1 /* $NetBSD: res_comp.c,v 1.13 2015/02/24 17:56:20 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. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 /*
33 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
34 *
35 * Permission to use, copy, modify, and distribute this software for any
36 * purpose with or without fee is hereby granted, provided that the above
37 * copyright notice and this permission notice appear in all copies, and that
38 * the name of Digital Equipment Corporation not be used in advertising or
39 * publicity pertaining to distribution of the document or software without
40 * specific, written prior permission.
41 *
42 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
43 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
44 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
45 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
46 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
47 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
48 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
49 * SOFTWARE.
50 */
51
52 /*
53 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
54 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
55 *
56 * Permission to use, copy, modify, and distribute this software for any
57 * purpose with or without fee is hereby granted, provided that the above
58 * copyright notice and this permission notice appear in all copies.
59 *
60 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
61 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
62 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
63 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
64 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
65 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
66 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
67 */
68 #include <sys/cdefs.h>
69 #if defined(LIBC_SCCS) && !defined(lint)
70 #ifdef notdef
71 static const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93";
72 static const char rcsid[] = "Id: res_comp.c,v 1.5 2005/07/28 06:51:50 marka Exp";
73 #else
74 __RCSID("$NetBSD: res_comp.c,v 1.13 2015/02/24 17:56:20 christos Exp $");
75 #endif
76 #endif /* LIBC_SCCS and not lint */
77
78 #include "port_before.h"
79
80 #include "namespace.h"
81 #include <sys/types.h>
82 #include <sys/param.h>
83 #include <netinet/in.h>
84 #include <arpa/nameser.h>
85 #include <assert.h>
86 #include <ctype.h>
87 #include <resolv.h>
88 #include <stdio.h>
89 #include <string.h>
90 #include <unistd.h>
91 #include "port_after.h"
92
93 #ifdef __weak_alias
__weak_alias(dn_expand,_dn_expand)94 __weak_alias(dn_expand,_dn_expand)
95 __weak_alias(dn_comp,__dn_comp)
96 #if defined(__minix)
97 __weak_alias(dn_skipname,__dn_skipname)
98 __weak_alias(res_hnok,__res_hnok)
99 __weak_alias(res_ownok,__res_ownok)
100 __weak_alias(res_mailok,__res_mailok)
101 __weak_alias(res_dnok,__res_dnok)
102 #endif /* defined(__minix) */
103 #endif
104
105 /*%
106 * Expand compressed domain name 'src' to full domain name.
107 *
108 * \li 'msg' is a pointer to the begining of the message,
109 * \li 'eom' points to the first location after the message,
110 * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result.
111 * \li Return size of compressed name or -1 if there was an error.
112 */
113 int
114 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
115 char *dst, int dstsiz)
116 {
117 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
118
119 if (n > 0 && dst[0] == '.')
120 dst[0] = '\0';
121 return (n);
122 }
123
124 /*%
125 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
126 *
127 * \li Return the size of the compressed name or -1.
128 * \li 'length' is the size of the array pointed to by 'comp_dn'.
129 */
130 int
dn_comp(const char * src,u_char * dst,int dstsiz,u_char ** dnptrs,u_char ** lastdnptr)131 dn_comp(const char *src, u_char *dst, int dstsiz,
132 u_char **dnptrs, u_char **lastdnptr)
133 {
134 return (ns_name_compress(src, dst, (size_t)dstsiz,
135 (void *)dnptrs,
136 (void *)lastdnptr));
137 }
138
139 /*%
140 * Skip over a compressed domain name. Return the size or -1.
141 */
142 int
dn_skipname(const u_char * ptr,const u_char * eom)143 dn_skipname(const u_char *ptr, const u_char *eom) {
144 const u_char *saveptr = ptr;
145
146 if (ns_name_skip(&ptr, eom) == -1)
147 return (-1);
148 _DIAGASSERT(__type_fit(int, ptr - saveptr));
149 return (int)(ptr - saveptr);
150 }
151
152 /*%
153 * Verify that a domain name uses an acceptable character set.
154 *
155 * Note the conspicuous absence of ctype macros in these definitions. On
156 * non-ASCII hosts, we can't depend on string literals or ctype macros to
157 * tell us anything about network-format data. The rest of the BIND system
158 * is not careful about this, but for some reason, we're doing it right here.
159 */
160 #define PERIOD 0x2e
161 #define hyphenchar(c) ((c) == 0x2d)
162 #define bslashchar(c) ((c) == 0x5c)
163 #define periodchar(c) ((c) == PERIOD)
164 #define asterchar(c) ((c) == 0x2a)
165 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
166 || ((c) >= 0x61 && (c) <= 0x7a))
167 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
168
169 #define borderchar(c) (alphachar(c) || digitchar(c))
170 #define middlechar(c) (borderchar(c) || hyphenchar(c))
171 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
172
173 int
res_hnok(const char * dn)174 res_hnok(const char *dn) {
175 int pch = PERIOD, ch = *dn++;
176
177 while (ch != '\0') {
178 int nch = *dn++;
179
180 if (periodchar(ch)) {
181 ;
182 } else if (periodchar(pch)) {
183 if (!borderchar(ch))
184 return (0);
185 } else if (periodchar(nch) || nch == '\0') {
186 if (!borderchar(ch))
187 return (0);
188 } else {
189 if (!middlechar(ch))
190 return (0);
191 }
192 pch = ch, ch = nch;
193 }
194 return (1);
195 }
196
197 /*%
198 * hostname-like (A, MX, WKS) owners can have "*" as their first label
199 * but must otherwise be as a host name.
200 */
201 int
res_ownok(const char * dn)202 res_ownok(const char *dn) {
203 if (asterchar(dn[0])) {
204 if (periodchar(dn[1]))
205 return (res_hnok(dn+2));
206 if (dn[1] == '\0')
207 return (1);
208 }
209 return (res_hnok(dn));
210 }
211
212 /*%
213 * SOA RNAMEs and RP RNAMEs can have any printable character in their first
214 * label, but the rest of the name has to look like a host name.
215 */
216 int
res_mailok(const char * dn)217 res_mailok(const char *dn) {
218 int ch, escaped = 0;
219
220 /* "." is a valid missing representation */
221 if (*dn == '\0')
222 return (1);
223
224 /* otherwise <label>.<hostname> */
225 while ((ch = *dn++) != '\0') {
226 if (!domainchar(ch))
227 return (0);
228 if (!escaped && periodchar(ch))
229 break;
230 if (escaped)
231 escaped = 0;
232 else if (bslashchar(ch))
233 escaped = 1;
234 }
235 if (periodchar(ch))
236 return (res_hnok(dn));
237 return (0);
238 }
239
240 /*%
241 * This function is quite liberal, since RFC1034's character sets are only
242 * recommendations.
243 */
244 int
res_dnok(const char * dn)245 res_dnok(const char *dn) {
246 int ch;
247
248 while ((ch = *dn++) != '\0')
249 if (!domainchar(ch))
250 return (0);
251 return (1);
252 }
253
254 #ifdef BIND_4_COMPAT
255 /*%
256 * This module must export the following externally-visible symbols:
257 * ___putlong
258 * ___putshort
259 * __getlong
260 * __getshort
261 * Note that one _ comes from C and the others come from us.
262 */
263
264 #ifdef SOLARIS2
265 #ifdef __putlong
266 #undef __putlong
267 #endif
268 #ifdef __putshort
269 #undef __putshort
270 #endif
271 #pragma weak putlong = __putlong
272 #pragma weak putshort = __putshort
273 #endif /* SOLARIS2 */
274
__putlong(u_int32_t src,u_char * dst)275 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
__putshort(u_int16_t src,u_char * dst)276 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
277 #ifndef __ultrix__
_getlong(const u_char * src)278 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
_getshort(const u_char * src)279 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
280 #endif /*__ultrix__*/
281 #endif /*BIND_4_COMPAT*/
282
283 /*! \file */
284