xref: /illumos-gate/usr/src/lib/libc/port/inet/inet_ntoa.c (revision 8a7aa2a5)

/*
 * CDDL HEADER START
 *
 * 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]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
 * Portions of this source code were derived from Berkeley
 * 4.3 BSD under license from the Regents of the University of
 * California.
 */

/*
 * Copyright (c) 1983, 1990, 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.
 */

/*
 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies, and that
 * the name of Digital Equipment Corporation not be used in advertising or
 * publicity pertaining to distribution of the document or software without
 * specific, written prior permission.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * Convert network-format internet address
 * to base 256 d.d.d.d representation.
 *
 * Reentrant interface
 */

#include "lint.h"
#include "thr_uberdata.h"

#include <sys/types.h>

#include <netinet/in.h>

#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>

char *
inet_ntoa_r(struct in_addr in, char b[])
{
	char	*p;

	p = (char *)&in;
#define	UC(b)	(((int)b)&0xff)
	(void) sprintf(b, "%d.%d.%d.%d",
	    UC(p[0]), UC(p[1]), UC(p[2]), UC(p[3]));
	return (b);
}

char *
inet_ntoa(struct in_addr in)
{
	return (inet_ntoa_r(in, curthread->ul_ntoabuf));
}

/*
 * Check whether "cp" is a valid ascii representation
 * of an Internet address and convert to a binary address.
 * Returns 1 if the address is valid, 0 if not.
 * This replaces inet_addr, the return value from which
 * cannot distinguish between failure and a local broadcast address.
 */
int
inet_aton(const char *cp, struct in_addr *addr)
{
	uint32_t val;
	int base, n;
	char c;
	unsigned int parts[4];
	unsigned int *pp = parts;

	c = *cp;
	for (;;) {
		/*
		 * Collect number up to ``.''.
		 * Values are specified as for C:
		 * 0x=hex, 0=octal, isdigit=decimal.
		 */
		if (!isdigit(c))
			return (0);
		val = 0; base = 10;
		if (c == '0') {
			c = *++cp;
			if (c == 'x' || c == 'X')
				base = 16, c = *++cp;
			else
				base = 8;
		}
		for (;;) {
			if (isascii(c) && isdigit(c)) {
				val = (val * base) + (c - '0');
				c = *++cp;
			} else if (base == 16 && isascii(c) && isxdigit(c)) {
				val = (val << 4) |
				    (c + 10 - (islower(c) ? 'a' : 'A'));
				c = *++cp;
			} else
				break;
		}
		if (c == '.') {
			/*
			 * Internet format:
			 *	a.b.c.d
			 *	a.b.c	(with c treated as 16 bits)
			 *	a.b	(with b treated as 24 bits)
			 */
			if (pp >= parts + 3)
				return (0);
			*pp++ = val;
			c = *++cp;
		} else
			break;
	}
	/*
	 * Check for trailing characters.
	 */
	if (c != '\0' && (!isascii(c) || !isspace(c)))
		return (0);
	/*
	 * Concoct the address according to
	 * the number of parts specified.
	 */
	n = pp - parts + 1;
	switch (n) {

	case 0:
		return (0);		/* initial nondigit */

	case 1:				/* a -- 32 bits */
		break;

	case 2:				/* a.b -- 8.24 bits */
		if ((val > 0xffffff) || (parts[0] > 0xff))
			return (0);
		val |= parts[0] << 24;
		break;

	case 3:				/* a.b.c -- 8.8.16 bits */
		if ((val > 0xffff) || (parts[0] > 0xff) || (parts[1] > 0xff))
			return (0);
		val |= (parts[0] << 24) | (parts[1] << 16);
		break;

	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
		if ((val > 0xff) || (parts[0] > 0xff) || (parts[1] > 0xff) ||
		    (parts[2] > 0xff))
			return (0);
		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
		break;
	}
	if (addr)
		addr->s_addr = htonl(val);
	return (1);
}

/*
 * Internet address interpretation routine.
 * All the network library routines call this
 * routine to interpret entries in the data bases
 * which are expected to be an address.
 * The value returned is in network order.
 */
in_addr_t
inet_addr(const char *cp)
{
	struct in_addr val;

	if (inet_aton(cp, &val))
		return (val.s_addr);
	return (INADDR_NONE);
}

/*
 * Return the network number from an internet
 * address; handles class a/b/c network #'s.
 */
in_addr_t
inet_netof(struct in_addr in)
{
	uint32_t i = ntohl(in.s_addr);

	if (IN_CLASSA(i))
		return ((i & IN_CLASSA_NET) >> IN_CLASSA_NSHIFT);
	if (IN_CLASSB(i))
		return ((i & IN_CLASSB_NET) >> IN_CLASSB_NSHIFT);
	return ((i & IN_CLASSC_NET) >> IN_CLASSC_NSHIFT);
}