tcp.c 102.7 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>
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#include <linux/memblock.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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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;
EXPORT_SYMBOL(sysctl_tcp_mem);
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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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	tp->rack.reo_wnd_steps = 1;
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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;

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	sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1];
	sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1];
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	sk_sockets_allocated_inc(sk);
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	sk->sk_route_forced_caps = NETIF_F_GSO;
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}
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);
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	tcp_call_bpf(sk, bpf_op, 0, NULL);
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	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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static inline bool tcp_stream_is_readable(const struct tcp_sock *tp,
					  int target, struct sock *sk)
{
	return (tp->rcv_nxt - tp->copied_seq >= target) ||
		(sk->sk_prot->stream_memory_read ?
		sk->sk_prot->stream_memory_read(sk) : false);
}

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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.
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 */
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__poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
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{
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	__poll_t mask;
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	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_poll_wait(file, sock, wait);
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	state = inet_sk_state_load(sk);
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	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
	 * by poll logic and correct handling of state changes
	 * made by other threads is impossible in any case.
	 */

	mask = 0;

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	/*
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	 * EPOLLHUP is certainly not done right. But poll() doesn't
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	 * have a notion of HUP in just one direction, and for a
	 * socket the read side is more interesting.
	 *
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	 * Some poll() documentation says that EPOLLHUP is incompatible
	 * with the EPOLLOUT/POLLWR flags, so somebody should check this
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	 * 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.
	 *
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	 * Check number 1. EPOLLHUP is _UNMASKABLE_ event (see UNIX98 and
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	 * our fs/select.c). It means that after we received EOF,
	 * poll always returns immediately, making impossible poll() on write()
539
	 * in state CLOSE_WAIT. One solution is evident --- to set EPOLLHUP
L
Linus Torvalds 已提交
540 541
	 * if and only if shutdown has been made in both directions.
	 * Actually, it is interesting to look how Solaris and DUX
542
	 * solve this dilemma. I would prefer, if EPOLLHUP were maskable,
L
Linus Torvalds 已提交
543 544
	 * then we could set it on SND_SHUTDOWN. BTW examples given
	 * in Stevens' books assume exactly this behaviour, it explains
545
	 * why EPOLLHUP is incompatible with EPOLLOUT.	--ANK
L
Linus Torvalds 已提交
546 547 548 549
	 *
	 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
	 * blocking on fresh not-connected or disconnected socket. --ANK
	 */
550
	if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
551
		mask |= EPOLLHUP;
L
Linus Torvalds 已提交
552
	if (sk->sk_shutdown & RCV_SHUTDOWN)
553
		mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
L
Linus Torvalds 已提交
554

555
	/* Connected or passive Fast Open socket? */
556 557
	if (state != TCP_SYN_SENT &&
	    (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
558 559 560 561 562
		int target = sock_rcvlowat(sk, 0, INT_MAX);

		if (tp->urg_seq == tp->copied_seq &&
		    !sock_flag(sk, SOCK_URGINLINE) &&
		    tp->urg_data)
563
			target++;
564

565
		if (tcp_stream_is_readable(tp, target, sk))
566
			mask |= EPOLLIN | EPOLLRDNORM;
L
Linus Torvalds 已提交
567 568

		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
569
			if (sk_stream_is_writeable(sk)) {
570
				mask |= EPOLLOUT | EPOLLWRNORM;
L
Linus Torvalds 已提交
571
			} else {  /* send SIGIO later */
572
				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
573 574 575 576
				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);

				/* Race breaker. If space is freed after
				 * wspace test but before the flags are set,
577 578
				 * IO signal will be lost. Memory barrier
				 * pairs with the input side.
L
Linus Torvalds 已提交
579
				 */
580
				smp_mb__after_atomic();
581
				if (sk_stream_is_writeable(sk))
582
					mask |= EPOLLOUT | EPOLLWRNORM;
L
Linus Torvalds 已提交
583
			}
584
		} else
585
			mask |= EPOLLOUT | EPOLLWRNORM;
L
Linus Torvalds 已提交
586 587

		if (tp->urg_data & TCP_URG_VALID)
588
			mask |= EPOLLPRI;
589
	} else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
W
Wei Wang 已提交
590
		/* Active TCP fastopen socket with defer_connect
591
		 * Return EPOLLOUT so application can call write()
W
Wei Wang 已提交
592 593
		 * in order for kernel to generate SYN+data
		 */
594
		mask |= EPOLLOUT | EPOLLWRNORM;
L
Linus Torvalds 已提交
595
	}
T
Tom Marshall 已提交
596 597
	/* This barrier is coupled with smp_wmb() in tcp_reset() */
	smp_rmb();
598
	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
599
		mask |= EPOLLERR;
T
Tom Marshall 已提交
600

L
Linus Torvalds 已提交
601 602
	return mask;
}
603
EXPORT_SYMBOL(tcp_poll);
L
Linus Torvalds 已提交
604 605 606 607 608

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
609
	bool slow;
L
Linus Torvalds 已提交
610 611 612 613 614 615

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

E
Eric Dumazet 已提交
616
		slow = lock_sock_fast(sk);
617
		answ = tcp_inq(sk);
E
Eric Dumazet 已提交
618
		unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
619 620 621 622 623 624 625 626 627 628 629 630 631
		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;
632 633 634 635 636 637 638 639 640
	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
641 642
	default:
		return -ENOIOCTLCMD;
643
	}
L
Linus Torvalds 已提交
644 645 646

	return put_user(answ, (int __user *)arg);
}
E
Eric Dumazet 已提交
647
EXPORT_SYMBOL(tcp_ioctl);
L
Linus Torvalds 已提交
648 649 650

static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
{
E
Eric Dumazet 已提交
651
	TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
L
Linus Torvalds 已提交
652 653 654
	tp->pushed_seq = tp->write_seq;
}

E
Eric Dumazet 已提交
655
static inline bool forced_push(const struct tcp_sock *tp)
L
Linus Torvalds 已提交
656 657 658 659
{
	return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
}

660
static void skb_entail(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
661
{
662
	struct tcp_sock *tp = tcp_sk(sk);
663 664 665 666
	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
667
	tcb->tcp_flags = TCPHDR_ACK;
668
	tcb->sacked  = 0;
669
	__skb_header_release(skb);
670
	tcp_add_write_queue_tail(sk, skb);
671 672
	sk->sk_wmem_queued += skb->truesize;
	sk_mem_charge(sk, skb->truesize);
673
	if (tp->nonagle & TCP_NAGLE_PUSH)
674
		tp->nonagle &= ~TCP_NAGLE_PUSH;
675 676

	tcp_slow_start_after_idle_check(sk);
L
Linus Torvalds 已提交
677 678
}

679
static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
L
Linus Torvalds 已提交
680
{
I
Ilpo Järvinen 已提交
681
	if (flags & MSG_OOB)
L
Linus Torvalds 已提交
682 683 684
		tp->snd_up = tp->write_seq;
}

E
Eric Dumazet 已提交
685
/* If a not yet filled skb is pushed, do not send it if
686
 * we have data packets in Qdisc or NIC queues :
E
Eric Dumazet 已提交
687 688 689 690
 * 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
691 692 693
 * 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
694 695 696
 */
static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
				int size_goal)
L
Linus Torvalds 已提交
697
{
E
Eric Dumazet 已提交
698
	return skb->len < size_goal &&
699
	       sock_net(sk)->ipv4.sysctl_tcp_autocorking &&
E
Eric Dumazet 已提交
700
	       !tcp_rtx_queue_empty(sk) &&
701
	       refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
E
Eric Dumazet 已提交
702 703 704 705 706 707 708
}

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;
709

E
Eric Dumazet 已提交
710
	skb = tcp_write_queue_tail(sk);
711 712
	if (!skb)
		return;
E
Eric Dumazet 已提交
713 714 715 716 717 718 719 720
	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 */
721
		if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
E
Eric Dumazet 已提交
722
			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
723
			set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
E
Eric Dumazet 已提交
724
		}
725 726 727
		/* It is possible TX completion already happened
		 * before we set TSQ_THROTTLED.
		 */
728
		if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
729
			return;
L
Linus Torvalds 已提交
730
	}
E
Eric Dumazet 已提交
731 732 733 734 735

	if (flags & MSG_MORE)
		nonagle = TCP_NAGLE_CORK;

	__tcp_push_pending_frames(sk, mss_now, nonagle);
L
Linus Torvalds 已提交
736 737
}

738 739
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
740 741
{
	struct tcp_splice_state *tss = rd_desc->arg.data;
742
	int ret;
J
Jens Axboe 已提交
743

744
	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
A
Al Viro 已提交
745
			      min(rd_desc->count, len), tss->flags);
746 747 748
	if (ret > 0)
		rd_desc->count -= ret;
	return ret;
J
Jens Axboe 已提交
749 750 751 752 753 754 755
}

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,
756
		.count	  = tss->len,
J
Jens Axboe 已提交
757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787
	};

	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;

788
	sock_rps_record_flow(sk);
J
Jens Axboe 已提交
789 790 791 792 793 794 795 796 797 798
	/*
	 * We can't seek on a socket input
	 */
	if (unlikely(*ppos))
		return -ESPIPE;

	ret = spliced = 0;

	lock_sock(sk);

799
	timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
J
Jens Axboe 已提交
800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819
	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.
				 */
820
				ret = -ENOTCONN;
J
Jens Axboe 已提交
821 822 823 824 825 826
				break;
			}
			if (!timeo) {
				ret = -EAGAIN;
				break;
			}
827 828 829 830 831 832
			/* 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;
833
			sk_wait_data(sk, &timeo, NULL);
J
Jens Axboe 已提交
834 835 836 837 838 839 840 841 842
			if (signal_pending(current)) {
				ret = sock_intr_errno(timeo);
				break;
			}
			continue;
		}
		tss.len -= ret;
		spliced += ret;

843 844
		if (!timeo)
			break;
J
Jens Axboe 已提交
845 846 847 848
		release_sock(sk);
		lock_sock(sk);

		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
849
		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
J
Jens Axboe 已提交
850 851 852 853 854 855 856 857 858 859 860
		    signal_pending(current))
			break;
	}

	release_sock(sk);

	if (spliced)
		return spliced;

	return ret;
}
E
Eric Dumazet 已提交
861
EXPORT_SYMBOL(tcp_splice_read);
J
Jens Axboe 已提交
862

863 864
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
				    bool force_schedule)
865 866 867
{
	struct sk_buff *skb;

868 869 870
	if (likely(!size)) {
		skb = sk->sk_tx_skb_cache;
		if (skb && !skb_cloned(skb)) {
871
			skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
E
Eric Dumazet 已提交
872 873 874
			sk->sk_tx_skb_cache = NULL;
			pskb_trim(skb, 0);
			INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
875 876
			skb_shinfo(skb)->tx_flags = 0;
			memset(TCP_SKB_CB(skb), 0, sizeof(struct tcp_skb_cb));
E
Eric Dumazet 已提交
877 878 879
			return skb;
		}
	}
880 881 882
	/* The TCP header must be at least 32-bit aligned.  */
	size = ALIGN(size, 4);

883 884 885
	if (unlikely(tcp_under_memory_pressure(sk)))
		sk_mem_reclaim_partial(sk);

886
	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
887
	if (likely(skb)) {
888
		bool mem_scheduled;
889

890 891
		if (force_schedule) {
			mem_scheduled = true;
892 893
			sk_forced_mem_schedule(sk, skb->truesize);
		} else {
894
			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
895
		}
896
		if (likely(mem_scheduled)) {
897
			skb_reserve(skb, sk->sk_prot->max_header);
898 899 900 901
			/*
			 * Make sure that we have exactly size bytes
			 * available to the caller, no more, no less.
			 */
E
Eric Dumazet 已提交
902
			skb->reserved_tailroom = skb->end - skb->tail - size;
903
			INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
904 905 906 907
			return skb;
		}
		__kfree_skb(skb);
	} else {
908
		sk->sk_prot->enter_memory_pressure(sk);
909 910 911 912 913
		sk_stream_moderate_sndbuf(sk);
	}
	return NULL;
}

I
Ilpo Järvinen 已提交
914 915 916 917
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
				       int large_allowed)
{
	struct tcp_sock *tp = tcp_sk(sk);
918
	u32 new_size_goal, size_goal;
E
Eric Dumazet 已提交
919

E
Eric Dumazet 已提交
920
	if (!large_allowed)
E
Eric Dumazet 已提交
921 922
		return mss_now;

923 924
	/* 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
925 926 927 928 929 930 931 932 933
	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
934 935
	}

E
Eric Dumazet 已提交
936
	return max(size_goal, mss_now);
I
Ilpo Järvinen 已提交
937 938 939 940 941 942 943 944 945 946 947 948
}

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;
}

949 950
ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
			 size_t size, int flags)
L
Linus Torvalds 已提交
951 952
{
	struct tcp_sock *tp = tcp_sk(sk);
953
	int mss_now, size_goal;
L
Linus Torvalds 已提交
954 955 956 957
	int err;
	ssize_t copied;
	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

958 959 960 961
	if (IS_ENABLED(CONFIG_DEBUG_VM) &&
	    WARN_ONCE(PageSlab(page), "page must not be a Slab one"))
		return -EINVAL;

962 963 964 965 966 967
	/* 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)) {
968 969
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
970
			goto out_err;
971
	}
L
Linus Torvalds 已提交
972

973
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
974

I
Ilpo Järvinen 已提交
975
	mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
976 977 978 979
	copied = 0;

	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
980
		goto out_err;
L
Linus Torvalds 已提交
981

982
	while (size > 0) {
983
		struct sk_buff *skb = tcp_write_queue_tail(sk);
984 985
		int copy, i;
		bool can_coalesce;
L
Linus Torvalds 已提交
986

987
		if (!skb || (copy = size_goal - skb->len) <= 0 ||
988
		    !tcp_skb_can_collapse_to(skb)) {
L
Linus Torvalds 已提交
989 990 991 992
new_segment:
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;

993
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
994
					tcp_rtx_and_write_queues_empty(sk));
L
Linus Torvalds 已提交
995 996 997
			if (!skb)
				goto wait_for_memory;

998
			skb_entail(sk, skb);
999
			copy = size_goal;
L
Linus Torvalds 已提交
1000 1001 1002 1003 1004 1005 1006
		}

		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
1007
		if (!can_coalesce && i >= sysctl_max_skb_frags) {
L
Linus Torvalds 已提交
1008 1009 1010
			tcp_mark_push(tp, skb);
			goto new_segment;
		}
1011
		if (!sk_wmem_schedule(sk, copy))
L
Linus Torvalds 已提交
1012
			goto wait_for_memory;
1013

L
Linus Torvalds 已提交
1014
		if (can_coalesce) {
E
Eric Dumazet 已提交
1015
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
L
Linus Torvalds 已提交
1016 1017 1018 1019
		} else {
			get_page(page);
			skb_fill_page_desc(skb, i, page, offset, copy);
		}
1020 1021 1022

		if (!(flags & MSG_NO_SHARED_FRAGS))
			skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1023

L
Linus Torvalds 已提交
1024 1025 1026 1027
		skb->len += copy;
		skb->data_len += copy;
		skb->truesize += copy;
		sk->sk_wmem_queued += copy;
1028
		sk_mem_charge(sk, copy);
1029
		skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1030 1031
		tp->write_seq += copy;
		TCP_SKB_CB(skb)->end_seq += copy;
1032
		tcp_skb_pcount_set(skb, 0);
L
Linus Torvalds 已提交
1033 1034

		if (!copied)
E
Eric Dumazet 已提交
1035
			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
L
Linus Torvalds 已提交
1036 1037

		copied += copy;
1038
		offset += copy;
1039
		size -= copy;
1040
		if (!size)
L
Linus Torvalds 已提交
1041 1042
			goto out;

1043
		if (skb->len < size_goal || (flags & MSG_OOB))
L
Linus Torvalds 已提交
1044 1045 1046 1047
			continue;

		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
1048
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1049
		} else if (skb == tcp_send_head(sk))
L
Linus Torvalds 已提交
1050 1051 1052 1053 1054 1055
			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
1056 1057
		tcp_push(sk, flags & ~MSG_MORE, mss_now,
			 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1058

1059 1060
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
1061 1062
			goto do_error;

I
Ilpo Järvinen 已提交
1063
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1064 1065 1066
	}

out:
1067
	if (copied) {
E
Eric Dumazet 已提交
1068
		tcp_tx_timestamp(sk, sk->sk_tsflags);
1069 1070 1071
		if (!(flags & MSG_SENDPAGE_NOTLAST))
			tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
	}
L
Linus Torvalds 已提交
1072 1073 1074 1075 1076 1077
	return copied;

do_error:
	if (copied)
		goto out;
out_err:
1078
	/* make sure we wake any epoll edge trigger waiter */
1079 1080
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1081
		sk->sk_write_space(sk);
1082 1083
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1084 1085
	return sk_stream_error(sk, flags, err);
}
1086
EXPORT_SYMBOL_GPL(do_tcp_sendpages);
L
Linus Torvalds 已提交
1087

1088 1089
int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset,
			size_t size, int flags)
L
Linus Torvalds 已提交
1090
{
E
Eric Dumazet 已提交
1091
	if (!(sk->sk_route_caps & NETIF_F_SG))
1092
		return sock_no_sendpage_locked(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1093

1094 1095
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1096 1097
	return do_tcp_sendpages(sk, page, offset, size, flags);
}
1098
EXPORT_SYMBOL_GPL(tcp_sendpage_locked);
1099 1100 1101 1102 1103 1104 1105 1106

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
1107
	release_sock(sk);
1108 1109

	return ret;
L
Linus Torvalds 已提交
1110
}
E
Eric Dumazet 已提交
1111
EXPORT_SYMBOL(tcp_sendpage);
L
Linus Torvalds 已提交
1112

1113 1114
void tcp_free_fastopen_req(struct tcp_sock *tp)
{
1115
	if (tp->fastopen_req) {
1116 1117 1118 1119 1120
		kfree(tp->fastopen_req);
		tp->fastopen_req = NULL;
	}
}

1121
static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
1122 1123
				int *copied, size_t size,
				struct ubuf_info *uarg)
1124 1125
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Wei Wang 已提交
1126
	struct inet_sock *inet = inet_sk(sk);
1127
	struct sockaddr *uaddr = msg->msg_name;
1128 1129
	int err, flags;

1130
	if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
1131 1132
	    (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
	     uaddr->sa_family == AF_UNSPEC))
1133
		return -EOPNOTSUPP;
1134
	if (tp->fastopen_req)
1135 1136 1137 1138
		return -EALREADY; /* Another Fast Open is in progress */

	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
				   sk->sk_allocation);
1139
	if (unlikely(!tp->fastopen_req))
1140 1141
		return -ENOBUFS;
	tp->fastopen_req->data = msg;
1142
	tp->fastopen_req->size = size;
1143
	tp->fastopen_req->uarg = uarg;
1144

W
Wei Wang 已提交
1145 1146 1147 1148 1149 1150 1151 1152 1153
	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;
		}
	}
1154
	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1155
	err = __inet_stream_connect(sk->sk_socket, uaddr,
1156
				    msg->msg_namelen, flags, 1);
1157 1158 1159 1160 1161 1162 1163 1164
	/* 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;
	}
1165 1166 1167
	return err;
}

1168
int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
L
Linus Torvalds 已提交
1169 1170
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Willem de Bruijn 已提交
1171
	struct ubuf_info *uarg = NULL;
L
Linus Torvalds 已提交
1172
	struct sk_buff *skb;
1173
	struct sockcm_cookie sockc;
1174 1175
	int flags, err, copied = 0;
	int mss_now = 0, size_goal, copied_syn = 0;
1176
	bool process_backlog = false;
E
Eric Dumazet 已提交
1177
	bool zc = false;
L
Linus Torvalds 已提交
1178 1179 1180
	long timeo;

	flags = msg->msg_flags;
W
Willem de Bruijn 已提交
1181

1182
	if (flags & MSG_ZEROCOPY && size && sock_flag(sk, SOCK_ZEROCOPY)) {
1183
		skb = tcp_write_queue_tail(sk);
W
Willem de Bruijn 已提交
1184 1185 1186 1187 1188 1189
		uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb));
		if (!uarg) {
			err = -ENOBUFS;
			goto out_err;
		}

E
Eric Dumazet 已提交
1190
		zc = sk->sk_route_caps & NETIF_F_SG;
1191
		if (!zc)
W
Willem de Bruijn 已提交
1192 1193 1194
			uarg->zerocopy = 0;
	}

1195 1196
	if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect) &&
	    !tp->repair) {
1197
		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size, uarg);
1198 1199 1200 1201 1202 1203
		if (err == -EINPROGRESS && copied_syn > 0)
			goto out;
		else if (err)
			goto out_err;
	}

L
Linus Torvalds 已提交
1204 1205
	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

1206 1207
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1208 1209 1210 1211 1212 1213
	/* 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)) {
1214 1215
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
1216
			goto do_error;
1217
	}
L
Linus Torvalds 已提交
1218

P
Pavel Emelyanov 已提交
1219 1220 1221
	if (unlikely(tp->repair)) {
		if (tp->repair_queue == TCP_RECV_QUEUE) {
			copied = tcp_send_rcvq(sk, msg, size);
1222
			goto out_nopush;
P
Pavel Emelyanov 已提交
1223 1224 1225 1226 1227 1228 1229 1230 1231
		}

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

		/* 'common' sending to sendq */
	}

1232
	sockcm_init(&sockc, sk);
1233 1234 1235 1236 1237 1238 1239 1240
	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
1241
	/* This should be in poll */
1242
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
1243 1244 1245 1246

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

1247 1248 1249
restart:
	mss_now = tcp_send_mss(sk, &size_goal, flags);

L
Linus Torvalds 已提交
1250 1251
	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1252
		goto do_error;
L
Linus Torvalds 已提交
1253

A
Al Viro 已提交
1254
	while (msg_data_left(msg)) {
1255
		int copy = 0;
L
Linus Torvalds 已提交
1256

1257
		skb = tcp_write_queue_tail(sk);
1258 1259
		if (skb)
			copy = size_goal - skb->len;
L
Linus Torvalds 已提交
1260

1261
		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1262 1263
			bool first_skb;

L
Linus Torvalds 已提交
1264
new_segment:
1265 1266
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;
L
Linus Torvalds 已提交
1267

1268 1269
			if (process_backlog && sk_flush_backlog(sk)) {
				process_backlog = false;
1270
				goto restart;
1271
			}
1272
			first_skb = tcp_rtx_and_write_queues_empty(sk);
E
Eric Dumazet 已提交
1273
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
1274
						  first_skb);
1275 1276
			if (!skb)
				goto wait_for_memory;
L
Linus Torvalds 已提交
1277

1278
			process_backlog = true;
E
Eric Dumazet 已提交
1279
			skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1280

1281 1282
			skb_entail(sk, skb);
			copy = size_goal;
1283

1284
			/* All packets are restored as if they have
1285
			 * already been sent. skb_mstamp_ns isn't set to
1286 1287 1288 1289 1290
			 * avoid wrong rtt estimation.
			 */
			if (tp->repair)
				TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED;
		}
L
Linus Torvalds 已提交
1291

1292
		/* Try to append data to the end of skb. */
A
Al Viro 已提交
1293 1294
		if (copy > msg_data_left(msg))
			copy = msg_data_left(msg);
1295 1296

		/* Where to copy to? */
1297
		if (skb_availroom(skb) > 0 && !zc) {
1298 1299 1300 1301 1302
			/* 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;
1303
		} else if (!zc) {
1304 1305 1306 1307 1308 1309
			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;
1310

1311 1312
			if (!skb_can_coalesce(skb, i, pfrag->page,
					      pfrag->offset)) {
E
Eric Dumazet 已提交
1313
				if (i >= sysctl_max_skb_frags) {
1314 1315
					tcp_mark_push(tp, skb);
					goto new_segment;
L
Linus Torvalds 已提交
1316
				}
1317
				merge = false;
L
Linus Torvalds 已提交
1318 1319
			}

1320 1321 1322 1323
			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
1324

1325 1326 1327 1328 1329 1330
			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
1331

1332 1333 1334 1335 1336 1337
			/* 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);
1338
				page_ref_inc(pfrag->page);
1339
			}
1340
			pfrag->offset += copy;
W
Willem de Bruijn 已提交
1341 1342
		} else {
			err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
W
Willem de Bruijn 已提交
1343 1344
			if (err == -EMSGSIZE || err == -EEXIST) {
				tcp_mark_push(tp, skb);
W
Willem de Bruijn 已提交
1345
				goto new_segment;
W
Willem de Bruijn 已提交
1346
			}
W
Willem de Bruijn 已提交
1347 1348 1349
			if (err < 0)
				goto do_error;
			copy = err;
1350 1351 1352 1353 1354 1355 1356 1357
		}

		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
1358

1359
		copied += copy;
A
Al Viro 已提交
1360
		if (!msg_data_left(msg)) {
1361 1362
			if (unlikely(flags & MSG_EOR))
				TCP_SKB_CB(skb)->eor = 1;
1363 1364
			goto out;
		}
L
Linus Torvalds 已提交
1365

1366
		if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair))
L
Linus Torvalds 已提交
1367 1368
			continue;

1369 1370 1371 1372 1373 1374 1375
		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
1376
wait_for_sndbuf:
1377
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
L
Linus Torvalds 已提交
1378
wait_for_memory:
1379 1380 1381
		if (copied)
			tcp_push(sk, flags & ~MSG_MORE, mss_now,
				 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1382

1383 1384
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
1385
			goto do_error;
L
Linus Torvalds 已提交
1386

1387
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1388 1389 1390
	}

out:
1391
	if (copied) {
E
Eric Dumazet 已提交
1392
		tcp_tx_timestamp(sk, sockc.tsflags);
E
Eric Dumazet 已提交
1393
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1394
	}
1395
out_nopush:
W
Willem de Bruijn 已提交
1396
	sock_zerocopy_put(uarg);
1397
	return copied + copied_syn;
L
Linus Torvalds 已提交
1398 1399 1400

do_fault:
	if (!skb->len) {
1401 1402 1403 1404
		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.
		 */
1405 1406
		if (tcp_write_queue_empty(sk))
			tcp_chrono_stop(sk, TCP_CHRONO_BUSY);
1407
		sk_wmem_free_skb(sk, skb);
L
Linus Torvalds 已提交
1408 1409 1410
	}

do_error:
1411
	if (copied + copied_syn)
L
Linus Torvalds 已提交
1412 1413
		goto out;
out_err:
1414
	sock_zerocopy_put_abort(uarg, true);
L
Linus Torvalds 已提交
1415
	err = sk_stream_error(sk, flags, err);
1416
	/* make sure we wake any epoll edge trigger waiter */
1417 1418
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1419
		sk->sk_write_space(sk);
1420 1421
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1422 1423
	return err;
}
1424
EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435

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
1436
EXPORT_SYMBOL(tcp_sendmsg);
L
Linus Torvalds 已提交
1437 1438 1439 1440 1441 1442

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

1443
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
L
Linus Torvalds 已提交
1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466
{
	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
1467
				err = memcpy_to_msg(msg, &c, 1);
L
Linus Torvalds 已提交
1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486
			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
1487 1488 1489 1490 1491 1492 1493
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 */

1494 1495 1496 1497 1498 1499 1500
	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
1501
	skb_queue_walk(&sk->sk_write_queue, skb) {
1502
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
P
Pavel Emelyanov 已提交
1503 1504 1505 1506 1507 1508 1509 1510 1511
		if (err)
			break;

		copied += skb->len;
	}

	return err ?: copied;
}

L
Linus Torvalds 已提交
1512 1513 1514 1515 1516 1517
/* 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.
 */
1518
static void tcp_cleanup_rbuf(struct sock *sk, int copied)
L
Linus Torvalds 已提交
1519 1520
{
	struct tcp_sock *tp = tcp_sk(sk);
E
Eric Dumazet 已提交
1521
	bool time_to_ack = false;
L
Linus Torvalds 已提交
1522 1523 1524

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

1525
	WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
J
Joe Perches 已提交
1526
	     "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1527
	     tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
L
Linus Torvalds 已提交
1528

1529 1530
	if (inet_csk_ack_scheduled(sk)) {
		const struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1531 1532
		   /* Delayed ACKs frequently hit locked sockets during bulk
		    * receive. */
1533
		if (icsk->icsk_ack.blocked ||
L
Linus Torvalds 已提交
1534
		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
1535
		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
L
Linus Torvalds 已提交
1536 1537 1538 1539 1540 1541
		    /*
		     * 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.
		     */
1542 1543 1544
		    (copied > 0 &&
		     ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
		      ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
W
Wei Wang 已提交
1545
		       !inet_csk_in_pingpong_mode(sk))) &&
1546
		      !atomic_read(&sk->sk_rmem_alloc)))
E
Eric Dumazet 已提交
1547
			time_to_ack = true;
L
Linus Torvalds 已提交
1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568
	}

	/* 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
1569
				time_to_ack = true;
L
Linus Torvalds 已提交
1570 1571 1572 1573 1574 1575
		}
	}
	if (time_to_ack)
		tcp_send_ack(sk);
}

1576
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
L
Linus Torvalds 已提交
1577 1578 1579 1580
{
	struct sk_buff *skb;
	u32 offset;

1581
	while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
L
Linus Torvalds 已提交
1582
		offset = seq - TCP_SKB_CB(skb)->seq;
1583 1584
		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
1585
			offset--;
1586
		}
1587
		if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
L
Linus Torvalds 已提交
1588 1589 1590
			*off = offset;
			return skb;
		}
1591 1592 1593 1594
		/* 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
1595
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623
	}
	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) {
1624 1625
			int used;
			size_t len;
L
Linus Torvalds 已提交
1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636

			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);
1637
			if (used <= 0) {
1638 1639 1640 1641
				if (!copied)
					copied = used;
				break;
			} else if (used <= len) {
L
Linus Torvalds 已提交
1642 1643 1644 1645
				seq += used;
				copied += used;
				offset += used;
			}
1646
			/* If recv_actor drops the lock (e.g. TCP splice
1647 1648 1649 1650
			 * receive) the skb pointer might be invalid when
			 * getting here: tcp_collapse might have deleted it
			 * while aggregating skbs from the socket queue.
			 */
1651 1652
			skb = tcp_recv_skb(sk, seq - 1, &offset);
			if (!skb)
L
Linus Torvalds 已提交
1653
				break;
1654 1655 1656 1657 1658
			/* 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
1659
		}
1660
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
D
Dan Williams 已提交
1661
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1662 1663 1664
			++seq;
			break;
		}
D
Dan Williams 已提交
1665
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1666 1667
		if (!desc->count)
			break;
1668
		tp->copied_seq = seq;
L
Linus Torvalds 已提交
1669 1670 1671 1672 1673 1674
	}
	tp->copied_seq = seq;

	tcp_rcv_space_adjust(sk);

	/* Clean up data we have read: This will do ACK frames. */
1675 1676
	if (copied > 0) {
		tcp_recv_skb(sk, seq, &offset);
1677
		tcp_cleanup_rbuf(sk, copied);
1678
	}
L
Linus Torvalds 已提交
1679 1680
	return copied;
}
E
Eric Dumazet 已提交
1681
EXPORT_SYMBOL(tcp_read_sock);
L
Linus Torvalds 已提交
1682

1683 1684 1685 1686 1687 1688
int tcp_peek_len(struct socket *sock)
{
	return tcp_inq(sock->sk);
}
EXPORT_SYMBOL(tcp_peek_len);

1689 1690 1691
/* Make sure sk_rcvbuf is big enough to satisfy SO_RCVLOWAT hint */
int tcp_set_rcvlowat(struct sock *sk, int val)
{
1692 1693 1694 1695 1696 1697 1698
	int cap;

	if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
		cap = sk->sk_rcvbuf >> 1;
	else
		cap = sock_net(sk)->ipv4.sysctl_tcp_rmem[2] >> 1;
	val = min(val, cap);
1699
	sk->sk_rcvlowat = val ? : 1;
1700 1701 1702 1703

	/* Check if we need to signal EPOLLIN right now */
	tcp_data_ready(sk);

1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715
	if (sk->sk_userlocks & SOCK_RCVBUF_LOCK)
		return 0;

	val <<= 1;
	if (val > sk->sk_rcvbuf) {
		sk->sk_rcvbuf = val;
		tcp_sk(sk)->window_clamp = tcp_win_from_space(sk, val);
	}
	return 0;
}
EXPORT_SYMBOL(tcp_set_rcvlowat);

1716 1717 1718 1719
#ifdef CONFIG_MMU
static const struct vm_operations_struct tcp_vm_ops = {
};

1720 1721 1722
int tcp_mmap(struct file *file, struct socket *sock,
	     struct vm_area_struct *vma)
{
1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742
	if (vma->vm_flags & (VM_WRITE | VM_EXEC))
		return -EPERM;
	vma->vm_flags &= ~(VM_MAYWRITE | VM_MAYEXEC);

	/* Instruct vm_insert_page() to not down_read(mmap_sem) */
	vma->vm_flags |= VM_MIXEDMAP;

	vma->vm_ops = &tcp_vm_ops;
	return 0;
}
EXPORT_SYMBOL(tcp_mmap);

static int tcp_zerocopy_receive(struct sock *sk,
				struct tcp_zerocopy_receive *zc)
{
	unsigned long address = (unsigned long)zc->address;
	const skb_frag_t *frags = NULL;
	u32 length = 0, seq, offset;
	struct vm_area_struct *vma;
	struct sk_buff *skb = NULL;
1743
	struct tcp_sock *tp;
1744
	int inq;
1745 1746
	int ret;

1747
	if (address & (PAGE_SIZE - 1) || address != zc->address)
1748 1749 1750
		return -EINVAL;

	if (sk->sk_state == TCP_LISTEN)
1751
		return -ENOTCONN;
1752 1753 1754

	sock_rps_record_flow(sk);

1755 1756 1757 1758 1759
	down_read(&current->mm->mmap_sem);

	ret = -EINVAL;
	vma = find_vma(current->mm, address);
	if (!vma || vma->vm_start > address || vma->vm_ops != &tcp_vm_ops)
1760
		goto out;
1761 1762
	zc->length = min_t(unsigned long, zc->length, vma->vm_end - address);

1763 1764
	tp = tcp_sk(sk);
	seq = tp->copied_seq;
1765 1766
	inq = tcp_inq(sk);
	zc->length = min_t(u32, zc->length, inq);
1767
	zc->length &= ~(PAGE_SIZE - 1);
1768 1769 1770 1771 1772 1773
	if (zc->length) {
		zap_page_range(vma, address, zc->length);
		zc->recv_skip_hint = 0;
	} else {
		zc->recv_skip_hint = inq;
	}
1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794
	ret = 0;
	while (length + PAGE_SIZE <= zc->length) {
		if (zc->recv_skip_hint < PAGE_SIZE) {
			if (skb) {
				skb = skb->next;
				offset = seq - TCP_SKB_CB(skb)->seq;
			} else {
				skb = tcp_recv_skb(sk, seq, &offset);
			}

			zc->recv_skip_hint = skb->len - offset;
			offset -= skb_headlen(skb);
			if ((int)offset < 0 || skb_has_frag_list(skb))
				break;
			frags = skb_shinfo(skb)->frags;
			while (offset) {
				if (frags->size > offset)
					goto out;
				offset -= frags->size;
				frags++;
			}
1795
		}
1796 1797 1798 1799 1800 1801 1802 1803 1804
		if (frags->size != PAGE_SIZE || frags->page_offset) {
			int remaining = zc->recv_skip_hint;

			while (remaining && (frags->size != PAGE_SIZE ||
					     frags->page_offset)) {
				remaining -= frags->size;
				frags++;
			}
			zc->recv_skip_hint -= remaining;
1805
			break;
1806
		}
1807 1808
		ret = vm_insert_page(vma, address + length,
				     skb_frag_page(frags));
1809
		if (ret)
1810 1811 1812 1813 1814
			break;
		length += PAGE_SIZE;
		seq += PAGE_SIZE;
		zc->recv_skip_hint -= PAGE_SIZE;
		frags++;
1815 1816
	}
out:
1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832
	up_read(&current->mm->mmap_sem);
	if (length) {
		tp->copied_seq = seq;
		tcp_rcv_space_adjust(sk);

		/* Clean up data we have read: This will do ACK frames. */
		tcp_recv_skb(sk, seq, &offset);
		tcp_cleanup_rbuf(sk, length);
		ret = 0;
		if (length == zc->length)
			zc->recv_skip_hint = 0;
	} else {
		if (!zc->recv_skip_hint && sock_flag(sk, SOCK_DONE))
			ret = -EIO;
	}
	zc->length = length;
1833 1834
	return ret;
}
1835
#endif
1836

1837
static void tcp_update_recv_tstamps(struct sk_buff *skb,
D
Deepa Dinamani 已提交
1838
				    struct scm_timestamping_internal *tss)
1839 1840
{
	if (skb->tstamp)
D
Deepa Dinamani 已提交
1841
		tss->ts[0] = ktime_to_timespec64(skb->tstamp);
1842
	else
D
Deepa Dinamani 已提交
1843
		tss->ts[0] = (struct timespec64) {0};
1844 1845

	if (skb_hwtstamps(skb)->hwtstamp)
D
Deepa Dinamani 已提交
1846
		tss->ts[2] = ktime_to_timespec64(skb_hwtstamps(skb)->hwtstamp);
1847
	else
D
Deepa Dinamani 已提交
1848
		tss->ts[2] = (struct timespec64) {0};
1849 1850 1851
}

/* Similar to __sock_recv_timestamp, but does not require an skb */
1852
static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
D
Deepa Dinamani 已提交
1853
			       struct scm_timestamping_internal *tss)
1854
{
1855
	int new_tstamp = sock_flag(sk, SOCK_TSTAMP_NEW);
1856 1857 1858 1859 1860
	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)) {
1861 1862 1863 1864 1865 1866
				if (new_tstamp) {
					struct __kernel_timespec kts = {tss->ts[0].tv_sec, tss->ts[0].tv_nsec};

					put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_NEW,
						 sizeof(kts), &kts);
				} else {
D
Deepa Dinamani 已提交
1867 1868
					struct timespec ts_old = timespec64_to_timespec(tss->ts[0]);

1869
					put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMPNS_OLD,
D
Deepa Dinamani 已提交
1870
						 sizeof(ts_old), &ts_old);
1871
				}
1872
			} else {
1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887
				if (new_tstamp) {
					struct __kernel_sock_timeval stv;

					stv.tv_sec = tss->ts[0].tv_sec;
					stv.tv_usec = tss->ts[0].tv_nsec / 1000;
					put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_NEW,
						 sizeof(stv), &stv);
				} else {
					struct __kernel_old_timeval tv;

					tv.tv_sec = tss->ts[0].tv_sec;
					tv.tv_usec = tss->ts[0].tv_nsec / 1000;
					put_cmsg(msg, SOL_SOCKET, SO_TIMESTAMP_OLD,
						 sizeof(tv), &tv);
				}
1888 1889 1890 1891 1892 1893
			}
		}

		if (sk->sk_tsflags & SOF_TIMESTAMPING_SOFTWARE)
			has_timestamping = true;
		else
D
Deepa Dinamani 已提交
1894
			tss->ts[0] = (struct timespec64) {0};
1895 1896 1897 1898 1899 1900
	}

	if (tss->ts[2].tv_sec || tss->ts[2].tv_nsec) {
		if (sk->sk_tsflags & SOF_TIMESTAMPING_RAW_HARDWARE)
			has_timestamping = true;
		else
D
Deepa Dinamani 已提交
1901
			tss->ts[2] = (struct timespec64) {0};
1902 1903 1904
	}

	if (has_timestamping) {
D
Deepa Dinamani 已提交
1905 1906 1907 1908 1909
		tss->ts[1] = (struct timespec64) {0};
		if (sock_flag(sk, SOCK_TSTAMP_NEW))
			put_cmsg_scm_timestamping64(msg, tss);
		else
			put_cmsg_scm_timestamping(msg, tss);
1910 1911 1912
	}
}

1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925
static int tcp_inq_hint(struct sock *sk)
{
	const struct tcp_sock *tp = tcp_sk(sk);
	u32 copied_seq = READ_ONCE(tp->copied_seq);
	u32 rcv_nxt = READ_ONCE(tp->rcv_nxt);
	int inq;

	inq = rcv_nxt - copied_seq;
	if (unlikely(inq < 0 || copied_seq != READ_ONCE(tp->copied_seq))) {
		lock_sock(sk);
		inq = tp->rcv_nxt - tp->copied_seq;
		release_sock(sk);
	}
1926 1927 1928 1929 1930
	/* After receiving a FIN, tell the user-space to continue reading
	 * by returning a non-zero inq.
	 */
	if (inq == 0 && sock_flag(sk, SOCK_DONE))
		inq = 1;
1931 1932 1933
	return inq;
}

L
Linus Torvalds 已提交
1934 1935 1936 1937 1938 1939 1940 1941
/*
 *	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.
 */

1942 1943
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
1944 1945 1946 1947 1948 1949
{
	struct tcp_sock *tp = tcp_sk(sk);
	int copied = 0;
	u32 peek_seq;
	u32 *seq;
	unsigned long used;
1950
	int err, inq;
L
Linus Torvalds 已提交
1951 1952
	int target;		/* Read at least this many bytes */
	long timeo;
1953
	struct sk_buff *skb, *last;
I
Ilpo Järvinen 已提交
1954
	u32 urg_hole = 0;
D
Deepa Dinamani 已提交
1955
	struct scm_timestamping_internal tss;
1956
	bool has_tss = false;
1957
	bool has_cmsg;
L
Linus Torvalds 已提交
1958

1959
	if (unlikely(flags & MSG_ERRQUEUE))
1960
		return inet_recv_error(sk, msg, len, addr_len);
1961

1962 1963 1964
	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
	    (sk->sk_state == TCP_ESTABLISHED))
		sk_busy_loop(sk, nonblock);
1965

L
Linus Torvalds 已提交
1966 1967 1968 1969 1970 1971
	lock_sock(sk);

	err = -ENOTCONN;
	if (sk->sk_state == TCP_LISTEN)
		goto out;

1972
	has_cmsg = tp->recvmsg_inq;
L
Linus Torvalds 已提交
1973 1974 1975 1976 1977 1978
	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
1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993
	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
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016
	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. */

2017
		last = skb_peek_tail(&sk->sk_receive_queue);
2018
		skb_queue_walk(&sk->sk_receive_queue, skb) {
2019
			last = skb;
L
Linus Torvalds 已提交
2020 2021 2022
			/* Now that we have two receive queues this
			 * shouldn't happen.
			 */
2023
			if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
2024
				 "TCP recvmsg seq # bug: copied %X, seq %X, rcvnxt %X, fl %X\n",
J
Joe Perches 已提交
2025 2026
				 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
				 flags))
L
Linus Torvalds 已提交
2027
				break;
2028

L
Linus Torvalds 已提交
2029
			offset = *seq - TCP_SKB_CB(skb)->seq;
2030 2031
			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
2032
				offset--;
2033
			}
L
Linus Torvalds 已提交
2034 2035
			if (offset < skb->len)
				goto found_ok_skb;
2036
			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
2037
				goto found_fin_ok;
J
Joe Perches 已提交
2038
			WARN(!(flags & MSG_PEEK),
2039
			     "TCP recvmsg seq # bug 2: copied %X, seq %X, rcvnxt %X, fl %X\n",
J
Joe Perches 已提交
2040
			     *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
2041
		}
L
Linus Torvalds 已提交
2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052

		/* 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 ||
2053
			    signal_pending(current))
L
Linus Torvalds 已提交
2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067
				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) {
2068 2069 2070 2071
				/* This occurs when user tries to read
				 * from never connected socket.
				 */
				copied = -ENOTCONN;
L
Linus Torvalds 已提交
2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085
				break;
			}

			if (!timeo) {
				copied = -EAGAIN;
				break;
			}

			if (signal_pending(current)) {
				copied = sock_intr_errno(timeo);
				break;
			}
		}

2086
		tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
2087 2088 2089 2090 2091

		if (copied >= target) {
			/* Do not sleep, just process backlog. */
			release_sock(sk);
			lock_sock(sk);
2092 2093 2094
		} else {
			sk_wait_data(sk, &timeo, last);
		}
L
Linus Torvalds 已提交
2095

I
Ilpo Järvinen 已提交
2096 2097
		if ((flags & MSG_PEEK) &&
		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
2098 2099 2100
			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
2101 2102 2103 2104
			peek_seq = tp->copied_seq;
		}
		continue;

2105
found_ok_skb:
L
Linus Torvalds 已提交
2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117
		/* 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
2118
						urg_hole++;
L
Linus Torvalds 已提交
2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129
						offset++;
						used--;
						if (!used)
							goto skip_copy;
					}
				} else
					used = urg_offset;
			}
		}

		if (!(flags & MSG_TRUNC)) {
2130
			err = skb_copy_datagram_msg(skb, offset, msg, used);
D
Dan Williams 已提交
2131 2132 2133 2134 2135
			if (err) {
				/* Exception. Bailout! */
				if (!copied)
					copied = -EFAULT;
				break;
L
Linus Torvalds 已提交
2136 2137 2138 2139 2140 2141 2142 2143 2144 2145
			}
		}

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

		tcp_rcv_space_adjust(sk);

skip_copy:
2146
		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
L
Linus Torvalds 已提交
2147
			tp->urg_data = 0;
2148 2149
			tcp_fast_path_check(sk);
		}
L
Linus Torvalds 已提交
2150 2151 2152
		if (used + offset < skb->len)
			continue;

2153 2154 2155
		if (TCP_SKB_CB(skb)->has_rxtstamp) {
			tcp_update_recv_tstamps(skb, &tss);
			has_tss = true;
2156
			has_cmsg = true;
2157
		}
2158
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
2159
			goto found_fin_ok;
D
Dan Williams 已提交
2160 2161
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
2162 2163
		continue;

2164
found_fin_ok:
L
Linus Torvalds 已提交
2165 2166
		/* Process the FIN. */
		++*seq;
D
Dan Williams 已提交
2167 2168
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
2169 2170 2171 2172 2173 2174 2175 2176
		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
	 */

	/* Clean up data we have read: This will do ACK frames. */
2177
	tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
2178 2179

	release_sock(sk);
2180 2181 2182 2183 2184 2185 2186 2187 2188 2189

	if (has_cmsg) {
		if (has_tss)
			tcp_recv_timestamp(msg, sk, &tss);
		if (tp->recvmsg_inq) {
			inq = tcp_inq_hint(sk);
			put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq);
		}
	}

L
Linus Torvalds 已提交
2190 2191 2192 2193 2194 2195 2196
	return copied;

out:
	release_sock(sk);
	return err;

recv_urg:
2197
	err = tcp_recv_urg(sk, msg, len, flags);
L
Linus Torvalds 已提交
2198
	goto out;
P
Pavel Emelyanov 已提交
2199 2200 2201 2202

recv_sndq:
	err = tcp_peek_sndq(sk, msg, len);
	goto out;
L
Linus Torvalds 已提交
2203
}
E
Eric Dumazet 已提交
2204
EXPORT_SYMBOL(tcp_recvmsg);
L
Linus Torvalds 已提交
2205

I
Ilpo Järvinen 已提交
2206 2207 2208 2209
void tcp_set_state(struct sock *sk, int state)
{
	int oldstate = sk->sk_state;

L
Lawrence Brakmo 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
	/* We defined a new enum for TCP states that are exported in BPF
	 * so as not force the internal TCP states to be frozen. The
	 * following checks will detect if an internal state value ever
	 * differs from the BPF value. If this ever happens, then we will
	 * need to remap the internal value to the BPF value before calling
	 * tcp_call_bpf_2arg.
	 */
	BUILD_BUG_ON((int)BPF_TCP_ESTABLISHED != (int)TCP_ESTABLISHED);
	BUILD_BUG_ON((int)BPF_TCP_SYN_SENT != (int)TCP_SYN_SENT);
	BUILD_BUG_ON((int)BPF_TCP_SYN_RECV != (int)TCP_SYN_RECV);
	BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT1 != (int)TCP_FIN_WAIT1);
	BUILD_BUG_ON((int)BPF_TCP_FIN_WAIT2 != (int)TCP_FIN_WAIT2);
	BUILD_BUG_ON((int)BPF_TCP_TIME_WAIT != (int)TCP_TIME_WAIT);
	BUILD_BUG_ON((int)BPF_TCP_CLOSE != (int)TCP_CLOSE);
	BUILD_BUG_ON((int)BPF_TCP_CLOSE_WAIT != (int)TCP_CLOSE_WAIT);
	BUILD_BUG_ON((int)BPF_TCP_LAST_ACK != (int)TCP_LAST_ACK);
	BUILD_BUG_ON((int)BPF_TCP_LISTEN != (int)TCP_LISTEN);
	BUILD_BUG_ON((int)BPF_TCP_CLOSING != (int)TCP_CLOSING);
	BUILD_BUG_ON((int)BPF_TCP_NEW_SYN_RECV != (int)TCP_NEW_SYN_RECV);
	BUILD_BUG_ON((int)BPF_TCP_MAX_STATES != (int)TCP_MAX_STATES);

	if (BPF_SOCK_OPS_TEST_FLAG(tcp_sk(sk), BPF_SOCK_OPS_STATE_CB_FLAG))
		tcp_call_bpf_2arg(sk, BPF_SOCK_OPS_STATE_CB, oldstate, state);
2233

I
Ilpo Järvinen 已提交
2234 2235 2236
	switch (state) {
	case TCP_ESTABLISHED:
		if (oldstate != TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2237
			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2238 2239 2240 2241
		break;

	case TCP_CLOSE:
		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2242
			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
I
Ilpo Järvinen 已提交
2243 2244 2245 2246

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2247
			inet_put_port(sk);
I
Ilpo Järvinen 已提交
2248 2249
		/* fall through */
	default:
2250
		if (oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2251
			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2252 2253 2254 2255 2256
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
2257
	inet_sk_state_store(sk, state);
I
Ilpo Järvinen 已提交
2258 2259 2260
}
EXPORT_SYMBOL_GPL(tcp_set_state);

L
Linus Torvalds 已提交
2261 2262 2263 2264 2265 2266 2267
/*
 *	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.
 */

2268
static const unsigned char new_state[16] = {
L
Linus Torvalds 已提交
2269
  /* current state:        new state:      action:	*/
2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282
  [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
2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296
};

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
2297
 *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
L
Linus Torvalds 已提交
2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317
 */

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
2318
EXPORT_SYMBOL(tcp_shutdown);
L
Linus Torvalds 已提交
2319

A
Arun Sharma 已提交
2320 2321 2322 2323 2324 2325 2326
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);

2327 2328 2329 2330
	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
2331 2332 2333
	return too_many_orphans || out_of_socket_memory;
}

L
Linus Torvalds 已提交
2334 2335 2336 2337
void tcp_close(struct sock *sk, long timeout)
{
	struct sk_buff *skb;
	int data_was_unread = 0;
H
Herbert Xu 已提交
2338
	int state;
L
Linus Torvalds 已提交
2339 2340 2341 2342 2343 2344 2345 2346

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

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

		/* Special case. */
2347
		inet_csk_listen_stop(sk);
L
Linus Torvalds 已提交
2348 2349 2350 2351 2352 2353 2354 2355 2356

		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) {
2357 2358 2359 2360
		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
2361 2362 2363 2364
		data_was_unread += len;
		__kfree_skb(skb);
	}

2365
	sk_mem_reclaim(sk);
L
Linus Torvalds 已提交
2366

2367 2368 2369 2370
	/* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
	if (sk->sk_state == TCP_CLOSE)
		goto adjudge_to_death;

2371 2372 2373 2374 2375 2376
	/* 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
2377
	 */
P
Pavel Emelyanov 已提交
2378 2379 2380
	if (unlikely(tcp_sk(sk)->repair)) {
		sk->sk_prot->disconnect(sk, 0);
	} else if (data_was_unread) {
L
Linus Torvalds 已提交
2381
		/* Unread data was tossed, zap the connection. */
2382
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
L
Linus Torvalds 已提交
2383
		tcp_set_state(sk, TCP_CLOSE);
2384
		tcp_send_active_reset(sk, sk->sk_allocation);
L
Linus Torvalds 已提交
2385 2386 2387
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
2388
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
L
Linus Torvalds 已提交
2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413
	} 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
2414 2415 2416 2417
		 * 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
2418 2419 2420 2421 2422 2423 2424
		 */
		tcp_send_fin(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
H
Herbert Xu 已提交
2425 2426 2427 2428
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

L
Linus Torvalds 已提交
2429 2430
	local_bh_disable();
	bh_lock_sock(sk);
2431 2432
	/* remove backlog if any, without releasing ownership. */
	__release_sock(sk);
L
Linus Torvalds 已提交
2433

H
Herbert Xu 已提交
2434 2435
	percpu_counter_inc(sk->sk_prot->orphan_count);

H
Herbert Xu 已提交
2436 2437 2438
	/* 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
2439 2440 2441 2442

	/*	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.
2443
	 *	We use a 1 minute timeout (about the same as BSD) then kill
L
Linus Torvalds 已提交
2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458
	 *	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);
2459
			__NET_INC_STATS(sock_net(sk),
2460
					LINUX_MIB_TCPABORTONLINGER);
L
Linus Torvalds 已提交
2461
		} else {
2462
			const int tmo = tcp_fin_time(sk);
L
Linus Torvalds 已提交
2463 2464

			if (tmo > TCP_TIMEWAIT_LEN) {
2465 2466
				inet_csk_reset_keepalive_timer(sk,
						tmo - TCP_TIMEWAIT_LEN);
L
Linus Torvalds 已提交
2467 2468 2469 2470 2471 2472 2473
			} else {
				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
				goto out;
			}
		}
	}
	if (sk->sk_state != TCP_CLOSE) {
2474
		sk_mem_reclaim(sk);
A
Arun Sharma 已提交
2475
		if (tcp_check_oom(sk, 0)) {
L
Linus Torvalds 已提交
2476 2477
			tcp_set_state(sk, TCP_CLOSE);
			tcp_send_active_reset(sk, GFP_ATOMIC);
2478
			__NET_INC_STATS(sock_net(sk),
2479
					LINUX_MIB_TCPABORTONMEMORY);
2480 2481 2482
		} else if (!check_net(sock_net(sk))) {
			/* Not possible to send reset; just close */
			tcp_set_state(sk, TCP_CLOSE);
L
Linus Torvalds 已提交
2483 2484 2485
		}
	}

2486 2487 2488 2489 2490 2491
	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.
		 */
2492
		if (req)
2493
			reqsk_fastopen_remove(sk, req, false);
2494
		inet_csk_destroy_sock(sk);
2495
	}
L
Linus Torvalds 已提交
2496 2497 2498 2499 2500
	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
2501
	release_sock(sk);
L
Linus Torvalds 已提交
2502 2503
	sock_put(sk);
}
E
Eric Dumazet 已提交
2504
EXPORT_SYMBOL(tcp_close);
L
Linus Torvalds 已提交
2505 2506 2507

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

E
Eric Dumazet 已提交
2508
static inline bool tcp_need_reset(int state)
L
Linus Torvalds 已提交
2509 2510 2511 2512 2513 2514
{
	return (1 << state) &
	       (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
		TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
}

2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530
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);
	}
}

2531 2532 2533 2534 2535 2536 2537 2538 2539
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);
	}
2540
	tcp_rtx_queue_purge(sk);
E
Eric Dumazet 已提交
2541 2542 2543 2544 2545
	skb = sk->sk_tx_skb_cache;
	if (skb) {
		__kfree_skb(skb);
		sk->sk_tx_skb_cache = NULL;
	}
2546 2547 2548
	INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
	sk_mem_reclaim(sk);
	tcp_clear_all_retrans_hints(tcp_sk(sk));
2549
	tcp_sk(sk)->packets_out = 0;
2550
	inet_csk(sk)->icsk_backoff = 0;
2551 2552
}

L
Linus Torvalds 已提交
2553 2554 2555
int tcp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
2556
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2557 2558 2559 2560 2561 2562 2563 2564
	struct tcp_sock *tp = tcp_sk(sk);
	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) {
2565
		inet_csk_listen_stop(sk);
P
Pavel Emelyanov 已提交
2566 2567
	} else if (unlikely(tp->repair)) {
		sk->sk_err = ECONNABORTED;
L
Linus Torvalds 已提交
2568 2569 2570
	} 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
2571
		/* The last check adjusts for discrepancy of Linux wrt. RFC
L
Linus Torvalds 已提交
2572 2573 2574 2575 2576 2577 2578 2579 2580
		 * 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);
E
Eric Dumazet 已提交
2581 2582 2583 2584
	if (sk->sk_rx_skb_cache) {
		__kfree_skb(sk->sk_rx_skb_cache);
		sk->sk_rx_skb_cache = NULL;
	}
2585 2586
	tp->copied_seq = tp->rcv_nxt;
	tp->urg_data = 0;
2587
	tcp_write_queue_purge(sk);
2588
	tcp_fastopen_active_disable_ofo_check(sk);
2589
	skb_rbtree_purge(&tp->out_of_order_queue);
L
Linus Torvalds 已提交
2590

E
Eric Dumazet 已提交
2591
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
2592 2593 2594 2595 2596 2597

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

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);
2598
	tp->srtt_us = 0;
2599
	tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
2600
	tp->rcv_rtt_last_tsecr = 0;
2601 2602
	tp->write_seq += tp->max_window + 2;
	if (tp->write_seq == 0)
L
Linus Torvalds 已提交
2603
		tp->write_seq = 1;
2604
	icsk->icsk_backoff = 0;
L
Linus Torvalds 已提交
2605
	tp->snd_cwnd = 2;
2606
	icsk->icsk_probes_out = 0;
2607
	icsk->icsk_rto = TCP_TIMEOUT_INIT;
I
Ilpo Järvinen 已提交
2608
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
2609
	tp->snd_cwnd = TCP_INIT_CWND;
L
Linus Torvalds 已提交
2610
	tp->snd_cwnd_cnt = 0;
2611
	tp->window_clamp = 0;
2612
	tp->delivered_ce = 0;
2613
	tcp_set_ca_state(sk, TCP_CA_Open);
2614
	tp->is_sack_reneg = 0;
L
Linus Torvalds 已提交
2615
	tcp_clear_retrans(tp);
2616
	inet_csk_delack_init(sk);
2617 2618 2619 2620
	/* 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;
2621
	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
L
Linus Torvalds 已提交
2622
	__sk_dst_reset(sk);
2623 2624
	dst_release(sk->sk_rx_dst);
	sk->sk_rx_dst = NULL;
2625
	tcp_saved_syn_free(tp);
E
Eric Dumazet 已提交
2626
	tp->compressed_ack = 0;
W
Wei Wang 已提交
2627
	tp->bytes_sent = 0;
2628
	tp->bytes_retrans = 0;
2629 2630
	tp->duplicate_sack[0].start_seq = 0;
	tp->duplicate_sack[0].end_seq = 0;
W
Wei Wang 已提交
2631
	tp->dsack_dups = 0;
2632
	tp->reord_seen = 0;
2633 2634 2635 2636
	tp->retrans_out = 0;
	tp->sacked_out = 0;
	tp->tlp_high_seq = 0;
	tp->last_oow_ack_time = 0;
2637 2638
	/* There's a bubble in the pipe until at least the first ACK. */
	tp->app_limited = ~0U;
2639 2640 2641 2642 2643 2644
	tp->rack.mstamp = 0;
	tp->rack.advanced = 0;
	tp->rack.reo_wnd_steps = 1;
	tp->rack.last_delivered = 0;
	tp->rack.reo_wnd_persist = 0;
	tp->rack.dsack_seen = 0;
2645 2646 2647 2648
	tp->syn_data_acked = 0;
	tp->rx_opt.saw_tstamp = 0;
	tp->rx_opt.dsack = 0;
	tp->rx_opt.num_sacks = 0;
2649

L
Linus Torvalds 已提交
2650

2651 2652 2653 2654
	/* Clean up fastopen related fields */
	tcp_free_fastopen_req(tp);
	inet->defer_connect = 0;

E
Eric Dumazet 已提交
2655
	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
L
Linus Torvalds 已提交
2656

2657 2658 2659 2660 2661 2662
	if (sk->sk_frag.page) {
		put_page(sk->sk_frag.page);
		sk->sk_frag.page = NULL;
		sk->sk_frag.offset = 0;
	}

L
Linus Torvalds 已提交
2663
	sk->sk_error_report(sk);
Y
YueHaibing 已提交
2664
	return 0;
L
Linus Torvalds 已提交
2665
}
E
Eric Dumazet 已提交
2666
EXPORT_SYMBOL(tcp_disconnect);
L
Linus Torvalds 已提交
2667

E
Eric Dumazet 已提交
2668
static inline bool tcp_can_repair_sock(const struct sock *sk)
P
Pavel Emelyanov 已提交
2669
{
2670
	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2671
		(sk->sk_state != TCP_LISTEN);
P
Pavel Emelyanov 已提交
2672 2673
}

2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705
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;
}

2706
static int tcp_repair_options_est(struct sock *sk,
2707
		struct tcp_repair_opt __user *optbuf, unsigned int len)
2708
{
2709
	struct tcp_sock *tp = tcp_sk(sk);
2710
	struct tcp_repair_opt opt;
2711

2712 2713
	while (len >= sizeof(opt)) {
		if (copy_from_user(&opt, optbuf, sizeof(opt)))
2714 2715 2716
			return -EFAULT;

		optbuf++;
2717
		len -= sizeof(opt);
2718

2719 2720 2721
		switch (opt.opt_code) {
		case TCPOPT_MSS:
			tp->rx_opt.mss_clamp = opt.opt_val;
2722
			tcp_mtup_init(sk);
2723
			break;
2724
		case TCPOPT_WINDOW:
2725 2726 2727 2728
			{
				u16 snd_wscale = opt.opt_val & 0xFFFF;
				u16 rcv_wscale = opt.opt_val >> 16;

2729
				if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2730
					return -EFBIG;
2731

2732 2733 2734 2735
				tp->rx_opt.snd_wscale = snd_wscale;
				tp->rx_opt.rcv_wscale = rcv_wscale;
				tp->rx_opt.wscale_ok = 1;
			}
2736 2737
			break;
		case TCPOPT_SACK_PERM:
2738 2739 2740
			if (opt.opt_val != 0)
				return -EINVAL;

2741 2742 2743
			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
			break;
		case TCPOPT_TIMESTAMP:
2744 2745 2746
			if (opt.opt_val != 0)
				return -EINVAL;

2747 2748 2749 2750 2751 2752 2753 2754
			tp->rx_opt.tstamp_ok = 1;
			break;
		}
	}

	return 0;
}

L
Linus Torvalds 已提交
2755 2756 2757
/*
 *	Socket option code for TCP.
 */
2758
static int do_tcp_setsockopt(struct sock *sk, int level,
2759
		int optname, char __user *optval, unsigned int optlen)
L
Linus Torvalds 已提交
2760 2761
{
	struct tcp_sock *tp = tcp_sk(sk);
2762
	struct inet_connection_sock *icsk = inet_csk(sk);
2763
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2764 2765 2766
	int val;
	int err = 0;

2767 2768 2769
	/* These are data/string values, all the others are ints */
	switch (optname) {
	case TCP_CONGESTION: {
2770 2771 2772 2773 2774 2775
		char name[TCP_CA_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
2776
					min_t(long, TCP_CA_NAME_MAX-1, optlen));
2777 2778 2779 2780 2781
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
2782
		err = tcp_set_congestion_control(sk, name, true, true);
2783 2784 2785
		release_sock(sk);
		return err;
	}
D
Dave Watson 已提交
2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803
	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;
	}
2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814
	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));
	}
2815 2816 2817
	default:
		/* fallthru */
		break;
2818
	}
2819

L
Linus Torvalds 已提交
2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831
	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
2832 2833
		 * know which interface is going to be used
		 */
2834
		if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
L
Linus Torvalds 已提交
2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851
			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;
2852
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2853 2854 2855 2856 2857
		} else {
			tp->nonagle &= ~TCP_NAGLE_OFF;
		}
		break;

A
Andreas Petlund 已提交
2858 2859 2860 2861 2862 2863 2864
	case TCP_THIN_LINEAR_TIMEOUTS:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->thin_lto = val;
		break;

A
Andreas Petlund 已提交
2865 2866 2867 2868 2869
	case TCP_THIN_DUPACK:
		if (val < 0 || val > 1)
			err = -EINVAL;
		break;

P
Pavel Emelyanov 已提交
2870 2871 2872
	case TCP_REPAIR:
		if (!tcp_can_repair_sock(sk))
			err = -EPERM;
2873
		else if (val == TCP_REPAIR_ON) {
P
Pavel Emelyanov 已提交
2874 2875 2876
			tp->repair = 1;
			sk->sk_reuse = SK_FORCE_REUSE;
			tp->repair_queue = TCP_NO_QUEUE;
2877
		} else if (val == TCP_REPAIR_OFF) {
P
Pavel Emelyanov 已提交
2878 2879 2880
			tp->repair = 0;
			sk->sk_reuse = SK_NO_REUSE;
			tcp_send_window_probe(sk);
2881
		} else if (val == TCP_REPAIR_OFF_NO_WP) {
P
Pavel Emelyanov 已提交
2882 2883 2884 2885 2886 2887 2888 2889 2890 2891
			tp->repair = 0;
			sk->sk_reuse = SK_NO_REUSE;
		} else
			err = -EINVAL;

		break;

	case TCP_REPAIR_QUEUE:
		if (!tp->repair)
			err = -EPERM;
2892
		else if ((unsigned int)val < TCP_QUEUES_NR)
P
Pavel Emelyanov 已提交
2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908
			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;

2909 2910 2911 2912
	case TCP_REPAIR_OPTIONS:
		if (!tp->repair)
			err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
2913
			err = tcp_repair_options_est(sk,
2914 2915
					(struct tcp_repair_opt __user *)optval,
					optlen);
2916 2917 2918 2919
		else
			err = -EPERM;
		break;

L
Linus Torvalds 已提交
2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937
	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;
2938
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949
		}
		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))) {
2950
				u32 elapsed = keepalive_time_elapsed(tp);
L
Linus Torvalds 已提交
2951 2952 2953 2954
				if (tp->keepalive_time > elapsed)
					elapsed = tp->keepalive_time - elapsed;
				else
					elapsed = 0;
2955
				inet_csk_reset_keepalive_timer(sk, elapsed);
L
Linus Torvalds 已提交
2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974
			}
		}
		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
2975
			icsk->icsk_syn_retries = val;
L
Linus Torvalds 已提交
2976 2977
		break;

2978 2979 2980 2981 2982 2983 2984
	case TCP_SAVE_SYN:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->save_syn = val;
		break;

L
Linus Torvalds 已提交
2985 2986 2987
	case TCP_LINGER2:
		if (val < 0)
			tp->linger2 = -1;
2988
		else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
L
Linus Torvalds 已提交
2989 2990 2991 2992 2993 2994
			tp->linger2 = 0;
		else
			tp->linger2 = val * HZ;
		break;

	case TCP_DEFER_ACCEPT:
2995 2996 2997 2998
		/* 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
2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014
		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) {
W
Wei Wang 已提交
3015
			inet_csk_enter_pingpong_mode(sk);
L
Linus Torvalds 已提交
3016
		} else {
W
Wei Wang 已提交
3017
			inet_csk_exit_pingpong_mode(sk);
L
Linus Torvalds 已提交
3018 3019
			if ((1 << sk->sk_state) &
			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
3020 3021
			    inet_csk_ack_scheduled(sk)) {
				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
3022
				tcp_cleanup_rbuf(sk, 1);
L
Linus Torvalds 已提交
3023
				if (!(val & 1))
W
Wei Wang 已提交
3024
					inet_csk_enter_pingpong_mode(sk);
L
Linus Torvalds 已提交
3025 3026 3027 3028
			}
		}
		break;

3029 3030
#ifdef CONFIG_TCP_MD5SIG
	case TCP_MD5SIG:
3031
	case TCP_MD5SIG_EXT:
3032 3033 3034 3035
		if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))
			err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
		else
			err = -EINVAL;
3036 3037
		break;
#endif
3038
	case TCP_USER_TIMEOUT:
3039
		/* Cap the max time in ms TCP will retry or probe the window
3040 3041
		 * before giving up and aborting (ETIMEDOUT) a connection.
		 */
3042 3043 3044
		if (val < 0)
			err = -EINVAL;
		else
3045
			icsk->icsk_user_timeout = val;
3046
		break;
3047 3048 3049

	case TCP_FASTOPEN:
		if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
3050
		    TCPF_LISTEN))) {
3051
			tcp_fastopen_init_key_once(net);
3052

3053
			fastopen_queue_tune(sk, val);
3054
		} else {
3055
			err = -EINVAL;
3056
		}
3057
		break;
W
Wei Wang 已提交
3058 3059 3060
	case TCP_FASTOPEN_CONNECT:
		if (val > 1 || val < 0) {
			err = -EINVAL;
3061
		} else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
W
Wei Wang 已提交
3062 3063 3064 3065 3066 3067 3068 3069
			if (sk->sk_state == TCP_CLOSE)
				tp->fastopen_connect = val;
			else
				err = -EINVAL;
		} else {
			err = -EOPNOTSUPP;
		}
		break;
3070 3071 3072 3073 3074 3075 3076 3077
	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;
3078 3079 3080 3081
	case TCP_TIMESTAMP:
		if (!tp->repair)
			err = -EPERM;
		else
3082
			tp->tsoffset = val - tcp_time_stamp_raw();
3083
		break;
3084 3085 3086
	case TCP_REPAIR_WINDOW:
		err = tcp_repair_set_window(tp, optval, optlen);
		break;
3087 3088 3089 3090
	case TCP_NOTSENT_LOWAT:
		tp->notsent_lowat = val;
		sk->sk_write_space(sk);
		break;
3091 3092 3093 3094 3095 3096
	case TCP_INQ:
		if (val > 1 || val < 0)
			err = -EINVAL;
		else
			tp->recvmsg_inq = val;
		break;
L
Linus Torvalds 已提交
3097 3098 3099
	default:
		err = -ENOPROTOOPT;
		break;
3100 3101
	}

L
Linus Torvalds 已提交
3102 3103 3104 3105
	release_sock(sk);
	return err;
}

3106
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
3107
		   unsigned int optlen)
3108
{
3109
	const struct inet_connection_sock *icsk = inet_csk(sk);
3110 3111 3112 3113 3114 3115

	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
3116
EXPORT_SYMBOL(tcp_setsockopt);
3117 3118

#ifdef CONFIG_COMPAT
3119
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
3120
			  char __user *optval, unsigned int optlen)
3121
{
3122 3123 3124
	if (level != SOL_TCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
3125 3126
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
3127
EXPORT_SYMBOL(compat_tcp_setsockopt);
3128 3129
#endif

3130 3131 3132 3133 3134 3135 3136 3137 3138
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)
3139
			stats[i] += tcp_jiffies32 - tp->chrono_start;
3140 3141 3142 3143 3144 3145 3146 3147 3148
		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
3149
/* Return information about state of tcp endpoint in API format. */
3150
void tcp_get_info(struct sock *sk, struct tcp_info *info)
L
Linus Torvalds 已提交
3151
{
3152
	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
3153
	const struct inet_connection_sock *icsk = inet_csk(sk);
3154
	unsigned long rate;
3155
	u32 now;
3156
	u64 rate64;
3157
	bool slow;
L
Linus Torvalds 已提交
3158 3159

	memset(info, 0, sizeof(*info));
3160 3161
	if (sk->sk_type != SOCK_STREAM)
		return;
L
Linus Torvalds 已提交
3162

3163
	info->tcpi_state = inet_sk_state_load(sk);
3164

3165 3166
	/* Report meaningful fields for all TCP states, including listeners */
	rate = READ_ONCE(sk->sk_pacing_rate);
3167
	rate64 = (rate != ~0UL) ? rate : ~0ULL;
3168
	info->tcpi_pacing_rate = rate64;
3169 3170

	rate = READ_ONCE(sk->sk_max_pacing_rate);
3171
	rate64 = (rate != ~0UL) ? rate : ~0ULL;
3172
	info->tcpi_max_pacing_rate = rate64;
3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185

	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;
	}
3186 3187 3188

	slow = lock_sock_fast(sk);

3189
	info->tcpi_ca_state = icsk->icsk_ca_state;
3190
	info->tcpi_retransmits = icsk->icsk_retransmits;
3191
	info->tcpi_probes = icsk->icsk_probes_out;
3192
	info->tcpi_backoff = icsk->icsk_backoff;
L
Linus Torvalds 已提交
3193 3194 3195

	if (tp->rx_opt.tstamp_ok)
		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
3196
	if (tcp_is_sack(tp))
L
Linus Torvalds 已提交
3197 3198 3199 3200 3201
		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;
3202
	}
L
Linus Torvalds 已提交
3203

E
Eric Dumazet 已提交
3204
	if (tp->ecn_flags & TCP_ECN_OK)
L
Linus Torvalds 已提交
3205
		info->tcpi_options |= TCPI_OPT_ECN;
E
Eric Dumazet 已提交
3206 3207
	if (tp->ecn_flags & TCP_ECN_SEEN)
		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Y
Yuchung Cheng 已提交
3208 3209
	if (tp->syn_data_acked)
		info->tcpi_options |= TCPI_OPT_SYN_DATA;
L
Linus Torvalds 已提交
3210

3211 3212
	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
3213
	info->tcpi_snd_mss = tp->mss_cache;
3214
	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
L
Linus Torvalds 已提交
3215

3216 3217 3218
	info->tcpi_unacked = tp->packets_out;
	info->tcpi_sacked = tp->sacked_out;

L
Linus Torvalds 已提交
3219 3220 3221
	info->tcpi_lost = tp->lost_out;
	info->tcpi_retrans = tp->retrans_out;

3222
	now = tcp_jiffies32;
L
Linus Torvalds 已提交
3223
	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
3224
	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
L
Linus Torvalds 已提交
3225 3226
	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);

3227
	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
L
Linus Torvalds 已提交
3228
	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
3229 3230
	info->tcpi_rtt = tp->srtt_us >> 3;
	info->tcpi_rttvar = tp->mdev_us >> 2;
L
Linus Torvalds 已提交
3231 3232 3233
	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
	info->tcpi_advmss = tp->advmss;

3234
	info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
L
Linus Torvalds 已提交
3235 3236 3237
	info->tcpi_rcv_space = tp->rcvq_space.space;

	info->tcpi_total_retrans = tp->total_retrans;
3238

3239 3240
	info->tcpi_bytes_acked = tp->bytes_acked;
	info->tcpi_bytes_received = tp->bytes_received;
3241
	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
3242
	tcp_get_info_chrono_stats(tp, info);
3243

3244 3245
	info->tcpi_segs_out = tp->segs_out;
	info->tcpi_segs_in = tp->segs_in;
3246 3247

	info->tcpi_min_rtt = tcp_min_rtt(tp);
3248 3249
	info->tcpi_data_segs_in = tp->data_segs_in;
	info->tcpi_data_segs_out = tp->data_segs_out;
Y
Yuchung Cheng 已提交
3250 3251

	info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
3252 3253
	rate64 = tcp_compute_delivery_rate(tp);
	if (rate64)
3254
		info->tcpi_delivery_rate = rate64;
3255 3256
	info->tcpi_delivered = tp->delivered;
	info->tcpi_delivered_ce = tp->delivered_ce;
W
Wei Wang 已提交
3257
	info->tcpi_bytes_sent = tp->bytes_sent;
3258
	info->tcpi_bytes_retrans = tp->bytes_retrans;
W
Wei Wang 已提交
3259
	info->tcpi_dsack_dups = tp->dsack_dups;
3260
	info->tcpi_reord_seen = tp->reord_seen;
3261
	unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
3262 3263 3264
}
EXPORT_SYMBOL_GPL(tcp_get_info);

3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284
static size_t tcp_opt_stats_get_size(void)
{
	return
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BUSY */
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_RWND_LIMITED */
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_SNDBUF_LIMITED */
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DATA_SEGS_OUT */
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_TOTAL_RETRANS */
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_PACING_RATE */
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_DELIVERY_RATE */
		nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_CWND */
		nla_total_size(sizeof(u32)) + /* TCP_NLA_REORDERING */
		nla_total_size(sizeof(u32)) + /* TCP_NLA_MIN_RTT */
		nla_total_size(sizeof(u8)) + /* TCP_NLA_RECUR_RETRANS */
		nla_total_size(sizeof(u8)) + /* TCP_NLA_DELIVERY_RATE_APP_LMT */
		nla_total_size(sizeof(u32)) + /* TCP_NLA_SNDQ_SIZE */
		nla_total_size(sizeof(u8)) + /* TCP_NLA_CA_STATE */
		nla_total_size(sizeof(u32)) + /* TCP_NLA_SND_SSTHRESH */
		nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED */
		nla_total_size(sizeof(u32)) + /* TCP_NLA_DELIVERED_CE */
W
Wei Wang 已提交
3285
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */
3286
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */
W
Wei Wang 已提交
3287
		nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */
3288
		nla_total_size(sizeof(u32)) + /* TCP_NLA_REORD_SEEN */
3289
		nla_total_size(sizeof(u32)) + /* TCP_NLA_SRTT */
3290 3291 3292
		0;
}

3293 3294 3295 3296 3297
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;
3298
	unsigned long rate;
3299
	u64 rate64;
3300

3301
	stats = alloc_skb(tcp_opt_stats_get_size(), GFP_ATOMIC);
3302 3303 3304 3305 3306 3307 3308 3309 3310 3311
	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);
3312 3313 3314 3315
	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);
3316 3317

	rate = READ_ONCE(sk->sk_pacing_rate);
3318
	rate64 = (rate != ~0UL) ? rate : ~0ULL;
3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329
	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);
3330
	nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, tp->snd_ssthresh);
3331 3332
	nla_put_u32(stats, TCP_NLA_DELIVERED, tp->delivered);
	nla_put_u32(stats, TCP_NLA_DELIVERED_CE, tp->delivered_ce);
3333 3334

	nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una);
3335
	nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state);
3336

W
Wei Wang 已提交
3337 3338
	nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, tp->bytes_sent,
			  TCP_NLA_PAD);
3339 3340
	nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans,
			  TCP_NLA_PAD);
W
Wei Wang 已提交
3341
	nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups);
3342
	nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen);
3343
	nla_put_u32(stats, TCP_NLA_SRTT, tp->srtt_us >> 3);
W
Wei Wang 已提交
3344

3345 3346 3347
	return stats;
}

3348 3349
static int do_tcp_getsockopt(struct sock *sk, int level,
		int optname, char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
3350
{
3351
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
3352
	struct tcp_sock *tp = tcp_sk(sk);
3353
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365
	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:
3366
		val = tp->mss_cache;
L
Linus Torvalds 已提交
3367 3368
		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			val = tp->rx_opt.user_mss;
3369 3370
		if (tp->repair)
			val = tp->rx_opt.mss_clamp;
L
Linus Torvalds 已提交
3371 3372 3373 3374 3375 3376 3377 3378
		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
3379
		val = keepalive_time_when(tp) / HZ;
L
Linus Torvalds 已提交
3380 3381
		break;
	case TCP_KEEPINTVL:
E
Eric Dumazet 已提交
3382
		val = keepalive_intvl_when(tp) / HZ;
L
Linus Torvalds 已提交
3383 3384
		break;
	case TCP_KEEPCNT:
E
Eric Dumazet 已提交
3385
		val = keepalive_probes(tp);
L
Linus Torvalds 已提交
3386 3387
		break;
	case TCP_SYNCNT:
3388
		val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
L
Linus Torvalds 已提交
3389 3390 3391 3392
		break;
	case TCP_LINGER2:
		val = tp->linger2;
		if (val >= 0)
3393
			val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
L
Linus Torvalds 已提交
3394 3395
		break;
	case TCP_DEFER_ACCEPT:
3396 3397
		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
3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416
		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;
	}
3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436
	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
3437
	case TCP_QUICKACK:
W
Wei Wang 已提交
3438
		val = !inet_csk_in_pingpong_mode(sk);
L
Linus Torvalds 已提交
3439
		break;
3440 3441 3442 3443 3444 3445 3446

	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;
3447
		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
3448 3449
			return -EFAULT;
		return 0;
3450

D
Dave Watson 已提交
3451 3452 3453 3454
	case TCP_ULP:
		if (get_user(len, optlen))
			return -EFAULT;
		len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
3455 3456 3457 3458 3459
		if (!icsk->icsk_ulp_ops) {
			if (put_user(0, optlen))
				return -EFAULT;
			return 0;
		}
D
Dave Watson 已提交
3460 3461 3462 3463 3464 3465
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len))
			return -EFAULT;
		return 0;

3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487
	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;
	}
3488 3489 3490
	case TCP_THIN_LINEAR_TIMEOUTS:
		val = tp->thin_lto;
		break;
Y
Yuchung Cheng 已提交
3491

3492
	case TCP_THIN_DUPACK:
Y
Yuchung Cheng 已提交
3493
		val = 0;
3494
		break;
3495

P
Pavel Emelyanov 已提交
3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506
	case TCP_REPAIR:
		val = tp->repair;
		break;

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

3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528
	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
3529 3530 3531 3532 3533 3534 3535 3536 3537
	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;

3538
	case TCP_USER_TIMEOUT:
3539
		val = icsk->icsk_user_timeout;
3540
		break;
3541 3542

	case TCP_FASTOPEN:
3543
		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3544 3545
		break;

W
Wei Wang 已提交
3546 3547 3548 3549
	case TCP_FASTOPEN_CONNECT:
		val = tp->fastopen_connect;
		break;

3550 3551 3552 3553
	case TCP_FASTOPEN_NO_COOKIE:
		val = tp->fastopen_no_cookie;
		break;

3554
	case TCP_TIMESTAMP:
3555
		val = tcp_time_stamp_raw() + tp->tsoffset;
3556
		break;
3557 3558 3559
	case TCP_NOTSENT_LOWAT:
		val = tp->notsent_lowat;
		break;
3560 3561 3562
	case TCP_INQ:
		val = tp->recvmsg_inq;
		break;
3563 3564 3565 3566 3567 3568 3569 3570 3571
	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) {
3572 3573 3574 3575 3576 3577 3578 3579 3580
			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];
3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598
			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;
	}
3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617
#ifdef CONFIG_MMU
	case TCP_ZEROCOPY_RECEIVE: {
		struct tcp_zerocopy_receive zc;
		int err;

		if (get_user(len, optlen))
			return -EFAULT;
		if (len != sizeof(zc))
			return -EINVAL;
		if (copy_from_user(&zc, optval, len))
			return -EFAULT;
		lock_sock(sk);
		err = tcp_zerocopy_receive(sk, &zc);
		release_sock(sk);
		if (!err && copy_to_user(optval, &zc, len))
			err = -EFAULT;
		return err;
	}
#endif
L
Linus Torvalds 已提交
3618 3619
	default:
		return -ENOPROTOOPT;
3620
	}
L
Linus Torvalds 已提交
3621 3622 3623 3624 3625 3626 3627 3628

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

3629 3630 3631 3632 3633 3634 3635 3636 3637 3638
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
3639
EXPORT_SYMBOL(tcp_getsockopt);
3640 3641

#ifdef CONFIG_COMPAT
3642 3643
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
			  char __user *optval, int __user *optlen)
3644
{
3645 3646 3647
	if (level != SOL_TCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
3648 3649
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
3650
EXPORT_SYMBOL(compat_tcp_getsockopt);
3651
#endif
L
Linus Torvalds 已提交
3652

3653
#ifdef CONFIG_TCP_MD5SIG
E
Eric Dumazet 已提交
3654
static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3655
static DEFINE_MUTEX(tcp_md5sig_mutex);
E
Eric Dumazet 已提交
3656
static bool tcp_md5sig_pool_populated = false;
3657

3658
static void __tcp_alloc_md5sig_pool(void)
3659
{
H
Herbert Xu 已提交
3660
	struct crypto_ahash *hash;
3661 3662
	int cpu;

H
Herbert Xu 已提交
3663
	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3664
	if (IS_ERR(hash))
H
Herbert Xu 已提交
3665 3666
		return;

3667
	for_each_possible_cpu(cpu) {
3668
		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
H
Herbert Xu 已提交
3669
		struct ahash_request *req;
3670

3671 3672 3673 3674 3675 3676 3677 3678 3679
		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
3680 3681 3682 3683 3684 3685 3686 3687 3688 3689
		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;
3690
	}
E
Eric Dumazet 已提交
3691 3692
	/* before setting tcp_md5sig_pool_populated, we must commit all writes
	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3693 3694
	 */
	smp_wmb();
E
Eric Dumazet 已提交
3695
	tcp_md5sig_pool_populated = true;
3696 3697
}

3698
bool tcp_alloc_md5sig_pool(void)
3699
{
E
Eric Dumazet 已提交
3700
	if (unlikely(!tcp_md5sig_pool_populated)) {
3701 3702
		mutex_lock(&tcp_md5sig_mutex);

3703
		if (!tcp_md5sig_pool_populated) {
3704
			__tcp_alloc_md5sig_pool();
3705
			if (tcp_md5sig_pool_populated)
3706
				static_branch_inc(&tcp_md5_needed);
3707
		}
3708 3709

		mutex_unlock(&tcp_md5sig_mutex);
3710
	}
E
Eric Dumazet 已提交
3711
	return tcp_md5sig_pool_populated;
3712 3713 3714
}
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);

E
Eric Dumazet 已提交
3715 3716 3717 3718 3719 3720 3721 3722 3723

/**
 *	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)
3724
{
E
Eric Dumazet 已提交
3725
	local_bh_disable();
3726

E
Eric Dumazet 已提交
3727 3728 3729 3730 3731
	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
3732 3733 3734 3735
	local_bh_enable();
	return NULL;
}
EXPORT_SYMBOL(tcp_get_md5sig_pool);
3736

3737
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3738
			  const struct sk_buff *skb, unsigned int header_len)
3739 3740 3741
{
	struct scatterlist sg;
	const struct tcphdr *tp = tcp_hdr(skb);
H
Herbert Xu 已提交
3742
	struct ahash_request *req = hp->md5_req;
3743 3744 3745
	unsigned int i;
	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
					   skb_headlen(skb) - header_len : 0;
3746
	const struct skb_shared_info *shi = skb_shinfo(skb);
3747
	struct sk_buff *frag_iter;
3748 3749 3750 3751

	sg_init_table(&sg, 1);

	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
H
Herbert Xu 已提交
3752 3753
	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
	if (crypto_ahash_update(req))
3754 3755 3756 3757
		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
3758 3759 3760 3761 3762
		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
3763 3764
		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
		if (crypto_ahash_update(req))
3765 3766 3767
			return 1;
	}

3768 3769 3770 3771
	skb_walk_frags(skb, frag_iter)
		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
			return 1;

3772 3773 3774 3775
	return 0;
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

3776
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3777 3778 3779 3780
{
	struct scatterlist sg;

	sg_init_one(&sg, key->key, key->keylen);
H
Herbert Xu 已提交
3781 3782
	ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
	return crypto_ahash_update(hp->md5_req);
3783 3784 3785
}
EXPORT_SYMBOL(tcp_md5_hash_key);

3786 3787
#endif

A
Andi Kleen 已提交
3788 3789
void tcp_done(struct sock *sk)
{
3790 3791
	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;

3792
	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3793
		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
A
Andi Kleen 已提交
3794 3795 3796

	tcp_set_state(sk, TCP_CLOSE);
	tcp_clear_xmit_timers(sk);
3797
	if (req)
3798
		reqsk_fastopen_remove(sk, req, false);
A
Andi Kleen 已提交
3799 3800 3801 3802 3803 3804 3805 3806 3807 3808

	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);

3809 3810 3811
int tcp_abort(struct sock *sk, int err)
{
	if (!sk_fullsock(sk)) {
3812 3813 3814 3815
		if (sk->sk_state == TCP_NEW_SYN_RECV) {
			struct request_sock *req = inet_reqsk(sk);

			local_bh_disable();
3816
			inet_csk_reqsk_queue_drop(req->rsk_listener, req);
3817 3818 3819
			local_bh_enable();
			return 0;
		}
3820 3821 3822 3823 3824 3825
		return -EOPNOTSUPP;
	}

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

3826 3827 3828 3829 3830
	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);
		inet_csk_listen_stop(sk);
	}

3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846
	/* 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();
3847
	tcp_write_queue_purge(sk);
3848 3849 3850 3851 3852
	release_sock(sk);
	return 0;
}
EXPORT_SYMBOL_GPL(tcp_abort);

3853
extern struct tcp_congestion_ops tcp_reno;
L
Linus Torvalds 已提交
3854 3855 3856 3857

static __initdata unsigned long thash_entries;
static int __init set_thash_entries(char *str)
{
3858 3859
	ssize_t ret;

L
Linus Torvalds 已提交
3860 3861
	if (!str)
		return 0;
3862 3863 3864 3865 3866

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

L
Linus Torvalds 已提交
3867 3868 3869 3870
	return 1;
}
__setup("thash_entries=", set_thash_entries);

F
Fabian Frederick 已提交
3871
static void __init tcp_init_mem(void)
3872
{
E
Eric Dumazet 已提交
3873 3874
	unsigned long limit = nr_free_buffer_pages() / 16;

3875
	limit = max(limit, 128UL);
E
Eric Dumazet 已提交
3876 3877 3878
	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 % */
3879 3880
}

L
Linus Torvalds 已提交
3881 3882
void __init tcp_init(void)
{
3883
	int max_rshare, max_wshare, cnt;
3884
	unsigned long limit;
3885
	unsigned int i;
L
Linus Torvalds 已提交
3886

3887 3888
	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
L
Linus Torvalds 已提交
3889

3890 3891
	percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
	percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3892
	inet_hashinfo_init(&tcp_hashinfo);
3893 3894 3895
	inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash",
			    thash_entries, 21,  /* one slot per 2 MB*/
			    0, 64 * 1024);
3896 3897 3898
	tcp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("tcp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
3899
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
3900 3901 3902 3903 3904 3905

	/* Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
3906
	tcp_hashinfo.ehash =
L
Linus Torvalds 已提交
3907
		alloc_large_system_hash("TCP established",
3908
					sizeof(struct inet_ehash_bucket),
L
Linus Torvalds 已提交
3909
					thash_entries,
E
Eric Dumazet 已提交
3910
					17, /* one slot per 128 KB of memory */
3911
					0,
L
Linus Torvalds 已提交
3912
					NULL,
3913
					&tcp_hashinfo.ehash_mask,
3914
					0,
3915
					thash_entries ? 0 : 512 * 1024);
E
Eric Dumazet 已提交
3916
	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3917
		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
E
Eric Dumazet 已提交
3918

3919 3920
	if (inet_ehash_locks_alloc(&tcp_hashinfo))
		panic("TCP: failed to alloc ehash_locks");
3921
	tcp_hashinfo.bhash =
L
Linus Torvalds 已提交
3922
		alloc_large_system_hash("TCP bind",
3923
					sizeof(struct inet_bind_hashbucket),
3924
					tcp_hashinfo.ehash_mask + 1,
E
Eric Dumazet 已提交
3925
					17, /* one slot per 128 KB of memory */
3926
					0,
3927
					&tcp_hashinfo.bhash_size,
L
Linus Torvalds 已提交
3928
					NULL,
3929
					0,
L
Linus Torvalds 已提交
3930
					64 * 1024);
3931
	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3932 3933 3934
	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
3935 3936
	}

E
Eric Dumazet 已提交
3937 3938 3939

	cnt = tcp_hashinfo.ehash_mask + 1;
	sysctl_tcp_max_orphans = cnt / 2;
L
Linus Torvalds 已提交
3940

3941
	tcp_init_mem();
3942
	/* Set per-socket limits to no more than 1/128 the pressure threshold */
E
Eric Dumazet 已提交
3943
	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3944 3945
	max_wshare = min(4UL*1024*1024, limit);
	max_rshare = min(6UL*1024*1024, limit);
3946

3947 3948 3949
	init_net.ipv4.sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
	init_net.ipv4.sysctl_tcp_wmem[1] = 16*1024;
	init_net.ipv4.sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
3950

3951
	init_net.ipv4.sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3952 3953
	init_net.ipv4.sysctl_tcp_rmem[1] = 131072;
	init_net.ipv4.sysctl_tcp_rmem[2] = max(131072, max_rshare);
L
Linus Torvalds 已提交
3954

3955
	pr_info("Hash tables configured (established %u bind %u)\n",
J
Joe Perches 已提交
3956
		tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3957

3958
	tcp_v4_init();
3959
	tcp_metrics_init();
3960
	BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
E
Eric Dumazet 已提交
3961
	tcp_tasklet_init();
L
Linus Torvalds 已提交
3962
}