.\" manҳȨ(C)1999 Andi Kleen<ak@muc.de>.
.\" ޸ĵĸҳ汾ҪȨ,һֲذheader(ͷʶ),
.\" ˽ϴ޸ĵ,޸ߺӵheader.
.\" İȨ riser,BitBIRD www.linuxforum.net 2000
.\" $Id: udp.7,v 1.1.1.1 2000/12/27 12:24:44 BitBIRD Exp $
.TH UDP  7 "1998102" "Linux ֲҳ" "Linux Աֲ"
.SH NAME ()
udp \- IPv4  UDP Э.
.SH SYNOPSIS ()
.B #include <sys/socket.h>
.br
.B #include <netinet/in.h>
.br
.B udp_socket = socket(PF_INET, SOCK_DGRAM, 0);

.SH DESCRIPTION()
һ RFC768 еûݱЭʵ.
ʵӵ, ɿݱϢ.
ϢǴ䵽֮ǰظ.
UDP ͨɺͼУ.

һ UDP ׽ʱ, ıغԶ̵ַDzȷ.
ʹôһЧĿĵַΪ
.BR sendto (2)

.BR sendmsg (2)
ݱ.׽ϵ
.BR connect (2)
ʱ, ĬϵĿĵַ, ݱʹ
.BR send (2)

.BR write (2)
ͶҪָĿĵַ.
Ҳͨһַ
.BR sendto (2)

.BR sendmsg (2)
͵Ŀĵַ.
Ϊ˽Ϣ,׽ֱ
.BR bind (2)
һصַ,
ûô, 
׽ֲڵһûʱԶһض˿.

нղֻһϢ.
ϢСݵĻʱ, ֻЩ, 
ϢݵĻʱ,ضϢ
.B MSG_TRUNC
־.

IP ѡʹ
.BR ip "(7)"
е׽ѡͻ.
ֻд˺ʵ sysctl ʱ,
ں˲Ŵ(ʹر, Ȼᴫݸû).
μ
.BR ip "(7)" .


.B MSG_DONTROUTE
־,ʱĿĵַָһؽӿڵַ,
Ϣֻýӿ.

 UDP ܳӿ MTU(Maximum Transmission Unit 䵥Ԫ)ʱ,
UDP Ϣзֶ.
һΪѺõĿѡʹ path MTU discovery(·MTU),

.BR ip (7)
е
.B IP_PMTU_DISCOVER
.

.SH ADDRESS FORMAT (ַʽ)
UDP ʹ IPv4 
.B sockaddr_in
ַʽ,
.BR ip (7)
.

.SH ERROR HANDLING ()
ش󶼻Դ󷵻ֵķʽݸû,
ʹ׽û.ִʽб
BSD ׽ʵַ, ׽, Щᴫκδ,
Linux Ĵʽѭ
.B RFC1122
Ҫ.

ΪǰĴ,
.B SO_BSDCOMPAT
SOL_SOCKET ѡֻ׽ӵ½Զ̴(
.B EPROTO

.BR EMSGSIZE )
.
޸벢ʵش, Ҫ򿪸ѡ.
زĴǴ.


.B IP_RECVERR
ѡʱ, дԴ洢׽ִ,
ͨ
.B MSG_ERRQUEUE
ʶõ
.BR recvmsg (2)
.

.SH ERRORS ()

.BR socket (7)

.BR ip (7)
еĴ󶼿һ UDP ׽շʱյ.

.B ECONNREFUSED
ûĿĵַĽ.
ǰһͨ׽ַ͵Ϣ.

.SH VERSIONS(汾)
IP_RECVERR  Linux 2.2 е¹.

.SH CREDITS(βע)
ֲҳΪ Andi Kleen.

.SH SEE ALSO()
.BR ip (7),
.BR socket (7),
.BR raw (7).

RFC768: ûݱЭ.
.br
RFC1122: 
.br
RFC1191:  path MTU discovery (·MTU).

.SH "[İά]"
riser Email:boomer@ccidnet.com
.SH "[ݸ]"
2000/11/10

.SH "[йLinux̳manֲҳƻ]"
.TP
.BI www.cmpp.net/