xref: /freebsd/contrib/ntp/libntp/lib/isc/inet_pton.c (revision ba3c1f5972d7b90feb6e6da47905ff2757e0fe57)
1 /*
2  * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (C) 1996-2003  Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and/or 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 WITH
10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15  * PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /*! \file */
19 
20 #if defined(LIBC_SCCS) && !defined(lint)
21 static char rcsid[] =
22 	"$Id: inet_pton.c,v 1.19 2007/06/19 23:47:17 tbox Exp $";
23 #endif /* LIBC_SCCS and not lint */
24 
25 #include <config.h>
26 
27 #include <errno.h>
28 #include <string.h>
29 
30 #include <isc/net.h>
31 
32 /*% INT16 Size */
33 #define NS_INT16SZ	 2
34 /*% IPv4 Address Size */
35 #define NS_INADDRSZ	 4
36 /*% IPv6 Address Size */
37 #define NS_IN6ADDRSZ	16
38 
39 /*
40  * WARNING: Don't even consider trying to compile this on a system where
41  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
42  */
43 
44 static int inet_pton4(const char *src, unsigned char *dst);
45 static int inet_pton6(const char *src, unsigned char *dst);
46 int isc_net_pton(int af, const char *src, void *dst);
47 
48 /*%
49  *	convert from presentation format (which usually means ASCII printable)
50  *	to network format (which is usually some kind of binary format).
51  * \return
52  *	1 if the address was valid for the specified address family
53  *	0 if the address wasn't valid (`dst' is untouched in this case)
54  *	-1 if some other error occurred (`dst' is untouched in this case, too)
55  * \author
56  *	Paul Vixie, 1996.
57  */
58 int
59 isc_net_pton(int af, const char *src, void *dst) {
60 	switch (af) {
61 	case AF_INET:
62 		return (inet_pton4(src, dst));
63 	case AF_INET6:
64 		return (inet_pton6(src, dst));
65 	default:
66 		errno = EAFNOSUPPORT;
67 		return (-1);
68 	}
69 	/* NOTREACHED */
70 }
71 
72 /*!\fn static int inet_pton4(const char *src, unsigned char *dst)
73  * \brief
74  *	like inet_aton() but without all the hexadecimal and shorthand.
75  * \return
76  *	1 if `src' is a valid dotted quad, else 0.
77  * \note
78  *	does not touch `dst' unless it's returning 1.
79  * \author
80  *	Paul Vixie, 1996.
81  */
82 static int
83 inet_pton4(const char *src, unsigned char *dst) {
84 	static const char digits[] = "0123456789";
85 	int saw_digit, octets, ch;
86 	unsigned char tmp[NS_INADDRSZ], *tp;
87 
88 	saw_digit = 0;
89 	octets = 0;
90 	*(tp = tmp) = 0;
91 	while ((ch = *src++) != '\0') {
92 		const char *pch;
93 
94 		if ((pch = strchr(digits, ch)) != NULL) {
95 			size_t newv = *tp * 10 + (pch - digits);
96 
97 			if (saw_digit && *tp == 0)
98 				return (0);
99 			if (newv > 255)
100 				return (0);
101 			*tp = (unsigned char)newv;
102 			if (!saw_digit) {
103 				if (++octets > 4)
104 					return (0);
105 				saw_digit = 1;
106 			}
107 		} else if (ch == '.' && saw_digit) {
108 			if (octets == 4)
109 				return (0);
110 			*++tp = 0;
111 			saw_digit = 0;
112 		} else
113 			return (0);
114 	}
115 	if (octets < 4)
116 		return (0);
117 	memcpy(dst, tmp, NS_INADDRSZ);
118 	return (1);
119 }
120 
121 /*%
122  *	convert presentation level address to network order binary form.
123  * \return
124  *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
125  * \note
126  *	(1) does not touch `dst' unless it's returning 1.
127  * \note
128  *	(2) :: in a full address is silently ignored.
129  * \author
130  *	inspired by Mark Andrews.
131  * \author
132  *	Paul Vixie, 1996.
133  */
134 static int
135 inet_pton6(const char *src, unsigned char *dst) {
136 	static const char xdigits_l[] = "0123456789abcdef",
137 			  xdigits_u[] = "0123456789ABCDEF";
138 	unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
139 	const char *xdigits, *curtok;
140 	int ch, seen_xdigits;
141 	unsigned 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 			}
173 			if (NS_INT16SZ > endp - tp)
174 				return (0);
175 			*tp++ = (unsigned char) (val >> 8) & 0xff;
176 			*tp++ = (unsigned char) val & 0xff;
177 			seen_xdigits = 0;
178 			val = 0;
179 			continue;
180 		}
181 		if (ch == '.' && (NS_INADDRSZ <= endp - tp) &&
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 (NS_INT16SZ > endp - tp)
191 			return (0);
192 		*tp++ = (unsigned char) (val >> 8) & 0xff;
193 		*tp++ = (unsigned 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 size_t n = tp - colonp;
201 		int i;
202 
203 		if (tp == endp)
204 			return (0);
205 		for (i = 1; (size_t)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