inet_addr.c revision 1.10 
1/*	$OpenBSD: inet_addr.c,v 1.10 2013/11/24 23:51:28 deraadt 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#include <sys/types.h>
55#include <sys/param.h>
56#include <netinet/in.h>
57#include <arpa/inet.h>
58#include <ctype.h>
59
60/*
61 * Ascii internet address interpretation routine.
62 * The value returned is in network order.
63 */
64in_addr_t
65inet_addr(const char *cp)
66{
67	struct in_addr val;
68
69	if (inet_aton(cp, &val))
70		return (val.s_addr);
71	return (INADDR_NONE);
72}
73
74/*
75 * Check whether "cp" is a valid ascii representation
76 * of an Internet address and convert to a binary address.
77 * Returns 1 if the address is valid, 0 if not.
78 * This replaces inet_addr, the return value from which
79 * cannot distinguish between failure and a local broadcast address.
80 */
81int
82inet_aton(const char *cp, struct in_addr *addr)
83{
84	in_addr_t val;
85	int base, n;
86	char c;
87	u_int parts[4];
88	u_int *pp = parts;
89
90	c = *cp;
91	for (;;) {
92		/*
93		 * Collect number up to ``.''.
94		 * Values are specified as for C:
95		 * 0x=hex, 0=octal, isdigit=decimal.
96		 */
97		if (!isdigit((unsigned char)c))
98			return (0);
99		val = 0; base = 10;
100		if (c == '0') {
101			c = *++cp;
102			if (c == 'x' || c == 'X')
103				base = 16, c = *++cp;
104			else
105				base = 8;
106		}
107		for (;;) {
108			if (isascii((unsigned char)c) &&
109			    isdigit((unsigned char)c)) {
110				val = (val * base) + (c - '0');
111				c = *++cp;
112			} else if (base == 16 &&
113			    isascii((unsigned char)c) &&
114			    isxdigit((unsigned char)c)) {
115				val = (val << 4) |
116				    (c + 10 - (islower((unsigned char)c) ? 'a' : 'A'));
117				c = *++cp;
118			} else
119				break;
120		}
121		if (c == '.') {
122			/*
123			 * Internet format:
124			 *	a.b.c.d
125			 *	a.b.c	(with c treated as 16 bits)
126			 *	a.b	(with b treated as 24 bits)
127			 */
128			if (pp >= parts + 3)
129				return (0);
130			*pp++ = val;
131			c = *++cp;
132		} else
133			break;
134	}
135	/*
136	 * Check for trailing characters.
137	 */
138	if (c != '\0' &&
139	    (!isascii((unsigned char)c) || !isspace((unsigned char)c)))
140		return (0);
141	/*
142	 * Concoct the address according to
143	 * the number of parts specified.
144	 */
145	n = pp - parts + 1;
146	switch (n) {
147
148	case 0:
149		return (0);		/* initial nondigit */
150
151	case 1:				/* a -- 32 bits */
152		break;
153
154	case 2:				/* a.b -- 8.24 bits */
155		if ((val > 0xffffff) || (parts[0] > 0xff))
156			return (0);
157		val |= parts[0] << 24;
158		break;
159
160	case 3:				/* a.b.c -- 8.8.16 bits */
161		if ((val > 0xffff) || (parts[0] > 0xff) || (parts[1] > 0xff))
162			return (0);
163		val |= (parts[0] << 24) | (parts[1] << 16);
164		break;
165
166	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
167		if ((val > 0xff) || (parts[0] > 0xff) || (parts[1] > 0xff) || (parts[2] > 0xff))
168			return (0);
169		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
170		break;
171	}
172	if (addr)
173		addr->s_addr = htonl(val);
174	return (1);
175}
176