1/*
2 * Copyright (C) 2004, 2005, 2007, 2013, 2014  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1996-2003  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/*! \file */
19
20#if defined(LIBC_SCCS) && !defined(lint)
21static char rcsid[] =
22	"$Id: inet_pton.c,v 1.19 2007/06/19 23:47:17 tbox Exp $";
23#endif /* LIBC_SCCS and not lint */
24
25#include <config.h>
26
27#include <errno.h>
28#include <string.h>
29
30#include <isc/net.h>
31
32/*% INT16 Size */
33#define NS_INT16SZ	 2
34/*% IPv4 Address Size */
35#define NS_INADDRSZ	 4
36/*% IPv6 Address Size */
37#define NS_IN6ADDRSZ	16
38
39/*
40 * WARNING: Don't even consider trying to compile this on a system where
41 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
42 */
43
44static int inet_pton4(const char *src, unsigned char *dst);
45static int inet_pton6(const char *src, unsigned char *dst);
46
47/*%
48 *	convert from presentation format (which usually means ASCII printable)
49 *	to network format (which is usually some kind of binary format).
50 * \return
51 *	1 if the address was valid for the specified address family
52 *	0 if the address wasn't valid (`dst' is untouched in this case)
53 *	-1 if some other error occurred (`dst' is untouched in this case, too)
54 * \author
55 *	Paul Vixie, 1996.
56 */
57int
58isc_net_pton(int af, const char *src, void *dst) {
59	switch (af) {
60	case AF_INET:
61		return (inet_pton4(src, dst));
62	case AF_INET6:
63		return (inet_pton6(src, dst));
64	default:
65		errno = EAFNOSUPPORT;
66		return (-1);
67	}
68	/* NOTREACHED */
69}
70
71/*!\fn static int inet_pton4(const char *src, unsigned char *dst)
72 * \brief
73 *	like inet_aton() but without all the hexadecimal and shorthand.
74 * \return
75 *	1 if `src' is a valid dotted quad, else 0.
76 * \note
77 *	does not touch `dst' unless it's returning 1.
78 * \author
79 *	Paul Vixie, 1996.
80 */
81static int
82inet_pton4(const char *src, unsigned char *dst) {
83	static const char digits[] = "0123456789";
84	int saw_digit, octets, ch;
85	unsigned 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			unsigned int new = *tp * 10;
95
96			new += (int)(pch - digits);
97			if (saw_digit && *tp == 0)
98				return (0);
99			if (new > 255)
100				return (0);
101			*tp = new;
102			if (!saw_digit) {
103				if (++octets > 4)
104					return (0);
105				saw_digit = 1;
106			}
107		} else if (ch == '.' && saw_digit) {
108			if (octets == 4)
109				return (0);
110			*++tp = 0;
111			saw_digit = 0;
112		} else
113			return (0);
114	}
115	if (octets < 4)
116		return (0);
117	memmove(dst, tmp, NS_INADDRSZ);
118	return (1);
119}
120
121/*%
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 * \note
126 *	(1) does not touch `dst' unless it's returning 1.
127 * \note
128 *	(2) :: in a full address is silently ignored.
129 * \author
130 *	inspired by Mark Andrews.
131 * \author
132 *	Paul Vixie, 1996.
133 */
134static int
135inet_pton6(const char *src, unsigned char *dst) {
136	static const char xdigits_l[] = "0123456789abcdef",
137			  xdigits_u[] = "0123456789ABCDEF";
138	unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
139	const char *xdigits, *curtok;
140	int ch, seen_xdigits;
141	unsigned 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			}
173			if (tp + NS_INT16SZ > endp)
174				return (0);
175			*tp++ = (unsigned char) (val >> 8) & 0xff;
176			*tp++ = (unsigned char) val & 0xff;
177			seen_xdigits = 0;
178			val = 0;
179			continue;
180		}
181		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
182		    inet_pton4(curtok, tp) > 0) {
183			tp += NS_INADDRSZ;
184			seen_xdigits = 0;
185			break;	/* '\0' was seen by inet_pton4(). */
186		}
187		return (0);
188	}
189	if (seen_xdigits) {
190		if (tp + NS_INT16SZ > endp)
191			return (0);
192		*tp++ = (unsigned char) (val >> 8) & 0xff;
193		*tp++ = (unsigned char) val & 0xff;
194	}
195	if (colonp != NULL) {
196		/*
197		 * Since some memmove()'s erroneously fail to handle
198		 * overlapping regions, we'll do the shift by hand.
199		 */
200		const int n = (int)(tp - colonp);
201		int i;
202
203		if (tp == endp)
204			return (0);
205		for (i = 1; i <= n; i++) {
206			endp[- i] = colonp[n - i];
207			colonp[n - i] = 0;
208		}
209		tp = endp;
210	}
211	if (tp != endp)
212		return (0);
213	memmove(dst, tmp, NS_IN6ADDRSZ);
214	return (1);
215}
216