tcp.c 94.5 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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/*
 *	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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__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, sk_sleep(sk), 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
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	 * by poll logic and correct handling of state changes
	 * made by other threads is impossible in any case.
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	 */

	mask = 0;

	/*
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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()
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	 * in state CLOSE_WAIT. One solution is evident --- to set EPOLLHUP
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	 * if and only if shutdown has been made in both directions.
	 * Actually, it is interesting to look how Solaris and DUX
534
	 * solve this dilemma. I would prefer, if EPOLLHUP were maskable,
L
Linus Torvalds 已提交
535 536
	 * then we could set it on SND_SHUTDOWN. BTW examples given
	 * in Stevens' books assume exactly this behaviour, it explains
537
	 * why EPOLLHUP is incompatible with EPOLLOUT.	--ANK
L
Linus Torvalds 已提交
538 539 540 541
	 *
	 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
	 * blocking on fresh not-connected or disconnected socket. --ANK
	 */
542
	if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
543
		mask |= EPOLLHUP;
L
Linus Torvalds 已提交
544
	if (sk->sk_shutdown & RCV_SHUTDOWN)
545
		mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
L
Linus Torvalds 已提交
546

547
	/* Connected or passive Fast Open socket? */
548 549
	if (state != TCP_SYN_SENT &&
	    (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
550 551 552 553 554
		int target = sock_rcvlowat(sk, 0, INT_MAX);

		if (tp->urg_seq == tp->copied_seq &&
		    !sock_flag(sk, SOCK_URGINLINE) &&
		    tp->urg_data)
555
			target++;
556 557

		if (tp->rcv_nxt - tp->copied_seq >= target)
558
			mask |= EPOLLIN | EPOLLRDNORM;
L
Linus Torvalds 已提交
559 560

		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
561
			if (sk_stream_is_writeable(sk)) {
562
				mask |= EPOLLOUT | EPOLLWRNORM;
L
Linus Torvalds 已提交
563
			} else {  /* send SIGIO later */
564
				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
565 566 567 568
				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);

				/* Race breaker. If space is freed after
				 * wspace test but before the flags are set,
569 570
				 * IO signal will be lost. Memory barrier
				 * pairs with the input side.
L
Linus Torvalds 已提交
571
				 */
572
				smp_mb__after_atomic();
573
				if (sk_stream_is_writeable(sk))
574
					mask |= EPOLLOUT | EPOLLWRNORM;
L
Linus Torvalds 已提交
575
			}
576
		} else
577
			mask |= EPOLLOUT | EPOLLWRNORM;
L
Linus Torvalds 已提交
578 579

		if (tp->urg_data & TCP_URG_VALID)
580
			mask |= EPOLLPRI;
581
	} else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
W
Wei Wang 已提交
582
		/* Active TCP fastopen socket with defer_connect
583
		 * Return EPOLLOUT so application can call write()
W
Wei Wang 已提交
584 585
		 * in order for kernel to generate SYN+data
		 */
586
		mask |= EPOLLOUT | EPOLLWRNORM;
L
Linus Torvalds 已提交
587
	}
T
Tom Marshall 已提交
588 589
	/* This barrier is coupled with smp_wmb() in tcp_reset() */
	smp_rmb();
590
	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
591
		mask |= EPOLLERR;
T
Tom Marshall 已提交
592

L
Linus Torvalds 已提交
593 594
	return mask;
}
E
Eric Dumazet 已提交
595
EXPORT_SYMBOL(tcp_poll);
L
Linus Torvalds 已提交
596 597 598 599 600

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
601
	bool slow;
L
Linus Torvalds 已提交
602 603 604 605 606 607

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

E
Eric Dumazet 已提交
608
		slow = lock_sock_fast(sk);
609
		answ = tcp_inq(sk);
E
Eric Dumazet 已提交
610
		unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
611 612 613 614 615 616 617 618 619 620 621 622 623
		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;
624 625 626 627 628 629 630 631 632
	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
633 634
	default:
		return -ENOIOCTLCMD;
635
	}
L
Linus Torvalds 已提交
636 637 638

	return put_user(answ, (int __user *)arg);
}
E
Eric Dumazet 已提交
639
EXPORT_SYMBOL(tcp_ioctl);
L
Linus Torvalds 已提交
640 641 642

static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
{
E
Eric Dumazet 已提交
643
	TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
L
Linus Torvalds 已提交
644 645 646
	tp->pushed_seq = tp->write_seq;
}

E
Eric Dumazet 已提交
647
static inline bool forced_push(const struct tcp_sock *tp)
L
Linus Torvalds 已提交
648 649 650 651
{
	return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
}

652
static void skb_entail(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
653
{
654
	struct tcp_sock *tp = tcp_sk(sk);
655 656 657 658
	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
659
	tcb->tcp_flags = TCPHDR_ACK;
660
	tcb->sacked  = 0;
661
	__skb_header_release(skb);
662
	tcp_add_write_queue_tail(sk, skb);
663 664
	sk->sk_wmem_queued += skb->truesize;
	sk_mem_charge(sk, skb->truesize);
665
	if (tp->nonagle & TCP_NAGLE_PUSH)
666
		tp->nonagle &= ~TCP_NAGLE_PUSH;
667 668

	tcp_slow_start_after_idle_check(sk);
L
Linus Torvalds 已提交
669 670
}

671
static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
L
Linus Torvalds 已提交
672
{
I
Ilpo Järvinen 已提交
673
	if (flags & MSG_OOB)
L
Linus Torvalds 已提交
674 675 676
		tp->snd_up = tp->write_seq;
}

E
Eric Dumazet 已提交
677
/* If a not yet filled skb is pushed, do not send it if
678
 * we have data packets in Qdisc or NIC queues :
E
Eric Dumazet 已提交
679 680 681 682
 * 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
683 684 685
 * 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
686 687 688
 */
static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
				int size_goal)
L
Linus Torvalds 已提交
689
{
E
Eric Dumazet 已提交
690
	return skb->len < size_goal &&
691
	       sock_net(sk)->ipv4.sysctl_tcp_autocorking &&
692
	       skb != tcp_write_queue_head(sk) &&
693
	       refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
E
Eric Dumazet 已提交
694 695 696 697 698 699 700
}

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;
701

E
Eric Dumazet 已提交
702
	skb = tcp_write_queue_tail(sk);
703 704
	if (!skb)
		return;
E
Eric Dumazet 已提交
705 706 707 708 709 710 711 712
	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 */
713
		if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
E
Eric Dumazet 已提交
714
			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
715
			set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
E
Eric Dumazet 已提交
716
		}
717 718 719
		/* It is possible TX completion already happened
		 * before we set TSQ_THROTTLED.
		 */
720
		if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
721
			return;
L
Linus Torvalds 已提交
722
	}
E
Eric Dumazet 已提交
723 724 725 726 727

	if (flags & MSG_MORE)
		nonagle = TCP_NAGLE_CORK;

	__tcp_push_pending_frames(sk, mss_now, nonagle);
L
Linus Torvalds 已提交
728 729
}

730 731
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
732 733
{
	struct tcp_splice_state *tss = rd_desc->arg.data;
734
	int ret;
J
Jens Axboe 已提交
735

736
	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
A
Al Viro 已提交
737
			      min(rd_desc->count, len), tss->flags);
738 739 740
	if (ret > 0)
		rd_desc->count -= ret;
	return ret;
J
Jens Axboe 已提交
741 742 743 744 745 746 747
}

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,
748
		.count	  = tss->len,
J
Jens Axboe 已提交
749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779
	};

	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;

780
	sock_rps_record_flow(sk);
J
Jens Axboe 已提交
781 782 783 784 785 786 787 788 789 790
	/*
	 * We can't seek on a socket input
	 */
	if (unlikely(*ppos))
		return -ESPIPE;

	ret = spliced = 0;

	lock_sock(sk);

791
	timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
J
Jens Axboe 已提交
792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819
	while (tss.len) {
		ret = __tcp_splice_read(sk, &tss);
		if (ret < 0)
			break;
		else if (!ret) {
			if (spliced)
				break;
			if (sock_flag(sk, SOCK_DONE))
				break;
			if (sk->sk_err) {
				ret = sock_error(sk);
				break;
			}
			if (sk->sk_shutdown & RCV_SHUTDOWN)
				break;
			if (sk->sk_state == TCP_CLOSE) {
				/*
				 * This occurs when user tries to read
				 * from never connected socket.
				 */
				if (!sock_flag(sk, SOCK_DONE))
					ret = -ENOTCONN;
				break;
			}
			if (!timeo) {
				ret = -EAGAIN;
				break;
			}
820 821 822 823 824 825
			/* 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;
826
			sk_wait_data(sk, &timeo, NULL);
J
Jens Axboe 已提交
827 828 829 830 831 832 833 834 835
			if (signal_pending(current)) {
				ret = sock_intr_errno(timeo);
				break;
			}
			continue;
		}
		tss.len -= ret;
		spliced += ret;

836 837
		if (!timeo)
			break;
J
Jens Axboe 已提交
838 839 840 841
		release_sock(sk);
		lock_sock(sk);

		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
842
		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
J
Jens Axboe 已提交
843 844 845 846 847 848 849 850 851 852 853
		    signal_pending(current))
			break;
	}

	release_sock(sk);

	if (spliced)
		return spliced;

	return ret;
}
E
Eric Dumazet 已提交
854
EXPORT_SYMBOL(tcp_splice_read);
J
Jens Axboe 已提交
855

856 857
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
				    bool force_schedule)
858 859 860 861 862 863
{
	struct sk_buff *skb;

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

864 865 866
	if (unlikely(tcp_under_memory_pressure(sk)))
		sk_mem_reclaim_partial(sk);

867
	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
868
	if (likely(skb)) {
869
		bool mem_scheduled;
870

871 872
		if (force_schedule) {
			mem_scheduled = true;
873 874
			sk_forced_mem_schedule(sk, skb->truesize);
		} else {
875
			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
876
		}
877
		if (likely(mem_scheduled)) {
878
			skb_reserve(skb, sk->sk_prot->max_header);
879 880 881 882
			/*
			 * Make sure that we have exactly size bytes
			 * available to the caller, no more, no less.
			 */
E
Eric Dumazet 已提交
883
			skb->reserved_tailroom = skb->end - skb->tail - size;
884
			INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
885 886 887 888
			return skb;
		}
		__kfree_skb(skb);
	} else {
889
		sk->sk_prot->enter_memory_pressure(sk);
890 891 892 893 894
		sk_stream_moderate_sndbuf(sk);
	}
	return NULL;
}

I
Ilpo Järvinen 已提交
895 896 897 898
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
				       int large_allowed)
{
	struct tcp_sock *tp = tcp_sk(sk);
899
	u32 new_size_goal, size_goal;
E
Eric Dumazet 已提交
900

E
Eric Dumazet 已提交
901
	if (!large_allowed)
E
Eric Dumazet 已提交
902 903
		return mss_now;

904 905
	/* 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
906 907 908 909 910 911 912 913 914
	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
915 916
	}

E
Eric Dumazet 已提交
917
	return max(size_goal, mss_now);
I
Ilpo Järvinen 已提交
918 919 920 921 922 923 924 925 926 927 928 929
}

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;
}

930 931
ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
			 size_t size, int flags)
L
Linus Torvalds 已提交
932 933
{
	struct tcp_sock *tp = tcp_sk(sk);
934
	int mss_now, size_goal;
L
Linus Torvalds 已提交
935 936 937 938
	int err;
	ssize_t copied;
	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

939 940 941 942 943 944
	/* 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)) {
945 946
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
947
			goto out_err;
948
	}
L
Linus Torvalds 已提交
949

950
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
951

I
Ilpo Järvinen 已提交
952
	mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
953 954 955 956
	copied = 0;

	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
957
		goto out_err;
L
Linus Torvalds 已提交
958

959
	while (size > 0) {
960
		struct sk_buff *skb = tcp_write_queue_tail(sk);
961 962
		int copy, i;
		bool can_coalesce;
L
Linus Torvalds 已提交
963

964
		if (!skb || (copy = size_goal - skb->len) <= 0 ||
965
		    !tcp_skb_can_collapse_to(skb)) {
L
Linus Torvalds 已提交
966 967 968 969
new_segment:
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;

970
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
971
					tcp_rtx_and_write_queues_empty(sk));
L
Linus Torvalds 已提交
972 973 974
			if (!skb)
				goto wait_for_memory;

975
			skb_entail(sk, skb);
976
			copy = size_goal;
L
Linus Torvalds 已提交
977 978 979 980 981 982 983
		}

		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
984
		if (!can_coalesce && i >= sysctl_max_skb_frags) {
L
Linus Torvalds 已提交
985 986 987
			tcp_mark_push(tp, skb);
			goto new_segment;
		}
988
		if (!sk_wmem_schedule(sk, copy))
L
Linus Torvalds 已提交
989
			goto wait_for_memory;
990

L
Linus Torvalds 已提交
991
		if (can_coalesce) {
E
Eric Dumazet 已提交
992
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
L
Linus Torvalds 已提交
993 994 995 996
		} else {
			get_page(page);
			skb_fill_page_desc(skb, i, page, offset, copy);
		}
997
		skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
998

L
Linus Torvalds 已提交
999 1000 1001 1002
		skb->len += copy;
		skb->data_len += copy;
		skb->truesize += copy;
		sk->sk_wmem_queued += copy;
1003
		sk_mem_charge(sk, copy);
1004
		skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1005 1006
		tp->write_seq += copy;
		TCP_SKB_CB(skb)->end_seq += copy;
1007
		tcp_skb_pcount_set(skb, 0);
L
Linus Torvalds 已提交
1008 1009

		if (!copied)
E
Eric Dumazet 已提交
1010
			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
L
Linus Torvalds 已提交
1011 1012

		copied += copy;
1013
		offset += copy;
1014
		size -= copy;
1015
		if (!size)
L
Linus Torvalds 已提交
1016 1017
			goto out;

1018
		if (skb->len < size_goal || (flags & MSG_OOB))
L
Linus Torvalds 已提交
1019 1020 1021 1022
			continue;

		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
1023
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1024
		} else if (skb == tcp_send_head(sk))
L
Linus Torvalds 已提交
1025 1026 1027 1028 1029 1030
			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
1031 1032
		tcp_push(sk, flags & ~MSG_MORE, mss_now,
			 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1033

1034 1035
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
1036 1037
			goto do_error;

I
Ilpo Järvinen 已提交
1038
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1039 1040 1041
	}

out:
1042
	if (copied) {
E
Eric Dumazet 已提交
1043
		tcp_tx_timestamp(sk, sk->sk_tsflags);
1044 1045 1046
		if (!(flags & MSG_SENDPAGE_NOTLAST))
			tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
	}
L
Linus Torvalds 已提交
1047 1048 1049 1050 1051 1052
	return copied;

do_error:
	if (copied)
		goto out;
out_err:
1053
	/* make sure we wake any epoll edge trigger waiter */
1054 1055
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1056
		sk->sk_write_space(sk);
1057 1058
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1059 1060
	return sk_stream_error(sk, flags, err);
}
1061
EXPORT_SYMBOL_GPL(do_tcp_sendpages);
L
Linus Torvalds 已提交
1062

1063 1064
int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset,
			size_t size, int flags)
L
Linus Torvalds 已提交
1065
{
E
Eric Dumazet 已提交
1066
	if (!(sk->sk_route_caps & NETIF_F_SG))
1067
		return sock_no_sendpage_locked(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1068

1069 1070
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1071 1072
	return do_tcp_sendpages(sk, page, offset, size, flags);
}
1073
EXPORT_SYMBOL_GPL(tcp_sendpage_locked);
1074 1075 1076 1077 1078 1079 1080 1081

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
1082
	release_sock(sk);
1083 1084

	return ret;
L
Linus Torvalds 已提交
1085
}
E
Eric Dumazet 已提交
1086
EXPORT_SYMBOL(tcp_sendpage);
L
Linus Torvalds 已提交
1087

1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104
/* 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
1105
static int select_size(bool first_skb, bool zc)
L
Linus Torvalds 已提交
1106
{
E
Eric Dumazet 已提交
1107 1108 1109
	if (zc)
		return 0;
	return linear_payload_sz(first_skb);
L
Linus Torvalds 已提交
1110 1111
}

1112 1113
void tcp_free_fastopen_req(struct tcp_sock *tp)
{
1114
	if (tp->fastopen_req) {
1115 1116 1117 1118 1119
		kfree(tp->fastopen_req);
		tp->fastopen_req = NULL;
	}
}

1120 1121
static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
				int *copied, size_t size)
1122 1123
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Wei Wang 已提交
1124
	struct inet_sock *inet = inet_sk(sk);
1125
	struct sockaddr *uaddr = msg->msg_name;
1126 1127
	int err, flags;

1128
	if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
1129 1130
	    (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
	     uaddr->sa_family == AF_UNSPEC))
1131
		return -EOPNOTSUPP;
1132
	if (tp->fastopen_req)
1133 1134 1135 1136
		return -EALREADY; /* Another Fast Open is in progress */

	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
				   sk->sk_allocation);
1137
	if (unlikely(!tp->fastopen_req))
1138 1139
		return -ENOBUFS;
	tp->fastopen_req->data = msg;
1140
	tp->fastopen_req->size = size;
1141

W
Wei Wang 已提交
1142 1143 1144 1145 1146 1147 1148 1149 1150
	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;
		}
	}
1151
	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1152
	err = __inet_stream_connect(sk->sk_socket, uaddr,
1153
				    msg->msg_namelen, flags, 1);
1154 1155 1156 1157 1158 1159 1160 1161
	/* 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;
	}
1162 1163 1164
	return err;
}

1165
int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
L
Linus Torvalds 已提交
1166 1167
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Willem de Bruijn 已提交
1168
	struct ubuf_info *uarg = NULL;
L
Linus Torvalds 已提交
1169
	struct sk_buff *skb;
1170
	struct sockcm_cookie sockc;
1171 1172
	int flags, err, copied = 0;
	int mss_now = 0, size_goal, copied_syn = 0;
1173
	bool process_backlog = false;
E
Eric Dumazet 已提交
1174
	bool zc = false;
L
Linus Torvalds 已提交
1175 1176 1177
	long timeo;

	flags = msg->msg_flags;
W
Willem de Bruijn 已提交
1178 1179 1180 1181 1182 1183 1184

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

1185
		skb = tcp_write_queue_tail(sk);
W
Willem de Bruijn 已提交
1186 1187 1188 1189 1190 1191
		uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb));
		if (!uarg) {
			err = -ENOBUFS;
			goto out_err;
		}

E
Eric Dumazet 已提交
1192
		zc = sk->sk_route_caps & NETIF_F_SG;
1193
		if (!zc)
W
Willem de Bruijn 已提交
1194 1195 1196
			uarg->zerocopy = 0;
	}

W
Wei Wang 已提交
1197
	if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect)) {
1198
		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1199 1200 1201 1202 1203 1204
		if (err == -EINPROGRESS && copied_syn > 0)
			goto out;
		else if (err)
			goto out_err;
	}

L
Linus Torvalds 已提交
1205 1206
	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

1207 1208
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1209 1210 1211 1212 1213 1214
	/* 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)) {
1215 1216
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
1217
			goto do_error;
1218
	}
L
Linus Torvalds 已提交
1219

P
Pavel Emelyanov 已提交
1220 1221 1222
	if (unlikely(tp->repair)) {
		if (tp->repair_queue == TCP_RECV_QUEUE) {
			copied = tcp_send_rcvq(sk, msg, size);
1223
			goto out_nopush;
P
Pavel Emelyanov 已提交
1224 1225 1226 1227 1228 1229 1230 1231 1232
		}

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

		/* 'common' sending to sendq */
	}

1233 1234 1235 1236 1237 1238 1239 1240 1241
	sockc.tsflags = sk->sk_tsflags;
	if (msg->msg_controllen) {
		err = sock_cmsg_send(sk, msg, &sockc);
		if (unlikely(err)) {
			err = -EINVAL;
			goto out_err;
		}
	}

L
Linus Torvalds 已提交
1242
	/* This should be in poll */
1243
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
1244 1245 1246 1247

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

1248 1249 1250
restart:
	mss_now = tcp_send_mss(sk, &size_goal, flags);

L
Linus Torvalds 已提交
1251 1252
	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1253
		goto do_error;
L
Linus Torvalds 已提交
1254

A
Al Viro 已提交
1255
	while (msg_data_left(msg)) {
1256
		int copy = 0;
L
Linus Torvalds 已提交
1257

1258
		skb = tcp_write_queue_tail(sk);
1259 1260
		if (skb)
			copy = size_goal - skb->len;
L
Linus Torvalds 已提交
1261

1262
		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1263
			bool first_skb;
1264
			int linear;
1265

L
Linus Torvalds 已提交
1266
new_segment:
1267 1268 1269 1270 1271
			/* Allocate new segment. If the interface is SG,
			 * allocate skb fitting to single page.
			 */
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;
L
Linus Torvalds 已提交
1272

1273 1274
			if (process_backlog && sk_flush_backlog(sk)) {
				process_backlog = false;
1275
				goto restart;
1276
			}
1277
			first_skb = tcp_rtx_and_write_queues_empty(sk);
E
Eric Dumazet 已提交
1278
			linear = select_size(first_skb, zc);
1279
			skb = sk_stream_alloc_skb(sk, linear, sk->sk_allocation,
1280
						  first_skb);
1281 1282
			if (!skb)
				goto wait_for_memory;
L
Linus Torvalds 已提交
1283

1284
			process_backlog = true;
E
Eric Dumazet 已提交
1285
			skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1286

1287 1288
			skb_entail(sk, skb);
			copy = size_goal;
1289

1290 1291 1292 1293 1294 1295 1296
			/* 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
1297

1298
		/* Try to append data to the end of skb. */
A
Al Viro 已提交
1299 1300
		if (copy > msg_data_left(msg))
			copy = msg_data_left(msg);
1301 1302

		/* Where to copy to? */
1303
		if (skb_availroom(skb) > 0 && !zc) {
1304 1305 1306 1307 1308
			/* 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;
1309
		} else if (!zc) {
1310 1311 1312 1313 1314 1315
			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;
1316

1317 1318
			if (!skb_can_coalesce(skb, i, pfrag->page,
					      pfrag->offset)) {
E
Eric Dumazet 已提交
1319
				if (i >= sysctl_max_skb_frags) {
1320 1321
					tcp_mark_push(tp, skb);
					goto new_segment;
L
Linus Torvalds 已提交
1322
				}
1323
				merge = false;
L
Linus Torvalds 已提交
1324 1325
			}

1326 1327 1328 1329
			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
1330

1331 1332 1333 1334 1335 1336
			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
1337

1338 1339 1340 1341 1342 1343
			/* 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);
1344
				page_ref_inc(pfrag->page);
1345
			}
1346
			pfrag->offset += copy;
W
Willem de Bruijn 已提交
1347 1348
		} else {
			err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
W
Willem de Bruijn 已提交
1349 1350
			if (err == -EMSGSIZE || err == -EEXIST) {
				tcp_mark_push(tp, skb);
W
Willem de Bruijn 已提交
1351
				goto new_segment;
W
Willem de Bruijn 已提交
1352
			}
W
Willem de Bruijn 已提交
1353 1354 1355
			if (err < 0)
				goto do_error;
			copy = err;
1356 1357 1358 1359 1360 1361 1362 1363
		}

		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
1364

1365
		copied += copy;
A
Al Viro 已提交
1366
		if (!msg_data_left(msg)) {
1367 1368
			if (unlikely(flags & MSG_EOR))
				TCP_SKB_CB(skb)->eor = 1;
1369 1370
			goto out;
		}
L
Linus Torvalds 已提交
1371

1372
		if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair))
L
Linus Torvalds 已提交
1373 1374
			continue;

1375 1376 1377 1378 1379 1380 1381
		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
1382
wait_for_sndbuf:
1383
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
L
Linus Torvalds 已提交
1384
wait_for_memory:
1385 1386 1387
		if (copied)
			tcp_push(sk, flags & ~MSG_MORE, mss_now,
				 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1388

1389 1390
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
1391
			goto do_error;
L
Linus Torvalds 已提交
1392

1393
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1394 1395 1396
	}

out:
1397
	if (copied) {
E
Eric Dumazet 已提交
1398
		tcp_tx_timestamp(sk, sockc.tsflags);
E
Eric Dumazet 已提交
1399
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1400
	}
1401
out_nopush:
W
Willem de Bruijn 已提交
1402
	sock_zerocopy_put(uarg);
1403
	return copied + copied_syn;
L
Linus Torvalds 已提交
1404 1405 1406

do_fault:
	if (!skb->len) {
1407 1408 1409 1410 1411
		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);
1412
		sk_wmem_free_skb(sk, skb);
L
Linus Torvalds 已提交
1413 1414 1415
	}

do_error:
1416
	if (copied + copied_syn)
L
Linus Torvalds 已提交
1417 1418
		goto out;
out_err:
W
Willem de Bruijn 已提交
1419
	sock_zerocopy_put_abort(uarg);
L
Linus Torvalds 已提交
1420
	err = sk_stream_error(sk, flags, err);
1421
	/* make sure we wake any epoll edge trigger waiter */
1422 1423
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1424
		sk->sk_write_space(sk);
1425 1426
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1427 1428
	return err;
}
1429
EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440

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
1441
EXPORT_SYMBOL(tcp_sendmsg);
L
Linus Torvalds 已提交
1442 1443 1444 1445 1446 1447

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

1448
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
L
Linus Torvalds 已提交
1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471
{
	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
1472
				err = memcpy_to_msg(msg, &c, 1);
L
Linus Torvalds 已提交
1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491
			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
1492 1493 1494 1495 1496 1497 1498
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 */

1499 1500 1501 1502 1503 1504 1505
	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
1506
	skb_queue_walk(&sk->sk_write_queue, skb) {
1507
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
P
Pavel Emelyanov 已提交
1508 1509 1510 1511 1512 1513 1514 1515 1516
		if (err)
			break;

		copied += skb->len;
	}

	return err ?: copied;
}

L
Linus Torvalds 已提交
1517 1518 1519 1520 1521 1522
/* 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.
 */
1523
static void tcp_cleanup_rbuf(struct sock *sk, int copied)
L
Linus Torvalds 已提交
1524 1525
{
	struct tcp_sock *tp = tcp_sk(sk);
E
Eric Dumazet 已提交
1526
	bool time_to_ack = false;
L
Linus Torvalds 已提交
1527 1528 1529

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

1530
	WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
J
Joe Perches 已提交
1531
	     "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1532
	     tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
L
Linus Torvalds 已提交
1533

1534 1535
	if (inet_csk_ack_scheduled(sk)) {
		const struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1536 1537
		   /* Delayed ACKs frequently hit locked sockets during bulk
		    * receive. */
1538
		if (icsk->icsk_ack.blocked ||
L
Linus Torvalds 已提交
1539
		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
1540
		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
L
Linus Torvalds 已提交
1541 1542 1543 1544 1545 1546
		    /*
		     * 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.
		     */
1547 1548 1549 1550 1551
		    (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
1552
			time_to_ack = true;
L
Linus Torvalds 已提交
1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573
	}

	/* 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
1574
				time_to_ack = true;
L
Linus Torvalds 已提交
1575 1576 1577 1578 1579 1580
		}
	}
	if (time_to_ack)
		tcp_send_ack(sk);
}

1581
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
L
Linus Torvalds 已提交
1582 1583 1584 1585
{
	struct sk_buff *skb;
	u32 offset;

1586
	while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
L
Linus Torvalds 已提交
1587
		offset = seq - TCP_SKB_CB(skb)->seq;
1588 1589
		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
1590
			offset--;
1591
		}
1592
		if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
L
Linus Torvalds 已提交
1593 1594 1595
			*off = offset;
			return skb;
		}
1596 1597 1598 1599
		/* 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
1600
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628
	}
	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) {
1629 1630
			int used;
			size_t len;
L
Linus Torvalds 已提交
1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641

			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);
1642
			if (used <= 0) {
1643 1644 1645 1646
				if (!copied)
					copied = used;
				break;
			} else if (used <= len) {
L
Linus Torvalds 已提交
1647 1648 1649 1650
				seq += used;
				copied += used;
				offset += used;
			}
1651
			/* If recv_actor drops the lock (e.g. TCP splice
1652 1653 1654 1655
			 * receive) the skb pointer might be invalid when
			 * getting here: tcp_collapse might have deleted it
			 * while aggregating skbs from the socket queue.
			 */
1656 1657
			skb = tcp_recv_skb(sk, seq - 1, &offset);
			if (!skb)
L
Linus Torvalds 已提交
1658
				break;
1659 1660 1661 1662 1663
			/* 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
1664
		}
1665
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
D
Dan Williams 已提交
1666
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1667 1668 1669
			++seq;
			break;
		}
D
Dan Williams 已提交
1670
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1671 1672
		if (!desc->count)
			break;
1673
		tp->copied_seq = seq;
L
Linus Torvalds 已提交
1674 1675 1676 1677 1678 1679
	}
	tp->copied_seq = seq;

	tcp_rcv_space_adjust(sk);

	/* Clean up data we have read: This will do ACK frames. */
1680 1681
	if (copied > 0) {
		tcp_recv_skb(sk, seq, &offset);
1682
		tcp_cleanup_rbuf(sk, copied);
1683
	}
L
Linus Torvalds 已提交
1684 1685
	return copied;
}
E
Eric Dumazet 已提交
1686
EXPORT_SYMBOL(tcp_read_sock);
L
Linus Torvalds 已提交
1687

1688 1689 1690 1691 1692 1693
int tcp_peek_len(struct socket *sock)
{
	return tcp_inq(sock->sk);
}
EXPORT_SYMBOL(tcp_peek_len);

1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708
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 */
1709 1710
static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
			       struct scm_timestamping *tss)
1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748
{
	struct timeval tv;
	bool has_timestamping = false;

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

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

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

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

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

L
Linus Torvalds 已提交
1749 1750 1751 1752 1753 1754 1755 1756
/*
 *	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.
 */

1757 1758
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
1759 1760 1761 1762 1763 1764 1765 1766 1767
{
	struct tcp_sock *tp = tcp_sk(sk);
	int copied = 0;
	u32 peek_seq;
	u32 *seq;
	unsigned long used;
	int err;
	int target;		/* Read at least this many bytes */
	long timeo;
1768
	struct sk_buff *skb, *last;
I
Ilpo Järvinen 已提交
1769
	u32 urg_hole = 0;
1770 1771
	struct scm_timestamping tss;
	bool has_tss = false;
L
Linus Torvalds 已提交
1772

1773
	if (unlikely(flags & MSG_ERRQUEUE))
1774
		return inet_recv_error(sk, msg, len, addr_len);
1775

1776 1777 1778
	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
	    (sk->sk_state == TCP_ESTABLISHED))
		sk_busy_loop(sk, nonblock);
1779

L
Linus Torvalds 已提交
1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791
	lock_sock(sk);

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

	timeo = sock_rcvtimeo(sk, nonblock);

	/* Urgent data needs to be handled specially. */
	if (flags & MSG_OOB)
		goto recv_urg;

P
Pavel Emelyanov 已提交
1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806
	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
1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829
	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. */

1830
		last = skb_peek_tail(&sk->sk_receive_queue);
1831
		skb_queue_walk(&sk->sk_receive_queue, skb) {
1832
			last = skb;
L
Linus Torvalds 已提交
1833 1834 1835
			/* Now that we have two receive queues this
			 * shouldn't happen.
			 */
1836
			if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
J
Joe Perches 已提交
1837 1838 1839
				 "recvmsg bug: copied %X seq %X rcvnxt %X fl %X\n",
				 *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt,
				 flags))
L
Linus Torvalds 已提交
1840
				break;
1841

L
Linus Torvalds 已提交
1842
			offset = *seq - TCP_SKB_CB(skb)->seq;
1843 1844
			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
1845
				offset--;
1846
			}
L
Linus Torvalds 已提交
1847 1848
			if (offset < skb->len)
				goto found_ok_skb;
1849
			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1850
				goto found_fin_ok;
J
Joe Perches 已提交
1851 1852 1853
			WARN(!(flags & MSG_PEEK),
			     "recvmsg bug 2: copied %X seq %X rcvnxt %X fl %X\n",
			     *seq, TCP_SKB_CB(skb)->seq, tp->rcv_nxt, flags);
1854
		}
L
Linus Torvalds 已提交
1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865

		/* 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 ||
1866
			    signal_pending(current))
L
Linus Torvalds 已提交
1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901
				break;
		} else {
			if (sock_flag(sk, SOCK_DONE))
				break;

			if (sk->sk_err) {
				copied = sock_error(sk);
				break;
			}

			if (sk->sk_shutdown & RCV_SHUTDOWN)
				break;

			if (sk->sk_state == TCP_CLOSE) {
				if (!sock_flag(sk, SOCK_DONE)) {
					/* This occurs when user tries to read
					 * from never connected socket.
					 */
					copied = -ENOTCONN;
					break;
				}
				break;
			}

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

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

1902
		tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1903 1904 1905 1906 1907

		if (copied >= target) {
			/* Do not sleep, just process backlog. */
			release_sock(sk);
			lock_sock(sk);
1908 1909 1910
		} else {
			sk_wait_data(sk, &timeo, last);
		}
L
Linus Torvalds 已提交
1911

I
Ilpo Järvinen 已提交
1912 1913
		if ((flags & MSG_PEEK) &&
		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
1914 1915 1916
			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
1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933
			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
1934
						urg_hole++;
L
Linus Torvalds 已提交
1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945
						offset++;
						used--;
						if (!used)
							goto skip_copy;
					}
				} else
					used = urg_offset;
			}
		}

		if (!(flags & MSG_TRUNC)) {
1946
			err = skb_copy_datagram_msg(skb, offset, msg, used);
D
Dan Williams 已提交
1947 1948 1949 1950 1951
			if (err) {
				/* Exception. Bailout! */
				if (!copied)
					copied = -EFAULT;
				break;
L
Linus Torvalds 已提交
1952 1953 1954 1955 1956 1957 1958 1959 1960 1961
			}
		}

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

		tcp_rcv_space_adjust(sk);

skip_copy:
1962
		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
L
Linus Torvalds 已提交
1963
			tp->urg_data = 0;
1964 1965
			tcp_fast_path_check(sk);
		}
L
Linus Torvalds 已提交
1966 1967 1968
		if (used + offset < skb->len)
			continue;

1969 1970 1971 1972
		if (TCP_SKB_CB(skb)->has_rxtstamp) {
			tcp_update_recv_tstamps(skb, &tss);
			has_tss = true;
		}
1973
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1974
			goto found_fin_ok;
D
Dan Williams 已提交
1975 1976
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1977 1978 1979 1980 1981
		continue;

	found_fin_ok:
		/* Process the FIN. */
		++*seq;
D
Dan Williams 已提交
1982 1983
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1984 1985 1986 1987 1988 1989 1990
		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
	 */

1991 1992 1993
	if (has_tss)
		tcp_recv_timestamp(msg, sk, &tss);

L
Linus Torvalds 已提交
1994
	/* Clean up data we have read: This will do ACK frames. */
1995
	tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1996 1997 1998 1999 2000 2001 2002 2003 2004

	release_sock(sk);
	return copied;

out:
	release_sock(sk);
	return err;

recv_urg:
2005
	err = tcp_recv_urg(sk, msg, len, flags);
L
Linus Torvalds 已提交
2006
	goto out;
P
Pavel Emelyanov 已提交
2007 2008 2009 2010

recv_sndq:
	err = tcp_peek_sndq(sk, msg, len);
	goto out;
L
Linus Torvalds 已提交
2011
}
E
Eric Dumazet 已提交
2012
EXPORT_SYMBOL(tcp_recvmsg);
L
Linus Torvalds 已提交
2013

I
Ilpo Järvinen 已提交
2014 2015 2016 2017
void tcp_set_state(struct sock *sk, int state)
{
	int oldstate = sk->sk_state;

L
Lawrence Brakmo 已提交
2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040
	/* 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);
2041

I
Ilpo Järvinen 已提交
2042 2043 2044
	switch (state) {
	case TCP_ESTABLISHED:
		if (oldstate != TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2045
			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2046 2047 2048 2049
		break;

	case TCP_CLOSE:
		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2050
			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
I
Ilpo Järvinen 已提交
2051 2052 2053 2054

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2055
			inet_put_port(sk);
I
Ilpo Järvinen 已提交
2056 2057
		/* fall through */
	default:
2058
		if (oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2059
			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2060 2061 2062 2063 2064
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
2065
	inet_sk_state_store(sk, state);
I
Ilpo Järvinen 已提交
2066 2067

#ifdef STATE_TRACE
2068
	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
I
Ilpo Järvinen 已提交
2069 2070 2071 2072
#endif
}
EXPORT_SYMBOL_GPL(tcp_set_state);

L
Linus Torvalds 已提交
2073 2074 2075 2076 2077 2078 2079
/*
 *	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.
 */

2080
static const unsigned char new_state[16] = {
L
Linus Torvalds 已提交
2081
  /* current state:        new state:      action:	*/
2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094
  [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
2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108
};

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
2109
 *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
L
Linus Torvalds 已提交
2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129
 */

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
2130
EXPORT_SYMBOL(tcp_shutdown);
L
Linus Torvalds 已提交
2131

A
Arun Sharma 已提交
2132 2133 2134 2135 2136 2137 2138
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);

2139 2140 2141 2142
	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
2143 2144 2145
	return too_many_orphans || out_of_socket_memory;
}

L
Linus Torvalds 已提交
2146 2147 2148 2149
void tcp_close(struct sock *sk, long timeout)
{
	struct sk_buff *skb;
	int data_was_unread = 0;
H
Herbert Xu 已提交
2150
	int state;
L
Linus Torvalds 已提交
2151 2152 2153 2154 2155 2156 2157 2158

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

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

		/* Special case. */
2159
		inet_csk_listen_stop(sk);
L
Linus Torvalds 已提交
2160 2161 2162 2163 2164 2165 2166 2167 2168

		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) {
2169 2170 2171 2172
		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
2173 2174 2175 2176
		data_was_unread += len;
		__kfree_skb(skb);
	}

2177
	sk_mem_reclaim(sk);
L
Linus Torvalds 已提交
2178

2179 2180 2181 2182
	/* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
	if (sk->sk_state == TCP_CLOSE)
		goto adjudge_to_death;

2183 2184 2185 2186 2187 2188
	/* 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
2189
	 */
P
Pavel Emelyanov 已提交
2190 2191 2192
	if (unlikely(tcp_sk(sk)->repair)) {
		sk->sk_prot->disconnect(sk, 0);
	} else if (data_was_unread) {
L
Linus Torvalds 已提交
2193
		/* Unread data was tossed, zap the connection. */
2194
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
L
Linus Torvalds 已提交
2195
		tcp_set_state(sk, TCP_CLOSE);
2196
		tcp_send_active_reset(sk, sk->sk_allocation);
L
Linus Torvalds 已提交
2197 2198 2199
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
2200
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
L
Linus Torvalds 已提交
2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225
	} 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
2226 2227 2228 2229
		 * 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
2230 2231 2232 2233 2234 2235 2236
		 */
		tcp_send_fin(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
H
Herbert Xu 已提交
2237 2238 2239 2240
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

L
Linus Torvalds 已提交
2241 2242 2243 2244 2245
	/* 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
2246
	 *  to finish close. No need to check for user refs.
L
Linus Torvalds 已提交
2247 2248 2249
	 */
	local_bh_disable();
	bh_lock_sock(sk);
2250
	WARN_ON(sock_owned_by_user(sk));
L
Linus Torvalds 已提交
2251

H
Herbert Xu 已提交
2252 2253
	percpu_counter_inc(sk->sk_prot->orphan_count);

H
Herbert Xu 已提交
2254 2255 2256
	/* 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
2257 2258 2259 2260

	/*	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.
2261
	 *	We use a 1 minute timeout (about the same as BSD) then kill
L
Linus Torvalds 已提交
2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276
	 *	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);
2277
			__NET_INC_STATS(sock_net(sk),
2278
					LINUX_MIB_TCPABORTONLINGER);
L
Linus Torvalds 已提交
2279
		} else {
2280
			const int tmo = tcp_fin_time(sk);
L
Linus Torvalds 已提交
2281 2282

			if (tmo > TCP_TIMEWAIT_LEN) {
2283 2284
				inet_csk_reset_keepalive_timer(sk,
						tmo - TCP_TIMEWAIT_LEN);
L
Linus Torvalds 已提交
2285 2286 2287 2288 2289 2290 2291
			} else {
				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
				goto out;
			}
		}
	}
	if (sk->sk_state != TCP_CLOSE) {
2292
		sk_mem_reclaim(sk);
A
Arun Sharma 已提交
2293
		if (tcp_check_oom(sk, 0)) {
L
Linus Torvalds 已提交
2294 2295
			tcp_set_state(sk, TCP_CLOSE);
			tcp_send_active_reset(sk, GFP_ATOMIC);
2296
			__NET_INC_STATS(sock_net(sk),
2297
					LINUX_MIB_TCPABORTONMEMORY);
2298 2299 2300
		} 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
2301 2302 2303
		}
	}

2304 2305 2306 2307 2308 2309
	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.
		 */
2310
		if (req)
2311
			reqsk_fastopen_remove(sk, req, false);
2312
		inet_csk_destroy_sock(sk);
2313
	}
L
Linus Torvalds 已提交
2314 2315 2316 2317 2318 2319 2320
	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}
E
Eric Dumazet 已提交
2321
EXPORT_SYMBOL(tcp_close);
L
Linus Torvalds 已提交
2322 2323 2324

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

E
Eric Dumazet 已提交
2325
static inline bool tcp_need_reset(int state)
L
Linus Torvalds 已提交
2326 2327 2328 2329 2330 2331
{
	return (1 << state) &
	       (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
		TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
}

2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347
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);
	}
}

2348 2349 2350 2351 2352 2353 2354 2355 2356
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);
	}
2357
	tcp_rtx_queue_purge(sk);
2358 2359 2360 2361 2362
	INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
	sk_mem_reclaim(sk);
	tcp_clear_all_retrans_hints(tcp_sk(sk));
}

L
Linus Torvalds 已提交
2363 2364 2365
int tcp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
2366
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2367 2368 2369 2370 2371 2372 2373 2374 2375
	struct tcp_sock *tp = tcp_sk(sk);
	int err = 0;
	int old_state = sk->sk_state;

	if (old_state != TCP_CLOSE)
		tcp_set_state(sk, TCP_CLOSE);

	/* ABORT function of RFC793 */
	if (old_state == TCP_LISTEN) {
2376
		inet_csk_listen_stop(sk);
P
Pavel Emelyanov 已提交
2377 2378
	} else if (unlikely(tp->repair)) {
		sk->sk_err = ECONNABORTED;
L
Linus Torvalds 已提交
2379 2380 2381
	} 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
2382
		/* The last check adjusts for discrepancy of Linux wrt. RFC
L
Linus Torvalds 已提交
2383 2384 2385 2386 2387 2388 2389 2390 2391
		 * 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);
2392
	tcp_write_queue_purge(sk);
2393
	tcp_fastopen_active_disable_ofo_check(sk);
2394
	skb_rbtree_purge(&tp->out_of_order_queue);
L
Linus Torvalds 已提交
2395

E
Eric Dumazet 已提交
2396
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
2397 2398 2399 2400 2401 2402

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

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);
2403
	tp->srtt_us = 0;
2404 2405
	tp->write_seq += tp->max_window + 2;
	if (tp->write_seq == 0)
L
Linus Torvalds 已提交
2406
		tp->write_seq = 1;
2407
	icsk->icsk_backoff = 0;
L
Linus Torvalds 已提交
2408
	tp->snd_cwnd = 2;
2409
	icsk->icsk_probes_out = 0;
L
Linus Torvalds 已提交
2410
	tp->packets_out = 0;
I
Ilpo Järvinen 已提交
2411
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
L
Linus Torvalds 已提交
2412
	tp->snd_cwnd_cnt = 0;
2413
	tp->window_clamp = 0;
2414
	tcp_set_ca_state(sk, TCP_CA_Open);
2415
	tp->is_sack_reneg = 0;
L
Linus Torvalds 已提交
2416
	tcp_clear_retrans(tp);
2417
	inet_csk_delack_init(sk);
2418 2419 2420 2421
	/* 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;
2422
	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
L
Linus Torvalds 已提交
2423
	__sk_dst_reset(sk);
2424 2425
	dst_release(sk->sk_rx_dst);
	sk->sk_rx_dst = NULL;
2426
	tcp_saved_syn_free(tp);
L
Linus Torvalds 已提交
2427

2428 2429 2430 2431
	/* Clean up fastopen related fields */
	tcp_free_fastopen_req(tp);
	inet->defer_connect = 0;

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

2434 2435 2436 2437 2438 2439
	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
2440 2441 2442
	sk->sk_error_report(sk);
	return err;
}
E
Eric Dumazet 已提交
2443
EXPORT_SYMBOL(tcp_disconnect);
L
Linus Torvalds 已提交
2444

E
Eric Dumazet 已提交
2445
static inline bool tcp_can_repair_sock(const struct sock *sk)
P
Pavel Emelyanov 已提交
2446
{
2447
	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2448
		(sk->sk_state != TCP_LISTEN);
P
Pavel Emelyanov 已提交
2449 2450
}

2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482
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;
}

2483
static int tcp_repair_options_est(struct sock *sk,
2484
		struct tcp_repair_opt __user *optbuf, unsigned int len)
2485
{
2486
	struct tcp_sock *tp = tcp_sk(sk);
2487
	struct tcp_repair_opt opt;
2488

2489 2490
	while (len >= sizeof(opt)) {
		if (copy_from_user(&opt, optbuf, sizeof(opt)))
2491 2492 2493
			return -EFAULT;

		optbuf++;
2494
		len -= sizeof(opt);
2495

2496 2497 2498
		switch (opt.opt_code) {
		case TCPOPT_MSS:
			tp->rx_opt.mss_clamp = opt.opt_val;
2499
			tcp_mtup_init(sk);
2500
			break;
2501
		case TCPOPT_WINDOW:
2502 2503 2504 2505
			{
				u16 snd_wscale = opt.opt_val & 0xFFFF;
				u16 rcv_wscale = opt.opt_val >> 16;

2506
				if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2507
					return -EFBIG;
2508

2509 2510 2511 2512
				tp->rx_opt.snd_wscale = snd_wscale;
				tp->rx_opt.rcv_wscale = rcv_wscale;
				tp->rx_opt.wscale_ok = 1;
			}
2513 2514
			break;
		case TCPOPT_SACK_PERM:
2515 2516 2517
			if (opt.opt_val != 0)
				return -EINVAL;

2518 2519 2520
			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
			break;
		case TCPOPT_TIMESTAMP:
2521 2522 2523
			if (opt.opt_val != 0)
				return -EINVAL;

2524 2525 2526 2527 2528 2529 2530 2531
			tp->rx_opt.tstamp_ok = 1;
			break;
		}
	}

	return 0;
}

L
Linus Torvalds 已提交
2532 2533 2534
/*
 *	Socket option code for TCP.
 */
2535
static int do_tcp_setsockopt(struct sock *sk, int level,
2536
		int optname, char __user *optval, unsigned int optlen)
L
Linus Torvalds 已提交
2537 2538
{
	struct tcp_sock *tp = tcp_sk(sk);
2539
	struct inet_connection_sock *icsk = inet_csk(sk);
2540
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2541 2542 2543
	int val;
	int err = 0;

2544 2545 2546
	/* These are data/string values, all the others are ints */
	switch (optname) {
	case TCP_CONGESTION: {
2547 2548 2549 2550 2551 2552
		char name[TCP_CA_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
2553
					min_t(long, TCP_CA_NAME_MAX-1, optlen));
2554 2555 2556 2557 2558
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
2559
		err = tcp_set_congestion_control(sk, name, true, true);
2560 2561 2562
		release_sock(sk);
		return err;
	}
D
Dave Watson 已提交
2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580
	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;
	}
2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591
	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));
	}
2592 2593 2594
	default:
		/* fallthru */
		break;
2595
	}
2596

L
Linus Torvalds 已提交
2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608
	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
2609 2610
		 * know which interface is going to be used
		 */
2611
		if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
L
Linus Torvalds 已提交
2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628
			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;
2629
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2630 2631 2632 2633 2634
		} else {
			tp->nonagle &= ~TCP_NAGLE_OFF;
		}
		break;

A
Andreas Petlund 已提交
2635 2636 2637 2638 2639 2640 2641
	case TCP_THIN_LINEAR_TIMEOUTS:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->thin_lto = val;
		break;

A
Andreas Petlund 已提交
2642 2643 2644 2645 2646
	case TCP_THIN_DUPACK:
		if (val < 0 || val > 1)
			err = -EINVAL;
		break;

P
Pavel Emelyanov 已提交
2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682
	case TCP_REPAIR:
		if (!tcp_can_repair_sock(sk))
			err = -EPERM;
		else if (val == 1) {
			tp->repair = 1;
			sk->sk_reuse = SK_FORCE_REUSE;
			tp->repair_queue = TCP_NO_QUEUE;
		} else if (val == 0) {
			tp->repair = 0;
			sk->sk_reuse = SK_NO_REUSE;
			tcp_send_window_probe(sk);
		} else
			err = -EINVAL;

		break;

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

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

2683 2684 2685 2686
	case TCP_REPAIR_OPTIONS:
		if (!tp->repair)
			err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
2687
			err = tcp_repair_options_est(sk,
2688 2689
					(struct tcp_repair_opt __user *)optval,
					optlen);
2690 2691 2692 2693
		else
			err = -EPERM;
		break;

L
Linus Torvalds 已提交
2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711
	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;
2712
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723
		}
		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))) {
2724
				u32 elapsed = keepalive_time_elapsed(tp);
L
Linus Torvalds 已提交
2725 2726 2727 2728
				if (tp->keepalive_time > elapsed)
					elapsed = tp->keepalive_time - elapsed;
				else
					elapsed = 0;
2729
				inet_csk_reset_keepalive_timer(sk, elapsed);
L
Linus Torvalds 已提交
2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748
			}
		}
		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
2749
			icsk->icsk_syn_retries = val;
L
Linus Torvalds 已提交
2750 2751
		break;

2752 2753 2754 2755 2756 2757 2758
	case TCP_SAVE_SYN:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->save_syn = val;
		break;

L
Linus Torvalds 已提交
2759 2760 2761
	case TCP_LINGER2:
		if (val < 0)
			tp->linger2 = -1;
2762
		else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
L
Linus Torvalds 已提交
2763 2764 2765 2766 2767 2768
			tp->linger2 = 0;
		else
			tp->linger2 = val * HZ;
		break;

	case TCP_DEFER_ACCEPT:
2769 2770 2771 2772
		/* 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
2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788
		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) {
2789
			icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2790
		} else {
2791
			icsk->icsk_ack.pingpong = 0;
L
Linus Torvalds 已提交
2792 2793
			if ((1 << sk->sk_state) &
			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2794 2795
			    inet_csk_ack_scheduled(sk)) {
				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2796
				tcp_cleanup_rbuf(sk, 1);
L
Linus Torvalds 已提交
2797
				if (!(val & 1))
2798
					icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2799 2800 2801 2802
			}
		}
		break;

2803 2804
#ifdef CONFIG_TCP_MD5SIG
	case TCP_MD5SIG:
2805
	case TCP_MD5SIG_EXT:
2806
		/* Read the IP->Key mappings from userspace */
2807
		err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
2808 2809
		break;
#endif
2810
	case TCP_USER_TIMEOUT:
2811
		/* Cap the max time in ms TCP will retry or probe the window
2812 2813
		 * before giving up and aborting (ETIMEDOUT) a connection.
		 */
2814 2815 2816 2817
		if (val < 0)
			err = -EINVAL;
		else
			icsk->icsk_user_timeout = msecs_to_jiffies(val);
2818
		break;
2819 2820 2821

	case TCP_FASTOPEN:
		if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2822
		    TCPF_LISTEN))) {
2823
			tcp_fastopen_init_key_once(net);
2824

2825
			fastopen_queue_tune(sk, val);
2826
		} else {
2827
			err = -EINVAL;
2828
		}
2829
		break;
W
Wei Wang 已提交
2830 2831 2832
	case TCP_FASTOPEN_CONNECT:
		if (val > 1 || val < 0) {
			err = -EINVAL;
2833
		} else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
W
Wei Wang 已提交
2834 2835 2836 2837 2838 2839 2840 2841
			if (sk->sk_state == TCP_CLOSE)
				tp->fastopen_connect = val;
			else
				err = -EINVAL;
		} else {
			err = -EOPNOTSUPP;
		}
		break;
2842 2843 2844 2845 2846 2847 2848 2849
	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;
2850 2851 2852 2853
	case TCP_TIMESTAMP:
		if (!tp->repair)
			err = -EPERM;
		else
2854
			tp->tsoffset = val - tcp_time_stamp_raw();
2855
		break;
2856 2857 2858
	case TCP_REPAIR_WINDOW:
		err = tcp_repair_set_window(tp, optval, optlen);
		break;
2859 2860 2861 2862
	case TCP_NOTSENT_LOWAT:
		tp->notsent_lowat = val;
		sk->sk_write_space(sk);
		break;
L
Linus Torvalds 已提交
2863 2864 2865
	default:
		err = -ENOPROTOOPT;
		break;
2866 2867
	}

L
Linus Torvalds 已提交
2868 2869 2870 2871
	release_sock(sk);
	return err;
}

2872
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2873
		   unsigned int optlen)
2874
{
2875
	const struct inet_connection_sock *icsk = inet_csk(sk);
2876 2877 2878 2879 2880 2881

	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
2882
EXPORT_SYMBOL(tcp_setsockopt);
2883 2884

#ifdef CONFIG_COMPAT
2885
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2886
			  char __user *optval, unsigned int optlen)
2887
{
2888 2889 2890
	if (level != SOL_TCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
2891 2892
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
2893
EXPORT_SYMBOL(compat_tcp_setsockopt);
2894 2895
#endif

2896 2897 2898 2899 2900 2901 2902 2903 2904
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)
2905
			stats[i] += tcp_jiffies32 - tp->chrono_start;
2906 2907 2908 2909 2910 2911 2912 2913 2914
		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
2915
/* Return information about state of tcp endpoint in API format. */
2916
void tcp_get_info(struct sock *sk, struct tcp_info *info)
L
Linus Torvalds 已提交
2917
{
2918
	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
2919
	const struct inet_connection_sock *icsk = inet_csk(sk);
2920
	u32 now;
2921
	u64 rate64;
2922
	bool slow;
2923
	u32 rate;
L
Linus Torvalds 已提交
2924 2925

	memset(info, 0, sizeof(*info));
2926 2927
	if (sk->sk_type != SOCK_STREAM)
		return;
L
Linus Torvalds 已提交
2928

2929
	info->tcpi_state = inet_sk_state_load(sk);
2930

2931 2932 2933
	/* Report meaningful fields for all TCP states, including listeners */
	rate = READ_ONCE(sk->sk_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2934
	info->tcpi_pacing_rate = rate64;
2935 2936 2937

	rate = READ_ONCE(sk->sk_max_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2938
	info->tcpi_max_pacing_rate = rate64;
2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951

	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;
	}
2952 2953 2954

	slow = lock_sock_fast(sk);

2955
	info->tcpi_ca_state = icsk->icsk_ca_state;
2956
	info->tcpi_retransmits = icsk->icsk_retransmits;
2957
	info->tcpi_probes = icsk->icsk_probes_out;
2958
	info->tcpi_backoff = icsk->icsk_backoff;
L
Linus Torvalds 已提交
2959 2960 2961

	if (tp->rx_opt.tstamp_ok)
		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2962
	if (tcp_is_sack(tp))
L
Linus Torvalds 已提交
2963 2964 2965 2966 2967
		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;
2968
	}
L
Linus Torvalds 已提交
2969

E
Eric Dumazet 已提交
2970
	if (tp->ecn_flags & TCP_ECN_OK)
L
Linus Torvalds 已提交
2971
		info->tcpi_options |= TCPI_OPT_ECN;
E
Eric Dumazet 已提交
2972 2973
	if (tp->ecn_flags & TCP_ECN_SEEN)
		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Y
Yuchung Cheng 已提交
2974 2975
	if (tp->syn_data_acked)
		info->tcpi_options |= TCPI_OPT_SYN_DATA;
L
Linus Torvalds 已提交
2976

2977 2978
	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2979
	info->tcpi_snd_mss = tp->mss_cache;
2980
	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
L
Linus Torvalds 已提交
2981

2982 2983 2984
	info->tcpi_unacked = tp->packets_out;
	info->tcpi_sacked = tp->sacked_out;

L
Linus Torvalds 已提交
2985 2986 2987
	info->tcpi_lost = tp->lost_out;
	info->tcpi_retrans = tp->retrans_out;

2988
	now = tcp_jiffies32;
L
Linus Torvalds 已提交
2989
	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2990
	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
L
Linus Torvalds 已提交
2991 2992
	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);

2993
	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
L
Linus Torvalds 已提交
2994
	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2995 2996
	info->tcpi_rtt = tp->srtt_us >> 3;
	info->tcpi_rttvar = tp->mdev_us >> 2;
L
Linus Torvalds 已提交
2997 2998 2999
	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
	info->tcpi_advmss = tp->advmss;

3000
	info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
L
Linus Torvalds 已提交
3001 3002 3003
	info->tcpi_rcv_space = tp->rcvq_space.space;

	info->tcpi_total_retrans = tp->total_retrans;
3004

3005 3006
	info->tcpi_bytes_acked = tp->bytes_acked;
	info->tcpi_bytes_received = tp->bytes_received;
3007
	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
3008
	tcp_get_info_chrono_stats(tp, info);
3009

3010 3011
	info->tcpi_segs_out = tp->segs_out;
	info->tcpi_segs_in = tp->segs_in;
3012 3013

	info->tcpi_min_rtt = tcp_min_rtt(tp);
3014 3015
	info->tcpi_data_segs_in = tp->data_segs_in;
	info->tcpi_data_segs_out = tp->data_segs_out;
Y
Yuchung Cheng 已提交
3016 3017

	info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
3018 3019
	rate64 = tcp_compute_delivery_rate(tp);
	if (rate64)
3020
		info->tcpi_delivery_rate = rate64;
3021
	unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
3022 3023 3024
}
EXPORT_SYMBOL_GPL(tcp_get_info);

3025 3026 3027 3028 3029
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;
3030 3031
	u64 rate64;
	u32 rate;
3032

3033
	stats = alloc_skb(7 * nla_total_size_64bit(sizeof(u64)) +
3034
			  4 * nla_total_size(sizeof(u32)) +
3035
			  3 * nla_total_size(sizeof(u8)), GFP_ATOMIC);
3036 3037 3038 3039 3040 3041 3042 3043 3044 3045
	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);
3046 3047 3048 3049
	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);
3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063

	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);
3064 3065

	nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una);
3066
	nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state);
3067 3068 3069
	return stats;
}

3070 3071
static int do_tcp_getsockopt(struct sock *sk, int level,
		int optname, char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
3072
{
3073
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
3074
	struct tcp_sock *tp = tcp_sk(sk);
3075
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087
	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:
3088
		val = tp->mss_cache;
L
Linus Torvalds 已提交
3089 3090
		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			val = tp->rx_opt.user_mss;
3091 3092
		if (tp->repair)
			val = tp->rx_opt.mss_clamp;
L
Linus Torvalds 已提交
3093 3094 3095 3096 3097 3098 3099 3100
		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
3101
		val = keepalive_time_when(tp) / HZ;
L
Linus Torvalds 已提交
3102 3103
		break;
	case TCP_KEEPINTVL:
E
Eric Dumazet 已提交
3104
		val = keepalive_intvl_when(tp) / HZ;
L
Linus Torvalds 已提交
3105 3106
		break;
	case TCP_KEEPCNT:
E
Eric Dumazet 已提交
3107
		val = keepalive_probes(tp);
L
Linus Torvalds 已提交
3108 3109
		break;
	case TCP_SYNCNT:
3110
		val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
L
Linus Torvalds 已提交
3111 3112 3113 3114
		break;
	case TCP_LINGER2:
		val = tp->linger2;
		if (val >= 0)
3115
			val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
L
Linus Torvalds 已提交
3116 3117
		break;
	case TCP_DEFER_ACCEPT:
3118 3119
		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
3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138
		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;
	}
3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158
	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
3159
	case TCP_QUICKACK:
3160
		val = !icsk->icsk_ack.pingpong;
L
Linus Torvalds 已提交
3161
		break;
3162 3163 3164 3165 3166 3167 3168

	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;
3169
		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
3170 3171
			return -EFAULT;
		return 0;
3172

D
Dave Watson 已提交
3173 3174 3175 3176
	case TCP_ULP:
		if (get_user(len, optlen))
			return -EFAULT;
		len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
3177 3178 3179 3180 3181
		if (!icsk->icsk_ulp_ops) {
			if (put_user(0, optlen))
				return -EFAULT;
			return 0;
		}
D
Dave Watson 已提交
3182 3183 3184 3185 3186 3187
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len))
			return -EFAULT;
		return 0;

3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209
	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;
	}
3210 3211 3212
	case TCP_THIN_LINEAR_TIMEOUTS:
		val = tp->thin_lto;
		break;
Y
Yuchung Cheng 已提交
3213

3214
	case TCP_THIN_DUPACK:
Y
Yuchung Cheng 已提交
3215
		val = 0;
3216
		break;
3217

P
Pavel Emelyanov 已提交
3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228
	case TCP_REPAIR:
		val = tp->repair;
		break;

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

3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250
	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
3251 3252 3253 3254 3255 3256 3257 3258 3259
	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;

3260 3261 3262
	case TCP_USER_TIMEOUT:
		val = jiffies_to_msecs(icsk->icsk_user_timeout);
		break;
3263 3264

	case TCP_FASTOPEN:
3265
		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3266 3267
		break;

W
Wei Wang 已提交
3268 3269 3270 3271
	case TCP_FASTOPEN_CONNECT:
		val = tp->fastopen_connect;
		break;

3272 3273 3274 3275
	case TCP_FASTOPEN_NO_COOKIE:
		val = tp->fastopen_no_cookie;
		break;

3276
	case TCP_TIMESTAMP:
3277
		val = tcp_time_stamp_raw() + tp->tsoffset;
3278
		break;
3279 3280 3281
	case TCP_NOTSENT_LOWAT:
		val = tp->notsent_lowat;
		break;
3282 3283 3284 3285 3286 3287 3288 3289 3290
	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) {
3291 3292 3293 3294 3295 3296 3297 3298 3299
			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];
3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317
			if (put_user(len, optlen)) {
				release_sock(sk);
				return -EFAULT;
			}
			if (copy_to_user(optval, tp->saved_syn + 1, len)) {
				release_sock(sk);
				return -EFAULT;
			}
			tcp_saved_syn_free(tp);
			release_sock(sk);
		} else {
			release_sock(sk);
			len = 0;
			if (put_user(len, optlen))
				return -EFAULT;
		}
		return 0;
	}
L
Linus Torvalds 已提交
3318 3319
	default:
		return -ENOPROTOOPT;
3320
	}
L
Linus Torvalds 已提交
3321 3322 3323 3324 3325 3326 3327 3328

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

3329 3330 3331 3332 3333 3334 3335 3336 3337 3338
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
3339
EXPORT_SYMBOL(tcp_getsockopt);
3340 3341

#ifdef CONFIG_COMPAT
3342 3343
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
			  char __user *optval, int __user *optlen)
3344
{
3345 3346 3347
	if (level != SOL_TCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
3348 3349
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
3350
EXPORT_SYMBOL(compat_tcp_getsockopt);
3351
#endif
L
Linus Torvalds 已提交
3352

3353
#ifdef CONFIG_TCP_MD5SIG
E
Eric Dumazet 已提交
3354
static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3355
static DEFINE_MUTEX(tcp_md5sig_mutex);
E
Eric Dumazet 已提交
3356
static bool tcp_md5sig_pool_populated = false;
3357

3358
static void __tcp_alloc_md5sig_pool(void)
3359
{
H
Herbert Xu 已提交
3360
	struct crypto_ahash *hash;
3361 3362
	int cpu;

H
Herbert Xu 已提交
3363
	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3364
	if (IS_ERR(hash))
H
Herbert Xu 已提交
3365 3366
		return;

3367
	for_each_possible_cpu(cpu) {
3368
		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
H
Herbert Xu 已提交
3369
		struct ahash_request *req;
3370

3371 3372 3373 3374 3375 3376 3377 3378 3379
		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
3380 3381 3382 3383 3384 3385 3386 3387 3388 3389
		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;
3390
	}
E
Eric Dumazet 已提交
3391 3392
	/* before setting tcp_md5sig_pool_populated, we must commit all writes
	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3393 3394
	 */
	smp_wmb();
E
Eric Dumazet 已提交
3395
	tcp_md5sig_pool_populated = true;
3396 3397
}

3398
bool tcp_alloc_md5sig_pool(void)
3399
{
E
Eric Dumazet 已提交
3400
	if (unlikely(!tcp_md5sig_pool_populated)) {
3401 3402
		mutex_lock(&tcp_md5sig_mutex);

E
Eric Dumazet 已提交
3403
		if (!tcp_md5sig_pool_populated)
3404 3405 3406
			__tcp_alloc_md5sig_pool();

		mutex_unlock(&tcp_md5sig_mutex);
3407
	}
E
Eric Dumazet 已提交
3408
	return tcp_md5sig_pool_populated;
3409 3410 3411
}
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);

E
Eric Dumazet 已提交
3412 3413 3414 3415 3416 3417 3418 3419 3420

/**
 *	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)
3421
{
E
Eric Dumazet 已提交
3422
	local_bh_disable();
3423

E
Eric Dumazet 已提交
3424 3425 3426 3427 3428
	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
3429 3430 3431 3432
	local_bh_enable();
	return NULL;
}
EXPORT_SYMBOL(tcp_get_md5sig_pool);
3433

3434
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3435
			  const struct sk_buff *skb, unsigned int header_len)
3436 3437 3438
{
	struct scatterlist sg;
	const struct tcphdr *tp = tcp_hdr(skb);
H
Herbert Xu 已提交
3439
	struct ahash_request *req = hp->md5_req;
3440 3441 3442
	unsigned int i;
	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
					   skb_headlen(skb) - header_len : 0;
3443
	const struct skb_shared_info *shi = skb_shinfo(skb);
3444
	struct sk_buff *frag_iter;
3445 3446 3447 3448

	sg_init_table(&sg, 1);

	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
H
Herbert Xu 已提交
3449 3450
	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
	if (crypto_ahash_update(req))
3451 3452 3453 3454
		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
3455 3456 3457 3458 3459
		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
3460 3461
		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
		if (crypto_ahash_update(req))
3462 3463 3464
			return 1;
	}

3465 3466 3467 3468
	skb_walk_frags(skb, frag_iter)
		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
			return 1;

3469 3470 3471 3472
	return 0;
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

3473
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3474 3475 3476 3477
{
	struct scatterlist sg;

	sg_init_one(&sg, key->key, key->keylen);
H
Herbert Xu 已提交
3478 3479
	ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
	return crypto_ahash_update(hp->md5_req);
3480 3481 3482
}
EXPORT_SYMBOL(tcp_md5_hash_key);

3483 3484
#endif

A
Andi Kleen 已提交
3485 3486
void tcp_done(struct sock *sk)
{
3487 3488
	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;

3489
	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3490
		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
A
Andi Kleen 已提交
3491 3492 3493

	tcp_set_state(sk, TCP_CLOSE);
	tcp_clear_xmit_timers(sk);
3494
	if (req)
3495
		reqsk_fastopen_remove(sk, req, false);
A
Andi Kleen 已提交
3496 3497 3498 3499 3500 3501 3502 3503 3504 3505

	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);

3506 3507 3508
int tcp_abort(struct sock *sk, int err)
{
	if (!sk_fullsock(sk)) {
3509 3510 3511 3512 3513 3514 3515 3516 3517
		if (sk->sk_state == TCP_NEW_SYN_RECV) {
			struct request_sock *req = inet_reqsk(sk);

			local_bh_disable();
			inet_csk_reqsk_queue_drop_and_put(req->rsk_listener,
							  req);
			local_bh_enable();
			return 0;
		}
3518 3519 3520 3521 3522 3523
		return -EOPNOTSUPP;
	}

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

3524 3525 3526 3527 3528
	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);
		inet_csk_listen_stop(sk);
	}

3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549
	/* Don't race with BH socket closes such as inet_csk_listen_stop. */
	local_bh_disable();
	bh_lock_sock(sk);

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

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

3550
extern struct tcp_congestion_ops tcp_reno;
L
Linus Torvalds 已提交
3551 3552 3553 3554

static __initdata unsigned long thash_entries;
static int __init set_thash_entries(char *str)
{
3555 3556
	ssize_t ret;

L
Linus Torvalds 已提交
3557 3558
	if (!str)
		return 0;
3559 3560 3561 3562 3563

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

L
Linus Torvalds 已提交
3564 3565 3566 3567
	return 1;
}
__setup("thash_entries=", set_thash_entries);

F
Fabian Frederick 已提交
3568
static void __init tcp_init_mem(void)
3569
{
E
Eric Dumazet 已提交
3570 3571
	unsigned long limit = nr_free_buffer_pages() / 16;

3572
	limit = max(limit, 128UL);
E
Eric Dumazet 已提交
3573 3574 3575
	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 % */
3576 3577
}

L
Linus Torvalds 已提交
3578 3579
void __init tcp_init(void)
{
3580
	int max_rshare, max_wshare, cnt;
3581
	unsigned long limit;
3582
	unsigned int i;
L
Linus Torvalds 已提交
3583

3584 3585
	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
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Linus Torvalds 已提交
3586

3587 3588
	percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
	percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3589
	inet_hashinfo_init(&tcp_hashinfo);
3590 3591 3592
	inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash",
			    thash_entries, 21,  /* one slot per 2 MB*/
			    0, 64 * 1024);
3593 3594 3595
	tcp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("tcp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
3596
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
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Linus Torvalds 已提交
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	/* Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
3603
	tcp_hashinfo.ehash =
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Linus Torvalds 已提交
3604
		alloc_large_system_hash("TCP established",
3605
					sizeof(struct inet_ehash_bucket),
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Linus Torvalds 已提交
3606
					thash_entries,
E
Eric Dumazet 已提交
3607
					17, /* one slot per 128 KB of memory */
3608
					0,
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Linus Torvalds 已提交
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					NULL,
3610
					&tcp_hashinfo.ehash_mask,
3611
					0,
3612
					thash_entries ? 0 : 512 * 1024);
E
Eric Dumazet 已提交
3613
	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3614
		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
E
Eric Dumazet 已提交
3615

3616 3617
	if (inet_ehash_locks_alloc(&tcp_hashinfo))
		panic("TCP: failed to alloc ehash_locks");
3618
	tcp_hashinfo.bhash =
L
Linus Torvalds 已提交
3619
		alloc_large_system_hash("TCP bind",
3620
					sizeof(struct inet_bind_hashbucket),
3621
					tcp_hashinfo.ehash_mask + 1,
E
Eric Dumazet 已提交
3622
					17, /* one slot per 128 KB of memory */
3623
					0,
3624
					&tcp_hashinfo.bhash_size,
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Linus Torvalds 已提交
3625
					NULL,
3626
					0,
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Linus Torvalds 已提交
3627
					64 * 1024);
3628
	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3629 3630 3631
	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);
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Linus Torvalds 已提交
3632 3633
	}

E
Eric Dumazet 已提交
3634 3635 3636

	cnt = tcp_hashinfo.ehash_mask + 1;
	sysctl_tcp_max_orphans = cnt / 2;
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Linus Torvalds 已提交
3637

3638
	tcp_init_mem();
3639
	/* Set per-socket limits to no more than 1/128 the pressure threshold */
E
Eric Dumazet 已提交
3640
	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3641 3642
	max_wshare = min(4UL*1024*1024, limit);
	max_rshare = min(6UL*1024*1024, limit);
3643

3644 3645 3646
	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);
3647

3648 3649 3650
	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);
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Linus Torvalds 已提交
3651

3652
	pr_info("Hash tables configured (established %u bind %u)\n",
J
Joe Perches 已提交
3653
		tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3654

3655
	tcp_v4_init();
3656
	tcp_metrics_init();
3657
	BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
E
Eric Dumazet 已提交
3658
	tcp_tasklet_init();
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Linus Torvalds 已提交
3659
}