xref: /freebsd/sys/libkern/inet_pton.c (revision eda14cbc264d6969b02f2b1994cef11148e914f1)
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 /*%
31  * WARNING: Don't even consider trying to compile this on a system where
32  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
33  */
34 
35 static int	inet_pton4(const char *src, u_char *dst);
36 static int	inet_pton6(const char *src, u_char *dst);
37 
38 /* int
39  * inet_pton(af, src, dst)
40  *	convert from presentation format (which usually means ASCII printable)
41  *	to network format (which is usually some kind of binary format).
42  * return:
43  *	1 if the address was valid for the specified address family
44  *	0 if the address wasn't valid (`dst' is untouched in this case)
45  *	-1 if some other error occurred (`dst' is untouched in this case, too)
46  * author:
47  *	Paul Vixie, 1996.
48  */
49 int
50 inet_pton(int af, const char *src, void *dst)
51 {
52 	switch (af) {
53 	case AF_INET:
54 		return (inet_pton4(src, dst));
55 	case AF_INET6:
56 		return (inet_pton6(src, dst));
57 	default:
58 		return (-1);
59 	}
60 	/* NOTREACHED */
61 }
62 
63 /* int
64  * inet_pton4(src, dst)
65  *	like inet_aton() but without all the hexadecimal and shorthand.
66  * return:
67  *	1 if `src' is a valid dotted quad, else 0.
68  * notice:
69  *	does not touch `dst' unless it's returning 1.
70  * author:
71  *	Paul Vixie, 1996.
72  */
73 static int
74 inet_pton4(const char *src, u_char *dst)
75 {
76 	static const char digits[] = "0123456789";
77 	int saw_digit, octets, ch;
78 #define NS_INADDRSZ	4
79 	u_char tmp[NS_INADDRSZ], *tp;
80 
81 	saw_digit = 0;
82 	octets = 0;
83 	*(tp = tmp) = 0;
84 	while ((ch = *src++) != '\0') {
85 		const char *pch;
86 
87 		if ((pch = strchr(digits, ch)) != NULL) {
88 			u_int new = *tp * 10 + (pch - digits);
89 
90 			if (saw_digit && *tp == 0)
91 				return (0);
92 			if (new > 255)
93 				return (0);
94 			*tp = new;
95 			if (!saw_digit) {
96 				if (++octets > 4)
97 					return (0);
98 				saw_digit = 1;
99 			}
100 		} else if (ch == '.' && saw_digit) {
101 			if (octets == 4)
102 				return (0);
103 			*++tp = 0;
104 			saw_digit = 0;
105 		} else
106 			return (0);
107 	}
108 	if (octets < 4)
109 		return (0);
110 	memcpy(dst, tmp, NS_INADDRSZ);
111 	return (1);
112 }
113 
114 /* int
115  * inet_pton6(src, dst)
116  *	convert presentation level address to network order binary form.
117  * return:
118  *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
119  * notice:
120  *	(1) does not touch `dst' unless it's returning 1.
121  *	(2) :: in a full address is silently ignored.
122  * credit:
123  *	inspired by Mark Andrews.
124  * author:
125  *	Paul Vixie, 1996.
126  */
127 static int
128 inet_pton6(const char *src, u_char *dst)
129 {
130 	static const char xdigits_l[] = "0123456789abcdef",
131 			  xdigits_u[] = "0123456789ABCDEF";
132 #define NS_IN6ADDRSZ	16
133 #define NS_INT16SZ	2
134 	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
135 	const char *xdigits, *curtok;
136 	int ch, seen_xdigits;
137 	u_int val;
138 
139 	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
140 	endp = tp + NS_IN6ADDRSZ;
141 	colonp = NULL;
142 	/* Leading :: requires some special handling. */
143 	if (*src == ':')
144 		if (*++src != ':')
145 			return (0);
146 	curtok = src;
147 	seen_xdigits = 0;
148 	val = 0;
149 	while ((ch = *src++) != '\0') {
150 		const char *pch;
151 
152 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
153 			pch = strchr((xdigits = xdigits_u), ch);
154 		if (pch != NULL) {
155 			val <<= 4;
156 			val |= (pch - xdigits);
157 			if (++seen_xdigits > 4)
158 				return (0);
159 			continue;
160 		}
161 		if (ch == ':') {
162 			curtok = src;
163 			if (!seen_xdigits) {
164 				if (colonp)
165 					return (0);
166 				colonp = tp;
167 				continue;
168 			} else if (*src == '\0') {
169 				return (0);
170 			}
171 			if (tp + NS_INT16SZ > endp)
172 				return (0);
173 			*tp++ = (u_char) (val >> 8) & 0xff;
174 			*tp++ = (u_char) val & 0xff;
175 			seen_xdigits = 0;
176 			val = 0;
177 			continue;
178 		}
179 		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
180 		    inet_pton4(curtok, tp) > 0) {
181 			tp += NS_INADDRSZ;
182 			seen_xdigits = 0;
183 			break;	/*%< '\\0' was seen by inet_pton4(). */
184 		}
185 		return (0);
186 	}
187 	if (seen_xdigits) {
188 		if (tp + NS_INT16SZ > endp)
189 			return (0);
190 		*tp++ = (u_char) (val >> 8) & 0xff;
191 		*tp++ = (u_char) val & 0xff;
192 	}
193 	if (colonp != NULL) {
194 		/*
195 		 * Since some memmove()'s erroneously fail to handle
196 		 * overlapping regions, we'll do the shift by hand.
197 		 */
198 		const int n = tp - colonp;
199 		int i;
200 
201 		if (tp == endp)
202 			return (0);
203 		for (i = 1; i <= n; i++) {
204 			endp[- i] = colonp[n - i];
205 			colonp[n - i] = 0;
206 		}
207 		tp = endp;
208 	}
209 	if (tp != endp)
210 		return (0);
211 	memcpy(dst, tmp, NS_IN6ADDRSZ);
212 	return (1);
213 }
214 
215 /*! \file */
216