATE_TRACE
2069
	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
I
Ilpo Järvinen 已提交
2070 2071 2072 2073
#endif
}
EXPORT_SYMBOL_GPL(tcp_set_state);

L
Linus Torvalds 已提交
2074 2075 2076 2077 2078 2079 2080
/*
 *	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.
 */

2081
static const unsigned char new_state[16] = {
L
Linus Torvalds 已提交
2082
  /* current state:        new state:      action:	*/
2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095
  [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
2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109
};

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
2110
 *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
L
Linus Torvalds 已提交
2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130
 */

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
2131
EXPORT_SYMBOL(tcp_shutdown);
L
Linus Torvalds 已提交
2132

A
Arun Sharma 已提交
2133 2134 2135 2136 2137 2138 2139
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);

2140 2141 2142 2143
	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
2144 2145 2146
	return too_many_orphans || out_of_socket_memory;
}

L
Linus Torvalds 已提交
2147 2148 2149 2150
void tcp_close(struct sock *sk, long timeout)
{
	struct sk_buff *skb;
	int data_was_unread = 0;
H
Herbert Xu 已提交
2151
	int state;
L
Linus Torvalds 已提交
2152 2153 2154 2155 2156 2157 2158 2159

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

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

		/* Special case. */
2160
		inet_csk_listen_stop(sk);
L
Linus Torvalds 已提交
2161 2162 2163 2164 2165 2166 2167 2168 2169

		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) {
2170 2171 2172 2173
		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
2174 2175 2176 2177
		data_was_unread += len;
		__kfree_skb(skb);
	}

2178
	sk_mem_reclaim(sk);
L
Linus Torvalds 已提交
2179

2180 2181 2182 2183
	/* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
	if (sk->sk_state == TCP_CLOSE)
		goto adjudge_to_death;

2184 2185 2186 2187 2188 2189
	/* 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
2190
	 */
P
Pavel Emelyanov 已提交
2191 2192 2193
	if (unlikely(tcp_sk(sk)->repair)) {
		sk->sk_prot->disconnect(sk, 0);
	} else if (data_was_unread) {
L
Linus Torvalds 已提交
2194
		/* Unread data was tossed, zap the connection. */
2195
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
L
Linus Torvalds 已提交
2196
		tcp_set_state(sk, TCP_CLOSE);
2197
		tcp_send_active_reset(sk, sk->sk_allocation);
L
Linus Torvalds 已提交
2198 2199 2200
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
2201
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
L
Linus Torvalds 已提交
2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226
	} 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
2227 2228 2229 2230
		 * 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
2231 2232 2233 2234 2235 2236 2237
		 */
		tcp_send_fin(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
H
Herbert Xu 已提交
2238 2239 2240 2241
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

L
Linus Torvalds 已提交
2242 2243 2244 2245 2246
	/* 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
2247
	 *  to finish close. No need to check for user refs.
L
Linus Torvalds 已提交
2248 2249 2250
	 */
	local_bh_disable();
	bh_lock_sock(sk);
2251
	WARN_ON(sock_owned_by_user(sk));
L
Linus Torvalds 已提交
2252

H
Herbert Xu 已提交
2253 2254
	percpu_counter_inc(sk->sk_prot->orphan_count);

H
Herbert Xu 已提交
2255 2256 2257
	/* 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
2258 2259 2260 2261

	/*	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.
2262
	 *	We use a 1 minute timeout (about the same as BSD) then kill
L
Linus Torvalds 已提交
2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277
	 *	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);
2278
			__NET_INC_STATS(sock_net(sk),
2279
					LINUX_MIB_TCPABORTONLINGER);
L
Linus Torvalds 已提交
2280
		} else {
2281
			const int tmo = tcp_fin_time(sk);
L
Linus Torvalds 已提交
2282 2283

			if (tmo > TCP_TIMEWAIT_LEN) {
2284 2285
				inet_csk_reset_keepalive_timer(sk,
						tmo - TCP_TIMEWAIT_LEN);
L
Linus Torvalds 已提交
2286 2287 2288 2289 2290 2291 2292
			} else {
				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
				goto out;
			}
		}
	}
	if (sk->sk_state != TCP_CLOSE) {
2293
		sk_mem_reclaim(sk);
A
Arun Sharma 已提交
2294
		if (tcp_check_oom(sk, 0)) {
L
Linus Torvalds 已提交
2295 2296
			tcp_set_state(sk, TCP_CLOSE);
			tcp_send_active_reset(sk, GFP_ATOMIC);
2297
			__NET_INC_STATS(sock_net(sk),
2298
					LINUX_MIB_TCPABORTONMEMORY);
L
Linus Torvalds 已提交
2299 2300 2301
		}
	}

2302 2303 2304 2305 2306 2307
	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.
		 */
2308
		if (req)
2309
			reqsk_fastopen_remove(sk, req, false);
2310
		inet_csk_destroy_sock(sk);
2311
	}
L
Linus Torvalds 已提交
2312 2313 2314 2315 2316 2317 2318
	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}
E
Eric Dumazet 已提交
2319
EXPORT_SYMBOL(tcp_close);
L
Linus Torvalds 已提交
2320 2321 2322

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

E
Eric Dumazet 已提交
2323
static inline bool tcp_need_reset(int state)
L
Linus Torvalds 已提交
2324 2325 2326 2327 2328 2329
{
	return (1 << state) &
	       (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
		TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
}

2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345
static void tcp_rtx_queue_purge(struct sock *sk)
{
	struct rb_node *p = rb_first(&sk->tcp_rtx_queue);

	while (p) {
		struct sk_buff *skb = rb_to_skb(p);

		p = rb_next(p);
		/* Since we are deleting whole queue, no need to
		 * list_del(&skb->tcp_tsorted_anchor)
		 */
		tcp_rtx_queue_unlink(skb, sk);
		sk_wmem_free_skb(sk, skb);
	}
}

2346 2347 2348 2349 2350 2351 2352 2353 2354
void tcp_write_queue_purge(struct sock *sk)
{
	struct sk_buff *skb;

	tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
	while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL) {
		tcp_skb_tsorted_anchor_cleanup(skb);
		sk_wmem_free_skb(sk, skb);
	}
2355
	tcp_rtx_queue_purge(sk);
2356 2357 2358 2359 2360
	INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
	sk_mem_reclaim(sk);
	tcp_clear_all_retrans_hints(tcp_sk(sk));
}

L
Linus Torvalds 已提交
2361 2362 2363
int tcp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
2364
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2365 2366 2367 2368 2369 2370 2371 2372 2373
	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) {
2374
		inet_csk_listen_stop(sk);
P
Pavel Emelyanov 已提交
2375 2376
	} else if (unlikely(tp->repair)) {
		sk->sk_err = ECONNABORTED;
L
Linus Torvalds 已提交
2377 2378 2379
	} 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
2380
		/* The last check adjusts for discrepancy of Linux wrt. RFC
L
Linus Torvalds 已提交
2381 2382 2383 2384 2385 2386 2387 2388 2389
		 * 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);
2390
	tcp_write_queue_purge(sk);
2391
	tcp_fastopen_active_disable_ofo_check(sk);
2392
	skb_rbtree_purge(&tp->out_of_order_queue);
L
Linus Torvalds 已提交
2393

E
Eric Dumazet 已提交
2394
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
2395 2396 2397 2398 2399 2400

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

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);
2401
	tp->srtt_us = 0;
2402 2403
	tp->write_seq += tp->max_window + 2;
	if (tp->write_seq == 0)
L
Linus Torvalds 已提交
2404
		tp->write_seq = 1;
2405
	icsk->icsk_backoff = 0;
L
Linus Torvalds 已提交
2406
	tp->snd_cwnd = 2;
2407
	icsk->icsk_probes_out = 0;
L
Linus Torvalds 已提交
2408
	tp->packets_out = 0;
I
Ilpo Järvinen 已提交
2409
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
L
Linus Torvalds 已提交
2410
	tp->snd_cwnd_cnt = 0;
2411
	tp->window_clamp = 0;
2412
	tcp_set_ca_state(sk, TCP_CA_Open);
L
Linus Torvalds 已提交
2413
	tcp_clear_retrans(tp);
2414
	inet_csk_delack_init(sk);
2415 2416 2417 2418
	/* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0
	 * issue in __tcp_select_window()
	 */
	icsk->icsk_ack.rcv_mss = TCP_MIN_MSS;
2419
	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
L
Linus Torvalds 已提交
2420
	__sk_dst_reset(sk);
2421 2422
	dst_release(sk->sk_rx_dst);
	sk->sk_rx_dst = NULL;
2423
	tcp_saved_syn_free(tp);
L
Linus Torvalds 已提交
2424

2425 2426 2427 2428
	/* Clean up fastopen related fields */
	tcp_free_fastopen_req(tp);
	inet->defer_connect = 0;

E
Eric Dumazet 已提交
2429
	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
L
Linus Torvalds 已提交
2430 2431 2432 2433

	sk->sk_error_report(sk);
	return err;
}
E
Eric Dumazet 已提交
2434
EXPORT_SYMBOL(tcp_disconnect);
L
Linus Torvalds 已提交
2435

E
Eric Dumazet 已提交
2436
static inline bool tcp_can_repair_sock(const struct sock *sk)
P
Pavel Emelyanov 已提交
2437
{
2438
	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2439
		(sk->sk_state != TCP_LISTEN);
P
Pavel Emelyanov 已提交
2440 2441
}

2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473
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;
}

2474
static int tcp_repair_options_est(struct sock *sk,
2475
		struct tcp_repair_opt __user *optbuf, unsigned int len)
2476
{
2477
	struct tcp_sock *tp = tcp_sk(sk);
2478
	struct tcp_repair_opt opt;
2479

2480 2481
	while (len >= sizeof(opt)) {
		if (copy_from_user(&opt, optbuf, sizeof(opt)))
2482 2483 2484
			return -EFAULT;

		optbuf++;
2485
		len -= sizeof(opt);
2486

2487 2488 2489
		switch (opt.opt_code) {
		case TCPOPT_MSS:
			tp->rx_opt.mss_clamp = opt.opt_val;
2490
			tcp_mtup_init(sk);
2491
			break;
2492
		case TCPOPT_WINDOW:
2493 2494 2495 2496
			{
				u16 snd_wscale = opt.opt_val & 0xFFFF;
				u16 rcv_wscale = opt.opt_val >> 16;

2497
				if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2498
					return -EFBIG;
2499

2500 2501 2502 2503
				tp->rx_opt.snd_wscale = snd_wscale;
				tp->rx_opt.rcv_wscale = rcv_wscale;
				tp->rx_opt.wscale_ok = 1;
			}
2504 2505
			break;
		case TCPOPT_SACK_PERM:
2506 2507 2508
			if (opt.opt_val != 0)
				return -EINVAL;

2509 2510 2511 2512 2513
			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
			if (sysctl_tcp_fack)
				tcp_enable_fack(tp);
			break;
		case TCPOPT_TIMESTAMP:
2514 2515 2516
			if (opt.opt_val != 0)
				return -EINVAL;

2517 2518 2519 2520 2521 2522 2523 2524
			tp->rx_opt.tstamp_ok = 1;
			break;
		}
	}

	return 0;
}

L
Linus Torvalds 已提交
2525 2526 2527
/*
 *	Socket option code for TCP.
 */
2528
static int do_tcp_setsockopt(struct sock *sk, int level,
2529
		int optname, char __user *optval, unsigned int optlen)
L
Linus Torvalds 已提交
2530 2531
{
	struct tcp_sock *tp = tcp_sk(sk);
2532
	struct inet_connection_sock *icsk = inet_csk(sk);
2533
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2534 2535 2536
	int val;
	int err = 0;

2537 2538 2539
	/* These are data/string values, all the others are ints */
	switch (optname) {
	case TCP_CONGESTION: {
2540 2541 2542 2543 2544 2545
		char name[TCP_CA_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
2546
					min_t(long, TCP_CA_NAME_MAX-1, optlen));
2547 2548 2549 2550 2551
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
2552
		err = tcp_set_congestion_control(sk, name, true, true);
2553 2554 2555
		release_sock(sk);
		return err;
	}
D
Dave Watson 已提交
2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573
	case TCP_ULP: {
		char name[TCP_ULP_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
					min_t(long, TCP_ULP_NAME_MAX - 1,
					      optlen));
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
		err = tcp_set_ulp(sk, name);
		release_sock(sk);
		return err;
	}
2574 2575 2576
	default:
		/* fallthru */
		break;
2577
	}
2578

L
Linus Torvalds 已提交
2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590
	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
2591 2592
		 * know which interface is going to be used
		 */
2593
		if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
L
Linus Torvalds 已提交
2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610
			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;
2611
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2612 2613 2614 2615 2616
		} else {
			tp->nonagle &= ~TCP_NAGLE_OFF;
		}
		break;

A
Andreas Petlund 已提交
2617 2618 2619 2620 2621 2622 2623
	case TCP_THIN_LINEAR_TIMEOUTS:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->thin_lto = val;
		break;

A
Andreas Petlund 已提交
2624 2625 2626 2627 2628
	case TCP_THIN_DUPACK:
		if (val < 0 || val > 1)
			err = -EINVAL;
		break;

P
Pavel Emelyanov 已提交
2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664
	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;

2665 2666 2667 2668
	case TCP_REPAIR_OPTIONS:
		if (!tp->repair)
			err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
2669
			err = tcp_repair_options_est(sk,
2670 2671
					(struct tcp_repair_opt __user *)optval,
					optlen);
2672 2673 2674 2675
		else
			err = -EPERM;
		break;

L
Linus Torvalds 已提交
2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693
	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;
2694
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705
		}
		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))) {
2706
				u32 elapsed = keepalive_time_elapsed(tp);
L
Linus Torvalds 已提交
2707 2708 2709 2710
				if (tp->keepalive_time > elapsed)
					elapsed = tp->keepalive_time - elapsed;
				else
					elapsed = 0;
2711
				inet_csk_reset_keepalive_timer(sk, elapsed);
L
Linus Torvalds 已提交
2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730
			}
		}
		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
2731
			icsk->icsk_syn_retries = val;
L
Linus Torvalds 已提交
2732 2733
		break;

2734 2735 2736 2737 2738 2739 2740
	case TCP_SAVE_SYN:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->save_syn = val;
		break;

L
Linus Torvalds 已提交
2741 2742 2743
	case TCP_LINGER2:
		if (val < 0)
			tp->linger2 = -1;
2744
		else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
L
Linus Torvalds 已提交
2745 2746 2747 2748 2749 2750
			tp->linger2 = 0;
		else
			tp->linger2 = val * HZ;
		break;

	case TCP_DEFER_ACCEPT:
2751 2752 2753 2754
		/* 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
2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770
		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) {
2771
			icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2772
		} else {
2773
			icsk->icsk_ack.pingpong = 0;
L
Linus Torvalds 已提交
2774 2775
			if ((1 << sk->sk_state) &
			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2776 2777
			    inet_csk_ack_scheduled(sk)) {
				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2778
				tcp_cleanup_rbuf(sk, 1);
L
Linus Torvalds 已提交
2779
				if (!(val & 1))
2780
					icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2781 2782 2783 2784
			}
		}
		break;

2785 2786
#ifdef CONFIG_TCP_MD5SIG
	case TCP_MD5SIG:
2787
	case TCP_MD5SIG_EXT:
2788
		/* Read the IP->Key mappings from userspace */
2789
		err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
2790 2791
		break;
#endif
2792
	case TCP_USER_TIMEOUT:
2793
		/* Cap the max time in ms TCP will retry or probe the window
2794 2795
		 * before giving up and aborting (ETIMEDOUT) a connection.
		 */
2796 2797 2798 2799
		if (val < 0)
			err = -EINVAL;
		else
			icsk->icsk_user_timeout = msecs_to_jiffies(val);
2800
		break;
2801 2802 2803

	case TCP_FASTOPEN:
		if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2804
		    TCPF_LISTEN))) {
2805
			tcp_fastopen_init_key_once(net);
2806

2807
			fastopen_queue_tune(sk, val);
2808
		} else {
2809
			err = -EINVAL;
2810
		}
2811
		break;
W
Wei Wang 已提交
2812 2813 2814
	case TCP_FASTOPEN_CONNECT:
		if (val > 1 || val < 0) {
			err = -EINVAL;
2815
		} else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
W
Wei Wang 已提交
2816 2817 2818 2819 2820 2821 2822 2823
			if (sk->sk_state == TCP_CLOSE)
				tp->fastopen_connect = val;
			else
				err = -EINVAL;
		} else {
			err = -EOPNOTSUPP;
		}
		break;
2824 2825 2826 2827
	case TCP_TIMESTAMP:
		if (!tp->repair)
			err = -EPERM;
		else
2828
			tp->tsoffset = val - tcp_time_stamp_raw();
2829
		break;
2830 2831 2832
	case TCP_REPAIR_WINDOW:
		err = tcp_repair_set_window(tp, optval, optlen);
		break;
2833 2834 2835 2836
	case TCP_NOTSENT_LOWAT:
		tp->notsent_lowat = val;
		sk->sk_write_space(sk);
		break;
L
Linus Torvalds 已提交
2837 2838 2839
	default:
		err = -ENOPROTOOPT;
		break;
2840 2841
	}

L
Linus Torvalds 已提交
2842 2843 2844 2845
	release_sock(sk);
	return err;
}

2846
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2847
		   unsigned int optlen)
2848
{
2849
	const struct inet_connection_sock *icsk = inet_csk(sk);
2850 2851 2852 2853 2854 2855

	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
2856
EXPORT_SYMBOL(tcp_setsockopt);
2857 2858

#ifdef CONFIG_COMPAT
2859
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2860
			  char __user *optval, unsigned int optlen)
2861
{
2862 2863 2864
	if (level != SOL_TCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
2865 2866
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
2867
EXPORT_SYMBOL(compat_tcp_setsockopt);
2868 2869
#endif

2870 2871 2872 2873 2874 2875 2876 2877 2878
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)
2879
			stats[i] += tcp_jiffies32 - tp->chrono_start;
2880 2881 2882 2883 2884 2885 2886 2887 2888
		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
2889
/* Return information about state of tcp endpoint in API format. */
2890
void tcp_get_info(struct sock *sk, struct tcp_info *info)
L
Linus Torvalds 已提交
2891
{
2892
	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
2893
	const struct inet_connection_sock *icsk = inet_csk(sk);
2894
	u32 now;
2895
	u64 rate64;
2896
	bool slow;
2897
	u32 rate;
L
Linus Torvalds 已提交
2898 2899

	memset(info, 0, sizeof(*info));
2900 2901
	if (sk->sk_type != SOCK_STREAM)
		return;
L
Linus Torvalds 已提交
2902

2903 2904
	info->tcpi_state = sk_state_load(sk);

2905 2906 2907
	/* Report meaningful fields for all TCP states, including listeners */
	rate = READ_ONCE(sk->sk_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2908
	info->tcpi_pacing_rate = rate64;
2909 2910 2911

	rate = READ_ONCE(sk->sk_max_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2912
	info->tcpi_max_pacing_rate = rate64;
2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925

	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;
	}
2926 2927 2928

	slow = lock_sock_fast(sk);

2929
	info->tcpi_ca_state = icsk->icsk_ca_state;
2930
	info->tcpi_retransmits = icsk->icsk_retransmits;
2931
	info->tcpi_probes = icsk->icsk_probes_out;
2932
	info->tcpi_backoff = icsk->icsk_backoff;
L
Linus Torvalds 已提交
2933 2934 2935

	if (tp->rx_opt.tstamp_ok)
		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2936
	if (tcp_is_sack(tp))
L
Linus Torvalds 已提交
2937 2938 2939 2940 2941
		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;
2942
	}
L
Linus Torvalds 已提交
2943

E
Eric Dumazet 已提交
2944
	if (tp->ecn_flags & TCP_ECN_OK)
L
Linus Torvalds 已提交
2945
		info->tcpi_options |= TCPI_OPT_ECN;
E
Eric Dumazet 已提交
2946 2947
	if (tp->ecn_flags & TCP_ECN_SEEN)
		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Y
Yuchung Cheng 已提交
2948 2949
	if (tp->syn_data_acked)
		info->tcpi_options |= TCPI_OPT_SYN_DATA;
L
Linus Torvalds 已提交
2950

2951 2952
	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2953
	info->tcpi_snd_mss = tp->mss_cache;
2954
	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
L
Linus Torvalds 已提交
2955

2956 2957 2958
	info->tcpi_unacked = tp->packets_out;
	info->tcpi_sacked = tp->sacked_out;

L
Linus Torvalds 已提交
2959 2960 2961 2962
	info->tcpi_lost = tp->lost_out;
	info->tcpi_retrans = tp->retrans_out;
	info->tcpi_fackets = tp->fackets_out;

2963
	now = tcp_jiffies32;
L
Linus Torvalds 已提交
2964
	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2965
	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
L
Linus Torvalds 已提交
2966 2967
	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);

2968
	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
L
Linus Torvalds 已提交
2969
	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2970 2971
	info->tcpi_rtt = tp->srtt_us >> 3;
	info->tcpi_rttvar = tp->mdev_us >> 2;
L
Linus Torvalds 已提交
2972 2973 2974
	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
	info->tcpi_advmss = tp->advmss;

2975
	info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
L
Linus Torvalds 已提交
2976 2977 2978
	info->tcpi_rcv_space = tp->rcvq_space.space;

	info->tcpi_total_retrans = tp->total_retrans;
2979

2980 2981
	info->tcpi_bytes_acked = tp->bytes_acked;
	info->tcpi_bytes_received = tp->bytes_received;
2982
	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
2983
	tcp_get_info_chrono_stats(tp, info);
2984

2985 2986
	info->tcpi_segs_out = tp->segs_out;
	info->tcpi_segs_in = tp->segs_in;
2987 2988

	info->tcpi_min_rtt = tcp_min_rtt(tp);
2989 2990
	info->tcpi_data_segs_in = tp->data_segs_in;
	info->tcpi_data_segs_out = tp->data_segs_out;
Y
Yuchung Cheng 已提交
2991 2992

	info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
2993 2994
	rate64 = tcp_compute_delivery_rate(tp);
	if (rate64)
2995
		info->tcpi_delivery_rate = rate64;
2996
	unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
2997 2998 2999
}
EXPORT_SYMBOL_GPL(tcp_get_info);

3000 3001 3002 3003 3004
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;
3005 3006
	u64 rate64;
	u32 rate;
3007

3008 3009 3010
	stats = alloc_skb(7 * nla_total_size_64bit(sizeof(u64)) +
			  3 * nla_total_size(sizeof(u32)) +
			  2 * nla_total_size(sizeof(u8)), GFP_ATOMIC);
3011 3012 3013 3014 3015 3016 3017 3018 3019 3020
	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);
3021 3022 3023 3024
	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);
3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038

	rate = READ_ONCE(sk->sk_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
	nla_put_u64_64bit(stats, TCP_NLA_PACING_RATE, rate64, TCP_NLA_PAD);

	rate64 = tcp_compute_delivery_rate(tp);
	nla_put_u64_64bit(stats, TCP_NLA_DELIVERY_RATE, rate64, TCP_NLA_PAD);

	nla_put_u32(stats, TCP_NLA_SND_CWND, tp->snd_cwnd);
	nla_put_u32(stats, TCP_NLA_REORDERING, tp->reordering);
	nla_put_u32(stats, TCP_NLA_MIN_RTT, tcp_min_rtt(tp));

	nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits);
	nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited);
3039 3040 3041
	return stats;
}

3042 3043
static int do_tcp_getsockopt(struct sock *sk, int level,
		int optname, char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
3044
{
3045
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
3046
	struct tcp_sock *tp = tcp_sk(sk);
3047
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059
	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:
3060
		val = tp->mss_cache;
L
Linus Torvalds 已提交
3061 3062
		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			val = tp->rx_opt.user_mss;
3063 3064
		if (tp->repair)
			val = tp->rx_opt.mss_clamp;
L
Linus Torvalds 已提交
3065 3066 3067 3068 3069 3070 3071 3072
		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
3073
		val = keepalive_time_when(tp) / HZ;
L
Linus Torvalds 已提交
3074 3075
		break;
	case TCP_KEEPINTVL:
E
Eric Dumazet 已提交
3076
		val = keepalive_intvl_when(tp) / HZ;
L
Linus Torvalds 已提交
3077 3078
		break;
	case TCP_KEEPCNT:
E
Eric Dumazet 已提交
3079
		val = keepalive_probes(tp);
L
Linus Torvalds 已提交
3080 3081
		break;
	case TCP_SYNCNT:
3082
		val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
L
Linus Torvalds 已提交
3083 3084 3085 3086
		break;
	case TCP_LINGER2:
		val = tp->linger2;
		if (val >= 0)
3087
			val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
L
Linus Torvalds 已提交
3088 3089
		break;
	case TCP_DEFER_ACCEPT:
3090 3091
		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
3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110
		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;
	}
3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130
	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
3131
	case TCP_QUICKACK:
3132
		val = !icsk->icsk_ack.pingpong;
L
Linus Torvalds 已提交
3133
		break;
3134 3135 3136 3137 3138 3139 3140

	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;
3141
		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
3142 3143
			return -EFAULT;
		return 0;
3144

D
Dave Watson 已提交
3145 3146 3147 3148
	case TCP_ULP:
		if (get_user(len, optlen))
			return -EFAULT;
		len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
3149 3150 3151 3152 3153
		if (!icsk->icsk_ulp_ops) {
			if (put_user(0, optlen))
				return -EFAULT;
			return 0;
		}
D
Dave Watson 已提交
3154 3155 3156 3157 3158 3159
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len))
			return -EFAULT;
		return 0;

3160 3161 3162
	case TCP_THIN_LINEAR_TIMEOUTS:
		val = tp->thin_lto;
		break;
Y
Yuchung Cheng 已提交
3163

3164
	case TCP_THIN_DUPACK:
Y
Yuchung Cheng 已提交
3165
		val = 0;
3166
		break;
3167

P
Pavel Emelyanov 已提交
3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178
	case TCP_REPAIR:
		val = tp->repair;
		break;

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

3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200
	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
3201 3202 3203 3204 3205 3206 3207 3208 3209
	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;

3210 3211 3212
	case TCP_USER_TIMEOUT:
		val = jiffies_to_msecs(icsk->icsk_user_timeout);
		break;
3213 3214

	case TCP_FASTOPEN:
3215
		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3216 3217
		break;

W
Wei Wang 已提交
3218 3219 3220 3221
	case TCP_FASTOPEN_CONNECT:
		val = tp->fastopen_connect;
		break;

3222
	case TCP_TIMESTAMP:
3223
		val = tcp_time_stamp_raw() + tp->tsoffset;
3224
		break;
3225 3226 3227
	case TCP_NOTSENT_LOWAT:
		val = tp->notsent_lowat;
		break;
3228 3229 3230 3231 3232 3233 3234 3235 3236
	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) {
3237 3238 3239 3240 3241 3242 3243 3244 3245
			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];
3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263
			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
3264 3265
	default:
		return -ENOPROTOOPT;
3266
	}
L
Linus Torvalds 已提交
3267 3268 3269 3270 3271 3272 3273 3274

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

3275 3276 3277 3278 3279 3280 3281 3282 3283 3284
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
3285
EXPORT_SYMBOL(tcp_getsockopt);
3286 3287

#ifdef CONFIG_COMPAT
3288 3289
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
			  char __user *optval, int __user *optlen)
3290
{
3291 3292 3293
	if (level != SOL_TCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
3294 3295
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
3296
EXPORT_SYMBOL(compat_tcp_getsockopt);
3297
#endif
L
Linus Torvalds 已提交
3298

3299
#ifdef CONFIG_TCP_MD5SIG
E
Eric Dumazet 已提交
3300
static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3301
static DEFINE_MUTEX(tcp_md5sig_mutex);
E
Eric Dumazet 已提交
3302
static bool tcp_md5sig_pool_populated = false;
3303

3304
static void __tcp_alloc_md5sig_pool(void)
3305
{
H
Herbert Xu 已提交
3306
	struct crypto_ahash *hash;
3307 3308
	int cpu;

H
Herbert Xu 已提交
3309
	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3310
	if (IS_ERR(hash))
H
Herbert Xu 已提交
3311 3312
		return;

3313
	for_each_possible_cpu(cpu) {
3314
		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
H
Herbert Xu 已提交
3315
		struct ahash_request *req;
3316

3317 3318 3319 3320 3321 3322 3323 3324 3325
		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
3326 3327 3328 3329 3330 3331 3332 3333 3334 3335
		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;
3336
	}
E
Eric Dumazet 已提交
3337 3338
	/* before setting tcp_md5sig_pool_populated, we must commit all writes
	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3339 3340
	 */
	smp_wmb();
E
Eric Dumazet 已提交
3341
	tcp_md5sig_pool_populated = true;
3342 3343
}

3344
bool tcp_alloc_md5sig_pool(void)
3345
{
E
Eric Dumazet 已提交
3346
	if (unlikely(!tcp_md5sig_pool_populated)) {
3347 3348
		mutex_lock(&tcp_md5sig_mutex);

E
Eric Dumazet 已提交
3349
		if (!tcp_md5sig_pool_populated)
3350 3351 3352
			__tcp_alloc_md5sig_pool();

		mutex_unlock(&tcp_md5sig_mutex);
3353
	}
E
Eric Dumazet 已提交
3354
	return tcp_md5sig_pool_populated;
3355 3356 3357
}
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);

E
Eric Dumazet 已提交
3358 3359 3360 3361 3362 3363 3364 3365 3366

/**
 *	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)
3367
{
E
Eric Dumazet 已提交
3368
	local_bh_disable();
3369

E
Eric Dumazet 已提交
3370 3371 3372 3373 3374
	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
3375 3376 3377 3378
	local_bh_enable();
	return NULL;
}
EXPORT_SYMBOL(tcp_get_md5sig_pool);
3379

3380
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3381
			  const struct sk_buff *skb, unsigned int header_len)
3382 3383 3384
{
	struct scatterlist sg;
	const struct tcphdr *tp = tcp_hdr(skb);
H
Herbert Xu 已提交
3385
	struct ahash_request *req = hp->md5_req;
3386 3387 3388
	unsigned int i;
	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
					   skb_headlen(skb) - header_len : 0;
3389
	const struct skb_shared_info *shi = skb_shinfo(skb);
3390
	struct sk_buff *frag_iter;
3391 3392 3393 3394

	sg_init_table(&sg, 1);

	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
H
Herbert Xu 已提交
3395 3396
	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
	if (crypto_ahash_update(req))
3397 3398 3399 3400
		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
3401 3402 3403 3404 3405
		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
3406 3407
		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
		if (crypto_ahash_update(req))
3408 3409 3410
			return 1;
	}

3411 3412 3413 3414
	skb_walk_frags(skb, frag_iter)
		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
			return 1;

3415 3416 3417 3418
	return 0;
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

3419
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3420 3421 3422 3423
{
	struct scatterlist sg;

	sg_init_one(&sg, key->key, key->keylen);
H
Herbert Xu 已提交
3424 3425
	ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
	return crypto_ahash_update(hp->md5_req);
3426 3427 3428
}
EXPORT_SYMBOL(tcp_md5_hash_key);

3429 3430
#endif

A
Andi Kleen 已提交
3431 3432
void tcp_done(struct sock *sk)
{
3433 3434
	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;

3435
	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3436
		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
A
Andi Kleen 已提交
3437 3438 3439

	tcp_set_state(sk, TCP_CLOSE);
	tcp_clear_xmit_timers(sk);
3440
	if (req)
3441
		reqsk_fastopen_remove(sk, req, false);
A
Andi Kleen 已提交
3442 3443 3444 3445 3446 3447 3448 3449 3450 3451

	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);

3452 3453 3454
int tcp_abort(struct sock *sk, int err)
{
	if (!sk_fullsock(sk)) {
3455 3456 3457 3458 3459 3460 3461 3462 3463
		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;
		}
3464 3465 3466 3467 3468 3469
		return -EOPNOTSUPP;
	}

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

3470 3471 3472 3473 3474
	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);
		inet_csk_listen_stop(sk);
	}

3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495
	/* 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);

3496
extern struct tcp_congestion_ops tcp_reno;
L
Linus Torvalds 已提交
3497 3498 3499 3500

static __initdata unsigned long thash_entries;
static int __init set_thash_entries(char *str)
{
3501 3502
	ssize_t ret;

L
Linus Torvalds 已提交
3503 3504
	if (!str)
		return 0;
3505 3506 3507 3508 3509

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

L
Linus Torvalds 已提交
3510 3511 3512 3513
	return 1;
}
__setup("thash_entries=", set_thash_entries);

F
Fabian Frederick 已提交
3514
static void __init tcp_init_mem(void)
3515
{
E
Eric Dumazet 已提交
3516 3517
	unsigned long limit = nr_free_buffer_pages() / 16;

3518
	limit = max(limit, 128UL);
E
Eric Dumazet 已提交
3519 3520 3521
	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 % */
3522 3523
}

L
Linus Torvalds 已提交
3524 3525
void __init tcp_init(void)
{
3526
	int max_rshare, max_wshare, cnt;
3527
	unsigned long limit;
3528
	unsigned int i;
L
Linus Torvalds 已提交
3529

3530 3531
	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
L
Linus Torvalds 已提交
3532

3533 3534
	percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
	percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3535
	inet_hashinfo_init(&tcp_hashinfo);
3536 3537 3538
	tcp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("tcp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
3539
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
3540 3541 3542 3543 3544 3545

	/* Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
3546
	tcp_hashinfo.ehash =
L
Linus Torvalds 已提交
3547
		alloc_large_system_hash("TCP established",
3548
					sizeof(struct inet_ehash_bucket),
L
Linus Torvalds 已提交
3549
					thash_entries,
E
Eric Dumazet 已提交
3550
					17, /* one slot per 128 KB of memory */
3551
					0,
L
Linus Torvalds 已提交
3552
					NULL,
3553
					&tcp_hashinfo.ehash_mask,
3554
					0,
3555
					thash_entries ? 0 : 512 * 1024);
E
Eric Dumazet 已提交
3556
	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3557
		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
E
Eric Dumazet 已提交
3558

3559 3560
	if (inet_ehash_locks_alloc(&tcp_hashinfo))
		panic("TCP: failed to alloc ehash_locks");
3561
	tcp_hashinfo.bhash =
L
Linus Torvalds 已提交
3562
		alloc_large_system_hash("TCP bind",
3563
					sizeof(struct inet_bind_hashbucket),
3564
					tcp_hashinfo.ehash_mask + 1,
E
Eric Dumazet 已提交
3565
					17, /* one slot per 128 KB of memory */
3566
					0,
3567
					&tcp_hashinfo.bhash_size,
L
Linus Torvalds 已提交
3568
					NULL,
3569
					0,
L
Linus Torvalds 已提交
3570
					64 * 1024);
3571
	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3572 3573 3574
	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
3575 3576
	}

E
Eric Dumazet 已提交
3577 3578 3579

	cnt = tcp_hashinfo.ehash_mask + 1;
	sysctl_tcp_max_orphans = cnt / 2;
L
Linus Torvalds 已提交
3580

3581
	tcp_init_mem();
3582
	/* Set per-socket limits to no more than 1/128 the pressure threshold */
E
Eric Dumazet 已提交
3583
	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3584 3585
	max_wshare = min(4UL*1024*1024, limit);
	max_rshare = min(6UL*1024*1024, limit);
3586

3587
	sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3588
	sysctl_tcp_wmem[1] = 16*1024;
3589
	sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
3590

3591
	sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3592
	sysctl_tcp_rmem[1] = 87380;
3593
	sysctl_tcp_rmem[2] = max(87380, max_rshare);
L
Linus Torvalds 已提交
3594

3595
	pr_info("Hash tables configured (established %u bind %u)\n",
J
Joe Perches 已提交
3596
		tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3597

3598
	tcp_v4_init();
3599
	tcp_metrics_init();
3600
	BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
E
Eric Dumazet 已提交
3601
	tcp_tasklet_init();
L
Linus Torvalds 已提交
3602
}