xref: /freebsd/lib/libc/inet/inet_pton.c (revision 61ba55bcf70f2340f9c943c9571113b3fd8eda69)
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 <sys/cdefs.h>
24 #include "port_before.h"
25 #include <sys/param.h>
26 #include <sys/socket.h>
27 #include <netinet/in.h>
28 #include <arpa/inet.h>
29 #include <arpa/nameser.h>
30 #include <string.h>
31 #include <errno.h>
32 #include "port_after.h"
33 
34 /*%
35  * WARNING: Don't even consider trying to compile this on a system where
36  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
37  */
38 
39 static int	inet_pton4(const char *src, u_char *dst);
40 static int	inet_pton6(const char *src, u_char *dst);
41 
42 /* int
43  * inet_pton(af, src, dst)
44  *	convert from presentation format (which usually means ASCII printable)
45  *	to network format (which is usually some kind of binary format).
46  * return:
47  *	1 if the address was valid for the specified address family
48  *	0 if the address wasn't valid (`dst' is untouched in this case)
49  *	-1 if some other error occurred (`dst' is untouched in this case, too)
50  * author:
51  *	Paul Vixie, 1996.
52  */
53 int
54 inet_pton(int af, const char * __restrict src, void * __restrict dst)
55 {
56 	switch (af) {
57 	case AF_INET:
58 		return (inet_pton4(src, dst));
59 	case AF_INET6:
60 		return (inet_pton6(src, dst));
61 	default:
62 		errno = EAFNOSUPPORT;
63 		return (-1);
64 	}
65 	/* NOTREACHED */
66 }
67 
68 /* int
69  * inet_pton4(src, dst)
70  *	like inet_aton() but without all the hexadecimal and shorthand.
71  * return:
72  *	1 if `src' is a valid dotted quad, else 0.
73  * notice:
74  *	does not touch `dst' unless it's returning 1.
75  * author:
76  *	Paul Vixie, 1996.
77  */
78 static int
79 inet_pton4(const char *src, u_char *dst)
80 {
81 	static const char digits[] = "0123456789";
82 	int saw_digit, octets, ch;
83 	u_char tmp[NS_INADDRSZ], *tp;
84 
85 	saw_digit = 0;
86 	octets = 0;
87 	*(tp = tmp) = 0;
88 	while ((ch = *src++) != '\0') {
89 		const char *pch;
90 
91 		if ((pch = strchr(digits, ch)) != NULL) {
92 			u_int new = *tp * 10 + (pch - digits);
93 
94 			if (saw_digit && *tp == 0)
95 				return (0);
96 			if (new > 255)
97 				return (0);
98 			*tp = new;
99 			if (!saw_digit) {
100 				if (++octets > 4)
101 					return (0);
102 				saw_digit = 1;
103 			}
104 		} else if (ch == '.' && saw_digit) {
105 			if (octets == 4)
106 				return (0);
107 			*++tp = 0;
108 			saw_digit = 0;
109 		} else
110 			return (0);
111 	}
112 	if (octets < 4)
113 		return (0);
114 	memcpy(dst, tmp, NS_INADDRSZ);
115 	return (1);
116 }
117 
118 /* int
119  * inet_pton6(src, dst)
120  *	convert presentation level address to network order binary form.
121  * return:
122  *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
123  * notice:
124  *	(1) does not touch `dst' unless it's returning 1.
125  *	(2) :: in a full address is silently ignored.
126  * credit:
127  *	inspired by Mark Andrews.
128  * author:
129  *	Paul Vixie, 1996.
130  */
131 static int
132 inet_pton6(const char *src, u_char *dst)
133 {
134 	static const char xdigits_l[] = "0123456789abcdef",
135 			  xdigits_u[] = "0123456789ABCDEF";
136 	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
137 	const char *xdigits, *curtok;
138 	int ch, seen_xdigits;
139 	u_int val;
140 
141 	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
142 	endp = tp + NS_IN6ADDRSZ;
143 	colonp = NULL;
144 	/* Leading :: requires some special handling. */
145 	if (*src == ':')
146 		if (*++src != ':')
147 			return (0);
148 	curtok = src;
149 	seen_xdigits = 0;
150 	val = 0;
151 	while ((ch = *src++) != '\0') {
152 		const char *pch;
153 
154 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
155 			pch = strchr((xdigits = xdigits_u), ch);
156 		if (pch != NULL) {
157 			val <<= 4;
158 			val |= (pch - xdigits);
159 			if (++seen_xdigits > 4)
160 				return (0);
161 			continue;
162 		}
163 		if (ch == ':') {
164 			curtok = src;
165 			if (!seen_xdigits) {
166 				if (colonp)
167 					return (0);
168 				colonp = tp;
169 				continue;
170 			} else if (*src == '\0') {
171 				return (0);
172 			}
173 			if (tp + NS_INT16SZ > endp)
174 				return (0);
175 			*tp++ = (u_char) (val >> 8) & 0xff;
176 			*tp++ = (u_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++ = (u_char) (val >> 8) & 0xff;
193 		*tp++ = (u_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 = 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 	memcpy(dst, tmp, NS_IN6ADDRSZ);
214 	return (1);
215 }
216 
217 /*
218  * Weak aliases for applications that use certain private entry points,
219  * and fail to include <arpa/inet.h>.
220  */
221 #undef inet_pton
222 __weak_reference(__inet_pton, inet_pton);
223 
224 /*! \file */
225