xref: /titanic_41/usr/src/man/man3xnet/inet_ntop.3xnet (revision 6a1af1a67532df169a657cce07140be64bdea084)
te
Copyright (c) 2001, The IEEE and The Open Group. All Rights Reserved. Portions Copyright (c) 2003, Sun Microsystems, Inc. All Rights Reserved.
Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.
The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
This notice shall appear on any product containing this material.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
inet_ntop 3XNET "1 Nov 2003" "SunOS 5.11" "X/Open Networking Services Library Functions"
NAME
inet_ntop, inet_pton - convert IPv4 and IPv6 addresses between binary and text form
SYNOPSIS

cc [ flag ... ] file ... -lxnet [ library ... ]
#include <arpa/inet.h>

const char *inet_ntop(int af, const void *restrict src,
 char *restrict dst, socklen_t size);

int inet_pton(int af, const char *restrict src, dst);
DESCRIPTION

The inet_ntop() function converts a numeric address into a text string suitable for presentation. The af argument specifies the family of the address. This can be AF_INET or AF_INET6. The src argument points to a buffer holding an IPv4 address if the af argument is AF_INET, or an IPv6 address if the af argument is AF_INET6. The dst argument points to a buffer where the function stores the resulting text string; it cannot be NULL. The size argument specifies the size of this buffer, which must be large enough to hold the text string (INET_ADDRSTRLEN characters for IPv4, INET6_ADDRSTRLEN characters for IPv6).

The inet_pton() function converts an address in its standard text presentation form into its numeric binary form. The af argument specifies the family of the address. The AF_INET and AF_INET6 address families are supported. The src argument points to the string being passed in. The dst argument points to a buffer into which the function stores the numeric address; this must be large enough to hold the numeric address (32 bits for AF_INET, 128 bits for AF_INET6).

If the af argument of inet_pton() is AF_INET, the src string is in the standard IPv4 dotted-decimal form:

ddd.ddd.ddd.ddd

where "ddd"is a one to three digit decimal number between 0 and 255 (see inet_addr(3XNET)). The inet_pton() function does not accept other formats (such as the octal numbers, hexadecimal numbers, and fewer than four numbers that inet_addr() accepts).

If the af argument of inet_pton() is AF_INET6, the src string is in one of the following standard IPv6 text forms:

1. The preferred form is "x:x:x:x:x:x:x:x", where the 'x's are the hexadecimal values of the eight 16-bit pieces of the address. Leading zeros in individual fields can be omitted, but there must be at least one numeral in every field.

2. A string of contiguous zero fields in the preferred form can be shown as "::". The "::" can only appear once in an address. Unspecified addresses ("0:0:0:0:0:0:0:0") can be represented simply as "::".

3. A third form that is sometimes more convenient when dealing with a mixed environment of IPv4 and IPv6 nodes is "x:x:x:x:x:x:d.d.d.d", where the 'x's are the hexadecimal values of the six high-order 16-bit pieces of the address, and the 'd's are the decimal values of the four low-order 8-bit pieces of the address (standard IPv4 representation).

A more extensive description of the standard representations of IPv6 addresses can be found in RFC 2373.

RETURN VALUES

The inet_ntop() function returns a pointer to the buffer containing the text string if the conversion succeeds. Otherwise it returns NULL and sets errno to indicate the error.

The inet_pton() function returns 1 if the conversion succeeds, with the address pointed to by dst in network byte order. It returns 0 if the input is not a valid IPv4 dotted-decimal string or a valid IPv6 address string. It returns -1 and sets errno to EAFNOSUPPORT if the af argument is unknown.

ERRORS

The inet_ntop() and inet_pton() functions will fail if:

EAFNOSUPPORT

The af argument is invalid.

ENOSPC

The size of the inet_ntop() result buffer is inadequate.

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPEATTRIBUTE VALUE
Interface StabilityStandard
MT-LevelMT-Safe
SEE ALSO

inet_addr(3XNET), attributes(5)