1 /*-
2 * Copyright (c) 2001 Charles Mott <cm@linktel.net>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: releng/8.4/sys/libkern/inet_aton.c 199651 2009-11-22 16:04:49Z attilio $");
29
30 #include <sys/param.h>
31 #include <sys/ctype.h>
32 #include <sys/limits.h>
33 #include <sys/systm.h>
34
35 #include <netinet/in.h>
36
37 int
38 inet_aton(const char *cp, struct in_addr *addr)
39 {
40 u_long parts[4];
41 in_addr_t val;
42 const char *c;
43 char *endptr;
44 int gotend, n;
45
46 c = (const char *)cp;
47 n = 0;
48
49 /*
50 * Run through the string, grabbing numbers until
51 * the end of the string, or some error
52 */
53 gotend = 0;
54 while (!gotend) {
55 unsigned long l;
56
57 l = strtoul(c, &endptr, 0);
58
59 if (l == ULONG_MAX || (l == 0 && endptr == c))
60 return (0);
61
62 val = (in_addr_t)l;
63
64 /*
65 * If the whole string is invalid, endptr will equal
66 * c.. this way we can make sure someone hasn't
67 * gone '.12' or something which would get past
68 * the next check.
69 */
70 if (endptr == c)
71 return (0);
72 parts[n] = val;
73 c = endptr;
74
75 /* Check the next character past the previous number's end */
76 switch (*c) {
77 case '.' :
78
79 /* Make sure we only do 3 dots .. */
80 if (n == 3) /* Whoops. Quit. */
81 return (0);
82 n++;
83 c++;
84 break;
85
86 case '\0':
87 gotend = 1;
88 break;
89
90 default:
91 if (isspace((unsigned char)*c)) {
92 gotend = 1;
93 break;
94 } else {
95
96 /* Invalid character, then fail. */
97 return (0);
98 }
99 }
100
101 }
102
103 /* Concoct the address according to the number of parts specified. */
104 switch (n) {
105 case 0: /* a -- 32 bits */
106
107 /*
108 * Nothing is necessary here. Overflow checking was
109 * already done in strtoul().
110 */
111 break;
112 case 1: /* a.b -- 8.24 bits */
113 if (val > 0xffffff || parts[0] > 0xff)
114 return (0);
115 val |= parts[0] << 24;
116 break;
117
118 case 2: /* a.b.c -- 8.8.16 bits */
119 if (val > 0xffff || parts[0] > 0xff || parts[1] > 0xff)
120 return (0);
121 val |= (parts[0] << 24) | (parts[1] << 16);
122 break;
123
124 case 3: /* a.b.c.d -- 8.8.8.8 bits */
125 if (val > 0xff || parts[0] > 0xff || parts[1] > 0xff ||
126 parts[2] > 0xff)
127 return (0);
128 val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
129 break;
130 }
131
132 if (addr != NULL)
133 addr->s_addr = htonl(val);
134 return (1);
135 }
136
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