inet_addr.c revision 1.1 
1/*	$NetBSD: inet_addr.c,v 1.5 1995/02/25 06:20:41 cgd Exp $	*/
2
3/*
4 * Copyright (c) 1983, 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#if defined(LIBC_SCCS) && !defined(lint)
37#if 0
38static char sccsid[] = "@(#)inet_addr.c	8.1 (Berkeley) 6/17/93";
39#else
40static char rcsid[] = "$NetBSD: inet_addr.c,v 1.5 1995/02/25 06:20:41 cgd Exp $";
41#endif
42#endif /* LIBC_SCCS and not lint */
43
44#include <sys/param.h>
45#include <netinet/in.h>
46#include <arpa/inet.h>
47#include <ctype.h>
48
49/*
50 * Ascii internet address interpretation routine.
51 * The value returned is in network order.
52 */
53u_long
54inet_addr(cp)
55	register const char *cp;
56{
57	struct in_addr val;
58
59	if (inet_aton(cp, &val))
60		return (val.s_addr);
61	return (INADDR_NONE);
62}
63
64/*
65 * Check whether "cp" is a valid ascii representation
66 * of an Internet address and convert to a binary address.
67 * Returns 1 if the address is valid, 0 if not.
68 * This replaces inet_addr, the return value from which
69 * cannot distinguish between failure and a local broadcast address.
70 */
71int
72inet_aton(cp, addr)
73	register const char *cp;
74	struct in_addr *addr;
75{
76	register u_long val;
77	register int base, n;
78	register char c;
79	u_int parts[4];
80	register u_int *pp = parts;
81
82	for (;;) {
83		/*
84		 * Collect number up to ``.''.
85		 * Values are specified as for C:
86		 * 0x=hex, 0=octal, other=decimal.
87		 */
88		val = 0; base = 10;
89		if (*cp == '0') {
90			if (*++cp == 'x' || *cp == 'X')
91				base = 16, cp++;
92			else
93				base = 8;
94		}
95		while ((c = *cp) != '\0') {
96			if (isascii(c) && isdigit(c)) {
97				val = (val * base) + (c - '0');
98				cp++;
99				continue;
100			}
101			if (base == 16 && isascii(c) && isxdigit(c)) {
102				val = (val << 4) +
103					(c + 10 - (islower(c) ? 'a' : 'A'));
104				cp++;
105				continue;
106			}
107			break;
108		}
109		if (*cp == '.') {
110			/*
111			 * Internet format:
112			 *	a.b.c.d
113			 *	a.b.c	(with c treated as 16-bits)
114			 *	a.b	(with b treated as 24 bits)
115			 */
116			if (pp >= parts + 3 || val > 0xff)
117				return (0);
118			*pp++ = val, cp++;
119		} else
120			break;
121	}
122	/*
123	 * Check for trailing characters.
124	 */
125	if (*cp && (!isascii(*cp) || !isspace(*cp)))
126		return (0);
127	/*
128	 * Concoct the address according to
129	 * the number of parts specified.
130	 */
131	n = pp - parts + 1;
132	switch (n) {
133
134	case 1:				/* a -- 32 bits */
135		break;
136
137	case 2:				/* a.b -- 8.24 bits */
138		if (val > 0xffffff)
139			return (0);
140		val |= parts[0] << 24;
141		break;
142
143	case 3:				/* a.b.c -- 8.8.16 bits */
144		if (val > 0xffff)
145			return (0);
146		val |= (parts[0] << 24) | (parts[1] << 16);
147		break;
148
149	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
150		if (val > 0xff)
151			return (0);
152		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
153		break;
154	}
155	if (addr)
156		addr->s_addr = htonl(val);
157	return (1);
158}
159