tcp.c 88.4 KB
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/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Implementation of the Transmission Control Protocol(TCP).
 *
8
 * Authors:	Ross Biro
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 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Mark Evans, <evansmp@uhura.aston.ac.uk>
 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
 *		Florian La Roche, <flla@stud.uni-sb.de>
 *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
 *		Linus Torvalds, <torvalds@cs.helsinki.fi>
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *		Matthew Dillon, <dillon@apollo.west.oic.com>
 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
 *		Jorge Cwik, <jorge@laser.satlink.net>
 *
 * Fixes:
 *		Alan Cox	:	Numerous verify_area() calls
 *		Alan Cox	:	Set the ACK bit on a reset
 *		Alan Cox	:	Stopped it crashing if it closed while
 *					sk->inuse=1 and was trying to connect
 *					(tcp_err()).
 *		Alan Cox	:	All icmp error handling was broken
 *					pointers passed where wrong and the
 *					socket was looked up backwards. Nobody
 *					tested any icmp error code obviously.
 *		Alan Cox	:	tcp_err() now handled properly. It
 *					wakes people on errors. poll
 *					behaves and the icmp error race
 *					has gone by moving it into sock.c
 *		Alan Cox	:	tcp_send_reset() fixed to work for
 *					everything not just packets for
 *					unknown sockets.
 *		Alan Cox	:	tcp option processing.
 *		Alan Cox	:	Reset tweaked (still not 100%) [Had
 *					syn rule wrong]
 *		Herp Rosmanith  :	More reset fixes
 *		Alan Cox	:	No longer acks invalid rst frames.
 *					Acking any kind of RST is right out.
 *		Alan Cox	:	Sets an ignore me flag on an rst
 *					receive otherwise odd bits of prattle
 *					escape still
 *		Alan Cox	:	Fixed another acking RST frame bug.
 *					Should stop LAN workplace lockups.
 *		Alan Cox	: 	Some tidyups using the new skb list
 *					facilities
 *		Alan Cox	:	sk->keepopen now seems to work
 *		Alan Cox	:	Pulls options out correctly on accepts
 *		Alan Cox	:	Fixed assorted sk->rqueue->next errors
 *		Alan Cox	:	PSH doesn't end a TCP read. Switched a
 *					bit to skb ops.
 *		Alan Cox	:	Tidied tcp_data to avoid a potential
 *					nasty.
 *		Alan Cox	:	Added some better commenting, as the
 *					tcp is hard to follow
 *		Alan Cox	:	Removed incorrect check for 20 * psh
 *	Michael O'Reilly	:	ack < copied bug fix.
 *	Johannes Stille		:	Misc tcp fixes (not all in yet).
 *		Alan Cox	:	FIN with no memory -> CRASH
 *		Alan Cox	:	Added socket option proto entries.
 *					Also added awareness of them to accept.
 *		Alan Cox	:	Added TCP options (SOL_TCP)
 *		Alan Cox	:	Switched wakeup calls to callbacks,
 *					so the kernel can layer network
 *					sockets.
 *		Alan Cox	:	Use ip_tos/ip_ttl settings.
 *		Alan Cox	:	Handle FIN (more) properly (we hope).
 *		Alan Cox	:	RST frames sent on unsynchronised
 *					state ack error.
 *		Alan Cox	:	Put in missing check for SYN bit.
 *		Alan Cox	:	Added tcp_select_window() aka NET2E
 *					window non shrink trick.
 *		Alan Cox	:	Added a couple of small NET2E timer
 *					fixes
 *		Charles Hedrick :	TCP fixes
 *		Toomas Tamm	:	TCP window fixes
 *		Alan Cox	:	Small URG fix to rlogin ^C ack fight
 *		Charles Hedrick	:	Rewrote most of it to actually work
 *		Linus		:	Rewrote tcp_read() and URG handling
 *					completely
 *		Gerhard Koerting:	Fixed some missing timer handling
 *		Matthew Dillon  :	Reworked TCP machine states as per RFC
 *		Gerhard Koerting:	PC/TCP workarounds
 *		Adam Caldwell	:	Assorted timer/timing errors
 *		Matthew Dillon	:	Fixed another RST bug
 *		Alan Cox	:	Move to kernel side addressing changes.
 *		Alan Cox	:	Beginning work on TCP fastpathing
 *					(not yet usable)
 *		Arnt Gulbrandsen:	Turbocharged tcp_check() routine.
 *		Alan Cox	:	TCP fast path debugging
 *		Alan Cox	:	Window clamping
 *		Michael Riepe	:	Bug in tcp_check()
 *		Matt Dillon	:	More TCP improvements and RST bug fixes
 *		Matt Dillon	:	Yet more small nasties remove from the
 *					TCP code (Be very nice to this man if
 *					tcp finally works 100%) 8)
 *		Alan Cox	:	BSD accept semantics.
 *		Alan Cox	:	Reset on closedown bug.
 *	Peter De Schrijver	:	ENOTCONN check missing in tcp_sendto().
 *		Michael Pall	:	Handle poll() after URG properly in
 *					all cases.
 *		Michael Pall	:	Undo the last fix in tcp_read_urg()
 *					(multi URG PUSH broke rlogin).
 *		Michael Pall	:	Fix the multi URG PUSH problem in
 *					tcp_readable(), poll() after URG
 *					works now.
 *		Michael Pall	:	recv(...,MSG_OOB) never blocks in the
 *					BSD api.
 *		Alan Cox	:	Changed the semantics of sk->socket to
 *					fix a race and a signal problem with
 *					accept() and async I/O.
 *		Alan Cox	:	Relaxed the rules on tcp_sendto().
 *		Yury Shevchuk	:	Really fixed accept() blocking problem.
 *		Craig I. Hagan  :	Allow for BSD compatible TIME_WAIT for
 *					clients/servers which listen in on
 *					fixed ports.
 *		Alan Cox	:	Cleaned the above up and shrank it to
 *					a sensible code size.
 *		Alan Cox	:	Self connect lockup fix.
 *		Alan Cox	:	No connect to multicast.
 *		Ross Biro	:	Close unaccepted children on master
 *					socket close.
 *		Alan Cox	:	Reset tracing code.
 *		Alan Cox	:	Spurious resets on shutdown.
 *		Alan Cox	:	Giant 15 minute/60 second timer error
 *		Alan Cox	:	Small whoops in polling before an
 *					accept.
 *		Alan Cox	:	Kept the state trace facility since
 *					it's handy for debugging.
 *		Alan Cox	:	More reset handler fixes.
 *		Alan Cox	:	Started rewriting the code based on
 *					the RFC's for other useful protocol
 *					references see: Comer, KA9Q NOS, and
 *					for a reference on the difference
 *					between specifications and how BSD
 *					works see the 4.4lite source.
 *		A.N.Kuznetsov	:	Don't time wait on completion of tidy
 *					close.
 *		Linus Torvalds	:	Fin/Shutdown & copied_seq changes.
 *		Linus Torvalds	:	Fixed BSD port reuse to work first syn
 *		Alan Cox	:	Reimplemented timers as per the RFC
 *					and using multiple timers for sanity.
 *		Alan Cox	:	Small bug fixes, and a lot of new
 *					comments.
 *		Alan Cox	:	Fixed dual reader crash by locking
 *					the buffers (much like datagram.c)
 *		Alan Cox	:	Fixed stuck sockets in probe. A probe
 *					now gets fed up of retrying without
 *					(even a no space) answer.
 *		Alan Cox	:	Extracted closing code better
 *		Alan Cox	:	Fixed the closing state machine to
 *					resemble the RFC.
 *		Alan Cox	:	More 'per spec' fixes.
 *		Jorge Cwik	:	Even faster checksumming.
 *		Alan Cox	:	tcp_data() doesn't ack illegal PSH
 *					only frames. At least one pc tcp stack
 *					generates them.
 *		Alan Cox	:	Cache last socket.
 *		Alan Cox	:	Per route irtt.
 *		Matt Day	:	poll()->select() match BSD precisely on error
 *		Alan Cox	:	New buffers
 *		Marc Tamsky	:	Various sk->prot->retransmits and
 *					sk->retransmits misupdating fixed.
 *					Fixed tcp_write_timeout: stuck close,
 *					and TCP syn retries gets used now.
 *		Mark Yarvis	:	In tcp_read_wakeup(), don't send an
 *					ack if state is TCP_CLOSED.
 *		Alan Cox	:	Look up device on a retransmit - routes may
 *					change. Doesn't yet cope with MSS shrink right
 *					but it's a start!
 *		Marc Tamsky	:	Closing in closing fixes.
 *		Mike Shaver	:	RFC1122 verifications.
 *		Alan Cox	:	rcv_saddr errors.
 *		Alan Cox	:	Block double connect().
 *		Alan Cox	:	Small hooks for enSKIP.
 *		Alexey Kuznetsov:	Path MTU discovery.
 *		Alan Cox	:	Support soft errors.
 *		Alan Cox	:	Fix MTU discovery pathological case
 *					when the remote claims no mtu!
 *		Marc Tamsky	:	TCP_CLOSE fix.
 *		Colin (G3TNE)	:	Send a reset on syn ack replies in
 *					window but wrong (fixes NT lpd problems)
 *		Pedro Roque	:	Better TCP window handling, delayed ack.
 *		Joerg Reuter	:	No modification of locked buffers in
 *					tcp_do_retransmit()
 *		Eric Schenk	:	Changed receiver side silly window
 *					avoidance algorithm to BSD style
 *					algorithm. This doubles throughput
 *					against machines running Solaris,
 *					and seems to result in general
 *					improvement.
 *	Stefan Magdalinski	:	adjusted tcp_readable() to fix FIONREAD
 *	Willy Konynenberg	:	Transparent proxying support.
 *	Mike McLagan		:	Routing by source
 *		Keith Owens	:	Do proper merging with partial SKB's in
 *					tcp_do_sendmsg to avoid burstiness.
 *		Eric Schenk	:	Fix fast close down bug with
 *					shutdown() followed by close().
 *		Andi Kleen 	:	Make poll agree with SIGIO
 *	Salvatore Sanfilippo	:	Support SO_LINGER with linger == 1 and
 *					lingertime == 0 (RFC 793 ABORT Call)
 *	Hirokazu Takahashi	:	Use copy_from_user() instead of
 *					csum_and_copy_from_user() if possible.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or(at your option) any later version.
 *
 * Description of States:
 *
 *	TCP_SYN_SENT		sent a connection request, waiting for ack
 *
 *	TCP_SYN_RECV		received a connection request, sent ack,
 *				waiting for final ack in three-way handshake.
 *
 *	TCP_ESTABLISHED		connection established
 *
 *	TCP_FIN_WAIT1		our side has shutdown, waiting to complete
 *				transmission of remaining buffered data
 *
 *	TCP_FIN_WAIT2		all buffered data sent, waiting for remote
 *				to shutdown
 *
 *	TCP_CLOSING		both sides have shutdown but we still have
 *				data we have to finish sending
 *
 *	TCP_TIME_WAIT		timeout to catch resent junk before entering
 *				closed, can only be entered from FIN_WAIT2
 *				or CLOSING.  Required because the other end
 *				may not have gotten our last ACK causing it
 *				to retransmit the data packet (which we ignore)
 *
 *	TCP_CLOSE_WAIT		remote side has shutdown and is waiting for
 *				us to finish writing our data and to shutdown
 *				(we have to close() to move on to LAST_ACK)
 *
 *	TCP_LAST_ACK		out side has shutdown after remote has
 *				shutdown.  There may still be data in our
 *				buffer that we have to finish sending
 *
 *	TCP_CLOSE		socket is finished
 */

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#define pr_fmt(fmt) "TCP: " fmt

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#include <crypto/hash.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
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#include <linux/inet_diag.h>
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#include <linux/init.h>
#include <linux/fs.h>
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#include <linux/skbuff.h>
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#include <linux/scatterlist.h>
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#include <linux/splice.h>
#include <linux/net.h>
#include <linux/socket.h>
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#include <linux/random.h>
#include <linux/bootmem.h>
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#include <linux/highmem.h>
#include <linux/swap.h>
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#include <linux/cache.h>
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#include <linux/err.h>
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#include <linux/time.h>
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#include <linux/slab.h>
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#include <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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int sysctl_tcp_min_tso_segs __read_mostly = 2;

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int sysctl_tcp_autocorking __read_mostly = 1;

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struct percpu_counter tcp_orphan_count;
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EXPORT_SYMBOL_GPL(tcp_orphan_count);

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long sysctl_tcp_mem[3] __read_mostly;
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int sysctl_tcp_wmem[3] __read_mostly;
int sysctl_tcp_rmem[3] __read_mostly;
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EXPORT_SYMBOL(sysctl_tcp_mem);
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EXPORT_SYMBOL(sysctl_tcp_rmem);
EXPORT_SYMBOL(sysctl_tcp_wmem);

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

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

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

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	tp->reordering = sock_net(sk)->ipv4.sysctl_tcp_reordering;
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	tcp_assign_congestion_control(sk);
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	tp->tsoffset = 0;

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	sk->sk_state = TCP_CLOSE;

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

	icsk->icsk_sync_mss = tcp_sync_mss;

	sk->sk_sndbuf = sysctl_tcp_wmem[1];
	sk->sk_rcvbuf = sysctl_tcp_rmem[1];

	sk_sockets_allocated_inc(sk);
}
EXPORT_SYMBOL(tcp_init_sock);

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static void tcp_tx_timestamp(struct sock *sk, u16 tsflags, struct sk_buff *skb)
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{
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	if (tsflags && skb) {
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		struct skb_shared_info *shinfo = skb_shinfo(skb);
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		struct tcp_skb_cb *tcb = TCP_SKB_CB(skb);
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		sock_tx_timestamp(sk, tsflags, &shinfo->tx_flags);
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		if (tsflags & SOF_TIMESTAMPING_TX_ACK)
			tcb->txstamp_ack = 1;
		if (tsflags & SOF_TIMESTAMPING_TX_RECORD_MASK)
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			shinfo->tskey = TCP_SKB_CB(skb)->seq + skb->len - 1;
	}
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}

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/*
 *	Wait for a TCP event.
 *
 *	Note that we don't need to lock the socket, as the upper poll layers
 *	take care of normal races (between the test and the event) and we don't
 *	go look at any of the socket buffers directly.
 */
unsigned int tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
{
	unsigned int mask;
	struct sock *sk = sock->sk;
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	const struct tcp_sock *tp = tcp_sk(sk);
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	int state;
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	sock_rps_record_flow(sk);

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	sock_poll_wait(file, sk_sleep(sk), wait);
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	state = sk_state_load(sk);
	if (state == TCP_LISTEN)
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		return inet_csk_listen_poll(sk);
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	/* Socket is not locked. We are protected from async events
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	 * by poll logic and correct handling of state changes
	 * made by other threads is impossible in any case.
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	 */

	mask = 0;

	/*
	 * POLLHUP is certainly not done right. But poll() doesn't
	 * have a notion of HUP in just one direction, and for a
	 * socket the read side is more interesting.
	 *
	 * Some poll() documentation says that POLLHUP is incompatible
	 * with the POLLOUT/POLLWR flags, so somebody should check this
	 * all. But careful, it tends to be safer to return too many
	 * bits than too few, and you can easily break real applications
	 * if you don't tell them that something has hung up!
	 *
	 * Check-me.
	 *
	 * Check number 1. POLLHUP is _UNMASKABLE_ event (see UNIX98 and
	 * our fs/select.c). It means that after we received EOF,
	 * poll always returns immediately, making impossible poll() on write()
	 * in state CLOSE_WAIT. One solution is evident --- to set POLLHUP
	 * if and only if shutdown has been made in both directions.
	 * Actually, it is interesting to look how Solaris and DUX
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	 * solve this dilemma. I would prefer, if POLLHUP were maskable,
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	 * then we could set it on SND_SHUTDOWN. BTW examples given
	 * in Stevens' books assume exactly this behaviour, it explains
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	 * why POLLHUP is incompatible with POLLOUT.	--ANK
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	 *
	 * NOTE. Check for TCP_CLOSE is added. The goal is to prevent
	 * blocking on fresh not-connected or disconnected socket. --ANK
	 */
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	if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE)
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		mask |= POLLHUP;
	if (sk->sk_shutdown & RCV_SHUTDOWN)
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		mask |= POLLIN | POLLRDNORM | POLLRDHUP;
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	/* Connected or passive Fast Open socket? */
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	if (state != TCP_SYN_SENT &&
	    (state != TCP_SYN_RECV || tp->fastopen_rsk)) {
536 537 538 539 540
		int target = sock_rcvlowat(sk, 0, INT_MAX);

		if (tp->urg_seq == tp->copied_seq &&
		    !sock_flag(sk, SOCK_URGINLINE) &&
		    tp->urg_data)
541
			target++;
542 543

		if (tp->rcv_nxt - tp->copied_seq >= target)
L
Linus Torvalds 已提交
544 545 546
			mask |= POLLIN | POLLRDNORM;

		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
547
			if (sk_stream_is_writeable(sk)) {
L
Linus Torvalds 已提交
548 549
				mask |= POLLOUT | POLLWRNORM;
			} else {  /* send SIGIO later */
550
				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
551 552 553 554
				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);

				/* Race breaker. If space is freed after
				 * wspace test but before the flags are set,
555 556
				 * IO signal will be lost. Memory barrier
				 * pairs with the input side.
L
Linus Torvalds 已提交
557
				 */
558
				smp_mb__after_atomic();
559
				if (sk_stream_is_writeable(sk))
L
Linus Torvalds 已提交
560 561
					mask |= POLLOUT | POLLWRNORM;
			}
562 563
		} else
			mask |= POLLOUT | POLLWRNORM;
L
Linus Torvalds 已提交
564 565 566

		if (tp->urg_data & TCP_URG_VALID)
			mask |= POLLPRI;
567
	} else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
W
Wei Wang 已提交
568 569 570 571 572
		/* Active TCP fastopen socket with defer_connect
		 * Return POLLOUT so application can call write()
		 * in order for kernel to generate SYN+data
		 */
		mask |= POLLOUT | POLLWRNORM;
L
Linus Torvalds 已提交
573
	}
T
Tom Marshall 已提交
574 575
	/* This barrier is coupled with smp_wmb() in tcp_reset() */
	smp_rmb();
576
	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
T
Tom Marshall 已提交
577 578
		mask |= POLLERR;

L
Linus Torvalds 已提交
579 580
	return mask;
}
E
Eric Dumazet 已提交
581
EXPORT_SYMBOL(tcp_poll);
L
Linus Torvalds 已提交
582 583 584 585 586

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
587
	bool slow;
L
Linus Torvalds 已提交
588 589 590 591 592 593

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

E
Eric Dumazet 已提交
594
		slow = lock_sock_fast(sk);
595
		answ = tcp_inq(sk);
E
Eric Dumazet 已提交
596
		unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
597 598 599 600 601 602 603 604 605 606 607 608 609
		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;
610 611 612 613 614 615 616 617 618
	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
619 620
	default:
		return -ENOIOCTLCMD;
621
	}
L
Linus Torvalds 已提交
622 623 624

	return put_user(answ, (int __user *)arg);
}
E
Eric Dumazet 已提交
625
EXPORT_SYMBOL(tcp_ioctl);
L
Linus Torvalds 已提交
626 627 628

static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
{
E
Eric Dumazet 已提交
629
	TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
L
Linus Torvalds 已提交
630 631 632
	tp->pushed_seq = tp->write_seq;
}

E
Eric Dumazet 已提交
633
static inline bool forced_push(const struct tcp_sock *tp)
L
Linus Torvalds 已提交
634 635 636 637
{
	return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
}

638
static void skb_entail(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
639
{
640
	struct tcp_sock *tp = tcp_sk(sk);
641 642 643 644
	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
645
	tcb->tcp_flags = TCPHDR_ACK;
646
	tcb->sacked  = 0;
647
	__skb_header_release(skb);
648
	tcp_add_write_queue_tail(sk, skb);
649 650
	sk->sk_wmem_queued += skb->truesize;
	sk_mem_charge(sk, skb->truesize);
651
	if (tp->nonagle & TCP_NAGLE_PUSH)
652
		tp->nonagle &= ~TCP_NAGLE_PUSH;
653 654

	tcp_slow_start_after_idle_check(sk);
L
Linus Torvalds 已提交
655 656
}

657
static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
L
Linus Torvalds 已提交
658
{
I
Ilpo Järvinen 已提交
659
	if (flags & MSG_OOB)
L
Linus Torvalds 已提交
660 661 662
		tp->snd_up = tp->write_seq;
}

E
Eric Dumazet 已提交
663
/* If a not yet filled skb is pushed, do not send it if
664
 * we have data packets in Qdisc or NIC queues :
E
Eric Dumazet 已提交
665 666 667 668
 * 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
669 670 671
 * 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
672 673 674
 */
static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
				int size_goal)
L
Linus Torvalds 已提交
675
{
E
Eric Dumazet 已提交
676 677
	return skb->len < size_goal &&
	       sysctl_tcp_autocorking &&
678
	       skb != tcp_write_queue_head(sk) &&
679
	       refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
E
Eric Dumazet 已提交
680 681 682 683 684 685 686
}

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;
687

E
Eric Dumazet 已提交
688 689
	if (!tcp_send_head(sk))
		return;
690

E
Eric Dumazet 已提交
691 692 693 694 695 696 697 698 699
	skb = tcp_write_queue_tail(sk);
	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 */
700
		if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
E
Eric Dumazet 已提交
701
			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
702
			set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
E
Eric Dumazet 已提交
703
		}
704 705 706
		/* It is possible TX completion already happened
		 * before we set TSQ_THROTTLED.
		 */
707
		if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
708
			return;
L
Linus Torvalds 已提交
709
	}
E
Eric Dumazet 已提交
710 711 712 713 714

	if (flags & MSG_MORE)
		nonagle = TCP_NAGLE_CORK;

	__tcp_push_pending_frames(sk, mss_now, nonagle);
L
Linus Torvalds 已提交
715 716
}

717 718
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
719 720
{
	struct tcp_splice_state *tss = rd_desc->arg.data;
721
	int ret;
J
Jens Axboe 已提交
722

723
	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
A
Al Viro 已提交
724
			      min(rd_desc->count, len), tss->flags);
725 726 727
	if (ret > 0)
		rd_desc->count -= ret;
	return ret;
J
Jens Axboe 已提交
728 729 730 731 732 733 734
}

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,
735
		.count	  = tss->len,
J
Jens Axboe 已提交
736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766
	};

	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;

767
	sock_rps_record_flow(sk);
J
Jens Axboe 已提交
768 769 770 771 772 773 774 775 776 777
	/*
	 * We can't seek on a socket input
	 */
	if (unlikely(*ppos))
		return -ESPIPE;

	ret = spliced = 0;

	lock_sock(sk);

778
	timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
J
Jens Axboe 已提交
779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806
	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;
			}
807 808 809 810 811 812
			/* 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;
813
			sk_wait_data(sk, &timeo, NULL);
J
Jens Axboe 已提交
814 815 816 817 818 819 820 821 822
			if (signal_pending(current)) {
				ret = sock_intr_errno(timeo);
				break;
			}
			continue;
		}
		tss.len -= ret;
		spliced += ret;

823 824
		if (!timeo)
			break;
J
Jens Axboe 已提交
825 826 827 828
		release_sock(sk);
		lock_sock(sk);

		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
829
		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
J
Jens Axboe 已提交
830 831 832 833 834 835 836 837 838 839 840
		    signal_pending(current))
			break;
	}

	release_sock(sk);

	if (spliced)
		return spliced;

	return ret;
}
E
Eric Dumazet 已提交
841
EXPORT_SYMBOL(tcp_splice_read);
J
Jens Axboe 已提交
842

843 844
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
				    bool force_schedule)
845 846 847 848 849 850
{
	struct sk_buff *skb;

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

851 852 853
	if (unlikely(tcp_under_memory_pressure(sk)))
		sk_mem_reclaim_partial(sk);

854
	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
855
	if (likely(skb)) {
856
		bool mem_scheduled;
857

858 859
		if (force_schedule) {
			mem_scheduled = true;
860 861
			sk_forced_mem_schedule(sk, skb->truesize);
		} else {
862
			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
863
		}
864
		if (likely(mem_scheduled)) {
865
			skb_reserve(skb, sk->sk_prot->max_header);
866 867 868 869
			/*
			 * Make sure that we have exactly size bytes
			 * available to the caller, no more, no less.
			 */
E
Eric Dumazet 已提交
870
			skb->reserved_tailroom = skb->end - skb->tail - size;
871 872 873 874
			return skb;
		}
		__kfree_skb(skb);
	} else {
875
		sk->sk_prot->enter_memory_pressure(sk);
876 877 878 879 880
		sk_stream_moderate_sndbuf(sk);
	}
	return NULL;
}

I
Ilpo Järvinen 已提交
881 882 883 884
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
				       int large_allowed)
{
	struct tcp_sock *tp = tcp_sk(sk);
885
	u32 new_size_goal, size_goal;
E
Eric Dumazet 已提交
886 887 888 889

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

890 891
	/* 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
892 893 894 895 896 897 898 899 900
	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
901 902
	}

E
Eric Dumazet 已提交
903
	return max(size_goal, mss_now);
I
Ilpo Järvinen 已提交
904 905 906 907 908 909 910 911 912 913 914 915
}

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;
}

916 917
ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
			 size_t size, int flags)
L
Linus Torvalds 已提交
918 919
{
	struct tcp_sock *tp = tcp_sk(sk);
920
	int mss_now, size_goal;
L
Linus Torvalds 已提交
921 922 923 924
	int err;
	ssize_t copied;
	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

925 926 927 928 929 930
	/* 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)) {
931 932
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
933
			goto out_err;
934
	}
L
Linus Torvalds 已提交
935

936
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
937

I
Ilpo Järvinen 已提交
938
	mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
939 940 941 942
	copied = 0;

	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
943
		goto out_err;
L
Linus Torvalds 已提交
944

945
	while (size > 0) {
946
		struct sk_buff *skb = tcp_write_queue_tail(sk);
947 948
		int copy, i;
		bool can_coalesce;
L
Linus Torvalds 已提交
949

950 951
		if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0 ||
		    !tcp_skb_can_collapse_to(skb)) {
L
Linus Torvalds 已提交
952 953 954 955
new_segment:
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;

956 957
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
						  skb_queue_empty(&sk->sk_write_queue));
L
Linus Torvalds 已提交
958 959 960
			if (!skb)
				goto wait_for_memory;

961
			skb_entail(sk, skb);
962
			copy = size_goal;
L
Linus Torvalds 已提交
963 964 965 966 967 968 969
		}

		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
970
		if (!can_coalesce && i >= sysctl_max_skb_frags) {
L
Linus Torvalds 已提交
971 972 973
			tcp_mark_push(tp, skb);
			goto new_segment;
		}
974
		if (!sk_wmem_schedule(sk, copy))
L
Linus Torvalds 已提交
975
			goto wait_for_memory;
976

L
Linus Torvalds 已提交
977
		if (can_coalesce) {
E
Eric Dumazet 已提交
978
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
L
Linus Torvalds 已提交
979 980 981 982
		} else {
			get_page(page);
			skb_fill_page_desc(skb, i, page, offset, copy);
		}
983
		skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
984

L
Linus Torvalds 已提交
985 986 987 988
		skb->len += copy;
		skb->data_len += copy;
		skb->truesize += copy;
		sk->sk_wmem_queued += copy;
989
		sk_mem_charge(sk, copy);
990
		skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
991 992
		tp->write_seq += copy;
		TCP_SKB_CB(skb)->end_seq += copy;
993
		tcp_skb_pcount_set(skb, 0);
L
Linus Torvalds 已提交
994 995

		if (!copied)
E
Eric Dumazet 已提交
996
			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
L
Linus Torvalds 已提交
997 998

		copied += copy;
999
		offset += copy;
1000
		size -= copy;
1001
		if (!size)
L
Linus Torvalds 已提交
1002 1003
			goto out;

1004
		if (skb->len < size_goal || (flags & MSG_OOB))
L
Linus Torvalds 已提交
1005 1006 1007 1008
			continue;

		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
1009
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1010
		} else if (skb == tcp_send_head(sk))
L
Linus Torvalds 已提交
1011 1012 1013 1014 1015 1016
			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
1017 1018
		tcp_push(sk, flags & ~MSG_MORE, mss_now,
			 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1019

1020 1021
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
1022 1023
			goto do_error;

I
Ilpo Järvinen 已提交
1024
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1025 1026 1027
	}

out:
1028 1029 1030 1031 1032
	if (copied) {
		tcp_tx_timestamp(sk, sk->sk_tsflags, tcp_write_queue_tail(sk));
		if (!(flags & MSG_SENDPAGE_NOTLAST))
			tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
	}
L
Linus Torvalds 已提交
1033 1034 1035 1036 1037 1038
	return copied;

do_error:
	if (copied)
		goto out;
out_err:
1039
	/* make sure we wake any epoll edge trigger waiter */
1040 1041
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1042
		sk->sk_write_space(sk);
1043 1044
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1045 1046
	return sk_stream_error(sk, flags, err);
}
1047
EXPORT_SYMBOL_GPL(do_tcp_sendpages);
L
Linus Torvalds 已提交
1048

1049 1050
int tcp_sendpage(struct sock *sk, struct page *page, int offset,
		 size_t size, int flags)
L
Linus Torvalds 已提交
1051 1052 1053 1054
{
	ssize_t res;

	if (!(sk->sk_route_caps & NETIF_F_SG) ||
1055
	    !sk_check_csum_caps(sk))
1056 1057
		return sock_no_sendpage(sk->sk_socket, page, offset, size,
					flags);
L
Linus Torvalds 已提交
1058 1059

	lock_sock(sk);
1060 1061 1062

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

1063
	res = do_tcp_sendpages(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1064 1065 1066
	release_sock(sk);
	return res;
}
E
Eric Dumazet 已提交
1067
EXPORT_SYMBOL(tcp_sendpage);
L
Linus Torvalds 已提交
1068

1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086
/* Do not bother using a page frag for very small frames.
 * But use this heuristic only for the first skb in write queue.
 *
 * Having no payload in skb->head allows better SACK shifting
 * in tcp_shift_skb_data(), reducing sack/rack overhead, because
 * write queue has less skbs.
 * Each skb can hold up to MAX_SKB_FRAGS * 32Kbytes, or ~0.5 MB.
 * This also speeds up tso_fragment(), since it wont fallback
 * to tcp_fragment().
 */
static int linear_payload_sz(bool first_skb)
{
	if (first_skb)
		return SKB_WITH_OVERHEAD(2048 - MAX_TCP_HEADER);
	return 0;
}

static int select_size(const struct sock *sk, bool sg, bool first_skb)
L
Linus Torvalds 已提交
1087
{
1088
	const struct tcp_sock *tp = tcp_sk(sk);
1089
	int tmp = tp->mss_cache;
L
Linus Torvalds 已提交
1090

K
Krishna Kumar 已提交
1091
	if (sg) {
1092
		if (sk_can_gso(sk)) {
1093
			tmp = linear_payload_sz(first_skb);
1094
		} else {
1095 1096 1097 1098 1099 1100 1101
			int pgbreak = SKB_MAX_HEAD(MAX_TCP_HEADER);

			if (tmp >= pgbreak &&
			    tmp <= pgbreak + (MAX_SKB_FRAGS - 1) * PAGE_SIZE)
				tmp = pgbreak;
		}
	}
L
Linus Torvalds 已提交
1102 1103 1104 1105

	return tmp;
}

1106 1107
void tcp_free_fastopen_req(struct tcp_sock *tp)
{
1108
	if (tp->fastopen_req) {
1109 1110 1111 1112 1113
		kfree(tp->fastopen_req);
		tp->fastopen_req = NULL;
	}
}

1114 1115
static int tcp_sendmsg_fastopen(struct sock *sk, struct msghdr *msg,
				int *copied, size_t size)
1116 1117
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Wei Wang 已提交
1118
	struct inet_sock *inet = inet_sk(sk);
1119
	struct sockaddr *uaddr = msg->msg_name;
1120 1121
	int err, flags;

1122 1123 1124
	if (!(sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
	    (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
	     uaddr->sa_family == AF_UNSPEC))
1125
		return -EOPNOTSUPP;
1126
	if (tp->fastopen_req)
1127 1128 1129 1130
		return -EALREADY; /* Another Fast Open is in progress */

	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
				   sk->sk_allocation);
1131
	if (unlikely(!tp->fastopen_req))
1132 1133
		return -ENOBUFS;
	tp->fastopen_req->data = msg;
1134
	tp->fastopen_req->size = size;
1135

W
Wei Wang 已提交
1136 1137 1138 1139 1140 1141 1142 1143 1144
	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;
		}
	}
1145
	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1146
	err = __inet_stream_connect(sk->sk_socket, uaddr,
1147
				    msg->msg_namelen, flags, 1);
1148 1149 1150 1151 1152 1153 1154 1155
	/* 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;
	}
1156 1157 1158
	return err;
}

1159
int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
L
Linus Torvalds 已提交
1160 1161 1162
{
	struct tcp_sock *tp = tcp_sk(sk);
	struct sk_buff *skb;
1163
	struct sockcm_cookie sockc;
1164 1165
	int flags, err, copied = 0;
	int mss_now = 0, size_goal, copied_syn = 0;
1166
	bool process_backlog = false;
1167
	bool sg;
L
Linus Torvalds 已提交
1168 1169 1170 1171 1172
	long timeo;

	lock_sock(sk);

	flags = msg->msg_flags;
W
Wei Wang 已提交
1173
	if (unlikely(flags & MSG_FASTOPEN || inet_sk(sk)->defer_connect)) {
1174
		err = tcp_sendmsg_fastopen(sk, msg, &copied_syn, size);
1175 1176 1177 1178 1179 1180
		if (err == -EINPROGRESS && copied_syn > 0)
			goto out;
		else if (err)
			goto out_err;
	}

L
Linus Torvalds 已提交
1181 1182
	timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

1183 1184
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1185 1186 1187 1188 1189 1190
	/* 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)) {
1191 1192
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
1193
			goto do_error;
1194
	}
L
Linus Torvalds 已提交
1195

P
Pavel Emelyanov 已提交
1196 1197 1198
	if (unlikely(tp->repair)) {
		if (tp->repair_queue == TCP_RECV_QUEUE) {
			copied = tcp_send_rcvq(sk, msg, size);
1199
			goto out_nopush;
P
Pavel Emelyanov 已提交
1200 1201 1202 1203 1204 1205 1206 1207 1208
		}

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

		/* 'common' sending to sendq */
	}

1209 1210 1211 1212 1213 1214 1215 1216 1217
	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
1218
	/* This should be in poll */
1219
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
1220 1221 1222 1223

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

1224 1225 1226
restart:
	mss_now = tcp_send_mss(sk, &size_goal, flags);

L
Linus Torvalds 已提交
1227 1228
	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
1229
		goto do_error;
L
Linus Torvalds 已提交
1230

1231
	sg = !!(sk->sk_route_caps & NETIF_F_SG);
K
Krishna Kumar 已提交
1232

A
Al Viro 已提交
1233
	while (msg_data_left(msg)) {
1234 1235
		int copy = 0;
		int max = size_goal;
L
Linus Torvalds 已提交
1236

1237 1238 1239 1240 1241
		skb = tcp_write_queue_tail(sk);
		if (tcp_send_head(sk)) {
			if (skb->ip_summed == CHECKSUM_NONE)
				max = mss_now;
			copy = max - skb->len;
1242
		}
L
Linus Torvalds 已提交
1243

1244
		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1245 1246
			bool first_skb;

L
Linus Torvalds 已提交
1247
new_segment:
1248 1249 1250 1251 1252
			/* 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
1253

1254 1255
			if (process_backlog && sk_flush_backlog(sk)) {
				process_backlog = false;
1256
				goto restart;
1257
			}
1258
			first_skb = skb_queue_empty(&sk->sk_write_queue);
1259
			skb = sk_stream_alloc_skb(sk,
1260
						  select_size(sk, sg, first_skb),
1261
						  sk->sk_allocation,
1262
						  first_skb);
1263 1264
			if (!skb)
				goto wait_for_memory;
L
Linus Torvalds 已提交
1265

1266
			process_backlog = true;
1267 1268 1269
			/*
			 * Check whether we can use HW checksum.
			 */
1270
			if (sk_check_csum_caps(sk))
1271
				skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1272

1273 1274 1275
			skb_entail(sk, skb);
			copy = size_goal;
			max = size_goal;
1276

1277 1278 1279 1280 1281 1282 1283
			/* 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
1284

1285
		/* Try to append data to the end of skb. */
A
Al Viro 已提交
1286 1287
		if (copy > msg_data_left(msg))
			copy = msg_data_left(msg);
1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302

		/* Where to copy to? */
		if (skb_availroom(skb) > 0) {
			/* We have some space in skb head. Superb! */
			copy = min_t(int, copy, skb_availroom(skb));
			err = skb_add_data_nocache(sk, skb, &msg->msg_iter, copy);
			if (err)
				goto do_fault;
		} else {
			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;
1303

1304 1305
			if (!skb_can_coalesce(skb, i, pfrag->page,
					      pfrag->offset)) {
1306
				if (i >= sysctl_max_skb_frags || !sg) {
1307 1308
					tcp_mark_push(tp, skb);
					goto new_segment;
L
Linus Torvalds 已提交
1309
				}
1310
				merge = false;
L
Linus Torvalds 已提交
1311 1312
			}

1313 1314 1315 1316
			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
1317

1318 1319 1320 1321 1322 1323
			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
1324

1325 1326 1327 1328 1329 1330
			/* 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);
1331
				page_ref_inc(pfrag->page);
1332
			}
1333 1334 1335 1336 1337 1338 1339 1340 1341
			pfrag->offset += copy;
		}

		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
1342

1343
		copied += copy;
A
Al Viro 已提交
1344
		if (!msg_data_left(msg)) {
1345 1346
			if (unlikely(flags & MSG_EOR))
				TCP_SKB_CB(skb)->eor = 1;
1347 1348
			goto out;
		}
L
Linus Torvalds 已提交
1349

1350
		if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
L
Linus Torvalds 已提交
1351 1352
			continue;

1353 1354 1355 1356 1357 1358 1359
		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
1360
wait_for_sndbuf:
1361
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
L
Linus Torvalds 已提交
1362
wait_for_memory:
1363 1364 1365
		if (copied)
			tcp_push(sk, flags & ~MSG_MORE, mss_now,
				 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1366

1367 1368
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
1369
			goto do_error;
L
Linus Torvalds 已提交
1370

1371
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1372 1373 1374
	}

out:
1375 1376
	if (copied) {
		tcp_tx_timestamp(sk, sockc.tsflags, tcp_write_queue_tail(sk));
E
Eric Dumazet 已提交
1377
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1378
	}
1379
out_nopush:
L
Linus Torvalds 已提交
1380
	release_sock(sk);
1381
	return copied + copied_syn;
L
Linus Torvalds 已提交
1382 1383 1384

do_fault:
	if (!skb->len) {
1385 1386 1387 1388 1389
		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);
1390
		sk_wmem_free_skb(sk, skb);
L
Linus Torvalds 已提交
1391 1392 1393
	}

do_error:
1394
	if (copied + copied_syn)
L
Linus Torvalds 已提交
1395 1396 1397
		goto out;
out_err:
	err = sk_stream_error(sk, flags, err);
1398
	/* make sure we wake any epoll edge trigger waiter */
1399 1400
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1401
		sk->sk_write_space(sk);
1402 1403
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1404 1405 1406
	release_sock(sk);
	return err;
}
E
Eric Dumazet 已提交
1407
EXPORT_SYMBOL(tcp_sendmsg);
L
Linus Torvalds 已提交
1408 1409 1410 1411 1412 1413

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

1414
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
L
Linus Torvalds 已提交
1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437
{
	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
1438
				err = memcpy_to_msg(msg, &c, 1);
L
Linus Torvalds 已提交
1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457
			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
1458 1459 1460 1461 1462 1463 1464 1465
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 */

	skb_queue_walk(&sk->sk_write_queue, skb) {
1466
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
P
Pavel Emelyanov 已提交
1467 1468 1469 1470 1471 1472 1473 1474 1475
		if (err)
			break;

		copied += skb->len;
	}

	return err ?: copied;
}

L
Linus Torvalds 已提交
1476 1477 1478 1479 1480 1481
/* 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.
 */
1482
static void tcp_cleanup_rbuf(struct sock *sk, int copied)
L
Linus Torvalds 已提交
1483 1484
{
	struct tcp_sock *tp = tcp_sk(sk);
E
Eric Dumazet 已提交
1485
	bool time_to_ack = false;
L
Linus Torvalds 已提交
1486 1487 1488

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

1489
	WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
J
Joe Perches 已提交
1490
	     "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1491
	     tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
L
Linus Torvalds 已提交
1492

1493 1494
	if (inet_csk_ack_scheduled(sk)) {
		const struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1495 1496
		   /* Delayed ACKs frequently hit locked sockets during bulk
		    * receive. */
1497
		if (icsk->icsk_ack.blocked ||
L
Linus Torvalds 已提交
1498
		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
1499
		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
L
Linus Torvalds 已提交
1500 1501 1502 1503 1504 1505
		    /*
		     * 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.
		     */
1506 1507 1508 1509 1510
		    (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
1511
			time_to_ack = true;
L
Linus Torvalds 已提交
1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532
	}

	/* 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
1533
				time_to_ack = true;
L
Linus Torvalds 已提交
1534 1535 1536 1537 1538 1539
		}
	}
	if (time_to_ack)
		tcp_send_ack(sk);
}

1540
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
L
Linus Torvalds 已提交
1541 1542 1543 1544
{
	struct sk_buff *skb;
	u32 offset;

1545
	while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
L
Linus Torvalds 已提交
1546
		offset = seq - TCP_SKB_CB(skb)->seq;
1547 1548
		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
1549
			offset--;
1550
		}
1551
		if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
L
Linus Torvalds 已提交
1552 1553 1554
			*off = offset;
			return skb;
		}
1555 1556 1557 1558
		/* 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
1559
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587
	}
	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) {
1588 1589
			int used;
			size_t len;
L
Linus Torvalds 已提交
1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600

			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);
1601
			if (used <= 0) {
1602 1603 1604 1605
				if (!copied)
					copied = used;
				break;
			} else if (used <= len) {
L
Linus Torvalds 已提交
1606 1607 1608 1609
				seq += used;
				copied += used;
				offset += used;
			}
1610
			/* If recv_actor drops the lock (e.g. TCP splice
1611 1612 1613 1614
			 * receive) the skb pointer might be invalid when
			 * getting here: tcp_collapse might have deleted it
			 * while aggregating skbs from the socket queue.
			 */
1615 1616
			skb = tcp_recv_skb(sk, seq - 1, &offset);
			if (!skb)
L
Linus Torvalds 已提交
1617
				break;
1618 1619 1620 1621 1622
			/* 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
1623
		}
1624
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
D
Dan Williams 已提交
1625
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1626 1627 1628
			++seq;
			break;
		}
D
Dan Williams 已提交
1629
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1630 1631
		if (!desc->count)
			break;
1632
		tp->copied_seq = seq;
L
Linus Torvalds 已提交
1633 1634 1635 1636 1637 1638
	}
	tp->copied_seq = seq;

	tcp_rcv_space_adjust(sk);

	/* Clean up data we have read: This will do ACK frames. */
1639 1640
	if (copied > 0) {
		tcp_recv_skb(sk, seq, &offset);
1641
		tcp_cleanup_rbuf(sk, copied);
1642
	}
L
Linus Torvalds 已提交
1643 1644
	return copied;
}
E
Eric Dumazet 已提交
1645
EXPORT_SYMBOL(tcp_read_sock);
L
Linus Torvalds 已提交
1646

1647 1648 1649 1650 1651 1652
int tcp_peek_len(struct socket *sock)
{
	return tcp_inq(sock->sk);
}
EXPORT_SYMBOL(tcp_peek_len);

L
Linus Torvalds 已提交
1653 1654 1655 1656 1657 1658 1659 1660
/*
 *	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.
 */

1661 1662
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
1663 1664 1665 1666 1667 1668 1669 1670 1671
{
	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;
1672
	struct sk_buff *skb, *last;
I
Ilpo Järvinen 已提交
1673
	u32 urg_hole = 0;
L
Linus Torvalds 已提交
1674

1675
	if (unlikely(flags & MSG_ERRQUEUE))
1676
		return inet_recv_error(sk, msg, len, addr_len);
1677

1678 1679 1680
	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
	    (sk->sk_state == TCP_ESTABLISHED))
		sk_busy_loop(sk, nonblock);
1681

L
Linus Torvalds 已提交
1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693
	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
1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708
	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
1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731
	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. */

1732
		last = skb_peek_tail(&sk->sk_receive_queue);
1733
		skb_queue_walk(&sk->sk_receive_queue, skb) {
1734
			last = skb;
L
Linus Torvalds 已提交
1735 1736 1737
			/* Now that we have two receive queues this
			 * shouldn't happen.
			 */
1738
			if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
J
Joe Perches 已提交
1739 1740 1741
				 "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
1742
				break;
1743

L
Linus Torvalds 已提交
1744
			offset = *seq - TCP_SKB_CB(skb)->seq;
1745 1746
			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
1747
				offset--;
1748
			}
L
Linus Torvalds 已提交
1749 1750
			if (offset < skb->len)
				goto found_ok_skb;
1751
			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1752
				goto found_fin_ok;
J
Joe Perches 已提交
1753 1754 1755
			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);
1756
		}
L
Linus Torvalds 已提交
1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767

		/* 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 ||
1768
			    signal_pending(current))
L
Linus Torvalds 已提交
1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803
				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;
			}
		}

1804
		tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1805 1806 1807 1808 1809

		if (copied >= target) {
			/* Do not sleep, just process backlog. */
			release_sock(sk);
			lock_sock(sk);
1810 1811 1812
		} else {
			sk_wait_data(sk, &timeo, last);
		}
L
Linus Torvalds 已提交
1813

I
Ilpo Järvinen 已提交
1814 1815
		if ((flags & MSG_PEEK) &&
		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
1816 1817 1818
			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
1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835
			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
1836
						urg_hole++;
L
Linus Torvalds 已提交
1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847
						offset++;
						used--;
						if (!used)
							goto skip_copy;
					}
				} else
					used = urg_offset;
			}
		}

		if (!(flags & MSG_TRUNC)) {
1848
			err = skb_copy_datagram_msg(skb, offset, msg, used);
D
Dan Williams 已提交
1849 1850 1851 1852 1853
			if (err) {
				/* Exception. Bailout! */
				if (!copied)
					copied = -EFAULT;
				break;
L
Linus Torvalds 已提交
1854 1855 1856 1857 1858 1859 1860 1861 1862 1863
			}
		}

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

		tcp_rcv_space_adjust(sk);

skip_copy:
F
Florian Westphal 已提交
1864
		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq))
L
Linus Torvalds 已提交
1865 1866 1867 1868
			tp->urg_data = 0;
		if (used + offset < skb->len)
			continue;

1869
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1870
			goto found_fin_ok;
D
Dan Williams 已提交
1871 1872
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1873 1874 1875 1876 1877
		continue;

	found_fin_ok:
		/* Process the FIN. */
		++*seq;
D
Dan Williams 已提交
1878 1879
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1880 1881 1882 1883 1884 1885 1886 1887
		break;
	} while (len > 0);

	/* According to UNIX98, msg_name/msg_namelen are ignored
	 * on connected socket. I was just happy when found this 8) --ANK
	 */

	/* Clean up data we have read: This will do ACK frames. */
1888
	tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1889 1890 1891 1892 1893 1894 1895 1896 1897

	release_sock(sk);
	return copied;

out:
	release_sock(sk);
	return err;

recv_urg:
1898
	err = tcp_recv_urg(sk, msg, len, flags);
L
Linus Torvalds 已提交
1899
	goto out;
P
Pavel Emelyanov 已提交
1900 1901 1902 1903

recv_sndq:
	err = tcp_peek_sndq(sk, msg, len);
	goto out;
L
Linus Torvalds 已提交
1904
}
E
Eric Dumazet 已提交
1905
EXPORT_SYMBOL(tcp_recvmsg);
L
Linus Torvalds 已提交
1906

I
Ilpo Järvinen 已提交
1907 1908 1909 1910 1911 1912 1913
void tcp_set_state(struct sock *sk, int state)
{
	int oldstate = sk->sk_state;

	switch (state) {
	case TCP_ESTABLISHED:
		if (oldstate != TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
1914
			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
1915 1916 1917 1918
		break;

	case TCP_CLOSE:
		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
1919
			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
I
Ilpo Järvinen 已提交
1920 1921 1922 1923

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
1924
			inet_put_port(sk);
I
Ilpo Järvinen 已提交
1925 1926
		/* fall through */
	default:
1927
		if (oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
1928
			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
1929 1930 1931 1932 1933
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
1934
	sk_state_store(sk, state);
I
Ilpo Järvinen 已提交
1935 1936

#ifdef STATE_TRACE
1937
	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
I
Ilpo Järvinen 已提交
1938 1939 1940 1941
#endif
}
EXPORT_SYMBOL_GPL(tcp_set_state);

L
Linus Torvalds 已提交
1942 1943 1944 1945 1946 1947 1948
/*
 *	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.
 */

1949
static const unsigned char new_state[16] = {
L
Linus Torvalds 已提交
1950
  /* current state:        new state:      action:	*/
1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963
  [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
1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977
};

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
1978
 *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
L
Linus Torvalds 已提交
1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
 */

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
1999
EXPORT_SYMBOL(tcp_shutdown);
L
Linus Torvalds 已提交
2000

A
Arun Sharma 已提交
2001 2002 2003 2004 2005 2006 2007
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);

2008 2009 2010 2011
	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
2012 2013 2014
	return too_many_orphans || out_of_socket_memory;
}

L
Linus Torvalds 已提交
2015 2016 2017 2018
void tcp_close(struct sock *sk, long timeout)
{
	struct sk_buff *skb;
	int data_was_unread = 0;
H
Herbert Xu 已提交
2019
	int state;
L
Linus Torvalds 已提交
2020 2021 2022 2023 2024 2025 2026 2027

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

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

		/* Special case. */
2028
		inet_csk_listen_stop(sk);
L
Linus Torvalds 已提交
2029 2030 2031 2032 2033 2034 2035 2036 2037

		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) {
2038 2039 2040 2041
		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
2042 2043 2044 2045
		data_was_unread += len;
		__kfree_skb(skb);
	}

2046
	sk_mem_reclaim(sk);
L
Linus Torvalds 已提交
2047

2048 2049 2050 2051
	/* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
	if (sk->sk_state == TCP_CLOSE)
		goto adjudge_to_death;

2052 2053 2054 2055 2056 2057
	/* 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
2058
	 */
P
Pavel Emelyanov 已提交
2059 2060 2061
	if (unlikely(tcp_sk(sk)->repair)) {
		sk->sk_prot->disconnect(sk, 0);
	} else if (data_was_unread) {
L
Linus Torvalds 已提交
2062
		/* Unread data was tossed, zap the connection. */
2063
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
L
Linus Torvalds 已提交
2064
		tcp_set_state(sk, TCP_CLOSE);
2065
		tcp_send_active_reset(sk, sk->sk_allocation);
L
Linus Torvalds 已提交
2066 2067 2068
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
2069
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
L
Linus Torvalds 已提交
2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094
	} 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
2095 2096 2097 2098
		 * 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
2099 2100 2101 2102 2103 2104 2105
		 */
		tcp_send_fin(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
H
Herbert Xu 已提交
2106 2107 2108 2109
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

L
Linus Torvalds 已提交
2110 2111 2112 2113 2114
	/* 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
2115
	 *  to finish close. No need to check for user refs.
L
Linus Torvalds 已提交
2116 2117 2118
	 */
	local_bh_disable();
	bh_lock_sock(sk);
2119
	WARN_ON(sock_owned_by_user(sk));
L
Linus Torvalds 已提交
2120

H
Herbert Xu 已提交
2121 2122
	percpu_counter_inc(sk->sk_prot->orphan_count);

H
Herbert Xu 已提交
2123 2124 2125
	/* 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
2126 2127 2128 2129

	/*	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.
2130
	 *	We use a 1 minute timeout (about the same as BSD) then kill
L
Linus Torvalds 已提交
2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145
	 *	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);
2146
			__NET_INC_STATS(sock_net(sk),
2147
					LINUX_MIB_TCPABORTONLINGER);
L
Linus Torvalds 已提交
2148
		} else {
2149
			const int tmo = tcp_fin_time(sk);
L
Linus Torvalds 已提交
2150 2151

			if (tmo > TCP_TIMEWAIT_LEN) {
2152 2153
				inet_csk_reset_keepalive_timer(sk,
						tmo - TCP_TIMEWAIT_LEN);
L
Linus Torvalds 已提交
2154 2155 2156 2157 2158 2159 2160
			} else {
				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
				goto out;
			}
		}
	}
	if (sk->sk_state != TCP_CLOSE) {
2161
		sk_mem_reclaim(sk);
A
Arun Sharma 已提交
2162
		if (tcp_check_oom(sk, 0)) {
L
Linus Torvalds 已提交
2163 2164
			tcp_set_state(sk, TCP_CLOSE);
			tcp_send_active_reset(sk, GFP_ATOMIC);
2165
			__NET_INC_STATS(sock_net(sk),
2166
					LINUX_MIB_TCPABORTONMEMORY);
L
Linus Torvalds 已提交
2167 2168 2169
		}
	}

2170 2171 2172 2173 2174 2175
	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.
		 */
2176
		if (req)
2177
			reqsk_fastopen_remove(sk, req, false);
2178
		inet_csk_destroy_sock(sk);
2179
	}
L
Linus Torvalds 已提交
2180 2181 2182 2183 2184 2185 2186
	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}
E
Eric Dumazet 已提交
2187
EXPORT_SYMBOL(tcp_close);
L
Linus Torvalds 已提交
2188 2189 2190

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

E
Eric Dumazet 已提交
2191
static inline bool tcp_need_reset(int state)
L
Linus Torvalds 已提交
2192 2193 2194 2195 2196 2197 2198 2199 2200
{
	return (1 << state) &
	       (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT | TCPF_FIN_WAIT1 |
		TCPF_FIN_WAIT2 | TCPF_SYN_RECV);
}

int tcp_disconnect(struct sock *sk, int flags)
{
	struct inet_sock *inet = inet_sk(sk);
2201
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2202 2203 2204 2205 2206 2207 2208 2209 2210
	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) {
2211
		inet_csk_listen_stop(sk);
P
Pavel Emelyanov 已提交
2212 2213
	} else if (unlikely(tp->repair)) {
		sk->sk_err = ECONNABORTED;
L
Linus Torvalds 已提交
2214 2215 2216
	} 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
2217
		/* The last check adjusts for discrepancy of Linux wrt. RFC
L
Linus Torvalds 已提交
2218 2219 2220 2221 2222 2223 2224 2225 2226
		 * 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);
2227
	tcp_write_queue_purge(sk);
2228
	tcp_fastopen_active_disable_ofo_check(sk);
2229
	skb_rbtree_purge(&tp->out_of_order_queue);
L
Linus Torvalds 已提交
2230

E
Eric Dumazet 已提交
2231
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
2232 2233 2234 2235 2236 2237

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

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);
2238
	tp->srtt_us = 0;
2239 2240
	tp->write_seq += tp->max_window + 2;
	if (tp->write_seq == 0)
L
Linus Torvalds 已提交
2241
		tp->write_seq = 1;
2242
	icsk->icsk_backoff = 0;
L
Linus Torvalds 已提交
2243
	tp->snd_cwnd = 2;
2244
	icsk->icsk_probes_out = 0;
L
Linus Torvalds 已提交
2245
	tp->packets_out = 0;
I
Ilpo Järvinen 已提交
2246
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
L
Linus Torvalds 已提交
2247
	tp->snd_cwnd_cnt = 0;
2248
	tp->window_clamp = 0;
2249
	tcp_set_ca_state(sk, TCP_CA_Open);
L
Linus Torvalds 已提交
2250
	tcp_clear_retrans(tp);
2251
	inet_csk_delack_init(sk);
2252 2253 2254 2255
	/* 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;
2256
	tcp_init_send_head(sk);
2257
	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
L
Linus Torvalds 已提交
2258
	__sk_dst_reset(sk);
2259 2260
	dst_release(sk->sk_rx_dst);
	sk->sk_rx_dst = NULL;
2261
	tcp_saved_syn_free(tp);
L
Linus Torvalds 已提交
2262

2263 2264 2265 2266
	/* Clean up fastopen related fields */
	tcp_free_fastopen_req(tp);
	inet->defer_connect = 0;

E
Eric Dumazet 已提交
2267
	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
L
Linus Torvalds 已提交
2268 2269 2270 2271

	sk->sk_error_report(sk);
	return err;
}
E
Eric Dumazet 已提交
2272
EXPORT_SYMBOL(tcp_disconnect);
L
Linus Torvalds 已提交
2273

E
Eric Dumazet 已提交
2274
static inline bool tcp_can_repair_sock(const struct sock *sk)
P
Pavel Emelyanov 已提交
2275
{
2276
	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2277
		(sk->sk_state != TCP_LISTEN);
P
Pavel Emelyanov 已提交
2278 2279
}

2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311
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;
}

2312
static int tcp_repair_options_est(struct sock *sk,
2313
		struct tcp_repair_opt __user *optbuf, unsigned int len)
2314
{
2315
	struct tcp_sock *tp = tcp_sk(sk);
2316
	struct tcp_repair_opt opt;
2317

2318 2319
	while (len >= sizeof(opt)) {
		if (copy_from_user(&opt, optbuf, sizeof(opt)))
2320 2321 2322
			return -EFAULT;

		optbuf++;
2323
		len -= sizeof(opt);
2324

2325 2326 2327
		switch (opt.opt_code) {
		case TCPOPT_MSS:
			tp->rx_opt.mss_clamp = opt.opt_val;
2328
			tcp_mtup_init(sk);
2329
			break;
2330
		case TCPOPT_WINDOW:
2331 2332 2333 2334
			{
				u16 snd_wscale = opt.opt_val & 0xFFFF;
				u16 rcv_wscale = opt.opt_val >> 16;

2335
				if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2336
					return -EFBIG;
2337

2338 2339 2340 2341
				tp->rx_opt.snd_wscale = snd_wscale;
				tp->rx_opt.rcv_wscale = rcv_wscale;
				tp->rx_opt.wscale_ok = 1;
			}
2342 2343
			break;
		case TCPOPT_SACK_PERM:
2344 2345 2346
			if (opt.opt_val != 0)
				return -EINVAL;

2347 2348 2349 2350 2351
			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
			if (sysctl_tcp_fack)
				tcp_enable_fack(tp);
			break;
		case TCPOPT_TIMESTAMP:
2352 2353 2354
			if (opt.opt_val != 0)
				return -EINVAL;

2355 2356 2357 2358 2359 2360 2361 2362
			tp->rx_opt.tstamp_ok = 1;
			break;
		}
	}

	return 0;
}

L
Linus Torvalds 已提交
2363 2364 2365
/*
 *	Socket option code for TCP.
 */
2366
static int do_tcp_setsockopt(struct sock *sk, int level,
2367
		int optname, char __user *optval, unsigned int optlen)
L
Linus Torvalds 已提交
2368 2369
{
	struct tcp_sock *tp = tcp_sk(sk);
2370
	struct inet_connection_sock *icsk = inet_csk(sk);
2371
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2372 2373 2374
	int val;
	int err = 0;

2375 2376 2377
	/* These are data/string values, all the others are ints */
	switch (optname) {
	case TCP_CONGESTION: {
2378 2379 2380 2381 2382 2383
		char name[TCP_CA_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
2384
					min_t(long, TCP_CA_NAME_MAX-1, optlen));
2385 2386 2387 2388 2389
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
2390
		err = tcp_set_congestion_control(sk, name, true);
2391 2392 2393
		release_sock(sk);
		return err;
	}
D
Dave Watson 已提交
2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411
	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;
	}
2412 2413 2414
	default:
		/* fallthru */
		break;
2415
	}
2416

L
Linus Torvalds 已提交
2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428
	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
2429 2430
		 * know which interface is going to be used
		 */
2431
		if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
L
Linus Torvalds 已提交
2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448
			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;
2449
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2450 2451 2452 2453 2454
		} else {
			tp->nonagle &= ~TCP_NAGLE_OFF;
		}
		break;

A
Andreas Petlund 已提交
2455 2456 2457 2458 2459 2460 2461
	case TCP_THIN_LINEAR_TIMEOUTS:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->thin_lto = val;
		break;

A
Andreas Petlund 已提交
2462 2463 2464 2465 2466
	case TCP_THIN_DUPACK:
		if (val < 0 || val > 1)
			err = -EINVAL;
		break;

P
Pavel Emelyanov 已提交
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 2494 2495 2496 2497 2498 2499 2500 2501 2502
	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;

2503 2504 2505 2506
	case TCP_REPAIR_OPTIONS:
		if (!tp->repair)
			err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
2507
			err = tcp_repair_options_est(sk,
2508 2509
					(struct tcp_repair_opt __user *)optval,
					optlen);
2510 2511 2512 2513
		else
			err = -EPERM;
		break;

L
Linus Torvalds 已提交
2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531
	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;
2532
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543
		}
		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))) {
2544
				u32 elapsed = keepalive_time_elapsed(tp);
L
Linus Torvalds 已提交
2545 2546 2547 2548
				if (tp->keepalive_time > elapsed)
					elapsed = tp->keepalive_time - elapsed;
				else
					elapsed = 0;
2549
				inet_csk_reset_keepalive_timer(sk, elapsed);
L
Linus Torvalds 已提交
2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568
			}
		}
		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
2569
			icsk->icsk_syn_retries = val;
L
Linus Torvalds 已提交
2570 2571
		break;

2572 2573 2574 2575 2576 2577 2578
	case TCP_SAVE_SYN:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->save_syn = val;
		break;

L
Linus Torvalds 已提交
2579 2580 2581
	case TCP_LINGER2:
		if (val < 0)
			tp->linger2 = -1;
2582
		else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
L
Linus Torvalds 已提交
2583 2584 2585 2586 2587 2588
			tp->linger2 = 0;
		else
			tp->linger2 = val * HZ;
		break;

	case TCP_DEFER_ACCEPT:
2589 2590 2591 2592
		/* Translate value in seconds to number of retransmits */
		icsk->icsk_accept_queue.rskq_defer_accept =
			secs_to_retrans(val, TCP_TIMEOUT_INIT / HZ,
					TCP_RTO_MAX / HZ);
L
Linus Torvalds 已提交
2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608
		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) {
2609
			icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2610
		} else {
2611
			icsk->icsk_ack.pingpong = 0;
L
Linus Torvalds 已提交
2612 2613
			if ((1 << sk->sk_state) &
			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2614 2615
			    inet_csk_ack_scheduled(sk)) {
				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2616
				tcp_cleanup_rbuf(sk, 1);
L
Linus Torvalds 已提交
2617
				if (!(val & 1))
2618
					icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2619 2620 2621 2622
			}
		}
		break;

2623 2624
#ifdef CONFIG_TCP_MD5SIG
	case TCP_MD5SIG:
2625
	case TCP_MD5SIG_EXT:
2626
		/* Read the IP->Key mappings from userspace */
2627
		err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
2628 2629
		break;
#endif
2630
	case TCP_USER_TIMEOUT:
2631
		/* Cap the max time in ms TCP will retry or probe the window
2632 2633
		 * before giving up and aborting (ETIMEDOUT) a connection.
		 */
2634 2635 2636 2637
		if (val < 0)
			err = -EINVAL;
		else
			icsk->icsk_user_timeout = msecs_to_jiffies(val);
2638
		break;
2639 2640 2641

	case TCP_FASTOPEN:
		if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2642 2643 2644
		    TCPF_LISTEN))) {
			tcp_fastopen_init_key_once(true);

2645
			fastopen_queue_tune(sk, val);
2646
		} else {
2647
			err = -EINVAL;
2648
		}
2649
		break;
W
Wei Wang 已提交
2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661
	case TCP_FASTOPEN_CONNECT:
		if (val > 1 || val < 0) {
			err = -EINVAL;
		} else if (sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
			if (sk->sk_state == TCP_CLOSE)
				tp->fastopen_connect = val;
			else
				err = -EINVAL;
		} else {
			err = -EOPNOTSUPP;
		}
		break;
2662 2663 2664 2665
	case TCP_TIMESTAMP:
		if (!tp->repair)
			err = -EPERM;
		else
2666
			tp->tsoffset = val - tcp_time_stamp_raw();
2667
		break;
2668 2669 2670
	case TCP_REPAIR_WINDOW:
		err = tcp_repair_set_window(tp, optval, optlen);
		break;
2671 2672 2673 2674
	case TCP_NOTSENT_LOWAT:
		tp->notsent_lowat = val;
		sk->sk_write_space(sk);
		break;
L
Linus Torvalds 已提交
2675 2676 2677
	default:
		err = -ENOPROTOOPT;
		break;
2678 2679
	}

L
Linus Torvalds 已提交
2680 2681 2682 2683
	release_sock(sk);
	return err;
}

2684
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2685
		   unsigned int optlen)
2686
{
2687
	const struct inet_connection_sock *icsk = inet_csk(sk);
2688 2689 2690 2691 2692 2693

	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
2694
EXPORT_SYMBOL(tcp_setsockopt);
2695 2696

#ifdef CONFIG_COMPAT
2697
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2698
			  char __user *optval, unsigned int optlen)
2699
{
2700 2701 2702
	if (level != SOL_TCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
2703 2704
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
2705
EXPORT_SYMBOL(compat_tcp_setsockopt);
2706 2707
#endif

2708 2709 2710 2711 2712 2713 2714 2715 2716
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)
2717
			stats[i] += tcp_jiffies32 - tp->chrono_start;
2718 2719 2720 2721 2722 2723 2724 2725 2726
		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
2727
/* Return information about state of tcp endpoint in API format. */
2728
void tcp_get_info(struct sock *sk, struct tcp_info *info)
L
Linus Torvalds 已提交
2729
{
2730
	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
2731
	const struct inet_connection_sock *icsk = inet_csk(sk);
2732
	u32 now;
2733
	u64 rate64;
2734
	bool slow;
2735
	u32 rate;
L
Linus Torvalds 已提交
2736 2737

	memset(info, 0, sizeof(*info));
2738 2739
	if (sk->sk_type != SOCK_STREAM)
		return;
L
Linus Torvalds 已提交
2740

2741 2742
	info->tcpi_state = sk_state_load(sk);

2743 2744 2745
	/* Report meaningful fields for all TCP states, including listeners */
	rate = READ_ONCE(sk->sk_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2746
	info->tcpi_pacing_rate = rate64;
2747 2748 2749

	rate = READ_ONCE(sk->sk_max_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2750
	info->tcpi_max_pacing_rate = rate64;
2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763

	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;
	}
2764 2765 2766

	slow = lock_sock_fast(sk);

2767
	info->tcpi_ca_state = icsk->icsk_ca_state;
2768
	info->tcpi_retransmits = icsk->icsk_retransmits;
2769
	info->tcpi_probes = icsk->icsk_probes_out;
2770
	info->tcpi_backoff = icsk->icsk_backoff;
L
Linus Torvalds 已提交
2771 2772 2773

	if (tp->rx_opt.tstamp_ok)
		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2774
	if (tcp_is_sack(tp))
L
Linus Torvalds 已提交
2775 2776 2777 2778 2779
		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;
2780
	}
L
Linus Torvalds 已提交
2781

E
Eric Dumazet 已提交
2782
	if (tp->ecn_flags & TCP_ECN_OK)
L
Linus Torvalds 已提交
2783
		info->tcpi_options |= TCPI_OPT_ECN;
E
Eric Dumazet 已提交
2784 2785
	if (tp->ecn_flags & TCP_ECN_SEEN)
		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Y
Yuchung Cheng 已提交
2786 2787
	if (tp->syn_data_acked)
		info->tcpi_options |= TCPI_OPT_SYN_DATA;
L
Linus Torvalds 已提交
2788

2789 2790
	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2791
	info->tcpi_snd_mss = tp->mss_cache;
2792
	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
L
Linus Torvalds 已提交
2793

2794 2795 2796
	info->tcpi_unacked = tp->packets_out;
	info->tcpi_sacked = tp->sacked_out;

L
Linus Torvalds 已提交
2797 2798 2799 2800
	info->tcpi_lost = tp->lost_out;
	info->tcpi_retrans = tp->retrans_out;
	info->tcpi_fackets = tp->fackets_out;

2801
	now = tcp_jiffies32;
L
Linus Torvalds 已提交
2802
	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2803
	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
L
Linus Torvalds 已提交
2804 2805
	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);

2806
	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
L
Linus Torvalds 已提交
2807
	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2808 2809
	info->tcpi_rtt = tp->srtt_us >> 3;
	info->tcpi_rttvar = tp->mdev_us >> 2;
L
Linus Torvalds 已提交
2810 2811 2812
	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
	info->tcpi_advmss = tp->advmss;

2813
	info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
L
Linus Torvalds 已提交
2814 2815 2816
	info->tcpi_rcv_space = tp->rcvq_space.space;

	info->tcpi_total_retrans = tp->total_retrans;
2817

2818 2819
	info->tcpi_bytes_acked = tp->bytes_acked;
	info->tcpi_bytes_received = tp->bytes_received;
2820
	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
2821
	tcp_get_info_chrono_stats(tp, info);
2822

2823 2824
	info->tcpi_segs_out = tp->segs_out;
	info->tcpi_segs_in = tp->segs_in;
2825 2826

	info->tcpi_min_rtt = tcp_min_rtt(tp);
2827 2828
	info->tcpi_data_segs_in = tp->data_segs_in;
	info->tcpi_data_segs_out = tp->data_segs_out;
Y
Yuchung Cheng 已提交
2829 2830

	info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
2831 2832
	rate64 = tcp_compute_delivery_rate(tp);
	if (rate64)
2833
		info->tcpi_delivery_rate = rate64;
2834
	unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
2835 2836 2837
}
EXPORT_SYMBOL_GPL(tcp_get_info);

2838 2839 2840 2841 2842
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;
2843 2844
	u64 rate64;
	u32 rate;
2845

2846 2847 2848
	stats = alloc_skb(7 * nla_total_size_64bit(sizeof(u64)) +
			  3 * nla_total_size(sizeof(u32)) +
			  2 * nla_total_size(sizeof(u8)), GFP_ATOMIC);
2849 2850 2851 2852 2853 2854 2855 2856 2857 2858
	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);
2859 2860 2861 2862
	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);
2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876

	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);
2877 2878 2879
	return stats;
}

2880 2881
static int do_tcp_getsockopt(struct sock *sk, int level,
		int optname, char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
2882
{
2883
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2884
	struct tcp_sock *tp = tcp_sk(sk);
2885
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897
	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:
2898
		val = tp->mss_cache;
L
Linus Torvalds 已提交
2899 2900
		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			val = tp->rx_opt.user_mss;
2901 2902
		if (tp->repair)
			val = tp->rx_opt.mss_clamp;
L
Linus Torvalds 已提交
2903 2904 2905 2906 2907 2908 2909 2910
		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
2911
		val = keepalive_time_when(tp) / HZ;
L
Linus Torvalds 已提交
2912 2913
		break;
	case TCP_KEEPINTVL:
E
Eric Dumazet 已提交
2914
		val = keepalive_intvl_when(tp) / HZ;
L
Linus Torvalds 已提交
2915 2916
		break;
	case TCP_KEEPCNT:
E
Eric Dumazet 已提交
2917
		val = keepalive_probes(tp);
L
Linus Torvalds 已提交
2918 2919
		break;
	case TCP_SYNCNT:
2920
		val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
L
Linus Torvalds 已提交
2921 2922 2923 2924
		break;
	case TCP_LINGER2:
		val = tp->linger2;
		if (val >= 0)
2925
			val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
L
Linus Torvalds 已提交
2926 2927
		break;
	case TCP_DEFER_ACCEPT:
2928 2929
		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
2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948
		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;
	}
2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968
	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
2969
	case TCP_QUICKACK:
2970
		val = !icsk->icsk_ack.pingpong;
L
Linus Torvalds 已提交
2971
		break;
2972 2973 2974 2975 2976 2977 2978

	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;
2979
		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
2980 2981
			return -EFAULT;
		return 0;
2982

D
Dave Watson 已提交
2983 2984 2985 2986
	case TCP_ULP:
		if (get_user(len, optlen))
			return -EFAULT;
		len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
2987 2988 2989 2990 2991
		if (!icsk->icsk_ulp_ops) {
			if (put_user(0, optlen))
				return -EFAULT;
			return 0;
		}
D
Dave Watson 已提交
2992 2993 2994 2995 2996 2997
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len))
			return -EFAULT;
		return 0;

2998 2999 3000
	case TCP_THIN_LINEAR_TIMEOUTS:
		val = tp->thin_lto;
		break;
Y
Yuchung Cheng 已提交
3001

3002
	case TCP_THIN_DUPACK:
Y
Yuchung Cheng 已提交
3003
		val = 0;
3004
		break;
3005

P
Pavel Emelyanov 已提交
3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016
	case TCP_REPAIR:
		val = tp->repair;
		break;

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

3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038
	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
3039 3040 3041 3042 3043 3044 3045 3046 3047
	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;

3048 3049 3050
	case TCP_USER_TIMEOUT:
		val = jiffies_to_msecs(icsk->icsk_user_timeout);
		break;
3051 3052

	case TCP_FASTOPEN:
3053
		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3054 3055
		break;

W
Wei Wang 已提交
3056 3057 3058 3059
	case TCP_FASTOPEN_CONNECT:
		val = tp->fastopen_connect;
		break;

3060
	case TCP_TIMESTAMP:
3061
		val = tcp_time_stamp_raw() + tp->tsoffset;
3062
		break;
3063 3064 3065
	case TCP_NOTSENT_LOWAT:
		val = tp->notsent_lowat;
		break;
3066 3067 3068 3069 3070 3071 3072 3073 3074
	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) {
3075 3076 3077 3078 3079 3080 3081 3082 3083
			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];
3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101
			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
3102 3103
	default:
		return -ENOPROTOOPT;
3104
	}
L
Linus Torvalds 已提交
3105 3106 3107 3108 3109 3110 3111 3112

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

3113 3114 3115 3116 3117 3118 3119 3120 3121 3122
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
3123
EXPORT_SYMBOL(tcp_getsockopt);
3124 3125

#ifdef CONFIG_COMPAT
3126 3127
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
			  char __user *optval, int __user *optlen)
3128
{
3129 3130 3131
	if (level != SOL_TCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
3132 3133
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
3134
EXPORT_SYMBOL(compat_tcp_getsockopt);
3135
#endif
L
Linus Torvalds 已提交
3136

3137
#ifdef CONFIG_TCP_MD5SIG
E
Eric Dumazet 已提交
3138
static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3139
static DEFINE_MUTEX(tcp_md5sig_mutex);
E
Eric Dumazet 已提交
3140
static bool tcp_md5sig_pool_populated = false;
3141

3142
static void __tcp_alloc_md5sig_pool(void)
3143
{
H
Herbert Xu 已提交
3144
	struct crypto_ahash *hash;
3145 3146
	int cpu;

H
Herbert Xu 已提交
3147
	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3148
	if (IS_ERR(hash))
H
Herbert Xu 已提交
3149 3150
		return;

3151
	for_each_possible_cpu(cpu) {
3152
		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
H
Herbert Xu 已提交
3153
		struct ahash_request *req;
3154

3155 3156 3157 3158 3159 3160 3161 3162 3163
		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
3164 3165 3166 3167 3168 3169 3170 3171 3172 3173
		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;
3174
	}
E
Eric Dumazet 已提交
3175 3176
	/* before setting tcp_md5sig_pool_populated, we must commit all writes
	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3177 3178
	 */
	smp_wmb();
E
Eric Dumazet 已提交
3179
	tcp_md5sig_pool_populated = true;
3180 3181
}

3182
bool tcp_alloc_md5sig_pool(void)
3183
{
E
Eric Dumazet 已提交
3184
	if (unlikely(!tcp_md5sig_pool_populated)) {
3185 3186
		mutex_lock(&tcp_md5sig_mutex);

E
Eric Dumazet 已提交
3187
		if (!tcp_md5sig_pool_populated)
3188 3189 3190
			__tcp_alloc_md5sig_pool();

		mutex_unlock(&tcp_md5sig_mutex);
3191
	}
E
Eric Dumazet 已提交
3192
	return tcp_md5sig_pool_populated;
3193 3194 3195
}
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);

E
Eric Dumazet 已提交
3196 3197 3198 3199 3200 3201 3202 3203 3204

/**
 *	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)
3205
{
E
Eric Dumazet 已提交
3206
	local_bh_disable();
3207

E
Eric Dumazet 已提交
3208 3209 3210 3211 3212
	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
3213 3214 3215 3216
	local_bh_enable();
	return NULL;
}
EXPORT_SYMBOL(tcp_get_md5sig_pool);
3217

3218
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3219
			  const struct sk_buff *skb, unsigned int header_len)
3220 3221 3222
{
	struct scatterlist sg;
	const struct tcphdr *tp = tcp_hdr(skb);
H
Herbert Xu 已提交
3223
	struct ahash_request *req = hp->md5_req;
3224 3225 3226
	unsigned int i;
	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
					   skb_headlen(skb) - header_len : 0;
3227
	const struct skb_shared_info *shi = skb_shinfo(skb);
3228
	struct sk_buff *frag_iter;
3229 3230 3231 3232

	sg_init_table(&sg, 1);

	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
H
Herbert Xu 已提交
3233 3234
	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
	if (crypto_ahash_update(req))
3235 3236 3237 3238
		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
3239 3240 3241 3242 3243
		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
3244 3245
		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
		if (crypto_ahash_update(req))
3246 3247 3248
			return 1;
	}

3249 3250 3251 3252
	skb_walk_frags(skb, frag_iter)
		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
			return 1;

3253 3254 3255 3256
	return 0;
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

3257
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3258 3259 3260 3261
{
	struct scatterlist sg;

	sg_init_one(&sg, key->key, key->keylen);
H
Herbert Xu 已提交
3262 3263
	ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
	return crypto_ahash_update(hp->md5_req);
3264 3265 3266
}
EXPORT_SYMBOL(tcp_md5_hash_key);

3267 3268
#endif

A
Andi Kleen 已提交
3269 3270
void tcp_done(struct sock *sk)
{
3271 3272
	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;

3273
	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3274
		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
A
Andi Kleen 已提交
3275 3276 3277

	tcp_set_state(sk, TCP_CLOSE);
	tcp_clear_xmit_timers(sk);
3278
	if (req)
3279
		reqsk_fastopen_remove(sk, req, false);
A
Andi Kleen 已提交
3280 3281 3282 3283 3284 3285 3286 3287 3288 3289

	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);

3290 3291 3292
int tcp_abort(struct sock *sk, int err)
{
	if (!sk_fullsock(sk)) {
3293 3294 3295 3296 3297 3298 3299 3300 3301
		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;
		}
3302 3303 3304 3305 3306 3307
		return -EOPNOTSUPP;
	}

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

3308 3309 3310 3311 3312
	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);
		inet_csk_listen_stop(sk);
	}

3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333
	/* Don't race with BH socket closes such as inet_csk_listen_stop. */
	local_bh_disable();
	bh_lock_sock(sk);

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

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

3334
extern struct tcp_congestion_ops tcp_reno;
L
Linus Torvalds 已提交
3335 3336 3337 3338

static __initdata unsigned long thash_entries;
static int __init set_thash_entries(char *str)
{
3339 3340
	ssize_t ret;

L
Linus Torvalds 已提交
3341 3342
	if (!str)
		return 0;
3343 3344 3345 3346 3347

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

L
Linus Torvalds 已提交
3348 3349 3350 3351
	return 1;
}
__setup("thash_entries=", set_thash_entries);

F
Fabian Frederick 已提交
3352
static void __init tcp_init_mem(void)
3353
{
E
Eric Dumazet 已提交
3354 3355
	unsigned long limit = nr_free_buffer_pages() / 16;

3356
	limit = max(limit, 128UL);
E
Eric Dumazet 已提交
3357 3358 3359
	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 % */
3360 3361
}

L
Linus Torvalds 已提交
3362 3363
void __init tcp_init(void)
{
3364
	int max_rshare, max_wshare, cnt;
3365
	unsigned long limit;
3366
	unsigned int i;
L
Linus Torvalds 已提交
3367

3368 3369
	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
L
Linus Torvalds 已提交
3370

3371 3372
	percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
	percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3373
	inet_hashinfo_init(&tcp_hashinfo);
3374 3375 3376
	tcp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("tcp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
3377
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
3378 3379 3380 3381 3382 3383

	/* Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
3384
	tcp_hashinfo.ehash =
L
Linus Torvalds 已提交
3385
		alloc_large_system_hash("TCP established",
3386
					sizeof(struct inet_ehash_bucket),
L
Linus Torvalds 已提交
3387
					thash_entries,
E
Eric Dumazet 已提交
3388
					17, /* one slot per 128 KB of memory */
3389
					0,
L
Linus Torvalds 已提交
3390
					NULL,
3391
					&tcp_hashinfo.ehash_mask,
3392
					0,
3393
					thash_entries ? 0 : 512 * 1024);
E
Eric Dumazet 已提交
3394
	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3395
		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
E
Eric Dumazet 已提交
3396

3397 3398
	if (inet_ehash_locks_alloc(&tcp_hashinfo))
		panic("TCP: failed to alloc ehash_locks");
3399
	tcp_hashinfo.bhash =
L
Linus Torvalds 已提交
3400
		alloc_large_system_hash("TCP bind",
3401
					sizeof(struct inet_bind_hashbucket),
3402
					tcp_hashinfo.ehash_mask + 1,
E
Eric Dumazet 已提交
3403
					17, /* one slot per 128 KB of memory */
3404
					0,
3405
					&tcp_hashinfo.bhash_size,
L
Linus Torvalds 已提交
3406
					NULL,
3407
					0,
L
Linus Torvalds 已提交
3408
					64 * 1024);
3409
	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3410 3411 3412
	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
3413 3414
	}

E
Eric Dumazet 已提交
3415 3416 3417

	cnt = tcp_hashinfo.ehash_mask + 1;
	sysctl_tcp_max_orphans = cnt / 2;
L
Linus Torvalds 已提交
3418

3419
	tcp_init_mem();
3420
	/* Set per-socket limits to no more than 1/128 the pressure threshold */
E
Eric Dumazet 已提交
3421
	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3422 3423
	max_wshare = min(4UL*1024*1024, limit);
	max_rshare = min(6UL*1024*1024, limit);
3424

3425
	sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3426
	sysctl_tcp_wmem[1] = 16*1024;
3427
	sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
3428

3429
	sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3430
	sysctl_tcp_rmem[1] = 87380;
3431
	sysctl_tcp_rmem[2] = max(87380, max_rshare);
L
Linus Torvalds 已提交
3432

3433
	pr_info("Hash tables configured (established %u bind %u)\n",
J
Joe Perches 已提交
3434
		tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3435

3436
	tcp_v4_init();
3437
	tcp_metrics_init();
3438
	BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
E
Eric Dumazet 已提交
3439
	tcp_tasklet_init();
L
Linus Torvalds 已提交
3440
}