1 /* $OpenBSD: inet_addr.c,v 1.9 2005/08/06 20:30:03 espie 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 * Check whether "cp" is a valid ascii representation
62 * of an Internet address and convert to a binary address.
63 * Returns 1 if the address is valid, 0 if not.
64 * This replaces inet_addr, the return value from which
65 * cannot distinguish between failure and a local broadcast address.
66 */
67 int
inet_aton(const char * cp,struct in_addr * addr)68 inet_aton(const char *cp, struct in_addr *addr)
69 {
70 in_addr_t val;
71 int base, n;
72 char c;
73 u_int parts[4];
74 u_int *pp = parts;
75
76 c = *cp;
77 for (;;) {
78 /*
79 * Collect number up to ``.''.
80 * Values are specified as for C:
81 * 0x=hex, 0=octal, isdigit=decimal.
82 */
83 if (!isdigit(c))
84 return (0);
85 val = 0; base = 10;
86 if (c == '0') {
87 c = *++cp;
88 if (c == 'x' || c == 'X')
89 base = 16, c = *++cp;
90 else
91 base = 8;
92 }
93 for (;;) {
94 if (isascii(c) && isdigit(c)) {
95 val = (val * base) + (c - '0');
96 c = *++cp;
97 } else if (base == 16 && isascii(c) && isxdigit(c)) {
98 val = (val << 4) |
99 (c + 10 - (islower(c) ? 'a' : 'A'));
100 c = *++cp;
101 } else
102 break;
103 }
104 if (c == '.') {
105 /*
106 * Internet format:
107 * a.b.c.d
108 * a.b.c (with c treated as 16 bits)
109 * a.b (with b treated as 24 bits)
110 */
111 if (pp >= parts + 3)
112 return (0);
113 *pp++ = val;
114 c = *++cp;
115 } else
116 break;
117 }
118 /*
119 * Check for trailing characters.
120 */
121 if (c != '\0' && (!isascii(c) || !isspace(c)))
122 return (0);
123 /*
124 * Concoct the address according to
125 * the number of parts specified.
126 */
127 n = pp - parts + 1;
128 switch (n) {
129
130 case 0:
131 return (0); /* initial nondigit */
132
133 case 1: /* a -- 32 bits */
134 break;
135
136 case 2: /* a.b -- 8.24 bits */
137 if ((val > 0xffffff) || (parts[0] > 0xff))
138 return (0);
139 val |= parts[0] << 24;
140 break;
141
142 case 3: /* a.b.c -- 8.8.16 bits */
143 if ((val > 0xffff) || (parts[0] > 0xff) || (parts[1] > 0xff))
144 return (0);
145 val |= (parts[0] << 24) | (parts[1] << 16);
146 break;
147
148 case 4: /* a.b.c.d -- 8.8.8.8 bits */
149 if ((val > 0xff) || (parts[0] > 0xff) || (parts[1] > 0xff) || (parts[2] > 0xff))
150 return (0);
151 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
152 break;
153 }
154 if (addr)
155 addr->s_addr = htonl(val);
156 return (1);
157 }
158