inet_addr.c revision 1.5
1/*	$OpenBSD: inet_addr.c,v 1.5 1997/04/05 21:13:10 millert 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. All advertising materials mentioning features or use of this software
18 *    must display the following acknowledgement:
19 * 	This product includes software developed by the University of
20 * 	California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 *    may be used to endorse or promote products derived from this software
23 *    without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 * -
37 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
38 *
39 * Permission to use, copy, modify, and distribute this software for any
40 * purpose with or without fee is hereby granted, provided that the above
41 * copyright notice and this permission notice appear in all copies, and that
42 * the name of Digital Equipment Corporation not be used in advertising or
43 * publicity pertaining to distribution of the document or software without
44 * specific, written prior permission.
45 *
46 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
47 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
48 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
49 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
50 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
51 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
52 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
53 * SOFTWARE.
54 * -
55 * --Copyright--
56 */
57
58#if defined(LIBC_SCCS) && !defined(lint)
59#if 0
60static char sccsid[] = "@(#)inet_addr.c	8.1 (Berkeley) 6/17/93";
61static char rcsid[] = "$From: inet_addr.c,v 8.5 1996/08/05 08:31:35 vixie Exp $";
62#else
63static char rcsid[] = "$OpenBSD: inet_addr.c,v 1.5 1997/04/05 21:13:10 millert Exp $";
64#endif
65#endif /* LIBC_SCCS and not lint */
66
67#include <sys/types.h>
68#include <sys/param.h>
69#include <netinet/in.h>
70#include <arpa/inet.h>
71#include <ctype.h>
72
73/*
74 * Ascii internet address interpretation routine.
75 * The value returned is in network order.
76 */
77in_addr_t
78inet_addr(cp)
79	register const char *cp;
80{
81	struct in_addr val;
82
83	if (inet_aton(cp, &val))
84		return (val.s_addr);
85	return (INADDR_NONE);
86}
87
88/*
89 * Check whether "cp" is a valid ascii representation
90 * of an Internet address and convert to a binary address.
91 * Returns 1 if the address is valid, 0 if not.
92 * This replaces inet_addr, the return value from which
93 * cannot distinguish between failure and a local broadcast address.
94 */
95int
96inet_aton(cp, addr)
97	register const char *cp;
98	struct in_addr *addr;
99{
100	register in_addr_t val;
101	register int base, n;
102	register char c;
103	u_int parts[4];
104	register u_int *pp = parts;
105
106	c = *cp;
107	for (;;) {
108		/*
109		 * Collect number up to ``.''.
110		 * Values are specified as for C:
111		 * 0x=hex, 0=octal, isdigit=decimal.
112		 */
113		if (!isdigit(c))
114			return (0);
115		val = 0; base = 10;
116		if (c == '0') {
117			c = *++cp;
118			if (c == 'x' || c == 'X')
119				base = 16, c = *++cp;
120			else
121				base = 8;
122		}
123		for (;;) {
124			if (isascii(c) && isdigit(c)) {
125				val = (val * base) + (c - '0');
126				c = *++cp;
127			} else if (base == 16 && isascii(c) && isxdigit(c)) {
128				val = (val << 4) |
129					(c + 10 - (islower(c) ? 'a' : 'A'));
130				c = *++cp;
131			} else
132				break;
133		}
134		if (c == '.') {
135			/*
136			 * Internet format:
137			 *	a.b.c.d
138			 *	a.b.c	(with c treated as 16 bits)
139			 *	a.b	(with b treated as 24 bits)
140			 */
141			if (pp >= parts + 3)
142				return (0);
143			*pp++ = val;
144			c = *++cp;
145		} else
146			break;
147	}
148	/*
149	 * Check for trailing characters.
150	 */
151	if (c != '\0' && (!isascii(c) || !isspace(c)))
152		return (0);
153	/*
154	 * Concoct the address according to
155	 * the number of parts specified.
156	 */
157	n = pp - parts + 1;
158	switch (n) {
159
160	case 0:
161		return (0);		/* initial nondigit */
162
163	case 1:				/* a -- 32 bits */
164		break;
165
166	case 2:				/* a.b -- 8.24 bits */
167		if (val > 0xffffff)
168			return (0);
169		val |= parts[0] << 24;
170		break;
171
172	case 3:				/* a.b.c -- 8.8.16 bits */
173		if (val > 0xffff)
174			return (0);
175		val |= (parts[0] << 24) | (parts[1] << 16);
176		break;
177
178	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
179		if (val > 0xff)
180			return (0);
181		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
182		break;
183	}
184	if (addr)
185		addr->s_addr = htonl(val);
186	return (1);
187}
188