tcp.c 101.0 KB
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/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Implementation of the Transmission Control Protocol(TCP).
 *
8
 * Authors:	Ross Biro
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 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Mark Evans, <evansmp@uhura.aston.ac.uk>
 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
 *		Florian La Roche, <flla@stud.uni-sb.de>
 *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
 *		Linus Torvalds, <torvalds@cs.helsinki.fi>
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *		Matthew Dillon, <dillon@apollo.west.oic.com>
 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
 *		Jorge Cwik, <jorge@laser.satlink.net>
 *
 * Fixes:
 *		Alan Cox	:	Numerous verify_area() calls
 *		Alan Cox	:	Set the ACK bit on a reset
 *		Alan Cox	:	Stopped it crashing if it closed while
 *					sk->inuse=1 and was trying to connect
 *					(tcp_err()).
 *		Alan Cox	:	All icmp error handling was broken
 *					pointers passed where wrong and the
 *					socket was looked up backwards. Nobody
 *					tested any icmp error code obviously.
 *		Alan Cox	:	tcp_err() now handled properly. It
 *					wakes people on errors. poll
 *					behaves and the icmp error race
 *					has gone by moving it into sock.c
 *		Alan Cox	:	tcp_send_reset() fixed to work for
 *					everything not just packets for
 *					unknown sockets.
 *		Alan Cox	:	tcp option processing.
 *		Alan Cox	:	Reset tweaked (still not 100%) [Had
 *					syn rule wrong]
 *		Herp Rosmanith  :	More reset fixes
 *		Alan Cox	:	No longer acks invalid rst frames.
 *					Acking any kind of RST is right out.
 *		Alan Cox	:	Sets an ignore me flag on an rst
 *					receive otherwise odd bits of prattle
 *					escape still
 *		Alan Cox	:	Fixed another acking RST frame bug.
 *					Should stop LAN workplace lockups.
 *		Alan Cox	: 	Some tidyups using the new skb list
 *					facilities
 *		Alan Cox	:	sk->keepopen now seems to work
 *		Alan Cox	:	Pulls options out correctly on accepts
 *		Alan Cox	:	Fixed assorted sk->rqueue->next errors
 *		Alan Cox	:	PSH doesn't end a TCP read. Switched a
 *					bit to skb ops.
 *		Alan Cox	:	Tidied tcp_data to avoid a potential
 *					nasty.
 *		Alan Cox	:	Added some better commenting, as the
 *					tcp is hard to follow
 *		Alan Cox	:	Removed incorrect check for 20 * psh
 *	Michael O'Reilly	:	ack < copied bug fix.
 *	Johannes Stille		:	Misc tcp fixes (not all in yet).
 *		Alan Cox	:	FIN with no memory -> CRASH
 *		Alan Cox	:	Added socket option proto entries.
 *					Also added awareness of them to accept.
 *		Alan Cox	:	Added TCP options (SOL_TCP)
 *		Alan Cox	:	Switched wakeup calls to callbacks,
 *					so the kernel can layer network
 *					sockets.
 *		Alan Cox	:	Use ip_tos/ip_ttl settings.
 *		Alan Cox	:	Handle FIN (more) properly (we hope).
 *		Alan Cox	:	RST frames sent on unsynchronised
 *					state ack error.
 *		Alan Cox	:	Put in missing check for SYN bit.
 *		Alan Cox	:	Added tcp_select_window() aka NET2E
 *					window non shrink trick.
 *		Alan Cox	:	Added a couple of small NET2E timer
 *					fixes
 *		Charles Hedrick :	TCP fixes
 *		Toomas Tamm	:	TCP window fixes
 *		Alan Cox	:	Small URG fix to rlogin ^C ack fight
 *		Charles Hedrick	:	Rewrote most of it to actually work
 *		Linus		:	Rewrote tcp_read() and URG handling
 *					completely
 *		Gerhard Koerting:	Fixed some missing timer handling
 *		Matthew Dillon  :	Reworked TCP machine states as per RFC
 *		Gerhard Koerting:	PC/TCP workarounds
 *		Adam Caldwell	:	Assorted timer/timing errors
 *		Matthew Dillon	:	Fixed another RST bug
 *		Alan Cox	:	Move to kernel side addressing changes.
 *		Alan Cox	:	Beginning work on TCP fastpathing
 *					(not yet usable)
 *		Arnt Gulbrandsen:	Turbocharged tcp_check() routine.
 *		Alan Cox	:	TCP fast path debugging
 *		Alan Cox	:	Window clamping
 *		Michael Riepe	:	Bug in tcp_check()
 *		Matt Dillon	:	More TCP improvements and RST bug fixes
 *		Matt Dillon	:	Yet more small nasties remove from the
 *					TCP code (Be very nice to this man if
 *					tcp finally works 100%) 8)
 *		Alan Cox	:	BSD accept semantics.
 *		Alan Cox	:	Reset on closedown bug.
 *	Peter De Schrijver	:	ENOTCONN check missing in tcp_sendto().
 *		Michael Pall	:	Handle poll() after URG properly in
 *					all cases.
 *		Michael Pall	:	Undo the last fix in tcp_read_urg()
 *					(multi URG PUSH broke rlogin).
 *		Michael Pall	:	Fix the multi URG PUSH problem in
 *					tcp_readable(), poll() after URG
 *					works now.
 *		Michael Pall	:	recv(...,MSG_OOB) never blocks in the
 *					BSD api.
 *		Alan Cox	:	Changed the semantics of sk->socket to
 *					fix a race and a signal problem with
 *					accept() and async I/O.
 *		Alan Cox	:	Relaxed the rules on tcp_sendto().
 *		Yury Shevchuk	:	Really fixed accept() blocking problem.
 *		Craig I. Hagan  :	Allow for BSD compatible TIME_WAIT for
 *					clients/servers which listen in on
 *					fixed ports.
 *		Alan Cox	:	Cleaned the above up and shrank it to
 *					a sensible code size.
 *		Alan Cox	:	Self connect lockup fix.
 *		Alan Cox	:	No connect to multicast.
 *		Ross Biro	:	Close unaccepted children on master
 *					socket close.
 *		Alan Cox	:	Reset tracing code.
 *		Alan Cox	:	Spurious resets on shutdown.
 *		Alan Cox	:	Giant 15 minute/60 second timer error
 *		Alan Cox	:	Small whoops in polling before an
 *					accept.
 *		Alan Cox	:	Kept the state trace facility since
 *					it's handy for debugging.
 *		Alan Cox	:	More reset handler fixes.
 *		Alan Cox	:	Started rewriting the code based on
 *					the RFC's for other useful protocol
 *					references see: Comer, KA9Q NOS, and
 *					for a reference on the difference
 *					between specifications and how BSD
 *					works see the 4.4lite source.
 *		A.N.Kuznetsov	:	Don't time wait on completion of tidy
 *					close.
 *		Linus Torvalds	:	Fin/Shutdown & copied_seq changes.
 *		Linus Torvalds	:	Fixed BSD port reuse to work first syn
 *		Alan Cox	:	Reimplemented timers as per the RFC
 *					and using multiple timers for sanity.
 *		Alan Cox	:	Small bug fixes, and a lot of new
 *					comments.
 *		Alan Cox	:	Fixed dual reader crash by locking
 *					the buffers (much like datagram.c)
 *		Alan Cox	:	Fixed stuck sockets in probe. A probe
 *					now gets fed up of retrying without
 *					(even a no space) answer.
 *		Alan Cox	:	Extracted closing code better
 *		Alan Cox	:	Fixed the closing state machine to
 *					resemble the RFC.
 *		Alan Cox	:	More 'per spec' fixes.
 *		Jorge Cwik	:	Even faster checksumming.
 *		Alan Cox	:	tcp_data() doesn't ack illegal PSH
 *					only frames. At least one pc tcp stack
 *					generates them.
 *		Alan Cox	:	Cache last socket.
 *		Alan Cox	:	Per route irtt.
 *		Matt Day	:	poll()->select() match BSD precisely on error
 *		Alan Cox	:	New buffers
 *		Marc Tamsky	:	Various sk->prot->retransmits and
 *					sk->retransmits misupdating fixed.
 *					Fixed tcp_write_timeout: stuck close,
 *					and TCP syn retries gets used now.
 *		Mark Yarvis	:	In tcp_read_wakeup(), don't send an
 *					ack if state is TCP_CLOSED.
 *		Alan Cox	:	Look up device on a retransmit - routes may
 *					change. Doesn't yet cope with MSS shrink right
 *					but it's a start!
 *		Marc Tamsky	:	Closing in closing fixes.
 *		Mike Shaver	:	RFC1122 verifications.
 *		Alan Cox	:	rcv_saddr errors.
 *		Alan Cox	:	Block double connect().
 *		Alan Cox	:	Small hooks for enSKIP.
 *		Alexey Kuznetsov:	Path MTU discovery.
 *		Alan Cox	:	Support soft errors.
 *		Alan Cox	:	Fix MTU discovery pathological case
 *					when the remote claims no mtu!
 *		Marc Tamsky	:	TCP_CLOSE fix.
 *		Colin (G3TNE)	:	Send a reset on syn ack replies in
 *					window but wrong (fixes NT lpd problems)
 *		Pedro Roque	:	Better TCP window handling, delayed ack.
 *		Joerg Reuter	:	No modification of locked buffers in
 *					tcp_do_retransmit()
 *		Eric Schenk	:	Changed receiver side silly window
 *					avoidance algorithm to BSD style
 *					algorithm. This doubles throughput
 *					against machines running Solaris,
 *					and seems to result in general
 *					improvement.
 *	Stefan Magdalinski	:	adjusted tcp_readable() to fix FIONREAD
 *	Willy Konynenberg	:	Transparent proxying support.
 *	Mike McLagan		:	Routing by source
 *		Keith Owens	:	Do proper merging with partial SKB's in
 *					tcp_do_sendmsg to avoid burstiness.
 *		Eric Schenk	:	Fix fast close down bug with
 *					shutdown() followed by close().
 *		Andi Kleen 	:	Make poll agree with SIGIO
 *	Salvatore Sanfilippo	:	Support SO_LINGER with linger == 1 and
 *					lingertime == 0 (RFC 793 ABORT Call)
 *	Hirokazu Takahashi	:	Use copy_from_user() instead of
 *					csum_and_copy_from_user() if possible.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or(at your option) any later version.
 *
 * Description of States:
 *
 *	TCP_SYN_SENT		sent a connection request, waiting for ack
 *
 *	TCP_SYN_RECV		received a connection request, sent ack,
 *				waiting for final ack in three-way handshake.
 *
 *	TCP_ESTABLISHED		connection established
 *
 *	TCP_FIN_WAIT1		our side has shutdown, waiting to complete
 *				transmission of remaining buffered data
 *
 *	TCP_FIN_WAIT2		all buffered data sent, waiting for remote
 *				to shutdown
 *
 *	TCP_CLOSING		both sides have shutdown but we still have
 *				data we have to finish sending
 *
 *	TCP_TIME_WAIT		timeout to catch resent junk before entering
 *				closed, can only be entered from FIN_WAIT2
 *				or CLOSING.  Required because the other end
 *				may not have gotten our last ACK causing it
 *				to retransmit the data packet (which we ignore)
 *
 *	TCP_CLOSE_WAIT		remote side has shutdown and is waiting for
 *				us to finish writing our data and to shutdown
 *				(we have to close() to move on to LAST_ACK)
 *
 *	TCP_LAST_ACK		out side has shutdown after remote has
 *				shutdown.  There may still be data in our
 *				buffer that we have to finish sending
 *
 *	TCP_CLOSE		socket is finished
 */

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#define pr_fmt(fmt) "TCP: " fmt

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#include <crypto/hash.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
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#include <linux/inet_diag.h>
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#include <linux/init.h>
#include <linux/fs.h>
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#include <linux/skbuff.h>
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#include <linux/scatterlist.h>
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#include <linux/splice.h>
#include <linux/net.h>
#include <linux/socket.h>
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#include <linux/random.h>
#include <linux/bootmem.h>
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#include <linux/highmem.h>
#include <linux/swap.h>
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#include <linux/cache.h>
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#include <linux/err.h>
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#include <linux/time.h>
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#include <linux/slab.h>
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#include <linux/errqueue.h>
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#include <linux/static_key.h>
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#include <net/icmp.h>
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#include <net/inet_common.h>
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#include <net/tcp.h>
#include <net/xfrm.h>
#include <net/ip.h>
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#include <net/sock.h>
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#include <linux/uaccess.h>
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#include <asm/ioctls.h>
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#include <net/busy_poll.h>
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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)
865 866 867 868 869 870
{
	struct sk_buff *skb;

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

871 872 873
	if (unlikely(tcp_under_memory_pressure(sk)))
		sk_mem_reclaim_partial(sk);

874
	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
875
	if (likely(skb)) {
876
		bool mem_scheduled;
877

878 879
		if (force_schedule) {
			mem_scheduled = true;
880 881
			sk_forced_mem_schedule(sk, skb->truesize);
		} else {
882
			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
883
		}
884
		if (likely(mem_scheduled)) {
885
			skb_reserve(skb, sk->sk_prot->max_header);
886 887 888 889
			/*
			 * Make sure that we have exactly size bytes
			 * available to the caller, no more, no less.
			 */
E
Eric Dumazet 已提交
890
			skb->reserved_tailroom = skb->end - skb->tail - size;
891
			INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
892 893 894 895
			return skb;
		}
		__kfree_skb(skb);
	} else {
896
		sk->sk_prot->enter_memory_pressure(sk);
897 898 899 900 901
		sk_stream_moderate_sndbuf(sk);
	}
	return NULL;
}

I
Ilpo Järvinen 已提交
902 903 904 905
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
				       int large_allowed)
{
	struct tcp_sock *tp = tcp_sk(sk);
906
	u32 new_size_goal, size_goal;
E
Eric Dumazet 已提交
907

E
Eric Dumazet 已提交
908
	if (!large_allowed)
E
Eric Dumazet 已提交
909 910
		return mss_now;

911 912
	/* 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
913 914 915 916 917 918 919 920 921
	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
922 923
	}

E
Eric Dumazet 已提交
924
	return max(size_goal, mss_now);
I
Ilpo Järvinen 已提交
925 926 927 928 929 930 931 932 933 934 935 936
}

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;
}

937 938
ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
			 size_t size, int flags)
L
Linus Torvalds 已提交
939 940
{
	struct tcp_sock *tp = tcp_sk(sk);
941
	int mss_now, size_goal;
L
Linus Torvalds 已提交
942 943 944 945
	int err;
	ssize_t copied;
	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

946 947 948 949 950 951
	/* 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)) {
952 953
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
954
			goto out_err;
955
	}
L
Linus Torvalds 已提交
956

957
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
958

I
Ilpo Järvinen 已提交
959
	mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
960 961 962 963
	copied = 0;

	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
964
		goto out_err;
L
Linus Torvalds 已提交
965

966
	while (size > 0) {
967
		struct sk_buff *skb = tcp_write_queue_tail(sk);
968 969
		int copy, i;
		bool can_coalesce;
L
Linus Torvalds 已提交
970

971
		if (!skb || (copy = size_goal - skb->len) <= 0 ||
972
		    !tcp_skb_can_collapse_to(skb)) {
L
Linus Torvalds 已提交
973 974 975 976
new_segment:
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;

977
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
978
					tcp_rtx_and_write_queues_empty(sk));
L
Linus Torvalds 已提交
979 980 981
			if (!skb)
				goto wait_for_memory;

982
			skb_entail(sk, skb);
983
			copy = size_goal;
L
Linus Torvalds 已提交
984 985 986 987 988 989 990
		}

		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
991
		if (!can_coalesce && i >= sysctl_max_skb_frags) {
L
Linus Torvalds 已提交
992 993 994
			tcp_mark_push(tp, skb);
			goto new_segment;
		}
995
		if (!sk_wmem_schedule(sk, copy))
L
Linus Torvalds 已提交
996
			goto wait_for_memory;
997

L
Linus Torvalds 已提交
998
		if (can_coalesce) {
E
Eric Dumazet 已提交
999
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
L
Linus Torvalds 已提交
1000 1001 1002 1003
		} else {
			get_page(page);
			skb_fill_page_desc(skb, i, page, offset, copy);
		}
1004 1005 1006

		if (!(flags & MSG_NO_SHARED_FRAGS))
			skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1007

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

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

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

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

		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
1032
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1033
		} else if (skb == tcp_send_head(sk))
L
Linus Torvalds 已提交
1034 1035 1036 1037 1038 1039
			tcp_push_one(sk, mss_now);
		continue;

wait_for_sndbuf:
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
wait_for_memory:
E
Eric Dumazet 已提交
1040 1041
		tcp_push(sk, flags & ~MSG_MORE, mss_now,
			 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1042

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

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

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

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

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

1078 1079
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1080 1081
	return do_tcp_sendpages(sk, page, offset, size, flags);
}
1082
EXPORT_SYMBOL_GPL(tcp_sendpage_locked);
1083 1084 1085 1086 1087 1088 1089 1090

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
1091
	release_sock(sk);
1092 1093

	return ret;
L
Linus Torvalds 已提交
1094
}
E
Eric Dumazet 已提交
1095
EXPORT_SYMBOL(tcp_sendpage);
L
Linus Torvalds 已提交
1096

1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113
/* Do not bother using a page frag for very small frames.
 * But use this heuristic only for the first skb in write queue.
 *
 * Having no payload in skb->head allows better SACK shifting
 * in tcp_shift_skb_data(), reducing sack/rack overhead, because
 * write queue has less skbs.
 * Each skb can hold up to MAX_SKB_FRAGS * 32Kbytes, or ~0.5 MB.
 * This also speeds up tso_fragment(), since it wont fallback
 * to tcp_fragment().
 */
static int linear_payload_sz(bool first_skb)
{
	if (first_skb)
		return SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER);
	return 0;
}

E
Eric Dumazet 已提交
1114
static int select_size(bool first_skb, bool zc)
L
Linus Torvalds 已提交
1115
{
E
Eric Dumazet 已提交
1116 1117 1118
	if (zc)
		return 0;
	return linear_payload_sz(first_skb);
L
Linus Torvalds 已提交
1119 1120
}

1121 1122
void tcp_free_fastopen_req(struct tcp_sock *tp)
{
1123
	if (tp->fastopen_req) {
1124 1125 1126 1127 1128
		kfree(tp->fastopen_req);
		tp->fastopen_req = NULL;
	}
}

1129 1130
static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
				int *copied, size_t size)
1131 1132
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Wei Wang 已提交
1133
	struct inet_sock *inet = inet_sk(sk);
1134
	struct sockaddr *uaddr = msg->msg_name;
1135 1136
	int err, flags;

1137
	if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
1138 1139
	    (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
	     uaddr->sa_family == AF_UNSPEC))
1140
		return -EOPNOTSUPP;
1141
	if (tp->fastopen_req)
1142 1143 1144 1145
		return -EALREADY; /* Another Fast Open is in progress */

	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
				   sk->sk_allocation);
1146
	if (unlikely(!tp->fastopen_req))
1147 1148
		return -ENOBUFS;
	tp->fastopen_req->data = msg;
1149
	tp->fastopen_req->size = size;
1150

W
Wei Wang 已提交
1151 1152 1153 1154 1155 1156 1157 1158 1159
	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;
		}
	}
1160
	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1161
	err = __inet_stream_connect(sk->sk_socket, uaddr,
1162
				    msg->msg_namelen, flags, 1);
1163 1164 1165 1166 1167 1168 1169 1170
	/* 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;
	}
1171 1172 1173
	return err;
}

1174
int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
L
Linus Torvalds 已提交
1175 1176
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Willem de Bruijn 已提交
1177
	struct ubuf_info *uarg = NULL;
L
Linus Torvalds 已提交
1178
	struct sk_buff *skb;
1179
	struct sockcm_cookie sockc;
1180 1181
	int flags, err, copied = 0;
	int mss_now = 0, size_goal, copied_syn = 0;
1182
	bool process_backlog = false;
E
Eric Dumazet 已提交
1183
	bool zc = false;
L
Linus Torvalds 已提交
1184 1185 1186
	long timeo;

	flags = msg->msg_flags;
W
Willem de Bruijn 已提交
1187

1188
	if (flags & MSG_ZEROCOPY && size && sock_flag(sk, SOCK_ZEROCOPY)) {
W
Willem de Bruijn 已提交
1189 1190 1191 1192 1193
		if (sk->sk_state != TCP_ESTABLISHED) {
			err = -EINVAL;
			goto out_err;
		}

1194
		skb = tcp_write_queue_tail(sk);
W
Willem de Bruijn 已提交
1195 1196 1197 1198 1199 1200
		uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb));
		if (!uarg) {
			err = -ENOBUFS;
			goto out_err;
		}

E
Eric Dumazet 已提交
1201
		zc = sk->sk_route_caps & NETIF_F_SG;
1202
		if (!zc)
W
Willem de Bruijn 已提交
1203 1204 1205
			uarg->zerocopy = 0;
	}

1206 1207
	if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect) &&
	    !tp->repair) {
1208
		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1209 1210 1211 1212 1213 1214
		if (err == -EINPROGRESS && copied_syn > 0)
			goto out;
		else if (err)
			goto out_err;
	}

L
Linus Torvalds 已提交
1215 1216
	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

1217 1218
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1219 1220 1221 1222 1223 1224
	/* 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)) {
1225 1226
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
1227
			goto do_error;
1228
	}
L
Linus Torvalds 已提交
1229

P
Pavel Emelyanov 已提交
1230 1231 1232
	if (unlikely(tp->repair)) {
		if (tp->repair_queue == TCP_RECV_QUEUE) {
			copied = tcp_send_rcvq(sk, msg, size);
1233
			goto out_nopush;
P
Pavel Emelyanov 已提交
1234 1235 1236 1237 1238 1239 1240 1241 1242
		}

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

		/* 'common' sending to sendq */
	}

1243
	sockcm_init(&sockc, sk);
1244 1245 1246 1247 1248 1249 1250 1251
	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
1252
	/* This should be in poll */
1253
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
1254 1255 1256 1257

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

1258 1259 1260
restart:
	mss_now = tcp_send_mss(sk, &size_goal, flags);

L
Linus Torvalds 已提交
1261 1262
	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1263
		goto do_error;
L
Linus Torvalds 已提交
1264

A
Al Viro 已提交
1265
	while (msg_data_left(msg)) {
1266
		int copy = 0;
L
Linus Torvalds 已提交
1267

1268
		skb = tcp_write_queue_tail(sk);
1269 1270
		if (skb)
			copy = size_goal - skb->len;
L
Linus Torvalds 已提交
1271

1272
		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1273
			bool first_skb;
1274
			int linear;
1275

L
Linus Torvalds 已提交
1276
new_segment:
1277 1278
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;
L
Linus Torvalds 已提交
1279

1280 1281
			if (process_backlog && sk_flush_backlog(sk)) {
				process_backlog = false;
1282
				goto restart;
1283
			}
1284
			first_skb = tcp_rtx_and_write_queues_empty(sk);
E
Eric Dumazet 已提交
1285
			linear = select_size(first_skb, zc);
1286
			skb = sk_stream_alloc_skb(sk, linear, sk->sk_allocation,
1287
						  first_skb);
1288 1289
			if (!skb)
				goto wait_for_memory;
L
Linus Torvalds 已提交
1290

1291
			process_backlog = true;
E
Eric Dumazet 已提交
1292
			skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1293

1294 1295
			skb_entail(sk, skb);
			copy = size_goal;
1296

1297 1298 1299 1300 1301 1302 1303
			/* All packets are restored as if they have
			 * already been sent. skb_mstamp isn't set to
			 * avoid wrong rtt estimation.
			 */
			if (tp->repair)
				TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED;
		}
L
Linus Torvalds 已提交
1304

1305
		/* Try to append data to the end of skb. */
A
Al Viro 已提交
1306 1307
		if (copy > msg_data_left(msg))
			copy = msg_data_left(msg);
1308 1309

		/* Where to copy to? */
1310
		if (skb_availroom(skb) > 0 && !zc) {
1311 1312 1313 1314 1315
			/* 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;
1316
		} else if (!zc) {
1317 1318 1319 1320 1321 1322
			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;
1323

1324 1325
			if (!skb_can_coalesce(skb, i, pfrag->page,
					      pfrag->offset)) {
E
Eric Dumazet 已提交
1326
				if (i >= sysctl_max_skb_frags) {
1327 1328
					tcp_mark_push(tp, skb);
					goto new_segment;
L
Linus Torvalds 已提交
1329
				}
1330
				merge = false;
L
Linus Torvalds 已提交
1331 1332
			}

1333 1334 1335 1336
			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
1337

1338 1339 1340 1341 1342 1343
			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
1344

1345 1346 1347 1348 1349 1350
			/* 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);
1351
				page_ref_inc(pfrag->page);
1352
			}
1353
			pfrag->offset += copy;
W
Willem de Bruijn 已提交
1354 1355
		} else {
			err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
W
Willem de Bruijn 已提交
1356 1357
			if (err == -EMSGSIZE || err == -EEXIST) {
				tcp_mark_push(tp, skb);
W
Willem de Bruijn 已提交
1358
				goto new_segment;
W
Willem de Bruijn 已提交
1359
			}
W
Willem de Bruijn 已提交
1360 1361 1362
			if (err < 0)
				goto do_error;
			copy = err;
1363 1364 1365 1366 1367 1368 1369 1370
		}

		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
1371

1372
		copied += copy;
A
Al Viro 已提交
1373
		if (!msg_data_left(msg)) {
1374 1375
			if (unlikely(flags & MSG_EOR))
				TCP_SKB_CB(skb)->eor = 1;
1376 1377
			goto out;
		}
L
Linus Torvalds 已提交
1378

1379
		if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair))
L
Linus Torvalds 已提交
1380 1381
			continue;

1382 1383 1384 1385 1386 1387 1388
		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
1389
wait_for_sndbuf:
1390
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
L
Linus Torvalds 已提交
1391
wait_for_memory:
1392 1393 1394
		if (copied)
			tcp_push(sk, flags & ~MSG_MORE, mss_now,
				 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1395

1396 1397
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
1398
			goto do_error;
L
Linus Torvalds 已提交
1399

1400
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1401 1402 1403
	}

out:
1404
	if (copied) {
E
Eric Dumazet 已提交
1405
		tcp_tx_timestamp(sk, sockc.tsflags);
E
Eric Dumazet 已提交
1406
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1407
	}
1408
out_nopush:
W
Willem de Bruijn 已提交
1409
	sock_zerocopy_put(uarg);
1410
	return copied + copied_syn;
L
Linus Torvalds 已提交
1411 1412 1413

do_fault:
	if (!skb->len) {
1414 1415 1416 1417 1418
		tcp_unlink_write_queue(skb, sk);
		/* It is the one place in all of TCP, except connection
		 * reset, where we can be unlinking the send_head.
		 */
		tcp_check_send_head(sk, skb);
1419
		sk_wmem_free_skb(sk, skb);
L
Linus Torvalds 已提交
1420 1421 1422
	}

do_error:
1423
	if (copied + copied_syn)
L
Linus Torvalds 已提交
1424 1425
		goto out;
out_err:
W
Willem de Bruijn 已提交
1426
	sock_zerocopy_put_abort(uarg);
L
Linus Torvalds 已提交
1427
	err = sk_stream_error(sk, flags, err);
1428
	/* make sure we wake any epoll edge trigger waiter */
1429 1430
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1431
		sk->sk_write_space(sk);
1432 1433
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1434 1435
	return err;
}
1436
EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447

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
1448
EXPORT_SYMBOL(tcp_sendmsg);
L
Linus Torvalds 已提交
1449 1450 1451 1452 1453 1454

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

1455
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
L
Linus Torvalds 已提交
1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478
{
	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
1479
				err = memcpy_to_msg(msg, &c, 1);
L
Linus Torvalds 已提交
1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498
			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
1499 1500 1501 1502 1503 1504 1505
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 */

1506 1507 1508 1509 1510 1511 1512
	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
1513
	skb_queue_walk(&sk->sk_write_queue, skb) {
1514
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
P
Pavel Emelyanov 已提交
1515 1516 1517 1518 1519 1520 1521 1522 1523
		if (err)
			break;

		copied += skb->len;
	}

	return err ?: copied;
}

L
Linus Torvalds 已提交
1524 1525 1526 1527 1528 1529
/* 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.
 */
1530
static void tcp_cleanup_rbuf(struct sock *sk, int copied)
L
Linus Torvalds 已提交
1531 1532
{
	struct tcp_sock *tp = tcp_sk(sk);
E
Eric Dumazet 已提交
1533
	bool time_to_ack = false;
L
Linus Torvalds 已提交
1534 1535 1536

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

1537
	WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
J
Joe Perches 已提交
1538
	     "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1539
	     tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
L
Linus Torvalds 已提交
1540

1541 1542
	if (inet_csk_ack_scheduled(sk)) {
		const struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1543 1544
		   /* Delayed ACKs frequently hit locked sockets during bulk
		    * receive. */
1545
		if (icsk->icsk_ack.blocked ||
L
Linus Torvalds 已提交
1546
		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
1547
		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
L
Linus Torvalds 已提交
1548 1549 1550 1551 1552 1553
		    /*
		     * 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.
		     */
1554 1555 1556 1557 1558
		    (copied > 0 &&
		     ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED2) ||
		      ((icsk->icsk_ack.pending & ICSK_ACK_PUSHED) &&
		       !icsk->icsk_ack.pingpong)) &&
		      !atomic_read(&sk->sk_rmem_alloc)))
E
Eric Dumazet 已提交
1559
			time_to_ack = true;
L
Linus Torvalds 已提交
1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580
	}

	/* 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
1581
				time_to_ack = true;
L
Linus Torvalds 已提交
1582 1583 1584 1585 1586 1587
		}
	}
	if (time_to_ack)
		tcp_send_ack(sk);
}

1588
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
L
Linus Torvalds 已提交
1589 1590 1591 1592
{
	struct sk_buff *skb;
	u32 offset;

1593
	while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
L
Linus Torvalds 已提交
1594
		offset = seq - TCP_SKB_CB(skb)->seq;
1595 1596
		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
1597
			offset--;
1598
		}
1599
		if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
L
Linus Torvalds 已提交
1600 1601 1602
			*off = offset;
			return skb;
		}
1603 1604 1605 1606
		/* 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
1607
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635
	}
	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) {
1636 1637
			int used;
			size_t len;
L
Linus Torvalds 已提交
1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648

			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);
1649
			if (used <= 0) {
1650 1651 1652 1653
				if (!copied)
					copied = used;
				break;
			} else if (used <= len) {
L
Linus Torvalds 已提交
1654 1655 1656 1657
				seq += used;
				copied += used;
				offset += used;
			}
1658
			/* If recv_actor drops the lock (e.g. TCP splice
1659 1660 1661 1662
			 * receive) the skb pointer might be invalid when
			 * getting here: tcp_collapse might have deleted it
			 * while aggregating skbs from the socket queue.
			 */
1663 1664
			skb = tcp_recv_skb(sk, seq - 1, &offset);
			if (!skb)
L
Linus Torvalds 已提交
1665
				break;
1666 1667 1668 1669 1670
			/* 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
1671
		}
1672
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
D
Dan Williams 已提交
1673
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1674 1675 1676
			++seq;
			break;
		}
D
Dan Williams 已提交
1677
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1678 1679
		if (!desc->count)
			break;
1680
		tp->copied_seq = seq;
L
Linus Torvalds 已提交
1681 1682 1683 1684 1685 1686
	}
	tp->copied_seq = seq;

	tcp_rcv_space_adjust(sk);

	/* Clean up data we have read: This will do ACK frames. */
1687 1688
	if (copied > 0) {
		tcp_recv_skb(sk, seq, &offset);
1689
		tcp_cleanup_rbuf(sk, copied);
1690
	}
L
Linus Torvalds 已提交
1691 1692
	return copied;
}
E
Eric Dumazet 已提交
1693
EXPORT_SYMBOL(tcp_read_sock);
L
Linus Torvalds 已提交
1694

1695 1696 1697 1698 1699 1700
int tcp_peek_len(struct socket *sock)
{
	return tcp_inq(sock->sk);
}
EXPORT_SYMBOL(tcp_peek_len);

1701 1702 1703
/* Make sure sk_rcvbuf is big enough to satisfy SO_RCVLOWAT hint */
int tcp_set_rcvlowat(struct sock *sk, int val)
{
1704 1705 1706 1707 1708 1709 1710
	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);
1711
	sk->sk_rcvlowat = val ? : 1;
1712 1713 1714 1715

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

1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727
	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);

1728 1729 1730 1731
#ifdef CONFIG_MMU
static const struct vm_operations_struct tcp_vm_ops = {
};

1732 1733 1734
int tcp_mmap(struct file *file, struct socket *sock,
	     struct vm_area_struct *vma)
{
1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754
	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;
1755 1756 1757
	struct tcp_sock *tp;
	int ret;

1758
	if (address & (PAGE_SIZE - 1) || address != zc->address)
1759 1760 1761
		return -EINVAL;

	if (sk->sk_state == TCP_LISTEN)
1762
		return -ENOTCONN;
1763 1764 1765

	sock_rps_record_flow(sk);

1766 1767 1768 1769 1770
	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)
1771
		goto out;
1772 1773
	zc->length = min_t(unsigned long, zc->length, vma->vm_end - address);

1774 1775
	tp = tcp_sk(sk);
	seq = tp->copied_seq;
1776 1777
	zc->length = min_t(u32, zc->length, tcp_inq(sk));
	zc->length &= ~(PAGE_SIZE - 1);
1778

1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802
	zap_page_range(vma, address, zc->length);

	zc->recv_skip_hint = 0;
	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++;
			}
1803
		}
1804 1805 1806 1807
		if (frags->size != PAGE_SIZE || frags->page_offset)
			break;
		ret = vm_insert_page(vma, address + length,
				     skb_frag_page(frags));
1808
		if (ret)
1809 1810 1811 1812 1813
			break;
		length += PAGE_SIZE;
		seq += PAGE_SIZE;
		zc->recv_skip_hint -= PAGE_SIZE;
		frags++;
1814 1815
	}
out:
1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831
	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;
1832 1833
	return ret;
}
1834
#endif
1835

1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850
static void tcp_update_recv_tstamps(struct sk_buff *skb,
				    struct scm_timestamping *tss)
{
	if (skb->tstamp)
		tss->ts[0] = ktime_to_timespec(skb->tstamp);
	else
		tss->ts[0] = (struct timespec) {0};

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

/* Similar to __sock_recv_timestamp, but does not require an skb */
1851 1852
static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
			       struct scm_timestamping *tss)
1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890
{
	struct timeval tv;
	bool has_timestamping = false;

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

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

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

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

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

1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906
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);
	}
	return inq;
}

L
Linus Torvalds 已提交
1907 1908 1909 1910 1911 1912 1913 1914
/*
 *	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.
 */

1915 1916
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
1917 1918 1919 1920 1921 1922
{
	struct tcp_sock *tp = tcp_sk(sk);
	int copied = 0;
	u32 peek_seq;
	u32 *seq;
	unsigned long used;
1923
	int err, inq;
L
Linus Torvalds 已提交
1924 1925
	int target;		/* Read at least this many bytes */
	long timeo;
1926
	struct sk_buff *skb, *last;
I
Ilpo Järvinen 已提交
1927
	u32 urg_hole = 0;
1928 1929
	struct scm_timestamping tss;
	bool has_tss = false;
1930
	bool has_cmsg;
L
Linus Torvalds 已提交
1931

1932
	if (unlikely(flags & MSG_ERRQUEUE))
1933
		return inet_recv_error(sk, msg, len, addr_len);
1934

1935 1936 1937
	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
	    (sk->sk_state == TCP_ESTABLISHED))
		sk_busy_loop(sk, nonblock);
1938

L
Linus Torvalds 已提交
1939 1940 1941 1942 1943 1944
	lock_sock(sk);

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

1945
	has_cmsg = tp->recvmsg_inq;
L
Linus Torvalds 已提交
1946 1947 1948 1949 1950 1951
	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
1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966
	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
1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989
	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. */

1990
		last = skb_peek_tail(&sk->sk_receive_queue);
1991
		skb_queue_walk(&sk->sk_receive_queue, skb) {
1992
			last = skb;
L
Linus Torvalds 已提交
1993 1994 1995
			/* Now that we have two receive queues this
			 * shouldn't happen.
			 */
1996
			if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
1997
				 "TCP recvmsg seq # bug: copied %X, seq %X, rcvnxt %X, fl %X\n",
J
Joe Perches 已提交
1998 1999
				 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
				 flags))
L
Linus Torvalds 已提交
2000
				break;
2001

L
Linus Torvalds 已提交
2002
			offset = *seq - TCP_SKB_CB(skb)->seq;
2003 2004
			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
2005
				offset--;
2006
			}
L
Linus Torvalds 已提交
2007 2008
			if (offset < skb->len)
				goto found_ok_skb;
2009
			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
2010
				goto found_fin_ok;
J
Joe Perches 已提交
2011
			WARN(!(flags & MSG_PEEK),
2012
			     "TCP recvmsg seq # bug 2: copied %X, seq %X, rcvnxt %X, fl %X\n",
J
Joe Perches 已提交
2013
			     *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
2014
		}
L
Linus Torvalds 已提交
2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

		/* 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 ||
2026
			    signal_pending(current))
L
Linus Torvalds 已提交
2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040
				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) {
2041 2042 2043 2044
				/* This occurs when user tries to read
				 * from never connected socket.
				 */
				copied = -ENOTCONN;
L
Linus Torvalds 已提交
2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058
				break;
			}

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

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

2059
		tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
2060 2061 2062 2063 2064

		if (copied >= target) {
			/* Do not sleep, just process backlog. */
			release_sock(sk);
			lock_sock(sk);
2065 2066 2067
		} else {
			sk_wait_data(sk, &timeo, last);
		}
L
Linus Torvalds 已提交
2068

I
Ilpo Järvinen 已提交
2069 2070
		if ((flags & MSG_PEEK) &&
		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
2071 2072 2073
			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
2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090
			peek_seq = tp->copied_seq;
		}
		continue;

	found_ok_skb:
		/* Ok so how much can we use? */
		used = skb->len - offset;
		if (len < used)
			used = len;

		/* Do we have urgent data here? */
		if (tp->urg_data) {
			u32 urg_offset = tp->urg_seq - *seq;
			if (urg_offset < used) {
				if (!urg_offset) {
					if (!sock_flag(sk, SOCK_URGINLINE)) {
						++*seq;
I
Ilpo Järvinen 已提交
2091
						urg_hole++;
L
Linus Torvalds 已提交
2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102
						offset++;
						used--;
						if (!used)
							goto skip_copy;
					}
				} else
					used = urg_offset;
			}
		}

		if (!(flags & MSG_TRUNC)) {
2103
			err = skb_copy_datagram_msg(skb, offset, msg, used);
D
Dan Williams 已提交
2104 2105 2106 2107 2108
			if (err) {
				/* Exception. Bailout! */
				if (!copied)
					copied = -EFAULT;
				break;
L
Linus Torvalds 已提交
2109 2110 2111 2112 2113 2114 2115 2116 2117 2118
			}
		}

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

		tcp_rcv_space_adjust(sk);

skip_copy:
2119
		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
L
Linus Torvalds 已提交
2120
			tp->urg_data = 0;
2121 2122
			tcp_fast_path_check(sk);
		}
L
Linus Torvalds 已提交
2123 2124 2125
		if (used + offset < skb->len)
			continue;

2126 2127 2128
		if (TCP_SKB_CB(skb)->has_rxtstamp) {
			tcp_update_recv_tstamps(skb, &tss);
			has_tss = true;
2129
			has_cmsg = true;
2130
		}
2131
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
2132
			goto found_fin_ok;
D
Dan Williams 已提交
2133 2134
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
2135 2136 2137 2138 2139
		continue;

	found_fin_ok:
		/* Process the FIN. */
		++*seq;
D
Dan Williams 已提交
2140 2141
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
2142 2143 2144 2145 2146 2147 2148 2149
		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. */
2150
	tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
2151 2152

	release_sock(sk);
2153 2154 2155 2156 2157 2158 2159 2160 2161 2162

	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
2163 2164 2165 2166 2167 2168 2169
	return copied;

out:
	release_sock(sk);
	return err;

recv_urg:
2170
	err = tcp_recv_urg(sk, msg, len, flags);
L
Linus Torvalds 已提交
2171
	goto out;
P
Pavel Emelyanov 已提交
2172 2173 2174 2175

recv_sndq:
	err = tcp_peek_sndq(sk, msg, len);
	goto out;
L
Linus Torvalds 已提交
2176
}
E
Eric Dumazet 已提交
2177
EXPORT_SYMBOL(tcp_recvmsg);
L
Linus Torvalds 已提交
2178

I
Ilpo Järvinen 已提交
2179 2180 2181 2182
void tcp_set_state(struct sock *sk, int state)
{
	int oldstate = sk->sk_state;

L
Lawrence Brakmo 已提交
2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205
	/* 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);
2206

I
Ilpo Järvinen 已提交
2207 2208 2209
	switch (state) {
	case TCP_ESTABLISHED:
		if (oldstate != TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2210
			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2211 2212 2213 2214
		break;

	case TCP_CLOSE:
		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2215
			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
I
Ilpo Järvinen 已提交
2216 2217 2218 2219

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2220
			inet_put_port(sk);
I
Ilpo Järvinen 已提交
2221 2222
		/* fall through */
	default:
2223
		if (oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2224
			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2225 2226 2227 2228 2229
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
2230
	inet_sk_state_store(sk, state);
I
Ilpo Järvinen 已提交
2231 2232

#ifdef STATE_TRACE
2233
	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
I
Ilpo Järvinen 已提交
2234 2235 2236 2237
#endif
}
EXPORT_SYMBOL_GPL(tcp_set_state);

L
Linus Torvalds 已提交
2238 2239 2240 2241 2242 2243 2244
/*
 *	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.
 */

2245
static const unsigned char new_state[16] = {
L
Linus Torvalds 已提交
2246
  /* current state:        new state:      action:	*/
2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259
  [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
2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273
};

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
2274
 *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
L
Linus Torvalds 已提交
2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294
 */

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
2295
EXPORT_SYMBOL(tcp_shutdown);
L
Linus Torvalds 已提交
2296

A
Arun Sharma 已提交
2297 2298 2299 2300 2301 2302 2303
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);

2304 2305 2306 2307
	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
2308 2309 2310
	return too_many_orphans || out_of_socket_memory;
}

L
Linus Torvalds 已提交
2311 2312 2313 2314
void tcp_close(struct sock *sk, long timeout)
{
	struct sk_buff *skb;
	int data_was_unread = 0;
H
Herbert Xu 已提交
2315
	int state;
L
Linus Torvalds 已提交
2316 2317 2318 2319 2320 2321 2322 2323

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

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

		/* Special case. */
2324
		inet_csk_listen_stop(sk);
L
Linus Torvalds 已提交
2325 2326 2327 2328 2329 2330 2331 2332 2333

		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) {
2334 2335 2336 2337
		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
2338 2339 2340 2341
		data_was_unread += len;
		__kfree_skb(skb);
	}

2342
	sk_mem_reclaim(sk);
L
Linus Torvalds 已提交
2343

2344 2345 2346 2347
	/* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
	if (sk->sk_state == TCP_CLOSE)
		goto adjudge_to_death;

2348 2349 2350 2351 2352 2353
	/* 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
2354
	 */
P
Pavel Emelyanov 已提交
2355 2356 2357
	if (unlikely(tcp_sk(sk)->repair)) {
		sk->sk_prot->disconnect(sk, 0);
	} else if (data_was_unread) {
L
Linus Torvalds 已提交
2358
		/* Unread data was tossed, zap the connection. */
2359
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
L
Linus Torvalds 已提交
2360
		tcp_set_state(sk, TCP_CLOSE);
2361
		tcp_send_active_reset(sk, sk->sk_allocation);
L
Linus Torvalds 已提交
2362 2363 2364
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
2365
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
L
Linus Torvalds 已提交
2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390
	} 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
2391 2392 2393 2394
		 * 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
2395 2396 2397 2398 2399 2400 2401
		 */
		tcp_send_fin(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
H
Herbert Xu 已提交
2402 2403 2404 2405
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

L
Linus Torvalds 已提交
2406 2407 2408 2409 2410
	/* It is the last release_sock in its life. It will remove backlog. */
	release_sock(sk);


	/* Now socket is owned by kernel and we acquire BH lock
2411
	 *  to finish close. No need to check for user refs.
L
Linus Torvalds 已提交
2412 2413 2414
	 */
	local_bh_disable();
	bh_lock_sock(sk);
2415
	WARN_ON(sock_owned_by_user(sk));
L
Linus Torvalds 已提交
2416

H
Herbert Xu 已提交
2417 2418
	percpu_counter_inc(sk->sk_prot->orphan_count);

H
Herbert Xu 已提交
2419 2420 2421
	/* 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
2422 2423 2424 2425

	/*	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.
2426
	 *	We use a 1 minute timeout (about the same as BSD) then kill
L
Linus Torvalds 已提交
2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441
	 *	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);
2442
			__NET_INC_STATS(sock_net(sk),
2443
					LINUX_MIB_TCPABORTONLINGER);
L
Linus Torvalds 已提交
2444
		} else {
2445
			const int tmo = tcp_fin_time(sk);
L
Linus Torvalds 已提交
2446 2447

			if (tmo > TCP_TIMEWAIT_LEN) {
2448 2449
				inet_csk_reset_keepalive_timer(sk,
						tmo - TCP_TIMEWAIT_LEN);
L
Linus Torvalds 已提交
2450 2451 2452 2453 2454 2455 2456
			} else {
				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
				goto out;
			}
		}
	}
	if (sk->sk_state != TCP_CLOSE) {
2457
		sk_mem_reclaim(sk);
A
Arun Sharma 已提交
2458
		if (tcp_check_oom(sk, 0)) {
L
Linus Torvalds 已提交
2459 2460
			tcp_set_state(sk, TCP_CLOSE);
			tcp_send_active_reset(sk, GFP_ATOMIC);
2461
			__NET_INC_STATS(sock_net(sk),
2462
					LINUX_MIB_TCPABORTONMEMORY);
2463 2464 2465
		} 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
2466 2467 2468
		}
	}

2469 2470 2471 2472 2473 2474
	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.
		 */
2475
		if (req)
2476
			reqsk_fastopen_remove(sk, req, false);
2477
		inet_csk_destroy_sock(sk);
2478
	}
L
Linus Torvalds 已提交
2479 2480 2481 2482 2483 2484 2485
	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}
E
Eric Dumazet 已提交
2486
EXPORT_SYMBOL(tcp_close);
L
Linus Torvalds 已提交
2487 2488 2489

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

E
Eric Dumazet 已提交
2490
static inline bool tcp_need_reset(int state)
L
Linus Torvalds 已提交
2491 2492 2493 2494 2495 2496
{
	return (1 << state) &
	       (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
		TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
}

2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512
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);
	}
}

2513 2514 2515 2516 2517 2518 2519 2520 2521
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);
	}
2522
	tcp_rtx_queue_purge(sk);
2523 2524 2525
	INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
	sk_mem_reclaim(sk);
	tcp_clear_all_retrans_hints(tcp_sk(sk));
2526
	tcp_sk(sk)->packets_out = 0;
2527 2528
}

L
Linus Torvalds 已提交
2529 2530 2531
int tcp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
2532
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2533 2534 2535 2536 2537 2538 2539 2540
	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) {
2541
		inet_csk_listen_stop(sk);
P
Pavel Emelyanov 已提交
2542 2543
	} else if (unlikely(tp->repair)) {
		sk->sk_err = ECONNABORTED;
L
Linus Torvalds 已提交
2544 2545 2546
	} 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
2547
		/* The last check adjusts for discrepancy of Linux wrt. RFC
L
Linus Torvalds 已提交
2548 2549 2550 2551 2552 2553 2554 2555 2556
		 * 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);
2557 2558
	tp->copied_seq = tp->rcv_nxt;
	tp->urg_data = 0;
2559
	tcp_write_queue_purge(sk);
2560
	tcp_fastopen_active_disable_ofo_check(sk);
2561
	skb_rbtree_purge(&tp->out_of_order_queue);
L
Linus Torvalds 已提交
2562

E
Eric Dumazet 已提交
2563
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
2564 2565 2566 2567 2568 2569

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

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);
2570
	tp->srtt_us = 0;
2571
	tp->rcv_rtt_last_tsecr = 0;
2572 2573
	tp->write_seq += tp->max_window + 2;
	if (tp->write_seq == 0)
L
Linus Torvalds 已提交
2574
		tp->write_seq = 1;
2575
	icsk->icsk_backoff = 0;
L
Linus Torvalds 已提交
2576
	tp->snd_cwnd = 2;
2577
	icsk->icsk_probes_out = 0;
I
Ilpo Järvinen 已提交
2578
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
L
Linus Torvalds 已提交
2579
	tp->snd_cwnd_cnt = 0;
2580
	tp->window_clamp = 0;
2581
	tp->delivered_ce = 0;
2582
	tcp_set_ca_state(sk, TCP_CA_Open);
2583
	tp->is_sack_reneg = 0;
L
Linus Torvalds 已提交
2584
	tcp_clear_retrans(tp);
2585
	inet_csk_delack_init(sk);
2586 2587 2588 2589
	/* 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;
2590
	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
L
Linus Torvalds 已提交
2591
	__sk_dst_reset(sk);
2592 2593
	dst_release(sk->sk_rx_dst);
	sk->sk_rx_dst = NULL;
2594
	tcp_saved_syn_free(tp);
E
Eric Dumazet 已提交
2595
	tp->compressed_ack = 0;
W
Wei Wang 已提交
2596
	tp->bytes_sent = 0;
2597
	tp->bytes_retrans = 0;
W
Wei Wang 已提交
2598
	tp->dsack_dups = 0;
2599
	tp->reord_seen = 0;
L
Linus Torvalds 已提交
2600

2601 2602 2603 2604
	/* Clean up fastopen related fields */
	tcp_free_fastopen_req(tp);
	inet->defer_connect = 0;

E
Eric Dumazet 已提交
2605
	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
L
Linus Torvalds 已提交
2606

2607 2608 2609 2610 2611 2612
	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
2613
	sk->sk_error_report(sk);
Y
YueHaibing 已提交
2614
	return 0;
L
Linus Torvalds 已提交
2615
}
E
Eric Dumazet 已提交
2616
EXPORT_SYMBOL(tcp_disconnect);
L
Linus Torvalds 已提交
2617

E
Eric Dumazet 已提交
2618
static inline bool tcp_can_repair_sock(const struct sock *sk)
P
Pavel Emelyanov 已提交
2619
{
2620
	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2621
		(sk->sk_state != TCP_LISTEN);
P
Pavel Emelyanov 已提交
2622 2623
}

2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655
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;
}

2656
static int tcp_repair_options_est(struct sock *sk,
2657
		struct tcp_repair_opt __user *optbuf, unsigned int len)
2658
{
2659
	struct tcp_sock *tp = tcp_sk(sk);
2660
	struct tcp_repair_opt opt;
2661

2662 2663
	while (len >= sizeof(opt)) {
		if (copy_from_user(&opt, optbuf, sizeof(opt)))
2664 2665 2666
			return -EFAULT;

		optbuf++;
2667
		len -= sizeof(opt);
2668

2669 2670 2671
		switch (opt.opt_code) {
		case TCPOPT_MSS:
			tp->rx_opt.mss_clamp = opt.opt_val;
2672
			tcp_mtup_init(sk);
2673
			break;
2674
		case TCPOPT_WINDOW:
2675 2676 2677 2678
			{
				u16 snd_wscale = opt.opt_val & 0xFFFF;
				u16 rcv_wscale = opt.opt_val >> 16;

2679
				if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2680
					return -EFBIG;
2681

2682 2683 2684 2685
				tp->rx_opt.snd_wscale = snd_wscale;
				tp->rx_opt.rcv_wscale = rcv_wscale;
				tp->rx_opt.wscale_ok = 1;
			}
2686 2687
			break;
		case TCPOPT_SACK_PERM:
2688 2689 2690
			if (opt.opt_val != 0)
				return -EINVAL;

2691 2692 2693
			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
			break;
		case TCPOPT_TIMESTAMP:
2694 2695 2696
			if (opt.opt_val != 0)
				return -EINVAL;

2697 2698 2699 2700 2701 2702 2703 2704
			tp->rx_opt.tstamp_ok = 1;
			break;
		}
	}

	return 0;
}

L
Linus Torvalds 已提交
2705 2706 2707
/*
 *	Socket option code for TCP.
 */
2708
static int do_tcp_setsockopt(struct sock *sk, int level,
2709
		int optname, char __user *optval, unsigned int optlen)
L
Linus Torvalds 已提交
2710 2711
{
	struct tcp_sock *tp = tcp_sk(sk);
2712
	struct inet_connection_sock *icsk = inet_csk(sk);
2713
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2714 2715 2716
	int val;
	int err = 0;

2717 2718 2719
	/* These are data/string values, all the others are ints */
	switch (optname) {
	case TCP_CONGESTION: {
2720 2721 2722 2723 2724 2725
		char name[TCP_CA_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
2726
					min_t(long, TCP_CA_NAME_MAX-1, optlen));
2727 2728 2729 2730 2731
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
2732
		err = tcp_set_congestion_control(sk, name, true, true);
2733 2734 2735
		release_sock(sk);
		return err;
	}
D
Dave Watson 已提交
2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753
	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;
	}
2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764
	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));
	}
2765 2766 2767
	default:
		/* fallthru */
		break;
2768
	}
2769

L
Linus Torvalds 已提交
2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781
	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
2782 2783
		 * know which interface is going to be used
		 */
2784
		if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
L
Linus Torvalds 已提交
2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801
			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;
2802
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2803 2804 2805 2806 2807
		} else {
			tp->nonagle &= ~TCP_NAGLE_OFF;
		}
		break;

A
Andreas Petlund 已提交
2808 2809 2810 2811 2812 2813 2814
	case TCP_THIN_LINEAR_TIMEOUTS:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->thin_lto = val;
		break;

A
Andreas Petlund 已提交
2815 2816 2817 2818 2819
	case TCP_THIN_DUPACK:
		if (val < 0 || val > 1)
			err = -EINVAL;
		break;

P
Pavel Emelyanov 已提交
2820 2821 2822
	case TCP_REPAIR:
		if (!tcp_can_repair_sock(sk))
			err = -EPERM;
2823
		else if (val == TCP_REPAIR_ON) {
P
Pavel Emelyanov 已提交
2824 2825 2826
			tp->repair = 1;
			sk->sk_reuse = SK_FORCE_REUSE;
			tp->repair_queue = TCP_NO_QUEUE;
2827
		} else if (val == TCP_REPAIR_OFF) {
P
Pavel Emelyanov 已提交
2828 2829 2830
			tp->repair = 0;
			sk->sk_reuse = SK_NO_REUSE;
			tcp_send_window_probe(sk);
2831
		} else if (val == TCP_REPAIR_OFF_NO_WP) {
P
Pavel Emelyanov 已提交
2832 2833 2834 2835 2836 2837 2838 2839 2840 2841
			tp->repair = 0;
			sk->sk_reuse = SK_NO_REUSE;
		} else
			err = -EINVAL;

		break;

	case TCP_REPAIR_QUEUE:
		if (!tp->repair)
			err = -EPERM;
2842
		else if ((unsigned int)val < TCP_QUEUES_NR)
P
Pavel Emelyanov 已提交
2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858
			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;

2859 2860 2861 2862
	case TCP_REPAIR_OPTIONS:
		if (!tp->repair)
			err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
2863
			err = tcp_repair_options_est(sk,
2864 2865
					(struct tcp_repair_opt __user *)optval,
					optlen);
2866 2867 2868 2869
		else
			err = -EPERM;
		break;

L
Linus Torvalds 已提交
2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887
	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;
2888
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899
		}
		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))) {
2900
				u32 elapsed = keepalive_time_elapsed(tp);
L
Linus Torvalds 已提交
2901 2902 2903 2904
				if (tp->keepalive_time > elapsed)
					elapsed = tp->keepalive_time - elapsed;
				else
					elapsed = 0;
2905
				inet_csk_reset_keepalive_timer(sk, elapsed);
L
Linus Torvalds 已提交
2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924
			}
		}
		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
2925
			icsk->icsk_syn_retries = val;
L
Linus Torvalds 已提交
2926 2927
		break;

2928 2929 2930 2931 2932 2933 2934
	case TCP_SAVE_SYN:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->save_syn = val;
		break;

L
Linus Torvalds 已提交
2935 2936 2937
	case TCP_LINGER2:
		if (val < 0)
			tp->linger2 = -1;
2938
		else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
L
Linus Torvalds 已提交
2939 2940 2941 2942 2943 2944
			tp->linger2 = 0;
		else
			tp->linger2 = val * HZ;
		break;

	case TCP_DEFER_ACCEPT:
2945 2946 2947 2948
		/* 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
2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964
		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) {
2965
			icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2966
		} else {
2967
			icsk->icsk_ack.pingpong = 0;
L
Linus Torvalds 已提交
2968 2969
			if ((1 << sk->sk_state) &
			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2970 2971
			    inet_csk_ack_scheduled(sk)) {
				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2972
				tcp_cleanup_rbuf(sk, 1);
L
Linus Torvalds 已提交
2973
				if (!(val & 1))
2974
					icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2975 2976 2977 2978
			}
		}
		break;

2979 2980
#ifdef CONFIG_TCP_MD5SIG
	case TCP_MD5SIG:
2981
	case TCP_MD5SIG_EXT:
2982 2983 2984 2985
		if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))
			err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
		else
			err = -EINVAL;
2986 2987
		break;
#endif
2988
	case TCP_USER_TIMEOUT:
2989
		/* Cap the max time in ms TCP will retry or probe the window
2990 2991
		 * before giving up and aborting (ETIMEDOUT) a connection.
		 */
2992 2993 2994
		if (val < 0)
			err = -EINVAL;
		else
2995
			icsk->icsk_user_timeout = val;
2996
		break;
2997 2998 2999

	case TCP_FASTOPEN:
		if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
3000
		    TCPF_LISTEN))) {
3001
			tcp_fastopen_init_key_once(net);
3002

3003
			fastopen_queue_tune(sk, val);
3004
		} else {
3005
			err = -EINVAL;
3006
		}
3007
		break;
W
Wei Wang 已提交
3008 3009 3010
	case TCP_FASTOPEN_CONNECT:
		if (val > 1 || val < 0) {
			err = -EINVAL;
3011
		} else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
W
Wei Wang 已提交
3012 3013 3014 3015 3016 3017 3018 3019
			if (sk->sk_state == TCP_CLOSE)
				tp->fastopen_connect = val;
			else
				err = -EINVAL;
		} else {
			err = -EOPNOTSUPP;
		}
		break;
3020 3021 3022 3023 3024 3025 3026 3027
	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;
3028 3029 3030 3031
	case TCP_TIMESTAMP:
		if (!tp->repair)
			err = -EPERM;
		else
3032
			tp->tsoffset = val - tcp_time_stamp_raw();
3033
		break;
3034 3035 3036
	case TCP_REPAIR_WINDOW:
		err = tcp_repair_set_window(tp, optval, optlen);
		break;
3037 3038 3039 3040
	case TCP_NOTSENT_LOWAT:
		tp->notsent_lowat = val;
		sk->sk_write_space(sk);
		break;
3041 3042 3043 3044 3045 3046
	case TCP_INQ:
		if (val > 1 || val < 0)
			err = -EINVAL;
		else
			tp->recvmsg_inq = val;
		break;
L
Linus Torvalds 已提交
3047 3048 3049
	default:
		err = -ENOPROTOOPT;
		break;
3050 3051
	}

L
Linus Torvalds 已提交
3052 3053 3054 3055
	release_sock(sk);
	return err;
}

3056
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
3057
		   unsigned int optlen)
3058
{
3059
	const struct inet_connection_sock *icsk = inet_csk(sk);
3060 3061 3062 3063 3064 3065

	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
3066
EXPORT_SYMBOL(tcp_setsockopt);
3067 3068

#ifdef CONFIG_COMPAT
3069
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
3070
			  char __user *optval, unsigned int optlen)
3071
{
3072 3073 3074
	if (level != SOL_TCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
3075 3076
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
3077
EXPORT_SYMBOL(compat_tcp_setsockopt);
3078 3079
#endif

3080 3081 3082 3083 3084 3085 3086 3087 3088
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)
3089
			stats[i] += tcp_jiffies32 - tp->chrono_start;
3090 3091 3092 3093 3094 3095 3096 3097 3098
		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
3099
/* Return information about state of tcp endpoint in API format. */
3100
void tcp_get_info(struct sock *sk, struct tcp_info *info)
L
Linus Torvalds 已提交
3101
{
3102
	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
3103
	const struct inet_connection_sock *icsk = inet_csk(sk);
3104
	u32 now;
3105
	u64 rate64;
3106
	bool slow;
3107
	u32 rate;
L
Linus Torvalds 已提交
3108 3109

	memset(info, 0, sizeof(*info));
3110 3111
	if (sk->sk_type != SOCK_STREAM)
		return;
L
Linus Torvalds 已提交
3112

3113
	info->tcpi_state = inet_sk_state_load(sk);
3114

3115 3116 3117
	/* Report meaningful fields for all TCP states, including listeners */
	rate = READ_ONCE(sk->sk_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
3118
	info->tcpi_pacing_rate = rate64;
3119 3120 3121

	rate = READ_ONCE(sk->sk_max_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
3122
	info->tcpi_max_pacing_rate = rate64;
3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135

	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;
	}
3136 3137 3138

	slow = lock_sock_fast(sk);

3139
	info->tcpi_ca_state = icsk->icsk_ca_state;
3140
	info->tcpi_retransmits = icsk->icsk_retransmits;
3141
	info->tcpi_probes = icsk->icsk_probes_out;
3142
	info->tcpi_backoff = icsk->icsk_backoff;
L
Linus Torvalds 已提交
3143 3144 3145

	if (tp->rx_opt.tstamp_ok)
		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
3146
	if (tcp_is_sack(tp))
L
Linus Torvalds 已提交
3147 3148 3149 3150 3151
		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;
3152
	}
L
Linus Torvalds 已提交
3153

E
Eric Dumazet 已提交
3154
	if (tp->ecn_flags & TCP_ECN_OK)
L
Linus Torvalds 已提交
3155
		info->tcpi_options |= TCPI_OPT_ECN;
E
Eric Dumazet 已提交
3156 3157
	if (tp->ecn_flags & TCP_ECN_SEEN)
		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Y
Yuchung Cheng 已提交
3158 3159
	if (tp->syn_data_acked)
		info->tcpi_options |= TCPI_OPT_SYN_DATA;
L
Linus Torvalds 已提交
3160

3161 3162
	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
3163
	info->tcpi_snd_mss = tp->mss_cache;
3164
	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
L
Linus Torvalds 已提交
3165

3166 3167 3168
	info->tcpi_unacked = tp->packets_out;
	info->tcpi_sacked = tp->sacked_out;

L
Linus Torvalds 已提交
3169 3170 3171
	info->tcpi_lost = tp->lost_out;
	info->tcpi_retrans = tp->retrans_out;

3172
	now = tcp_jiffies32;
L
Linus Torvalds 已提交
3173
	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
3174
	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
L
Linus Torvalds 已提交
3175 3176
	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);

3177
	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
L
Linus Torvalds 已提交
3178
	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
3179 3180
	info->tcpi_rtt = tp->srtt_us >> 3;
	info->tcpi_rttvar = tp->mdev_us >> 2;
L
Linus Torvalds 已提交
3181 3182 3183
	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
	info->tcpi_advmss = tp->advmss;

3184
	info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
L
Linus Torvalds 已提交
3185 3186 3187
	info->tcpi_rcv_space = tp->rcvq_space.space;

	info->tcpi_total_retrans = tp->total_retrans;
3188

3189 3190
	info->tcpi_bytes_acked = tp->bytes_acked;
	info->tcpi_bytes_received = tp->bytes_received;
3191
	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
3192
	tcp_get_info_chrono_stats(tp, info);
3193

3194 3195
	info->tcpi_segs_out = tp->segs_out;
	info->tcpi_segs_in = tp->segs_in;
3196 3197

	info->tcpi_min_rtt = tcp_min_rtt(tp);
3198 3199
	info->tcpi_data_segs_in = tp->data_segs_in;
	info->tcpi_data_segs_out = tp->data_segs_out;
Y
Yuchung Cheng 已提交
3200 3201

	info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
3202 3203
	rate64 = tcp_compute_delivery_rate(tp);
	if (rate64)
3204
		info->tcpi_delivery_rate = rate64;
3205 3206
	info->tcpi_delivered = tp->delivered;
	info->tcpi_delivered_ce = tp->delivered_ce;
W
Wei Wang 已提交
3207
	info->tcpi_bytes_sent = tp->bytes_sent;
3208
	info->tcpi_bytes_retrans = tp->bytes_retrans;
W
Wei Wang 已提交
3209
	info->tcpi_dsack_dups = tp->dsack_dups;
3210
	info->tcpi_reord_seen = tp->reord_seen;
3211
	unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
3212 3213 3214
}
EXPORT_SYMBOL_GPL(tcp_get_info);

3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234
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
3235
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_SENT */
3236
		nla_total_size_64bit(sizeof(u64)) + /* TCP_NLA_BYTES_RETRANS */
W
Wei Wang 已提交
3237
		nla_total_size(sizeof(u32)) + /* TCP_NLA_DSACK_DUPS */
3238
		nla_total_size(sizeof(u32)) + /* TCP_NLA_REORD_SEEN */
3239 3240 3241
		0;
}

3242 3243 3244 3245 3246
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;
3247 3248
	u64 rate64;
	u32 rate;
3249

3250
	stats = alloc_skb(tcp_opt_stats_get_size(), GFP_ATOMIC);
3251 3252 3253 3254 3255 3256 3257 3258 3259 3260
	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);
3261 3262 3263 3264
	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);
3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278

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

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

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

	nla_put_u8(stats, TCP_NLA_RECUR_RETRANS, inet_csk(sk)->icsk_retransmits);
	nla_put_u8(stats, TCP_NLA_DELIVERY_RATE_APP_LMT, !!tp->rate_app_limited);
3279
	nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, tp->snd_ssthresh);
3280 3281
	nla_put_u32(stats, TCP_NLA_DELIVERED, tp->delivered);
	nla_put_u32(stats, TCP_NLA_DELIVERED_CE, tp->delivered_ce);
3282 3283

	nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una);
3284
	nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state);
3285

W
Wei Wang 已提交
3286 3287
	nla_put_u64_64bit(stats, TCP_NLA_BYTES_SENT, tp->bytes_sent,
			  TCP_NLA_PAD);
3288 3289
	nla_put_u64_64bit(stats, TCP_NLA_BYTES_RETRANS, tp->bytes_retrans,
			  TCP_NLA_PAD);
W
Wei Wang 已提交
3290
	nla_put_u32(stats, TCP_NLA_DSACK_DUPS, tp->dsack_dups);
3291
	nla_put_u32(stats, TCP_NLA_REORD_SEEN, tp->reord_seen);
W
Wei Wang 已提交
3292

3293 3294 3295
	return stats;
}

3296 3297
static int do_tcp_getsockopt(struct sock *sk, int level,
		int optname, char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
3298
{
3299
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
3300
	struct tcp_sock *tp = tcp_sk(sk);
3301
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313
	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:
3314
		val = tp->mss_cache;
L
Linus Torvalds 已提交
3315 3316
		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			val = tp->rx_opt.user_mss;
3317 3318
		if (tp->repair)
			val = tp->rx_opt.mss_clamp;
L
Linus Torvalds 已提交
3319 3320 3321 3322 3323 3324 3325 3326
		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
3327
		val = keepalive_time_when(tp) / HZ;
L
Linus Torvalds 已提交
3328 3329
		break;
	case TCP_KEEPINTVL:
E
Eric Dumazet 已提交
3330
		val = keepalive_intvl_when(tp) / HZ;
L
Linus Torvalds 已提交
3331 3332
		break;
	case TCP_KEEPCNT:
E
Eric Dumazet 已提交
3333
		val = keepalive_probes(tp);
L
Linus Torvalds 已提交
3334 3335
		break;
	case TCP_SYNCNT:
3336
		val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
L
Linus Torvalds 已提交
3337 3338 3339 3340
		break;
	case TCP_LINGER2:
		val = tp->linger2;
		if (val >= 0)
3341
			val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
L
Linus Torvalds 已提交
3342 3343
		break;
	case TCP_DEFER_ACCEPT:
3344 3345
		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
3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364
		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;
	}
3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384
	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
3385
	case TCP_QUICKACK:
3386
		val = !icsk->icsk_ack.pingpong;
L
Linus Torvalds 已提交
3387
		break;
3388 3389 3390 3391 3392 3393 3394

	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;
3395
		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
3396 3397
			return -EFAULT;
		return 0;
3398

D
Dave Watson 已提交
3399 3400 3401 3402
	case TCP_ULP:
		if (get_user(len, optlen))
			return -EFAULT;
		len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
3403 3404 3405 3406 3407
		if (!icsk->icsk_ulp_ops) {
			if (put_user(0, optlen))
				return -EFAULT;
			return 0;
		}
D
Dave Watson 已提交
3408 3409 3410 3411 3412 3413
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len))
			return -EFAULT;
		return 0;

3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435
	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;
	}
3436 3437 3438
	case TCP_THIN_LINEAR_TIMEOUTS:
		val = tp->thin_lto;
		break;
Y
Yuchung Cheng 已提交
3439

3440
	case TCP_THIN_DUPACK:
Y
Yuchung Cheng 已提交
3441
		val = 0;
3442
		break;
3443

P
Pavel Emelyanov 已提交
3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454
	case TCP_REPAIR:
		val = tp->repair;
		break;

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

3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476
	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
3477 3478 3479 3480 3481 3482 3483 3484 3485
	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;

3486
	case TCP_USER_TIMEOUT:
3487
		val = icsk->icsk_user_timeout;
3488
		break;
3489 3490

	case TCP_FASTOPEN:
3491
		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3492 3493
		break;

W
Wei Wang 已提交
3494 3495 3496 3497
	case TCP_FASTOPEN_CONNECT:
		val = tp->fastopen_connect;
		break;

3498 3499 3500 3501
	case TCP_FASTOPEN_NO_COOKIE:
		val = tp->fastopen_no_cookie;
		break;

3502
	case TCP_TIMESTAMP:
3503
		val = tcp_time_stamp_raw() + tp->tsoffset;
3504
		break;
3505 3506 3507
	case TCP_NOTSENT_LOWAT:
		val = tp->notsent_lowat;
		break;
3508 3509 3510
	case TCP_INQ:
		val = tp->recvmsg_inq;
		break;
3511 3512 3513 3514 3515 3516 3517 3518 3519
	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) {
3520 3521 3522 3523 3524 3525 3526 3527 3528
			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];
3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546
			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;
	}
3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565
#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
3566 3567
	default:
		return -ENOPROTOOPT;
3568
	}
L
Linus Torvalds 已提交
3569 3570 3571 3572 3573 3574 3575 3576

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

3577 3578 3579 3580 3581 3582 3583 3584 3585 3586
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
3587
EXPORT_SYMBOL(tcp_getsockopt);
3588 3589

#ifdef CONFIG_COMPAT
3590 3591
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
			  char __user *optval, int __user *optlen)
3592
{
3593 3594 3595
	if (level != SOL_TCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
3596 3597
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
3598
EXPORT_SYMBOL(compat_tcp_getsockopt);
3599
#endif
L
Linus Torvalds 已提交
3600

3601
#ifdef CONFIG_TCP_MD5SIG
E
Eric Dumazet 已提交
3602
static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3603
static DEFINE_MUTEX(tcp_md5sig_mutex);
E
Eric Dumazet 已提交
3604
static bool tcp_md5sig_pool_populated = false;
3605

3606
static void __tcp_alloc_md5sig_pool(void)
3607
{
H
Herbert Xu 已提交
3608
	struct crypto_ahash *hash;
3609 3610
	int cpu;

H
Herbert Xu 已提交
3611
	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3612
	if (IS_ERR(hash))
H
Herbert Xu 已提交
3613 3614
		return;

3615
	for_each_possible_cpu(cpu) {
3616
		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
H
Herbert Xu 已提交
3617
		struct ahash_request *req;
3618

3619 3620 3621 3622 3623 3624 3625 3626 3627
		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
3628 3629 3630 3631 3632 3633 3634 3635 3636 3637
		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;
3638
	}
E
Eric Dumazet 已提交
3639 3640
	/* before setting tcp_md5sig_pool_populated, we must commit all writes
	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3641 3642
	 */
	smp_wmb();
E
Eric Dumazet 已提交
3643
	tcp_md5sig_pool_populated = true;
3644 3645
}

3646
bool tcp_alloc_md5sig_pool(void)
3647
{
E
Eric Dumazet 已提交
3648
	if (unlikely(!tcp_md5sig_pool_populated)) {
3649 3650
		mutex_lock(&tcp_md5sig_mutex);

E
Eric Dumazet 已提交
3651
		if (!tcp_md5sig_pool_populated)
3652 3653 3654
			__tcp_alloc_md5sig_pool();

		mutex_unlock(&tcp_md5sig_mutex);
3655
	}
E
Eric Dumazet 已提交
3656
	return tcp_md5sig_pool_populated;
3657 3658 3659
}
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);

E
Eric Dumazet 已提交
3660 3661 3662 3663 3664 3665 3666 3667 3668

/**
 *	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)
3669
{
E
Eric Dumazet 已提交
3670
	local_bh_disable();
3671

E
Eric Dumazet 已提交
3672 3673 3674 3675 3676
	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
3677 3678 3679 3680
	local_bh_enable();
	return NULL;
}
EXPORT_SYMBOL(tcp_get_md5sig_pool);
3681

3682
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3683
			  const struct sk_buff *skb, unsigned int header_len)
3684 3685 3686
{
	struct scatterlist sg;
	const struct tcphdr *tp = tcp_hdr(skb);
H
Herbert Xu 已提交
3687
	struct ahash_request *req = hp->md5_req;
3688 3689 3690
	unsigned int i;
	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
					   skb_headlen(skb) - header_len : 0;
3691
	const struct skb_shared_info *shi = skb_shinfo(skb);
3692
	struct sk_buff *frag_iter;
3693 3694 3695 3696

	sg_init_table(&sg, 1);

	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
H
Herbert Xu 已提交
3697 3698
	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
	if (crypto_ahash_update(req))
3699 3700 3701 3702
		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
3703 3704 3705 3706 3707
		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
3708 3709
		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
		if (crypto_ahash_update(req))
3710 3711 3712
			return 1;
	}

3713 3714 3715 3716
	skb_walk_frags(skb, frag_iter)
		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
			return 1;

3717 3718 3719 3720
	return 0;
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

3721
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3722 3723 3724 3725
{
	struct scatterlist sg;

	sg_init_one(&sg, key->key, key->keylen);
H
Herbert Xu 已提交
3726 3727
	ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
	return crypto_ahash_update(hp->md5_req);
3728 3729 3730
}
EXPORT_SYMBOL(tcp_md5_hash_key);

3731 3732
#endif

A
Andi Kleen 已提交
3733 3734
void tcp_done(struct sock *sk)
{
3735 3736
	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;

3737
	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3738
		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
A
Andi Kleen 已提交
3739 3740 3741

	tcp_set_state(sk, TCP_CLOSE);
	tcp_clear_xmit_timers(sk);
3742
	if (req)
3743
		reqsk_fastopen_remove(sk, req, false);
A
Andi Kleen 已提交
3744 3745 3746 3747 3748 3749 3750 3751 3752 3753

	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);

3754 3755 3756
int tcp_abort(struct sock *sk, int err)
{
	if (!sk_fullsock(sk)) {
3757 3758 3759 3760
		if (sk->sk_state == TCP_NEW_SYN_RECV) {
			struct request_sock *req = inet_reqsk(sk);

			local_bh_disable();
3761
			inet_csk_reqsk_queue_drop(req->rsk_listener, req);
3762 3763 3764
			local_bh_enable();
			return 0;
		}
3765 3766 3767 3768 3769 3770
		return -EOPNOTSUPP;
	}

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

3771 3772 3773 3774 3775
	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);
		inet_csk_listen_stop(sk);
	}

3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791
	/* 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();
3792
	tcp_write_queue_purge(sk);
3793 3794 3795 3796 3797
	release_sock(sk);
	return 0;
}
EXPORT_SYMBOL_GPL(tcp_abort);

3798
extern struct tcp_congestion_ops tcp_reno;
L
Linus Torvalds 已提交
3799 3800 3801 3802

static __initdata unsigned long thash_entries;
static int __init set_thash_entries(char *str)
{
3803 3804
	ssize_t ret;

L
Linus Torvalds 已提交
3805 3806
	if (!str)
		return 0;
3807 3808 3809 3810 3811

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

L
Linus Torvalds 已提交
3812 3813 3814 3815
	return 1;
}
__setup("thash_entries=", set_thash_entries);

F
Fabian Frederick 已提交
3816
static void __init tcp_init_mem(void)
3817
{
E
Eric Dumazet 已提交
3818 3819
	unsigned long limit = nr_free_buffer_pages() / 16;

3820
	limit = max(limit, 128UL);
E
Eric Dumazet 已提交
3821 3822 3823
	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 % */
3824 3825
}

L
Linus Torvalds 已提交
3826 3827
void __init tcp_init(void)
{
3828
	int max_rshare, max_wshare, cnt;
3829
	unsigned long limit;
3830
	unsigned int i;
L
Linus Torvalds 已提交
3831

3832 3833
	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
L
Linus Torvalds 已提交
3834

3835 3836
	percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
	percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3837
	inet_hashinfo_init(&tcp_hashinfo);
3838 3839 3840
	inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash",
			    thash_entries, 21,  /* one slot per 2 MB*/
			    0, 64 * 1024);
3841 3842 3843
	tcp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("tcp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
3844
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
3845 3846 3847 3848 3849 3850

	/* Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
3851
	tcp_hashinfo.ehash =
L
Linus Torvalds 已提交
3852
		alloc_large_system_hash("TCP established",
3853
					sizeof(struct inet_ehash_bucket),
L
Linus Torvalds 已提交
3854
					thash_entries,
E
Eric Dumazet 已提交
3855
					17, /* one slot per 128 KB of memory */
3856
					0,
L
Linus Torvalds 已提交
3857
					NULL,
3858
					&tcp_hashinfo.ehash_mask,
3859
					0,
3860
					thash_entries ? 0 : 512 * 1024);
E
Eric Dumazet 已提交
3861
	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3862
		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
E
Eric Dumazet 已提交
3863

3864 3865
	if (inet_ehash_locks_alloc(&tcp_hashinfo))
		panic("TCP: failed to alloc ehash_locks");
3866
	tcp_hashinfo.bhash =
L
Linus Torvalds 已提交
3867
		alloc_large_system_hash("TCP bind",
3868
					sizeof(struct inet_bind_hashbucket),
3869
					tcp_hashinfo.ehash_mask + 1,
E
Eric Dumazet 已提交
3870
					17, /* one slot per 128 KB of memory */
3871
					0,
3872
					&tcp_hashinfo.bhash_size,
L
Linus Torvalds 已提交
3873
					NULL,
3874
					0,
L
Linus Torvalds 已提交
3875
					64 * 1024);
3876
	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3877 3878 3879
	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
3880 3881
	}

E
Eric Dumazet 已提交
3882 3883 3884

	cnt = tcp_hashinfo.ehash_mask + 1;
	sysctl_tcp_max_orphans = cnt / 2;
L
Linus Torvalds 已提交
3885

3886
	tcp_init_mem();
3887
	/* Set per-socket limits to no more than 1/128 the pressure threshold */
E
Eric Dumazet 已提交
3888
	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3889 3890
	max_wshare = min(4UL*1024*1024, limit);
	max_rshare = min(6UL*1024*1024, limit);
3891

3892 3893 3894
	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);
3895

3896 3897 3898
	init_net.ipv4.sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
	init_net.ipv4.sysctl_tcp_rmem[1] = 87380;
	init_net.ipv4.sysctl_tcp_rmem[2] = max(87380, max_rshare);
L
Linus Torvalds 已提交
3899

3900
	pr_info("Hash tables configured (established %u bind %u)\n",
J
Joe Perches 已提交
3901
		tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3902

3903
	tcp_v4_init();
3904
	tcp_metrics_init();
3905
	BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
E
Eric Dumazet 已提交
3906
	tcp_tasklet_init();
L
Linus Torvalds 已提交
3907
}