1/*-
2 * SPDX-License-Identifier: ISC
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#if defined(LIBC_SCCS) && !defined(lint)
21static const char rcsid[] = "$Id: inet_pton.c,v 1.5 2005/07/28 06:51:47 marka Exp $";
22#endif /* LIBC_SCCS and not lint */
23#include <sys/cdefs.h>
24__FBSDID("$FreeBSD$");
25
26#include "port_before.h"
27#include <sys/param.h>
28#include <sys/socket.h>
29#include <netinet/in.h>
30#include <arpa/inet.h>
31#include <arpa/nameser.h>
32#include <string.h>
33#include <errno.h>
34#include "port_after.h"
35
36/*%
37 * WARNING: Don't even consider trying to compile this on a system where
38 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
39 */
40
41static int	inet_pton4(const char *src, u_char *dst);
42static int	inet_pton6(const char *src, u_char *dst);
43
44/* int
45 * inet_pton(af, src, dst)
46 *	convert from presentation format (which usually means ASCII printable)
47 *	to network format (which is usually some kind of binary format).
48 * return:
49 *	1 if the address was valid for the specified address family
50 *	0 if the address wasn't valid (`dst' is untouched in this case)
51 *	-1 if some other error occurred (`dst' is untouched in this case, too)
52 * author:
53 *	Paul Vixie, 1996.
54 */
55int
56inet_pton(int af, const char * __restrict src, void * __restrict dst)
57{
58	switch (af) {
59	case AF_INET:
60		return (inet_pton4(src, dst));
61	case AF_INET6:
62		return (inet_pton6(src, dst));
63	default:
64		errno = EAFNOSUPPORT;
65		return (-1);
66	}
67	/* NOTREACHED */
68}
69
70/* int
71 * inet_pton4(src, dst)
72 *	like inet_aton() but without all the hexadecimal and shorthand.
73 * return:
74 *	1 if `src' is a valid dotted quad, else 0.
75 * notice:
76 *	does not touch `dst' unless it's returning 1.
77 * author:
78 *	Paul Vixie, 1996.
79 */
80static int
81inet_pton4(const char *src, u_char *dst)
82{
83	static const char digits[] = "0123456789";
84	int saw_digit, octets, ch;
85	u_char tmp[NS_INADDRSZ], *tp;
86
87	saw_digit = 0;
88	octets = 0;
89	*(tp = tmp) = 0;
90	while ((ch = *src++) != '\0') {
91		const char *pch;
92
93		if ((pch = strchr(digits, ch)) != NULL) {
94			u_int new = *tp * 10 + (pch - digits);
95
96			if (saw_digit && *tp == 0)
97				return (0);
98			if (new > 255)
99				return (0);
100			*tp = new;
101			if (!saw_digit) {
102				if (++octets > 4)
103					return (0);
104				saw_digit = 1;
105			}
106		} else if (ch == '.' && saw_digit) {
107			if (octets == 4)
108				return (0);
109			*++tp = 0;
110			saw_digit = 0;
111		} else
112			return (0);
113	}
114	if (octets < 4)
115		return (0);
116	memcpy(dst, tmp, NS_INADDRSZ);
117	return (1);
118}
119
120/* int
121 * inet_pton6(src, dst)
122 *	convert presentation level address to network order binary form.
123 * return:
124 *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
125 * notice:
126 *	(1) does not touch `dst' unless it's returning 1.
127 *	(2) :: in a full address is silently ignored.
128 * credit:
129 *	inspired by Mark Andrews.
130 * author:
131 *	Paul Vixie, 1996.
132 */
133static int
134inet_pton6(const char *src, u_char *dst)
135{
136	static const char xdigits_l[] = "0123456789abcdef",
137			  xdigits_u[] = "0123456789ABCDEF";
138	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
139	const char *xdigits, *curtok;
140	int ch, seen_xdigits;
141	u_int val;
142
143	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
144	endp = tp + NS_IN6ADDRSZ;
145	colonp = NULL;
146	/* Leading :: requires some special handling. */
147	if (*src == ':')
148		if (*++src != ':')
149			return (0);
150	curtok = src;
151	seen_xdigits = 0;
152	val = 0;
153	while ((ch = *src++) != '\0') {
154		const char *pch;
155
156		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
157			pch = strchr((xdigits = xdigits_u), ch);
158		if (pch != NULL) {
159			val <<= 4;
160			val |= (pch - xdigits);
161			if (++seen_xdigits > 4)
162				return (0);
163			continue;
164		}
165		if (ch == ':') {
166			curtok = src;
167			if (!seen_xdigits) {
168				if (colonp)
169					return (0);
170				colonp = tp;
171				continue;
172			} else if (*src == '\0') {
173				return (0);
174			}
175			if (tp + NS_INT16SZ > endp)
176				return (0);
177			*tp++ = (u_char) (val >> 8) & 0xff;
178			*tp++ = (u_char) val & 0xff;
179			seen_xdigits = 0;
180			val = 0;
181			continue;
182		}
183		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
184		    inet_pton4(curtok, tp) > 0) {
185			tp += NS_INADDRSZ;
186			seen_xdigits = 0;
187			break;	/*%< '\\0' was seen by inet_pton4(). */
188		}
189		return (0);
190	}
191	if (seen_xdigits) {
192		if (tp + NS_INT16SZ > endp)
193			return (0);
194		*tp++ = (u_char) (val >> 8) & 0xff;
195		*tp++ = (u_char) val & 0xff;
196	}
197	if (colonp != NULL) {
198		/*
199		 * Since some memmove()'s erroneously fail to handle
200		 * overlapping regions, we'll do the shift by hand.
201		 */
202		const int n = tp - colonp;
203		int i;
204
205		if (tp == endp)
206			return (0);
207		for (i = 1; i <= n; i++) {
208			endp[- i] = colonp[n - i];
209			colonp[n - i] = 0;
210		}
211		tp = endp;
212	}
213	if (tp != endp)
214		return (0);
215	memcpy(dst, tmp, NS_IN6ADDRSZ);
216	return (1);
217}
218
219/*
220 * Weak aliases for applications that use certain private entry points,
221 * and fail to include <arpa/inet.h>.
222 */
223#undef inet_pton
224__weak_reference(__inet_pton, inet_pton);
225
226/*! \file */
227