.\" Copyright (c) 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.
.\"
.\"     @(#)iso_addr.3	8.1 (Berkeley) 6/4/93
.\"     $Id$
.\"
.Dd June 4, 1993
.Dt ISO_ADDR 3
.Os
.Sh NAME
.Nm iso_addr ,
.Nm iso_ntoa
.Nd "elementary network address conversion routines for Open System Interconnection
.Sh SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <netiso/iso.h>
.Ft struct iso_addr *
.Fn iso_addr "char *cp"
.Ft char *
.Fn iso_ntoa "struct iso_addr *isoa"
.Sh DESCRIPTION
The routine
.Fn iso_addr
interprets character strings representing
.Tn OSI
addresses, returning binary information suitable
for use in system calls.
The routine
.Fn iso_ntoa
takes
.Tn OSI
addresses and returns
.Tn ASCII
strings representing NSAPs (network service
access points) in a
notation inverse to that accepted by 
.Fn iso_addr .
.Pp
Unfortunately, no universal standard exists for representing
.Tn OSI
network addresses.
.Pp
The format employed by
.Fn iso_addr
is a sequence of hexadecimal
.Dq digits
(optionally separated by periods),
of the form:
.Bd -filled -offset indent
<hex digits>.<hex digits>.<hex digits>
.Ed
.Pp
Each pair of hexadecimal digits represents a byte
with the leading digit indicating the higher-ordered bits.
A period following an even number of bytes has no
effect (but may be used to increase legibility).
A period following an odd number of bytes has the
effect of causing the byte of address being translated
to have its higher order bits filled with zeros.
.Sh RETURN VALUES
.Fn iso_ntoa
always returns a null terminated string.
.Fn iso_addr
always returns a pointer to a struct iso_addr.
(See
.Sx BUGS . )
.Sh SEE ALSO
.Xr iso 4
.Sh HISTORY
The
.Fn iso_addr
and
.Fn iso_ntoa
functions appeared in 
.Bx 4.3 Reno .
.Sh BUGS
The returned values
reside in a static memory area.
.Pp
The function
.Fn iso_addr
should diagnose improperly formed input, and there should be an unambiguous
way to recognize this.