xref: /freebsd/sys/libkern/inet_pton.c (revision 640235e2c2ba32947f7c59d168437ffa1280f1e6)
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 <sys/param.h>
25 #include <sys/socket.h>
26 #include <sys/systm.h>
27 
28 #include <netinet/in.h>
29 
30 #if __FreeBSD_version < 700000
31 #define strchr index
32 #endif
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 *src, void *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 		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 #define NS_INADDRSZ	4
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 #define NS_IN6ADDRSZ	16
137 #define NS_INT16SZ	2
138 	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
139 	const char *xdigits, *curtok;
140 	int ch, seen_xdigits;
141 	u_int val;
142 
143 	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
144 	endp = tp + NS_IN6ADDRSZ;
145 	colonp = NULL;
146 	/* Leading :: requires some special handling. */
147 	if (*src == ':')
148 		if (*++src != ':')
149 			return (0);
150 	curtok = src;
151 	seen_xdigits = 0;
152 	val = 0;
153 	while ((ch = *src++) != '\0') {
154 		const char *pch;
155 
156 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
157 			pch = strchr((xdigits = xdigits_u), ch);
158 		if (pch != NULL) {
159 			val <<= 4;
160 			val |= (pch - xdigits);
161 			if (++seen_xdigits > 4)
162 				return (0);
163 			continue;
164 		}
165 		if (ch == ':') {
166 			curtok = src;
167 			if (!seen_xdigits) {
168 				if (colonp)
169 					return (0);
170 				colonp = tp;
171 				continue;
172 			} else if (*src == '\0') {
173 				return (0);
174 			}
175 			if (tp + NS_INT16SZ > endp)
176 				return (0);
177 			*tp++ = (u_char) (val >> 8) & 0xff;
178 			*tp++ = (u_char) val & 0xff;
179 			seen_xdigits = 0;
180 			val = 0;
181 			continue;
182 		}
183 		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
184 		    inet_pton4(curtok, tp) > 0) {
185 			tp += NS_INADDRSZ;
186 			seen_xdigits = 0;
187 			break;	/*%< '\\0' was seen by inet_pton4(). */
188 		}
189 		return (0);
190 	}
191 	if (seen_xdigits) {
192 		if (tp + NS_INT16SZ > endp)
193 			return (0);
194 		*tp++ = (u_char) (val >> 8) & 0xff;
195 		*tp++ = (u_char) val & 0xff;
196 	}
197 	if (colonp != NULL) {
198 		/*
199 		 * Since some memmove()'s erroneously fail to handle
200 		 * overlapping regions, we'll do the shift by hand.
201 		 */
202 		const int n = tp - colonp;
203 		int i;
204 
205 		if (tp == endp)
206 			return (0);
207 		for (i = 1; i <= n; i++) {
208 			endp[- i] = colonp[n - i];
209 			colonp[n - i] = 0;
210 		}
211 		tp = endp;
212 	}
213 	if (tp != endp)
214 		return (0);
215 	memcpy(dst, tmp, NS_IN6ADDRSZ);
216 	return (1);
217 }
218 
219 /*! \file */
220