tcp.c 91.1 KB
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/*
 * INET		An implementation of the TCP/IP protocol suite for the LINUX
 *		operating system.  INET is implemented using the  BSD Socket
 *		interface as the means of communication with the user level.
 *
 *		Implementation of the Transmission Control Protocol(TCP).
 *
8
 * Authors:	Ross Biro
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 *		Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *		Mark Evans, <evansmp@uhura.aston.ac.uk>
 *		Corey Minyard <wf-rch!minyard@relay.EU.net>
 *		Florian La Roche, <flla@stud.uni-sb.de>
 *		Charles Hedrick, <hedrick@klinzhai.rutgers.edu>
 *		Linus Torvalds, <torvalds@cs.helsinki.fi>
 *		Alan Cox, <gw4pts@gw4pts.ampr.org>
 *		Matthew Dillon, <dillon@apollo.west.oic.com>
 *		Arnt Gulbrandsen, <agulbra@nvg.unit.no>
 *		Jorge Cwik, <jorge@laser.satlink.net>
 *
 * Fixes:
 *		Alan Cox	:	Numerous verify_area() calls
 *		Alan Cox	:	Set the ACK bit on a reset
 *		Alan Cox	:	Stopped it crashing if it closed while
 *					sk->inuse=1 and was trying to connect
 *					(tcp_err()).
 *		Alan Cox	:	All icmp error handling was broken
 *					pointers passed where wrong and the
 *					socket was looked up backwards. Nobody
 *					tested any icmp error code obviously.
 *		Alan Cox	:	tcp_err() now handled properly. It
 *					wakes people on errors. poll
 *					behaves and the icmp error race
 *					has gone by moving it into sock.c
 *		Alan Cox	:	tcp_send_reset() fixed to work for
 *					everything not just packets for
 *					unknown sockets.
 *		Alan Cox	:	tcp option processing.
 *		Alan Cox	:	Reset tweaked (still not 100%) [Had
 *					syn rule wrong]
 *		Herp Rosmanith  :	More reset fixes
 *		Alan Cox	:	No longer acks invalid rst frames.
 *					Acking any kind of RST is right out.
 *		Alan Cox	:	Sets an ignore me flag on an rst
 *					receive otherwise odd bits of prattle
 *					escape still
 *		Alan Cox	:	Fixed another acking RST frame bug.
 *					Should stop LAN workplace lockups.
 *		Alan Cox	: 	Some tidyups using the new skb list
 *					facilities
 *		Alan Cox	:	sk->keepopen now seems to work
 *		Alan Cox	:	Pulls options out correctly on accepts
 *		Alan Cox	:	Fixed assorted sk->rqueue->next errors
 *		Alan Cox	:	PSH doesn't end a TCP read. Switched a
 *					bit to skb ops.
 *		Alan Cox	:	Tidied tcp_data to avoid a potential
 *					nasty.
 *		Alan Cox	:	Added some better commenting, as the
 *					tcp is hard to follow
 *		Alan Cox	:	Removed incorrect check for 20 * psh
 *	Michael O'Reilly	:	ack < copied bug fix.
 *	Johannes Stille		:	Misc tcp fixes (not all in yet).
 *		Alan Cox	:	FIN with no memory -> CRASH
 *		Alan Cox	:	Added socket option proto entries.
 *					Also added awareness of them to accept.
 *		Alan Cox	:	Added TCP options (SOL_TCP)
 *		Alan Cox	:	Switched wakeup calls to callbacks,
 *					so the kernel can layer network
 *					sockets.
 *		Alan Cox	:	Use ip_tos/ip_ttl settings.
 *		Alan Cox	:	Handle FIN (more) properly (we hope).
 *		Alan Cox	:	RST frames sent on unsynchronised
 *					state ack error.
 *		Alan Cox	:	Put in missing check for SYN bit.
 *		Alan Cox	:	Added tcp_select_window() aka NET2E
 *					window non shrink trick.
 *		Alan Cox	:	Added a couple of small NET2E timer
 *					fixes
 *		Charles Hedrick :	TCP fixes
 *		Toomas Tamm	:	TCP window fixes
 *		Alan Cox	:	Small URG fix to rlogin ^C ack fight
 *		Charles Hedrick	:	Rewrote most of it to actually work
 *		Linus		:	Rewrote tcp_read() and URG handling
 *					completely
 *		Gerhard Koerting:	Fixed some missing timer handling
 *		Matthew Dillon  :	Reworked TCP machine states as per RFC
 *		Gerhard Koerting:	PC/TCP workarounds
 *		Adam Caldwell	:	Assorted timer/timing errors
 *		Matthew Dillon	:	Fixed another RST bug
 *		Alan Cox	:	Move to kernel side addressing changes.
 *		Alan Cox	:	Beginning work on TCP fastpathing
 *					(not yet usable)
 *		Arnt Gulbrandsen:	Turbocharged tcp_check() routine.
 *		Alan Cox	:	TCP fast path debugging
 *		Alan Cox	:	Window clamping
 *		Michael Riepe	:	Bug in tcp_check()
 *		Matt Dillon	:	More TCP improvements and RST bug fixes
 *		Matt Dillon	:	Yet more small nasties remove from the
 *					TCP code (Be very nice to this man if
 *					tcp finally works 100%) 8)
 *		Alan Cox	:	BSD accept semantics.
 *		Alan Cox	:	Reset on closedown bug.
 *	Peter De Schrijver	:	ENOTCONN check missing in tcp_sendto().
 *		Michael Pall	:	Handle poll() after URG properly in
 *					all cases.
 *		Michael Pall	:	Undo the last fix in tcp_read_urg()
 *					(multi URG PUSH broke rlogin).
 *		Michael Pall	:	Fix the multi URG PUSH problem in
 *					tcp_readable(), poll() after URG
 *					works now.
 *		Michael Pall	:	recv(...,MSG_OOB) never blocks in the
 *					BSD api.
 *		Alan Cox	:	Changed the semantics of sk->socket to
 *					fix a race and a signal problem with
 *					accept() and async I/O.
 *		Alan Cox	:	Relaxed the rules on tcp_sendto().
 *		Yury Shevchuk	:	Really fixed accept() blocking problem.
 *		Craig I. Hagan  :	Allow for BSD compatible TIME_WAIT for
 *					clients/servers which listen in on
 *					fixed ports.
 *		Alan Cox	:	Cleaned the above up and shrank it to
 *					a sensible code size.
 *		Alan Cox	:	Self connect lockup fix.
 *		Alan Cox	:	No connect to multicast.
 *		Ross Biro	:	Close unaccepted children on master
 *					socket close.
 *		Alan Cox	:	Reset tracing code.
 *		Alan Cox	:	Spurious resets on shutdown.
 *		Alan Cox	:	Giant 15 minute/60 second timer error
 *		Alan Cox	:	Small whoops in polling before an
 *					accept.
 *		Alan Cox	:	Kept the state trace facility since
 *					it's handy for debugging.
 *		Alan Cox	:	More reset handler fixes.
 *		Alan Cox	:	Started rewriting the code based on
 *					the RFC's for other useful protocol
 *					references see: Comer, KA9Q NOS, and
 *					for a reference on the difference
 *					between specifications and how BSD
 *					works see the 4.4lite source.
 *		A.N.Kuznetsov	:	Don't time wait on completion of tidy
 *					close.
 *		Linus Torvalds	:	Fin/Shutdown & copied_seq changes.
 *		Linus Torvalds	:	Fixed BSD port reuse to work first syn
 *		Alan Cox	:	Reimplemented timers as per the RFC
 *					and using multiple timers for sanity.
 *		Alan Cox	:	Small bug fixes, and a lot of new
 *					comments.
 *		Alan Cox	:	Fixed dual reader crash by locking
 *					the buffers (much like datagram.c)
 *		Alan Cox	:	Fixed stuck sockets in probe. A probe
 *					now gets fed up of retrying without
 *					(even a no space) answer.
 *		Alan Cox	:	Extracted closing code better
 *		Alan Cox	:	Fixed the closing state machine to
 *					resemble the RFC.
 *		Alan Cox	:	More 'per spec' fixes.
 *		Jorge Cwik	:	Even faster checksumming.
 *		Alan Cox	:	tcp_data() doesn't ack illegal PSH
 *					only frames. At least one pc tcp stack
 *					generates them.
 *		Alan Cox	:	Cache last socket.
 *		Alan Cox	:	Per route irtt.
 *		Matt Day	:	poll()->select() match BSD precisely on error
 *		Alan Cox	:	New buffers
 *		Marc Tamsky	:	Various sk->prot->retransmits and
 *					sk->retransmits misupdating fixed.
 *					Fixed tcp_write_timeout: stuck close,
 *					and TCP syn retries gets used now.
 *		Mark Yarvis	:	In tcp_read_wakeup(), don't send an
 *					ack if state is TCP_CLOSED.
 *		Alan Cox	:	Look up device on a retransmit - routes may
 *					change. Doesn't yet cope with MSS shrink right
 *					but it's a start!
 *		Marc Tamsky	:	Closing in closing fixes.
 *		Mike Shaver	:	RFC1122 verifications.
 *		Alan Cox	:	rcv_saddr errors.
 *		Alan Cox	:	Block double connect().
 *		Alan Cox	:	Small hooks for enSKIP.
 *		Alexey Kuznetsov:	Path MTU discovery.
 *		Alan Cox	:	Support soft errors.
 *		Alan Cox	:	Fix MTU discovery pathological case
 *					when the remote claims no mtu!
 *		Marc Tamsky	:	TCP_CLOSE fix.
 *		Colin (G3TNE)	:	Send a reset on syn ack replies in
 *					window but wrong (fixes NT lpd problems)
 *		Pedro Roque	:	Better TCP window handling, delayed ack.
 *		Joerg Reuter	:	No modification of locked buffers in
 *					tcp_do_retransmit()
 *		Eric Schenk	:	Changed receiver side silly window
 *					avoidance algorithm to BSD style
 *					algorithm. This doubles throughput
 *					against machines running Solaris,
 *					and seems to result in general
 *					improvement.
 *	Stefan Magdalinski	:	adjusted tcp_readable() to fix FIONREAD
 *	Willy Konynenberg	:	Transparent proxying support.
 *	Mike McLagan		:	Routing by source
 *		Keith Owens	:	Do proper merging with partial SKB's in
 *					tcp_do_sendmsg to avoid burstiness.
 *		Eric Schenk	:	Fix fast close down bug with
 *					shutdown() followed by close().
 *		Andi Kleen 	:	Make poll agree with SIGIO
 *	Salvatore Sanfilippo	:	Support SO_LINGER with linger == 1 and
 *					lingertime == 0 (RFC 793 ABORT Call)
 *	Hirokazu Takahashi	:	Use copy_from_user() instead of
 *					csum_and_copy_from_user() if possible.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or(at your option) any later version.
 *
 * Description of States:
 *
 *	TCP_SYN_SENT		sent a connection request, waiting for ack
 *
 *	TCP_SYN_RECV		received a connection request, sent ack,
 *				waiting for final ack in three-way handshake.
 *
 *	TCP_ESTABLISHED		connection established
 *
 *	TCP_FIN_WAIT1		our side has shutdown, waiting to complete
 *				transmission of remaining buffered data
 *
 *	TCP_FIN_WAIT2		all buffered data sent, waiting for remote
 *				to shutdown
 *
 *	TCP_CLOSING		both sides have shutdown but we still have
 *				data we have to finish sending
 *
 *	TCP_TIME_WAIT		timeout to catch resent junk before entering
 *				closed, can only be entered from FIN_WAIT2
 *				or CLOSING.  Required because the other end
 *				may not have gotten our last ACK causing it
 *				to retransmit the data packet (which we ignore)
 *
 *	TCP_CLOSE_WAIT		remote side has shutdown and is waiting for
 *				us to finish writing our data and to shutdown
 *				(we have to close() to move on to LAST_ACK)
 *
 *	TCP_LAST_ACK		out side has shutdown after remote has
 *				shutdown.  There may still be data in our
 *				buffer that we have to finish sending
 *
 *	TCP_CLOSE		socket is finished
 */

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#define pr_fmt(fmt) "TCP: " fmt

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#include <crypto/hash.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
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#include <linux/inet_diag.h>
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#include <linux/init.h>
#include <linux/fs.h>
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#include <linux/skbuff.h>
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#include <linux/scatterlist.h>
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#include <linux/splice.h>
#include <linux/net.h>
#include <linux/socket.h>
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#include <linux/random.h>
#include <linux/bootmem.h>
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#include <linux/highmem.h>
#include <linux/swap.h>
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#include <linux/cache.h>
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#include <linux/err.h>
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#include <linux/time.h>
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#include <linux/slab.h>
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#include <linux/errqueue.h>
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#include <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)) {
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		int target = sock_rcvlowat(sk, 0, INT_MAX);

		if (tp->urg_seq == tp->copied_seq &&
		    !sock_flag(sk, SOCK_URGINLINE) &&
		    tp->urg_data)
542
			target++;
543 544

		if (tp->rcv_nxt - tp->copied_seq >= target)
L
Linus Torvalds 已提交
545 546 547
			mask |= POLLIN | POLLRDNORM;

		if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
548
			if (sk_stream_is_writeable(sk)) {
L
Linus Torvalds 已提交
549 550
				mask |= POLLOUT | POLLWRNORM;
			} else {  /* send SIGIO later */
551
				sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
552 553 554 555
				set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);

				/* Race breaker. If space is freed after
				 * wspace test but before the flags are set,
556 557
				 * IO signal will be lost. Memory barrier
				 * pairs with the input side.
L
Linus Torvalds 已提交
558
				 */
559
				smp_mb__after_atomic();
560
				if (sk_stream_is_writeable(sk))
L
Linus Torvalds 已提交
561 562
					mask |= POLLOUT | POLLWRNORM;
			}
563 564
		} else
			mask |= POLLOUT | POLLWRNORM;
L
Linus Torvalds 已提交
565 566 567

		if (tp->urg_data & TCP_URG_VALID)
			mask |= POLLPRI;
568
	} else if (state == TCP_SYN_SENT && inet_sk(sk)->defer_connect) {
W
Wei Wang 已提交
569 570 571 572 573
		/* 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
574
	}
T
Tom Marshall 已提交
575 576
	/* This barrier is coupled with smp_wmb() in tcp_reset() */
	smp_rmb();
577
	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
T
Tom Marshall 已提交
578 579
		mask |= POLLERR;

L
Linus Torvalds 已提交
580 581
	return mask;
}
E
Eric Dumazet 已提交
582
EXPORT_SYMBOL(tcp_poll);
L
Linus Torvalds 已提交
583 584 585 586 587

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
588
	bool slow;
L
Linus Torvalds 已提交
589 590 591 592 593 594

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

E
Eric Dumazet 已提交
595
		slow = lock_sock_fast(sk);
596
		answ = tcp_inq(sk);
E
Eric Dumazet 已提交
597
		unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
598 599 600 601 602 603 604 605 606 607 608 609 610
		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;
611 612 613 614 615 616 617 618 619
	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
620 621
	default:
		return -ENOIOCTLCMD;
622
	}
L
Linus Torvalds 已提交
623 624 625

	return put_user(answ, (int __user *)arg);
}
E
Eric Dumazet 已提交
626
EXPORT_SYMBOL(tcp_ioctl);
L
Linus Torvalds 已提交
627 628 629

static inline void tcp_mark_push(struct tcp_sock *tp, struct sk_buff *skb)
{
E
Eric Dumazet 已提交
630
	TCP_SKB_CB(skb)->tcp_flags |= TCPHDR_PSH;
L
Linus Torvalds 已提交
631 632 633
	tp->pushed_seq = tp->write_seq;
}

E
Eric Dumazet 已提交
634
static inline bool forced_push(const struct tcp_sock *tp)
L
Linus Torvalds 已提交
635 636 637 638
{
	return after(tp->write_seq, tp->pushed_seq + (tp->max_window >> 1));
}

639
static void skb_entail(struct sock *sk, struct sk_buff *skb)
L
Linus Torvalds 已提交
640
{
641
	struct tcp_sock *tp = tcp_sk(sk);
642 643 644 645
	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
646
	tcb->tcp_flags = TCPHDR_ACK;
647
	tcb->sacked  = 0;
648
	__skb_header_release(skb);
649
	tcp_add_write_queue_tail(sk, skb);
650 651
	sk->sk_wmem_queued += skb->truesize;
	sk_mem_charge(sk, skb->truesize);
652
	if (tp->nonagle & TCP_NAGLE_PUSH)
653
		tp->nonagle &= ~TCP_NAGLE_PUSH;
654 655

	tcp_slow_start_after_idle_check(sk);
L
Linus Torvalds 已提交
656 657
}

658
static inline void tcp_mark_urg(struct tcp_sock *tp, int flags)
L
Linus Torvalds 已提交
659
{
I
Ilpo Järvinen 已提交
660
	if (flags & MSG_OOB)
L
Linus Torvalds 已提交
661 662 663
		tp->snd_up = tp->write_seq;
}

E
Eric Dumazet 已提交
664
/* If a not yet filled skb is pushed, do not send it if
665
 * we have data packets in Qdisc or NIC queues :
E
Eric Dumazet 已提交
666 667 668 669
 * 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
670 671 672
 * 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
673 674 675
 */
static bool tcp_should_autocork(struct sock *sk, struct sk_buff *skb,
				int size_goal)
L
Linus Torvalds 已提交
676
{
E
Eric Dumazet 已提交
677 678
	return skb->len < size_goal &&
	       sysctl_tcp_autocorking &&
679
	       skb != tcp_write_queue_head(sk) &&
680
	       refcount_read(&sk->sk_wmem_alloc) > skb->truesize;
E
Eric Dumazet 已提交
681 682 683 684 685 686 687
}

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;
688

E
Eric Dumazet 已提交
689 690
	if (!tcp_send_head(sk))
		return;
691

E
Eric Dumazet 已提交
692 693 694 695 696 697 698 699 700
	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 */
701
		if (!test_bit(TSQ_THROTTLED, &sk->sk_tsq_flags)) {
E
Eric Dumazet 已提交
702
			NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAUTOCORKING);
703
			set_bit(TSQ_THROTTLED, &sk->sk_tsq_flags);
E
Eric Dumazet 已提交
704
		}
705 706 707
		/* It is possible TX completion already happened
		 * before we set TSQ_THROTTLED.
		 */
708
		if (refcount_read(&sk->sk_wmem_alloc) > skb->truesize)
709
			return;
L
Linus Torvalds 已提交
710
	}
E
Eric Dumazet 已提交
711 712 713 714 715

	if (flags & MSG_MORE)
		nonagle = TCP_NAGLE_CORK;

	__tcp_push_pending_frames(sk, mss_now, nonagle);
L
Linus Torvalds 已提交
716 717
}

718 719
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
720 721
{
	struct tcp_splice_state *tss = rd_desc->arg.data;
722
	int ret;
J
Jens Axboe 已提交
723

724
	ret = skb_splice_bits(skb, skb->sk, offset, tss->pipe,
A
Al Viro 已提交
725
			      min(rd_desc->count, len), tss->flags);
726 727 728
	if (ret > 0)
		rd_desc->count -= ret;
	return ret;
J
Jens Axboe 已提交
729 730 731 732 733 734 735
}

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,
736
		.count	  = tss->len,
J
Jens Axboe 已提交
737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767
	};

	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;

768
	sock_rps_record_flow(sk);
J
Jens Axboe 已提交
769 770 771 772 773 774 775 776 777 778
	/*
	 * We can't seek on a socket input
	 */
	if (unlikely(*ppos))
		return -ESPIPE;

	ret = spliced = 0;

	lock_sock(sk);

779
	timeo = sock_rcvtimeo(sk, sock->file->f_flags & O_NONBLOCK);
J
Jens Axboe 已提交
780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807
	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;
			}
808 809 810 811 812 813
			/* 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;
814
			sk_wait_data(sk, &timeo, NULL);
J
Jens Axboe 已提交
815 816 817 818 819 820 821 822 823
			if (signal_pending(current)) {
				ret = sock_intr_errno(timeo);
				break;
			}
			continue;
		}
		tss.len -= ret;
		spliced += ret;

824 825
		if (!timeo)
			break;
J
Jens Axboe 已提交
826 827 828 829
		release_sock(sk);
		lock_sock(sk);

		if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
830
		    (sk->sk_shutdown & RCV_SHUTDOWN) ||
J
Jens Axboe 已提交
831 832 833 834 835 836 837 838 839 840 841
		    signal_pending(current))
			break;
	}

	release_sock(sk);

	if (spliced)
		return spliced;

	return ret;
}
E
Eric Dumazet 已提交
842
EXPORT_SYMBOL(tcp_splice_read);
J
Jens Axboe 已提交
843

844 845
struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp,
				    bool force_schedule)
846 847 848 849 850 851
{
	struct sk_buff *skb;

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

852 853 854
	if (unlikely(tcp_under_memory_pressure(sk)))
		sk_mem_reclaim_partial(sk);

855
	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
856
	if (likely(skb)) {
857
		bool mem_scheduled;
858

859 860
		if (force_schedule) {
			mem_scheduled = true;
861 862
			sk_forced_mem_schedule(sk, skb->truesize);
		} else {
863
			mem_scheduled = sk_wmem_schedule(sk, skb->truesize);
864
		}
865
		if (likely(mem_scheduled)) {
866
			skb_reserve(skb, sk->sk_prot->max_header);
867 868 869 870
			/*
			 * Make sure that we have exactly size bytes
			 * available to the caller, no more, no less.
			 */
E
Eric Dumazet 已提交
871
			skb->reserved_tailroom = skb->end - skb->tail - size;
872 873 874 875
			return skb;
		}
		__kfree_skb(skb);
	} else {
876
		sk->sk_prot->enter_memory_pressure(sk);
877 878 879 880 881
		sk_stream_moderate_sndbuf(sk);
	}
	return NULL;
}

I
Ilpo Järvinen 已提交
882 883 884 885
static unsigned int tcp_xmit_size_goal(struct sock *sk, u32 mss_now,
				       int large_allowed)
{
	struct tcp_sock *tp = tcp_sk(sk);
886
	u32 new_size_goal, size_goal;
E
Eric Dumazet 已提交
887 888 889 890

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

891 892
	/* 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
893 894 895 896 897 898 899 900 901
	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
902 903
	}

E
Eric Dumazet 已提交
904
	return max(size_goal, mss_now);
I
Ilpo Järvinen 已提交
905 906 907 908 909 910 911 912 913 914 915 916
}

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;
}

917 918
ssize_t do_tcp_sendpages(struct sock *sk, struct page *page, int offset,
			 size_t size, int flags)
L
Linus Torvalds 已提交
919 920
{
	struct tcp_sock *tp = tcp_sk(sk);
921
	int mss_now, size_goal;
L
Linus Torvalds 已提交
922 923 924 925
	int err;
	ssize_t copied;
	long timeo = sock_sndtimeo(sk, flags & MSG_DONTWAIT);

926 927 928 929 930 931
	/* 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)) {
932 933
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
934
			goto out_err;
935
	}
L
Linus Torvalds 已提交
936

937
	sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
L
Linus Torvalds 已提交
938

I
Ilpo Järvinen 已提交
939
	mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
940 941 942 943
	copied = 0;

	err = -EPIPE;
	if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
944
		goto out_err;
L
Linus Torvalds 已提交
945

946
	while (size > 0) {
947
		struct sk_buff *skb = tcp_write_queue_tail(sk);
948 949
		int copy, i;
		bool can_coalesce;
L
Linus Torvalds 已提交
950

951 952
		if (!tcp_send_head(sk) || (copy = size_goal - skb->len) <= 0 ||
		    !tcp_skb_can_collapse_to(skb)) {
L
Linus Torvalds 已提交
953 954 955 956
new_segment:
			if (!sk_stream_memory_free(sk))
				goto wait_for_sndbuf;

957 958
			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation,
						  skb_queue_empty(&sk->sk_write_queue));
L
Linus Torvalds 已提交
959 960 961
			if (!skb)
				goto wait_for_memory;

962
			skb_entail(sk, skb);
963
			copy = size_goal;
L
Linus Torvalds 已提交
964 965 966 967 968 969 970
		}

		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
971
		if (!can_coalesce && i >= sysctl_max_skb_frags) {
L
Linus Torvalds 已提交
972 973 974
			tcp_mark_push(tp, skb);
			goto new_segment;
		}
975
		if (!sk_wmem_schedule(sk, copy))
L
Linus Torvalds 已提交
976
			goto wait_for_memory;
977

L
Linus Torvalds 已提交
978
		if (can_coalesce) {
E
Eric Dumazet 已提交
979
			skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
L
Linus Torvalds 已提交
980 981 982 983
		} else {
			get_page(page);
			skb_fill_page_desc(skb, i, page, offset, copy);
		}
984
		skb_shinfo(skb)->tx_flags |= SKBTX_SHARED_FRAG;
985

L
Linus Torvalds 已提交
986 987 988 989
		skb->len += copy;
		skb->data_len += copy;
		skb->truesize += copy;
		sk->sk_wmem_queued += copy;
990
		sk_mem_charge(sk, copy);
991
		skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
992 993
		tp->write_seq += copy;
		TCP_SKB_CB(skb)->end_seq += copy;
994
		tcp_skb_pcount_set(skb, 0);
L
Linus Torvalds 已提交
995 996

		if (!copied)
E
Eric Dumazet 已提交
997
			TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH;
L
Linus Torvalds 已提交
998 999

		copied += copy;
1000
		offset += copy;
1001
		size -= copy;
1002
		if (!size)
L
Linus Torvalds 已提交
1003 1004
			goto out;

1005
		if (skb->len < size_goal || (flags & MSG_OOB))
L
Linus Torvalds 已提交
1006 1007 1008 1009
			continue;

		if (forced_push(tp)) {
			tcp_mark_push(tp, skb);
1010
			__tcp_push_pending_frames(sk, mss_now, TCP_NAGLE_PUSH);
1011
		} else if (skb == tcp_send_head(sk))
L
Linus Torvalds 已提交
1012 1013 1014 1015 1016 1017
			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
1018 1019
		tcp_push(sk, flags & ~MSG_MORE, mss_now,
			 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1020

1021 1022
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
L
Linus Torvalds 已提交
1023 1024
			goto do_error;

I
Ilpo Järvinen 已提交
1025
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1026 1027 1028
	}

out:
1029 1030 1031 1032 1033
	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
1034 1035 1036 1037 1038 1039
	return copied;

do_error:
	if (copied)
		goto out;
out_err:
1040
	/* make sure we wake any epoll edge trigger waiter */
1041 1042
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1043
		sk->sk_write_space(sk);
1044 1045
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1046 1047
	return sk_stream_error(sk, flags, err);
}
1048
EXPORT_SYMBOL_GPL(do_tcp_sendpages);
L
Linus Torvalds 已提交
1049

1050 1051
int tcp_sendpage_locked(struct sock *sk, struct page *page, int offset,
			size_t size, int flags)
L
Linus Torvalds 已提交
1052 1053
{
	if (!(sk->sk_route_caps & NETIF_F_SG) ||
1054
	    !sk_check_csum_caps(sk))
1055
		return sock_no_sendpage_locked(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1056

1057 1058
	tcp_rate_check_app_limited(sk);  /* is sending application-limited? */

1059 1060
	return do_tcp_sendpages(sk, page, offset, size, flags);
}
1061
EXPORT_SYMBOL_GPL(tcp_sendpage_locked);
1062 1063 1064 1065 1066 1067 1068 1069

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

	lock_sock(sk);
	ret = tcp_sendpage_locked(sk, page, offset, size, flags);
L
Linus Torvalds 已提交
1070
	release_sock(sk);
1071 1072

	return ret;
L
Linus Torvalds 已提交
1073
}
E
Eric Dumazet 已提交
1074
EXPORT_SYMBOL(tcp_sendpage);
L
Linus Torvalds 已提交
1075

1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093
/* 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
1094
{
1095
	const struct tcp_sock *tp = tcp_sk(sk);
1096
	int tmp = tp->mss_cache;
L
Linus Torvalds 已提交
1097

K
Krishna Kumar 已提交
1098
	if (sg) {
1099
		if (sk_can_gso(sk)) {
1100
			tmp = linear_payload_sz(first_skb);
1101
		} else {
1102 1103 1104 1105 1106 1107 1108
			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
1109 1110 1111 1112

	return tmp;
}

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

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

1129
	if (!(sock_net(sk)->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) ||
1130 1131
	    (uaddr && msg->msg_namelen >= sizeof(uaddr->sa_family) &&
	     uaddr->sa_family == AF_UNSPEC))
1132
		return -EOPNOTSUPP;
1133
	if (tp->fastopen_req)
1134 1135 1136 1137
		return -EALREADY; /* Another Fast Open is in progress */

	tp->fastopen_req = kzalloc(sizeof(struct tcp_fastopen_request),
				   sk->sk_allocation);
1138
	if (unlikely(!tp->fastopen_req))
1139 1140
		return -ENOBUFS;
	tp->fastopen_req->data = msg;
1141
	tp->fastopen_req->size = size;
1142

W
Wei Wang 已提交
1143 1144 1145 1146 1147 1148 1149 1150 1151
	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;
		}
	}
1152
	flags = (msg->msg_flags & MSG_DONTWAIT) ? O_NONBLOCK : 0;
1153
	err = __inet_stream_connect(sk->sk_socket, uaddr,
1154
				    msg->msg_namelen, flags, 1);
1155 1156 1157 1158 1159 1160 1161 1162
	/* 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;
	}
1163 1164 1165
	return err;
}

1166
int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
L
Linus Torvalds 已提交
1167 1168
{
	struct tcp_sock *tp = tcp_sk(sk);
W
Willem de Bruijn 已提交
1169
	struct ubuf_info *uarg = NULL;
L
Linus Torvalds 已提交
1170
	struct sk_buff *skb;
1171
	struct sockcm_cookie sockc;
1172 1173
	int flags, err, copied = 0;
	int mss_now = 0, size_goal, copied_syn = 0;
1174
	bool process_backlog = false;
1175
	bool sg;
L
Linus Torvalds 已提交
1176 1177 1178
	long timeo;

	flags = msg->msg_flags;
W
Willem de Bruijn 已提交
1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196

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

		skb = tcp_send_head(sk) ? tcp_write_queue_tail(sk) : NULL;
		uarg = sock_zerocopy_realloc(sk, size, skb_zcopy(skb));
		if (!uarg) {
			err = -ENOBUFS;
			goto out_err;
		}

		if (!(sk_check_csum_caps(sk) && sk->sk_route_caps & NETIF_F_SG))
			uarg->zerocopy = 0;
	}

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

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

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

1209 1210 1211 1212 1213 1214
	/* Wait for a connection to finish. One exception is TCP Fast Open
	 * (passive side) where data is allowed to be sent before a connection
	 * is fully established.
	 */
	if (((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) &&
	    !tcp_passive_fastopen(sk)) {
1215 1216
		err = sk_stream_wait_connect(sk, &timeo);
		if (err != 0)
1217
			goto do_error;
1218
	}
L
Linus Torvalds 已提交
1219

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

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

		/* 'common' sending to sendq */
	}

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

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

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

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

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

1255
	sg = !!(sk->sk_route_caps & NETIF_F_SG);
K
Krishna Kumar 已提交
1256

A
Al Viro 已提交
1257
	while (msg_data_left(msg)) {
1258 1259
		int copy = 0;
		int max = size_goal;
L
Linus Torvalds 已提交
1260

1261 1262 1263 1264 1265
		skb = tcp_write_queue_tail(sk);
		if (tcp_send_head(sk)) {
			if (skb->ip_summed == CHECKSUM_NONE)
				max = mss_now;
			copy = max - skb->len;
1266
		}
L
Linus Torvalds 已提交
1267

1268
		if (copy <= 0 || !tcp_skb_can_collapse_to(skb)) {
1269 1270
			bool first_skb;

L
Linus Torvalds 已提交
1271
new_segment:
1272 1273 1274 1275 1276
			/* 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
1277

1278 1279
			if (process_backlog && sk_flush_backlog(sk)) {
				process_backlog = false;
1280
				goto restart;
1281
			}
1282
			first_skb = skb_queue_empty(&sk->sk_write_queue);
1283
			skb = sk_stream_alloc_skb(sk,
1284
						  select_size(sk, sg, first_skb),
1285
						  sk->sk_allocation,
1286
						  first_skb);
1287 1288
			if (!skb)
				goto wait_for_memory;
L
Linus Torvalds 已提交
1289

1290
			process_backlog = true;
1291 1292 1293
			/*
			 * Check whether we can use HW checksum.
			 */
1294
			if (sk_check_csum_caps(sk))
1295
				skb->ip_summed = CHECKSUM_PARTIAL;
L
Linus Torvalds 已提交
1296

1297 1298 1299
			skb_entail(sk, skb);
			copy = size_goal;
			max = size_goal;
1300

1301 1302 1303 1304 1305 1306 1307
			/* All packets are restored as if they have
			 * already been sent. skb_mstamp isn't set to
			 * avoid wrong rtt estimation.
			 */
			if (tp->repair)
				TCP_SKB_CB(skb)->sacked |= TCPCB_REPAIRED;
		}
L
Linus Torvalds 已提交
1308

1309
		/* Try to append data to the end of skb. */
A
Al Viro 已提交
1310 1311
		if (copy > msg_data_left(msg))
			copy = msg_data_left(msg);
1312 1313 1314 1315 1316 1317 1318 1319

		/* 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;
W
Willem de Bruijn 已提交
1320
		} else if (!uarg || !uarg->zerocopy) {
1321 1322 1323 1324 1325 1326
			bool merge = true;
			int i = skb_shinfo(skb)->nr_frags;
			struct page_frag *pfrag = sk_page_frag(sk);

			if (!sk_page_frag_refill(sk, pfrag))
				goto wait_for_memory;
1327

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

1337 1338 1339 1340
			copy = min_t(int, copy, pfrag->size - pfrag->offset);

			if (!sk_wmem_schedule(sk, copy))
				goto wait_for_memory;
L
Linus Torvalds 已提交
1341

1342 1343 1344 1345 1346 1347
			err = skb_copy_to_page_nocache(sk, &msg->msg_iter, skb,
						       pfrag->page,
						       pfrag->offset,
						       copy);
			if (err)
				goto do_error;
L
Linus Torvalds 已提交
1348

1349 1350 1351 1352 1353 1354
			/* Update the skb. */
			if (merge) {
				skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy);
			} else {
				skb_fill_page_desc(skb, i, pfrag->page,
						   pfrag->offset, copy);
1355
				page_ref_inc(pfrag->page);
1356
			}
1357
			pfrag->offset += copy;
W
Willem de Bruijn 已提交
1358 1359 1360 1361 1362 1363 1364
		} else {
			err = skb_zerocopy_iter_stream(sk, skb, msg, copy, uarg);
			if (err == -EMSGSIZE || err == -EEXIST)
				goto new_segment;
			if (err < 0)
				goto do_error;
			copy = err;
1365 1366 1367 1368 1369 1370 1371 1372
		}

		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
1373

1374
		copied += copy;
A
Al Viro 已提交
1375
		if (!msg_data_left(msg)) {
1376 1377
			if (unlikely(flags & MSG_EOR))
				TCP_SKB_CB(skb)->eor = 1;
1378 1379
			goto out;
		}
L
Linus Torvalds 已提交
1380

1381
		if (skb->len < max || (flags & MSG_OOB) || unlikely(tp->repair))
L
Linus Torvalds 已提交
1382 1383
			continue;

1384 1385 1386 1387 1388 1389 1390
		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
1391
wait_for_sndbuf:
1392
		set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
L
Linus Torvalds 已提交
1393
wait_for_memory:
1394 1395 1396
		if (copied)
			tcp_push(sk, flags & ~MSG_MORE, mss_now,
				 TCP_NAGLE_PUSH, size_goal);
L
Linus Torvalds 已提交
1397

1398 1399
		err = sk_stream_wait_memory(sk, &timeo);
		if (err != 0)
1400
			goto do_error;
L
Linus Torvalds 已提交
1401

1402
		mss_now = tcp_send_mss(sk, &size_goal, flags);
L
Linus Torvalds 已提交
1403 1404 1405
	}

out:
1406 1407
	if (copied) {
		tcp_tx_timestamp(sk, sockc.tsflags, tcp_write_queue_tail(sk));
E
Eric Dumazet 已提交
1408
		tcp_push(sk, flags, mss_now, tp->nonagle, size_goal);
1409
	}
1410
out_nopush:
W
Willem de Bruijn 已提交
1411
	sock_zerocopy_put(uarg);
1412
	return copied + copied_syn;
L
Linus Torvalds 已提交
1413 1414 1415

do_fault:
	if (!skb->len) {
1416 1417 1418 1419 1420
		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);
1421
		sk_wmem_free_skb(sk, skb);
L
Linus Torvalds 已提交
1422 1423 1424
	}

do_error:
1425
	if (copied + copied_syn)
L
Linus Torvalds 已提交
1426 1427
		goto out;
out_err:
W
Willem de Bruijn 已提交
1428
	sock_zerocopy_put_abort(uarg);
L
Linus Torvalds 已提交
1429
	err = sk_stream_error(sk, flags, err);
1430
	/* make sure we wake any epoll edge trigger waiter */
1431 1432
	if (unlikely(skb_queue_len(&sk->sk_write_queue) == 0 &&
		     err == -EAGAIN)) {
1433
		sk->sk_write_space(sk);
1434 1435
		tcp_chrono_stop(sk, TCP_CHRONO_SNDBUF_LIMITED);
	}
L
Linus Torvalds 已提交
1436 1437
	return err;
}
1438
EXPORT_SYMBOL_GPL(tcp_sendmsg_locked);
1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449

int tcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
{
	int ret;

	lock_sock(sk);
	ret = tcp_sendmsg_locked(sk, msg, size);
	release_sock(sk);

	return ret;
}
E
Eric Dumazet 已提交
1450
EXPORT_SYMBOL(tcp_sendmsg);
L
Linus Torvalds 已提交
1451 1452 1453 1454 1455 1456

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

1457
static int tcp_recv_urg(struct sock *sk, struct msghdr *msg, int len, int flags)
L
Linus Torvalds 已提交
1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480
{
	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
1481
				err = memcpy_to_msg(msg, &c, 1);
L
Linus Torvalds 已提交
1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500
			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
1501 1502 1503 1504 1505 1506 1507 1508
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) {
1509
		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
P
Pavel Emelyanov 已提交
1510 1511 1512 1513 1514 1515 1516 1517 1518
		if (err)
			break;

		copied += skb->len;
	}

	return err ?: copied;
}

L
Linus Torvalds 已提交
1519 1520 1521 1522 1523 1524
/* 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.
 */
1525
static void tcp_cleanup_rbuf(struct sock *sk, int copied)
L
Linus Torvalds 已提交
1526 1527
{
	struct tcp_sock *tp = tcp_sk(sk);
E
Eric Dumazet 已提交
1528
	bool time_to_ack = false;
L
Linus Torvalds 已提交
1529 1530 1531

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

1532
	WARN(skb && !before(tp->copied_seq, TCP_SKB_CB(skb)->end_seq),
J
Joe Perches 已提交
1533
	     "cleanup rbuf bug: copied %X seq %X rcvnxt %X\n",
1534
	     tp->copied_seq, TCP_SKB_CB(skb)->end_seq, tp->rcv_nxt);
L
Linus Torvalds 已提交
1535

1536 1537
	if (inet_csk_ack_scheduled(sk)) {
		const struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
1538 1539
		   /* Delayed ACKs frequently hit locked sockets during bulk
		    * receive. */
1540
		if (icsk->icsk_ack.blocked ||
L
Linus Torvalds 已提交
1541
		    /* Once-per-two-segments ACK was not sent by tcp_input.c */
1542
		    tp->rcv_nxt - tp->rcv_wup > icsk->icsk_ack.rcv_mss ||
L
Linus Torvalds 已提交
1543 1544 1545 1546 1547 1548
		    /*
		     * 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.
		     */
1549 1550 1551 1552 1553
		    (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
1554
			time_to_ack = true;
L
Linus Torvalds 已提交
1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575
	}

	/* 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
1576
				time_to_ack = true;
L
Linus Torvalds 已提交
1577 1578 1579 1580 1581 1582
		}
	}
	if (time_to_ack)
		tcp_send_ack(sk);
}

1583
static struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off)
L
Linus Torvalds 已提交
1584 1585 1586 1587
{
	struct sk_buff *skb;
	u32 offset;

1588
	while ((skb = skb_peek(&sk->sk_receive_queue)) != NULL) {
L
Linus Torvalds 已提交
1589
		offset = seq - TCP_SKB_CB(skb)->seq;
1590 1591
		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
1592
			offset--;
1593
		}
1594
		if (offset < skb->len || (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)) {
L
Linus Torvalds 已提交
1595 1596 1597
			*off = offset;
			return skb;
		}
1598 1599 1600 1601
		/* 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
1602
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630
	}
	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) {
1631 1632
			int used;
			size_t len;
L
Linus Torvalds 已提交
1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643

			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);
1644
			if (used <= 0) {
1645 1646 1647 1648
				if (!copied)
					copied = used;
				break;
			} else if (used <= len) {
L
Linus Torvalds 已提交
1649 1650 1651 1652
				seq += used;
				copied += used;
				offset += used;
			}
1653
			/* If recv_actor drops the lock (e.g. TCP splice
1654 1655 1656 1657
			 * receive) the skb pointer might be invalid when
			 * getting here: tcp_collapse might have deleted it
			 * while aggregating skbs from the socket queue.
			 */
1658 1659
			skb = tcp_recv_skb(sk, seq - 1, &offset);
			if (!skb)
L
Linus Torvalds 已提交
1660
				break;
1661 1662 1663 1664 1665
			/* 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
1666
		}
1667
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
D
Dan Williams 已提交
1668
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1669 1670 1671
			++seq;
			break;
		}
D
Dan Williams 已提交
1672
		sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1673 1674
		if (!desc->count)
			break;
1675
		tp->copied_seq = seq;
L
Linus Torvalds 已提交
1676 1677 1678 1679 1680 1681
	}
	tp->copied_seq = seq;

	tcp_rcv_space_adjust(sk);

	/* Clean up data we have read: This will do ACK frames. */
1682 1683
	if (copied > 0) {
		tcp_recv_skb(sk, seq, &offset);
1684
		tcp_cleanup_rbuf(sk, copied);
1685
	}
L
Linus Torvalds 已提交
1686 1687
	return copied;
}
E
Eric Dumazet 已提交
1688
EXPORT_SYMBOL(tcp_read_sock);
L
Linus Torvalds 已提交
1689

1690 1691 1692 1693 1694 1695
int tcp_peek_len(struct socket *sock)
{
	return tcp_inq(sock->sk);
}
EXPORT_SYMBOL(tcp_peek_len);

1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750
static void tcp_update_recv_tstamps(struct sk_buff *skb,
				    struct scm_timestamping *tss)
{
	if (skb->tstamp)
		tss->ts[0] = ktime_to_timespec(skb->tstamp);
	else
		tss->ts[0] = (struct timespec) {0};

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

/* Similar to __sock_recv_timestamp, but does not require an skb */
void tcp_recv_timestamp(struct msghdr *msg, const struct sock *sk,
			struct scm_timestamping *tss)
{
	struct timeval tv;
	bool has_timestamping = false;

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

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

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

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

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

L
Linus Torvalds 已提交
1751 1752 1753 1754 1755 1756 1757 1758
/*
 *	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.
 */

1759 1760
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
1761 1762 1763 1764 1765 1766 1767 1768 1769
{
	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;
1770
	struct sk_buff *skb, *last;
I
Ilpo Järvinen 已提交
1771
	u32 urg_hole = 0;
1772 1773
	struct scm_timestamping tss;
	bool has_tss = false;
L
Linus Torvalds 已提交
1774

1775
	if (unlikely(flags & MSG_ERRQUEUE))
1776
		return inet_recv_error(sk, msg, len, addr_len);
1777

1778 1779 1780
	if (sk_can_busy_loop(sk) && skb_queue_empty(&sk->sk_receive_queue) &&
	    (sk->sk_state == TCP_ESTABLISHED))
		sk_busy_loop(sk, nonblock);
1781

L
Linus Torvalds 已提交
1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793
	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
1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808
	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
1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831
	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. */

1832
		last = skb_peek_tail(&sk->sk_receive_queue);
1833
		skb_queue_walk(&sk->sk_receive_queue, skb) {
1834
			last = skb;
L
Linus Torvalds 已提交
1835 1836 1837
			/* Now that we have two receive queues this
			 * shouldn't happen.
			 */
1838
			if (WARN(before(*seq, TCP_SKB_CB(skb)->seq),
J
Joe Perches 已提交
1839 1840 1841
				 "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
1842
				break;
1843

L
Linus Torvalds 已提交
1844
			offset = *seq - TCP_SKB_CB(skb)->seq;
1845 1846
			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
1847
				offset--;
1848
			}
L
Linus Torvalds 已提交
1849 1850
			if (offset < skb->len)
				goto found_ok_skb;
1851
			if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1852
				goto found_fin_ok;
J
Joe Perches 已提交
1853 1854 1855
			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);
1856
		}
L
Linus Torvalds 已提交
1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867

		/* 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 ||
1868
			    signal_pending(current))
L
Linus Torvalds 已提交
1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903
				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;
			}
		}

1904
		tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1905 1906 1907 1908 1909

		if (copied >= target) {
			/* Do not sleep, just process backlog. */
			release_sock(sk);
			lock_sock(sk);
1910 1911 1912
		} else {
			sk_wait_data(sk, &timeo, last);
		}
L
Linus Torvalds 已提交
1913

I
Ilpo Järvinen 已提交
1914 1915
		if ((flags & MSG_PEEK) &&
		    (peek_seq - copied - urg_hole != tp->copied_seq)) {
1916 1917 1918
			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
1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935
			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
1936
						urg_hole++;
L
Linus Torvalds 已提交
1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947
						offset++;
						used--;
						if (!used)
							goto skip_copy;
					}
				} else
					used = urg_offset;
			}
		}

		if (!(flags & MSG_TRUNC)) {
1948
			err = skb_copy_datagram_msg(skb, offset, msg, used);
D
Dan Williams 已提交
1949 1950 1951 1952 1953
			if (err) {
				/* Exception. Bailout! */
				if (!copied)
					copied = -EFAULT;
				break;
L
Linus Torvalds 已提交
1954 1955 1956 1957 1958 1959 1960 1961 1962 1963
			}
		}

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

		tcp_rcv_space_adjust(sk);

skip_copy:
1964
		if (tp->urg_data && after(tp->copied_seq, tp->urg_seq)) {
L
Linus Torvalds 已提交
1965
			tp->urg_data = 0;
1966 1967
			tcp_fast_path_check(sk);
		}
L
Linus Torvalds 已提交
1968 1969 1970
		if (used + offset < skb->len)
			continue;

1971 1972 1973 1974
		if (TCP_SKB_CB(skb)->has_rxtstamp) {
			tcp_update_recv_tstamps(skb, &tss);
			has_tss = true;
		}
1975
		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
L
Linus Torvalds 已提交
1976
			goto found_fin_ok;
D
Dan Williams 已提交
1977 1978
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1979 1980 1981 1982 1983
		continue;

	found_fin_ok:
		/* Process the FIN. */
		++*seq;
D
Dan Williams 已提交
1984 1985
		if (!(flags & MSG_PEEK))
			sk_eat_skb(sk, skb);
L
Linus Torvalds 已提交
1986 1987 1988 1989 1990 1991 1992
		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
	 */

1993 1994 1995
	if (has_tss)
		tcp_recv_timestamp(msg, sk, &tss);

L
Linus Torvalds 已提交
1996
	/* Clean up data we have read: This will do ACK frames. */
1997
	tcp_cleanup_rbuf(sk, copied);
L
Linus Torvalds 已提交
1998 1999 2000 2001 2002 2003 2004 2005 2006

	release_sock(sk);
	return copied;

out:
	release_sock(sk);
	return err;

recv_urg:
2007
	err = tcp_recv_urg(sk, msg, len, flags);
L
Linus Torvalds 已提交
2008
	goto out;
P
Pavel Emelyanov 已提交
2009 2010 2011 2012

recv_sndq:
	err = tcp_peek_sndq(sk, msg, len);
	goto out;
L
Linus Torvalds 已提交
2013
}
E
Eric Dumazet 已提交
2014
EXPORT_SYMBOL(tcp_recvmsg);
L
Linus Torvalds 已提交
2015

I
Ilpo Järvinen 已提交
2016 2017 2018 2019 2020 2021 2022
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
2023
			TCP_INC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2024 2025 2026 2027
		break;

	case TCP_CLOSE:
		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2028
			TCP_INC_STATS(sock_net(sk), TCP_MIB_ESTABRESETS);
I
Ilpo Järvinen 已提交
2029 2030 2031 2032

		sk->sk_prot->unhash(sk);
		if (inet_csk(sk)->icsk_bind_hash &&
		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
2033
			inet_put_port(sk);
I
Ilpo Järvinen 已提交
2034 2035
		/* fall through */
	default:
2036
		if (oldstate == TCP_ESTABLISHED)
P
Pavel Emelyanov 已提交
2037
			TCP_DEC_STATS(sock_net(sk), TCP_MIB_CURRESTAB);
I
Ilpo Järvinen 已提交
2038 2039 2040 2041 2042
	}

	/* Change state AFTER socket is unhashed to avoid closed
	 * socket sitting in hash tables.
	 */
2043
	sk_state_store(sk, state);
I
Ilpo Järvinen 已提交
2044 2045

#ifdef STATE_TRACE
2046
	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n", sk, statename[oldstate], statename[state]);
I
Ilpo Järvinen 已提交
2047 2048 2049 2050
#endif
}
EXPORT_SYMBOL_GPL(tcp_set_state);

L
Linus Torvalds 已提交
2051 2052 2053 2054 2055 2056 2057
/*
 *	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.
 */

2058
static const unsigned char new_state[16] = {
L
Linus Torvalds 已提交
2059
  /* current state:        new state:      action:	*/
2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072
  [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
2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086
};

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
2087
 *	that we don't receive shut down or sock_set_flag(sk, SOCK_DEAD).
L
Linus Torvalds 已提交
2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107
 */

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
2108
EXPORT_SYMBOL(tcp_shutdown);
L
Linus Torvalds 已提交
2109

A
Arun Sharma 已提交
2110 2111 2112 2113 2114 2115 2116
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);

2117 2118 2119 2120
	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
2121 2122 2123
	return too_many_orphans || out_of_socket_memory;
}

L
Linus Torvalds 已提交
2124 2125 2126 2127
void tcp_close(struct sock *sk, long timeout)
{
	struct sk_buff *skb;
	int data_was_unread = 0;
H
Herbert Xu 已提交
2128
	int state;
L
Linus Torvalds 已提交
2129 2130 2131 2132 2133 2134 2135 2136

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

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

		/* Special case. */
2137
		inet_csk_listen_stop(sk);
L
Linus Torvalds 已提交
2138 2139 2140 2141 2142 2143 2144 2145 2146

		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) {
2147 2148 2149 2150
		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
2151 2152 2153 2154
		data_was_unread += len;
		__kfree_skb(skb);
	}

2155
	sk_mem_reclaim(sk);
L
Linus Torvalds 已提交
2156

2157 2158 2159 2160
	/* If socket has been already reset (e.g. in tcp_reset()) - kill it. */
	if (sk->sk_state == TCP_CLOSE)
		goto adjudge_to_death;

2161 2162 2163 2164 2165 2166
	/* 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
2167
	 */
P
Pavel Emelyanov 已提交
2168 2169 2170
	if (unlikely(tcp_sk(sk)->repair)) {
		sk->sk_prot->disconnect(sk, 0);
	} else if (data_was_unread) {
L
Linus Torvalds 已提交
2171
		/* Unread data was tossed, zap the connection. */
2172
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONCLOSE);
L
Linus Torvalds 已提交
2173
		tcp_set_state(sk, TCP_CLOSE);
2174
		tcp_send_active_reset(sk, sk->sk_allocation);
L
Linus Torvalds 已提交
2175 2176 2177
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
2178
		NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
L
Linus Torvalds 已提交
2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203
	} 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
2204 2205 2206 2207
		 * 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
2208 2209 2210 2211 2212 2213 2214
		 */
		tcp_send_fin(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
H
Herbert Xu 已提交
2215 2216 2217 2218
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

L
Linus Torvalds 已提交
2219 2220 2221 2222 2223
	/* 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
2224
	 *  to finish close. No need to check for user refs.
L
Linus Torvalds 已提交
2225 2226 2227
	 */
	local_bh_disable();
	bh_lock_sock(sk);
2228
	WARN_ON(sock_owned_by_user(sk));
L
Linus Torvalds 已提交
2229

H
Herbert Xu 已提交
2230 2231
	percpu_counter_inc(sk->sk_prot->orphan_count);

H
Herbert Xu 已提交
2232 2233 2234
	/* 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
2235 2236 2237 2238

	/*	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.
2239
	 *	We use a 1 minute timeout (about the same as BSD) then kill
L
Linus Torvalds 已提交
2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254
	 *	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);
2255
			__NET_INC_STATS(sock_net(sk),
2256
					LINUX_MIB_TCPABORTONLINGER);
L
Linus Torvalds 已提交
2257
		} else {
2258
			const int tmo = tcp_fin_time(sk);
L
Linus Torvalds 已提交
2259 2260

			if (tmo > TCP_TIMEWAIT_LEN) {
2261 2262
				inet_csk_reset_keepalive_timer(sk,
						tmo - TCP_TIMEWAIT_LEN);
L
Linus Torvalds 已提交
2263 2264 2265 2266 2267 2268 2269
			} else {
				tcp_time_wait(sk, TCP_FIN_WAIT2, tmo);
				goto out;
			}
		}
	}
	if (sk->sk_state != TCP_CLOSE) {
2270
		sk_mem_reclaim(sk);
A
Arun Sharma 已提交
2271
		if (tcp_check_oom(sk, 0)) {
L
Linus Torvalds 已提交
2272 2273
			tcp_set_state(sk, TCP_CLOSE);
			tcp_send_active_reset(sk, GFP_ATOMIC);
2274
			__NET_INC_STATS(sock_net(sk),
2275
					LINUX_MIB_TCPABORTONMEMORY);
L
Linus Torvalds 已提交
2276 2277 2278
		}
	}

2279 2280 2281 2282 2283 2284
	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.
		 */
2285
		if (req)
2286
			reqsk_fastopen_remove(sk, req, false);
2287
		inet_csk_destroy_sock(sk);
2288
	}
L
Linus Torvalds 已提交
2289 2290 2291 2292 2293 2294 2295
	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}
E
Eric Dumazet 已提交
2296
EXPORT_SYMBOL(tcp_close);
L
Linus Torvalds 已提交
2297 2298 2299

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

E
Eric Dumazet 已提交
2300
static inline bool tcp_need_reset(int state)
L
Linus Torvalds 已提交
2301 2302 2303 2304 2305 2306 2307 2308 2309
{
	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);
2310
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2311 2312 2313 2314 2315 2316 2317 2318 2319
	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) {
2320
		inet_csk_listen_stop(sk);
P
Pavel Emelyanov 已提交
2321 2322
	} else if (unlikely(tp->repair)) {
		sk->sk_err = ECONNABORTED;
L
Linus Torvalds 已提交
2323 2324 2325
	} 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
2326
		/* The last check adjusts for discrepancy of Linux wrt. RFC
L
Linus Torvalds 已提交
2327 2328 2329 2330 2331 2332 2333 2334 2335
		 * 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);
2336
	tcp_write_queue_purge(sk);
2337
	tcp_fastopen_active_disable_ofo_check(sk);
2338
	skb_rbtree_purge(&tp->out_of_order_queue);
L
Linus Torvalds 已提交
2339

E
Eric Dumazet 已提交
2340
	inet->inet_dport = 0;
L
Linus Torvalds 已提交
2341 2342 2343 2344 2345 2346

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

	sk->sk_shutdown = 0;
	sock_reset_flag(sk, SOCK_DONE);
2347
	tp->srtt_us = 0;
2348 2349
	tp->write_seq += tp->max_window + 2;
	if (tp->write_seq == 0)
L
Linus Torvalds 已提交
2350
		tp->write_seq = 1;
2351
	icsk->icsk_backoff = 0;
L
Linus Torvalds 已提交
2352
	tp->snd_cwnd = 2;
2353
	icsk->icsk_probes_out = 0;
L
Linus Torvalds 已提交
2354
	tp->packets_out = 0;
I
Ilpo Järvinen 已提交
2355
	tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
L
Linus Torvalds 已提交
2356
	tp->snd_cwnd_cnt = 0;
2357
	tp->window_clamp = 0;
2358
	tcp_set_ca_state(sk, TCP_CA_Open);
L
Linus Torvalds 已提交
2359
	tcp_clear_retrans(tp);
2360
	inet_csk_delack_init(sk);
2361 2362 2363 2364
	/* 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;
2365
	tcp_init_send_head(sk);
2366
	memset(&tp->rx_opt, 0, sizeof(tp->rx_opt));
L
Linus Torvalds 已提交
2367
	__sk_dst_reset(sk);
2368 2369
	dst_release(sk->sk_rx_dst);
	sk->sk_rx_dst = NULL;
2370
	tcp_saved_syn_free(tp);
L
Linus Torvalds 已提交
2371

2372 2373 2374 2375
	/* Clean up fastopen related fields */
	tcp_free_fastopen_req(tp);
	inet->defer_connect = 0;

E
Eric Dumazet 已提交
2376
	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
L
Linus Torvalds 已提交
2377 2378 2379 2380

	sk->sk_error_report(sk);
	return err;
}
E
Eric Dumazet 已提交
2381
EXPORT_SYMBOL(tcp_disconnect);
L
Linus Torvalds 已提交
2382

E
Eric Dumazet 已提交
2383
static inline bool tcp_can_repair_sock(const struct sock *sk)
P
Pavel Emelyanov 已提交
2384
{
2385
	return ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN) &&
2386
		(sk->sk_state != TCP_LISTEN);
P
Pavel Emelyanov 已提交
2387 2388
}

2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420
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;
}

2421
static int tcp_repair_options_est(struct sock *sk,
2422
		struct tcp_repair_opt __user *optbuf, unsigned int len)
2423
{
2424
	struct tcp_sock *tp = tcp_sk(sk);
2425
	struct tcp_repair_opt opt;
2426

2427 2428
	while (len >= sizeof(opt)) {
		if (copy_from_user(&opt, optbuf, sizeof(opt)))
2429 2430 2431
			return -EFAULT;

		optbuf++;
2432
		len -= sizeof(opt);
2433

2434 2435 2436
		switch (opt.opt_code) {
		case TCPOPT_MSS:
			tp->rx_opt.mss_clamp = opt.opt_val;
2437
			tcp_mtup_init(sk);
2438
			break;
2439
		case TCPOPT_WINDOW:
2440 2441 2442 2443
			{
				u16 snd_wscale = opt.opt_val & 0xFFFF;
				u16 rcv_wscale = opt.opt_val >> 16;

2444
				if (snd_wscale > TCP_MAX_WSCALE || rcv_wscale > TCP_MAX_WSCALE)
2445
					return -EFBIG;
2446

2447 2448 2449 2450
				tp->rx_opt.snd_wscale = snd_wscale;
				tp->rx_opt.rcv_wscale = rcv_wscale;
				tp->rx_opt.wscale_ok = 1;
			}
2451 2452
			break;
		case TCPOPT_SACK_PERM:
2453 2454 2455
			if (opt.opt_val != 0)
				return -EINVAL;

2456 2457 2458 2459 2460
			tp->rx_opt.sack_ok |= TCP_SACK_SEEN;
			if (sysctl_tcp_fack)
				tcp_enable_fack(tp);
			break;
		case TCPOPT_TIMESTAMP:
2461 2462 2463
			if (opt.opt_val != 0)
				return -EINVAL;

2464 2465 2466 2467 2468 2469 2470 2471
			tp->rx_opt.tstamp_ok = 1;
			break;
		}
	}

	return 0;
}

L
Linus Torvalds 已提交
2472 2473 2474
/*
 *	Socket option code for TCP.
 */
2475
static int do_tcp_setsockopt(struct sock *sk, int level,
2476
		int optname, char __user *optval, unsigned int optlen)
L
Linus Torvalds 已提交
2477 2478
{
	struct tcp_sock *tp = tcp_sk(sk);
2479
	struct inet_connection_sock *icsk = inet_csk(sk);
2480
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2481 2482 2483
	int val;
	int err = 0;

2484 2485 2486
	/* These are data/string values, all the others are ints */
	switch (optname) {
	case TCP_CONGESTION: {
2487 2488 2489 2490 2491 2492
		char name[TCP_CA_NAME_MAX];

		if (optlen < 1)
			return -EINVAL;

		val = strncpy_from_user(name, optval,
2493
					min_t(long, TCP_CA_NAME_MAX-1, optlen));
2494 2495 2496 2497 2498
		if (val < 0)
			return -EFAULT;
		name[val] = 0;

		lock_sock(sk);
2499
		err = tcp_set_congestion_control(sk, name, true, true);
2500 2501 2502
		release_sock(sk);
		return err;
	}
D
Dave Watson 已提交
2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520
	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;
	}
2521 2522 2523
	default:
		/* fallthru */
		break;
2524
	}
2525

L
Linus Torvalds 已提交
2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537
	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
2538 2539
		 * know which interface is going to be used
		 */
2540
		if (val && (val < TCP_MIN_MSS || val > MAX_TCP_WINDOW)) {
L
Linus Torvalds 已提交
2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557
			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;
2558
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2559 2560 2561 2562 2563
		} else {
			tp->nonagle &= ~TCP_NAGLE_OFF;
		}
		break;

A
Andreas Petlund 已提交
2564 2565 2566 2567 2568 2569 2570
	case TCP_THIN_LINEAR_TIMEOUTS:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->thin_lto = val;
		break;

A
Andreas Petlund 已提交
2571 2572 2573 2574 2575
	case TCP_THIN_DUPACK:
		if (val < 0 || val > 1)
			err = -EINVAL;
		break;

P
Pavel Emelyanov 已提交
2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611
	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;

2612 2613 2614 2615
	case TCP_REPAIR_OPTIONS:
		if (!tp->repair)
			err = -EINVAL;
		else if (sk->sk_state == TCP_ESTABLISHED)
2616
			err = tcp_repair_options_est(sk,
2617 2618
					(struct tcp_repair_opt __user *)optval,
					optlen);
2619 2620 2621 2622
		else
			err = -EPERM;
		break;

L
Linus Torvalds 已提交
2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640
	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;
2641
			tcp_push_pending_frames(sk);
L
Linus Torvalds 已提交
2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652
		}
		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))) {
2653
				u32 elapsed = keepalive_time_elapsed(tp);
L
Linus Torvalds 已提交
2654 2655 2656 2657
				if (tp->keepalive_time > elapsed)
					elapsed = tp->keepalive_time - elapsed;
				else
					elapsed = 0;
2658
				inet_csk_reset_keepalive_timer(sk, elapsed);
L
Linus Torvalds 已提交
2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677
			}
		}
		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
2678
			icsk->icsk_syn_retries = val;
L
Linus Torvalds 已提交
2679 2680
		break;

2681 2682 2683 2684 2685 2686 2687
	case TCP_SAVE_SYN:
		if (val < 0 || val > 1)
			err = -EINVAL;
		else
			tp->save_syn = val;
		break;

L
Linus Torvalds 已提交
2688 2689 2690
	case TCP_LINGER2:
		if (val < 0)
			tp->linger2 = -1;
2691
		else if (val > net->ipv4.sysctl_tcp_fin_timeout / HZ)
L
Linus Torvalds 已提交
2692 2693 2694 2695 2696 2697
			tp->linger2 = 0;
		else
			tp->linger2 = val * HZ;
		break;

	case TCP_DEFER_ACCEPT:
2698 2699 2700 2701
		/* 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
2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717
		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) {
2718
			icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2719
		} else {
2720
			icsk->icsk_ack.pingpong = 0;
L
Linus Torvalds 已提交
2721 2722
			if ((1 << sk->sk_state) &
			    (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT) &&
2723 2724
			    inet_csk_ack_scheduled(sk)) {
				icsk->icsk_ack.pending |= ICSK_ACK_PUSHED;
2725
				tcp_cleanup_rbuf(sk, 1);
L
Linus Torvalds 已提交
2726
				if (!(val & 1))
2727
					icsk->icsk_ack.pingpong = 1;
L
Linus Torvalds 已提交
2728 2729 2730 2731
			}
		}
		break;

2732 2733
#ifdef CONFIG_TCP_MD5SIG
	case TCP_MD5SIG:
2734
	case TCP_MD5SIG_EXT:
2735
		/* Read the IP->Key mappings from userspace */
2736
		err = tp->af_specific->md5_parse(sk, optname, optval, optlen);
2737 2738
		break;
#endif
2739
	case TCP_USER_TIMEOUT:
2740
		/* Cap the max time in ms TCP will retry or probe the window
2741 2742
		 * before giving up and aborting (ETIMEDOUT) a connection.
		 */
2743 2744 2745 2746
		if (val < 0)
			err = -EINVAL;
		else
			icsk->icsk_user_timeout = msecs_to_jiffies(val);
2747
		break;
2748 2749 2750

	case TCP_FASTOPEN:
		if (val >= 0 && ((1 << sk->sk_state) & (TCPF_CLOSE |
2751
		    TCPF_LISTEN))) {
2752
			tcp_fastopen_init_key_once();
2753

2754
			fastopen_queue_tune(sk, val);
2755
		} else {
2756
			err = -EINVAL;
2757
		}
2758
		break;
W
Wei Wang 已提交
2759 2760 2761
	case TCP_FASTOPEN_CONNECT:
		if (val > 1 || val < 0) {
			err = -EINVAL;
2762
		} else if (net->ipv4.sysctl_tcp_fastopen & TFO_CLIENT_ENABLE) {
W
Wei Wang 已提交
2763 2764 2765 2766 2767 2768 2769 2770
			if (sk->sk_state == TCP_CLOSE)
				tp->fastopen_connect = val;
			else
				err = -EINVAL;
		} else {
			err = -EOPNOTSUPP;
		}
		break;
2771 2772 2773 2774
	case TCP_TIMESTAMP:
		if (!tp->repair)
			err = -EPERM;
		else
2775
			tp->tsoffset = val - tcp_time_stamp_raw();
2776
		break;
2777 2778 2779
	case TCP_REPAIR_WINDOW:
		err = tcp_repair_set_window(tp, optval, optlen);
		break;
2780 2781 2782 2783
	case TCP_NOTSENT_LOWAT:
		tp->notsent_lowat = val;
		sk->sk_write_space(sk);
		break;
L
Linus Torvalds 已提交
2784 2785 2786
	default:
		err = -ENOPROTOOPT;
		break;
2787 2788
	}

L
Linus Torvalds 已提交
2789 2790 2791 2792
	release_sock(sk);
	return err;
}

2793
int tcp_setsockopt(struct sock *sk, int level, int optname, char __user *optval,
2794
		   unsigned int optlen)
2795
{
2796
	const struct inet_connection_sock *icsk = inet_csk(sk);
2797 2798 2799 2800 2801 2802

	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
2803
EXPORT_SYMBOL(tcp_setsockopt);
2804 2805

#ifdef CONFIG_COMPAT
2806
int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
2807
			  char __user *optval, unsigned int optlen)
2808
{
2809 2810 2811
	if (level != SOL_TCP)
		return inet_csk_compat_setsockopt(sk, level, optname,
						  optval, optlen);
2812 2813
	return do_tcp_setsockopt(sk, level, optname, optval, optlen);
}
2814
EXPORT_SYMBOL(compat_tcp_setsockopt);
2815 2816
#endif

2817 2818 2819 2820 2821 2822 2823 2824 2825
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)
2826
			stats[i] += tcp_jiffies32 - tp->chrono_start;
2827 2828 2829 2830 2831 2832 2833 2834 2835
		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
2836
/* Return information about state of tcp endpoint in API format. */
2837
void tcp_get_info(struct sock *sk, struct tcp_info *info)
L
Linus Torvalds 已提交
2838
{
2839
	const struct tcp_sock *tp = tcp_sk(sk); /* iff sk_type == SOCK_STREAM */
2840
	const struct inet_connection_sock *icsk = inet_csk(sk);
2841
	u32 now;
2842
	u64 rate64;
2843
	bool slow;
2844
	u32 rate;
L
Linus Torvalds 已提交
2845 2846

	memset(info, 0, sizeof(*info));
2847 2848
	if (sk->sk_type != SOCK_STREAM)
		return;
L
Linus Torvalds 已提交
2849

2850 2851
	info->tcpi_state = sk_state_load(sk);

2852 2853 2854
	/* Report meaningful fields for all TCP states, including listeners */
	rate = READ_ONCE(sk->sk_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2855
	info->tcpi_pacing_rate = rate64;
2856 2857 2858

	rate = READ_ONCE(sk->sk_max_pacing_rate);
	rate64 = rate != ~0U ? rate : ~0ULL;
2859
	info->tcpi_max_pacing_rate = rate64;
2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872

	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;
	}
2873 2874 2875

	slow = lock_sock_fast(sk);

2876
	info->tcpi_ca_state = icsk->icsk_ca_state;
2877
	info->tcpi_retransmits = icsk->icsk_retransmits;
2878
	info->tcpi_probes = icsk->icsk_probes_out;
2879
	info->tcpi_backoff = icsk->icsk_backoff;
L
Linus Torvalds 已提交
2880 2881 2882

	if (tp->rx_opt.tstamp_ok)
		info->tcpi_options |= TCPI_OPT_TIMESTAMPS;
2883
	if (tcp_is_sack(tp))
L
Linus Torvalds 已提交
2884 2885 2886 2887 2888
		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;
2889
	}
L
Linus Torvalds 已提交
2890

E
Eric Dumazet 已提交
2891
	if (tp->ecn_flags & TCP_ECN_OK)
L
Linus Torvalds 已提交
2892
		info->tcpi_options |= TCPI_OPT_ECN;
E
Eric Dumazet 已提交
2893 2894
	if (tp->ecn_flags & TCP_ECN_SEEN)
		info->tcpi_options |= TCPI_OPT_ECN_SEEN;
Y
Yuchung Cheng 已提交
2895 2896
	if (tp->syn_data_acked)
		info->tcpi_options |= TCPI_OPT_SYN_DATA;
L
Linus Torvalds 已提交
2897

2898 2899
	info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
	info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
2900
	info->tcpi_snd_mss = tp->mss_cache;
2901
	info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
L
Linus Torvalds 已提交
2902

2903 2904 2905
	info->tcpi_unacked = tp->packets_out;
	info->tcpi_sacked = tp->sacked_out;

L
Linus Torvalds 已提交
2906 2907 2908 2909
	info->tcpi_lost = tp->lost_out;
	info->tcpi_retrans = tp->retrans_out;
	info->tcpi_fackets = tp->fackets_out;

2910
	now = tcp_jiffies32;
L
Linus Torvalds 已提交
2911
	info->tcpi_last_data_sent = jiffies_to_msecs(now - tp->lsndtime);
2912
	info->tcpi_last_data_recv = jiffies_to_msecs(now - icsk->icsk_ack.lrcvtime);
L
Linus Torvalds 已提交
2913 2914
	info->tcpi_last_ack_recv = jiffies_to_msecs(now - tp->rcv_tstamp);

2915
	info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
L
Linus Torvalds 已提交
2916
	info->tcpi_rcv_ssthresh = tp->rcv_ssthresh;
2917 2918
	info->tcpi_rtt = tp->srtt_us >> 3;
	info->tcpi_rttvar = tp->mdev_us >> 2;
L
Linus Torvalds 已提交
2919 2920 2921
	info->tcpi_snd_ssthresh = tp->snd_ssthresh;
	info->tcpi_advmss = tp->advmss;

2922
	info->tcpi_rcv_rtt = tp->rcv_rtt_est.rtt_us >> 3;
L
Linus Torvalds 已提交
2923 2924 2925
	info->tcpi_rcv_space = tp->rcvq_space.space;

	info->tcpi_total_retrans = tp->total_retrans;
2926

2927 2928
	info->tcpi_bytes_acked = tp->bytes_acked;
	info->tcpi_bytes_received = tp->bytes_received;
2929
	info->tcpi_notsent_bytes = max_t(int, 0, tp->write_seq - tp->snd_nxt);
2930
	tcp_get_info_chrono_stats(tp, info);
2931

2932 2933
	info->tcpi_segs_out = tp->segs_out;
	info->tcpi_segs_in = tp->segs_in;
2934 2935

	info->tcpi_min_rtt = tcp_min_rtt(tp);
2936 2937
	info->tcpi_data_segs_in = tp->data_segs_in;
	info->tcpi_data_segs_out = tp->data_segs_out;
Y
Yuchung Cheng 已提交
2938 2939

	info->tcpi_delivery_rate_app_limited = tp->rate_app_limited ? 1 : 0;
2940 2941
	rate64 = tcp_compute_delivery_rate(tp);
	if (rate64)
2942
		info->tcpi_delivery_rate = rate64;
2943
	unlock_sock_fast(sk, slow);
L
Linus Torvalds 已提交
2944 2945 2946
}
EXPORT_SYMBOL_GPL(tcp_get_info);

2947 2948 2949 2950 2951
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;
2952 2953
	u64 rate64;
	u32 rate;
2954

2955 2956 2957
	stats = alloc_skb(7 * nla_total_size_64bit(sizeof(u64)) +
			  3 * nla_total_size(sizeof(u32)) +
			  2 * nla_total_size(sizeof(u8)), GFP_ATOMIC);
2958 2959 2960 2961 2962 2963 2964 2965 2966 2967
	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);
2968 2969 2970 2971
	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);
2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985

	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);
2986 2987 2988
	return stats;
}

2989 2990
static int do_tcp_getsockopt(struct sock *sk, int level,
		int optname, char __user *optval, int __user *optlen)
L
Linus Torvalds 已提交
2991
{
2992
	struct inet_connection_sock *icsk = inet_csk(sk);
L
Linus Torvalds 已提交
2993
	struct tcp_sock *tp = tcp_sk(sk);
2994
	struct net *net = sock_net(sk);
L
Linus Torvalds 已提交
2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006
	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:
3007
		val = tp->mss_cache;
L
Linus Torvalds 已提交
3008 3009
		if (!val && ((1 << sk->sk_state) & (TCPF_CLOSE | TCPF_LISTEN)))
			val = tp->rx_opt.user_mss;
3010 3011
		if (tp->repair)
			val = tp->rx_opt.mss_clamp;
L
Linus Torvalds 已提交
3012 3013 3014 3015 3016 3017 3018 3019
		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
3020
		val = keepalive_time_when(tp) / HZ;
L
Linus Torvalds 已提交
3021 3022
		break;
	case TCP_KEEPINTVL:
E
Eric Dumazet 已提交
3023
		val = keepalive_intvl_when(tp) / HZ;
L
Linus Torvalds 已提交
3024 3025
		break;
	case TCP_KEEPCNT:
E
Eric Dumazet 已提交
3026
		val = keepalive_probes(tp);
L
Linus Torvalds 已提交
3027 3028
		break;
	case TCP_SYNCNT:
3029
		val = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_syn_retries;
L
Linus Torvalds 已提交
3030 3031 3032 3033
		break;
	case TCP_LINGER2:
		val = tp->linger2;
		if (val >= 0)
3034
			val = (val ? : net->ipv4.sysctl_tcp_fin_timeout) / HZ;
L
Linus Torvalds 已提交
3035 3036
		break;
	case TCP_DEFER_ACCEPT:
3037 3038
		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
3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057
		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;
	}
3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077
	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
3078
	case TCP_QUICKACK:
3079
		val = !icsk->icsk_ack.pingpong;
L
Linus Torvalds 已提交
3080
		break;
3081 3082 3083 3084 3085 3086 3087

	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;
3088
		if (copy_to_user(optval, icsk->icsk_ca_ops->name, len))
3089 3090
			return -EFAULT;
		return 0;
3091

D
Dave Watson 已提交
3092 3093 3094 3095
	case TCP_ULP:
		if (get_user(len, optlen))
			return -EFAULT;
		len = min_t(unsigned int, len, TCP_ULP_NAME_MAX);
3096 3097 3098 3099 3100
		if (!icsk->icsk_ulp_ops) {
			if (put_user(0, optlen))
				return -EFAULT;
			return 0;
		}
D
Dave Watson 已提交
3101 3102 3103 3104 3105 3106
		if (put_user(len, optlen))
			return -EFAULT;
		if (copy_to_user(optval, icsk->icsk_ulp_ops->name, len))
			return -EFAULT;
		return 0;

3107 3108 3109
	case TCP_THIN_LINEAR_TIMEOUTS:
		val = tp->thin_lto;
		break;
Y
Yuchung Cheng 已提交
3110

3111
	case TCP_THIN_DUPACK:
Y
Yuchung Cheng 已提交
3112
		val = 0;
3113
		break;
3114

P
Pavel Emelyanov 已提交
3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125
	case TCP_REPAIR:
		val = tp->repair;
		break;

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

3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147
	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
3148 3149 3150 3151 3152 3153 3154 3155 3156
	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;

3157 3158 3159
	case TCP_USER_TIMEOUT:
		val = jiffies_to_msecs(icsk->icsk_user_timeout);
		break;
3160 3161

	case TCP_FASTOPEN:
3162
		val = icsk->icsk_accept_queue.fastopenq.max_qlen;
3163 3164
		break;

W
Wei Wang 已提交
3165 3166 3167 3168
	case TCP_FASTOPEN_CONNECT:
		val = tp->fastopen_connect;
		break;

3169
	case TCP_TIMESTAMP:
3170
		val = tcp_time_stamp_raw() + tp->tsoffset;
3171
		break;
3172 3173 3174
	case TCP_NOTSENT_LOWAT:
		val = tp->notsent_lowat;
		break;
3175 3176 3177 3178 3179 3180 3181 3182 3183
	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) {
3184 3185 3186 3187 3188 3189 3190 3191 3192
			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];
3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210
			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
3211 3212
	default:
		return -ENOPROTOOPT;
3213
	}
L
Linus Torvalds 已提交
3214 3215 3216 3217 3218 3219 3220 3221

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

3222 3223 3224 3225 3226 3227 3228 3229 3230 3231
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
3232
EXPORT_SYMBOL(tcp_getsockopt);
3233 3234

#ifdef CONFIG_COMPAT
3235 3236
int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
			  char __user *optval, int __user *optlen)
3237
{
3238 3239 3240
	if (level != SOL_TCP)
		return inet_csk_compat_getsockopt(sk, level, optname,
						  optval, optlen);
3241 3242
	return do_tcp_getsockopt(sk, level, optname, optval, optlen);
}
3243
EXPORT_SYMBOL(compat_tcp_getsockopt);
3244
#endif
L
Linus Torvalds 已提交
3245

3246
#ifdef CONFIG_TCP_MD5SIG
E
Eric Dumazet 已提交
3247
static DEFINE_PER_CPU(struct tcp_md5sig_pool, tcp_md5sig_pool);
3248
static DEFINE_MUTEX(tcp_md5sig_mutex);
E
Eric Dumazet 已提交
3249
static bool tcp_md5sig_pool_populated = false;
3250

3251
static void __tcp_alloc_md5sig_pool(void)
3252
{
H
Herbert Xu 已提交
3253
	struct crypto_ahash *hash;
3254 3255
	int cpu;

H
Herbert Xu 已提交
3256
	hash = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);
3257
	if (IS_ERR(hash))
H
Herbert Xu 已提交
3258 3259
		return;

3260
	for_each_possible_cpu(cpu) {
3261
		void *scratch = per_cpu(tcp_md5sig_pool, cpu).scratch;
H
Herbert Xu 已提交
3262
		struct ahash_request *req;
3263

3264 3265 3266 3267 3268 3269 3270 3271 3272
		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
3273 3274 3275 3276 3277 3278 3279 3280 3281 3282
		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;
3283
	}
E
Eric Dumazet 已提交
3284 3285
	/* before setting tcp_md5sig_pool_populated, we must commit all writes
	 * to memory. See smp_rmb() in tcp_get_md5sig_pool()
3286 3287
	 */
	smp_wmb();
E
Eric Dumazet 已提交
3288
	tcp_md5sig_pool_populated = true;
3289 3290
}

3291
bool tcp_alloc_md5sig_pool(void)
3292
{
E
Eric Dumazet 已提交
3293
	if (unlikely(!tcp_md5sig_pool_populated)) {
3294 3295
		mutex_lock(&tcp_md5sig_mutex);

E
Eric Dumazet 已提交
3296
		if (!tcp_md5sig_pool_populated)
3297 3298 3299
			__tcp_alloc_md5sig_pool();

		mutex_unlock(&tcp_md5sig_mutex);
3300
	}
E
Eric Dumazet 已提交
3301
	return tcp_md5sig_pool_populated;
3302 3303 3304
}
EXPORT_SYMBOL(tcp_alloc_md5sig_pool);

E
Eric Dumazet 已提交
3305 3306 3307 3308 3309 3310 3311 3312 3313

/**
 *	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)
3314
{
E
Eric Dumazet 已提交
3315
	local_bh_disable();
3316

E
Eric Dumazet 已提交
3317 3318 3319 3320 3321
	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
3322 3323 3324 3325
	local_bh_enable();
	return NULL;
}
EXPORT_SYMBOL(tcp_get_md5sig_pool);
3326

3327
int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *hp,
3328
			  const struct sk_buff *skb, unsigned int header_len)
3329 3330 3331
{
	struct scatterlist sg;
	const struct tcphdr *tp = tcp_hdr(skb);
H
Herbert Xu 已提交
3332
	struct ahash_request *req = hp->md5_req;
3333 3334 3335
	unsigned int i;
	const unsigned int head_data_len = skb_headlen(skb) > header_len ?
					   skb_headlen(skb) - header_len : 0;
3336
	const struct skb_shared_info *shi = skb_shinfo(skb);
3337
	struct sk_buff *frag_iter;
3338 3339 3340 3341

	sg_init_table(&sg, 1);

	sg_set_buf(&sg, ((u8 *) tp) + header_len, head_data_len);
H
Herbert Xu 已提交
3342 3343
	ahash_request_set_crypt(req, &sg, NULL, head_data_len);
	if (crypto_ahash_update(req))
3344 3345 3346 3347
		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
3348 3349 3350 3351 3352
		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
3353 3354
		ahash_request_set_crypt(req, &sg, NULL, skb_frag_size(f));
		if (crypto_ahash_update(req))
3355 3356 3357
			return 1;
	}

3358 3359 3360 3361
	skb_walk_frags(skb, frag_iter)
		if (tcp_md5_hash_skb_data(hp, frag_iter, 0))
			return 1;

3362 3363 3364 3365
	return 0;
}
EXPORT_SYMBOL(tcp_md5_hash_skb_data);

3366
int tcp_md5_hash_key(struct tcp_md5sig_pool *hp, const struct tcp_md5sig_key *key)
3367 3368 3369 3370
{
	struct scatterlist sg;

	sg_init_one(&sg, key->key, key->keylen);
H
Herbert Xu 已提交
3371 3372
	ahash_request_set_crypt(hp->md5_req, &sg, NULL, key->keylen);
	return crypto_ahash_update(hp->md5_req);
3373 3374 3375
}
EXPORT_SYMBOL(tcp_md5_hash_key);

3376 3377
#endif

A
Andi Kleen 已提交
3378 3379
void tcp_done(struct sock *sk)
{
3380 3381
	struct request_sock *req = tcp_sk(sk)->fastopen_rsk;

3382
	if (sk->sk_state == TCP_SYN_SENT || sk->sk_state == TCP_SYN_RECV)
3383
		TCP_INC_STATS(sock_net(sk), TCP_MIB_ATTEMPTFAILS);
A
Andi Kleen 已提交
3384 3385 3386

	tcp_set_state(sk, TCP_CLOSE);
	tcp_clear_xmit_timers(sk);
3387
	if (req)
3388
		reqsk_fastopen_remove(sk, req, false);
A
Andi Kleen 已提交
3389 3390 3391 3392 3393 3394 3395 3396 3397 3398

	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);

3399 3400 3401
int tcp_abort(struct sock *sk, int err)
{
	if (!sk_fullsock(sk)) {
3402 3403 3404 3405 3406 3407 3408 3409 3410
		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;
		}
3411 3412 3413 3414 3415 3416
		return -EOPNOTSUPP;
	}

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

3417 3418 3419 3420 3421
	if (sk->sk_state == TCP_LISTEN) {
		tcp_set_state(sk, TCP_CLOSE);
		inet_csk_listen_stop(sk);
	}

3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442
	/* 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);

3443
extern struct tcp_congestion_ops tcp_reno;
L
Linus Torvalds 已提交
3444 3445 3446 3447

static __initdata unsigned long thash_entries;
static int __init set_thash_entries(char *str)
{
3448 3449
	ssize_t ret;

L
Linus Torvalds 已提交
3450 3451
	if (!str)
		return 0;
3452 3453 3454 3455 3456

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

L
Linus Torvalds 已提交
3457 3458 3459 3460
	return 1;
}
__setup("thash_entries=", set_thash_entries);

F
Fabian Frederick 已提交
3461
static void __init tcp_init_mem(void)
3462
{
E
Eric Dumazet 已提交
3463 3464
	unsigned long limit = nr_free_buffer_pages() / 16;

3465
	limit = max(limit, 128UL);
E
Eric Dumazet 已提交
3466 3467 3468
	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 % */
3469 3470
}

L
Linus Torvalds 已提交
3471 3472
void __init tcp_init(void)
{
3473
	int max_rshare, max_wshare, cnt;
3474
	unsigned long limit;
3475
	unsigned int i;
L
Linus Torvalds 已提交
3476

3477 3478
	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) >
		     FIELD_SIZEOF(struct sk_buff, cb));
L
Linus Torvalds 已提交
3479

3480 3481
	percpu_counter_init(&tcp_sockets_allocated, 0, GFP_KERNEL);
	percpu_counter_init(&tcp_orphan_count, 0, GFP_KERNEL);
3482
	inet_hashinfo_init(&tcp_hashinfo);
3483 3484 3485
	tcp_hashinfo.bind_bucket_cachep =
		kmem_cache_create("tcp_bind_bucket",
				  sizeof(struct inet_bind_bucket), 0,
3486
				  SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
L
Linus Torvalds 已提交
3487 3488 3489 3490 3491 3492

	/* Size and allocate the main established and bind bucket
	 * hash tables.
	 *
	 * The methodology is similar to that of the buffer cache.
	 */
3493
	tcp_hashinfo.ehash =
L
Linus Torvalds 已提交
3494
		alloc_large_system_hash("TCP established",
3495
					sizeof(struct inet_ehash_bucket),
L
Linus Torvalds 已提交
3496
					thash_entries,
E
Eric Dumazet 已提交
3497
					17, /* one slot per 128 KB of memory */
3498
					0,
L
Linus Torvalds 已提交
3499
					NULL,
3500
					&tcp_hashinfo.ehash_mask,
3501
					0,
3502
					thash_entries ? 0 : 512 * 1024);
E
Eric Dumazet 已提交
3503
	for (i = 0; i <= tcp_hashinfo.ehash_mask; i++)
3504
		INIT_HLIST_NULLS_HEAD(&tcp_hashinfo.ehash[i].chain, i);
E
Eric Dumazet 已提交
3505

3506 3507
	if (inet_ehash_locks_alloc(&tcp_hashinfo))
		panic("TCP: failed to alloc ehash_locks");
3508
	tcp_hashinfo.bhash =
L
Linus Torvalds 已提交
3509
		alloc_large_system_hash("TCP bind",
3510
					sizeof(struct inet_bind_hashbucket),
3511
					tcp_hashinfo.ehash_mask + 1,
E
Eric Dumazet 已提交
3512
					17, /* one slot per 128 KB of memory */
3513
					0,
3514
					&tcp_hashinfo.bhash_size,
L
Linus Torvalds 已提交
3515
					NULL,
3516
					0,
L
Linus Torvalds 已提交
3517
					64 * 1024);
3518
	tcp_hashinfo.bhash_size = 1U << tcp_hashinfo.bhash_size;
3519 3520 3521
	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
3522 3523
	}

E
Eric Dumazet 已提交
3524 3525 3526

	cnt = tcp_hashinfo.ehash_mask + 1;
	sysctl_tcp_max_orphans = cnt / 2;
L
Linus Torvalds 已提交
3527

3528
	tcp_init_mem();
3529
	/* Set per-socket limits to no more than 1/128 the pressure threshold */
E
Eric Dumazet 已提交
3530
	limit = nr_free_buffer_pages() << (PAGE_SHIFT - 7);
3531 3532
	max_wshare = min(4UL*1024*1024, limit);
	max_rshare = min(6UL*1024*1024, limit);
3533

3534
	sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
3535
	sysctl_tcp_wmem[1] = 16*1024;
3536
	sysctl_tcp_wmem[2] = max(64*1024, max_wshare);
3537

3538
	sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
3539
	sysctl_tcp_rmem[1] = 87380;
3540
	sysctl_tcp_rmem[2] = max(87380, max_rshare);
L
Linus Torvalds 已提交
3541

3542
	pr_info("Hash tables configured (established %u bind %u)\n",
J
Joe Perches 已提交
3543
		tcp_hashinfo.ehash_mask + 1, tcp_hashinfo.bhash_size);
3544

3545
	tcp_v4_init();
3546
	tcp_metrics_init();
3547
	BUG_ON(tcp_register_congestion_control(&tcp_reno) != 0);
E
Eric Dumazet 已提交
3548
	tcp_tasklet_init();
L
Linus Torvalds 已提交
3549
}