xref: /netbsd-src/external/bsd/libbind/dist/resolv/res_comp.c (revision 5bbd2a12505d72a8177929a37b5cee489d0a1cfd)
1 /*	$NetBSD: res_comp.c,v 1.1.1.2 2012/09/09 16:08:08 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1985, 1993
5  *    The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  * 	This product includes software developed by the University of
18  * 	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 /*
37  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
38  *
39  * Permission to use, copy, modify, and distribute this software for any
40  * purpose with or without fee is hereby granted, provided that the above
41  * copyright notice and this permission notice appear in all copies, and that
42  * the name of Digital Equipment Corporation not be used in advertising or
43  * publicity pertaining to distribution of the document or software without
44  * specific, written prior permission.
45  *
46  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
47  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
48  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
49  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
50  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
51  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
52  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
53  * SOFTWARE.
54  */
55 
56 /*
57  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
58  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
59  *
60  * Permission to use, copy, modify, and distribute this software for any
61  * purpose with or without fee is hereby granted, provided that the above
62  * copyright notice and this permission notice appear in all copies.
63  *
64  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
65  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
66  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
67  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
68  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
69  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
70  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
71  */
72 
73 #if defined(LIBC_SCCS) && !defined(lint)
74 static const char sccsid[] = "@(#)res_comp.c	8.1 (Berkeley) 6/4/93";
75 static const char rcsid[] = "Id: res_comp.c,v 1.5 2005/07/28 06:51:50 marka Exp ";
76 #endif /* LIBC_SCCS and not lint */
77 
78 #include "port_before.h"
79 #include <sys/types.h>
80 #include <sys/param.h>
81 #include <netinet/in.h>
82 #include <arpa/nameser.h>
83 #include <ctype.h>
84 #include <resolv.h>
85 #include <stdio.h>
86 #include <string.h>
87 #include <unistd.h>
88 #include "port_after.h"
89 
90 /*%
91  * Expand compressed domain name 'src' to full domain name.
92  *
93  * \li 'msg' is a pointer to the begining of the message,
94  * \li 'eom' points to the first location after the message,
95  * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result.
96  * \li Return size of compressed name or -1 if there was an error.
97  */
98 int
dn_expand(const u_char * msg,const u_char * eom,const u_char * src,char * dst,int dstsiz)99 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
100 	  char *dst, int dstsiz)
101 {
102 	int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
103 
104 	if (n > 0 && dst[0] == '.')
105 		dst[0] = '\0';
106 	return (n);
107 }
108 
109 /*%
110  * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
111  *
112  * \li Return the size of the compressed name or -1.
113  * \li 'length' is the size of the array pointed to by 'comp_dn'.
114  */
115 int
dn_comp(const char * src,u_char * dst,int dstsiz,u_char ** dnptrs,u_char ** lastdnptr)116 dn_comp(const char *src, u_char *dst, int dstsiz,
117 	u_char **dnptrs, u_char **lastdnptr)
118 {
119 	return (ns_name_compress(src, dst, (size_t)dstsiz,
120 				 (const u_char **)dnptrs,
121 				 (const u_char **)lastdnptr));
122 }
123 
124 /*%
125  * Skip over a compressed domain name. Return the size or -1.
126  */
127 int
dn_skipname(const u_char * ptr,const u_char * eom)128 dn_skipname(const u_char *ptr, const u_char *eom) {
129 	const u_char *saveptr = ptr;
130 
131 	if (ns_name_skip(&ptr, eom) == -1)
132 		return (-1);
133 	return (ptr - saveptr);
134 }
135 
136 /*%
137  * Verify that a domain name uses an acceptable character set.
138  *
139  * Note the conspicuous absence of ctype macros in these definitions.  On
140  * non-ASCII hosts, we can't depend on string literals or ctype macros to
141  * tell us anything about network-format data.  The rest of the BIND system
142  * is not careful about this, but for some reason, we're doing it right here.
143  */
144 #define PERIOD 0x2e
145 #define	hyphenchar(c) ((c) == 0x2d)
146 #define bslashchar(c) ((c) == 0x5c)
147 #define periodchar(c) ((c) == PERIOD)
148 #define asterchar(c) ((c) == 0x2a)
149 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
150 		   || ((c) >= 0x61 && (c) <= 0x7a))
151 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
152 
153 #define borderchar(c) (alphachar(c) || digitchar(c))
154 #define middlechar(c) (borderchar(c) || hyphenchar(c))
155 #define	domainchar(c) ((c) > 0x20 && (c) < 0x7f)
156 
157 int
res_hnok(const char * dn)158 res_hnok(const char *dn) {
159 	int pch = PERIOD, ch = *dn++;
160 
161 	while (ch != '\0') {
162 		int nch = *dn++;
163 
164 		if (periodchar(ch)) {
165 			(void)NULL;
166 		} else if (periodchar(pch)) {
167 			if (!borderchar(ch))
168 				return (0);
169 		} else if (periodchar(nch) || nch == '\0') {
170 			if (!borderchar(ch))
171 				return (0);
172 		} else {
173 			if (!middlechar(ch))
174 				return (0);
175 		}
176 		pch = ch, ch = nch;
177 	}
178 	return (1);
179 }
180 
181 /*%
182  * hostname-like (A, MX, WKS) owners can have "*" as their first label
183  * but must otherwise be as a host name.
184  */
185 int
res_ownok(const char * dn)186 res_ownok(const char *dn) {
187 	if (asterchar(dn[0])) {
188 		if (periodchar(dn[1]))
189 			return (res_hnok(dn+2));
190 		if (dn[1] == '\0')
191 			return (1);
192 	}
193 	return (res_hnok(dn));
194 }
195 
196 /*%
197  * SOA RNAMEs and RP RNAMEs can have any printable character in their first
198  * label, but the rest of the name has to look like a host name.
199  */
200 int
res_mailok(const char * dn)201 res_mailok(const char *dn) {
202 	int ch, escaped = 0;
203 
204 	/* "." is a valid missing representation */
205 	if (*dn == '\0')
206 		return (1);
207 
208 	/* otherwise <label>.<hostname> */
209 	while ((ch = *dn++) != '\0') {
210 		if (!domainchar(ch))
211 			return (0);
212 		if (!escaped && periodchar(ch))
213 			break;
214 		if (escaped)
215 			escaped = 0;
216 		else if (bslashchar(ch))
217 			escaped = 1;
218 	}
219 	if (periodchar(ch))
220 		return (res_hnok(dn));
221 	return (0);
222 }
223 
224 /*%
225  * This function is quite liberal, since RFC1034's character sets are only
226  * recommendations.
227  */
228 int
res_dnok(const char * dn)229 res_dnok(const char *dn) {
230 	int ch;
231 
232 	while ((ch = *dn++) != '\0')
233 		if (!domainchar(ch))
234 			return (0);
235 	return (1);
236 }
237 
238 #ifdef BIND_4_COMPAT
239 /*%
240  * This module must export the following externally-visible symbols:
241  *	___putlong
242  *	___putshort
243  *	__getlong
244  *	__getshort
245  * Note that one _ comes from C and the others come from us.
246  */
247 
248 #ifdef SOLARIS2
249 #ifdef  __putlong
250 #undef  __putlong
251 #endif
252 #ifdef  __putshort
253 #undef  __putshort
254 #endif
255 #pragma weak    putlong         =       __putlong
256 #pragma weak    putshort        =       __putshort
257 #endif /* SOLARIS2 */
258 
__putlong(u_int32_t src,u_char * dst)259 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
__putshort(u_int16_t src,u_char * dst)260 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
261 #ifndef __ultrix__
_getlong(const u_char * src)262 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
_getshort(const u_char * src)263 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
264 #endif /*__ultrix__*/
265 #endif /*BIND_4_COMPAT*/
266 
267 /*! \file */
268