.\" This man page is Copyright (C) 1999 Andi Kleen .
.\" Permission is granted to distribute possibly modified copies
.\" of this page provided the header is included verbatim,
.\" and in case of nontrivial modification author and date
.\" of the modification is added to the header.
.\" $Id: tcp.7,v 1.1.1.1 2000/12/27 12:24:56 BitBIRD Exp $
.TH TCP 7 "25 Apr 1999" "Linux Man Page" "Linux Programmer's Manual" 
.\" İ Copyright (c) 2000 LetBright, Laser  www.linuxforum.net

.SH  NAME
tcp \- Э TCP
.SH  SYNOPSIS
.B #include <sys/socket.h>
.br
.B #include <netinet/in.h>
.br
.B tcp_socket = socket(PF_INET, SOCK_STREAM, 0);
.SH  DESCRIPTION
ЭǶ RFC973, RFC1122  RFC2001 Э
 NewReno  SACK 䲿ʵֵġ
ڽڻЭ
.BR ip (7)
֮ϵ׽֮ṩ˿ɿȫ˫ӡ
TCP Эȷݰ򵽴ﲢݰʧʱԶط
УÿݰУ (checksum)
Բ׽ݴʱTCP ¼ޡ

ʼ TCP ӿڲԶ˻򱾵ַûй涨ȷ
ڲһվ (outgoing) TCP ʱʹ
.BR connect (2)
׽ֽһӿڡ
ڽһվ (incoming) ʱ׽ʹ
.BR bind (2) 
ȡñصַͶ˿ڣȻ
.BR listen (2)
ʹ׽ֽ״̬

.BR accept (2).
Ϊÿһվ (incoming) ӽ׽֡
һѾ
.B accept

.B connect
ɹõ׽ֱʾȫȷԽݴ͡
״̬δӵӿ֮ݴͽܽС

Linux 2.2 ֧ RFC1323 TCP չô TCP ݻ
ָ֧ʱߴµĶӡΪʵЩܣӽ
뷢͵ݻǿʹ
.B net.core.wmem_default

.B net.core.rmem_default
sysctl ȫ趨,
.B SO_SNDBUF 

.B SO_RCVBUF 
׽ѡ׽ֽе趨
׽ֻߴ磬ܵȫֱ
.B net.core.rmem_max

.B net.core.wmem_max
 sysctl ơϸϸڣμ
.BR socket (7).
.PP 
TCP ֽ֧ݡ֪ͨշҪ촦
ҪϢͽݣ
.BR send (2).
ָ
.B MSG_OOB
ѡݽպں˷
.B SIGURG
źŵ̻Щ ioctl 
.B FIOCSPGRP

.B FIOCSETOWN 
׽ֵĽ̻飮

.B SO_OOBINLINE
׽ѡ, ôݱͨС
(
.B SIOCATMARK
ioctl ), ֻ
.BR sendmsg (2)
е
.B MSG_OOB
־ʱݲܱա 

.SH ַʽ ADDRESS FORMATS
TCP ǽ IP ֮(μ
.BR ip (7)).
.BR ip (7)
嶨ĵַʽҲ TCP.
TCPֵֻ֧ԵͨѶ֧ȫַּ㲥
.SH ϵͳ SYSCTLS
ͨ
.B /proc/sys/net/ipv4/* 
Ŀ¼µļ
ͨ
.BR sysctl (2)
ӿڽзЩ sysctl.
 IP sysctl Ҳͬ TCP; μ
.BR ip (7). 
.TP
.B tcp_window_scaling
 RFC1323 Э TCP ݴߴ.
.TP
.B tcp_sack
 RFC2018 Э TCP ѡȷ.
.TP
.B tcp_timestamps
 RFC1323 Э TCP ʱ.
.TP
.B tcp_fin_timeout
涨ǿȹر׽ǰȴݰ
ȷʵ TCP Эйع涨Υ
Ƿֹܾ񹥻Ҫġ
.TP
.B tcp_keepalive_probes
ݰǰ TCP . ӽ
.B SO_KEEPALIVE 
׽ѡʱű.
.TP
.B tcp_keepalive_time
ӲٴݵϷͱź֮
ĬΪ 10800 (3 Сʱ)
.TP
.B tcp_max_ka_probes
һʱ䷢ͱʱΪֹͻźţ
ֵ̫ߡ
.TP
.B tcp_stdurg
ʹ TCP ֶָѭ RFC973 Эеϸ͡ȱʡ£
ֶָʹ BSD ݣָָݺĵһֽڡ
 RFC973 Эָݺһֽڡһѡ
ɲ⡣
.TP
.B tcp_syncookies
 TCP ͬǩ(syncookie)ں˱
.BR CONFIG_SYN_COOKIES
б. ͬǩ(Syncookie)ֹһ׽йͼӵ
ʱĹءʹͬǩ(syncookie)ʱͻ̽ⲻ
һʱʱ̵Ĺ
.TP
.B tcp_max_syn_backlog
ÿӿдݶ (backlog) ȡLinux 2.2 ,
.BR listen (2)
еĶֻ˵ѽ׽дݶ(backlog)ȡ
ÿ׽ֵĻδ׽(
.B SYN_RECV
״̬е)г sysctl á
󵽴ʱLinux
ϵͳʼݰͬǩ(syncookie)óɴ򿪣
ݰܱӦʱֵԡ
.TP
.B tcp_retries1
Ӧһ TCP ǰźŵĴ
.TP
.B tcp_retries2
ѽͨѶ״̬һ TCP ݰǰطĴ
.TP
.B tcp_syn_retries
ڷͳʼͬݰ(SYN packet)ԶǰԵĴس
ϢֵС255Գվ(outgoing)ӳʱЧ
ڽվ(incoming)ط
.BR tcp_retries1
塣
.TP
.B tcp_retrans_collapse
طʱͼȫߴݰ
һЩջе TCP ȱ(BUG)
.\" tcp_rfc1337 δĵΪͻҡ
.SH ӿѡ SOCKET OPTIONS
ûȡ TCP ӿѡ
.BR getsockopt (2)
ж
.BR setsockopt (2)
ӿϵѡ͵
.BR SOL_TCP
ȥ.⣬
.B SOL_IP 
ӿ
ѡ TCP ӿҲáϣμ
.BR ip (7).
.TP
.B TCP_NODELAY
ر Nagle 㷨ζݰܿرͶû
иݰɵʱڴһʾIJ־
.TP
.B TCP_MAXSEG 
ûվ TCP ݶγߴ硣ѡڽǰ
ãı䷢͵һ˳ʼϢе MSS ֵֵ
MTU ӿֵԶá
.TP
.B TCP_CORK
ôͲ֡ŶӵIJֻ֡ڴ
ܷ͡ڵ
.BR sendfile (2)
ǰ׼ݱͷŻô
ѡ
.BR TCP_NODELAY
.
.SH  IOCTLS
Щ ioctl 
.BR ioctl (2)
зʡȷþ䷨Ϊ:
.PP
.RS
.nf
.BI int " value";
.IB error " = ioctl(" tcp_socket ", " ioctl_type ", &" value ");"
.fi
.RE
.TP
.B FIONREAD
ؽջŶӵδݵ
ָһָ롣
.TP
.B SIOCATMARK
ûѾнݣֵΪ 0
.BR SO_OOBINLINE
áǶԲԽָһָ롣
.TP
.B TIOCOUTQ
ڽӿ(socket)Ͷд
ָ뷵һֵ
.SH  ERROR HANDLING
緢ʱTCP Э齫·ݰ
طһʧܴ󣬲ʱ
.B ETIMEDOUT 
򱨸ڴϢ
.PP
ʱҪ⵽״̬ͨ
.B SOL_IP

.B IP_RECVERR
ӿѡ򿪺վ (incoming) 
͵ûССʹøѡ\-ʹ TCP Э·ɵĸ
״̬仯ݴ½
.SH ע NOTES
һʱһ
.B SIGPIPE
ӿд˲

.B SO_KEEPOPEN
ӿѡʱܽС
.PP
TCP ĶƵ(out-of-band); Ȼн
ݡ Linux ζ˷ͽʱɵĽ
ݽͨݲС(ʹ
.B SO_OOBINLINE
ֵûб). BSD ջ岻ͬ.

.PP
ȱʡ״̬£Linux ʹ BSD ݵĽֶָΡ RFC1122
ЭΥ, ջЭ໥Ҫ
.B tcp_stdurg
sysctl Ըı.

.SH ֪ ERRORS
.TP
.B EPIPE
һر׽ӻһر˵׽ֽж
.TP
.B ETIMEDOUT
һʱһ˲ȷطݡ
.TP
.B EAFNOTSUPPORT

.I sin_family
׽ֵַͶ
.BR AF_INET еġ
.PP
κζΪ
.BR ip (7)
ͨ׽ֳܷΪ TCP .
.PP

.SH ֮ BUGS
еĴĵ
.PP ûй IPv6 Ķ
.PP
ûй͸ѡ
.SH 汾 VERSIONS
й sysctl  Linux 2.2 ġ 
.B IP_RECVERR 
 Linux 2.2 еԡ
.B TCP_CORK 
 2.2 µ.
.SH ּ SEE ALSO
.BR socket (7),
.BR socket (2),
.BR ip (7),
.BR sendmsg (2),
.BR recvmsg (2).
.br
RFC793 Эж TCP й.
.br
RFC1122 Эж TCP Ҫһݹ Nagle 㷨
.br
RFC2001 ЭһЩ TCP 㷨
.SH "[İά]"
LetBright E-mail: letbright@netease.com
.SH "[ݸ]" 2000/10/21
.br
.Bй Linux ̳ man ֲҳƻ: www.cmpp.net/