xref: /freebsd/lib/libc/inet/inet_pton.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
1 /*
2  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (c) 1996,1999 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 ISC DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static const char rcsid[] = "$Id: inet_pton.c,v 1.3.18.2 2005/07/28 07:38:07 marka Exp $";
20 #endif /* LIBC_SCCS and not lint */
21 #include <sys/cdefs.h>
22 __FBSDID("$FreeBSD$");
23 
24 #include "port_before.h"
25 #include <sys/param.h>
26 #include <sys/types.h>
27 #include <sys/socket.h>
28 #include <netinet/in.h>
29 #include <arpa/inet.h>
30 #include <arpa/nameser.h>
31 #include <string.h>
32 #include <errno.h>
33 #include "port_after.h"
34 
35 /*%
36  * WARNING: Don't even consider trying to compile this on a system where
37  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
38  */
39 
40 static int	inet_pton4(const char *src, u_char *dst);
41 static int	inet_pton6(const char *src, u_char *dst);
42 
43 /* int
44  * inet_pton(af, src, dst)
45  *	convert from presentation format (which usually means ASCII printable)
46  *	to network format (which is usually some kind of binary format).
47  * return:
48  *	1 if the address was valid for the specified address family
49  *	0 if the address wasn't valid (`dst' is untouched in this case)
50  *	-1 if some other error occurred (`dst' is untouched in this case, too)
51  * author:
52  *	Paul Vixie, 1996.
53  */
54 int
55 inet_pton(int af, const char * __restrict src, void * __restrict dst)
56 {
57 	switch (af) {
58 	case AF_INET:
59 		return (inet_pton4(src, dst));
60 	case AF_INET6:
61 		return (inet_pton6(src, dst));
62 	default:
63 		errno = EAFNOSUPPORT;
64 		return (-1);
65 	}
66 	/* NOTREACHED */
67 }
68 
69 /* int
70  * inet_pton4(src, dst)
71  *	like inet_aton() but without all the hexadecimal and shorthand.
72  * return:
73  *	1 if `src' is a valid dotted quad, else 0.
74  * notice:
75  *	does not touch `dst' unless it's returning 1.
76  * author:
77  *	Paul Vixie, 1996.
78  */
79 static int
80 inet_pton4(const char *src, u_char *dst)
81 {
82 	static const char digits[] = "0123456789";
83 	int saw_digit, octets, ch;
84 	u_char tmp[NS_INADDRSZ], *tp;
85 
86 	saw_digit = 0;
87 	octets = 0;
88 	*(tp = tmp) = 0;
89 	while ((ch = *src++) != '\0') {
90 		const char *pch;
91 
92 		if ((pch = strchr(digits, ch)) != NULL) {
93 			u_int new = *tp * 10 + (pch - digits);
94 
95 			if (saw_digit && *tp == 0)
96 				return (0);
97 			if (new > 255)
98 				return (0);
99 			*tp = new;
100 			if (!saw_digit) {
101 				if (++octets > 4)
102 					return (0);
103 				saw_digit = 1;
104 			}
105 		} else if (ch == '.' && saw_digit) {
106 			if (octets == 4)
107 				return (0);
108 			*++tp = 0;
109 			saw_digit = 0;
110 		} else
111 			return (0);
112 	}
113 	if (octets < 4)
114 		return (0);
115 	memcpy(dst, tmp, NS_INADDRSZ);
116 	return (1);
117 }
118 
119 /* int
120  * inet_pton6(src, dst)
121  *	convert presentation level address to network order binary form.
122  * return:
123  *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
124  * notice:
125  *	(1) does not touch `dst' unless it's returning 1.
126  *	(2) :: in a full address is silently ignored.
127  * credit:
128  *	inspired by Mark Andrews.
129  * author:
130  *	Paul Vixie, 1996.
131  */
132 static int
133 inet_pton6(const char *src, u_char *dst)
134 {
135 	static const char xdigits_l[] = "0123456789abcdef",
136 			  xdigits_u[] = "0123456789ABCDEF";
137 	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
138 	const char *xdigits, *curtok;
139 	int ch, seen_xdigits;
140 	u_int val;
141 
142 	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
143 	endp = tp + NS_IN6ADDRSZ;
144 	colonp = NULL;
145 	/* Leading :: requires some special handling. */
146 	if (*src == ':')
147 		if (*++src != ':')
148 			return (0);
149 	curtok = src;
150 	seen_xdigits = 0;
151 	val = 0;
152 	while ((ch = *src++) != '\0') {
153 		const char *pch;
154 
155 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
156 			pch = strchr((xdigits = xdigits_u), ch);
157 		if (pch != NULL) {
158 			val <<= 4;
159 			val |= (pch - xdigits);
160 			if (++seen_xdigits > 4)
161 				return (0);
162 			continue;
163 		}
164 		if (ch == ':') {
165 			curtok = src;
166 			if (!seen_xdigits) {
167 				if (colonp)
168 					return (0);
169 				colonp = tp;
170 				continue;
171 			} else if (*src == '\0') {
172 				return (0);
173 			}
174 			if (tp + NS_INT16SZ > endp)
175 				return (0);
176 			*tp++ = (u_char) (val >> 8) & 0xff;
177 			*tp++ = (u_char) val & 0xff;
178 			seen_xdigits = 0;
179 			val = 0;
180 			continue;
181 		}
182 		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
183 		    inet_pton4(curtok, tp) > 0) {
184 			tp += NS_INADDRSZ;
185 			seen_xdigits = 0;
186 			break;	/*%< '\\0' was seen by inet_pton4(). */
187 		}
188 		return (0);
189 	}
190 	if (seen_xdigits) {
191 		if (tp + NS_INT16SZ > endp)
192 			return (0);
193 		*tp++ = (u_char) (val >> 8) & 0xff;
194 		*tp++ = (u_char) val & 0xff;
195 	}
196 	if (colonp != NULL) {
197 		/*
198 		 * Since some memmove()'s erroneously fail to handle
199 		 * overlapping regions, we'll do the shift by hand.
200 		 */
201 		const int n = tp - colonp;
202 		int i;
203 
204 		if (tp == endp)
205 			return (0);
206 		for (i = 1; i <= n; i++) {
207 			endp[- i] = colonp[n - i];
208 			colonp[n - i] = 0;
209 		}
210 		tp = endp;
211 	}
212 	if (tp != endp)
213 		return (0);
214 	memcpy(dst, tmp, NS_IN6ADDRSZ);
215 	return (1);
216 }
217 
218 /*
219  * Weak aliases for applications that use certain private entry points,
220  * and fail to include <arpa/inet.h>.
221  */
222 #undef inet_pton
223 __weak_reference(__inet_pton, inet_pton);
224 
225 /*! \file */
226