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("$FreeBSD$");
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
37int
38inet_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
137