'\" t
.\" Don't change the first line, it tells man that we need tbl.
.\" This man page is Copyright (C) 1999 Andi Kleen .
.\" and copyright (c) 1999 Matthew Wilcox. 
.\" 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: socket.7,v 1.1.1.1 2000/12/27 12:25:12 BitBIRD Exp $
.TH SOCKET  7 "7 May 1999" "Linux Man Page" "Linux Programmer's Manual" 
.SH  [NAME]
socket \- Linux ׽
.SH 
.B #include  <sys/socket.h>
.br
.IB mysocket " = socket(int " socket_family ", int " socket_type ", int " protocol );

.SH 
ֲҳ Linux ׽ֵûӿ.  BSD ׽ǽ
ںЭջ֮ͳһӿ, Эģڲͬ
.I Э
,
.BR PF_INET ", " PF_IPX ", " PF_PACKET

.I ׽
,
.B ֽSOCK_STREAM

.BR ݱSOCK_DGRAM.
Э׽ο
.BR socket (2) "."

.SH ׽Ӳ㺯
ûͨЩ׽ֺͺͽհ, Լ׽ֲ.
ϸ˵οǸԵֲҳ.

.BR socket (2)
׽֣
.PP
.BR connect (2)
Զ׽ֵַ
.PP
.BR bind (2)
׽ֺһ׽ֵַһΪ׽ַһЭַ
.PP
.BR listen (2)
֪ͨ׽ֽµ
.PP
.BR accept (2)
Ϊµӻµ
.PP
.BR socketpair (2)
ӵ׽֣ijЩвʵ,
.BR PF_UNIX ""
.PP
.BR send (2),
.PP
.BR sendto (2),

.BR sendmsg (2)
ͨ׽ַݣ
.BR recv (2),
.BR recvfrom (2),
.BR recvmsg (2)
׽ֽ.
.BR poll (2)

.PP
.BR select (2)
ȴݵ׼ý. ֮, ׼ I/O 
.BR write (2),
.BR writev (2),
.BR sendfile (2),
.BR read (2),

.BR readv (2) 
Ҳ루գдͣ.
.PP
.BR getsockname (2)
ڻñ׽ֵַ
.PP
.BR getpeername (2)
ڻԶ׽ֵַ.
.BR getsockopt (2)

.BR setsockopt (2)
ûȡ׽ֻЭѡ. 
.BR ioctl (2)
ҲûȡһЩѡ.
.PP
.BR close (2)
ر׽.
.BR shutdown (2)
رȫ˫׽ӵһ.
.PP
׽ֲ֧Ҳֵ֧
.BR pread (2) 

.BR pwrite (2)
з 0 λõIJ.

.BR fcntl (2).

.B O_NONBLOCK
־ʵֶ׽ֵķ I/O 
.B O_NONBLOCK
Ǵ accept ̳ģȻԭлIJ᷵
.BR EAGAIN .
.BR connect (2) 
ڴ·
.B EINPROGRESS
.
ûͨ
.BR poll (2)

.BR select (2)
ȴ¼.

.PP
.TS
tab(:) allbox;
c s s
l l l.
I/O ¼
¼:ѯ־:¼
:POLLIN:T{
ݵ.
T}
:POLLIN:T{
(ӵ׽)ӳɹ
T}
:POLLHUP:T{
һ׽ַϿ.
T}
:POLLHUP:T{
(Э)׽дʱӶϿ. ͬʱ
.B SIGPIPE.
T}
д:POLLOUT:T{
׽гķͻд.
T}
/д:T{
POLLIN|
.br
POLLOUT
T}:T{

.BR connect (2)
.
T}
/д:POLLERR:һ첽.
/д:POLLHUP:ԷѾر.
:POLLPRI:T{
ݵ.Ȼ
.B SIGURG.
T}
.\" XXX not true currently
.\" It is no I/O event when the connection
.\" is broken from the local end using 
.\" .BR shutdown (2)
.\" or 
.\" .BR close (2)
.\" .
.TE

.PP
һ poll/select ں
.B SIGIO
ź֪ͨӦó. ҪôõĻ
.BR fcntl (2)
׽ļ
.B FASYNC
־
.BR sigaction (2).

.B SIGIO
źһЧźŴ.ο
.I SIGNALS
.
.SH ׽ѡ
׽ѡ
.BR setsockopt (2)
ã
.BR getsockopt (2)
ȡ׽ּΪ
.B SOL_SOCKET 
׽ֵ׽ѡ:
.TP
.B SO_KEEPALIVE
ӵ׽Ϸ keep\-alive ϢĹ.һ.
.TP
.B SO_OOBINLINE
ѡ⣨Out\-of\-Bandݿֱӷ
ֻнʱ
.B MSG_OOB 
־, Žմ.
.\" don't document it because it can do too much harm.
.\".B SO_NO_CHECK
.TP
.BR SO_RCVLOWAT "  " SO_SNDLOWAT
ڿʼЭ
.RB ( SO_SNDLOWAT ) 
ڽݵû
.RB ( SO_RCVLOWAT ).
֮ǰڵСֽ.  Linux ֵDzɸı,
̶Ϊ 1 ֽ.

.B getsockopt 
ȡǵֵ; 
.B setsockopt 
Ƿ
.BR ENOPROTOOPT .  
.TP
.BR SO_RCVTIMEO "  " SO_SNDTIMEO
ͺͽʱijʱ趨, ڳʱʱ.  Linux 
Эָ, ܱд. ǵĹܿ
.BR alarm (2)

.BR setitimer (2).
ģ.
.TP
.B SO_BSDCOMPAT
 BSD  bug\-to\-bug . һֻ UDP Эģʹö
ҽҪȡ. Ļ, UDP ׽ֽյ ICMP 󽫲
ᱻû. Linux 2.0 жԭʼ׽Ҳ BSD 
bug\-to\-bug ݣͷı,ʡԹ㲥ʶ, Linux 2.2
ȡһ. ޸ûķʽȽϺ.
.TP
.B SO_PASSCRED
ر
.B SCM_CREDENTIALS
ϢĽ.
Ϣμ
.BR unix (7). 
.TP
.B SO_PEERCRED
׽ֵⲿ̵֤. ֻ 
.B PF_UNIX 
׽.μ 
.BR unix (7). 
Ϊ
.B ucred 
ṹ.ֻ
.BR getsockopt .
Ч.
.TP
.B SO_BINDTODEVICE
׽ְ󶨵һض豸, \(lqeth0\(rq,
ΪָĽӿִ. ǿַΪ 0,
׽豸󶨱ȡ. ȥѡһ䳤Ŀβ
ӿƵַ, 󳤶Ϊ
.BR IFNAMSIZ . 
һ׽ֱһӿ,
ֻضӿڽյϢɴ׽ִ.
.TP
.B SO_DEBUG 
׽ֵ.ֻ
.B CAP_NET_ADMIN
ܻЧûʶΪ 0 ĽЧ.
.TP
.B SO_REUSEADDR
ʾһ
.BR bind (2) 
жṩĵַʹõȷϹӦظʹñصַ. 
.B PF_INET
׽, ʾ׽ֿ԰, һԾ
ӿڰ󶨵˵ַ. ׽ֺһָ˿ڰΪ
.B INADDR_ANY
ʱ, Ͳٰ󶨵καصַĴ˶˿.
.TP
.B SO_TYPE
׽ͣ
.BR SOCK_STREAM  
ֻͨ
.BR getsockopt
ȡ. 
.TP
.B SO_DONTROUTE
ͨط, ֻܷ͸ֱӵ.ͨ׽ֵ
.BR send (2)

.B MSG_DONTROUTE
־ʵͬЧ. ֵΪıʶ.
.TP
.B SO_BROADCAST
ûȡ㲥ʶ. ѡѡʱ, ݱ׽ֽ
㲥ַ͵ݰ, ҿ㲥ַݰ. һ
ѡ׽Ч.
.TP
.B SO_SNDBUF 
ûõ׽ַͻֽ. Ĭֵ 
.B wmem_default 
sysctl ,ֵ
.B wmem_max
sysctl .
.TP
.B SO_RCVBUF
ûõ׽ֽջֽĬֵ 
.B rmem_default 
sysctl,ֵ
.B rmem_max
sysctl .
.TP
.B SO_LINGER
ûȡ
.B SO_LINGER 
ѡֵ. Ϊ
.B linger 
ṹ.
.PP
.RS
.nf
.ta 4n 10n 22n
struct linger {
	int	l_onoff;	/* ʱ״̬/رգ */
	int	l_linger;	/* ʱ೤ʱ */
};
.ta
.fi
.RE
.IP
ѡѡ,
.BR close (2)

.BR shutdown (2)
ȵ׽ŶӵϢɹͻ򵽴ӳʱ
Ż᷵. , ý.  closing ں̨
. ׽
.BR exit (2),
һֹرʱ, ں̨ӳٽе.
.TP
.B SO_PRIORITY
ڴ׽ַ͵аЭ鶨Ȩ.
Linux ͨһֵ: ѡ豸Ŷӹ, 
иȨİȱ.
.BR ip (7),
ͬʱҲ IP ͣTOS.
.TP
.B SO_ERROR
ȡòδ׽ִ. ֻ
.BR getsockopt .
ʱЧ. һֵ.
.SH SIGNALS
һѹرգػԶնˣӵ׽дʱ,
д̷
.B SIGPIPE
źţ
.B EPIPE
.
д
.B MSG_NOSIGNAL 
ʶʱ, ᷢź.
.PP

.B FIOCSETOWN 
fcntl  
.B SIOCSPGRP 
ioctl һô I/O ¼ʱ
.B SIGIO
ǾͿźžʹ
.BR poll (2)

.BR select (2)
ҳ¼׽.
һѡ Linux 2.2 У
.B F_SETSIG
fcntl һʵʱź:
ʵʱźŵĴ򱻵ʱյ
.IR siginfo_t 

.I si_fd 
еļ.
Ϣμ
.BR fcntl (2)
.PP
ijЩУ:̷ʵ׽֣,

.B SIGIO
Ķڽ̶źӦʱѾʧ.
Ļ, Ӧٴεȴ, Ϊ Linux Ժطź.
.\" .SHϢ
.SH SYSCTLS 
ͨĿ¼
.B /proc/sys/net/core/* 
µļ
.BR sysctl (2) 
ϵͳں׽ֵϵͳƣsysctlϢ.
.TP
.B rmem_default
ָ׽ֽջĬֽ.
.TP
.B rmem_max
ָ׽ֽջֽ, ûͨʹ
.B SO_RCVBUF
׽ѡôֵ.
.TP
.B wmem_default
ָ׽ַͻĬֽ.
.TP
.B wmem_max
ָͻֽûͨʹ׽ֵ
.B SO_SNDBUF
ѡֵ.
.TP
.BR message_cost "  " message_burst 
趨ǺŴ洢Ͱ, ڴ洢Ͱбһⲿ
¼µľϢ.
.TP
.B netdev_max_backlog 
ȫаĿ.
.TP
.B optmem_max
ÿ׽ֵ iovecs ĸݺûݵ󳤶.
.\" netdev_fastroute ûн
.SH IOCTLS
ϵ IO ֵͨ
.BR ioctl (2)
:

.RS
.nf
.IB error " = ioctl(" ip_socket ", " ioctl_type ", " &value_result ");"
.fi
.RE

.TP
.B SIOCGSTAMP

.B timeval 
͵Ľṹаз͸ûһʱʱ
ȷ RTT round trip time ʱ.
.BR "struct timeval" .
ṹ˵ο
.BR setitimer (2) 
.\"
.TP
.BR SIOCSPGRP
첽 IO ߽յʱý̻飬
ǣ
.B SIGIO

.B SIGURG
ź, Ϊָ
.BR pid_t . 
͵ָ롣ΪźŵӦĽ̡Ϊ
źŵ˲ֵ id Ľн̡
û
.B CAP_KILL
ܻЧ UID  0, ֻѡԼԼĽ
ź.
.TP
.B FIOASYNC
ı
.B O_ASYNC
־򿪻߹ر׽ֵ첽 IO ģʽ첽IOģʽָǣ
µ I/O ¼ʱ
.B SIGIO 
źŻ
.B F_SETSIG
õź.
.IP
Ϊβ. 
.\"
.TP
.BR SIOCGPGRP
õǰ
.B SIGIO 

.B SIGURG
źŵĽ̻߽, 
źŶû, Ϊ 0.
.PP
Ч fcntl:
.TP
.BR FIOCGETOWN 
 IO е SIOCGPGRP ͬ.
.TP
.BR FIOCSETOWN
 IO е SIOCSPGRP ͬ.
.SH ע
Linux һķ/ջں˽ṹ, , 
ϵͳƵĻɷʵĻ.
.SH ȱ
.B CONFIG_FILTER 
ûн
.B SO_ATTACH_FILTER 

.B SO_DETACH_FILTER 
׽ѡ.  libpcap д˽ӿڵ˵
.SH VERSIONS 汾
.B SO_BINDTODEVICE 
 Linux 2.0.30 . 
.B SO_PASSCRED 
 Linux 2.2 ѡ.
sysctl  Linux 2.2. ¸ 
.SH 
ֲҳ Andi Kleen д.
.PP
.SH ּ
.BR socket (2),
.BR ip (7),
.BR setsockopt (2),
.BR getsockopt (2),
.BR packet (7),
.BR ddp (7) 

.SH "[İά]"
liguoping: Email: liguoping_11@sina.com
.SH "[ݸ]"
2000/11/06

.SH "[й Linux ̳ man ֲҳƻ]"
.TP
.BI www.cmpp.net/