tcp.c 94.9 KB
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/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Implementation of the Transmission Control Protocol(TCP).
 *
8
 * Authors:	Ross Biro
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 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Mark Evans, <evansmp@uhura.aston.ac.uk>
 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
 *		Florian La Roche, <flla@stud.uni-sb.de>
 *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
 *		Linus Torvalds, <torvalds@cs.helsinki.fi>
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *		Matthew Dillon, <dillon@apollo.west.oic.com>
 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
 *		Jorge Cwik, <jorge@laser.satlink.net>
 *
 * Fixes:
 *		Alan Cox	:	Numerous verify_area() calls
 *		Alan Cox	:	Set the ACK bit on a reset
 *		Alan Cox	:	Stopped it crashing if it closed while
 *					sk->inuse=1 and was trying to connect
 *					(tcp_err()).
 *		Alan Cox	:	All icmp error handling was broken
 *					pointers passed where wrong and the
 *					socket was looked up backwards. Nobody
 *					tested any icmp error code obviously.
 *		Alan Cox	:	tcp_err() now handled properly. It
 *					wakes people on errors. poll
 *					behaves and the icmp error race
 *					has gone by moving it into sock.c
 *		Alan Cox	:	tcp_send_reset() fixed to work for
 *					everything not just packets for
 *					unknown sockets.
 *		Alan Cox	:	tcp option processing.
 *		Alan Cox	:	Reset tweaked (still not 100%) [Had
 *					syn rule wrong]
 *		Herp Rosmanith  :	More reset fixes
 *		Alan Cox	:	No longer acks invalid rst frames.
 *					Acking any kind of RST is right out.
 *		Alan Cox	:	Sets an ignore me flag on an rst
 *					receive otherwise odd bits of prattle
 *					escape still
 *		Alan Cox	:	Fixed another acking RST frame bug.
 *					Should stop LAN workplace lockups.
 *		Alan Cox	: 	Some tidyups using the new skb list
 *					facilities
 *		Alan Cox	:	sk->keepopen now seems to work
 *		Alan Cox	:	Pulls options out correctly on accepts
 *		Alan Cox	:	Fixed assorted sk->rqueue->next errors
 *		Alan Cox	:	PSH doesn't end a TCP read. Switched a
 *					bit to skb ops.
 *		Alan Cox	:	Tidied tcp_data to avoid a potential
 *					nasty.
 *		Alan Cox	:	Added some better commenting, as the
 *					tcp is hard to follow
 *		Alan Cox	:	Removed incorrect check for 20 * psh
 *	Michael O'Reilly	:	ack < copied bug fix.
 *	Johannes Stille		:	Misc tcp fixes (not all in yet).
 *		Alan Cox	:	FIN with no memory -> CRASH
 *		Alan Cox	:	Added socket option proto entries.
 *					Also added awareness of them to accept.
 *		Alan Cox	:	Added TCP options (SOL_TCP)
 *		Alan Cox	:	Switched wakeup calls to callbacks,
 *					so the kernel can layer network
 *					sockets.
 *		Alan Cox	:	Use ip_tos/ip_ttl settings.
 *		Alan Cox	:	Handle FIN (more) properly (we hope).
 *		Alan Cox	:	RST frames sent on unsynchronised
 *					state ack error.
 *		Alan Cox	:	Put in missing check for SYN bit.
 *		Alan Cox	:	Added tcp_select_window() aka NET2E
 *					window non shrink trick.
 *		Alan Cox	:	Added a couple of small NET2E timer
 *					fixes
 *		Charles Hedrick :	TCP fixes
 *		Toomas Tamm	:	TCP window fixes
 *		Alan Cox	:	Small URG fix to rlogin ^C ack fight
 *		Charles Hedrick	:	Rewrote most of it to actually work
 *		Linus		:	Rewrote tcp_read() and URG handling
 *					completely
 *		Gerhard Koerting:	Fixed some missing timer handling
 *		Matthew Dillon  :	Reworked TCP machine states as per RFC
 *		Gerhard Koerting:	PC/TCP workarounds
 *		Adam Caldwell	:	Assorted timer/timing errors
 *		Matthew Dillon	:	Fixed another RST bug
 *		Alan Cox	:	Move to kernel side addressing changes.
 *		Alan Cox	:	Beginning work on TCP fastpathing
 *					(not yet usable)
 *		Arnt Gulbrandsen:	Turbocharged tcp_check() routine.
 *		Alan Cox	:	TCP fast path debugging
 *		Alan Cox	:	Window clamping
 *		Michael Riepe	:	Bug in tcp_check()
 *		Matt Dillon	:	More TCP improvements and RST bug fixes
 *		Matt Dillon	:	Yet more small nasties remove from the
 *					TCP code (Be very nice to this man if
 *					tcp finally works 100%) 8)
 *		Alan Cox	:	BSD accept semantics.
 *		Alan Cox	:	Reset on closedown bug.
 *	Peter De Schrijver	:	ENOTCONN check missing in tcp_sendto().
 *		Michael Pall	:	Handle poll() after URG properly in
 *					all cases.
 *		Michael Pall	:	Undo the last fix in tcp_read_urg()
 *					(multi URG PUSH broke rlogin).
 *		Michael Pall	:	Fix the multi URG PUSH problem in
 *					tcp_readable(), poll() after URG
 *					works now.
 *		Michael Pall	:	recv(...,MSG_OOB) never blocks in the
 *					BSD api.
 *		Alan Cox	:	Changed the semantics of sk->socket to
 *					fix a race and a signal problem with
 *					accept() and async I/O.
 *		Alan Cox	:	Relaxed the rules on tcp_sendto().
 *		Yury Shevchuk	:	Really fixed accept() blocking problem.
 *		Craig I. Hagan  :	Allow for BSD compatible TIME_WAIT for
 *					clients/servers which listen in on
 *					fixed ports.
 *		Alan Cox	:	Cleaned the above up and shrank it to
 *					a sensible code size.
 *		Alan Cox	:	Self connect lockup fix.
 *		Alan Cox	:	No connect to multicast.
 *		Ross Biro	:	Close unaccepted children on master
 *					socket close.
 *		Alan Cox	:	Reset tracing code.
 *		Alan Cox	:	Spurious resets on shutdown.
 *		Alan Cox	:	Giant 15 minute/60 second timer error
 *		Alan Cox	:	Small whoops in polling before an
 *					accept.
 *		Alan Cox	:	Kept the state trace facility since
 *					it's handy for debugging.
 *		Alan Cox	:	More reset handler fixes.
 *		Alan Cox	:	Started rewriting the code based on
 *					the RFC's for other useful protocol
 *					references see: Comer, KA9Q NOS, and
 *					for a reference on the difference
 *					between specifications and how BSD
 *					works see the 4.4lite source.
 *		A.N.Kuznetsov	:	Don't time wait on completion of tidy
 *					close.
 *		Linus Torvalds	:	Fin/Shutdown & copied_seq changes.
 *		Linus Torvalds	:	Fixed BSD port reuse to work first syn
 *		Alan Cox	:	Reimplemented timers as per the RFC
 *					and using multiple timers for sanity.
 *		Alan Cox	:	Small bug fixes, and a lot of new
 *					comments.
 *		Alan Cox	:	Fixed dual reader crash by locking
 *					the buffers (much like datagram.c)
 *		Alan Cox	:	Fixed stuck sockets in probe. A probe
 *					now gets fed up of retrying without
 *					(even a no space) answer.
 *		Alan Cox	:	Extracted closing code better
 *		Alan Cox	:	Fixed the closing state machine to
 *					resemble the RFC.
 *		Alan Cox	:	More 'per spec' fixes.
 *		Jorge Cwik	:	Even faster checksumming.
 *		Alan Cox	:	tcp_data() doesn't ack illegal PSH
 *					only frames. At least one pc tcp stack
 *					generates them.
 *		Alan Cox	:	Cache last socket.
 *		Alan Cox	:	Per route irtt.
 *		Matt Day	:	poll()->select() match BSD precisely on error
 *		Alan Cox	:	New buffers
 *		Marc Tamsky	:	Various sk->prot->retransmits and
 *					sk->retransmits misupdating fixed.
 *					Fixed tcp_write_timeout: stuck close,
 *					and TCP syn retries gets used now.
 *		Mark Yarvis	:	In tcp_read_wakeup(), don't send an
 *					ack if state is TCP_CLOSED.
 *		Alan Cox	:	Look up device on a retransmit - routes may
 *					change. Doesn't yet cope with MSS shrink right
 *					but it's a start!
 *		Marc Tamsky	:	Closing in closing fixes.
 *		Mike Shaver	:	RFC1122 verifications.
 *		Alan Cox	:	rcv_saddr errors.
 *		Alan Cox	:	Block double connect().
 *		Alan Cox	:	Small hooks for enSKIP.
 *		Alexey Kuznetsov:	Path MTU discovery.
 *		Alan Cox	:	Support soft errors.
 *		Alan Cox	:	Fix MTU discovery pathological case
 *					when the remote claims no mtu!
 *		Marc Tamsky	:	TCP_CLOSE fix.
 *		Colin (G3TNE)	:	Send a reset on syn ack replies in
 *					window but wrong (fixes NT lpd problems)
 *		Pedro Roque	:	Better TCP window handling, delayed ack.
 *		Joerg Reuter	:	No modification of locked buffers in
 *					tcp_do_retransmit()
 *		Eric Schenk	:	Changed receiver side silly window
 *					avoidance algorithm to BSD style
 *					algorithm. This doubles throughput
 *					against machines running Solaris,
 *					and seems to result in general
 *					improvement.
 *	Stefan Magdalinski	:	adjusted tcp_readable() to fix FIONREAD
 *	Willy Konynenberg	:	Transparent proxying support.
 *	Mike McLagan		:	Routing by source
 *		Keith Owens	:	Do proper merging with partial SKB's in
 *					tcp_do_sendmsg to avoid burstiness.
 *		Eric Schenk	:	Fix fast close down bug with
 *					shutdown() followed by close().
 *		Andi Kleen 	:	Make poll agree with SIGIO
 *	Salvatore Sanfilippo	:	Support SO_LINGER with linger == 1 and
 *					lingertime == 0 (RFC 793 ABORT Call)
 *	Hirokazu Takahashi	:	Use copy_from_user() instead of
 *					csum_and_copy_from_user() if possible.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or(at your option) any later version.
 *
 * Description of States:
 *
 *	TCP_SYN_SENT		sent a connection request, waiting for ack
 *
 *	TCP_SYN_RECV		received a connection request, sent ack,
 *				waiting for final ack in three-way handshake.
 *
 *	TCP_ESTABLISHED		connection established
 *
 *	TCP_FIN_WAIT1		our side has shutdown, waiting to complete
 *				transmission of remaining buffered data
 *
 *	TCP_FIN_WAIT2		all buffered data sent, waiting for remote
 *				to shutdown
 *
 *	TCP_CLOSING		both sides have shutdown but we still have
 *				data we have to finish sending
 *
 *	TCP_TIME_WAIT		timeout to catch resent junk before entering
 *				closed, can only be entered from FIN_WAIT2
 *				or CLOSING.  Required because the other end
 *				may not have gotten our last ACK causing it
 *				to retransmit the data packet (which we ignore)
 *
 *	TCP_CLOSE_WAIT		remote side has shutdown and is waiting for
 *				us to finish writing our data and to shutdown
 *				(we have to close() to move on to LAST_ACK)
 *
 *	TCP_LAST_ACK		out side has shutdown after remote has
 *				shutdown.  There may still be data in our
 *				buffer that we have to finish sending
 *
 *	TCP_CLOSE		socket is finished
 */

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#define pr_fmt(fmt) "TCP: " fmt

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#include <crypto/hash.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
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#include <linux/inet_diag.h>
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#include <linux/init.h>
#include <linux/fs.h>
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#include <linux/skbuff.h>
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#include <linux/scatterlist.h>
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#include <linux/splice.h>
#include <linux/net.h>
#include <linux/socket.h>
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#include <linux/random.h>
#include <linux/bootmem.h>
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#include <linux/highmem.h>
#include <linux/swap.h>
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#include <linux/cache.h>
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#include <linux/err.h>
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#include <linux/time.h>
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#include <linux/slab.h>
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#include <linux/errqueue.h>
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#include <linux/static_key.h>
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#include <net/icmp.h>
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#include <net/inet_common.h>
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#include <net/tcp.h>
#include <net/xfrm.h>
#include <net/ip.h>
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#include <net/sock.h>
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#include <linux/uaccess.h>
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#include <asm/ioctls.h>
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#include <net/busy_poll.h>
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struct percpu_counter tcp_orphan_count;
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EXPORT_SYMBOL_GPL(tcp_orphan_count);

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long sysctl_tcp_mem[3] __read_mostly;
EXPORT_SYMBOL(sysctl_tcp_mem);
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atomic_long_t tcp_memory_allocated;	/* Current allocated memory. */
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EXPORT_SYMBOL(tcp_memory_allocated);
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#if IS_ENABLED(CONFIG_SMC)
DEFINE_STATIC_KEY_FALSE(tcp_have_smc);
EXPORT_SYMBOL(tcp_have_smc);
#endif

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/*
 * Current number of TCP sockets.
 */
struct percpu_counter tcp_sockets_allocated;
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EXPORT_SYMBOL(tcp_sockets_allocated);

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/*
 * TCP splice context
 */
struct tcp_splice_state {
	struct pipe_inode_info *pipe;
	size_t len;
	unsigned int flags;
};

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/*
 * Pressure flag: try to collapse.
 * Technical note: it is used by multiple contexts non atomically.
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 * All the __sk_mem_schedule() is of this nature: accounting
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 * is strict, actions are advisory and have some latency.
 */
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unsigned long tcp_memory_pressure __read_mostly;
EXPORT_SYMBOL_GPL(tcp_memory_pressure);
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void tcp_enter_memory_pressure(struct sock *sk)
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{
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	unsigned long val;

	if (tcp_memory_pressure)
		return;
	val = jiffies;

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

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

	if (!tcp_memory_pressure)
		return;
	val = xchg(&tcp_memory_pressure, 0);
	if (val)
		NET_ADD_STATS(sock_net(sk), LINUX_MIB_TCPMEMORYPRESSURESCHRONO,
			      jiffies_to_msecs(jiffies - val));
}
EXPORT_SYMBOL_GPL(tcp_leave_memory_pressure);
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/* Convert seconds to retransmits based on initial and max timeout */
static u8 secs_to_retrans(int seconds, int timeout, int rto_max)
{
	u8 res = 0;

	if (seconds > 0) {
		int period = timeout;

		res = 1;
		while (seconds > period && res < 255) {
			res++;
			timeout <<= 1;
			if (timeout > rto_max)
				timeout = rto_max;
			period += timeout;
		}
	}
	return res;
}

/* Convert retransmits to seconds based on initial and max timeout */
static int retrans_to_secs(u8 retrans, int timeout, int rto_max)
{
	int period = 0;

	if (retrans > 0) {
		period = timeout;
		while (--retrans) {
			timeout <<= 1;
			if (timeout > rto_max)
				timeout = rto_max;
			period += timeout;
		}
	}
	return period;
}

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static u64 tcp_compute_delivery_rate(const struct tcp_sock *tp)
{
	u32 rate = READ_ONCE(tp->rate_delivered);
	u32 intv = READ_ONCE(tp->rate_interval_us);
	u64 rate64 = 0;

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

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/* Address-family independent initialization for a tcp_sock.
 *
 * NOTE: A lot of things set to zero explicitly by call to
 *       sk_alloc() so need not be done here.
 */
void tcp_init_sock(struct sock *sk)
{
	struct inet_connection_sock *icsk = inet_csk(sk);
	struct tcp_sock *tp = tcp_sk(sk);

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	tp->out_of_order_queue = RB_ROOT;
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	sk->tcp_rtx_queue = RB_ROOT;
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	tcp_init_xmit_timers(sk);
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	INIT_LIST_HEAD(&tp->tsq_node);
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	INIT_LIST_HEAD(&tp->tsorted_sent_queue);
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	icsk->icsk_rto = TCP_TIMEOUT_INIT;
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	tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
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	minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U);
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	/* So many TCP implementations out there (incorrectly) count the
	 * initial SYN frame in their delayed-ACK and congestion control
	 * algorithms that we must have the following bandaid to talk
	 * efficiently to them.  -DaveM
	 */
	tp->snd_cwnd = TCP_INIT_CWND;

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	/* There's a bubble in the pipe until at least the first ACK. */
	tp->app_limited = ~0U;

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	/* See draft-stevens-tcpca-spec-01 for discussion of the
	 * initialization of these values.
	 */
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
	tp->snd_cwnd_clamp = ~0;
	tp->mss_cache = TCP_MSS_DEFAULT;

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	tp->reordering = sock_net(sk)->ipv4.sysctl_tcp_reordering;
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	tcp_assign_congestion_control(sk);
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	tp->tsoffset = 0;
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	tp->rack.reo_wnd_steps = 1;
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	sk->sk_state = TCP_CLOSE;

	sk->sk_write_space = sk_stream_write_space;
	sock_set_flag(sk, SOCK_USE_WRITE_QUEUE);

	icsk->icsk_sync_mss = tcp_sync_mss;

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	sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1];
	sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1];
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	sk_sockets_allocated_inc(sk);
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	sk->sk_route_forced_caps = NETIF_F_GSO;
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}
EXPORT_SYMBOL(tcp_init_sock);

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void tcp_init_transfer(struct sock *sk, int bpf_op)
{
	struct inet_connection_sock *icsk = inet_csk(sk);

	tcp_mtup_init(sk);
	icsk->icsk_af_ops->rebuild_header(sk);
	tcp_init_metrics(sk);
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	tcp_call_bpf(sk, bpf_op, 0, NULL);
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	tcp_init_congestion_control(sk);
	tcp_init_buffer_space(sk);
}

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

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	if (tsflags && skb) {
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		struct skb_shared_info *shinfo = skb_shinfo(skb);
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		struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
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		sock_tx_timestamp(sk, tsflags, &shinfo->tx_flags);
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		if (tsflags & SOF_TIMESTAMPING_TX_ACK)
			tcb->txstamp_ack = 1;
		if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
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			shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1;
	}
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}

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static inline bool tcp_stream_is_readable(const struct tcp_sock *tp,
					  int target, struct sock *sk)
{
	return (tp->rcv_nxt - tp->copied_seq >= target) ||
		(sk->sk_prot->stream_memory_read ?
		sk->sk_prot->stream_memory_read(sk) : false);
}

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/*
 *	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()
539
	 * in state CLOSE_WAIT. One solution is evident --- to set EPOLLHUP
L
Linus Torvalds 已提交
540 541
	 * if and only if shutdown has been made in both directions.
	 * Actually, it is interesting to look how Solaris and DUX
542
	 * solve this dilemma. I would prefer, if EPOLLHUP were maskable,
L
Linus Torvalds 已提交
543 544
	 * then we could set it on SND_SHUTDOWN. BTW examples given
	 * in Stevens' books assume exactly this behaviour, it explains
545
	 * why EPOLLHUP is incompatible with EPOLLOUT.	--ANK
L
Linus Torvalds 已提交
546 547 548 549
	 *
	 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
	 * blocking on fresh not-connected or disconnected socket. --ANK
	 */
550
	if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
551
		mask |= EPOLLHUP;
L
Linus Torvalds 已提交
552
	if (sk->sk_shutdown & RCV_SHUTDOWN)
553
		mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
L
Linus Torvalds 已提交
554

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

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

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

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

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

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

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

int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
	struct tcp_sock *tp = tcp_sk(sk);
	int answ;
E
Eric Dumazet 已提交
609
	bool slow;
L
Linus Torvalds 已提交
610 611 612 613 614 615

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

E
Eric Dumazet 已提交
616
		slow = lock_sock_fast(sk);
617
		answ = tcp_inq(sk);
E
Eric Dumazet 已提交
618
		unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
619 620 621 622 623 624 625 626 627 628 629 630 631
		break;
	case SIOCATMARK:
		answ = tp->urg_data && tp->urg_seq == tp->copied_seq;
		break;
	case SIOCOUTQ:
		if (sk->sk_state == TCP_LISTEN)
			return -EINVAL;

		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
			answ = 0;
		else
			answ = tp->write_seq - tp->snd_una;
		break;
632 633 634 635 636 637 638 639 640
	case SIOCOUTQNSD:
		if (sk->sk_state == TCP_LISTEN)
			return -EINVAL;

		if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV))
			answ = 0;
		else
			answ = tp->write_seq - tp->snd_nxt;
		break;
L
Linus Torvalds 已提交
641 642
	default:
		return -ENOIOCTLCMD;
643
	}
L
Linus Torvalds 已提交
644 645 646

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

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

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

660
static void skb_entail(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
661
{
662
	struct tcp_sock *tp = tcp_sk(sk);
663 664 665 666
	struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);

	skb->csum    = 0;
	tcb->seq     = tcb->end_seq = tp->write_seq;
E
Eric Dumazet 已提交
667
	tcb->tcp_flags = TCPHDR_ACK;
668
	tcb->sacked  = 0;
669
	__skb_header_release(skb);
670
	tcp_add_write_queue_tail(sk, skb);
671 672
	sk->sk_wmem_queued += skb->truesize;
	sk_mem_charge(sk, skb->truesize);
673
	if (tp->nonagle & TCP_NAGLE_PUSH)
674
		tp->nonagle &= ~TCP_NAGLE_PUSH;
675 676

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

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

E
Eric Dumazet 已提交
685
/* If a not yet filled skb is pushed, do not send it if
686
 * we have data packets in Qdisc or NIC queues :
E
Eric Dumazet 已提交
687 688 689 690
 * Because TX completion will happen shortly, it gives a chance
 * to coalesce future sendmsg() payload into this skb, without
 * need for a timer, and with no latency trade off.
 * As packets containing data payload have a bigger truesize
691 692 693
 * than pure acks (dataless) packets, the last checks prevent
 * autocorking if we only have an ACK in Qdisc/NIC queues,
 * or if TX completion was delayed after we processed ACK packet.
E
Eric Dumazet 已提交
694 695 696
 */
static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
				int size_goal)
L
Linus Torvalds 已提交
697
{
E
Eric Dumazet 已提交
698
	return skb->len < size_goal &&
699
	       sock_net(sk)->ipv4.sysctl_tcp_autocorking &&
700
	       skb != tcp_write_queue_head(sk) &&
701
	       refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
E
Eric Dumazet 已提交
702 703 704 705 706 707 708
}

static void tcp_push(struct sock *sk, int flags, int mss_now,
		     int nonagle, int size_goal)
{
	struct tcp_sock *tp = tcp_sk(sk);
	struct sk_buff *skb;
709

E
Eric Dumazet 已提交
710
	skb = tcp_write_queue_tail(sk);
711 712
	if (!skb)
		return;
E
Eric Dumazet 已提交
713 714 715 716 717 718 719 720
	if (!(flags & MSG_MORE) || forced_push(tp))
		tcp_mark_push(tp, skb);

	tcp_mark_urg(tp, flags);

	if (tcp_should_autocork(sk, skb, size_goal)) {

		/* avoid atomic op if TSQ_THROTTLED bit is already set */
721
		if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
E
Eric Dumazet 已提交
722
			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
723
			set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
E
Eric Dumazet 已提交
724
		}
725 726 727
		/* It is possible TX completion already happened
		 * before we set TSQ_THROTTLED.
		 */
728
		if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
729
			return;
L
Linus Torvalds 已提交
730
	}
E
Eric Dumazet 已提交
731 732 733 734 735

	if (flags & MSG_MORE)
		nonagle = TCP_NAGLE_CORK;

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

738 739
static int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
				unsigned int offset, size_t len)
J
Jens Axboe 已提交
740 741
{
	struct tcp_splice_state *tss = rd_desc->arg.data;
742
	int ret;
J
Jens Axboe 已提交
743

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

static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
{
	/* Store TCP splice context information in read_descriptor_t. */
	read_descriptor_t rd_desc = {
		.arg.data = tss,
756
		.count	  = tss->len,
J
Jens Axboe 已提交
757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787
	};

	return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
}

/**
 *  tcp_splice_read - splice data from TCP socket to a pipe
 * @sock:	socket to splice from
 * @ppos:	position (not valid)
 * @pipe:	pipe to splice to
 * @len:	number of bytes to splice
 * @flags:	splice modifier flags
 *
 * Description:
 *    Will read pages from given socket and fill them into a pipe.
 *
 **/
ssize_t tcp_splice_read(struct socket *sock, loff_t *ppos,
			struct pipe_inode_info *pipe, size_t len,
			unsigned int flags)
{
	struct sock *sk = sock->sk;
	struct tcp_splice_state tss = {
		.pipe = pipe,
		.len = len,
		.flags = flags,
	};
	long timeo;
	ssize_t spliced;
	int ret;

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

	ret = spliced = 0;

	lock_sock(sk);

799
	timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
J
Jens Axboe 已提交
800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827
	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;
			}
828 829 830 831 832 833
			/* 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;
834
			sk_wait_data(sk, &timeo, NULL);
J
Jens Axboe 已提交
835 836 837 838 839 840 841 842 843
			if (signal_pending(current)) {
				ret = sock_intr_errno(timeo);
				break;
			}
			continue;
		}
		tss.len -= ret;
		spliced += ret;

844 845
		if (!timeo)
			break;
J
Jens Axboe 已提交
846 847 848 849
		release_sock(sk);
		lock_sock(sk);

		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
850
		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
J
Jens Axboe 已提交
851 852 853 854 855 856 857 858 859 860 861
		    signal_pending(current))
			break;
	}

	release_sock(sk);

	if (spliced)
		return spliced;

	return ret;
}
E
Eric Dumazet 已提交
862
EXPORT_SYMBOL(tcp_splice_read);
J
Jens Axboe 已提交
863

864 865
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
				    bool force_schedule)
866 867 868 869 870 871
{
	struct sk_buff *skb;

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

872 873 874
	if (unlikely(tcp_under_memory_pressure(sk)))
		sk_mem_reclaim_partial(sk);

875
	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
876
	if (likely(skb)) {
877
		bool mem_scheduled;
878

879 880
		if (force_schedule) {
			mem_scheduled = true;
881 882
			sk_forced_mem_schedule(sk, skb->truesize);
		} else {
883
			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
884
		}
885
		if (likely(mem_scheduled)) {
886
			skb_reserve(skb, sk->sk_prot->max_header);
887 888 889 890
			/*
			 * Make sure that we have exactly size bytes
			 * available to the caller, no more, no less.
			 */
E
Eric Dumazet 已提交
891
			skb->reserved_tailroom = skb->end - skb->tail - size;
892
			INIT_LIST_HEAD(&skb->tcp_tsorted_anchor);
893 894 895 896
			return skb;
		}
		__kfree_skb(skb);
	} else {
897
		sk->sk_prot->enter_memory_pressure(sk);
898 899 900 901 902
		sk_stream_moderate_sndbuf(sk);
	}
	return NULL;
}

I
Ilpo Järvinen 已提交
903 904 905 906
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
				       int large_allowed)
{
	struct tcp_sock *tp = tcp_sk(sk);
907
	u32 new_size_goal, size_goal;
E
Eric Dumazet 已提交
908

E
Eric Dumazet 已提交
909
	if (!large_allowed)
E
Eric Dumazet 已提交
910 911
		return mss_now;

912 913
	/* 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
914 915 916 917 918 919 920 921 922
	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
923 924
	}

E
Eric Dumazet 已提交
925
	return max(size_goal, mss_now);
I
Ilpo Järvinen 已提交
926 927 928 929 930 931 932 933 934 935 936 937
}

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;
}

938 939
ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
			 size_t size, int flags)
L
Linus Torvalds 已提交
940 941
{
	struct tcp_sock *tp = tcp_sk(sk);
942
	int mss_now, size_goal;
L
Linus Torvalds 已提交
943 944 945 946
	int err;
	ssize_t copied;
	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

947 948 949 950 951 952
	/* 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)) {
953 954
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
955
			goto out_err;
956
	}
L
Linus Torvalds 已提交
957

958
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
959

I
Ilpo Järvinen 已提交
960
	mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
961 962 963 964
	copied = 0;

	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
965
		goto out_err;
L
Linus Torvalds 已提交
966

967
	while (size > 0) {
968
		struct sk_buff *skb = tcp_write_queue_tail(sk);
969 970
		int copy, i;
		bool can_coalesce;
L
Linus Torvalds 已提交
971

972
		if (!skb || (copy = size_goal - skb->len) <= 0 ||
973
		    !tcp_skb_can_collapse_to(skb)) {
L
Linus Torvalds 已提交
974 975 976 977
new_segment:
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;

978
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
979
					tcp_rtx_and_write_queues_empty(sk));
L
Linus Torvalds 已提交
980 981 982
			if (!skb)
				goto wait_for_memory;

983
			skb_entail(sk, skb);
984
			copy = size_goal;
L
Linus Torvalds 已提交
985 986 987 988 989 990 991
		}

		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
992
		if (!can_coalesce && i >= sysctl_max_skb_frags) {
L
Linus Torvalds 已提交
993 994 995
			tcp_mark_push(tp, skb);
			goto new_segment;
		}
996
		if (!sk_wmem_schedule(sk, copy))
L
Linus Torvalds 已提交
997
			goto wait_for_memory;
998

L
Linus Torvalds 已提交
999
		if (can_coalesce) {
E
Eric Dumazet 已提交
1000
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
L
Linus Torvalds 已提交
1001 1002 1003 1004
		} else {
			get_page(page);
			skb_fill_page_desc(skb, i, page, offset, copy);
		}
1005 1006 1007

		if (!(flags & MSG_NO_SHARED_FRAGS))
			skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
1008

L
Linus Torvalds 已提交
1009 1010 1011 1012
		skb->len += copy;
		skb->data_len += copy;
		skb->truesize += copy;
		sk->sk_wmem_queued += copy;
1013
		sk_mem_charge(sk, copy);
1014
		skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1015 1016
		tp->write_seq += copy;
		TCP_SKB_CB(skb)->end_seq += copy;
1017
		tcp_skb_pcount_set(skb, 0);
L
Linus Torvalds 已提交
1018 1019

		if (!copied)
E
Eric Dumazet 已提交
1020
			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
L
Linus Torvalds 已提交
1021 1022

		copied += copy;
1023
		offset += copy;
1024
		size -= copy;
1025
		if (!size)
L
Linus Torvalds 已提交
1026 1027
			goto out;

1028
		if (skb->len < size_goal || (flags & MSG_OOB))
L
Linus Torvalds 已提交
1029 1030 1031 1032
			continue;

		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
1033
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1034
		} else if (skb == tcp_send_head(sk))
L
Linus Torvalds 已提交
1035 1036 1037 1038 1039 1040
			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
1041 1042
		tcp_push(sk, flags & ~MSG_MORE, mss_now,
			 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1043

1044 1045
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
1046 1047
			goto do_error;

I
Ilpo Järvinen 已提交
1048
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1049 1050 1051
	}

out:
1052
	if (copied) {
E
Eric Dumazet 已提交
1053
		tcp_tx_timestamp(sk, sk->sk_tsflags);
1054 1055 1056
		if (!(flags & MSG_SENDPAGE_NOTLAST))
			tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
	}
L
Linus Torvalds 已提交
1057 1058 1059 1060 1061 1062
	return copied;

do_error:
	if (copied)
		goto out;
out_err:
1063
	/* make sure we wake any epoll edge trigger waiter */
1064 1065
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1066
		sk->sk_write_space(sk);
1067 1068
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1069 1070
	return sk_stream_error(sk, flags, err);
}
1071
EXPORT_SYMBOL_GPL(do_tcp_sendpages);
L
Linus Torvalds 已提交
1072

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

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

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

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

	lock_sock(sk);
	ret = tcp_sendpage_locked(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1092
	release_sock(sk);
1093 1094

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

1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114
/* 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
1115
static int select_size(bool first_skb, bool zc)
L
Linus Torvalds 已提交
1116
{
E
Eric Dumazet 已提交
1117 1118 1119
	if (zc)
		return 0;
	return linear_payload_sz(first_skb);
L
Linus Torvalds 已提交
1120 1121
}

1122 1123
void tcp_free_fastopen_req(struct tcp_sock *tp)
{
1124
	if (tp->fastopen_req) {
1125 1126 1127 1128 1129
		kfree(tp->fastopen_req);
		tp->fastopen_req = NULL;
	}
}

1130 1131
static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
				int *copied, size_t size)
1132 1133
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Wei Wang 已提交
1134
	struct inet_sock *inet = inet_sk(sk);
1135
	struct sockaddr *uaddr = msg->msg_name;
1136 1137
	int err, flags;

1138
	if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
1139 1140
	    (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
	     uaddr->sa_family == AF_UNSPEC))
1141
		return -EOPNOTSUPP;
1142
	if (tp->fastopen_req)
1143 1144 1145 1146
		return -EALREADY; /* Another Fast Open is in progress */

	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
				   sk->sk_allocation);
1147
	if (unlikely(!tp->fastopen_req))
1148 1149
		return -ENOBUFS;
	tp->fastopen_req->data = msg;
1150
	tp->fastopen_req->size = size;
1151

W
Wei Wang 已提交
1152 1153 1154 1155 1156 1157 1158 1159 1160
	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;
		}
	}
1161
	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1162
	err = __inet_stream_connect(sk->sk_socket, uaddr,
1163
				    msg->msg_namelen, flags, 1);
1164 1165 1166 1167 1168 1169 1170 1171
	/* 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;
	}
1172 1173 1174
	return err;
}

1175
int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
L
Linus Torvalds 已提交
1176 1177
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Willem de Bruijn 已提交
1178
	struct ubuf_info *uarg = NULL;
L
Linus Torvalds 已提交
1179
	struct sk_buff *skb;
1180
	struct sockcm_cookie sockc;
1181 1182
	int flags, err, copied = 0;
	int mss_now = 0, size_goal, copied_syn = 0;
1183
	bool process_backlog = false;
E
Eric Dumazet 已提交
1184
	bool zc = false;
L
Linus Torvalds 已提交
1185 1186 1187
	long timeo;

	flags = msg->msg_flags;
W
Willem de Bruijn 已提交
1188 1189 1190 1191 1192 1193 1194

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

1195
		skb = tcp_write_queue_tail(sk);
W
Willem de Bruijn 已提交
1196 1197 1198 1199 1200 1201
		uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb));
		if (!uarg) {
			err = -ENOBUFS;
			goto out_err;
		}

E
Eric Dumazet 已提交
1202
		zc = sk->sk_route_caps & NETIF_F_SG;
1203
		if (!zc)
W
Willem de Bruijn 已提交
1204 1205 1206
			uarg->zerocopy = 0;
	}

1207 1208
	if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect) &&
	    !tp->repair) {
1209
		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1210 1211 1212 1213 1214 1215
		if (err == -EINPROGRESS && copied_syn > 0)
			goto out;
		else if (err)
			goto out_err;
	}

L
Linus Torvalds 已提交
1216 1217
	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

1218 1219
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1220 1221 1222 1223 1224 1225
	/* 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)) {
1226 1227
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
1228
			goto do_error;
1229
	}
L
Linus Torvalds 已提交
1230

P
Pavel Emelyanov 已提交
1231 1232 1233
	if (unlikely(tp->repair)) {
		if (tp->repair_queue == TCP_RECV_QUEUE) {
			copied = tcp_send_rcvq(sk, msg, size);
1234
			goto out_nopush;
P
Pavel Emelyanov 已提交
1235 1236 1237 1238 1239 1240 1241 1242 1243
		}

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

		/* 'common' sending to sendq */
	}

1244 1245 1246 1247 1248 1249 1250 1251 1252
	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
1253
	/* This should be in poll */
1254
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
1255 1256 1257 1258

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

1259 1260 1261
restart:
	mss_now = tcp_send_mss(sk, &size_goal, flags);

L
Linus Torvalds 已提交
1262 1263
	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1264
		goto do_error;
L
Linus Torvalds 已提交
1265

A
Al Viro 已提交
1266
	while (msg_data_left(msg)) {
1267
		int copy = 0;
L
Linus Torvalds 已提交
1268

1269
		skb = tcp_write_queue_tail(sk);
1270 1271
		if (skb)
			copy = size_goal - skb->len;
L
Linus Torvalds 已提交
1272

1273
		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1274
			bool first_skb;
1275
			int linear;
1276

L
Linus Torvalds 已提交
1277
new_segment:
1278 1279 1280 1281 1282
			/* 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
1283

1284 1285
			if (process_backlog && sk_flush_backlog(sk)) {
				process_backlog = false;
1286
				goto restart;
1287
			}
1288
			first_skb = tcp_rtx_and_write_queues_empty(sk);
E
Eric Dumazet 已提交
1289
			linear = select_size(first_skb, zc);
1290
			skb = sk_stream_alloc_skb(sk, linear, sk->sk_allocation,
1291
						  first_skb);
1292 1293
			if (!skb)
				goto wait_for_memory;
L
Linus Torvalds 已提交
1294

1295
			process_backlog = true;
E
Eric Dumazet 已提交
1296
			skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1297

1298 1299
			skb_entail(sk, skb);
			copy = size_goal;
1300

1301 1302 1303 1304 1305 1306 1307
			/* 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
1308

1309
		/* Try to append data to the end of skb. */
A
Al Viro 已提交
1310 1311
		if (copy > msg_data_left(msg))
			copy = msg_data_left(msg);
1312 1313

		/* Where to copy to? */
1314
		if (skb_availroom(skb) > 0 && !zc) {
1315 1316 1317 1318 1319
			/* 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;
1320
		} else if (!zc) {
1321 1322 1323 1324 1325 1326
			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;
1327

1328 1329
			if (!skb_can_coalesce(skb, i, pfrag->page,
					      pfrag->offset)) {
E
Eric Dumazet 已提交
1330
				if (i >= sysctl_max_skb_frags) {
1331 1332
					tcp_mark_push(tp, skb);
					goto new_segment;
L
Linus Torvalds 已提交
1333
				}
1334
				merge = false;
L
Linus Torvalds 已提交
1335 1336
			}

1337 1338 1339 1340
			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
1341

1342 1343 1344 1345 1346 1347
			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
1348

1349 1350 1351 1352 1353 1354
			/* 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);
1355
				page_ref_inc(pfrag->page);
1356
			}
1357
			pfrag->offset += copy;
W
Willem de Bruijn 已提交
1358 1359
		} else {
			err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
W
Willem de Bruijn 已提交
1360 1361
			if (err == -EMSGSIZE || err == -EEXIST) {
				tcp_mark_push(tp, skb);
W
Willem de Bruijn 已提交
1362
				goto new_segment;
W
Willem de Bruijn 已提交
1363
			}
W
Willem de Bruijn 已提交
1364 1365 1366
			if (err < 0)
				goto do_error;
			copy = err;
1367 1368 1369 1370 1371 1372 1373 1374
		}

		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
1375

1376
		copied += copy;
A
Al Viro 已提交
1377
		if (!msg_data_left(msg)) {
1378 1379
			if (unlikely(flags & MSG_EOR))
				TCP_SKB_CB(skb)->eor = 1;
1380 1381
			goto out;
		}
L
Linus Torvalds 已提交
1382

1383
		if (skb->len < size_goal || (flags & MSG_OOB) || unlikely(tp->repair))
L
Linus Torvalds 已提交
1384 1385
			continue;

1386 1387 1388 1389 1390 1391 1392
		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
1393
wait_for_sndbuf:
1394
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
L
Linus Torvalds 已提交
1395
wait_for_memory:
1396 1397 1398
		if (copied)
			tcp_push(sk, flags & ~MSG_MORE, mss_now,
				 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1399

1400 1401
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
1402
			goto do_error;
L
Linus Torvalds 已提交
1403

1404
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1405 1406 1407
	}

out:
1408
	if (copied) {
E
Eric Dumazet 已提交
1409
		tcp_tx_timestamp(sk, sockc.tsflags);
E
Eric Dumazet 已提交
1410
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1411
	}
1412
out_nopush:
W
Willem de Bruijn 已提交
1413
	sock_zerocopy_put(uarg);
1414
	return copied + copied_syn;
L
Linus Torvalds 已提交
1415 1416 1417

do_fault:
	if (!skb->len) {
1418 1419 1420 1421 1422
		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);
1423
		sk_wmem_free_skb(sk, skb);
L
Linus Torvalds 已提交
1424 1425 1426
	}

do_error:
1427
	if (copied + copied_syn)
L
Linus Torvalds 已提交
1428 1429
		goto out;
out_err:
W
Willem de Bruijn 已提交
1430
	sock_zerocopy_put_abort(uarg);
L
Linus Torvalds 已提交
1431
	err = sk_stream_error(sk, flags, err);
1432
	/* make sure we wake any epoll edge trigger waiter */
1433 1434
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1435
		sk->sk_write_space(sk);
1436 1437
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1438 1439
	return err;
}
1440
EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451

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
1452
EXPORT_SYMBOL(tcp_sendmsg);
L
Linus Torvalds 已提交
1453 1454 1455 1456 1457 1458

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

1459
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
L
Linus Torvalds 已提交
1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482
{
	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
1483
				err = memcpy_to_msg(msg, &c, 1);
L
Linus Torvalds 已提交
1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502
			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
1503 1504 1505 1506 1507 1508 1509
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 */

1510 1511 1512 1513 1514 1515 1516
	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
1517
	skb_queue_walk(&sk->sk_write_queue, skb) {
1518
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
P
Pavel Emelyanov 已提交
1519 1520 1521 1522 1523 1524 1525 1526 1527
		if (err)
			break;

		copied += skb->len;
	}

	return err ?: copied;
}

L
Linus Torvalds 已提交
1528 1529 1530 1531 1532 1533
/* 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.
 */
1534
static void tcp_cleanup_rbuf(struct sock *sk, int copied)
L
Linus Torvalds 已提交
1535 1536
{
	struct tcp_sock *tp = tcp_sk(sk);
E
Eric Dumazet 已提交
1537
	bool time_to_ack = false;
L
Linus Torvalds 已提交
1538 1539 1540

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

1541
	WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
J
Joe Perches 已提交
1542
	     "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1543
	     tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
L
Linus Torvalds 已提交
1544

1545 1546
	if (inet_csk_ack_scheduled(sk)) {
		const struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1547 1548
		   /* Delayed ACKs frequently hit locked sockets during bulk
		    * receive. */
1549
		if (icsk->icsk_ack.blocked ||
L
Linus Torvalds 已提交
1550
		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
1551
		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
L
Linus Torvalds 已提交
1552 1553 1554 1555 1556 1557
		    /*
		     * 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.
		     */
1558 1559 1560 1561 1562
		    (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
1563
			time_to_ack = true;
L
Linus Torvalds 已提交
1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584
	}

	/* 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
1585
				time_to_ack = true;
L
Linus Torvalds 已提交
1586 1587 1588 1589 1590 1591
		}
	}
	if (time_to_ack)
		tcp_send_ack(sk);
}

1592
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
L
Linus Torvalds 已提交
1593 1594 1595 1596
{
	struct sk_buff *skb;
	u32 offset;

1597
	while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
L
Linus Torvalds 已提交
1598
		offset = seq - TCP_SKB_CB(skb)->seq;
1599 1600
		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
1601
			offset--;
1602
		}
1603
		if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
L
Linus Torvalds 已提交
1604 1605 1606
			*off = offset;
			return skb;
		}
1607 1608 1609 1610
		/* 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
1611
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639
	}
	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) {
1640 1641
			int used;
			size_t len;
L
Linus Torvalds 已提交
1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652

			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);
1653
			if (used <= 0) {
1654 1655 1656 1657
				if (!copied)
					copied = used;
				break;
			} else if (used <= len) {
L
Linus Torvalds 已提交
1658 1659 1660 1661
				seq += used;
				copied += used;
				offset += used;
			}
1662
			/* If recv_actor drops the lock (e.g. TCP splice
1663 1664 1665 1666
			 * receive) the skb pointer might be invalid when
			 * getting here: tcp_collapse might have deleted it
			 * while aggregating skbs from the socket queue.
			 */
1667 1668
			skb = tcp_recv_skb(sk, seq - 1, &offset);
			if (!skb)
L
Linus Torvalds 已提交
1669
				break;
1670 1671 1672 1673 1674
			/* 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
1675
		}
1676
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
D
Dan Williams 已提交
1677
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1678 1679 1680
			++seq;
			break;
		}
D
Dan Williams 已提交
1681
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1682 1683
		if (!desc->count)
			break;
1684
		tp->copied_seq = seq;
L
Linus Torvalds 已提交
1685 1686 1687 1688 1689 1690
	}
	tp->copied_seq = seq;

	tcp_rcv_space_adjust(sk);

	/* Clean up data we have read: This will do ACK frames. */
1691 1692
	if (copied > 0) {
		tcp_recv_skb(sk, seq, &offset);
1693
		tcp_cleanup_rbuf(sk, copied);
1694
	}
L
Linus Torvalds 已提交
1695 1696
	return copied;
}
E
Eric Dumazet 已提交
1697
EXPORT_SYMBOL(tcp_read_sock);
L
Linus Torvalds 已提交
1698

1699 1700 1701 1702 1703 1704
int tcp_peek_len(struct socket *sock)
{
	return tcp_inq(sock->sk);
}
EXPORT_SYMBOL(tcp_peek_len);

1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719
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 */
1720 1721
static void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
			       struct scm_timestamping *tss)
1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759
{
	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
1760 1761 1762 1763 1764 1765 1766 1767
/*
 *	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.
 */

1768 1769
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
1770 1771 1772 1773 1774 1775 1776 1777 1778
{
	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;
1779
	struct sk_buff *skb, *last;
I
Ilpo Järvinen 已提交
1780
	u32 urg_hole = 0;
1781 1782
	struct scm_timestamping tss;
	bool has_tss = false;
L
Linus Torvalds 已提交
1783

1784
	if (unlikely(flags & MSG_ERRQUEUE))
1785
		return inet_recv_error(sk, msg, len, addr_len);
1786

1787 1788 1789
	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
	    (sk->sk_state == TCP_ESTABLISHED))
		sk_busy_loop(sk, nonblock);
1790

L
Linus Torvalds 已提交
1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802
	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
1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817
	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
1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840
	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. */

1841
		last = skb_peek_tail(&sk->sk_receive_queue);
1842
		skb_queue_walk(&sk->sk_receive_queue, skb) {
1843
			last = skb;
L
Linus Torvalds 已提交
1844 1845 1846
			/* Now that we have two receive queues this
			 * shouldn't happen.
			 */
1847
			if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
J
Joe Perches 已提交
1848 1849 1850
				 "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
1851
				break;
1852

L
Linus Torvalds 已提交
1853
			offset = *seq - TCP_SKB_CB(skb)->seq;
1854 1855
			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
1856
				offset--;
1857
			}
L
Linus Torvalds 已提交
1858 1859
			if (offset < skb->len)
				goto found_ok_skb;
1860
			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1861
				goto found_fin_ok;
J
Joe Perches 已提交
1862 1863 1864
			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);
1865
		}
L
Linus Torvalds 已提交
1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876

		/* 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 ||
1877
			    signal_pending(current))
L
Linus Torvalds 已提交
1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912
				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;
			}
		}

1913
		tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1914 1915 1916 1917 1918

		if (copied >= target) {
			/* Do not sleep, just process backlog. */
			release_sock(sk);
			lock_sock(sk);
1919 1920 1921
		} else {
			sk_wait_data(sk, &timeo, last);
		}
L
Linus Torvalds 已提交
1922

I
Ilpo Järvinen 已提交
1923 1924
		if ((flags & MSG_PEEK) &&
		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
1925 1926 1927
			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
1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944
			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
1945
						urg_hole++;
L
Linus Torvalds 已提交
1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956
						offset++;
						used--;
						if (!used)
							goto skip_copy;
					}
				} else
					used = urg_offset;
			}
		}

		if (!(flags & MSG_TRUNC)) {
1957
			err = skb_copy_datagram_msg(skb, offset, msg, used);
D
Dan Williams 已提交
1958 1959 1960 1961 1962
			if (err) {
				/* Exception. Bailout! */
				if (!copied)
					copied = -EFAULT;
				break;
L
Linus Torvalds 已提交
1963 1964 1965 1966 1967 1968 1969 1970 1971 1972
			}
		}

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

		tcp_rcv_space_adjust(sk);

skip_copy:
1973
		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
L
Linus Torvalds 已提交
1974
			tp->urg_data = 0;
1975 1976
			tcp_fast_path_check(sk);
		}
L
Linus Torvalds 已提交
1977 1978 1979
		if (used + offset < skb->len)
			continue;

1980 1981 1982 1983
		if (TCP_SKB_CB(skb)->has_rxtstamp) {
			tcp_update_recv_tstamps(skb, &tss);
			has_tss = true;
		}
1984
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1985
			goto found_fin_ok;
D
Dan Williams 已提交
1986 1987
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1988 1989 1990 1991 1992
		continue;

	found_fin_ok:
		/* Process the FIN. */
		++*seq;
D
Dan Williams 已提交
1993 1994
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1995 1996 1997 1998 1999 2000 2001
		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
	 */

2002 2003 2004
	if (has_tss)
		tcp_recv_timestamp(msg, sk, &tss);

L
Linus Torvalds 已提交
2005
	/* Clean up data we have read: This will do ACK frames. */
2006
	tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
2007 2008 2009 2010 2011 2012 2013 2014 2015

	release_sock(sk);
	return copied;

out:
	release_sock(sk);
	return err;

recv_urg:
2016
	err = tcp_recv_urg(sk, msg, len, flags);
L
Linus Torvalds 已提交
2017
	goto out;
P
Pavel Emelyanov 已提交
2018 2019 2020 2021

recv_sndq:
	err = tcp_peek_sndq(sk, msg, len);
	goto out;
L
Linus Torvalds 已提交
2022
}
E
Eric Dumazet 已提交
2023
EXPORT_SYMBOL(tcp_recvmsg);
L
Linus Torvalds 已提交
2024

I
Ilpo Järvinen 已提交
2025 2026 2027 2028
void tcp_set_state(struct sock *sk, int state)
{
	int oldstate = sk->sk_state;

L
Lawrence Brakmo 已提交
2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051
	/* 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);
2052

I
Ilpo Järvinen 已提交
2053 2054 2055
	switch (state) {
	case TCP_ESTABLISHED:
		if (oldstate != TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2056
			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2057 2058 2059 2060
		break;

	case TCP_CLOSE:
		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2061
			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
I
Ilpo Järvinen 已提交
2062 2063 2064 2065

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2066
			inet_put_port(sk);
I
Ilpo Järvinen 已提交
2067 2068
		/* fall through */
	default:
2069
		if (oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2070
			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2071 2072 2073 2074 2075
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
2076
	inet_sk_state_store(sk, state);
I
Ilpo Järvinen 已提交
2077 2078

#ifdef STATE_TRACE
2079
	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
I
Ilpo Järvinen 已提交
2080 2081 2082 2083
#endif
}
EXPORT_SYMBOL_GPL(tcp_set_state);

L
Linus Torvalds 已提交
2084 2085 2086 2087 2088 2089 2090
/*
 *	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.
 */

2091
static const unsigned char new_state[16] = {
L
Linus Torvalds 已提交
2092
  /* current state:        new state:      action:	*/
2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105
  [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
2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119
};

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
2120
 *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
L
Linus Torvalds 已提交
2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140
 */

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
2141
EXPORT_SYMBOL(tcp_shutdown);
L
Linus Torvalds 已提交
2142

A
Arun Sharma 已提交
2143 2144 2145 2146 2147 2148 2149
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);

2150 2151 2152 2153
	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
2154 2155 2156
	return too_many_orphans || out_of_socket_memory;
}

L
Linus Torvalds 已提交
2157 2158 2159 2160
void tcp_close(struct sock *sk, long timeout)
{
	struct sk_buff *skb;
	int data_was_unread = 0;
H
Herbert Xu 已提交
2161
	int state;
L
Linus Torvalds 已提交
2162 2163 2164 2165 2166 2167 2168 2169

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

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

		/* Special case. */
2170
		inet_csk_listen_stop(sk);
L
Linus Torvalds 已提交
2171 2172 2173 2174 2175 2176 2177 2178 2179

		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) {
2180 2181 2182 2183
		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
2184 2185 2186 2187
		data_was_unread += len;
		__kfree_skb(skb);
	}

2188
	sk_mem_reclaim(sk);
L
Linus Torvalds 已提交
2189

2190 2191 2192 2193
	/* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
	if (sk->sk_state == TCP_CLOSE)
		goto adjudge_to_death;

2194 2195 2196 2197 2198 2199
	/* 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
2200
	 */
P
Pavel Emelyanov 已提交
2201 2202 2203
	if (unlikely(tcp_sk(sk)->repair)) {
		sk->sk_prot->disconnect(sk, 0);
	} else if (data_was_unread) {
L
Linus Torvalds 已提交
2204
		/* Unread data was tossed, zap the connection. */
2205
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
L
Linus Torvalds 已提交
2206
		tcp_set_state(sk, TCP_CLOSE);
2207
		tcp_send_active_reset(sk, sk->sk_allocation);
L
Linus Torvalds 已提交
2208 2209 2210
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
2211
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
L
Linus Torvalds 已提交
2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236
	} 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
2237 2238 2239 2240
		 * 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
2241 2242 2243 2244 2245 2246 2247
		 */
		tcp_send_fin(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
H
Herbert Xu 已提交
2248 2249 2250 2251
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

L
Linus Torvalds 已提交
2252 2253 2254 2255 2256
	/* 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
2257
	 *  to finish close. No need to check for user refs.
L
Linus Torvalds 已提交
2258 2259 2260
	 */
	local_bh_disable();
	bh_lock_sock(sk);
2261
	WARN_ON(sock_owned_by_user(sk));
L
Linus Torvalds 已提交
2262

H
Herbert Xu 已提交
2263 2264
	percpu_counter_inc(sk->sk_prot->orphan_count);

H
Herbert Xu 已提交
2265 2266 2267
	/* 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
2268 2269 2270 2271

	/*	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.
2272
	 *	We use a 1 minute timeout (about the same as BSD) then kill
L
Linus Torvalds 已提交
2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287
	 *	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);
2288
			__NET_INC_STATS(sock_net(sk),
2289
					LINUX_MIB_TCPABORTONLINGER);
L
Linus Torvalds 已提交
2290
		} else {
2291
			const int tmo = tcp_fin_time(sk);
L
Linus Torvalds 已提交
2292 2293

			if (tmo > TCP_TIMEWAIT_LEN) {
2294 2295
				inet_csk_reset_keepalive_timer(sk,
						tmo - TCP_TIMEWAIT_LEN);
L
Linus Torvalds 已提交
2296 2297 2298 2299 2300 2301 2302
			} else {
				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
				goto out;
			}
		}
	}
	if (sk->sk_state != TCP_CLOSE) {
2303
		sk_mem_reclaim(sk);
A
Arun Sharma 已提交
2304
		if (tcp_check_oom(sk, 0)) {
L
Linus Torvalds 已提交
2305 2306
			tcp_set_state(sk, TCP_CLOSE);
			tcp_send_active_reset(sk, GFP_ATOMIC);
2307
			__NET_INC_STATS(sock_net(sk),
2308
					LINUX_MIB_TCPABORTONMEMORY);
2309 2310 2311
		} 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
2312 2313 2314
		}
	}

2315 2316 2317 2318 2319 2320
	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.
		 */
2321
		if (req)
2322
			reqsk_fastopen_remove(sk, req, false);
2323
		inet_csk_destroy_sock(sk);
2324
	}
L
Linus Torvalds 已提交
2325 2326 2327 2328 2329 2330 2331
	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}
E
Eric Dumazet 已提交
2332
EXPORT_SYMBOL(tcp_close);
L
Linus Torvalds 已提交
2333 2334 2335

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

E
Eric Dumazet 已提交
2336
static inline bool tcp_need_reset(int state)
L
Linus Torvalds 已提交
2337 2338 2339 2340 2341 2342
{
	return (1 << state) &
	       (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
		TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
}

2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358
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);
	}
}

2359 2360 2361 2362 2363 2364 2365 2366 2367
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);
	}
2368
	tcp_rtx_queue_purge(sk);
2369 2370 2371
	INIT_LIST_HEAD(&tcp_sk(sk)->tsorted_sent_queue);
	sk_mem_reclaim(sk);
	tcp_clear_all_retrans_hints(tcp_sk(sk));
2372
	tcp_sk(sk)->packets_out = 0;
2373 2374
}

L
Linus Torvalds 已提交
2375 2376 2377
int tcp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
2378
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2379 2380 2381 2382 2383 2384 2385 2386 2387
	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) {
2388
		inet_csk_listen_stop(sk);
P
Pavel Emelyanov 已提交
2389 2390
	} else if (unlikely(tp->repair)) {
		sk->sk_err = ECONNABORTED;
L
Linus Torvalds 已提交
2391 2392 2393
	} 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
2394
		/* The last check adjusts for discrepancy of Linux wrt. RFC
L
Linus Torvalds 已提交
2395 2396 2397 2398 2399 2400 2401 2402 2403
		 * 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);
2404
	tcp_write_queue_purge(sk);
2405
	tcp_fastopen_active_disable_ofo_check(sk);
2406
	skb_rbtree_purge(&tp->out_of_order_queue);
L
Linus Torvalds 已提交
2407

E
Eric Dumazet 已提交
2408
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
2409 2410 2411 2412 2413 2414

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

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);
2415
	tp->srtt_us = 0;
2416 2417
	tp->write_seq += tp->max_window + 2;
	if (tp->write_seq == 0)
L
Linus Torvalds 已提交
2418
		tp->write_seq = 1;
2419
	icsk->icsk_backoff = 0;
L
Linus Torvalds 已提交
2420
	tp->snd_cwnd = 2;
2421
	icsk->icsk_probes_out = 0;
I
Ilpo Järvinen 已提交
2422
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
L
Linus Torvalds 已提交
2423
	tp->snd_cwnd_cnt = 0;
2424
	tp->window_clamp = 0;
2425
	tcp_set_ca_state(sk, TCP_CA_Open);
2426
	tp->is_sack_reneg = 0;
L
Linus Torvalds 已提交
2427
	tcp_clear_retrans(tp);
2428
	inet_csk_delack_init(sk);
2429 2430 2431 2432
	/* 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;
2433
	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
L
Linus Torvalds 已提交
2434
	__sk_dst_reset(sk);
2435 2436
	dst_release(sk->sk_rx_dst);
	sk->sk_rx_dst = NULL;
2437
	tcp_saved_syn_free(tp);
L
Linus Torvalds 已提交
2438

2439 2440 2441 2442
	/* Clean up fastopen related fields */
	tcp_free_fastopen_req(tp);
	inet->defer_connect = 0;

E
Eric Dumazet 已提交
2443
	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
L
Linus Torvalds 已提交
2444

2445 2446 2447 2448 2449 2450
	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
2451 2452 2453
	sk->sk_error_report(sk);
	return err;
}
E
Eric Dumazet 已提交
2454
EXPORT_SYMBOL(tcp_disconnect);
L
Linus Torvalds 已提交
2455

E
Eric Dumazet 已提交
2456
static inline bool tcp_can_repair_sock(const struct sock *sk)
P
Pavel Emelyanov 已提交
2457
{
2458
	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2459
		(sk->sk_state != TCP_LISTEN);
P
Pavel Emelyanov 已提交
2460 2461
}

2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493
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;
}

2494
static int tcp_repair_options_est(struct sock *sk,
2495
		struct tcp_repair_opt __user *optbuf, unsigned int len)
2496
{
2497
	struct tcp_sock *tp = tcp_sk(sk);
2498
	struct tcp_repair_opt opt;
2499

2500 2501
	while (len >= sizeof(opt)) {
		if (copy_from_user(&opt, optbuf, sizeof(opt)))
2502 2503 2504
			return -EFAULT;

		optbuf++;
2505
		len -= sizeof(opt);
2506

2507 2508 2509
		switch (opt.opt_code) {
		case TCPOPT_MSS:
			tp->rx_opt.mss_clamp = opt.opt_val;
2510
			tcp_mtup_init(sk);
2511
			break;
2512
		case TCPOPT_WINDOW:
2513 2514 2515 2516
			{
				u16 snd_wscale = opt.opt_val & 0xFFFF;
				u16 rcv_wscale = opt.opt_val >> 16;

2517
				if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2518
					return -EFBIG;
2519

2520 2521 2522 2523
				tp->rx_opt.snd_wscale = snd_wscale;
				tp->rx_opt.rcv_wscale = rcv_wscale;
				tp->rx_opt.wscale_ok = 1;
			}
2524 2525
			break;
		case TCPOPT_SACK_PERM:
2526 2527 2528
			if (opt.opt_val != 0)
				return -EINVAL;

2529 2530 2531
			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
			break;
		case TCPOPT_TIMESTAMP:
2532 2533 2534
			if (opt.opt_val != 0)
				return -EINVAL;

2535 2536 2537 2538 2539 2540 2541 2542
			tp->rx_opt.tstamp_ok = 1;
			break;
		}
	}

	return 0;
}

L
Linus Torvalds 已提交
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/*
 *	Socket option code for TCP.
 */
2546
static int do_tcp_setsockopt(struct sock *sk, int level,
2547
		int optname, char __user *optval, unsigned int optlen)
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{
	struct tcp_sock *tp = tcp_sk(sk);
2550
	struct inet_connection_sock *icsk = inet_csk(sk);
2551
	struct net *net = sock_net(sk);
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	int val;
	int err = 0;

2555 2556 2557
	/* These are data/string values, all the others are ints */
	switch (optname) {
	case TCP_CONGESTION: {
2558 2559 2560 2561 2562 2563
		char name[TCP_CA_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
2564
					min_t(long, TCP_CA_NAME_MAX-1, optlen));
2565 2566 2567 2568 2569
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
2570
		err = tcp_set_congestion_control(sk, name, true, true);
2571 2572 2573
		release_sock(sk);
		return err;
	}
D
Dave Watson 已提交
2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591
	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;
	}
2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602
	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));
	}
2603 2604 2605
	default:
		/* fallthru */
		break;
2606
	}
2607

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2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619
	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
2620 2621
		 * know which interface is going to be used
		 */
2622
		if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
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2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639
			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;
2640
			tcp_push_pending_frames(sk);
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2641 2642 2643 2644 2645
		} else {
			tp->nonagle &= ~TCP_NAGLE_OFF;
		}
		break;

A
Andreas Petlund 已提交
2646 2647 2648 2649 2650 2651 2652
	case TCP_THIN_LINEAR_TIMEOUTS:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->thin_lto = val;
		break;

A
Andreas Petlund 已提交
2653 2654 2655 2656 2657
	case TCP_THIN_DUPACK:
		if (val < 0 || val > 1)
			err = -EINVAL;
		break;

P
Pavel Emelyanov 已提交
2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693
	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;

2694 2695 2696 2697
	case TCP_REPAIR_OPTIONS:
		if (!tp->repair)
			err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
2698
			err = tcp_repair_options_est(sk,
2699 2700
					(struct tcp_repair_opt __user *)optval,
					optlen);
2701 2702 2703 2704
		else
			err = -EPERM;
		break;

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Linus Torvalds 已提交
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	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;
2723
			tcp_push_pending_frames(sk);
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Linus Torvalds 已提交
2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734
		}
		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))) {
2735
				u32 elapsed = keepalive_time_elapsed(tp);
L
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2736 2737 2738 2739
				if (tp->keepalive_time > elapsed)
					elapsed = tp->keepalive_time - elapsed;
				else
					elapsed = 0;
2740
				inet_csk_reset_keepalive_timer(sk, elapsed);
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Linus Torvalds 已提交
2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759
			}
		}
		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
2760
			icsk->icsk_syn_retries = val;
L
Linus Torvalds 已提交
2761 2762
		break;

2763 2764 2765 2766 2767 2768 2769
	case TCP_SAVE_SYN:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->save_syn = val;
		break;

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	case TCP_LINGER2:
		if (val < 0)
			tp->linger2 = -1;
2773
		else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
L
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2774 2775 2776 2777 2778 2779
			tp->linger2 = 0;
		else
			tp->linger2 = val * HZ;
		break;

	case TCP_DEFER_ACCEPT:
2780 2781 2782 2783
		/* 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);
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Linus Torvalds 已提交
2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799
		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) {
2800
			icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2801
		} else {
2802
			icsk->icsk_ack.pingpong = 0;
L
Linus Torvalds 已提交
2803 2804
			if ((1 << sk->sk_state) &
			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2805 2806
			    inet_csk_ack_scheduled(sk)) {
				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2807
				tcp_cleanup_rbuf(sk, 1);
L
Linus Torvalds 已提交
2808
				if (!(val & 1))
2809
					icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2810 2811 2812 2813
			}
		}
		break;

2814 2815
#ifdef CONFIG_TCP_MD5SIG
	case TCP_MD5SIG:
2816
	case TCP_MD5SIG_EXT:
2817 2818 2819 2820
		if ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN))
			err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
		else
			err = -EINVAL;
2821 2822
		break;
#endif
2823
	case TCP_USER_TIMEOUT:
2824
		/* Cap the max time in ms TCP will retry or probe the window
2825 2826
		 * before giving up and aborting (ETIMEDOUT) a connection.
		 */
2827 2828 2829 2830
		if (val < 0)
			err = -EINVAL;
		else
			icsk->icsk_user_timeout = msecs_to_jiffies(val);
2831
		break;
2832 2833 2834

	case TCP_FASTOPEN:
		if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2835
		    TCPF_LISTEN))) {
2836
			tcp_fastopen_init_key_once(net);
2837

2838
			fastopen_queue_tune(sk, val);
2839
		} else {
2840
			err = -EINVAL;
2841
		}
2842
		break;
W
Wei Wang 已提交
2843 2844 2845
	case TCP_FASTOPEN_CONNECT:
		if (val > 1 || val < 0) {
			err = -EINVAL;
2846
		} else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
W
Wei Wang 已提交
2847 2848 2849 2850 2851 2852 2853 2854
			if (sk->sk_state == TCP_CLOSE)
				tp->fastopen_connect = val;
			else
				err = -EINVAL;
		} else {
			err = -EOPNOTSUPP;
		}
		break;
2855 2856 2857 2858 2859 2860 2861 2862
	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;
2863 2864 2865 2866
	case TCP_TIMESTAMP:
		if (!tp->repair)
			err = -EPERM;
		else
2867
			tp->tsoffset = val - tcp_time_stamp_raw();
2868
		break;
2869 2870 2871
	case TCP_REPAIR_WINDOW:
		err = tcp_repair_set_window(tp, optval, optlen);
		break;
2872 2873 2874 2875
	case TCP_NOTSENT_LOWAT:
		tp->notsent_lowat = val;
		sk->sk_write_space(sk);
		break;
L
Linus Torvalds 已提交
2876 2877 2878
	default:
		err = -ENOPROTOOPT;
		break;
2879 2880
	}

L
Linus Torvalds 已提交
2881 2882 2883 2884
	release_sock(sk);
	return err;
}

2885
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2886
		   unsigned int optlen)
2887
{
2888
	const struct inet_connection_sock *icsk = inet_csk(sk);
2889 2890 2891 2892 2893 2894

	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
2895
EXPORT_SYMBOL(tcp_setsockopt);
2896 2897

#ifdef CONFIG_COMPAT
2898
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2899
			  char __user *optval, unsigned int optlen)
2900
{
2901 2902 2903
	if (level != SOL_TCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
2904 2905
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
2906
EXPORT_SYMBOL(compat_tcp_setsockopt);
2907 2908
#endif

2909 2910 2911 2912 2913 2914 2915 2916 2917
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)
2918
			stats[i] += tcp_jiffies32 - tp->chrono_start;
2919 2920 2921 2922 2923 2924 2925 2926 2927
		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
2928
/* Return information about state of tcp endpoint in API format. */
2929
void tcp_get_info(struct sock *sk, struct tcp_info *info)
L
Linus Torvalds 已提交
2930
{
2931
	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
2932
	const struct inet_connection_sock *icsk = inet_csk(sk);
2933
	u32 now;
2934
	u64 rate64;
2935
	bool slow;
2936
	u32 rate;
L
Linus Torvalds 已提交
2937 2938

	memset(info, 0, sizeof(*info));
2939 2940
	if (sk->sk_type != SOCK_STREAM)
		return;
L
Linus Torvalds 已提交
2941

2942
	info->tcpi_state = inet_sk_state_load(sk);
2943

2944 2945 2946
	/* Report meaningful fields for all TCP states, including listeners */
	rate = READ_ONCE(sk->sk_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2947
	info->tcpi_pacing_rate = rate64;
2948 2949 2950

	rate = READ_ONCE(sk->sk_max_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2951
	info->tcpi_max_pacing_rate = rate64;
2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964

	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;
	}
2965 2966 2967

	slow = lock_sock_fast(sk);

2968
	info->tcpi_ca_state = icsk->icsk_ca_state;
2969
	info->tcpi_retransmits = icsk->icsk_retransmits;
2970
	info->tcpi_probes = icsk->icsk_probes_out;
2971
	info->tcpi_backoff = icsk->icsk_backoff;
L
Linus Torvalds 已提交
2972 2973 2974

	if (tp->rx_opt.tstamp_ok)
		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2975
	if (tcp_is_sack(tp))
L
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2976 2977 2978 2979 2980
		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;
2981
	}
L
Linus Torvalds 已提交
2982

E
Eric Dumazet 已提交
2983
	if (tp->ecn_flags & TCP_ECN_OK)
L
Linus Torvalds 已提交
2984
		info->tcpi_options |= TCPI_OPT_ECN;
E
Eric Dumazet 已提交
2985 2986
	if (tp->ecn_flags & TCP_ECN_SEEN)
		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Y
Yuchung Cheng 已提交
2987 2988
	if (tp->syn_data_acked)
		info->tcpi_options |= TCPI_OPT_SYN_DATA;
L
Linus Torvalds 已提交
2989

2990 2991
	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2992
	info->tcpi_snd_mss = tp->mss_cache;
2993
	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
L
Linus Torvalds 已提交
2994

2995 2996 2997
	info->tcpi_unacked = tp->packets_out;
	info->tcpi_sacked = tp->sacked_out;

L
Linus Torvalds 已提交
2998 2999 3000
	info->tcpi_lost = tp->lost_out;
	info->tcpi_retrans = tp->retrans_out;

3001
	now = tcp_jiffies32;
L
Linus Torvalds 已提交
3002
	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
3003
	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
L
Linus Torvalds 已提交
3004 3005
	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);

3006
	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
L
Linus Torvalds 已提交
3007
	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
3008 3009
	info->tcpi_rtt = tp->srtt_us >> 3;
	info->tcpi_rttvar = tp->mdev_us >> 2;
L
Linus Torvalds 已提交
3010 3011 3012
	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
	info->tcpi_advmss = tp->advmss;

3013
	info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
L
Linus Torvalds 已提交
3014 3015 3016
	info->tcpi_rcv_space = tp->rcvq_space.space;

	info->tcpi_total_retrans = tp->total_retrans;
3017

3018 3019
	info->tcpi_bytes_acked = tp->bytes_acked;
	info->tcpi_bytes_received = tp->bytes_received;
3020
	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
3021
	tcp_get_info_chrono_stats(tp, info);
3022

3023 3024
	info->tcpi_segs_out = tp->segs_out;
	info->tcpi_segs_in = tp->segs_in;
3025 3026

	info->tcpi_min_rtt = tcp_min_rtt(tp);
3027 3028
	info->tcpi_data_segs_in = tp->data_segs_in;
	info->tcpi_data_segs_out = tp->data_segs_out;
Y
Yuchung Cheng 已提交
3029 3030

	info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
3031 3032
	rate64 = tcp_compute_delivery_rate(tp);
	if (rate64)
3033
		info->tcpi_delivery_rate = rate64;
3034
	unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
3035 3036 3037
}
EXPORT_SYMBOL_GPL(tcp_get_info);

3038 3039 3040 3041 3042
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;
3043 3044
	u64 rate64;
	u32 rate;
3045

3046
	stats = alloc_skb(7 * nla_total_size_64bit(sizeof(u64)) +
3047
			  5 * nla_total_size(sizeof(u32)) +
3048
			  3 * nla_total_size(sizeof(u8)), GFP_ATOMIC);
3049 3050 3051 3052 3053 3054 3055 3056 3057 3058
	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);
3059 3060 3061 3062
	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);
3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076

	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);
3077
	nla_put_u32(stats, TCP_NLA_SND_SSTHRESH, tp->snd_ssthresh);
3078 3079

	nla_put_u32(stats, TCP_NLA_SNDQ_SIZE, tp->write_seq - tp->snd_una);
3080
	nla_put_u8(stats, TCP_NLA_CA_STATE, inet_csk(sk)->icsk_ca_state);
3081 3082 3083
	return stats;
}

3084 3085
static int do_tcp_getsockopt(struct sock *sk, int level,
		int optname, char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
3086
{
3087
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
3088
	struct tcp_sock *tp = tcp_sk(sk);
3089
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101
	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:
3102
		val = tp->mss_cache;
L
Linus Torvalds 已提交
3103 3104
		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			val = tp->rx_opt.user_mss;
3105 3106
		if (tp->repair)
			val = tp->rx_opt.mss_clamp;
L
Linus Torvalds 已提交
3107 3108 3109 3110 3111 3112 3113 3114
		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
3115
		val = keepalive_time_when(tp) / HZ;
L
Linus Torvalds 已提交
3116 3117
		break;
	case TCP_KEEPINTVL:
E
Eric Dumazet 已提交
3118
		val = keepalive_intvl_when(tp) / HZ;
L
Linus Torvalds 已提交
3119 3120
		break;
	case TCP_KEEPCNT:
E
Eric Dumazet 已提交
3121
		val = keepalive_probes(tp);
L
Linus Torvalds 已提交
3122 3123
		break;
	case TCP_SYNCNT:
3124
		val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
L
Linus Torvalds 已提交
3125 3126 3127 3128
		break;
	case TCP_LINGER2:
		val = tp->linger2;
		if (val >= 0)
3129
			val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
L
Linus Torvalds 已提交
3130 3131
		break;
	case TCP_DEFER_ACCEPT:
3132 3133
		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
3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152
		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;
	}
3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172
	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
3173
	case TCP_QUICKACK:
3174
		val = !icsk->icsk_ack.pingpong;
L
Linus Torvalds 已提交
3175
		break;
3176 3177 3178 3179 3180 3181 3182

	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;
3183
		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
3184 3185
			return -EFAULT;
		return 0;
3186

D
Dave Watson 已提交
3187 3188 3189 3190
	case TCP_ULP:
		if (get_user(len, optlen))
			return -EFAULT;
		len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
3191 3192 3193 3194 3195
		if (!icsk->icsk_ulp_ops) {
			if (put_user(0, optlen))
				return -EFAULT;
			return 0;
		}
D
Dave Watson 已提交
3196 3197 3198 3199 3200 3201
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len))
			return -EFAULT;
		return 0;

3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223
	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;
	}
3224 3225 3226
	case TCP_THIN_LINEAR_TIMEOUTS:
		val = tp->thin_lto;
		break;
Y
Yuchung Cheng 已提交
3227

3228
	case TCP_THIN_DUPACK:
Y
Yuchung Cheng 已提交
3229
		val = 0;
3230
		break;
3231

P
Pavel Emelyanov 已提交
3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242
	case TCP_REPAIR:
		val = tp->repair;
		break;

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

3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264
	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
3265 3266 3267 3268 3269 3270 3271 3272 3273
	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;

3274 3275 3276
	case TCP_USER_TIMEOUT:
		val = jiffies_to_msecs(icsk->icsk_user_timeout);
		break;
3277 3278

	case TCP_FASTOPEN:
3279
		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3280 3281
		break;

W
Wei Wang 已提交
3282 3283 3284 3285
	case TCP_FASTOPEN_CONNECT:
		val = tp->fastopen_connect;
		break;

3286 3287 3288 3289
	case TCP_FASTOPEN_NO_COOKIE:
		val = tp->fastopen_no_cookie;
		break;

3290
	case TCP_TIMESTAMP:
3291
		val = tcp_time_stamp_raw() + tp->tsoffset;
3292
		break;
3293 3294 3295
	case TCP_NOTSENT_LOWAT:
		val = tp->notsent_lowat;
		break;
3296 3297 3298 3299 3300 3301 3302 3303 3304
	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) {
3305 3306 3307 3308 3309 3310 3311 3312 3313
			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];
3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331
			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
3332 3333
	default:
		return -ENOPROTOOPT;
3334
	}
L
Linus Torvalds 已提交
3335 3336 3337 3338 3339 3340 3341 3342

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

3343 3344 3345 3346 3347 3348 3349 3350 3351 3352
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
3353
EXPORT_SYMBOL(tcp_getsockopt);
3354 3355

#ifdef CONFIG_COMPAT
3356 3357
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
			  char __user *optval, int __user *optlen)
3358
{
3359 3360 3361
	if (level != SOL_TCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
3362 3363
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
3364
EXPORT_SYMBOL(compat_tcp_getsockopt);
3365
#endif
L
Linus Torvalds 已提交
3366

3367
#ifdef CONFIG_TCP_MD5SIG
E
Eric Dumazet 已提交
3368
static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3369
static DEFINE_MUTEX(tcp_md5sig_mutex);
E
Eric Dumazet 已提交
3370
static bool tcp_md5sig_pool_populated = false;
3371

3372
static void __tcp_alloc_md5sig_pool(void)
3373
{
H
Herbert Xu 已提交
3374
	struct crypto_ahash *hash;
3375 3376
	int cpu;

H
Herbert Xu 已提交
3377
	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3378
	if (IS_ERR(hash))
H
Herbert Xu 已提交
3379 3380
		return;

3381
	for_each_possible_cpu(cpu) {
3382
		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
H
Herbert Xu 已提交
3383
		struct ahash_request *req;
3384

3385 3386 3387 3388 3389 3390 3391 3392 3393
		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
3394 3395 3396 3397 3398 3399 3400 3401 3402 3403
		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;
3404
	}
E
Eric Dumazet 已提交
3405 3406
	/* before setting tcp_md5sig_pool_populated, we must commit all writes
	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3407 3408
	 */
	smp_wmb();
E
Eric Dumazet 已提交
3409
	tcp_md5sig_pool_populated = true;
3410 3411
}

3412
bool tcp_alloc_md5sig_pool(void)
3413
{
E
Eric Dumazet 已提交
3414
	if (unlikely(!tcp_md5sig_pool_populated)) {
3415 3416
		mutex_lock(&tcp_md5sig_mutex);

E
Eric Dumazet 已提交
3417
		if (!tcp_md5sig_pool_populated)
3418 3419 3420
			__tcp_alloc_md5sig_pool();

		mutex_unlock(&tcp_md5sig_mutex);
3421
	}
E
Eric Dumazet 已提交
3422
	return tcp_md5sig_pool_populated;
3423 3424 3425
}
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);

E
Eric Dumazet 已提交
3426 3427 3428 3429 3430 3431 3432 3433 3434

/**
 *	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)
3435
{
E
Eric Dumazet 已提交
3436
	local_bh_disable();
3437

E
Eric Dumazet 已提交
3438 3439 3440 3441 3442
	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
3443 3444 3445 3446
	local_bh_enable();
	return NULL;
}
EXPORT_SYMBOL(tcp_get_md5sig_pool);
3447

3448
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3449
			  const struct sk_buff *skb, unsigned int header_len)
3450 3451 3452
{
	struct scatterlist sg;
	const struct tcphdr *tp = tcp_hdr(skb);
H
Herbert Xu 已提交
3453
	struct ahash_request *req = hp->md5_req;
3454 3455 3456
	unsigned int i;
	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
					   skb_headlen(skb) - header_len : 0;
3457
	const struct skb_shared_info *shi = skb_shinfo(skb);
3458
	struct sk_buff *frag_iter;
3459 3460 3461 3462

	sg_init_table(&sg, 1);

	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
H
Herbert Xu 已提交
3463 3464
	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
	if (crypto_ahash_update(req))
3465 3466 3467 3468
		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
3469 3470 3471 3472 3473
		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
3474 3475
		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
		if (crypto_ahash_update(req))
3476 3477 3478
			return 1;
	}

3479 3480 3481 3482
	skb_walk_frags(skb, frag_iter)
		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
			return 1;

3483 3484 3485 3486
	return 0;
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

3487
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3488 3489 3490 3491
{
	struct scatterlist sg;

	sg_init_one(&sg, key->key, key->keylen);
H
Herbert Xu 已提交
3492 3493
	ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
	return crypto_ahash_update(hp->md5_req);
3494 3495 3496
}
EXPORT_SYMBOL(tcp_md5_hash_key);

3497 3498
#endif

A
Andi Kleen 已提交
3499 3500
void tcp_done(struct sock *sk)
{
3501 3502
	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;

3503
	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3504
		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
A
Andi Kleen 已提交
3505 3506 3507

	tcp_set_state(sk, TCP_CLOSE);
	tcp_clear_xmit_timers(sk);
3508
	if (req)
3509
		reqsk_fastopen_remove(sk, req, false);
A
Andi Kleen 已提交
3510 3511 3512 3513 3514 3515 3516 3517 3518 3519

	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);

3520 3521 3522
int tcp_abort(struct sock *sk, int err)
{
	if (!sk_fullsock(sk)) {
3523 3524 3525 3526 3527 3528 3529 3530 3531
		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;
		}
3532 3533 3534 3535 3536 3537
		return -EOPNOTSUPP;
	}

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

3538 3539 3540 3541 3542
	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);
		inet_csk_listen_stop(sk);
	}

3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558
	/* 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();
3559
	tcp_write_queue_purge(sk);
3560 3561 3562 3563 3564
	release_sock(sk);
	return 0;
}
EXPORT_SYMBOL_GPL(tcp_abort);

3565
extern struct tcp_congestion_ops tcp_reno;
L
Linus Torvalds 已提交
3566 3567 3568 3569

static __initdata unsigned long thash_entries;
static int __init set_thash_entries(char *str)
{
3570 3571
	ssize_t ret;

L
Linus Torvalds 已提交
3572 3573
	if (!str)
		return 0;
3574 3575 3576 3577 3578

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

L
Linus Torvalds 已提交
3579 3580 3581 3582
	return 1;
}
__setup("thash_entries=", set_thash_entries);

F
Fabian Frederick 已提交
3583
static void __init tcp_init_mem(void)
3584
{
E
Eric Dumazet 已提交
3585 3586
	unsigned long limit = nr_free_buffer_pages() / 16;

3587
	limit = max(limit, 128UL);
E
Eric Dumazet 已提交
3588 3589 3590
	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 % */
3591 3592
}

L
Linus Torvalds 已提交
3593 3594
void __init tcp_init(void)
{
3595
	int max_rshare, max_wshare, cnt;
3596
	unsigned long limit;
3597
	unsigned int i;
L
Linus Torvalds 已提交
3598

3599 3600
	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
L
Linus Torvalds 已提交
3601

3602 3603
	percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
	percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3604
	inet_hashinfo_init(&tcp_hashinfo);
3605 3606 3607
	inet_hashinfo2_init(&tcp_hashinfo, "tcp_listen_portaddr_hash",
			    thash_entries, 21,  /* one slot per 2 MB*/
			    0, 64 * 1024);
3608 3609 3610
	tcp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("tcp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
3611
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
3612 3613 3614 3615 3616 3617

	/* Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
3618
	tcp_hashinfo.ehash =
L
Linus Torvalds 已提交
3619
		alloc_large_system_hash("TCP established",
3620
					sizeof(struct inet_ehash_bucket),
L
Linus Torvalds 已提交
3621
					thash_entries,
E
Eric Dumazet 已提交
3622
					17, /* one slot per 128 KB of memory */
3623
					0,
L
Linus Torvalds 已提交
3624
					NULL,
3625
					&tcp_hashinfo.ehash_mask,
3626
					0,
3627
					thash_entries ? 0 : 512 * 1024);
E
Eric Dumazet 已提交
3628
	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3629
		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
E
Eric Dumazet 已提交
3630

3631 3632
	if (inet_ehash_locks_alloc(&tcp_hashinfo))
		panic("TCP: failed to alloc ehash_locks");
3633
	tcp_hashinfo.bhash =
L
Linus Torvalds 已提交
3634
		alloc_large_system_hash("TCP bind",
3635
					sizeof(struct inet_bind_hashbucket),
3636
					tcp_hashinfo.ehash_mask + 1,
E
Eric Dumazet 已提交
3637
					17, /* one slot per 128 KB of memory */
3638
					0,
3639
					&tcp_hashinfo.bhash_size,
L
Linus Torvalds 已提交
3640
					NULL,
3641
					0,
L
Linus Torvalds 已提交
3642
					64 * 1024);
3643
	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3644 3645 3646
	for (i = 0; i < tcp_hashinfo.bhash_size; i++) {
		spin_lock_init(&tcp_hashinfo.bhash[i].lock);
		INIT_HLIST_HEAD(&tcp_hashinfo.bhash[i].chain);
L
Linus Torvalds 已提交
3647 3648
	}

E
Eric Dumazet 已提交
3649 3650 3651

	cnt = tcp_hashinfo.ehash_mask + 1;
	sysctl_tcp_max_orphans = cnt / 2;
L
Linus Torvalds 已提交
3652

3653
	tcp_init_mem();
3654
	/* Set per-socket limits to no more than 1/128 the pressure threshold */
E
Eric Dumazet 已提交
3655
	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3656 3657
	max_wshare = min(4UL*1024*1024, limit);
	max_rshare = min(6UL*1024*1024, limit);
3658

3659 3660 3661
	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);
3662

3663 3664 3665
	init_net.ipv4.sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
	init_net.ipv4.sysctl_tcp_rmem[1] = 87380;
	init_net.ipv4.sysctl_tcp_rmem[2] = max(87380, max_rshare);
L
Linus Torvalds 已提交
3666

3667
	pr_info("Hash tables configured (established %u bind %u)\n",
J
Joe Perches 已提交
3668
		tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3669

3670
	tcp_v4_init();
3671
	tcp_metrics_init();
3672
	BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
E
Eric Dumazet 已提交
3673
	tcp_tasklet_init();
L
Linus Torvalds 已提交
3674
}