xref: /openbsd-src/lib/libc/net/inet_pton.c (revision e1ef3f59d31ab6b570679ca40ea4cd3c33afa99e)
1 /*	$OpenBSD: inet_pton.c,v 1.2 1997/04/13 05:08:24 deraadt 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 #if defined(LIBC_SCCS) && !defined(lint)
20 #if 0
21 static char rcsid[] = "$From: inet_pton.c,v 8.7 1996/08/05 08:31:35 vixie Exp $";
22 #else
23 static char rcsid[] = "$OpenBSD: inet_pton.c,v 1.2 1997/04/13 05:08:24 deraadt Exp $";
24 #endif
25 #endif /* LIBC_SCCS and not lint */
26 
27 #include <sys/param.h>
28 #include <sys/types.h>
29 #include <sys/socket.h>
30 #include <netinet/in.h>
31 #include <arpa/inet.h>
32 #include <arpa/nameser.h>
33 #include <string.h>
34 #include <errno.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 
41 static int	inet_pton4 __P((const char *src, u_char *dst));
42 static int	inet_pton6 __P((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  */
55 int
56 inet_pton(af, src, dst)
57 	int af;
58 	const char *src;
59 	void *dst;
60 {
61 	switch (af) {
62 	case AF_INET:
63 		return (inet_pton4(src, dst));
64 	case AF_INET6:
65 		return (inet_pton6(src, dst));
66 	default:
67 		errno = EAFNOSUPPORT;
68 		return (-1);
69 	}
70 	/* NOTREACHED */
71 }
72 
73 /* int
74  * inet_pton4(src, dst)
75  *	like inet_aton() but without all the hexadecimal and shorthand.
76  * return:
77  *	1 if `src' is a valid dotted quad, else 0.
78  * notice:
79  *	does not touch `dst' unless it's returning 1.
80  * author:
81  *	Paul Vixie, 1996.
82  */
83 static int
84 inet_pton4(src, dst)
85 	const char *src;
86 	u_char *dst;
87 {
88 	static const char digits[] = "0123456789";
89 	int saw_digit, octets, ch;
90 	u_char tmp[INADDRSZ], *tp;
91 
92 	saw_digit = 0;
93 	octets = 0;
94 	*(tp = tmp) = 0;
95 	while ((ch = *src++) != '\0') {
96 		const char *pch;
97 
98 		if ((pch = strchr(digits, ch)) != NULL) {
99 			u_int new = *tp * 10 + (pch - digits);
100 
101 			if (new > 255)
102 				return (0);
103 			if (! saw_digit) {
104 				if (++octets > 4)
105 					return (0);
106 				saw_digit = 1;
107 			}
108 			*tp = new;
109 		} else if (ch == '.' && saw_digit) {
110 			if (octets == 4)
111 				return (0);
112 			*++tp = 0;
113 			saw_digit = 0;
114 		} else
115 			return (0);
116 	}
117 	if (octets < 4)
118 		return (0);
119 
120 	memcpy(dst, tmp, INADDRSZ);
121 	return (1);
122 }
123 
124 /* int
125  * inet_pton6(src, dst)
126  *	convert presentation level address to network order binary form.
127  * return:
128  *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
129  * notice:
130  *	(1) does not touch `dst' unless it's returning 1.
131  *	(2) :: in a full address is silently ignored.
132  * credit:
133  *	inspired by Mark Andrews.
134  * author:
135  *	Paul Vixie, 1996.
136  */
137 static int
138 inet_pton6(src, dst)
139 	const char *src;
140 	u_char *dst;
141 {
142 	static const char xdigits_l[] = "0123456789abcdef",
143 			  xdigits_u[] = "0123456789ABCDEF";
144 	u_char tmp[IN6ADDRSZ], *tp, *endp, *colonp;
145 	const char *xdigits, *curtok;
146 	int ch, saw_xdigit;
147 	u_int val;
148 
149 	memset((tp = tmp), '\0', IN6ADDRSZ);
150 	endp = tp + IN6ADDRSZ;
151 	colonp = NULL;
152 	/* Leading :: requires some special handling. */
153 	if (*src == ':')
154 		if (*++src != ':')
155 			return (0);
156 	curtok = src;
157 	saw_xdigit = 0;
158 	val = 0;
159 	while ((ch = *src++) != '\0') {
160 		const char *pch;
161 
162 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
163 			pch = strchr((xdigits = xdigits_u), ch);
164 		if (pch != NULL) {
165 			val <<= 4;
166 			val |= (pch - xdigits);
167 			if (val > 0xffff)
168 				return (0);
169 			saw_xdigit = 1;
170 			continue;
171 		}
172 		if (ch == ':') {
173 			curtok = src;
174 			if (!saw_xdigit) {
175 				if (colonp)
176 					return (0);
177 				colonp = tp;
178 				continue;
179 			}
180 			if (tp + INT16SZ > endp)
181 				return (0);
182 			*tp++ = (u_char) (val >> 8) & 0xff;
183 			*tp++ = (u_char) val & 0xff;
184 			saw_xdigit = 0;
185 			val = 0;
186 			continue;
187 		}
188 		if (ch == '.' && ((tp + INADDRSZ) <= endp) &&
189 		    inet_pton4(curtok, tp) > 0) {
190 			tp += INADDRSZ;
191 			saw_xdigit = 0;
192 			break;	/* '\0' was seen by inet_pton4(). */
193 		}
194 		return (0);
195 	}
196 	if (saw_xdigit) {
197 		if (tp + INT16SZ > endp)
198 			return (0);
199 		*tp++ = (u_char) (val >> 8) & 0xff;
200 		*tp++ = (u_char) val & 0xff;
201 	}
202 	if (colonp != NULL) {
203 		/*
204 		 * Since some memmove()'s erroneously fail to handle
205 		 * overlapping regions, we'll do the shift by hand.
206 		 */
207 		const int n = tp - colonp;
208 		int i;
209 
210 		for (i = 1; i <= n; i++) {
211 			endp[- i] = colonp[n - i];
212 			colonp[n - i] = 0;
213 		}
214 		tp = endp;
215 	}
216 	if (tp != endp)
217 		return (0);
218 	memcpy(dst, tmp, IN6ADDRSZ);
219 	return (1);
220 }
221