.\"	$NetBSD: cltp.4,v 1.3 1994/11/30 16:22:08 jtc Exp $
.\"
.\" Copyright (c) 1990, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\"    must display the following acknowledgement:
.\"	This product includes software developed by the University of
.\"	California, Berkeley and its contributors.
.\" 4. Neither the name of the University nor the names of its contributors
.\"    may be used to endorse or promote products derived from this software
.\"    without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\"     @(#)cltp.4	8.1 (Berkeley) 6/9/93
.\"
.Dd June 9, 1993
.Dt CLTP 4
.Os
.Sh NAME
.Nm cltp
.Nd
.Tn ISO
Connectionless Transport Protocol
.Sh SYNOPSIS
.Fd #include <sys/socket.h>
.Fd #include <netiso/iso.h>
.Ft int
.Fn socket AF_ISO SOCK_DGRAM 0
.Sh DESCRIPTION
.Tn CLTP
is a simple, unreliable datagram protocol which is accessed
via the
.Dv SOCK_DGRAM
abstraction for the
.Tn ISO
protocol family.
.Tn CLTP
sockets are connectionless, and are
normally used with the
.Xr sendto
and
.Xr recvfrom
calls, though the
.Xr connect 2
call may also be used to fix the destination for future
packets (in which case the
.Xr recv 2
or
.Xr read 2
and
.Xr send 2
or
.Xr write 2
system calls may be used).
.Pp
.Tn CLTP
address formats are identical to those used by TP.
In particular
.Tn CLTP
provides a service selector in addition
to the normal
.Tn ISO NSAP .
Note that the
.Tn CLTP
selector
space is separate from the TP selector space (i.e. a
.Tn CLTP
selector
may not be
.Dq connected
to a TP selector).
.Pp
Options at the
.Tn CLNP
network level may be used with
.Tn CLTP ;
see
.Xr clnp 4 .
.Sh DIAGNOSTICS
A socket operation may fail with one of the following errors returned:
.Bl -tag -width [EADDRNOTAVAIL]
.It Bq Er EISCONN
when trying to establish a connection on a socket which
already has one, or when trying to send a datagram with the destination
address specified and the socket is already connected;
.It Bq Er ENOTCONN
when trying to send a datagram, but
no destination address is specified, and the socket hasn't been
connected;
.It Bq Er ENOBUFS
when the system runs out of memory for
an internal data structure;
.It Bq Er EADDRINUSE
when an attempt
is made to create a socket with a selector which has already been
allocated;
.It Bq Er EADDRNOTAVAIL
when an attempt is made to create a
socket with a network address for which no network interface
exists.
.El
.Sh SEE ALSO
.Xr getsockopt 2 ,
.Xr recv 2 ,
.Xr send 2 ,
.Xr socket 2 ,
.Xr clnp 4 ,
.Xr iso 4 ,
.Xr netintro 4