1/*	$NetBSD: inet_pton.c,v 1.1.1.4 2009/04/12 16:35:45 christos Exp $	*/
2
3/*
4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (c) 1996,1999 by Internet Software Consortium.
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20#include <sys/cdefs.h>
21#if defined(LIBC_SCCS) && !defined(lint)
22#if 0
23static const char rcsid[] = "Id: inet_pton.c,v 1.5 2005/07/28 06:51:47 marka Exp";
24#else
25__RCSID("$NetBSD: inet_pton.c,v 1.6 2008/06/21 20:41:48 christos Exp $");
26#endif
27#endif /* LIBC_SCCS and not lint */
28
29#include "port_before.h"
30
31#include "namespace.h"
32#include <sys/param.h>
33#include <sys/types.h>
34#include <sys/socket.h>
35#include <netinet/in.h>
36#include <arpa/inet.h>
37#include <arpa/nameser.h>
38#include <string.h>
39#include <assert.h>
40#include <ctype.h>
41#include <errno.h>
42
43#include "port_after.h"
44
45#ifdef __weak_alias
46__weak_alias(inet_pton,_inet_pton)
47#endif
48
49/*%
50 * WARNING: Don't even consider trying to compile this on a system where
51 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
52 */
53
54static int	inet_pton4(const char *src, u_char *dst, int pton);
55static int	inet_pton6(const char *src, u_char *dst);
56
57/* int
58 * inet_pton(af, src, dst)
59 *	convert from presentation format (which usually means ASCII printable)
60 *	to network format (which is usually some kind of binary format).
61 * return:
62 *	1 if the address was valid for the specified address family
63 *	0 if the address wasn't valid (`dst' is untouched in this case)
64 *	-1 if some other error occurred (`dst' is untouched in this case, too)
65 * author:
66 *	Paul Vixie, 1996.
67 */
68int
69inet_pton(int af, const char *src, void *dst)
70{
71
72	_DIAGASSERT(src != NULL);
73	_DIAGASSERT(dst != NULL);
74
75	switch (af) {
76	case AF_INET:
77		return (inet_pton4(src, dst, 1));
78	case AF_INET6:
79		return (inet_pton6(src, dst));
80	default:
81		errno = EAFNOSUPPORT;
82		return (-1);
83	}
84	/* NOTREACHED */
85}
86
87/* int
88 * inet_pton4(src, dst, pton)
89 *	when last arg is 0: inet_aton(). with hexadecimal, octal and shorthand.
90 *	when last arg is 1: inet_pton(). decimal dotted-quad only.
91 * return:
92 *	1 if `src' is a valid input, else 0.
93 * notice:
94 *	does not touch `dst' unless it's returning 1.
95 * author:
96 *	Paul Vixie, 1996.
97 */
98static int
99inet_pton4(const char *src, u_char *dst, int pton)
100{
101	u_int32_t val;
102	u_int digit, base;
103	int n;
104	unsigned char c;
105	u_int parts[4];
106	register u_int *pp = parts;
107
108	_DIAGASSERT(src != NULL);
109	_DIAGASSERT(dst != NULL);
110
111	c = *src;
112	for (;;) {
113		/*
114		 * Collect number up to ``.''.
115		 * Values are specified as for C:
116		 * 0x=hex, 0=octal, isdigit=decimal.
117		 */
118		if (!isdigit(c))
119			return (0);
120		val = 0; base = 10;
121		if (c == '0') {
122			c = *++src;
123			if (c == 'x' || c == 'X')
124				base = 16, c = *++src;
125			else if (isdigit(c) && c != '9')
126				base = 8;
127		}
128		/* inet_pton() takes decimal only */
129		if (pton && base != 10)
130			return (0);
131		for (;;) {
132			if (isdigit(c)) {
133				digit = c - '0';
134				if (digit >= base)
135					break;
136				val = (val * base) + digit;
137				c = *++src;
138			} else if (base == 16 && isxdigit(c)) {
139				digit = c + 10 - (islower(c) ? 'a' : 'A');
140				if (digit >= 16)
141					break;
142				val = (val << 4) | digit;
143				c = *++src;
144			} else
145				break;
146		}
147		if (c == '.') {
148			/*
149			 * Internet format:
150			 *	a.b.c.d
151			 *	a.b.c	(with c treated as 16 bits)
152			 *	a.b	(with b treated as 24 bits)
153			 *	a	(with a treated as 32 bits)
154			 */
155			if (pp >= parts + 3)
156				return (0);
157			*pp++ = val;
158			c = *++src;
159		} else
160			break;
161	}
162	/*
163	 * Check for trailing characters.
164	 */
165	if (c != '\0' && !isspace(c))
166		return (0);
167	/*
168	 * Concoct the address according to
169	 * the number of parts specified.
170	 */
171	n = pp - parts + 1;
172	/* inet_pton() takes dotted-quad only.  it does not take shorthand. */
173	if (pton && n != 4)
174		return (0);
175	switch (n) {
176
177	case 0:
178		return (0);		/* initial nondigit */
179
180	case 1:				/* a -- 32 bits */
181		break;
182
183	case 2:				/* a.b -- 8.24 bits */
184		if (parts[0] > 0xff || val > 0xffffff)
185			return (0);
186		val |= parts[0] << 24;
187		break;
188
189	case 3:				/* a.b.c -- 8.8.16 bits */
190		if ((parts[0] | parts[1]) > 0xff || val > 0xffff)
191			return (0);
192		val |= (parts[0] << 24) | (parts[1] << 16);
193		break;
194
195	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
196		if ((parts[0] | parts[1] | parts[2] | val) > 0xff)
197			return (0);
198		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
199		break;
200	}
201	if (dst) {
202		val = htonl(val);
203		memcpy(dst, &val, NS_INADDRSZ);
204	}
205	return (1);
206}
207
208/* int
209 * inet_pton6(src, dst)
210 *	convert presentation level address to network order binary form.
211 * return:
212 *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
213 * notice:
214 *	(1) does not touch `dst' unless it's returning 1.
215 *	(2) :: in a full address is silently ignored.
216 * credit:
217 *	inspired by Mark Andrews.
218 * author:
219 *	Paul Vixie, 1996.
220 */
221static int
222inet_pton6(const char *src, u_char *dst)
223{
224	static const char xdigits_l[] = "0123456789abcdef",
225			  xdigits_u[] = "0123456789ABCDEF";
226	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
227	const char *xdigits, *curtok;
228	int ch, seen_xdigits;
229	u_int val;
230
231	_DIAGASSERT(src != NULL);
232	_DIAGASSERT(dst != NULL);
233
234	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
235	endp = tp + NS_IN6ADDRSZ;
236	colonp = NULL;
237	/* Leading :: requires some special handling. */
238	if (*src == ':')
239		if (*++src != ':')
240			return (0);
241	curtok = src;
242	seen_xdigits = 0;
243	val = 0;
244	while ((ch = *src++) != '\0') {
245		const char *pch;
246
247		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
248			pch = strchr((xdigits = xdigits_u), ch);
249		if (pch != NULL) {
250			val <<= 4;
251			val |= (pch - xdigits);
252			if (++seen_xdigits > 4)
253				return (0);
254			continue;
255		}
256		if (ch == ':') {
257			curtok = src;
258			if (!seen_xdigits) {
259				if (colonp)
260					return (0);
261				colonp = tp;
262				continue;
263			} else if (*src == '\0')
264				return (0);
265			if (tp + NS_INT16SZ > endp)
266				return (0);
267			*tp++ = (u_char) (val >> 8) & 0xff;
268			*tp++ = (u_char) val & 0xff;
269			seen_xdigits = 0;
270			val = 0;
271			continue;
272		}
273		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
274		    inet_pton4(curtok, tp, 1) > 0) {
275			tp += NS_INADDRSZ;
276			seen_xdigits = 0;
277			break;	/*%< '\\0' was seen by inet_pton4(). */
278		}
279		return (0);
280	}
281	if (seen_xdigits) {
282		if (tp + NS_INT16SZ > endp)
283			return (0);
284		*tp++ = (u_char) (val >> 8) & 0xff;
285		*tp++ = (u_char) val & 0xff;
286	}
287	if (colonp != NULL) {
288		/*
289		 * Since some memmove()'s erroneously fail to handle
290		 * overlapping regions, we'll do the shift by hand.
291		 */
292		const int n = tp - colonp;
293		int i;
294
295		if (tp == endp)
296			return (0);
297		for (i = 1; i <= n; i++) {
298			endp[- i] = colonp[n - i];
299			colonp[n - i] = 0;
300		}
301		tp = endp;
302	}
303	if (tp != endp)
304		return (0);
305	memcpy(dst, tmp, NS_IN6ADDRSZ);
306	return (1);
307}
308
309/*! \file */
310