inet_addr.c revision 1.7 
1/*	$OpenBSD: inet_addr.c,v 1.7 2003/06/02 20:18:35 millert Exp $	*/
2
3/*
4 * ++Copyright++ 1983, 1990, 1993
5 * -
6 * Copyright (c) 1983, 1990, 1993
7 *    The Regents of the University of California.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 3. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 * -
33 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
34 *
35 * Permission to use, copy, modify, and distribute this software for any
36 * purpose with or without fee is hereby granted, provided that the above
37 * copyright notice and this permission notice appear in all copies, and that
38 * the name of Digital Equipment Corporation not be used in advertising or
39 * publicity pertaining to distribution of the document or software without
40 * specific, written prior permission.
41 *
42 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
43 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
44 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
45 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
46 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
47 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
48 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
49 * SOFTWARE.
50 * -
51 * --Copyright--
52 */
53
54#if defined(LIBC_SCCS) && !defined(lint)
55#if 0
56static char sccsid[] = "@(#)inet_addr.c	8.1 (Berkeley) 6/17/93";
57static char rcsid[] = "$From: inet_addr.c,v 8.5 1996/08/05 08:31:35 vixie Exp $";
58#else
59static char rcsid[] = "$OpenBSD: inet_addr.c,v 1.7 2003/06/02 20:18:35 millert Exp $";
60#endif
61#endif /* LIBC_SCCS and not lint */
62
63#include <sys/types.h>
64#include <sys/param.h>
65#include <netinet/in.h>
66#include <arpa/inet.h>
67#include <ctype.h>
68
69/*
70 * Ascii internet address interpretation routine.
71 * The value returned is in network order.
72 */
73in_addr_t
74inet_addr(cp)
75	register const char *cp;
76{
77	struct in_addr val;
78
79	if (inet_aton(cp, &val))
80		return (val.s_addr);
81	return (INADDR_NONE);
82}
83
84/*
85 * Check whether "cp" is a valid ascii representation
86 * of an Internet address and convert to a binary address.
87 * Returns 1 if the address is valid, 0 if not.
88 * This replaces inet_addr, the return value from which
89 * cannot distinguish between failure and a local broadcast address.
90 */
91int
92inet_aton(cp, addr)
93	register const char *cp;
94	struct in_addr *addr;
95{
96	register in_addr_t val;
97	register int base, n;
98	register char c;
99	u_int parts[4];
100	register u_int *pp = parts;
101
102	c = *cp;
103	for (;;) {
104		/*
105		 * Collect number up to ``.''.
106		 * Values are specified as for C:
107		 * 0x=hex, 0=octal, isdigit=decimal.
108		 */
109		if (!isdigit(c))
110			return (0);
111		val = 0; base = 10;
112		if (c == '0') {
113			c = *++cp;
114			if (c == 'x' || c == 'X')
115				base = 16, c = *++cp;
116			else
117				base = 8;
118		}
119		for (;;) {
120			if (isascii(c) && isdigit(c)) {
121				val = (val * base) + (c - '0');
122				c = *++cp;
123			} else if (base == 16 && isascii(c) && isxdigit(c)) {
124				val = (val << 4) |
125					(c + 10 - (islower(c) ? 'a' : 'A'));
126				c = *++cp;
127			} else
128				break;
129		}
130		if (c == '.') {
131			/*
132			 * Internet format:
133			 *	a.b.c.d
134			 *	a.b.c	(with c treated as 16 bits)
135			 *	a.b	(with b treated as 24 bits)
136			 */
137			if (pp >= parts + 3)
138				return (0);
139			*pp++ = val;
140			c = *++cp;
141		} else
142			break;
143	}
144	/*
145	 * Check for trailing characters.
146	 */
147	if (c != '\0' && (!isascii(c) || !isspace(c)))
148		return (0);
149	/*
150	 * Concoct the address according to
151	 * the number of parts specified.
152	 */
153	n = pp - parts + 1;
154	switch (n) {
155
156	case 0:
157		return (0);		/* initial nondigit */
158
159	case 1:				/* a -- 32 bits */
160		break;
161
162	case 2:				/* a.b -- 8.24 bits */
163		if ((val > 0xffffff) || (parts[0] > 0xff))
164			return (0);
165		val |= parts[0] << 24;
166		break;
167
168	case 3:				/* a.b.c -- 8.8.16 bits */
169		if ((val > 0xffff) || (parts[0] > 0xff) || (parts[1] > 0xff))
170			return (0);
171		val |= (parts[0] << 24) | (parts[1] << 16);
172		break;
173
174	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
175		if ((val > 0xff) || (parts[0] > 0xff) || (parts[1] > 0xff) || (parts[2] > 0xff))
176			return (0);
177		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
178		break;
179	}
180	if (addr)
181		addr->s_addr = htonl(val);
182	return (1);
183}
184