inet_aton.c revision 293896 
1/*
2 * Portions Copyright (C) 2004, 2005, 2007, 2008  Internet Systems Consortium, Inc. ("ISC")
3 * Portions Copyright (C) 1996-2001  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/*
19 * Copyright (c) 1983, 1990, 1993
20 *    The Regents of the University of California.  All rights reserved.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 *    notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 *    notice, this list of conditions and the following disclaimer in the
29 *    documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 *    must display the following acknowledgement:
32 * 	This product includes software developed by the University of
33 * 	California, Berkeley and its contributors.
34 * 4. Neither the name of the University nor the names of its contributors
35 *    may be used to endorse or promote products derived from this software
36 *    without specific prior written permission.
37 *
38 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
39 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
41 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
42 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
43 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
44 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
45 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
46 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
47 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
48 * SUCH DAMAGE.
49 */
50
51/*
52 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
53 *
54 * Permission to use, copy, modify, and distribute this software for any
55 * purpose with or without fee is hereby granted, provided that the above
56 * copyright notice and this permission notice appear in all copies, and that
57 * the name of Digital Equipment Corporation not be used in advertising or
58 * publicity pertaining to distribution of the document or software without
59 * specific, written prior permission.
60 *
61 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
62 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
63 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
64 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
65 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
66 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
67 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
68 * SOFTWARE.
69 */
70/*! \file */
71
72#if defined(LIBC_SCCS) && !defined(lint)
73static char sccsid[] = "@(#)inet_addr.c	8.1 (Berkeley) 6/17/93";
74static char rcsid[] = "$Id: inet_aton.c,v 1.23 2008/12/01 23:47:45 tbox Exp $";
75#endif /* LIBC_SCCS and not lint */
76
77#include <config.h>
78
79#include <ctype.h>
80#include <stddef.h>		/* Required for NULL. */
81
82#include <isc/types.h>
83#include <isc/net.h>
84
85/*%
86 * Check whether "cp" is a valid ascii representation
87 * of an Internet address and convert to a binary address.
88 * Returns 1 if the address is valid, 0 if not.
89 * This replaces inet_addr, the return value from which
90 * cannot distinguish between failure and a local broadcast address.
91 */
92int
93isc_net_aton(const char *cp, struct in_addr *addr) {
94	unsigned long val;
95	int base;
96	unsigned char c;
97	isc_uint8_t parts[4];
98	isc_uint8_t *pp = parts;
99	int digit;
100
101	c = *cp;
102	for (;;) {
103		/*
104		 * Collect number up to ``.''.
105		 * Values are specified as for C:
106		 * 0x=hex, 0=octal, isdigit=decimal.
107		 */
108		if (!isdigit(c & 0xff))
109			return (0);
110		val = 0; base = 10; digit = 0;
111		if (c == '0') {
112			c = *++cp;
113			if (c == 'x' || c == 'X')
114				base = 16, c = *++cp;
115			else {
116				base = 8;
117				digit = 1;
118			}
119		}
120		for (;;) {
121			/*
122			 * isascii() is valid for all integer values, and
123			 * when it is true, c is known to be in scope
124			 * for isdigit().  No cast necessary.  Similar
125			 * comment applies for later ctype uses.
126			 */
127			if (isascii(c) && isdigit(c)) {
128				if (base == 8 && (c == '8' || c == '9'))
129					return (0);
130				val = (val * base) + (c - '0');
131				c = *++cp;
132				digit = 1;
133			} else if (base == 16 && isascii(c) && isxdigit(c)) {
134				val = (val << 4) |
135					(c + 10 - (islower(c) ? 'a' : 'A'));
136				c = *++cp;
137				digit = 1;
138			} else
139				break;
140		}
141		if (c == '.') {
142			/*
143			 * Internet format:
144			 *	a.b.c.d
145			 *	a.b.c	(with c treated as 16 bits)
146			 *	a.b	(with b treated as 24 bits)
147			 */
148			if (pp >= parts + 3 || val > 0xffU)
149				return (0);
150			*pp++ = (isc_uint8_t)val;
151			c = *++cp;
152		} else
153			break;
154	}
155	/*
156	 * Check for trailing characters.
157	 */
158	if (c != '\0' && (!isascii(c) || !isspace(c)))
159		return (0);
160	/*
161	 * Did we get a valid digit?
162	 */
163	if (!digit)
164		return (0);
165	/*
166	 * Concoct the address according to
167	 * the number of parts specified.
168	 */
169	switch (pp - parts + 1) {
170	case 1:				/* a -- 32 bits */
171		break;
172
173	case 2:				/* a.b -- 8.24 bits */
174		if (val > 0xffffffU)
175			return (0);
176		val |= parts[0] << 24;
177		break;
178
179	case 3:				/* a.b.c -- 8.8.16 bits */
180		if (val > 0xffffU)
181			return (0);
182		val |= (parts[0] << 24) | (parts[1] << 16);
183		break;
184
185	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
186		if (val > 0xffU)
187			return (0);
188		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
189		break;
190	}
191	if (addr != NULL)
192		addr->s_addr = htonl(val);
193
194	return (1);
195}
196