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 $";
22 #endif /* LIBC_SCCS and not lint */
23 #include <sys/cdefs.h>
24 __FBSDID("$FreeBSD: stable/12/lib/libc/inet/inet_pton.c 326695 2017-12-08 15:57:29Z pfg $");
25 
26 #include "port_before.h"
27 #include <sys/param.h>
28 #include <sys/socket.h>
29 #include <netinet/in.h>
30 #include <arpa/inet.h>
31 #include <arpa/nameser.h>
32 #include <string.h>
33 #include <errno.h>
34 #include "port_after.h"
35 
36 /*%
37  * WARNING: Don't even consider trying to compile this on a system where
38  * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.
39  */
40 
41 static int	inet_pton4(const char *src, u_char *dst);
42 static int	inet_pton6(const char *src, u_char *dst);
43 
44 /* int
45  * inet_pton(af, src, dst)
46  *	convert from presentation format (which usually means ASCII printable)
47  *	to network format (which is usually some kind of binary format).
48  * return:
49  *	1 if the address was valid for the specified address family
50  *	0 if the address wasn't valid (`dst' is untouched in this case)
51  *	-1 if some other error occurred (`dst' is untouched in this case, too)
52  * author:
53  *	Paul Vixie, 1996.
54  */
55 int
inet_pton(int af,const char * __restrict src,void * __restrict dst)56 inet_pton(int af, const char * __restrict src, void * __restrict dst)
57 {
58 	switch (af) {
59 	case AF_INET:
60 		return (inet_pton4(src, dst));
61 	case AF_INET6:
62 		return (inet_pton6(src, dst));
63 	default:
64 		errno = EAFNOSUPPORT;
65 		return (-1);
66 	}
67 	/* NOTREACHED */
68 }
69 
70 /* int
71  * inet_pton4(src, dst)
72  *	like inet_aton() but without all the hexadecimal and shorthand.
73  * return:
74  *	1 if `src' is a valid dotted quad, else 0.
75  * notice:
76  *	does not touch `dst' unless it's returning 1.
77  * author:
78  *	Paul Vixie, 1996.
79  */
80 static int
inet_pton4(const char * src,u_char * dst)81 inet_pton4(const char *src, u_char *dst)
82 {
83 	static const char digits[] = "0123456789";
84 	int saw_digit, octets, ch;
85 	u_char tmp[NS_INADDRSZ], *tp;
86 
87 	saw_digit = 0;
88 	octets = 0;
89 	*(tp = tmp) = 0;
90 	while ((ch = *src++) != '\0') {
91 		const char *pch;
92 
93 		if ((pch = strchr(digits, ch)) != NULL) {
94 			u_int new = *tp * 10 + (pch - digits);
95 
96 			if (saw_digit && *tp == 0)
97 				return (0);
98 			if (new > 255)
99 				return (0);
100 			*tp = new;
101 			if (!saw_digit) {
102 				if (++octets > 4)
103 					return (0);
104 				saw_digit = 1;
105 			}
106 		} else if (ch == '.' && saw_digit) {
107 			if (octets == 4)
108 				return (0);
109 			*++tp = 0;
110 			saw_digit = 0;
111 		} else
112 			return (0);
113 	}
114 	if (octets < 4)
115 		return (0);
116 	memcpy(dst, tmp, NS_INADDRSZ);
117 	return (1);
118 }
119 
120 /* int
121  * inet_pton6(src, dst)
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  * notice:
126  *	(1) does not touch `dst' unless it's returning 1.
127  *	(2) :: in a full address is silently ignored.
128  * credit:
129  *	inspired by Mark Andrews.
130  * author:
131  *	Paul Vixie, 1996.
132  */
133 static int
inet_pton6(const char * src,u_char * dst)134 inet_pton6(const char *src, u_char *dst)
135 {
136 	static const char xdigits_l[] = "0123456789abcdef",
137 			  xdigits_u[] = "0123456789ABCDEF";
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 /*
220  * Weak aliases for applications that use certain private entry points,
221  * and fail to include <arpa/inet.h>.
222  */
223 #undef inet_pton
224 __weak_reference(__inet_pton, inet_pton);
225 
226 /*! \file */
227