tcp.c 93.4 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 <linux/static_key.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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#include <trace/events/tcp.h>

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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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#if IS_ENABLED(CONFIG_SMC)
DEFINE_STATIC_KEY_FALSE(tcp_have_smc);
EXPORT_SYMBOL(tcp_have_smc);
#endif

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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
546
	 * why POLLHUP is incompatible with POLLOUT.	--ANK
L
Linus Torvalds 已提交
547 548 549 550
	 *
	 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
	 * blocking on fresh not-connected or disconnected socket. --ANK
	 */
551
	if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
L
Linus Torvalds 已提交
552 553
		mask |= POLLHUP;
	if (sk->sk_shutdown & RCV_SHUTDOWN)
554
		mask |= POLLIN | POLLRDNORM | POLLRDHUP;
L
Linus Torvalds 已提交
555

556
	/* Connected or passive Fast Open socket? */
557 558
	if (state != TCP_SYN_SENT &&
	    (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
559 560 561 562 563
		int target = sock_rcvlowat(sk, 0, INT_MAX);

		if (tp->urg_seq == tp->copied_seq &&
		    !sock_flag(sk, SOCK_URGINLINE) &&
		    tp->urg_data)
564
			target++;
565 566

		if (tp->rcv_nxt - tp->copied_seq >= target)
L
Linus Torvalds 已提交
567 568 569
			mask |= POLLIN | POLLRDNORM;

		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
570
			if (sk_stream_is_writeable(sk)) {
L
Linus Torvalds 已提交
571 572
				mask |= POLLOUT | POLLWRNORM;
			} else {  /* send SIGIO later */
573
				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
574 575 576 577
				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);

				/* Race breaker. If space is freed after
				 * wspace test but before the flags are set,
578 579
				 * IO signal will be lost. Memory barrier
				 * pairs with the input side.
L
Linus Torvalds 已提交
580
				 */
581
				smp_mb__after_atomic();
582
				if (sk_stream_is_writeable(sk))
L
Linus Torvalds 已提交
583 584
					mask |= POLLOUT | POLLWRNORM;
			}
585 586
		} else
			mask |= POLLOUT | POLLWRNORM;
L
Linus Torvalds 已提交
587 588 589

		if (tp->urg_data & TCP_URG_VALID)
			mask |= POLLPRI;
590
	} else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
W
Wei Wang 已提交
591 592 593 594 595
		/* 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
596
	}
T
Tom Marshall 已提交
597 598
	/* This barrier is coupled with smp_wmb() in tcp_reset() */
	smp_rmb();
599
	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
T
Tom Marshall 已提交
600 601
		mask |= POLLERR;

L
Linus Torvalds 已提交
602 603
	return mask;
}
E
Eric Dumazet 已提交
604
EXPORT_SYMBOL(tcp_poll);
L
Linus Torvalds 已提交
605 606 607 608 609

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
610
	bool slow;
L
Linus Torvalds 已提交
611 612 613 614 615 616

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

E
Eric Dumazet 已提交
617
		slow = lock_sock_fast(sk);
618
		answ = tcp_inq(sk);
E
Eric Dumazet 已提交
619
		unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
620 621 622 623 624 625 626 627 628 629 630 631 632
		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;
633 634 635 636 637 638 639 640 641
	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
642 643
	default:
		return -ENOIOCTLCMD;
644
	}
L
Linus Torvalds 已提交
645 646 647

	return put_user(answ, (int __user *)arg);
}
E
Eric Dumazet 已提交
648
EXPORT_SYMBOL(tcp_ioctl);
L
Linus Torvalds 已提交
649 650 651

static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
{
E
Eric Dumazet 已提交
652
	TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
L
Linus Torvalds 已提交
653 654 655
	tp->pushed_seq = tp->write_seq;
}

E
Eric Dumazet 已提交
656
static inline bool forced_push(const struct tcp_sock *tp)
L
Linus Torvalds 已提交
657 658 659 660
{
	return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
}

661
static void skb_entail(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
662
{
663
	struct tcp_sock *tp = tcp_sk(sk);
664 665 666 667
	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
668
	tcb->tcp_flags = TCPHDR_ACK;
669
	tcb->sacked  = 0;
670
	__skb_header_release(skb);
671
	tcp_add_write_queue_tail(sk, skb);
672 673
	sk->sk_wmem_queued += skb->truesize;
	sk_mem_charge(sk, skb->truesize);
674
	if (tp->nonagle & TCP_NAGLE_PUSH)
675
		tp->nonagle &= ~TCP_NAGLE_PUSH;
676 677

	tcp_slow_start_after_idle_check(sk);
L
Linus Torvalds 已提交
678 679
}

680
static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
L
Linus Torvalds 已提交
681
{
I
Ilpo Järvinen 已提交
682
	if (flags & MSG_OOB)
L
Linus Torvalds 已提交
683 684 685
		tp->snd_up = tp->write_seq;
}

E
Eric Dumazet 已提交
686
/* If a not yet filled skb is pushed, do not send it if
687
 * we have data packets in Qdisc or NIC queues :
E
Eric Dumazet 已提交
688 689 690 691
 * 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
692 693 694
 * 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
695 696 697
 */
static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
				int size_goal)
L
Linus Torvalds 已提交
698
{
E
Eric Dumazet 已提交
699 700
	return skb->len < size_goal &&
	       sysctl_tcp_autocorking &&
701
	       skb != tcp_write_queue_head(sk) &&
702
	       refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
E
Eric Dumazet 已提交
703 704 705 706 707 708 709
}

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;
710

E
Eric Dumazet 已提交
711
	skb = tcp_write_queue_tail(sk);
712 713
	if (!skb)
		return;
E
Eric Dumazet 已提交
714 715 716 717 718 719 720 721
	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 */
722
		if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
E
Eric Dumazet 已提交
723
			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
724
			set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
E
Eric Dumazet 已提交
725
		}
726 727 728
		/* It is possible TX completion already happened
		 * before we set TSQ_THROTTLED.
		 */
729
		if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
730
			return;
L
Linus Torvalds 已提交
731
	}
E
Eric Dumazet 已提交
732 733 734 735 736

	if (flags & MSG_MORE)
		nonagle = TCP_NAGLE_CORK;

	__tcp_push_pending_frames(sk, mss_now, nonagle);
L
Linus Torvalds 已提交
737 738
}

739 740
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
741 742
{
	struct tcp_splice_state *tss = rd_desc->arg.data;
743
	int ret;
J
Jens Axboe 已提交
744

745
	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
A
Al Viro 已提交
746
			      min(rd_desc->count, len), tss->flags);
747 748 749
	if (ret > 0)
		rd_desc->count -= ret;
	return ret;
J
Jens Axboe 已提交
750 751 752 753 754 755 756
}

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,
757
		.count	  = tss->len,
J
Jens Axboe 已提交
758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788
	};

	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;

789
	sock_rps_record_flow(sk);
J
Jens Axboe 已提交
790 791 792 793 794 795 796 797 798 799
	/*
	 * We can't seek on a socket input
	 */
	if (unlikely(*ppos))
		return -ESPIPE;

	ret = spliced = 0;

	lock_sock(sk);

800
	timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
J
Jens Axboe 已提交
801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828
	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;
			}
829 830 831 832 833 834
			/* 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;
835
			sk_wait_data(sk, &timeo, NULL);
J
Jens Axboe 已提交
836 837 838 839 840 841 842 843 844
			if (signal_pending(current)) {
				ret = sock_intr_errno(timeo);
				break;
			}
			continue;
		}
		tss.len -= ret;
		spliced += ret;

845 846
		if (!timeo)
			break;
J
Jens Axboe 已提交
847 848 849 850
		release_sock(sk);
		lock_sock(sk);

		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
851
		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
J
Jens Axboe 已提交
852 853 854 855 856 857 858 859 860 861 862
		    signal_pending(current))
			break;
	}

	release_sock(sk);

	if (spliced)
		return spliced;

	return ret;
}
E
Eric Dumazet 已提交
863
EXPORT_SYMBOL(tcp_splice_read);
J
Jens Axboe 已提交
864

865 866
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
				    bool force_schedule)
867 868 869 870 871 872
{
	struct sk_buff *skb;

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

873 874 875
	if (unlikely(tcp_under_memory_pressure(sk)))
		sk_mem_reclaim_partial(sk);

876
	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
877
	if (likely(skb)) {
878
		bool mem_scheduled;
879

880 881
		if (force_schedule) {
			mem_scheduled = true;
882 883
			sk_forced_mem_schedule(sk, skb->truesize);
		} else {
884
			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
885
		}
886
		if (likely(mem_scheduled)) {
887
			skb_reserve(skb, sk->sk_prot->max_header);
888 889 890 891
			/*
			 * Make sure that we have exactly size bytes
			 * available to the caller, no more, no less.
			 */
E
Eric Dumazet 已提交
892
			skb->reserved_tailroom = skb->end - skb->tail - size;
893
			INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
894 895 896 897
			return skb;
		}
		__kfree_skb(skb);
	} else {
898
		sk->sk_prot->enter_memory_pressure(sk);
899 900 901 902 903
		sk_stream_moderate_sndbuf(sk);
	}
	return NULL;
}

I
Ilpo Järvinen 已提交
904 905 906 907
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
				       int large_allowed)
{
	struct tcp_sock *tp = tcp_sk(sk);
908
	u32 new_size_goal, size_goal;
E
Eric Dumazet 已提交
909 910 911 912

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

913 914
	/* 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
915 916 917 918 919 920 921 922 923
	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
924 925
	}

E
Eric Dumazet 已提交
926
	return max(size_goal, mss_now);
I
Ilpo Järvinen 已提交
927 928 929 930 931 932 933 934 935 936 937 938
}

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;
}

939 940
ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
			 size_t size, int flags)
L
Linus Torvalds 已提交
941 942
{
	struct tcp_sock *tp = tcp_sk(sk);
943
	int mss_now, size_goal;
L
Linus Torvalds 已提交
944 945 946 947
	int err;
	ssize_t copied;
	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

948 949 950 951 952 953
	/* 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)) {
954 955
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
956
			goto out_err;
957
	}
L
Linus Torvalds 已提交
958

959
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
960

I
Ilpo Järvinen 已提交
961
	mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
962 963 964 965
	copied = 0;

	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
966
		goto out_err;
L
Linus Torvalds 已提交
967

968
	while (size > 0) {
969
		struct sk_buff *skb = tcp_write_queue_tail(sk);
970 971
		int copy, i;
		bool can_coalesce;
L
Linus Torvalds 已提交
972

973
		if (!skb || (copy = size_goal - skb->len) <= 0 ||
974
		    !tcp_skb_can_collapse_to(skb)) {
L
Linus Torvalds 已提交
975 976 977 978
new_segment:
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;

979
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
980
					tcp_rtx_and_write_queues_empty(sk));
L
Linus Torvalds 已提交
981 982 983
			if (!skb)
				goto wait_for_memory;

984
			skb_entail(sk, skb);
985
			copy = size_goal;
L
Linus Torvalds 已提交
986 987 988 989 990 991 992
		}

		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
993
		if (!can_coalesce && i >= sysctl_max_skb_frags) {
L
Linus Torvalds 已提交
994 995 996
			tcp_mark_push(tp, skb);
			goto new_segment;
		}
997
		if (!sk_wmem_schedule(sk, copy))
L
Linus Torvalds 已提交
998
			goto wait_for_memory;
999

L
Linus Torvalds 已提交
1000
		if (can_coalesce) {
E
Eric Dumazet 已提交
1001
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
L
Linus Torvalds 已提交
1002 1003 1004 1005
		} else {
			get_page(page);
			skb_fill_page_desc(skb, i, page, offset, copy);
		}
1006
		skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1007

L
Linus Torvalds 已提交
1008 1009 1010 1011
		skb->len += copy;
		skb->data_len += copy;
		skb->truesize += copy;
		sk->sk_wmem_queued += copy;
1012
		sk_mem_charge(sk, copy);
1013
		skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1014 1015
		tp->write_seq += copy;
		TCP_SKB_CB(skb)->end_seq += copy;
1016
		tcp_skb_pcount_set(skb, 0);
L
Linus Torvalds 已提交
1017 1018

		if (!copied)
E
Eric Dumazet 已提交
1019
			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
L
Linus Torvalds 已提交
1020 1021

		copied += copy;
1022
		offset += copy;
1023
		size -= copy;
1024
		if (!size)
L
Linus Torvalds 已提交
1025 1026
			goto out;

1027
		if (skb->len < size_goal || (flags & MSG_OOB))
L
Linus Torvalds 已提交
1028 1029 1030 1031
			continue;

		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
1032
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1033
		} else if (skb == tcp_send_head(sk))
L
Linus Torvalds 已提交
1034 1035 1036 1037 1038 1039
			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
1040 1041
		tcp_push(sk, flags & ~MSG_MORE, mss_now,
			 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1042

1043 1044
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
1045 1046
			goto do_error;

I
Ilpo Järvinen 已提交
1047
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1048 1049 1050
	}

out:
1051
	if (copied) {
E
Eric Dumazet 已提交
1052
		tcp_tx_timestamp(sk, sk->sk_tsflags);
1053 1054 1055
		if (!(flags & MSG_SENDPAGE_NOTLAST))
			tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
	}
L
Linus Torvalds 已提交
1056 1057 1058 1059 1060 1061
	return copied;

do_error:
	if (copied)
		goto out;
out_err:
1062
	/* make sure we wake any epoll edge trigger waiter */
1063 1064
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1065
		sk->sk_write_space(sk);
1066 1067
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1068 1069
	return sk_stream_error(sk, flags, err);
}
1070
EXPORT_SYMBOL_GPL(do_tcp_sendpages);
L
Linus Torvalds 已提交
1071

1072 1073
int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset,
			size_t size, int flags)
L
Linus Torvalds 已提交
1074 1075
{
	if (!(sk->sk_route_caps & NETIF_F_SG) ||
1076
	    !sk_check_csum_caps(sk))
1077
		return sock_no_sendpage_locked(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1078

1079 1080
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1081 1082
	return do_tcp_sendpages(sk, page, offset, size, flags);
}
1083
EXPORT_SYMBOL_GPL(tcp_sendpage_locked);
1084 1085 1086 1087 1088 1089 1090 1091

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
1092
	release_sock(sk);
1093 1094

	return ret;
L
Linus Torvalds 已提交
1095
}
E
Eric Dumazet 已提交
1096
EXPORT_SYMBOL(tcp_sendpage);
L
Linus Torvalds 已提交
1097

1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115
/* 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
1116
{
1117
	const struct tcp_sock *tp = tcp_sk(sk);
1118
	int tmp = tp->mss_cache;
L
Linus Torvalds 已提交
1119

K
Krishna Kumar 已提交
1120
	if (sg) {
1121
		if (sk_can_gso(sk)) {
1122
			tmp = linear_payload_sz(first_skb);
1123
		} else {
1124 1125 1126 1127 1128 1129 1130
			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
1131 1132 1133 1134

	return tmp;
}

1135 1136
void tcp_free_fastopen_req(struct tcp_sock *tp)
{
1137
	if (tp->fastopen_req) {
1138 1139 1140 1141 1142
		kfree(tp->fastopen_req);
		tp->fastopen_req = NULL;
	}
}

1143 1144
static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
				int *copied, size_t size)
1145 1146
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Wei Wang 已提交
1147
	struct inet_sock *inet = inet_sk(sk);
1148
	struct sockaddr *uaddr = msg->msg_name;
1149 1150
	int err, flags;

1151
	if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
1152 1153
	    (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
	     uaddr->sa_family == AF_UNSPEC))
1154
		return -EOPNOTSUPP;
1155
	if (tp->fastopen_req)
1156 1157 1158 1159
		return -EALREADY; /* Another Fast Open is in progress */

	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
				   sk->sk_allocation);
1160
	if (unlikely(!tp->fastopen_req))
1161 1162
		return -ENOBUFS;
	tp->fastopen_req->data = msg;
1163
	tp->fastopen_req->size = size;
1164

W
Wei Wang 已提交
1165 1166 1167 1168 1169 1170 1171 1172 1173
	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;
		}
	}
1174
	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1175
	err = __inet_stream_connect(sk->sk_socket, uaddr,
1176
				    msg->msg_namelen, flags, 1);
1177 1178 1179 1180 1181 1182 1183 1184
	/* 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;
	}
1185 1186 1187
	return err;
}

1188
int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
L
Linus Torvalds 已提交
1189 1190
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Willem de Bruijn 已提交
1191
	struct ubuf_info *uarg = NULL;
L
Linus Torvalds 已提交
1192
	struct sk_buff *skb;
1193
	struct sockcm_cookie sockc;
1194 1195
	int flags, err, copied = 0;
	int mss_now = 0, size_goal, copied_syn = 0;
1196
	bool process_backlog = false;
1197
	bool sg;
L
Linus Torvalds 已提交
1198 1199 1200
	long timeo;

	flags = msg->msg_flags;
W
Willem de Bruijn 已提交
1201 1202 1203 1204 1205 1206 1207

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

1208
		skb = tcp_write_queue_tail(sk);
W
Willem de Bruijn 已提交
1209 1210 1211 1212 1213 1214 1215 1216 1217 1218
		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
1219
	if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect)) {
1220
		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1221 1222 1223 1224 1225 1226
		if (err == -EINPROGRESS && copied_syn > 0)
			goto out;
		else if (err)
			goto out_err;
	}

L
Linus Torvalds 已提交
1227 1228
	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

1229 1230
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1231 1232 1233 1234 1235 1236
	/* 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)) {
1237 1238
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
1239
			goto do_error;
1240
	}
L
Linus Torvalds 已提交
1241

P
Pavel Emelyanov 已提交
1242 1243 1244
	if (unlikely(tp->repair)) {
		if (tp->repair_queue == TCP_RECV_QUEUE) {
			copied = tcp_send_rcvq(sk, msg, size);
1245
			goto out_nopush;
P
Pavel Emelyanov 已提交
1246 1247 1248 1249 1250 1251 1252 1253 1254
		}

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

		/* 'common' sending to sendq */
	}

1255 1256 1257 1258 1259 1260 1261 1262 1263
	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
1264
	/* This should be in poll */
1265
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
1266 1267 1268 1269

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

1270 1271 1272
restart:
	mss_now = tcp_send_mss(sk, &size_goal, flags);

L
Linus Torvalds 已提交
1273 1274
	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1275
		goto do_error;
L
Linus Torvalds 已提交
1276

1277
	sg = !!(sk->sk_route_caps & NETIF_F_SG);
K
Krishna Kumar 已提交
1278

A
Al Viro 已提交
1279
	while (msg_data_left(msg)) {
1280 1281
		int copy = 0;
		int max = size_goal;
L
Linus Torvalds 已提交
1282

1283
		skb = tcp_write_queue_tail(sk);
1284
		if (skb) {
1285 1286 1287
			if (skb->ip_summed == CHECKSUM_NONE)
				max = mss_now;
			copy = max - skb->len;
1288
		}
L
Linus Torvalds 已提交
1289

1290
		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1291 1292
			bool first_skb;

L
Linus Torvalds 已提交
1293
new_segment:
1294 1295 1296 1297 1298
			/* 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
1299

1300 1301
			if (process_backlog && sk_flush_backlog(sk)) {
				process_backlog = false;
1302
				goto restart;
1303
			}
1304
			first_skb = tcp_rtx_and_write_queues_empty(sk);
1305
			skb = sk_stream_alloc_skb(sk,
1306
						  select_size(sk, sg, first_skb),
1307
						  sk->sk_allocation,
1308
						  first_skb);
1309 1310
			if (!skb)
				goto wait_for_memory;
L
Linus Torvalds 已提交
1311

1312
			process_backlog = true;
1313 1314 1315
			/*
			 * Check whether we can use HW checksum.
			 */
1316
			if (sk_check_csum_caps(sk))
1317
				skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1318

1319 1320 1321
			skb_entail(sk, skb);
			copy = size_goal;
			max = size_goal;
1322

1323 1324 1325 1326 1327 1328 1329
			/* 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
1330

1331
		/* Try to append data to the end of skb. */
A
Al Viro 已提交
1332 1333
		if (copy > msg_data_left(msg))
			copy = msg_data_left(msg);
1334 1335 1336 1337 1338 1339 1340 1341

		/* 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
1342
		} else if (!uarg || !uarg->zerocopy) {
1343 1344 1345 1346 1347 1348
			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;
1349

1350 1351
			if (!skb_can_coalesce(skb, i, pfrag->page,
					      pfrag->offset)) {
1352
				if (i >= sysctl_max_skb_frags || !sg) {
1353 1354
					tcp_mark_push(tp, skb);
					goto new_segment;
L
Linus Torvalds 已提交
1355
				}
1356
				merge = false;
L
Linus Torvalds 已提交
1357 1358
			}

1359 1360 1361 1362
			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
1363

1364 1365 1366 1367 1368 1369
			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
1370

1371 1372 1373 1374 1375 1376
			/* 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);
1377
				page_ref_inc(pfrag->page);
1378
			}
1379
			pfrag->offset += copy;
W
Willem de Bruijn 已提交
1380 1381 1382 1383 1384 1385 1386
		} 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;
1387 1388 1389 1390 1391 1392 1393 1394
		}

		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
1395

1396
		copied += copy;
A
Al Viro 已提交
1397
		if (!msg_data_left(msg)) {
1398 1399
			if (unlikely(flags & MSG_EOR))
				TCP_SKB_CB(skb)->eor = 1;
1400 1401
			goto out;
		}
L
Linus Torvalds 已提交
1402

1403
		if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
L
Linus Torvalds 已提交
1404 1405
			continue;

1406 1407 1408 1409 1410 1411 1412
		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
1413
wait_for_sndbuf:
1414
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
L
Linus Torvalds 已提交
1415
wait_for_memory:
1416 1417 1418
		if (copied)
			tcp_push(sk, flags & ~MSG_MORE, mss_now,
				 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1419

1420 1421
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
1422
			goto do_error;
L
Linus Torvalds 已提交
1423

1424
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1425 1426 1427
	}

out:
1428
	if (copied) {
E
Eric Dumazet 已提交
1429
		tcp_tx_timestamp(sk, sockc.tsflags);
E
Eric Dumazet 已提交
1430
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1431
	}
1432
out_nopush:
W
Willem de Bruijn 已提交
1433
	sock_zerocopy_put(uarg);
1434
	return copied + copied_syn;
L
Linus Torvalds 已提交
1435 1436 1437

do_fault:
	if (!skb->len) {
1438 1439 1440 1441 1442
		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);
1443
		sk_wmem_free_skb(sk, skb);
L
Linus Torvalds 已提交
1444 1445 1446
	}

do_error:
1447
	if (copied + copied_syn)
L
Linus Torvalds 已提交
1448 1449
		goto out;
out_err:
W
Willem de Bruijn 已提交
1450
	sock_zerocopy_put_abort(uarg);
L
Linus Torvalds 已提交
1451
	err = sk_stream_error(sk, flags, err);
1452
	/* make sure we wake any epoll edge trigger waiter */
1453 1454
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1455
		sk->sk_write_space(sk);
1456 1457
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1458 1459
	return err;
}
1460
EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471

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
1472
EXPORT_SYMBOL(tcp_sendmsg);
L
Linus Torvalds 已提交
1473 1474 1475 1476 1477 1478

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

1479
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
L
Linus Torvalds 已提交
1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502
{
	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
1503
				err = memcpy_to_msg(msg, &c, 1);
L
Linus Torvalds 已提交
1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522
			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
1523 1524 1525 1526 1527 1528 1529
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 */

1530 1531 1532 1533 1534 1535 1536
	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
1537
	skb_queue_walk(&sk->sk_write_queue, skb) {
1538
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
P
Pavel Emelyanov 已提交
1539 1540 1541 1542 1543 1544 1545 1546 1547
		if (err)
			break;

		copied += skb->len;
	}

	return err ?: copied;
}

L
Linus Torvalds 已提交
1548 1549 1550 1551 1552 1553
/* 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.
 */
1554
static void tcp_cleanup_rbuf(struct sock *sk, int copied)
L
Linus Torvalds 已提交
1555 1556
{
	struct tcp_sock *tp = tcp_sk(sk);
E
Eric Dumazet 已提交
1557
	bool time_to_ack = false;
L
Linus Torvalds 已提交
1558 1559 1560

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

1561
	WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
J
Joe Perches 已提交
1562
	     "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1563
	     tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
L
Linus Torvalds 已提交
1564

1565 1566
	if (inet_csk_ack_scheduled(sk)) {
		const struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1567 1568
		   /* Delayed ACKs frequently hit locked sockets during bulk
		    * receive. */
1569
		if (icsk->icsk_ack.blocked ||
L
Linus Torvalds 已提交
1570
		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
1571
		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
L
Linus Torvalds 已提交
1572 1573 1574 1575 1576 1577
		    /*
		     * 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.
		     */
1578 1579 1580 1581 1582
		    (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
1583
			time_to_ack = true;
L
Linus Torvalds 已提交
1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604
	}

	/* 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
1605
				time_to_ack = true;
L
Linus Torvalds 已提交
1606 1607 1608 1609 1610 1611
		}
	}
	if (time_to_ack)
		tcp_send_ack(sk);
}

1612
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
L
Linus Torvalds 已提交
1613 1614 1615 1616
{
	struct sk_buff *skb;
	u32 offset;

1617
	while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
L
Linus Torvalds 已提交
1618
		offset = seq - TCP_SKB_CB(skb)->seq;
1619 1620
		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
1621
			offset--;
1622
		}
1623
		if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
L
Linus Torvalds 已提交
1624 1625 1626
			*off = offset;
			return skb;
		}
1627 1628 1629 1630
		/* 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
1631
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659
	}
	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) {
1660 1661
			int used;
			size_t len;
L
Linus Torvalds 已提交
1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672

			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);
1673
			if (used <= 0) {
1674 1675 1676 1677
				if (!copied)
					copied = used;
				break;
			} else if (used <= len) {
L
Linus Torvalds 已提交
1678 1679 1680 1681
				seq += used;
				copied += used;
				offset += used;
			}
1682
			/* If recv_actor drops the lock (e.g. TCP splice
1683 1684 1685 1686
			 * receive) the skb pointer might be invalid when
			 * getting here: tcp_collapse might have deleted it
			 * while aggregating skbs from the socket queue.
			 */
1687 1688
			skb = tcp_recv_skb(sk, seq - 1, &offset);
			if (!skb)
L
Linus Torvalds 已提交
1689
				break;
1690 1691 1692 1693 1694
			/* 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
1695
		}
1696
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
D
Dan Williams 已提交
1697
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1698 1699 1700
			++seq;
			break;
		}
D
Dan Williams 已提交
1701
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1702 1703
		if (!desc->count)
			break;
1704
		tp->copied_seq = seq;
L
Linus Torvalds 已提交
1705 1706 1707 1708 1709 1710
	}
	tp->copied_seq = seq;

	tcp_rcv_space_adjust(sk);

	/* Clean up data we have read: This will do ACK frames. */
1711 1712
	if (copied > 0) {
		tcp_recv_skb(sk, seq, &offset);
1713
		tcp_cleanup_rbuf(sk, copied);
1714
	}
L
Linus Torvalds 已提交
1715 1716
	return copied;
}
E
Eric Dumazet 已提交
1717
EXPORT_SYMBOL(tcp_read_sock);
L
Linus Torvalds 已提交
1718

1719 1720 1721 1722 1723 1724
int tcp_peek_len(struct socket *sock)
{
	return tcp_inq(sock->sk);
}
EXPORT_SYMBOL(tcp_peek_len);

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 1774 1775 1776 1777 1778 1779
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
1780 1781 1782 1783 1784 1785 1786 1787
/*
 *	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.
 */

1788 1789
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
1790 1791 1792 1793 1794 1795 1796 1797 1798
{
	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;
1799
	struct sk_buff *skb, *last;
I
Ilpo Järvinen 已提交
1800
	u32 urg_hole = 0;
1801 1802
	struct scm_timestamping tss;
	bool has_tss = false;
L
Linus Torvalds 已提交
1803

1804
	if (unlikely(flags & MSG_ERRQUEUE))
1805
		return inet_recv_error(sk, msg, len, addr_len);
1806

1807 1808 1809
	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
	    (sk->sk_state == TCP_ESTABLISHED))
		sk_busy_loop(sk, nonblock);
1810

L
Linus Torvalds 已提交
1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822
	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
1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837
	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
1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860
	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. */

1861
		last = skb_peek_tail(&sk->sk_receive_queue);
1862
		skb_queue_walk(&sk->sk_receive_queue, skb) {
1863
			last = skb;
L
Linus Torvalds 已提交
1864 1865 1866
			/* Now that we have two receive queues this
			 * shouldn't happen.
			 */
1867
			if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
J
Joe Perches 已提交
1868 1869 1870
				 "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
1871
				break;
1872

L
Linus Torvalds 已提交
1873
			offset = *seq - TCP_SKB_CB(skb)->seq;
1874 1875
			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
1876
				offset--;
1877
			}
L
Linus Torvalds 已提交
1878 1879
			if (offset < skb->len)
				goto found_ok_skb;
1880
			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1881
				goto found_fin_ok;
J
Joe Perches 已提交
1882 1883 1884
			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);
1885
		}
L
Linus Torvalds 已提交
1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896

		/* 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 ||
1897
			    signal_pending(current))
L
Linus Torvalds 已提交
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 1927 1928 1929 1930 1931 1932
				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;
			}
		}

1933
		tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1934 1935 1936 1937 1938

		if (copied >= target) {
			/* Do not sleep, just process backlog. */
			release_sock(sk);
			lock_sock(sk);
1939 1940 1941
		} else {
			sk_wait_data(sk, &timeo, last);
		}
L
Linus Torvalds 已提交
1942

I
Ilpo Järvinen 已提交
1943 1944
		if ((flags & MSG_PEEK) &&
		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
1945 1946 1947
			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
1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964
			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
1965
						urg_hole++;
L
Linus Torvalds 已提交
1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976
						offset++;
						used--;
						if (!used)
							goto skip_copy;
					}
				} else
					used = urg_offset;
			}
		}

		if (!(flags & MSG_TRUNC)) {
1977
			err = skb_copy_datagram_msg(skb, offset, msg, used);
D
Dan Williams 已提交
1978 1979 1980 1981 1982
			if (err) {
				/* Exception. Bailout! */
				if (!copied)
					copied = -EFAULT;
				break;
L
Linus Torvalds 已提交
1983 1984 1985 1986 1987 1988 1989 1990 1991 1992
			}
		}

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

		tcp_rcv_space_adjust(sk);

skip_copy:
1993
		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
L
Linus Torvalds 已提交
1994
			tp->urg_data = 0;
1995 1996
			tcp_fast_path_check(sk);
		}
L
Linus Torvalds 已提交
1997 1998 1999
		if (used + offset < skb->len)
			continue;

2000 2001 2002 2003
		if (TCP_SKB_CB(skb)->has_rxtstamp) {
			tcp_update_recv_tstamps(skb, &tss);
			has_tss = true;
		}
2004
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
2005
			goto found_fin_ok;
D
Dan Williams 已提交
2006 2007
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
2008 2009 2010 2011 2012
		continue;

	found_fin_ok:
		/* Process the FIN. */
		++*seq;
D
Dan Williams 已提交
2013 2014
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
2015 2016 2017 2018 2019 2020 2021
		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
	 */

2022 2023 2024
	if (has_tss)
		tcp_recv_timestamp(msg, sk, &tss);

L
Linus Torvalds 已提交
2025
	/* Clean up data we have read: This will do ACK frames. */
2026
	tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
2027 2028 2029 2030 2031 2032 2033 2034 2035

	release_sock(sk);
	return copied;

out:
	release_sock(sk);
	return err;

recv_urg:
2036
	err = tcp_recv_urg(sk, msg, len, flags);
L
Linus Torvalds 已提交
2037
	goto out;
P
Pavel Emelyanov 已提交
2038 2039 2040 2041

recv_sndq:
	err = tcp_peek_sndq(sk, msg, len);
	goto out;
L
Linus Torvalds 已提交
2042
}
E
Eric Dumazet 已提交
2043
EXPORT_SYMBOL(tcp_recvmsg);
L
Linus Torvalds 已提交
2044

I
Ilpo Järvinen 已提交
2045 2046 2047 2048
void tcp_set_state(struct sock *sk, int state)
{
	int oldstate = sk->sk_state;

2049 2050
	trace_tcp_set_state(sk, oldstate, state);

I
Ilpo Järvinen 已提交
2051 2052 2053
	switch (state) {
	case TCP_ESTABLISHED:
		if (oldstate != TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2054
			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2055 2056 2057 2058
		break;

	case TCP_CLOSE:
		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2059
			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
I
Ilpo Järvinen 已提交
2060 2061 2062 2063

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2064
			inet_put_port(sk);
I
Ilpo Järvinen 已提交
2065 2066
		/* fall through */
	default:
2067
		if (oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2068
			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2069 2070 2071 2072 2073
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
2074
	sk_state_store(sk, state);
I
Ilpo Järvinen 已提交
2075 2076

#ifdef STATE_TRACE
2077
	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
I
Ilpo Järvinen 已提交
2078 2079 2080 2081
#endif
}
EXPORT_SYMBOL_GPL(tcp_set_state);

L
Linus Torvalds 已提交
2082 2083 2084 2085 2086 2087 2088
/*
 *	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.
 */

2089
static const unsigned char new_state[16] = {
L
Linus Torvalds 已提交
2090
  /* current state:        new state:      action:	*/
2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103
  [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
2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117
};

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
2118
 *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
L
Linus Torvalds 已提交
2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138
 */

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
2139
EXPORT_SYMBOL(tcp_shutdown);
L
Linus Torvalds 已提交
2140

A
Arun Sharma 已提交
2141 2142 2143 2144 2145 2146 2147
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);

2148 2149 2150 2151
	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
2152 2153 2154
	return too_many_orphans || out_of_socket_memory;
}

L
Linus Torvalds 已提交
2155 2156 2157 2158
void tcp_close(struct sock *sk, long timeout)
{
	struct sk_buff *skb;
	int data_was_unread = 0;
H
Herbert Xu 已提交
2159
	int state;
L
Linus Torvalds 已提交
2160 2161 2162 2163 2164 2165 2166 2167

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

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

		/* Special case. */
2168
		inet_csk_listen_stop(sk);
L
Linus Torvalds 已提交
2169 2170 2171 2172 2173 2174 2175 2176 2177

		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) {
2178 2179 2180 2181
		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
2182 2183 2184 2185
		data_was_unread += len;
		__kfree_skb(skb);
	}

2186
	sk_mem_reclaim(sk);
L
Linus Torvalds 已提交
2187

2188 2189 2190 2191
	/* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
	if (sk->sk_state == TCP_CLOSE)
		goto adjudge_to_death;

2192 2193 2194 2195 2196 2197
	/* 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
2198
	 */
P
Pavel Emelyanov 已提交
2199 2200 2201
	if (unlikely(tcp_sk(sk)->repair)) {
		sk->sk_prot->disconnect(sk, 0);
	} else if (data_was_unread) {
L
Linus Torvalds 已提交
2202
		/* Unread data was tossed, zap the connection. */
2203
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
L
Linus Torvalds 已提交
2204
		tcp_set_state(sk, TCP_CLOSE);
2205
		tcp_send_active_reset(sk, sk->sk_allocation);
L
Linus Torvalds 已提交
2206 2207 2208
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
2209
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
L
Linus Torvalds 已提交
2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234
	} 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
2235 2236 2237 2238
		 * 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
2239 2240 2241 2242 2243 2244 2245
		 */
		tcp_send_fin(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
H
Herbert Xu 已提交
2246 2247 2248 2249
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

L
Linus Torvalds 已提交
2250 2251 2252 2253 2254
	/* 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
2255
	 *  to finish close. No need to check for user refs.
L
Linus Torvalds 已提交
2256 2257 2258
	 */
	local_bh_disable();
	bh_lock_sock(sk);
2259
	WARN_ON(sock_owned_by_user(sk));
L
Linus Torvalds 已提交
2260

H
Herbert Xu 已提交
2261 2262
	percpu_counter_inc(sk->sk_prot->orphan_count);

H
Herbert Xu 已提交
2263 2264 2265
	/* 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
2266 2267 2268 2269

	/*	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.
2270
	 *	We use a 1 minute timeout (about the same as BSD) then kill
L
Linus Torvalds 已提交
2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285
	 *	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);
2286
			__NET_INC_STATS(sock_net(sk),
2287
					LINUX_MIB_TCPABORTONLINGER);
L
Linus Torvalds 已提交
2288
		} else {
2289
			const int tmo = tcp_fin_time(sk);
L
Linus Torvalds 已提交
2290 2291

			if (tmo > TCP_TIMEWAIT_LEN) {
2292 2293
				inet_csk_reset_keepalive_timer(sk,
						tmo - TCP_TIMEWAIT_LEN);
L
Linus Torvalds 已提交
2294 2295 2296 2297 2298 2299 2300
			} else {
				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
				goto out;
			}
		}
	}
	if (sk->sk_state != TCP_CLOSE) {
2301
		sk_mem_reclaim(sk);
A
Arun Sharma 已提交
2302
		if (tcp_check_oom(sk, 0)) {
L
Linus Torvalds 已提交
2303 2304
			tcp_set_state(sk, TCP_CLOSE);
			tcp_send_active_reset(sk, GFP_ATOMIC);
2305
			__NET_INC_STATS(sock_net(sk),
2306
					LINUX_MIB_TCPABORTONMEMORY);
L
Linus Torvalds 已提交
2307 2308 2309
		}
	}

2310 2311 2312 2313 2314 2315
	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.
		 */
2316
		if (req)
2317
			reqsk_fastopen_remove(sk, req, false);
2318
		inet_csk_destroy_sock(sk);
2319
	}
L
Linus Torvalds 已提交
2320 2321 2322 2323 2324 2325 2326
	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}
E
Eric Dumazet 已提交
2327
EXPORT_SYMBOL(tcp_close);
L
Linus Torvalds 已提交
2328 2329 2330

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

E
Eric Dumazet 已提交
2331
static inline bool tcp_need_reset(int state)
L
Linus Torvalds 已提交
2332 2333 2334 2335 2336 2337
{
	return (1 << state) &
	       (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
		TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
}

2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353
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);
	}
}

2354 2355 2356 2357 2358 2359 2360 2361 2362
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);
	}
2363
	tcp_rtx_queue_purge(sk);
2364 2365 2366 2367 2368
	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
2369 2370 2371
int tcp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
2372
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2373 2374 2375 2376 2377 2378 2379 2380 2381
	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) {
2382
		inet_csk_listen_stop(sk);
P
Pavel Emelyanov 已提交
2383 2384
	} else if (unlikely(tp->repair)) {
		sk->sk_err = ECONNABORTED;
L
Linus Torvalds 已提交
2385 2386 2387
	} 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
2388
		/* The last check adjusts for discrepancy of Linux wrt. RFC
L
Linus Torvalds 已提交
2389 2390 2391 2392 2393 2394 2395 2396 2397
		 * 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);
2398
	tcp_write_queue_purge(sk);
2399
	tcp_fastopen_active_disable_ofo_check(sk);
2400
	skb_rbtree_purge(&tp->out_of_order_queue);
L
Linus Torvalds 已提交
2401

E
Eric Dumazet 已提交
2402
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
2403 2404 2405 2406 2407 2408

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

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);
2409
	tp->srtt_us = 0;
2410 2411
	tp->write_seq += tp->max_window + 2;
	if (tp->write_seq == 0)
L
Linus Torvalds 已提交
2412
		tp->write_seq = 1;
2413
	icsk->icsk_backoff = 0;
L
Linus Torvalds 已提交
2414
	tp->snd_cwnd = 2;
2415
	icsk->icsk_probes_out = 0;
L
Linus Torvalds 已提交
2416
	tp->packets_out = 0;
I
Ilpo Järvinen 已提交
2417
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
L
Linus Torvalds 已提交
2418
	tp->snd_cwnd_cnt = 0;
2419
	tp->window_clamp = 0;
2420
	tcp_set_ca_state(sk, TCP_CA_Open);
L
Linus Torvalds 已提交
2421
	tcp_clear_retrans(tp);
2422
	inet_csk_delack_init(sk);
2423 2424 2425 2426
	/* 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;
2427
	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
L
Linus Torvalds 已提交
2428
	__sk_dst_reset(sk);
2429 2430
	dst_release(sk->sk_rx_dst);
	sk->sk_rx_dst = NULL;
2431
	tcp_saved_syn_free(tp);
L
Linus Torvalds 已提交
2432

2433 2434 2435 2436
	/* Clean up fastopen related fields */
	tcp_free_fastopen_req(tp);
	inet->defer_connect = 0;

E
Eric Dumazet 已提交
2437
	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
L
Linus Torvalds 已提交
2438 2439 2440 2441

	sk->sk_error_report(sk);
	return err;
}
E
Eric Dumazet 已提交
2442
EXPORT_SYMBOL(tcp_disconnect);
L
Linus Torvalds 已提交
2443

E
Eric Dumazet 已提交
2444
static inline bool tcp_can_repair_sock(const struct sock *sk)
P
Pavel Emelyanov 已提交
2445
{
2446
	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2447
		(sk->sk_state != TCP_LISTEN);
P
Pavel Emelyanov 已提交
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 2474 2475 2476 2477 2478 2479 2480 2481
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;
}

2482
static int tcp_repair_options_est(struct sock *sk,
2483
		struct tcp_repair_opt __user *optbuf, unsigned int len)
2484
{
2485
	struct tcp_sock *tp = tcp_sk(sk);
2486
	struct tcp_repair_opt opt;
2487

2488 2489
	while (len >= sizeof(opt)) {
		if (copy_from_user(&opt, optbuf, sizeof(opt)))
2490 2491 2492
			return -EFAULT;

		optbuf++;
2493
		len -= sizeof(opt);
2494

2495 2496 2497
		switch (opt.opt_code) {
		case TCPOPT_MSS:
			tp->rx_opt.mss_clamp = opt.opt_val;
2498
			tcp_mtup_init(sk);
2499
			break;
2500
		case TCPOPT_WINDOW:
2501 2502 2503 2504
			{
				u16 snd_wscale = opt.opt_val & 0xFFFF;
				u16 rcv_wscale = opt.opt_val >> 16;

2505
				if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2506
					return -EFBIG;
2507

2508 2509 2510 2511
				tp->rx_opt.snd_wscale = snd_wscale;
				tp->rx_opt.rcv_wscale = rcv_wscale;
				tp->rx_opt.wscale_ok = 1;
			}
2512 2513
			break;
		case TCPOPT_SACK_PERM:
2514 2515 2516
			if (opt.opt_val != 0)
				return -EINVAL;

2517
			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
E
Eric Dumazet 已提交
2518
			if (sock_net(sk)->ipv4.sysctl_tcp_fack)
2519 2520 2521
				tcp_enable_fack(tp);
			break;
		case TCPOPT_TIMESTAMP:
2522 2523 2524
			if (opt.opt_val != 0)
				return -EINVAL;

2525 2526 2527 2528 2529 2530 2531 2532
			tp->rx_opt.tstamp_ok = 1;
			break;
		}
	}

	return 0;
}

L
Linus Torvalds 已提交
2533 2534 2535
/*
 *	Socket option code for TCP.
 */
2536
static int do_tcp_setsockopt(struct sock *sk, int level,
2537
		int optname, char __user *optval, unsigned int optlen)
L
Linus Torvalds 已提交
2538 2539
{
	struct tcp_sock *tp = tcp_sk(sk);
2540
	struct inet_connection_sock *icsk = inet_csk(sk);
2541
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2542 2543 2544
	int val;
	int err = 0;

2545 2546 2547
	/* These are data/string values, all the others are ints */
	switch (optname) {
	case TCP_CONGESTION: {
2548 2549 2550 2551 2552 2553
		char name[TCP_CA_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
2554
					min_t(long, TCP_CA_NAME_MAX-1, optlen));
2555 2556 2557 2558 2559
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
2560
		err = tcp_set_congestion_control(sk, name, true, true);
2561 2562 2563
		release_sock(sk);
		return err;
	}
D
Dave Watson 已提交
2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581
	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;
	}
2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592
	case TCP_FASTOPEN_KEY: {
		__u8 key[TCP_FASTOPEN_KEY_LENGTH];

		if (optlen != sizeof(key))
			return -EINVAL;

		if (copy_from_user(key, optval, optlen))
			return -EFAULT;

		return tcp_fastopen_reset_cipher(net, sk, key, sizeof(key));
	}
2593 2594 2595
	default:
		/* fallthru */
		break;
2596
	}
2597

L
Linus Torvalds 已提交
2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609
	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
2610 2611
		 * know which interface is going to be used
		 */
2612
		if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
L
Linus Torvalds 已提交
2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629
			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;
2630
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2631 2632 2633 2634 2635
		} else {
			tp->nonagle &= ~TCP_NAGLE_OFF;
		}
		break;

A
Andreas Petlund 已提交
2636 2637 2638 2639 2640 2641 2642
	case TCP_THIN_LINEAR_TIMEOUTS:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->thin_lto = val;
		break;

A
Andreas Petlund 已提交
2643 2644 2645 2646 2647
	case TCP_THIN_DUPACK:
		if (val < 0 || val > 1)
			err = -EINVAL;
		break;

P
Pavel Emelyanov 已提交
2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683
	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;

2684 2685 2686 2687
	case TCP_REPAIR_OPTIONS:
		if (!tp->repair)
			err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
2688
			err = tcp_repair_options_est(sk,
2689 2690
					(struct tcp_repair_opt __user *)optval,
					optlen);
2691 2692 2693 2694
		else
			err = -EPERM;
		break;

L
Linus Torvalds 已提交
2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712
	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;
2713
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724
		}
		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))) {
2725
				u32 elapsed = keepalive_time_elapsed(tp);
L
Linus Torvalds 已提交
2726 2727 2728 2729
				if (tp->keepalive_time > elapsed)
					elapsed = tp->keepalive_time - elapsed;
				else
					elapsed = 0;
2730
				inet_csk_reset_keepalive_timer(sk, elapsed);
L
Linus Torvalds 已提交
2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749
			}
		}
		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
2750
			icsk->icsk_syn_retries = val;
L
Linus Torvalds 已提交
2751 2752
		break;

2753 2754 2755 2756 2757 2758 2759
	case TCP_SAVE_SYN:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->save_syn = val;
		break;

L
Linus Torvalds 已提交
2760 2761 2762
	case TCP_LINGER2:
		if (val < 0)
			tp->linger2 = -1;
2763
		else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
L
Linus Torvalds 已提交
2764 2765 2766 2767 2768 2769
			tp->linger2 = 0;
		else
			tp->linger2 = val * HZ;
		break;

	case TCP_DEFER_ACCEPT:
2770 2771 2772 2773
		/* 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
2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789
		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) {
2790
			icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2791
		} else {
2792
			icsk->icsk_ack.pingpong = 0;
L
Linus Torvalds 已提交
2793 2794
			if ((1 << sk->sk_state) &
			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2795 2796
			    inet_csk_ack_scheduled(sk)) {
				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2797
				tcp_cleanup_rbuf(sk, 1);
L
Linus Torvalds 已提交
2798
				if (!(val & 1))
2799
					icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2800 2801 2802 2803
			}
		}
		break;

2804 2805
#ifdef CONFIG_TCP_MD5SIG
	case TCP_MD5SIG:
2806
	case TCP_MD5SIG_EXT:
2807
		/* Read the IP->Key mappings from userspace */
2808
		err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
2809 2810
		break;
#endif
2811
	case TCP_USER_TIMEOUT:
2812
		/* Cap the max time in ms TCP will retry or probe the window
2813 2814
		 * before giving up and aborting (ETIMEDOUT) a connection.
		 */
2815 2816 2817 2818
		if (val < 0)
			err = -EINVAL;
		else
			icsk->icsk_user_timeout = msecs_to_jiffies(val);
2819
		break;
2820 2821 2822

	case TCP_FASTOPEN:
		if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2823
		    TCPF_LISTEN))) {
2824
			tcp_fastopen_init_key_once(net);
2825

2826
			fastopen_queue_tune(sk, val);
2827
		} else {
2828
			err = -EINVAL;
2829
		}
2830
		break;
W
Wei Wang 已提交
2831 2832 2833
	case TCP_FASTOPEN_CONNECT:
		if (val > 1 || val < 0) {
			err = -EINVAL;
2834
		} else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
W
Wei Wang 已提交
2835 2836 2837 2838 2839 2840 2841 2842
			if (sk->sk_state == TCP_CLOSE)
				tp->fastopen_connect = val;
			else
				err = -EINVAL;
		} else {
			err = -EOPNOTSUPP;
		}
		break;
2843 2844 2845 2846 2847 2848 2849 2850
	case TCP_FASTOPEN_NO_COOKIE:
		if (val > 1 || val < 0)
			err = -EINVAL;
		else if (!((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			err = -EINVAL;
		else
			tp->fastopen_no_cookie = val;
		break;
2851 2852 2853 2854
	case TCP_TIMESTAMP:
		if (!tp->repair)
			err = -EPERM;
		else
2855
			tp->tsoffset = val - tcp_time_stamp_raw();
2856
		break;
2857 2858 2859
	case TCP_REPAIR_WINDOW:
		err = tcp_repair_set_window(tp, optval, optlen);
		break;
2860 2861 2862 2863
	case TCP_NOTSENT_LOWAT:
		tp->notsent_lowat = val;
		sk->sk_write_space(sk);
		break;
L
Linus Torvalds 已提交
2864 2865 2866
	default:
		err = -ENOPROTOOPT;
		break;
2867 2868
	}

L
Linus Torvalds 已提交
2869 2870 2871 2872
	release_sock(sk);
	return err;
}

2873
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2874
		   unsigned int optlen)
2875
{
2876
	const struct inet_connection_sock *icsk = inet_csk(sk);
2877 2878 2879 2880 2881 2882

	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
2883
EXPORT_SYMBOL(tcp_setsockopt);
2884 2885

#ifdef CONFIG_COMPAT
2886
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2887
			  char __user *optval, unsigned int optlen)
2888
{
2889 2890 2891
	if (level != SOL_TCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
2892 2893
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
2894
EXPORT_SYMBOL(compat_tcp_setsockopt);
2895 2896
#endif

2897 2898 2899 2900 2901 2902 2903 2904 2905
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)
2906
			stats[i] += tcp_jiffies32 - tp->chrono_start;
2907 2908 2909 2910 2911 2912 2913 2914 2915
		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
2916
/* Return information about state of tcp endpoint in API format. */
2917
void tcp_get_info(struct sock *sk, struct tcp_info *info)
L
Linus Torvalds 已提交
2918
{
2919
	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
2920
	const struct inet_connection_sock *icsk = inet_csk(sk);
2921
	u32 now;
2922
	u64 rate64;
2923
	bool slow;
2924
	u32 rate;
L
Linus Torvalds 已提交
2925 2926

	memset(info, 0, sizeof(*info));
2927 2928
	if (sk->sk_type != SOCK_STREAM)
		return;
L
Linus Torvalds 已提交
2929

2930 2931
	info->tcpi_state = sk_state_load(sk);

2932 2933 2934
	/* Report meaningful fields for all TCP states, including listeners */
	rate = READ_ONCE(sk->sk_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2935
	info->tcpi_pacing_rate = rate64;
2936 2937 2938

	rate = READ_ONCE(sk->sk_max_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2939
	info->tcpi_max_pacing_rate = rate64;
2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952

	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;
	}
2953 2954 2955

	slow = lock_sock_fast(sk);

2956
	info->tcpi_ca_state = icsk->icsk_ca_state;
2957
	info->tcpi_retransmits = icsk->icsk_retransmits;
2958
	info->tcpi_probes = icsk->icsk_probes_out;
2959
	info->tcpi_backoff = icsk->icsk_backoff;
L
Linus Torvalds 已提交
2960 2961 2962

	if (tp->rx_opt.tstamp_ok)
		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2963
	if (tcp_is_sack(tp))
L
Linus Torvalds 已提交
2964 2965 2966 2967 2968
		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;
2969
	}
L
Linus Torvalds 已提交
2970

E
Eric Dumazet 已提交
2971
	if (tp->ecn_flags & TCP_ECN_OK)
L
Linus Torvalds 已提交
2972
		info->tcpi_options |= TCPI_OPT_ECN;
E
Eric Dumazet 已提交
2973 2974
	if (tp->ecn_flags & TCP_ECN_SEEN)
		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Y
Yuchung Cheng 已提交
2975 2976
	if (tp->syn_data_acked)
		info->tcpi_options |= TCPI_OPT_SYN_DATA;
L
Linus Torvalds 已提交
2977

2978 2979
	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2980
	info->tcpi_snd_mss = tp->mss_cache;
2981
	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
L
Linus Torvalds 已提交
2982

2983 2984 2985
	info->tcpi_unacked = tp->packets_out;
	info->tcpi_sacked = tp->sacked_out;

L
Linus Torvalds 已提交
2986 2987 2988 2989
	info->tcpi_lost = tp->lost_out;
	info->tcpi_retrans = tp->retrans_out;
	info->tcpi_fackets = tp->fackets_out;

2990
	now = tcp_jiffies32;
L
Linus Torvalds 已提交
2991
	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2992
	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
L
Linus Torvalds 已提交
2993 2994
	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);

2995
	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
L
Linus Torvalds 已提交
2996
	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2997 2998
	info->tcpi_rtt = tp->srtt_us >> 3;
	info->tcpi_rttvar = tp->mdev_us >> 2;
L
Linus Torvalds 已提交
2999 3000 3001
	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
	info->tcpi_advmss = tp->advmss;

3002
	info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
L
Linus Torvalds 已提交
3003 3004 3005
	info->tcpi_rcv_space = tp->rcvq_space.space;

	info->tcpi_total_retrans = tp->total_retrans;
3006

3007 3008
	info->tcpi_bytes_acked = tp->bytes_acked;
	info->tcpi_bytes_received = tp->bytes_received;
3009
	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
3010
	tcp_get_info_chrono_stats(tp, info);
3011

3012 3013
	info->tcpi_segs_out = tp->segs_out;
	info->tcpi_segs_in = tp->segs_in;
3014 3015

	info->tcpi_min_rtt = tcp_min_rtt(tp);
3016 3017
	info->tcpi_data_segs_in = tp->data_segs_in;
	info->tcpi_data_segs_out = tp->data_segs_out;
Y
Yuchung Cheng 已提交
3018 3019

	info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
3020 3021
	rate64 = tcp_compute_delivery_rate(tp);
	if (rate64)
3022
		info->tcpi_delivery_rate = rate64;
3023
	unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
3024 3025 3026
}
EXPORT_SYMBOL_GPL(tcp_get_info);

3027 3028 3029 3030 3031
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;
3032 3033
	u64 rate64;
	u32 rate;
3034

3035 3036 3037
	stats = alloc_skb(7 * nla_total_size_64bit(sizeof(u64)) +
			  3 * nla_total_size(sizeof(u32)) +
			  2 * nla_total_size(sizeof(u8)), GFP_ATOMIC);
3038 3039 3040 3041 3042 3043 3044 3045 3046 3047
	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);
3048 3049 3050 3051
	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);
3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065

	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);
3066 3067 3068
	return stats;
}

3069 3070
static int do_tcp_getsockopt(struct sock *sk, int level,
		int optname, char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
3071
{
3072
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
3073
	struct tcp_sock *tp = tcp_sk(sk);
3074
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086
	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:
3087
		val = tp->mss_cache;
L
Linus Torvalds 已提交
3088 3089
		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			val = tp->rx_opt.user_mss;
3090 3091
		if (tp->repair)
			val = tp->rx_opt.mss_clamp;
L
Linus Torvalds 已提交
3092 3093 3094 3095 3096 3097 3098 3099
		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
3100
		val = keepalive_time_when(tp) / HZ;
L
Linus Torvalds 已提交
3101 3102
		break;
	case TCP_KEEPINTVL:
E
Eric Dumazet 已提交
3103
		val = keepalive_intvl_when(tp) / HZ;
L
Linus Torvalds 已提交
3104 3105
		break;
	case TCP_KEEPCNT:
E
Eric Dumazet 已提交
3106
		val = keepalive_probes(tp);
L
Linus Torvalds 已提交
3107 3108
		break;
	case TCP_SYNCNT:
3109
		val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
L
Linus Torvalds 已提交
3110 3111 3112 3113
		break;
	case TCP_LINGER2:
		val = tp->linger2;
		if (val >= 0)
3114
			val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
L
Linus Torvalds 已提交
3115 3116
		break;
	case TCP_DEFER_ACCEPT:
3117 3118
		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
3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137
		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;
	}
3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157
	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
3158
	case TCP_QUICKACK:
3159
		val = !icsk->icsk_ack.pingpong;
L
Linus Torvalds 已提交
3160
		break;
3161 3162 3163 3164 3165 3166 3167

	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;
3168
		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
3169 3170
			return -EFAULT;
		return 0;
3171

D
Dave Watson 已提交
3172 3173 3174 3175
	case TCP_ULP:
		if (get_user(len, optlen))
			return -EFAULT;
		len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
3176 3177 3178 3179 3180
		if (!icsk->icsk_ulp_ops) {
			if (put_user(0, optlen))
				return -EFAULT;
			return 0;
		}
D
Dave Watson 已提交
3181 3182 3183 3184 3185 3186
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len))
			return -EFAULT;
		return 0;

3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208
	case TCP_FASTOPEN_KEY: {
		__u8 key[TCP_FASTOPEN_KEY_LENGTH];
		struct tcp_fastopen_context *ctx;

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

		rcu_read_lock();
		ctx = rcu_dereference(icsk->icsk_accept_queue.fastopenq.ctx);
		if (ctx)
			memcpy(key, ctx->key, sizeof(key));
		else
			len = 0;
		rcu_read_unlock();

		len = min_t(unsigned int, len, sizeof(key));
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, key, len))
			return -EFAULT;
		return 0;
	}
3209 3210 3211
	case TCP_THIN_LINEAR_TIMEOUTS:
		val = tp->thin_lto;
		break;
Y
Yuchung Cheng 已提交
3212

3213
	case TCP_THIN_DUPACK:
Y
Yuchung Cheng 已提交
3214
		val = 0;
3215
		break;
3216

P
Pavel Emelyanov 已提交
3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227
	case TCP_REPAIR:
		val = tp->repair;
		break;

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

3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249
	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
3250 3251 3252 3253 3254 3255 3256 3257 3258
	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;

3259 3260 3261
	case TCP_USER_TIMEOUT:
		val = jiffies_to_msecs(icsk->icsk_user_timeout);
		break;
3262 3263

	case TCP_FASTOPEN:
3264
		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3265 3266
		break;

W
Wei Wang 已提交
3267 3268 3269 3270
	case TCP_FASTOPEN_CONNECT:
		val = tp->fastopen_connect;
		break;

3271 3272 3273 3274
	case TCP_FASTOPEN_NO_COOKIE:
		val = tp->fastopen_no_cookie;
		break;

3275
	case TCP_TIMESTAMP:
3276
		val = tcp_time_stamp_raw() + tp->tsoffset;
3277
		break;
3278 3279 3280
	case TCP_NOTSENT_LOWAT:
		val = tp->notsent_lowat;
		break;
3281 3282 3283 3284 3285 3286 3287 3288 3289
	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) {
3290 3291 3292 3293 3294 3295 3296 3297 3298
			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];
3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316
			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
3317 3318
	default:
		return -ENOPROTOOPT;
3319
	}
L
Linus Torvalds 已提交
3320 3321 3322 3323 3324 3325 3326 3327

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

3328 3329 3330 3331 3332 3333 3334 3335 3336 3337
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
3338
EXPORT_SYMBOL(tcp_getsockopt);
3339 3340

#ifdef CONFIG_COMPAT
3341 3342
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
			  char __user *optval, int __user *optlen)
3343
{
3344 3345 3346
	if (level != SOL_TCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
3347 3348
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
3349
EXPORT_SYMBOL(compat_tcp_getsockopt);
3350
#endif
L
Linus Torvalds 已提交
3351

3352
#ifdef CONFIG_TCP_MD5SIG
E
Eric Dumazet 已提交
3353
static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3354
static DEFINE_MUTEX(tcp_md5sig_mutex);
E
Eric Dumazet 已提交
3355
static bool tcp_md5sig_pool_populated = false;
3356

3357
static void __tcp_alloc_md5sig_pool(void)
3358
{
H
Herbert Xu 已提交
3359
	struct crypto_ahash *hash;
3360 3361
	int cpu;

H
Herbert Xu 已提交
3362
	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3363
	if (IS_ERR(hash))
H
Herbert Xu 已提交
3364 3365
		return;

3366
	for_each_possible_cpu(cpu) {
3367
		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
H
Herbert Xu 已提交
3368
		struct ahash_request *req;
3369

3370 3371 3372 3373 3374 3375 3376 3377 3378
		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
3379 3380 3381 3382 3383 3384 3385 3386 3387 3388
		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;
3389
	}
E
Eric Dumazet 已提交
3390 3391
	/* before setting tcp_md5sig_pool_populated, we must commit all writes
	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3392 3393
	 */
	smp_wmb();
E
Eric Dumazet 已提交
3394
	tcp_md5sig_pool_populated = true;
3395 3396
}

3397
bool tcp_alloc_md5sig_pool(void)
3398
{
E
Eric Dumazet 已提交
3399
	if (unlikely(!tcp_md5sig_pool_populated)) {
3400 3401
		mutex_lock(&tcp_md5sig_mutex);

E
Eric Dumazet 已提交
3402
		if (!tcp_md5sig_pool_populated)
3403 3404 3405
			__tcp_alloc_md5sig_pool();

		mutex_unlock(&tcp_md5sig_mutex);
3406
	}
E
Eric Dumazet 已提交
3407
	return tcp_md5sig_pool_populated;
3408 3409 3410
}
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);

E
Eric Dumazet 已提交
3411 3412 3413 3414 3415 3416 3417 3418 3419

/**
 *	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)
3420
{
E
Eric Dumazet 已提交
3421
	local_bh_disable();
3422

E
Eric Dumazet 已提交
3423 3424 3425 3426 3427
	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
3428 3429 3430 3431
	local_bh_enable();
	return NULL;
}
EXPORT_SYMBOL(tcp_get_md5sig_pool);
3432

3433
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3434
			  const struct sk_buff *skb, unsigned int header_len)
3435 3436 3437
{
	struct scatterlist sg;
	const struct tcphdr *tp = tcp_hdr(skb);
H
Herbert Xu 已提交
3438
	struct ahash_request *req = hp->md5_req;
3439 3440 3441
	unsigned int i;
	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
					   skb_headlen(skb) - header_len : 0;
3442
	const struct skb_shared_info *shi = skb_shinfo(skb);
3443
	struct sk_buff *frag_iter;
3444 3445 3446 3447

	sg_init_table(&sg, 1);

	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
H
Herbert Xu 已提交
3448 3449
	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
	if (crypto_ahash_update(req))
3450 3451 3452 3453
		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
3454 3455 3456 3457 3458
		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
3459 3460
		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
		if (crypto_ahash_update(req))
3461 3462 3463
			return 1;
	}

3464 3465 3466 3467
	skb_walk_frags(skb, frag_iter)
		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
			return 1;

3468 3469 3470 3471
	return 0;
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

3472
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3473 3474 3475 3476
{
	struct scatterlist sg;

	sg_init_one(&sg, key->key, key->keylen);
H
Herbert Xu 已提交
3477 3478
	ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
	return crypto_ahash_update(hp->md5_req);
3479 3480 3481
}
EXPORT_SYMBOL(tcp_md5_hash_key);

3482 3483
#endif

A
Andi Kleen 已提交
3484 3485
void tcp_done(struct sock *sk)
{
3486 3487
	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;

3488
	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3489
		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
A
Andi Kleen 已提交
3490 3491 3492

	tcp_set_state(sk, TCP_CLOSE);
	tcp_clear_xmit_timers(sk);
3493
	if (req)
3494
		reqsk_fastopen_remove(sk, req, false);
A
Andi Kleen 已提交
3495 3496 3497 3498 3499 3500 3501 3502 3503 3504

	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);

3505 3506 3507
int tcp_abort(struct sock *sk, int err)
{
	if (!sk_fullsock(sk)) {
3508 3509 3510 3511 3512 3513 3514 3515 3516
		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;
		}
3517 3518 3519 3520 3521 3522
		return -EOPNOTSUPP;
	}

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

3523 3524 3525 3526 3527
	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);
		inet_csk_listen_stop(sk);
	}

3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548
	/* 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);

3549
extern struct tcp_congestion_ops tcp_reno;
L
Linus Torvalds 已提交
3550 3551 3552 3553

static __initdata unsigned long thash_entries;
static int __init set_thash_entries(char *str)
{
3554 3555
	ssize_t ret;

L
Linus Torvalds 已提交
3556 3557
	if (!str)
		return 0;
3558 3559 3560 3561 3562

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

L
Linus Torvalds 已提交
3563 3564 3565 3566
	return 1;
}
__setup("thash_entries=", set_thash_entries);

F
Fabian Frederick 已提交
3567
static void __init tcp_init_mem(void)
3568
{
E
Eric Dumazet 已提交
3569 3570
	unsigned long limit = nr_free_buffer_pages() / 16;

3571
	limit = max(limit, 128UL);
E
Eric Dumazet 已提交
3572 3573 3574
	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 % */
3575 3576
}

L
Linus Torvalds 已提交
3577 3578
void __init tcp_init(void)
{
3579
	int max_rshare, max_wshare, cnt;
3580
	unsigned long limit;
3581
	unsigned int i;
L
Linus Torvalds 已提交
3582

3583 3584
	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
L
Linus Torvalds 已提交
3585

3586 3587
	percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
	percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3588
	inet_hashinfo_init(&tcp_hashinfo);
3589 3590 3591
	tcp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("tcp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
3592
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
3593 3594 3595 3596 3597 3598

	/* Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
3599
	tcp_hashinfo.ehash =
L
Linus Torvalds 已提交
3600
		alloc_large_system_hash("TCP established",
3601
					sizeof(struct inet_ehash_bucket),
L
Linus Torvalds 已提交
3602
					thash_entries,
E
Eric Dumazet 已提交
3603
					17, /* one slot per 128 KB of memory */
3604
					0,
L
Linus Torvalds 已提交
3605
					NULL,
3606
					&tcp_hashinfo.ehash_mask,
3607
					0,
3608
					thash_entries ? 0 : 512 * 1024);
E
Eric Dumazet 已提交
3609
	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3610
		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
E
Eric Dumazet 已提交
3611

3612 3613
	if (inet_ehash_locks_alloc(&tcp_hashinfo))
		panic("TCP: failed to alloc ehash_locks");
3614
	tcp_hashinfo.bhash =
L
Linus Torvalds 已提交
3615
		alloc_large_system_hash("TCP bind",
3616
					sizeof(struct inet_bind_hashbucket),
3617
					tcp_hashinfo.ehash_mask + 1,
E
Eric Dumazet 已提交
3618
					17, /* one slot per 128 KB of memory */
3619
					0,
3620
					&tcp_hashinfo.bhash_size,
L
Linus Torvalds 已提交
3621
					NULL,
3622
					0,
L
Linus Torvalds 已提交
3623
					64 * 1024);
3624
	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3625 3626 3627
	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
3628 3629
	}

E
Eric Dumazet 已提交
3630 3631 3632

	cnt = tcp_hashinfo.ehash_mask + 1;
	sysctl_tcp_max_orphans = cnt / 2;
L
Linus Torvalds 已提交
3633

3634
	tcp_init_mem();
3635
	/* Set per-socket limits to no more than 1/128 the pressure threshold */
E
Eric Dumazet 已提交
3636
	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3637 3638
	max_wshare = min(4UL*1024*1024, limit);
	max_rshare = min(6UL*1024*1024, limit);
3639

3640
	sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3641
	sysctl_tcp_wmem[1] = 16*1024;
3642
	sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
3643

3644
	sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3645
	sysctl_tcp_rmem[1] = 87380;
3646
	sysctl_tcp_rmem[2] = max(87380, max_rshare);
L
Linus Torvalds 已提交
3647

3648
	pr_info("Hash tables configured (established %u bind %u)\n",
J
Joe Perches 已提交
3649
		tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3650

3651
	tcp_v4_init();
3652
	tcp_metrics_init();
3653
	BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
E
Eric Dumazet 已提交
3654
	tcp_tasklet_init();
L
Linus Torvalds 已提交
3655
}