inet_aton.c revision 323121 
1/*	$OpenBSD: inet_addr.c,v 1.9 2005/08/06 20:30:03 espie Exp $	*/
2
3/*
4 * Copyright (c) 1983, 1990, 1993
5 *    The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 * -
31 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
32 *
33 * Permission to use, copy, modify, and distribute this software for any
34 * purpose with or without fee is hereby granted, provided that the above
35 * copyright notice and this permission notice appear in all copies, and that
36 * the name of Digital Equipment Corporation not be used in advertising or
37 * publicity pertaining to distribution of the document or software without
38 * specific, written prior permission.
39 *
40 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
41 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
42 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
43 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
44 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
45 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
46 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
47 * SOFTWARE.
48 * -
49 * --Copyright--
50 */
51
52/* OPENBSD ORIGINAL: lib/libc/net/inet_addr.c */
53
54#include "includes.h"
55
56#if !defined(HAVE_INET_ATON)
57
58#include <sys/types.h>
59#include <sys/param.h>
60#include <netinet/in.h>
61#include <arpa/inet.h>
62#include <ctype.h>
63
64#if 0
65/*
66 * Ascii internet address interpretation routine.
67 * The value returned is in network order.
68 */
69in_addr_t
70inet_addr(const char *cp)
71{
72	struct in_addr val;
73
74	if (inet_aton(cp, &val))
75		return (val.s_addr);
76	return (INADDR_NONE);
77}
78#endif
79
80/*
81 * Check whether "cp" is a valid ascii representation
82 * of an Internet address and convert to a binary address.
83 * Returns 1 if the address is valid, 0 if not.
84 * This replaces inet_addr, the return value from which
85 * cannot distinguish between failure and a local broadcast address.
86 */
87int
88inet_aton(const char *cp, struct in_addr *addr)
89{
90	u_int32_t val;
91	int base, n;
92	char c;
93	u_int parts[4];
94	u_int *pp = parts;
95
96	c = *cp;
97	for (;;) {
98		/*
99		 * Collect number up to ``.''.
100		 * Values are specified as for C:
101		 * 0x=hex, 0=octal, isdigit=decimal.
102		 */
103		if (!isdigit(c))
104			return (0);
105		val = 0; base = 10;
106		if (c == '0') {
107			c = *++cp;
108			if (c == 'x' || c == 'X')
109				base = 16, c = *++cp;
110			else
111				base = 8;
112		}
113		for (;;) {
114			if (isascii(c) && isdigit(c)) {
115				val = (val * base) + (c - '0');
116				c = *++cp;
117			} else if (base == 16 && isascii(c) && isxdigit(c)) {
118				val = (val << 4) |
119					(c + 10 - (islower(c) ? 'a' : 'A'));
120				c = *++cp;
121			} else
122				break;
123		}
124		if (c == '.') {
125			/*
126			 * Internet format:
127			 *	a.b.c.d
128			 *	a.b.c	(with c treated as 16 bits)
129			 *	a.b	(with b treated as 24 bits)
130			 */
131			if (pp >= parts + 3)
132				return (0);
133			*pp++ = val;
134			c = *++cp;
135		} else
136			break;
137	}
138	/*
139	 * Check for trailing characters.
140	 */
141	if (c != '\0' && (!isascii(c) || !isspace(c)))
142		return (0);
143	/*
144	 * Concoct the address according to
145	 * the number of parts specified.
146	 */
147	n = pp - parts + 1;
148	switch (n) {
149
150	case 0:
151		return (0);		/* initial nondigit */
152
153	case 1:				/* a -- 32 bits */
154		break;
155
156	case 2:				/* a.b -- 8.24 bits */
157		if ((val > 0xffffff) || (parts[0] > 0xff))
158			return (0);
159		val |= parts[0] << 24;
160		break;
161
162	case 3:				/* a.b.c -- 8.8.16 bits */
163		if ((val > 0xffff) || (parts[0] > 0xff) || (parts[1] > 0xff))
164			return (0);
165		val |= (parts[0] << 24) | (parts[1] << 16);
166		break;
167
168	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
169		if ((val > 0xff) || (parts[0] > 0xff) || (parts[1] > 0xff) || (parts[2] > 0xff))
170			return (0);
171		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
172		break;
173	}
174	if (addr)
175		addr->s_addr = htonl(val);
176	return (1);
177}
178
179#endif /* !defined(HAVE_INET_ATON) */
180