xref: /openbsd/lib/libc/net/inet_addr.c (revision 91f110e0)
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  */
64 in_addr_t
65 inet_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  */
81 int
82 inet_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