mirror of https://gitee.com/openkylin/linux.git
1601 lines
48 KiB
C
1601 lines
48 KiB
C
/*
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* INET An implementation of the TCP/IP protocol suite for the LINUX
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* operating system. INET is implemented using the BSD Socket
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* interface as the means of communication with the user level.
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*
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* Definitions for the TCP module.
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*
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* Version: @(#)tcp.h 1.0.5 05/23/93
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*
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* Authors: Ross Biro
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* Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#ifndef _TCP_H
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#define _TCP_H
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#define FASTRETRANS_DEBUG 1
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#include <linux/list.h>
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#include <linux/tcp.h>
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#include <linux/bug.h>
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#include <linux/slab.h>
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#include <linux/cache.h>
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#include <linux/percpu.h>
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#include <linux/skbuff.h>
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#include <linux/dmaengine.h>
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#include <linux/crypto.h>
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#include <linux/cryptohash.h>
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#include <linux/kref.h>
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#include <net/inet_connection_sock.h>
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#include <net/inet_timewait_sock.h>
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#include <net/inet_hashtables.h>
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#include <net/checksum.h>
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#include <net/request_sock.h>
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#include <net/sock.h>
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#include <net/snmp.h>
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#include <net/ip.h>
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#include <net/tcp_states.h>
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#include <net/inet_ecn.h>
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#include <net/dst.h>
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#include <linux/seq_file.h>
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#include <linux/memcontrol.h>
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extern struct inet_hashinfo tcp_hashinfo;
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extern struct percpu_counter tcp_orphan_count;
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extern void tcp_time_wait(struct sock *sk, int state, int timeo);
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#define MAX_TCP_HEADER (128 + MAX_HEADER)
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#define MAX_TCP_OPTION_SPACE 40
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/*
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* Never offer a window over 32767 without using window scaling. Some
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* poor stacks do signed 16bit maths!
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*/
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#define MAX_TCP_WINDOW 32767U
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/* Minimal accepted MSS. It is (60+60+8) - (20+20). */
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#define TCP_MIN_MSS 88U
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/* The least MTU to use for probing */
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#define TCP_BASE_MSS 512
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/* After receiving this amount of duplicate ACKs fast retransmit starts. */
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#define TCP_FASTRETRANS_THRESH 3
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/* Maximal reordering. */
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#define TCP_MAX_REORDERING 127
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/* Maximal number of ACKs sent quickly to accelerate slow-start. */
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#define TCP_MAX_QUICKACKS 16U
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/* urg_data states */
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#define TCP_URG_VALID 0x0100
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#define TCP_URG_NOTYET 0x0200
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#define TCP_URG_READ 0x0400
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#define TCP_RETR1 3 /*
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* This is how many retries it does before it
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* tries to figure out if the gateway is
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* down. Minimal RFC value is 3; it corresponds
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* to ~3sec-8min depending on RTO.
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*/
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#define TCP_RETR2 15 /*
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* This should take at least
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* 90 minutes to time out.
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* RFC1122 says that the limit is 100 sec.
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* 15 is ~13-30min depending on RTO.
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*/
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#define TCP_SYN_RETRIES 6 /* This is how many retries are done
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* when active opening a connection.
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* RFC1122 says the minimum retry MUST
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* be at least 180secs. Nevertheless
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* this value is corresponding to
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* 63secs of retransmission with the
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* current initial RTO.
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*/
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#define TCP_SYNACK_RETRIES 5 /* This is how may retries are done
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* when passive opening a connection.
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* This is corresponding to 31secs of
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* retransmission with the current
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* initial RTO.
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*/
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#define TCP_TIMEWAIT_LEN (60*HZ) /* how long to wait to destroy TIME-WAIT
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* state, about 60 seconds */
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#define TCP_FIN_TIMEOUT TCP_TIMEWAIT_LEN
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/* BSD style FIN_WAIT2 deadlock breaker.
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* It used to be 3min, new value is 60sec,
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* to combine FIN-WAIT-2 timeout with
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* TIME-WAIT timer.
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*/
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#define TCP_DELACK_MAX ((unsigned)(HZ/5)) /* maximal time to delay before sending an ACK */
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#if HZ >= 100
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#define TCP_DELACK_MIN ((unsigned)(HZ/25)) /* minimal time to delay before sending an ACK */
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#define TCP_ATO_MIN ((unsigned)(HZ/25))
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#else
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#define TCP_DELACK_MIN 4U
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#define TCP_ATO_MIN 4U
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#endif
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#define TCP_RTO_MAX ((unsigned)(120*HZ))
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#define TCP_RTO_MIN ((unsigned)(HZ/5))
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#define TCP_TIMEOUT_INIT ((unsigned)(1*HZ)) /* RFC6298 2.1 initial RTO value */
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#define TCP_TIMEOUT_FALLBACK ((unsigned)(3*HZ)) /* RFC 1122 initial RTO value, now
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* used as a fallback RTO for the
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* initial data transmission if no
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* valid RTT sample has been acquired,
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* most likely due to retrans in 3WHS.
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*/
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#define TCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ/2U)) /* Maximal interval between probes
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* for local resources.
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*/
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#define TCP_KEEPALIVE_TIME (120*60*HZ) /* two hours */
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#define TCP_KEEPALIVE_PROBES 9 /* Max of 9 keepalive probes */
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#define TCP_KEEPALIVE_INTVL (75*HZ)
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#define MAX_TCP_KEEPIDLE 32767
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#define MAX_TCP_KEEPINTVL 32767
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#define MAX_TCP_KEEPCNT 127
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#define MAX_TCP_SYNCNT 127
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#define TCP_SYNQ_INTERVAL (HZ/5) /* Period of SYNACK timer */
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#define TCP_PAWS_24DAYS (60 * 60 * 24 * 24)
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#define TCP_PAWS_MSL 60 /* Per-host timestamps are invalidated
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* after this time. It should be equal
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* (or greater than) TCP_TIMEWAIT_LEN
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* to provide reliability equal to one
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* provided by timewait state.
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*/
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#define TCP_PAWS_WINDOW 1 /* Replay window for per-host
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* timestamps. It must be less than
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* minimal timewait lifetime.
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*/
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/*
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* TCP option
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*/
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#define TCPOPT_NOP 1 /* Padding */
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#define TCPOPT_EOL 0 /* End of options */
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#define TCPOPT_MSS 2 /* Segment size negotiating */
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#define TCPOPT_WINDOW 3 /* Window scaling */
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#define TCPOPT_SACK_PERM 4 /* SACK Permitted */
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#define TCPOPT_SACK 5 /* SACK Block */
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#define TCPOPT_TIMESTAMP 8 /* Better RTT estimations/PAWS */
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#define TCPOPT_MD5SIG 19 /* MD5 Signature (RFC2385) */
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#define TCPOPT_EXP 254 /* Experimental */
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/* Magic number to be after the option value for sharing TCP
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* experimental options. See draft-ietf-tcpm-experimental-options-00.txt
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*/
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#define TCPOPT_FASTOPEN_MAGIC 0xF989
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/*
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* TCP option lengths
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*/
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#define TCPOLEN_MSS 4
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#define TCPOLEN_WINDOW 3
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#define TCPOLEN_SACK_PERM 2
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#define TCPOLEN_TIMESTAMP 10
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#define TCPOLEN_MD5SIG 18
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#define TCPOLEN_EXP_FASTOPEN_BASE 4
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/* But this is what stacks really send out. */
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#define TCPOLEN_TSTAMP_ALIGNED 12
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#define TCPOLEN_WSCALE_ALIGNED 4
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#define TCPOLEN_SACKPERM_ALIGNED 4
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#define TCPOLEN_SACK_BASE 2
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#define TCPOLEN_SACK_BASE_ALIGNED 4
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#define TCPOLEN_SACK_PERBLOCK 8
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#define TCPOLEN_MD5SIG_ALIGNED 20
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#define TCPOLEN_MSS_ALIGNED 4
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/* Flags in tp->nonagle */
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#define TCP_NAGLE_OFF 1 /* Nagle's algo is disabled */
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#define TCP_NAGLE_CORK 2 /* Socket is corked */
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#define TCP_NAGLE_PUSH 4 /* Cork is overridden for already queued data */
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/* TCP thin-stream limits */
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#define TCP_THIN_LINEAR_RETRIES 6 /* After 6 linear retries, do exp. backoff */
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/* TCP initial congestion window as per draft-hkchu-tcpm-initcwnd-01 */
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#define TCP_INIT_CWND 10
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/* Bit Flags for sysctl_tcp_fastopen */
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#define TFO_CLIENT_ENABLE 1
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#define TFO_SERVER_ENABLE 2
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#define TFO_CLIENT_NO_COOKIE 4 /* Data in SYN w/o cookie option */
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/* Process SYN data but skip cookie validation */
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#define TFO_SERVER_COOKIE_NOT_CHKED 0x100
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/* Accept SYN data w/o any cookie option */
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#define TFO_SERVER_COOKIE_NOT_REQD 0x200
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/* Force enable TFO on all listeners, i.e., not requiring the
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* TCP_FASTOPEN socket option. SOCKOPT1/2 determine how to set max_qlen.
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*/
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#define TFO_SERVER_WO_SOCKOPT1 0x400
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#define TFO_SERVER_WO_SOCKOPT2 0x800
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/* Always create TFO child sockets on a TFO listener even when
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* cookie/data not present. (For testing purpose!)
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*/
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#define TFO_SERVER_ALWAYS 0x1000
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extern struct inet_timewait_death_row tcp_death_row;
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/* sysctl variables for tcp */
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extern int sysctl_tcp_timestamps;
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extern int sysctl_tcp_window_scaling;
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extern int sysctl_tcp_sack;
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extern int sysctl_tcp_fin_timeout;
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extern int sysctl_tcp_keepalive_time;
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extern int sysctl_tcp_keepalive_probes;
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extern int sysctl_tcp_keepalive_intvl;
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extern int sysctl_tcp_syn_retries;
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extern int sysctl_tcp_synack_retries;
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extern int sysctl_tcp_retries1;
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extern int sysctl_tcp_retries2;
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extern int sysctl_tcp_orphan_retries;
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extern int sysctl_tcp_syncookies;
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extern int sysctl_tcp_fastopen;
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extern int sysctl_tcp_retrans_collapse;
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extern int sysctl_tcp_stdurg;
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extern int sysctl_tcp_rfc1337;
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extern int sysctl_tcp_abort_on_overflow;
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extern int sysctl_tcp_max_orphans;
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extern int sysctl_tcp_fack;
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extern int sysctl_tcp_reordering;
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extern int sysctl_tcp_dsack;
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extern int sysctl_tcp_wmem[3];
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extern int sysctl_tcp_rmem[3];
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extern int sysctl_tcp_app_win;
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extern int sysctl_tcp_adv_win_scale;
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extern int sysctl_tcp_tw_reuse;
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extern int sysctl_tcp_frto;
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extern int sysctl_tcp_low_latency;
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extern int sysctl_tcp_dma_copybreak;
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extern int sysctl_tcp_nometrics_save;
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extern int sysctl_tcp_moderate_rcvbuf;
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extern int sysctl_tcp_tso_win_divisor;
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extern int sysctl_tcp_mtu_probing;
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extern int sysctl_tcp_base_mss;
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extern int sysctl_tcp_workaround_signed_windows;
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extern int sysctl_tcp_slow_start_after_idle;
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extern int sysctl_tcp_max_ssthresh;
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extern int sysctl_tcp_thin_linear_timeouts;
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extern int sysctl_tcp_thin_dupack;
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extern int sysctl_tcp_early_retrans;
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extern int sysctl_tcp_limit_output_bytes;
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extern int sysctl_tcp_challenge_ack_limit;
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extern unsigned int sysctl_tcp_notsent_lowat;
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extern int sysctl_tcp_min_tso_segs;
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extern atomic_long_t tcp_memory_allocated;
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extern struct percpu_counter tcp_sockets_allocated;
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extern int tcp_memory_pressure;
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/*
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* The next routines deal with comparing 32 bit unsigned ints
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* and worry about wraparound (automatic with unsigned arithmetic).
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*/
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static inline bool before(__u32 seq1, __u32 seq2)
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{
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return (__s32)(seq1-seq2) < 0;
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}
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#define after(seq2, seq1) before(seq1, seq2)
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/* is s2<=s1<=s3 ? */
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static inline bool between(__u32 seq1, __u32 seq2, __u32 seq3)
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{
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return seq3 - seq2 >= seq1 - seq2;
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}
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static inline bool tcp_out_of_memory(struct sock *sk)
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{
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if (sk->sk_wmem_queued > SOCK_MIN_SNDBUF &&
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sk_memory_allocated(sk) > sk_prot_mem_limits(sk, 2))
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return true;
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return false;
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}
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static inline bool tcp_too_many_orphans(struct sock *sk, int shift)
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{
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struct percpu_counter *ocp = sk->sk_prot->orphan_count;
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int orphans = percpu_counter_read_positive(ocp);
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if (orphans << shift > sysctl_tcp_max_orphans) {
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orphans = percpu_counter_sum_positive(ocp);
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if (orphans << shift > sysctl_tcp_max_orphans)
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return true;
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}
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return false;
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}
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extern bool tcp_check_oom(struct sock *sk, int shift);
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/* syncookies: remember time of last synqueue overflow */
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static inline void tcp_synq_overflow(struct sock *sk)
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{
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tcp_sk(sk)->rx_opt.ts_recent_stamp = jiffies;
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}
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/* syncookies: no recent synqueue overflow on this listening socket? */
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static inline bool tcp_synq_no_recent_overflow(const struct sock *sk)
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{
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unsigned long last_overflow = tcp_sk(sk)->rx_opt.ts_recent_stamp;
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return time_after(jiffies, last_overflow + TCP_TIMEOUT_FALLBACK);
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}
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extern struct proto tcp_prot;
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#define TCP_INC_STATS(net, field) SNMP_INC_STATS((net)->mib.tcp_statistics, field)
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#define TCP_INC_STATS_BH(net, field) SNMP_INC_STATS_BH((net)->mib.tcp_statistics, field)
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#define TCP_DEC_STATS(net, field) SNMP_DEC_STATS((net)->mib.tcp_statistics, field)
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#define TCP_ADD_STATS_USER(net, field, val) SNMP_ADD_STATS_USER((net)->mib.tcp_statistics, field, val)
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#define TCP_ADD_STATS(net, field, val) SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val)
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extern void tcp_init_mem(struct net *net);
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extern void tcp_tasklet_init(void);
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extern void tcp_v4_err(struct sk_buff *skb, u32);
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extern void tcp_shutdown (struct sock *sk, int how);
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extern void tcp_v4_early_demux(struct sk_buff *skb);
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extern int tcp_v4_rcv(struct sk_buff *skb);
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extern int tcp_v4_tw_remember_stamp(struct inet_timewait_sock *tw);
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extern int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
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size_t size);
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extern int tcp_sendpage(struct sock *sk, struct page *page, int offset,
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size_t size, int flags);
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extern void tcp_release_cb(struct sock *sk);
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extern void tcp_wfree(struct sk_buff *skb);
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extern void tcp_write_timer_handler(struct sock *sk);
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extern void tcp_delack_timer_handler(struct sock *sk);
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extern int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg);
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extern int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb,
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const struct tcphdr *th, unsigned int len);
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extern void tcp_rcv_established(struct sock *sk, struct sk_buff *skb,
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const struct tcphdr *th, unsigned int len);
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extern void tcp_rcv_space_adjust(struct sock *sk);
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extern void tcp_cleanup_rbuf(struct sock *sk, int copied);
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extern int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp);
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extern void tcp_twsk_destructor(struct sock *sk);
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extern ssize_t tcp_splice_read(struct socket *sk, loff_t *ppos,
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struct pipe_inode_info *pipe, size_t len,
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unsigned int flags);
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static inline void tcp_dec_quickack_mode(struct sock *sk,
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const unsigned int pkts)
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{
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struct inet_connection_sock *icsk = inet_csk(sk);
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if (icsk->icsk_ack.quick) {
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if (pkts >= icsk->icsk_ack.quick) {
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icsk->icsk_ack.quick = 0;
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/* Leaving quickack mode we deflate ATO. */
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icsk->icsk_ack.ato = TCP_ATO_MIN;
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} else
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icsk->icsk_ack.quick -= pkts;
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}
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}
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#define TCP_ECN_OK 1
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#define TCP_ECN_QUEUE_CWR 2
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#define TCP_ECN_DEMAND_CWR 4
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#define TCP_ECN_SEEN 8
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enum tcp_tw_status {
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TCP_TW_SUCCESS = 0,
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TCP_TW_RST = 1,
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TCP_TW_ACK = 2,
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TCP_TW_SYN = 3
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};
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extern enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw,
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struct sk_buff *skb,
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const struct tcphdr *th);
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extern struct sock * tcp_check_req(struct sock *sk,struct sk_buff *skb,
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struct request_sock *req,
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struct request_sock **prev,
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bool fastopen);
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extern int tcp_child_process(struct sock *parent, struct sock *child,
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struct sk_buff *skb);
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extern void tcp_enter_loss(struct sock *sk, int how);
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extern void tcp_clear_retrans(struct tcp_sock *tp);
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extern void tcp_update_metrics(struct sock *sk);
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extern void tcp_init_metrics(struct sock *sk);
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extern void tcp_metrics_init(void);
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extern bool tcp_peer_is_proven(struct request_sock *req, struct dst_entry *dst, bool paws_check);
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extern bool tcp_remember_stamp(struct sock *sk);
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extern bool tcp_tw_remember_stamp(struct inet_timewait_sock *tw);
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extern void tcp_fetch_timewait_stamp(struct sock *sk, struct dst_entry *dst);
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extern void tcp_disable_fack(struct tcp_sock *tp);
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extern void tcp_close(struct sock *sk, long timeout);
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extern void tcp_init_sock(struct sock *sk);
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extern unsigned int tcp_poll(struct file * file, struct socket *sock,
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struct poll_table_struct *wait);
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extern int tcp_getsockopt(struct sock *sk, int level, int optname,
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char __user *optval, int __user *optlen);
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extern int tcp_setsockopt(struct sock *sk, int level, int optname,
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char __user *optval, unsigned int optlen);
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extern int compat_tcp_getsockopt(struct sock *sk, int level, int optname,
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char __user *optval, int __user *optlen);
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extern int compat_tcp_setsockopt(struct sock *sk, int level, int optname,
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char __user *optval, unsigned int optlen);
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extern void tcp_set_keepalive(struct sock *sk, int val);
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extern void tcp_syn_ack_timeout(struct sock *sk, struct request_sock *req);
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extern int tcp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
|
|
size_t len, int nonblock, int flags, int *addr_len);
|
|
extern void tcp_parse_options(const struct sk_buff *skb,
|
|
struct tcp_options_received *opt_rx,
|
|
int estab, struct tcp_fastopen_cookie *foc);
|
|
extern const u8 *tcp_parse_md5sig_option(const struct tcphdr *th);
|
|
|
|
/*
|
|
* TCP v4 functions exported for the inet6 API
|
|
*/
|
|
|
|
extern void tcp_v4_send_check(struct sock *sk, struct sk_buff *skb);
|
|
extern int tcp_v4_conn_request(struct sock *sk, struct sk_buff *skb);
|
|
extern struct sock * tcp_create_openreq_child(struct sock *sk,
|
|
struct request_sock *req,
|
|
struct sk_buff *skb);
|
|
extern struct sock * tcp_v4_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
|
|
struct request_sock *req,
|
|
struct dst_entry *dst);
|
|
extern int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb);
|
|
extern int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr,
|
|
int addr_len);
|
|
extern int tcp_connect(struct sock *sk);
|
|
extern struct sk_buff * tcp_make_synack(struct sock *sk, struct dst_entry *dst,
|
|
struct request_sock *req,
|
|
struct tcp_fastopen_cookie *foc);
|
|
extern int tcp_disconnect(struct sock *sk, int flags);
|
|
|
|
void tcp_connect_init(struct sock *sk);
|
|
void tcp_finish_connect(struct sock *sk, struct sk_buff *skb);
|
|
int tcp_send_rcvq(struct sock *sk, struct msghdr *msg, size_t size);
|
|
void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb);
|
|
|
|
/* From syncookies.c */
|
|
extern __u32 syncookie_secret[2][16-4+SHA_DIGEST_WORDS];
|
|
extern int __cookie_v4_check(const struct iphdr *iph, const struct tcphdr *th,
|
|
u32 cookie);
|
|
extern struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb,
|
|
struct ip_options *opt);
|
|
#ifdef CONFIG_SYN_COOKIES
|
|
extern u32 __cookie_v4_init_sequence(const struct iphdr *iph,
|
|
const struct tcphdr *th, u16 *mssp);
|
|
extern __u32 cookie_v4_init_sequence(struct sock *sk, struct sk_buff *skb,
|
|
__u16 *mss);
|
|
#else
|
|
static inline __u32 cookie_v4_init_sequence(struct sock *sk,
|
|
struct sk_buff *skb,
|
|
__u16 *mss)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
extern __u32 cookie_init_timestamp(struct request_sock *req);
|
|
extern bool cookie_check_timestamp(struct tcp_options_received *opt,
|
|
struct net *net, bool *ecn_ok);
|
|
|
|
/* From net/ipv6/syncookies.c */
|
|
extern int __cookie_v6_check(const struct ipv6hdr *iph, const struct tcphdr *th,
|
|
u32 cookie);
|
|
extern struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb);
|
|
#ifdef CONFIG_SYN_COOKIES
|
|
extern u32 __cookie_v6_init_sequence(const struct ipv6hdr *iph,
|
|
const struct tcphdr *th, u16 *mssp);
|
|
extern __u32 cookie_v6_init_sequence(struct sock *sk, const struct sk_buff *skb,
|
|
__u16 *mss);
|
|
#else
|
|
static inline __u32 cookie_v6_init_sequence(struct sock *sk,
|
|
struct sk_buff *skb,
|
|
__u16 *mss)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif
|
|
/* tcp_output.c */
|
|
|
|
extern void __tcp_push_pending_frames(struct sock *sk, unsigned int cur_mss,
|
|
int nonagle);
|
|
extern bool tcp_may_send_now(struct sock *sk);
|
|
extern int __tcp_retransmit_skb(struct sock *, struct sk_buff *);
|
|
extern int tcp_retransmit_skb(struct sock *, struct sk_buff *);
|
|
extern void tcp_retransmit_timer(struct sock *sk);
|
|
extern void tcp_xmit_retransmit_queue(struct sock *);
|
|
extern void tcp_simple_retransmit(struct sock *);
|
|
extern int tcp_trim_head(struct sock *, struct sk_buff *, u32);
|
|
extern int tcp_fragment(struct sock *, struct sk_buff *, u32, unsigned int);
|
|
|
|
extern void tcp_send_probe0(struct sock *);
|
|
extern void tcp_send_partial(struct sock *);
|
|
extern int tcp_write_wakeup(struct sock *);
|
|
extern void tcp_send_fin(struct sock *sk);
|
|
extern void tcp_send_active_reset(struct sock *sk, gfp_t priority);
|
|
extern int tcp_send_synack(struct sock *);
|
|
extern bool tcp_syn_flood_action(struct sock *sk,
|
|
const struct sk_buff *skb,
|
|
const char *proto);
|
|
extern void tcp_push_one(struct sock *, unsigned int mss_now);
|
|
extern void tcp_send_ack(struct sock *sk);
|
|
extern void tcp_send_delayed_ack(struct sock *sk);
|
|
extern void tcp_send_loss_probe(struct sock *sk);
|
|
extern bool tcp_schedule_loss_probe(struct sock *sk);
|
|
|
|
/* tcp_input.c */
|
|
extern void tcp_cwnd_application_limited(struct sock *sk);
|
|
extern void tcp_resume_early_retransmit(struct sock *sk);
|
|
extern void tcp_rearm_rto(struct sock *sk);
|
|
extern void tcp_reset(struct sock *sk);
|
|
|
|
/* tcp_timer.c */
|
|
extern void tcp_init_xmit_timers(struct sock *);
|
|
static inline void tcp_clear_xmit_timers(struct sock *sk)
|
|
{
|
|
inet_csk_clear_xmit_timers(sk);
|
|
}
|
|
|
|
extern unsigned int tcp_sync_mss(struct sock *sk, u32 pmtu);
|
|
extern unsigned int tcp_current_mss(struct sock *sk);
|
|
|
|
/* Bound MSS / TSO packet size with the half of the window */
|
|
static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize)
|
|
{
|
|
int cutoff;
|
|
|
|
/* When peer uses tiny windows, there is no use in packetizing
|
|
* to sub-MSS pieces for the sake of SWS or making sure there
|
|
* are enough packets in the pipe for fast recovery.
|
|
*
|
|
* On the other hand, for extremely large MSS devices, handling
|
|
* smaller than MSS windows in this way does make sense.
|
|
*/
|
|
if (tp->max_window >= 512)
|
|
cutoff = (tp->max_window >> 1);
|
|
else
|
|
cutoff = tp->max_window;
|
|
|
|
if (cutoff && pktsize > cutoff)
|
|
return max_t(int, cutoff, 68U - tp->tcp_header_len);
|
|
else
|
|
return pktsize;
|
|
}
|
|
|
|
/* tcp.c */
|
|
extern void tcp_get_info(const struct sock *, struct tcp_info *);
|
|
|
|
/* Read 'sendfile()'-style from a TCP socket */
|
|
typedef int (*sk_read_actor_t)(read_descriptor_t *, struct sk_buff *,
|
|
unsigned int, size_t);
|
|
extern int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
|
|
sk_read_actor_t recv_actor);
|
|
|
|
extern void tcp_initialize_rcv_mss(struct sock *sk);
|
|
|
|
extern int tcp_mtu_to_mss(struct sock *sk, int pmtu);
|
|
extern int tcp_mss_to_mtu(struct sock *sk, int mss);
|
|
extern void tcp_mtup_init(struct sock *sk);
|
|
extern void tcp_init_buffer_space(struct sock *sk);
|
|
|
|
static inline void tcp_bound_rto(const struct sock *sk)
|
|
{
|
|
if (inet_csk(sk)->icsk_rto > TCP_RTO_MAX)
|
|
inet_csk(sk)->icsk_rto = TCP_RTO_MAX;
|
|
}
|
|
|
|
static inline u32 __tcp_set_rto(const struct tcp_sock *tp)
|
|
{
|
|
return (tp->srtt >> 3) + tp->rttvar;
|
|
}
|
|
|
|
extern void tcp_set_rto(struct sock *sk);
|
|
|
|
static inline void __tcp_fast_path_on(struct tcp_sock *tp, u32 snd_wnd)
|
|
{
|
|
tp->pred_flags = htonl((tp->tcp_header_len << 26) |
|
|
ntohl(TCP_FLAG_ACK) |
|
|
snd_wnd);
|
|
}
|
|
|
|
static inline void tcp_fast_path_on(struct tcp_sock *tp)
|
|
{
|
|
__tcp_fast_path_on(tp, tp->snd_wnd >> tp->rx_opt.snd_wscale);
|
|
}
|
|
|
|
static inline void tcp_fast_path_check(struct sock *sk)
|
|
{
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
if (skb_queue_empty(&tp->out_of_order_queue) &&
|
|
tp->rcv_wnd &&
|
|
atomic_read(&sk->sk_rmem_alloc) < sk->sk_rcvbuf &&
|
|
!tp->urg_data)
|
|
tcp_fast_path_on(tp);
|
|
}
|
|
|
|
/* Compute the actual rto_min value */
|
|
static inline u32 tcp_rto_min(struct sock *sk)
|
|
{
|
|
const struct dst_entry *dst = __sk_dst_get(sk);
|
|
u32 rto_min = TCP_RTO_MIN;
|
|
|
|
if (dst && dst_metric_locked(dst, RTAX_RTO_MIN))
|
|
rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN);
|
|
return rto_min;
|
|
}
|
|
|
|
/* Compute the actual receive window we are currently advertising.
|
|
* Rcv_nxt can be after the window if our peer push more data
|
|
* than the offered window.
|
|
*/
|
|
static inline u32 tcp_receive_window(const struct tcp_sock *tp)
|
|
{
|
|
s32 win = tp->rcv_wup + tp->rcv_wnd - tp->rcv_nxt;
|
|
|
|
if (win < 0)
|
|
win = 0;
|
|
return (u32) win;
|
|
}
|
|
|
|
/* Choose a new window, without checks for shrinking, and without
|
|
* scaling applied to the result. The caller does these things
|
|
* if necessary. This is a "raw" window selection.
|
|
*/
|
|
extern u32 __tcp_select_window(struct sock *sk);
|
|
|
|
void tcp_send_window_probe(struct sock *sk);
|
|
|
|
/* TCP timestamps are only 32-bits, this causes a slight
|
|
* complication on 64-bit systems since we store a snapshot
|
|
* of jiffies in the buffer control blocks below. We decided
|
|
* to use only the low 32-bits of jiffies and hide the ugly
|
|
* casts with the following macro.
|
|
*/
|
|
#define tcp_time_stamp ((__u32)(jiffies))
|
|
|
|
#define tcp_flag_byte(th) (((u_int8_t *)th)[13])
|
|
|
|
#define TCPHDR_FIN 0x01
|
|
#define TCPHDR_SYN 0x02
|
|
#define TCPHDR_RST 0x04
|
|
#define TCPHDR_PSH 0x08
|
|
#define TCPHDR_ACK 0x10
|
|
#define TCPHDR_URG 0x20
|
|
#define TCPHDR_ECE 0x40
|
|
#define TCPHDR_CWR 0x80
|
|
|
|
/* This is what the send packet queuing engine uses to pass
|
|
* TCP per-packet control information to the transmission code.
|
|
* We also store the host-order sequence numbers in here too.
|
|
* This is 44 bytes if IPV6 is enabled.
|
|
* If this grows please adjust skbuff.h:skbuff->cb[xxx] size appropriately.
|
|
*/
|
|
struct tcp_skb_cb {
|
|
union {
|
|
struct inet_skb_parm h4;
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
struct inet6_skb_parm h6;
|
|
#endif
|
|
} header; /* For incoming frames */
|
|
__u32 seq; /* Starting sequence number */
|
|
__u32 end_seq; /* SEQ + FIN + SYN + datalen */
|
|
__u32 when; /* used to compute rtt's */
|
|
__u8 tcp_flags; /* TCP header flags. (tcp[13]) */
|
|
|
|
__u8 sacked; /* State flags for SACK/FACK. */
|
|
#define TCPCB_SACKED_ACKED 0x01 /* SKB ACK'd by a SACK block */
|
|
#define TCPCB_SACKED_RETRANS 0x02 /* SKB retransmitted */
|
|
#define TCPCB_LOST 0x04 /* SKB is lost */
|
|
#define TCPCB_TAGBITS 0x07 /* All tag bits */
|
|
#define TCPCB_EVER_RETRANS 0x80 /* Ever retransmitted frame */
|
|
#define TCPCB_RETRANS (TCPCB_SACKED_RETRANS|TCPCB_EVER_RETRANS)
|
|
|
|
__u8 ip_dsfield; /* IPv4 tos or IPv6 dsfield */
|
|
/* 1 byte hole */
|
|
__u32 ack_seq; /* Sequence number ACK'd */
|
|
};
|
|
|
|
#define TCP_SKB_CB(__skb) ((struct tcp_skb_cb *)&((__skb)->cb[0]))
|
|
|
|
/* RFC3168 : 6.1.1 SYN packets must not have ECT/ECN bits set
|
|
*
|
|
* If we receive a SYN packet with these bits set, it means a network is
|
|
* playing bad games with TOS bits. In order to avoid possible false congestion
|
|
* notifications, we disable TCP ECN negociation.
|
|
*/
|
|
static inline void
|
|
TCP_ECN_create_request(struct request_sock *req, const struct sk_buff *skb,
|
|
struct net *net)
|
|
{
|
|
const struct tcphdr *th = tcp_hdr(skb);
|
|
|
|
if (net->ipv4.sysctl_tcp_ecn && th->ece && th->cwr &&
|
|
INET_ECN_is_not_ect(TCP_SKB_CB(skb)->ip_dsfield))
|
|
inet_rsk(req)->ecn_ok = 1;
|
|
}
|
|
|
|
/* Due to TSO, an SKB can be composed of multiple actual
|
|
* packets. To keep these tracked properly, we use this.
|
|
*/
|
|
static inline int tcp_skb_pcount(const struct sk_buff *skb)
|
|
{
|
|
return skb_shinfo(skb)->gso_segs;
|
|
}
|
|
|
|
/* This is valid iff tcp_skb_pcount() > 1. */
|
|
static inline int tcp_skb_mss(const struct sk_buff *skb)
|
|
{
|
|
return skb_shinfo(skb)->gso_size;
|
|
}
|
|
|
|
/* Events passed to congestion control interface */
|
|
enum tcp_ca_event {
|
|
CA_EVENT_TX_START, /* first transmit when no packets in flight */
|
|
CA_EVENT_CWND_RESTART, /* congestion window restart */
|
|
CA_EVENT_COMPLETE_CWR, /* end of congestion recovery */
|
|
CA_EVENT_LOSS, /* loss timeout */
|
|
CA_EVENT_FAST_ACK, /* in sequence ack */
|
|
CA_EVENT_SLOW_ACK, /* other ack */
|
|
};
|
|
|
|
/*
|
|
* Interface for adding new TCP congestion control handlers
|
|
*/
|
|
#define TCP_CA_NAME_MAX 16
|
|
#define TCP_CA_MAX 128
|
|
#define TCP_CA_BUF_MAX (TCP_CA_NAME_MAX*TCP_CA_MAX)
|
|
|
|
#define TCP_CONG_NON_RESTRICTED 0x1
|
|
#define TCP_CONG_RTT_STAMP 0x2
|
|
|
|
struct tcp_congestion_ops {
|
|
struct list_head list;
|
|
unsigned long flags;
|
|
|
|
/* initialize private data (optional) */
|
|
void (*init)(struct sock *sk);
|
|
/* cleanup private data (optional) */
|
|
void (*release)(struct sock *sk);
|
|
|
|
/* return slow start threshold (required) */
|
|
u32 (*ssthresh)(struct sock *sk);
|
|
/* lower bound for congestion window (optional) */
|
|
u32 (*min_cwnd)(const struct sock *sk);
|
|
/* do new cwnd calculation (required) */
|
|
void (*cong_avoid)(struct sock *sk, u32 ack, u32 in_flight);
|
|
/* call before changing ca_state (optional) */
|
|
void (*set_state)(struct sock *sk, u8 new_state);
|
|
/* call when cwnd event occurs (optional) */
|
|
void (*cwnd_event)(struct sock *sk, enum tcp_ca_event ev);
|
|
/* new value of cwnd after loss (optional) */
|
|
u32 (*undo_cwnd)(struct sock *sk);
|
|
/* hook for packet ack accounting (optional) */
|
|
void (*pkts_acked)(struct sock *sk, u32 num_acked, s32 rtt_us);
|
|
/* get info for inet_diag (optional) */
|
|
void (*get_info)(struct sock *sk, u32 ext, struct sk_buff *skb);
|
|
|
|
char name[TCP_CA_NAME_MAX];
|
|
struct module *owner;
|
|
};
|
|
|
|
extern int tcp_register_congestion_control(struct tcp_congestion_ops *type);
|
|
extern void tcp_unregister_congestion_control(struct tcp_congestion_ops *type);
|
|
|
|
extern void tcp_init_congestion_control(struct sock *sk);
|
|
extern void tcp_cleanup_congestion_control(struct sock *sk);
|
|
extern int tcp_set_default_congestion_control(const char *name);
|
|
extern void tcp_get_default_congestion_control(char *name);
|
|
extern void tcp_get_available_congestion_control(char *buf, size_t len);
|
|
extern void tcp_get_allowed_congestion_control(char *buf, size_t len);
|
|
extern int tcp_set_allowed_congestion_control(char *allowed);
|
|
extern int tcp_set_congestion_control(struct sock *sk, const char *name);
|
|
extern void tcp_slow_start(struct tcp_sock *tp);
|
|
extern void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w);
|
|
|
|
extern struct tcp_congestion_ops tcp_init_congestion_ops;
|
|
extern u32 tcp_reno_ssthresh(struct sock *sk);
|
|
extern void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight);
|
|
extern u32 tcp_reno_min_cwnd(const struct sock *sk);
|
|
extern struct tcp_congestion_ops tcp_reno;
|
|
|
|
static inline void tcp_set_ca_state(struct sock *sk, const u8 ca_state)
|
|
{
|
|
struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (icsk->icsk_ca_ops->set_state)
|
|
icsk->icsk_ca_ops->set_state(sk, ca_state);
|
|
icsk->icsk_ca_state = ca_state;
|
|
}
|
|
|
|
static inline void tcp_ca_event(struct sock *sk, const enum tcp_ca_event event)
|
|
{
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (icsk->icsk_ca_ops->cwnd_event)
|
|
icsk->icsk_ca_ops->cwnd_event(sk, event);
|
|
}
|
|
|
|
/* These functions determine how the current flow behaves in respect of SACK
|
|
* handling. SACK is negotiated with the peer, and therefore it can vary
|
|
* between different flows.
|
|
*
|
|
* tcp_is_sack - SACK enabled
|
|
* tcp_is_reno - No SACK
|
|
* tcp_is_fack - FACK enabled, implies SACK enabled
|
|
*/
|
|
static inline int tcp_is_sack(const struct tcp_sock *tp)
|
|
{
|
|
return tp->rx_opt.sack_ok;
|
|
}
|
|
|
|
static inline bool tcp_is_reno(const struct tcp_sock *tp)
|
|
{
|
|
return !tcp_is_sack(tp);
|
|
}
|
|
|
|
static inline bool tcp_is_fack(const struct tcp_sock *tp)
|
|
{
|
|
return tp->rx_opt.sack_ok & TCP_FACK_ENABLED;
|
|
}
|
|
|
|
static inline void tcp_enable_fack(struct tcp_sock *tp)
|
|
{
|
|
tp->rx_opt.sack_ok |= TCP_FACK_ENABLED;
|
|
}
|
|
|
|
/* TCP early-retransmit (ER) is similar to but more conservative than
|
|
* the thin-dupack feature. Enable ER only if thin-dupack is disabled.
|
|
*/
|
|
static inline void tcp_enable_early_retrans(struct tcp_sock *tp)
|
|
{
|
|
tp->do_early_retrans = sysctl_tcp_early_retrans &&
|
|
sysctl_tcp_early_retrans < 4 && !sysctl_tcp_thin_dupack &&
|
|
sysctl_tcp_reordering == 3;
|
|
}
|
|
|
|
static inline void tcp_disable_early_retrans(struct tcp_sock *tp)
|
|
{
|
|
tp->do_early_retrans = 0;
|
|
}
|
|
|
|
static inline unsigned int tcp_left_out(const struct tcp_sock *tp)
|
|
{
|
|
return tp->sacked_out + tp->lost_out;
|
|
}
|
|
|
|
/* This determines how many packets are "in the network" to the best
|
|
* of our knowledge. In many cases it is conservative, but where
|
|
* detailed information is available from the receiver (via SACK
|
|
* blocks etc.) we can make more aggressive calculations.
|
|
*
|
|
* Use this for decisions involving congestion control, use just
|
|
* tp->packets_out to determine if the send queue is empty or not.
|
|
*
|
|
* Read this equation as:
|
|
*
|
|
* "Packets sent once on transmission queue" MINUS
|
|
* "Packets left network, but not honestly ACKed yet" PLUS
|
|
* "Packets fast retransmitted"
|
|
*/
|
|
static inline unsigned int tcp_packets_in_flight(const struct tcp_sock *tp)
|
|
{
|
|
return tp->packets_out - tcp_left_out(tp) + tp->retrans_out;
|
|
}
|
|
|
|
#define TCP_INFINITE_SSTHRESH 0x7fffffff
|
|
|
|
static inline bool tcp_in_initial_slowstart(const struct tcp_sock *tp)
|
|
{
|
|
return tp->snd_ssthresh >= TCP_INFINITE_SSTHRESH;
|
|
}
|
|
|
|
static inline bool tcp_in_cwnd_reduction(const struct sock *sk)
|
|
{
|
|
return (TCPF_CA_CWR | TCPF_CA_Recovery) &
|
|
(1 << inet_csk(sk)->icsk_ca_state);
|
|
}
|
|
|
|
/* If cwnd > ssthresh, we may raise ssthresh to be half-way to cwnd.
|
|
* The exception is cwnd reduction phase, when cwnd is decreasing towards
|
|
* ssthresh.
|
|
*/
|
|
static inline __u32 tcp_current_ssthresh(const struct sock *sk)
|
|
{
|
|
const struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
if (tcp_in_cwnd_reduction(sk))
|
|
return tp->snd_ssthresh;
|
|
else
|
|
return max(tp->snd_ssthresh,
|
|
((tp->snd_cwnd >> 1) +
|
|
(tp->snd_cwnd >> 2)));
|
|
}
|
|
|
|
/* Use define here intentionally to get WARN_ON location shown at the caller */
|
|
#define tcp_verify_left_out(tp) WARN_ON(tcp_left_out(tp) > tp->packets_out)
|
|
|
|
extern void tcp_enter_cwr(struct sock *sk, const int set_ssthresh);
|
|
extern __u32 tcp_init_cwnd(const struct tcp_sock *tp, const struct dst_entry *dst);
|
|
|
|
/* The maximum number of MSS of available cwnd for which TSO defers
|
|
* sending if not using sysctl_tcp_tso_win_divisor.
|
|
*/
|
|
static inline __u32 tcp_max_tso_deferred_mss(const struct tcp_sock *tp)
|
|
{
|
|
return 3;
|
|
}
|
|
|
|
/* Slow start with delack produces 3 packets of burst, so that
|
|
* it is safe "de facto". This will be the default - same as
|
|
* the default reordering threshold - but if reordering increases,
|
|
* we must be able to allow cwnd to burst at least this much in order
|
|
* to not pull it back when holes are filled.
|
|
*/
|
|
static __inline__ __u32 tcp_max_burst(const struct tcp_sock *tp)
|
|
{
|
|
return tp->reordering;
|
|
}
|
|
|
|
/* Returns end sequence number of the receiver's advertised window */
|
|
static inline u32 tcp_wnd_end(const struct tcp_sock *tp)
|
|
{
|
|
return tp->snd_una + tp->snd_wnd;
|
|
}
|
|
extern bool tcp_is_cwnd_limited(const struct sock *sk, u32 in_flight);
|
|
|
|
static inline void tcp_minshall_update(struct tcp_sock *tp, unsigned int mss,
|
|
const struct sk_buff *skb)
|
|
{
|
|
if (skb->len < mss)
|
|
tp->snd_sml = TCP_SKB_CB(skb)->end_seq;
|
|
}
|
|
|
|
static inline void tcp_check_probe_timer(struct sock *sk)
|
|
{
|
|
const struct tcp_sock *tp = tcp_sk(sk);
|
|
const struct inet_connection_sock *icsk = inet_csk(sk);
|
|
|
|
if (!tp->packets_out && !icsk->icsk_pending)
|
|
inet_csk_reset_xmit_timer(sk, ICSK_TIME_PROBE0,
|
|
icsk->icsk_rto, TCP_RTO_MAX);
|
|
}
|
|
|
|
static inline void tcp_init_wl(struct tcp_sock *tp, u32 seq)
|
|
{
|
|
tp->snd_wl1 = seq;
|
|
}
|
|
|
|
static inline void tcp_update_wl(struct tcp_sock *tp, u32 seq)
|
|
{
|
|
tp->snd_wl1 = seq;
|
|
}
|
|
|
|
/*
|
|
* Calculate(/check) TCP checksum
|
|
*/
|
|
static inline __sum16 tcp_v4_check(int len, __be32 saddr,
|
|
__be32 daddr, __wsum base)
|
|
{
|
|
return csum_tcpudp_magic(saddr,daddr,len,IPPROTO_TCP,base);
|
|
}
|
|
|
|
static inline __sum16 __tcp_checksum_complete(struct sk_buff *skb)
|
|
{
|
|
return __skb_checksum_complete(skb);
|
|
}
|
|
|
|
static inline bool tcp_checksum_complete(struct sk_buff *skb)
|
|
{
|
|
return !skb_csum_unnecessary(skb) &&
|
|
__tcp_checksum_complete(skb);
|
|
}
|
|
|
|
/* Prequeue for VJ style copy to user, combined with checksumming. */
|
|
|
|
static inline void tcp_prequeue_init(struct tcp_sock *tp)
|
|
{
|
|
tp->ucopy.task = NULL;
|
|
tp->ucopy.len = 0;
|
|
tp->ucopy.memory = 0;
|
|
skb_queue_head_init(&tp->ucopy.prequeue);
|
|
#ifdef CONFIG_NET_DMA
|
|
tp->ucopy.dma_chan = NULL;
|
|
tp->ucopy.wakeup = 0;
|
|
tp->ucopy.pinned_list = NULL;
|
|
tp->ucopy.dma_cookie = 0;
|
|
#endif
|
|
}
|
|
|
|
extern bool tcp_prequeue(struct sock *sk, struct sk_buff *skb);
|
|
|
|
#undef STATE_TRACE
|
|
|
|
#ifdef STATE_TRACE
|
|
static const char *statename[]={
|
|
"Unused","Established","Syn Sent","Syn Recv",
|
|
"Fin Wait 1","Fin Wait 2","Time Wait", "Close",
|
|
"Close Wait","Last ACK","Listen","Closing"
|
|
};
|
|
#endif
|
|
extern void tcp_set_state(struct sock *sk, int state);
|
|
|
|
extern void tcp_done(struct sock *sk);
|
|
|
|
static inline void tcp_sack_reset(struct tcp_options_received *rx_opt)
|
|
{
|
|
rx_opt->dsack = 0;
|
|
rx_opt->num_sacks = 0;
|
|
}
|
|
|
|
extern u32 tcp_default_init_rwnd(u32 mss);
|
|
|
|
/* Determine a window scaling and initial window to offer. */
|
|
extern void tcp_select_initial_window(int __space, __u32 mss,
|
|
__u32 *rcv_wnd, __u32 *window_clamp,
|
|
int wscale_ok, __u8 *rcv_wscale,
|
|
__u32 init_rcv_wnd);
|
|
|
|
static inline int tcp_win_from_space(int space)
|
|
{
|
|
return sysctl_tcp_adv_win_scale<=0 ?
|
|
(space>>(-sysctl_tcp_adv_win_scale)) :
|
|
space - (space>>sysctl_tcp_adv_win_scale);
|
|
}
|
|
|
|
/* Note: caller must be prepared to deal with negative returns */
|
|
static inline int tcp_space(const struct sock *sk)
|
|
{
|
|
return tcp_win_from_space(sk->sk_rcvbuf -
|
|
atomic_read(&sk->sk_rmem_alloc));
|
|
}
|
|
|
|
static inline int tcp_full_space(const struct sock *sk)
|
|
{
|
|
return tcp_win_from_space(sk->sk_rcvbuf);
|
|
}
|
|
|
|
static inline void tcp_openreq_init(struct request_sock *req,
|
|
struct tcp_options_received *rx_opt,
|
|
struct sk_buff *skb)
|
|
{
|
|
struct inet_request_sock *ireq = inet_rsk(req);
|
|
|
|
req->rcv_wnd = 0; /* So that tcp_send_synack() knows! */
|
|
req->cookie_ts = 0;
|
|
tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
|
|
tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->seq + 1;
|
|
tcp_rsk(req)->snt_synack = 0;
|
|
req->mss = rx_opt->mss_clamp;
|
|
req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
|
|
ireq->tstamp_ok = rx_opt->tstamp_ok;
|
|
ireq->sack_ok = rx_opt->sack_ok;
|
|
ireq->snd_wscale = rx_opt->snd_wscale;
|
|
ireq->wscale_ok = rx_opt->wscale_ok;
|
|
ireq->acked = 0;
|
|
ireq->ecn_ok = 0;
|
|
ireq->rmt_port = tcp_hdr(skb)->source;
|
|
ireq->loc_port = tcp_hdr(skb)->dest;
|
|
}
|
|
|
|
extern void tcp_enter_memory_pressure(struct sock *sk);
|
|
|
|
static inline int keepalive_intvl_when(const struct tcp_sock *tp)
|
|
{
|
|
return tp->keepalive_intvl ? : sysctl_tcp_keepalive_intvl;
|
|
}
|
|
|
|
static inline int keepalive_time_when(const struct tcp_sock *tp)
|
|
{
|
|
return tp->keepalive_time ? : sysctl_tcp_keepalive_time;
|
|
}
|
|
|
|
static inline int keepalive_probes(const struct tcp_sock *tp)
|
|
{
|
|
return tp->keepalive_probes ? : sysctl_tcp_keepalive_probes;
|
|
}
|
|
|
|
static inline u32 keepalive_time_elapsed(const struct tcp_sock *tp)
|
|
{
|
|
const struct inet_connection_sock *icsk = &tp->inet_conn;
|
|
|
|
return min_t(u32, tcp_time_stamp - icsk->icsk_ack.lrcvtime,
|
|
tcp_time_stamp - tp->rcv_tstamp);
|
|
}
|
|
|
|
static inline int tcp_fin_time(const struct sock *sk)
|
|
{
|
|
int fin_timeout = tcp_sk(sk)->linger2 ? : sysctl_tcp_fin_timeout;
|
|
const int rto = inet_csk(sk)->icsk_rto;
|
|
|
|
if (fin_timeout < (rto << 2) - (rto >> 1))
|
|
fin_timeout = (rto << 2) - (rto >> 1);
|
|
|
|
return fin_timeout;
|
|
}
|
|
|
|
static inline bool tcp_paws_check(const struct tcp_options_received *rx_opt,
|
|
int paws_win)
|
|
{
|
|
if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win)
|
|
return true;
|
|
if (unlikely(get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_24DAYS))
|
|
return true;
|
|
/*
|
|
* Some OSes send SYN and SYNACK messages with tsval=0 tsecr=0,
|
|
* then following tcp messages have valid values. Ignore 0 value,
|
|
* or else 'negative' tsval might forbid us to accept their packets.
|
|
*/
|
|
if (!rx_opt->ts_recent)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
static inline bool tcp_paws_reject(const struct tcp_options_received *rx_opt,
|
|
int rst)
|
|
{
|
|
if (tcp_paws_check(rx_opt, 0))
|
|
return false;
|
|
|
|
/* RST segments are not recommended to carry timestamp,
|
|
and, if they do, it is recommended to ignore PAWS because
|
|
"their cleanup function should take precedence over timestamps."
|
|
Certainly, it is mistake. It is necessary to understand the reasons
|
|
of this constraint to relax it: if peer reboots, clock may go
|
|
out-of-sync and half-open connections will not be reset.
|
|
Actually, the problem would be not existing if all
|
|
the implementations followed draft about maintaining clock
|
|
via reboots. Linux-2.2 DOES NOT!
|
|
|
|
However, we can relax time bounds for RST segments to MSL.
|
|
*/
|
|
if (rst && get_seconds() >= rx_opt->ts_recent_stamp + TCP_PAWS_MSL)
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static inline void tcp_mib_init(struct net *net)
|
|
{
|
|
/* See RFC 2012 */
|
|
TCP_ADD_STATS_USER(net, TCP_MIB_RTOALGORITHM, 1);
|
|
TCP_ADD_STATS_USER(net, TCP_MIB_RTOMIN, TCP_RTO_MIN*1000/HZ);
|
|
TCP_ADD_STATS_USER(net, TCP_MIB_RTOMAX, TCP_RTO_MAX*1000/HZ);
|
|
TCP_ADD_STATS_USER(net, TCP_MIB_MAXCONN, -1);
|
|
}
|
|
|
|
/* from STCP */
|
|
static inline void tcp_clear_retrans_hints_partial(struct tcp_sock *tp)
|
|
{
|
|
tp->lost_skb_hint = NULL;
|
|
}
|
|
|
|
static inline void tcp_clear_all_retrans_hints(struct tcp_sock *tp)
|
|
{
|
|
tcp_clear_retrans_hints_partial(tp);
|
|
tp->retransmit_skb_hint = NULL;
|
|
}
|
|
|
|
/* MD5 Signature */
|
|
struct crypto_hash;
|
|
|
|
union tcp_md5_addr {
|
|
struct in_addr a4;
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
struct in6_addr a6;
|
|
#endif
|
|
};
|
|
|
|
/* - key database */
|
|
struct tcp_md5sig_key {
|
|
struct hlist_node node;
|
|
u8 keylen;
|
|
u8 family; /* AF_INET or AF_INET6 */
|
|
union tcp_md5_addr addr;
|
|
u8 key[TCP_MD5SIG_MAXKEYLEN];
|
|
struct rcu_head rcu;
|
|
};
|
|
|
|
/* - sock block */
|
|
struct tcp_md5sig_info {
|
|
struct hlist_head head;
|
|
struct rcu_head rcu;
|
|
};
|
|
|
|
/* - pseudo header */
|
|
struct tcp4_pseudohdr {
|
|
__be32 saddr;
|
|
__be32 daddr;
|
|
__u8 pad;
|
|
__u8 protocol;
|
|
__be16 len;
|
|
};
|
|
|
|
struct tcp6_pseudohdr {
|
|
struct in6_addr saddr;
|
|
struct in6_addr daddr;
|
|
__be32 len;
|
|
__be32 protocol; /* including padding */
|
|
};
|
|
|
|
union tcp_md5sum_block {
|
|
struct tcp4_pseudohdr ip4;
|
|
#if IS_ENABLED(CONFIG_IPV6)
|
|
struct tcp6_pseudohdr ip6;
|
|
#endif
|
|
};
|
|
|
|
/* - pool: digest algorithm, hash description and scratch buffer */
|
|
struct tcp_md5sig_pool {
|
|
struct hash_desc md5_desc;
|
|
union tcp_md5sum_block md5_blk;
|
|
};
|
|
|
|
/* - functions */
|
|
extern int tcp_v4_md5_hash_skb(char *md5_hash, struct tcp_md5sig_key *key,
|
|
const struct sock *sk,
|
|
const struct request_sock *req,
|
|
const struct sk_buff *skb);
|
|
extern int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
|
|
int family, const u8 *newkey,
|
|
u8 newkeylen, gfp_t gfp);
|
|
extern int tcp_md5_do_del(struct sock *sk, const union tcp_md5_addr *addr,
|
|
int family);
|
|
extern struct tcp_md5sig_key *tcp_v4_md5_lookup(struct sock *sk,
|
|
struct sock *addr_sk);
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
extern struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk,
|
|
const union tcp_md5_addr *addr, int family);
|
|
#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key)
|
|
#else
|
|
static inline struct tcp_md5sig_key *tcp_md5_do_lookup(struct sock *sk,
|
|
const union tcp_md5_addr *addr,
|
|
int family)
|
|
{
|
|
return NULL;
|
|
}
|
|
#define tcp_twsk_md5_key(twsk) NULL
|
|
#endif
|
|
|
|
extern bool tcp_alloc_md5sig_pool(void);
|
|
|
|
extern struct tcp_md5sig_pool *tcp_get_md5sig_pool(void);
|
|
static inline void tcp_put_md5sig_pool(void)
|
|
{
|
|
local_bh_enable();
|
|
}
|
|
|
|
extern int tcp_md5_hash_header(struct tcp_md5sig_pool *, const struct tcphdr *);
|
|
extern int tcp_md5_hash_skb_data(struct tcp_md5sig_pool *, const struct sk_buff *,
|
|
unsigned int header_len);
|
|
extern int tcp_md5_hash_key(struct tcp_md5sig_pool *hp,
|
|
const struct tcp_md5sig_key *key);
|
|
|
|
/* From tcp_fastopen.c */
|
|
extern void tcp_fastopen_cache_get(struct sock *sk, u16 *mss,
|
|
struct tcp_fastopen_cookie *cookie,
|
|
int *syn_loss, unsigned long *last_syn_loss);
|
|
extern void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
|
|
struct tcp_fastopen_cookie *cookie,
|
|
bool syn_lost);
|
|
struct tcp_fastopen_request {
|
|
/* Fast Open cookie. Size 0 means a cookie request */
|
|
struct tcp_fastopen_cookie cookie;
|
|
struct msghdr *data; /* data in MSG_FASTOPEN */
|
|
u16 copied; /* queued in tcp_connect() */
|
|
};
|
|
void tcp_free_fastopen_req(struct tcp_sock *tp);
|
|
|
|
extern struct tcp_fastopen_context __rcu *tcp_fastopen_ctx;
|
|
int tcp_fastopen_reset_cipher(void *key, unsigned int len);
|
|
extern void tcp_fastopen_cookie_gen(__be32 src, __be32 dst,
|
|
struct tcp_fastopen_cookie *foc);
|
|
|
|
#define TCP_FASTOPEN_KEY_LENGTH 16
|
|
|
|
/* Fastopen key context */
|
|
struct tcp_fastopen_context {
|
|
struct crypto_cipher *tfm;
|
|
__u8 key[TCP_FASTOPEN_KEY_LENGTH];
|
|
struct rcu_head rcu;
|
|
};
|
|
|
|
/* write queue abstraction */
|
|
static inline void tcp_write_queue_purge(struct sock *sk)
|
|
{
|
|
struct sk_buff *skb;
|
|
|
|
while ((skb = __skb_dequeue(&sk->sk_write_queue)) != NULL)
|
|
sk_wmem_free_skb(sk, skb);
|
|
sk_mem_reclaim(sk);
|
|
tcp_clear_all_retrans_hints(tcp_sk(sk));
|
|
}
|
|
|
|
static inline struct sk_buff *tcp_write_queue_head(const struct sock *sk)
|
|
{
|
|
return skb_peek(&sk->sk_write_queue);
|
|
}
|
|
|
|
static inline struct sk_buff *tcp_write_queue_tail(const struct sock *sk)
|
|
{
|
|
return skb_peek_tail(&sk->sk_write_queue);
|
|
}
|
|
|
|
static inline struct sk_buff *tcp_write_queue_next(const struct sock *sk,
|
|
const struct sk_buff *skb)
|
|
{
|
|
return skb_queue_next(&sk->sk_write_queue, skb);
|
|
}
|
|
|
|
static inline struct sk_buff *tcp_write_queue_prev(const struct sock *sk,
|
|
const struct sk_buff *skb)
|
|
{
|
|
return skb_queue_prev(&sk->sk_write_queue, skb);
|
|
}
|
|
|
|
#define tcp_for_write_queue(skb, sk) \
|
|
skb_queue_walk(&(sk)->sk_write_queue, skb)
|
|
|
|
#define tcp_for_write_queue_from(skb, sk) \
|
|
skb_queue_walk_from(&(sk)->sk_write_queue, skb)
|
|
|
|
#define tcp_for_write_queue_from_safe(skb, tmp, sk) \
|
|
skb_queue_walk_from_safe(&(sk)->sk_write_queue, skb, tmp)
|
|
|
|
static inline struct sk_buff *tcp_send_head(const struct sock *sk)
|
|
{
|
|
return sk->sk_send_head;
|
|
}
|
|
|
|
static inline bool tcp_skb_is_last(const struct sock *sk,
|
|
const struct sk_buff *skb)
|
|
{
|
|
return skb_queue_is_last(&sk->sk_write_queue, skb);
|
|
}
|
|
|
|
static inline void tcp_advance_send_head(struct sock *sk, const struct sk_buff *skb)
|
|
{
|
|
if (tcp_skb_is_last(sk, skb))
|
|
sk->sk_send_head = NULL;
|
|
else
|
|
sk->sk_send_head = tcp_write_queue_next(sk, skb);
|
|
}
|
|
|
|
static inline void tcp_check_send_head(struct sock *sk, struct sk_buff *skb_unlinked)
|
|
{
|
|
if (sk->sk_send_head == skb_unlinked)
|
|
sk->sk_send_head = NULL;
|
|
}
|
|
|
|
static inline void tcp_init_send_head(struct sock *sk)
|
|
{
|
|
sk->sk_send_head = NULL;
|
|
}
|
|
|
|
static inline void __tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
__skb_queue_tail(&sk->sk_write_queue, skb);
|
|
}
|
|
|
|
static inline void tcp_add_write_queue_tail(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
__tcp_add_write_queue_tail(sk, skb);
|
|
|
|
/* Queue it, remembering where we must start sending. */
|
|
if (sk->sk_send_head == NULL) {
|
|
sk->sk_send_head = skb;
|
|
|
|
if (tcp_sk(sk)->highest_sack == NULL)
|
|
tcp_sk(sk)->highest_sack = skb;
|
|
}
|
|
}
|
|
|
|
static inline void __tcp_add_write_queue_head(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
__skb_queue_head(&sk->sk_write_queue, skb);
|
|
}
|
|
|
|
/* Insert buff after skb on the write queue of sk. */
|
|
static inline void tcp_insert_write_queue_after(struct sk_buff *skb,
|
|
struct sk_buff *buff,
|
|
struct sock *sk)
|
|
{
|
|
__skb_queue_after(&sk->sk_write_queue, skb, buff);
|
|
}
|
|
|
|
/* Insert new before skb on the write queue of sk. */
|
|
static inline void tcp_insert_write_queue_before(struct sk_buff *new,
|
|
struct sk_buff *skb,
|
|
struct sock *sk)
|
|
{
|
|
__skb_queue_before(&sk->sk_write_queue, skb, new);
|
|
|
|
if (sk->sk_send_head == skb)
|
|
sk->sk_send_head = new;
|
|
}
|
|
|
|
static inline void tcp_unlink_write_queue(struct sk_buff *skb, struct sock *sk)
|
|
{
|
|
__skb_unlink(skb, &sk->sk_write_queue);
|
|
}
|
|
|
|
static inline bool tcp_write_queue_empty(struct sock *sk)
|
|
{
|
|
return skb_queue_empty(&sk->sk_write_queue);
|
|
}
|
|
|
|
static inline void tcp_push_pending_frames(struct sock *sk)
|
|
{
|
|
if (tcp_send_head(sk)) {
|
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
|
|
__tcp_push_pending_frames(sk, tcp_current_mss(sk), tp->nonagle);
|
|
}
|
|
}
|
|
|
|
/* Start sequence of the skb just after the highest skb with SACKed
|
|
* bit, valid only if sacked_out > 0 or when the caller has ensured
|
|
* validity by itself.
|
|
*/
|
|
static inline u32 tcp_highest_sack_seq(struct tcp_sock *tp)
|
|
{
|
|
if (!tp->sacked_out)
|
|
return tp->snd_una;
|
|
|
|
if (tp->highest_sack == NULL)
|
|
return tp->snd_nxt;
|
|
|
|
return TCP_SKB_CB(tp->highest_sack)->seq;
|
|
}
|
|
|
|
static inline void tcp_advance_highest_sack(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
tcp_sk(sk)->highest_sack = tcp_skb_is_last(sk, skb) ? NULL :
|
|
tcp_write_queue_next(sk, skb);
|
|
}
|
|
|
|
static inline struct sk_buff *tcp_highest_sack(struct sock *sk)
|
|
{
|
|
return tcp_sk(sk)->highest_sack;
|
|
}
|
|
|
|
static inline void tcp_highest_sack_reset(struct sock *sk)
|
|
{
|
|
tcp_sk(sk)->highest_sack = tcp_write_queue_head(sk);
|
|
}
|
|
|
|
/* Called when old skb is about to be deleted (to be combined with new skb) */
|
|
static inline void tcp_highest_sack_combine(struct sock *sk,
|
|
struct sk_buff *old,
|
|
struct sk_buff *new)
|
|
{
|
|
if (tcp_sk(sk)->sacked_out && (old == tcp_sk(sk)->highest_sack))
|
|
tcp_sk(sk)->highest_sack = new;
|
|
}
|
|
|
|
/* Determines whether this is a thin stream (which may suffer from
|
|
* increased latency). Used to trigger latency-reducing mechanisms.
|
|
*/
|
|
static inline bool tcp_stream_is_thin(struct tcp_sock *tp)
|
|
{
|
|
return tp->packets_out < 4 && !tcp_in_initial_slowstart(tp);
|
|
}
|
|
|
|
/* /proc */
|
|
enum tcp_seq_states {
|
|
TCP_SEQ_STATE_LISTENING,
|
|
TCP_SEQ_STATE_OPENREQ,
|
|
TCP_SEQ_STATE_ESTABLISHED,
|
|
TCP_SEQ_STATE_TIME_WAIT,
|
|
};
|
|
|
|
int tcp_seq_open(struct inode *inode, struct file *file);
|
|
|
|
struct tcp_seq_afinfo {
|
|
char *name;
|
|
sa_family_t family;
|
|
const struct file_operations *seq_fops;
|
|
struct seq_operations seq_ops;
|
|
};
|
|
|
|
struct tcp_iter_state {
|
|
struct seq_net_private p;
|
|
sa_family_t family;
|
|
enum tcp_seq_states state;
|
|
struct sock *syn_wait_sk;
|
|
int bucket, offset, sbucket, num;
|
|
kuid_t uid;
|
|
loff_t last_pos;
|
|
};
|
|
|
|
extern int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo);
|
|
extern void tcp_proc_unregister(struct net *net, struct tcp_seq_afinfo *afinfo);
|
|
|
|
extern struct request_sock_ops tcp_request_sock_ops;
|
|
extern struct request_sock_ops tcp6_request_sock_ops;
|
|
|
|
extern void tcp_v4_destroy_sock(struct sock *sk);
|
|
|
|
extern struct sk_buff *tcp_tso_segment(struct sk_buff *skb,
|
|
netdev_features_t features);
|
|
extern struct sk_buff **tcp_gro_receive(struct sk_buff **head,
|
|
struct sk_buff *skb);
|
|
extern int tcp_gro_complete(struct sk_buff *skb);
|
|
|
|
extern void __tcp_v4_send_check(struct sk_buff *skb, __be32 saddr,
|
|
__be32 daddr);
|
|
|
|
static inline u32 tcp_notsent_lowat(const struct tcp_sock *tp)
|
|
{
|
|
return tp->notsent_lowat ?: sysctl_tcp_notsent_lowat;
|
|
}
|
|
|
|
static inline bool tcp_stream_memory_free(const struct sock *sk)
|
|
{
|
|
const struct tcp_sock *tp = tcp_sk(sk);
|
|
u32 notsent_bytes = tp->write_seq - tp->snd_nxt;
|
|
|
|
return notsent_bytes < tcp_notsent_lowat(tp);
|
|
}
|
|
|
|
#ifdef CONFIG_PROC_FS
|
|
extern int tcp4_proc_init(void);
|
|
extern void tcp4_proc_exit(void);
|
|
#endif
|
|
|
|
/* TCP af-specific functions */
|
|
struct tcp_sock_af_ops {
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
|
|
struct sock *addr_sk);
|
|
int (*calc_md5_hash) (char *location,
|
|
struct tcp_md5sig_key *md5,
|
|
const struct sock *sk,
|
|
const struct request_sock *req,
|
|
const struct sk_buff *skb);
|
|
int (*md5_parse) (struct sock *sk,
|
|
char __user *optval,
|
|
int optlen);
|
|
#endif
|
|
};
|
|
|
|
struct tcp_request_sock_ops {
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
struct tcp_md5sig_key *(*md5_lookup) (struct sock *sk,
|
|
struct request_sock *req);
|
|
int (*calc_md5_hash) (char *location,
|
|
struct tcp_md5sig_key *md5,
|
|
const struct sock *sk,
|
|
const struct request_sock *req,
|
|
const struct sk_buff *skb);
|
|
#endif
|
|
};
|
|
|
|
extern int tcpv4_offload_init(void);
|
|
|
|
extern void tcp_v4_init(void);
|
|
extern void tcp_init(void);
|
|
|
|
#endif /* _TCP_H */
|