xref: /freebsd/lib/libc/inet/inet_pton.c (revision 55141f2c8991b2a6adbf30bb0fe3e6cbc303f06d)
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)
21 static 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 "port_before.h"
24 #include <sys/param.h>
25 #include <sys/socket.h>
26 #include <netinet/in.h>
27 #include <arpa/inet.h>
28 #include <arpa/nameser.h>
29 #include <string.h>
30 #include <errno.h>
31 #include "port_after.h"
32 
33 /*%
34  * WARNING: Don't even consider trying to compile this on a system where
35  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
36  */
37 
38 static int	inet_pton4(const char *src, u_char *dst);
39 static int	inet_pton6(const char *src, u_char *dst);
40 
41 /* int
42  * inet_pton(af, src, dst)
43  *	convert from presentation format (which usually means ASCII printable)
44  *	to network format (which is usually some kind of binary format).
45  * return:
46  *	1 if the address was valid for the specified address family
47  *	0 if the address wasn't valid (`dst' is untouched in this case)
48  *	-1 if some other error occurred (`dst' is untouched in this case, too)
49  * author:
50  *	Paul Vixie, 1996.
51  */
52 int
53 inet_pton(int af, const char * __restrict src, void * __restrict dst)
54 {
55 	switch (af) {
56 	case AF_INET:
57 		return (inet_pton4(src, dst));
58 	case AF_INET6:
59 		return (inet_pton6(src, dst));
60 	default:
61 		errno = EAFNOSUPPORT;
62 		return (-1);
63 	}
64 	/* NOTREACHED */
65 }
66 
67 /* int
68  * inet_pton4(src, dst)
69  *	like inet_aton() but without all the hexadecimal and shorthand.
70  * return:
71  *	1 if `src' is a valid dotted quad, else 0.
72  * notice:
73  *	does not touch `dst' unless it's returning 1.
74  * author:
75  *	Paul Vixie, 1996.
76  */
77 static int
78 inet_pton4(const char *src, u_char *dst)
79 {
80 	static const char digits[] = "0123456789";
81 	int saw_digit, octets, ch;
82 	u_char tmp[NS_INADDRSZ], *tp;
83 
84 	saw_digit = 0;
85 	octets = 0;
86 	*(tp = tmp) = 0;
87 	while ((ch = *src++) != '\0') {
88 		const char *pch;
89 
90 		if ((pch = strchr(digits, ch)) != NULL) {
91 			u_int new = *tp * 10 + (pch - digits);
92 
93 			if (saw_digit && *tp == 0)
94 				return (0);
95 			if (new > 255)
96 				return (0);
97 			*tp = new;
98 			if (!saw_digit) {
99 				if (++octets > 4)
100 					return (0);
101 				saw_digit = 1;
102 			}
103 		} else if (ch == '.' && saw_digit) {
104 			if (octets == 4)
105 				return (0);
106 			*++tp = 0;
107 			saw_digit = 0;
108 		} else
109 			return (0);
110 	}
111 	if (octets < 4)
112 		return (0);
113 	memcpy(dst, tmp, NS_INADDRSZ);
114 	return (1);
115 }
116 
117 /* int
118  * inet_pton6(src, dst)
119  *	convert presentation level address to network order binary form.
120  * return:
121  *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
122  * notice:
123  *	(1) does not touch `dst' unless it's returning 1.
124  *	(2) :: in a full address is silently ignored.
125  * credit:
126  *	inspired by Mark Andrews.
127  * author:
128  *	Paul Vixie, 1996.
129  */
130 static int
131 inet_pton6(const char *src, u_char *dst)
132 {
133 	static const char xdigits_l[] = "0123456789abcdef",
134 			  xdigits_u[] = "0123456789ABCDEF";
135 	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
136 	const char *xdigits, *curtok;
137 	int ch, seen_xdigits;
138 	u_int val;
139 
140 	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
141 	endp = tp + NS_IN6ADDRSZ;
142 	colonp = NULL;
143 	/* Leading :: requires some special handling. */
144 	if (*src == ':')
145 		if (*++src != ':')
146 			return (0);
147 	curtok = src;
148 	seen_xdigits = 0;
149 	val = 0;
150 	while ((ch = *src++) != '\0') {
151 		const char *pch;
152 
153 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
154 			pch = strchr((xdigits = xdigits_u), ch);
155 		if (pch != NULL) {
156 			val <<= 4;
157 			val |= (pch - xdigits);
158 			if (++seen_xdigits > 4)
159 				return (0);
160 			continue;
161 		}
162 		if (ch == ':') {
163 			curtok = src;
164 			if (!seen_xdigits) {
165 				if (colonp)
166 					return (0);
167 				colonp = tp;
168 				continue;
169 			} else if (*src == '\0') {
170 				return (0);
171 			}
172 			if (tp + NS_INT16SZ > endp)
173 				return (0);
174 			*tp++ = (u_char) (val >> 8) & 0xff;
175 			*tp++ = (u_char) val & 0xff;
176 			seen_xdigits = 0;
177 			val = 0;
178 			continue;
179 		}
180 		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
181 		    inet_pton4(curtok, tp) > 0) {
182 			tp += NS_INADDRSZ;
183 			seen_xdigits = 0;
184 			break;	/*%< '\\0' was seen by inet_pton4(). */
185 		}
186 		return (0);
187 	}
188 	if (seen_xdigits) {
189 		if (tp + NS_INT16SZ > endp)
190 			return (0);
191 		*tp++ = (u_char) (val >> 8) & 0xff;
192 		*tp++ = (u_char) val & 0xff;
193 	}
194 	if (colonp != NULL) {
195 		/*
196 		 * Since some memmove()'s erroneously fail to handle
197 		 * overlapping regions, we'll do the shift by hand.
198 		 */
199 		const int n = tp - colonp;
200 		int i;
201 
202 		if (tp == endp)
203 			return (0);
204 		for (i = 1; i <= n; i++) {
205 			endp[- i] = colonp[n - i];
206 			colonp[n - i] = 0;
207 		}
208 		tp = endp;
209 	}
210 	if (tp != endp)
211 		return (0);
212 	memcpy(dst, tmp, NS_IN6ADDRSZ);
213 	return (1);
214 }
215 
216 /*
217  * Weak aliases for applications that use certain private entry points,
218  * and fail to include <arpa/inet.h>.
219  */
220 #undef inet_pton
221 __weak_reference(__inet_pton, inet_pton);
222 
223 /*! \file */
224