1/*	$OpenBSD: inet_pton.c,v 1.8 2010/05/06 15:47:14 claudio Exp $	*/
2
3/* Copyright (c) 1996 by Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
10 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
11 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
12 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
13 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
14 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
15 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
16 * SOFTWARE.
17 */
18
19#include <sys/param.h>
20#include <sys/types.h>
21#include <sys/socket.h>
22#include <netinet/in.h>
23#include <arpa/inet.h>
24#include <arpa/nameser.h>
25#include <string.h>
26#include <errno.h>
27
28/*
29 * WARNING: Don't even consider trying to compile this on a system where
30 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
31 */
32
33static int	inet_pton4(const char *src, u_char *dst);
34static int	inet_pton6(const char *src, u_char *dst);
35
36/* int
37 * inet_pton(af, src, dst)
38 *	convert from presentation format (which usually means ASCII printable)
39 *	to network format (which is usually some kind of binary format).
40 * return:
41 *	1 if the address was valid for the specified address family
42 *	0 if the address wasn't valid (`dst' is untouched in this case)
43 *	-1 if some other error occurred (`dst' is untouched in this case, too)
44 * author:
45 *	Paul Vixie, 1996.
46 */
47int
48inet_pton(int af, const char *src, void *dst)
49{
50	switch (af) {
51	case AF_INET:
52		return (inet_pton4(src, dst));
53	case AF_INET6:
54		return (inet_pton6(src, dst));
55	default:
56		errno = EAFNOSUPPORT;
57		return (-1);
58	}
59	/* NOTREACHED */
60}
61
62/* int
63 * inet_pton4(src, dst)
64 *	like inet_aton() but without all the hexadecimal and shorthand.
65 * return:
66 *	1 if `src' is a valid dotted quad, else 0.
67 * notice:
68 *	does not touch `dst' unless it's returning 1.
69 * author:
70 *	Paul Vixie, 1996.
71 */
72static int
73inet_pton4(const char *src, u_char *dst)
74{
75	static const char digits[] = "0123456789";
76	int saw_digit, octets, ch;
77	u_char tmp[INADDRSZ], *tp;
78
79	saw_digit = 0;
80	octets = 0;
81	*(tp = tmp) = 0;
82	while ((ch = *src++) != '\0') {
83		const char *pch;
84
85		if ((pch = strchr(digits, ch)) != NULL) {
86			u_int new = *tp * 10 + (pch - digits);
87
88			if (new > 255)
89				return (0);
90			if (! saw_digit) {
91				if (++octets > 4)
92					return (0);
93				saw_digit = 1;
94			}
95			*tp = new;
96		} else if (ch == '.' && saw_digit) {
97			if (octets == 4)
98				return (0);
99			*++tp = 0;
100			saw_digit = 0;
101		} else
102			return (0);
103	}
104	if (octets < 4)
105		return (0);
106
107	memcpy(dst, tmp, INADDRSZ);
108	return (1);
109}
110
111/* int
112 * inet_pton6(src, dst)
113 *	convert presentation level address to network order binary form.
114 * return:
115 *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
116 * notice:
117 *	does not touch `dst' unless it's returning 1.
118 * credit:
119 *	inspired by Mark Andrews.
120 * author:
121 *	Paul Vixie, 1996.
122 */
123static int
124inet_pton6(const char *src, u_char *dst)
125{
126	static const char xdigits_l[] = "0123456789abcdef",
127			  xdigits_u[] = "0123456789ABCDEF";
128	u_char tmp[IN6ADDRSZ], *tp, *endp, *colonp;
129	const char *xdigits, *curtok;
130	int ch, saw_xdigit, count_xdigit;
131	u_int val;
132
133	memset((tp = tmp), '\0', IN6ADDRSZ);
134	endp = tp + IN6ADDRSZ;
135	colonp = NULL;
136	/* Leading :: requires some special handling. */
137	if (*src == ':')
138		if (*++src != ':')
139			return (0);
140	curtok = src;
141	saw_xdigit = count_xdigit = 0;
142	val = 0;
143	while ((ch = *src++) != '\0') {
144		const char *pch;
145
146		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
147			pch = strchr((xdigits = xdigits_u), ch);
148		if (pch != NULL) {
149			if (count_xdigit >= 4)
150				return (0);
151			val <<= 4;
152			val |= (pch - xdigits);
153			if (val > 0xffff)
154				return (0);
155			saw_xdigit = 1;
156			count_xdigit++;
157			continue;
158		}
159		if (ch == ':') {
160			curtok = src;
161			if (!saw_xdigit) {
162				if (colonp)
163					return (0);
164				colonp = tp;
165				continue;
166			} else if (*src == '\0') {
167				return (0);
168			}
169			if (tp + INT16SZ > endp)
170				return (0);
171			*tp++ = (u_char) (val >> 8) & 0xff;
172			*tp++ = (u_char) val & 0xff;
173			saw_xdigit = 0;
174			count_xdigit = 0;
175			val = 0;
176			continue;
177		}
178		if (ch == '.' && ((tp + INADDRSZ) <= endp) &&
179		    inet_pton4(curtok, tp) > 0) {
180			tp += INADDRSZ;
181			saw_xdigit = 0;
182			count_xdigit = 0;
183			break;	/* '\0' was seen by inet_pton4(). */
184		}
185		return (0);
186	}
187	if (saw_xdigit) {
188		if (tp + INT16SZ > endp)
189			return (0);
190		*tp++ = (u_char) (val >> 8) & 0xff;
191		*tp++ = (u_char) val & 0xff;
192	}
193	if (colonp != NULL) {
194		/*
195		 * Since some memmove()'s erroneously fail to handle
196		 * overlapping regions, we'll do the shift by hand.
197		 */
198		const int n = tp - colonp;
199		int i;
200
201		if (tp == endp)
202			return (0);
203		for (i = 1; i <= n; i++) {
204			endp[- i] = colonp[n - i];
205			colonp[n - i] = 0;
206		}
207		tp = endp;
208	}
209	if (tp != endp)
210		return (0);
211	memcpy(dst, tmp, IN6ADDRSZ);
212	return (1);
213}
214