1.\" Copyright (c) 1990, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" %sccs.include.redist.man% 5.\" 6.\" @(#)cltp.4 8.1 (Berkeley) 06/09/93 7.\" 8.Dd 9.Dt CLTP 4 10.Os 11.Sh NAME 12.Nm cltp 13.Nd 14.Tn ISO 15Connectionless Transport Protocol 16.Sh SYNOPSIS 17.Fd #include <sys/socket.h> 18.Fd #include <netiso/iso.h> 19.Ft int 20.Fn socket AF_ISO SOCK_DGRAM 0 21.Sh DESCRIPTION 22.Tn CLTP 23is a simple, unreliable datagram protocol which is accessed 24via the 25.Dv SOCK_DGRAM 26abstraction for the 27.Tn ISO 28protocol family. 29.Tn CLTP 30sockets are connectionless, and are 31normally used with the 32.Xr sendto 33and 34.Xr recvfrom 35calls, though the 36.Xr connect 2 37call may also be used to fix the destination for future 38packets (in which case the 39.Xr recv 2 40or 41.Xr read 2 42and 43.Xr send 2 44or 45.Xr write 2 46system calls may be used). 47.Pp 48.Tn CLTP 49address formats are identical to those used by TP. 50In particular 51.Tn CLTP 52provides a service selector in addition 53to the normal 54.Tn ISO NSAP . 55Note that the 56.Tn CLTP 57selector 58space is separate from the TP selector space (i.e. a 59.Tn CLTP 60selector 61may not be 62.Dq connected 63to a TP selector). 64.Pp 65Options at the 66.Tn CLNP 67network level may be used with 68.Tn CLTP ; 69see 70.Xr clnp 4 . 71.Sh DIAGNOSTICS 72A socket operation may fail with one of the following errors returned: 73.Bl -tag -width [EADDRNOTAVAIL] 74.It Bq Er EISCONN 75when trying to establish a connection on a socket which 76already has one, or when trying to send a datagram with the destination 77address specified and the socket is already connected; 78.It Bq Er ENOTCONN 79when trying to send a datagram, but 80no destination address is specified, and the socket hasn't been 81connected; 82.It Bq Er ENOBUFS 83when the system runs out of memory for 84an internal data structure; 85.It Bq Er EADDRINUSE 86when an attempt 87is made to create a socket with a selector which has already been 88allocated; 89.It Bq Er EADDRNOTAVAIL 90when an attempt is made to create a 91socket with a network address for which no network interface 92exists. 93.El 94.Sh SEE ALSO 95.Xr getsockopt 2 , 96.Xr recv 2 , 97.Xr send 2 , 98.Xr socket 2 , 99.Xr intro 4 , 100.Xr iso 4 , 101.Xr clnp 4 102