1 /*-
2 * SPDX-License-Identifier: (BSD-3-Clause AND ISC)
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
69 #include "port_before.h"
70 #include <sys/param.h>
71 #include <netinet/in.h>
72 #include <arpa/nameser.h>
73 #include <ctype.h>
74 #include <resolv.h>
75 #include <stdio.h>
76 #include <string.h>
77 #include <unistd.h>
78 #include "port_after.h"
79
80 /*%
81 * Expand compressed domain name 'src' to full domain name.
82 *
83 * \li 'msg' is a pointer to the beginning of the message,
84 * \li 'eom' points to the first location after the message,
85 * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result.
86 * \li Return size of compressed name or -1 if there was an error.
87 */
88 int
dn_expand(const u_char * msg,const u_char * eom,const u_char * src,char * dst,int dstsiz)89 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
90 char *dst, int dstsiz)
91 {
92 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
93
94 if (n > 0 && dst[0] == '.')
95 dst[0] = '\0';
96 return (n);
97 }
98
99 /*%
100 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
101 *
102 * \li Return the size of the compressed name or -1.
103 * \li 'length' is the size of the array pointed to by 'comp_dn'.
104 */
105 int
dn_comp(const char * src,u_char * dst,int dstsiz,u_char ** dnptrs,u_char ** lastdnptr)106 dn_comp(const char *src, u_char *dst, int dstsiz,
107 u_char **dnptrs, u_char **lastdnptr)
108 {
109 return (ns_name_compress(src, dst, (size_t)dstsiz,
110 (const u_char **)dnptrs,
111 (const u_char **)lastdnptr));
112 }
113
114 /*%
115 * Skip over a compressed domain name. Return the size or -1.
116 */
117 int
dn_skipname(const u_char * ptr,const u_char * eom)118 dn_skipname(const u_char *ptr, const u_char *eom) {
119 const u_char *saveptr = ptr;
120
121 if (ns_name_skip(&ptr, eom) == -1)
122 return (-1);
123 return (ptr - saveptr);
124 }
125
126 /*%
127 * Verify that a domain name uses an acceptable character set.
128 *
129 * Note the conspicuous absence of ctype macros in these definitions. On
130 * non-ASCII hosts, we can't depend on string literals or ctype macros to
131 * tell us anything about network-format data. The rest of the BIND system
132 * is not careful about this, but for some reason, we're doing it right here.
133 */
134 #define PERIOD 0x2e
135 #define hyphenchar(c) ((c) == 0x2d)
136 #define bslashchar(c) ((c) == 0x5c)
137 #define underscorechar(c) ((c) == 0x5f)
138 #define periodchar(c) ((c) == PERIOD)
139 #define asterchar(c) ((c) == 0x2a)
140 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
141 || ((c) >= 0x61 && (c) <= 0x7a))
142 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
143
144 #ifdef RES_ENFORCE_RFC1034
145 #define borderchar(c) (alphachar(c) || digitchar(c))
146 #else
147 #define borderchar(c) (alphachar(c) || digitchar(c) || underscorechar(c))
148 #endif
149 #define middlechar(c) (borderchar(c) || hyphenchar(c))
150 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
151
152 int
res_hnok(const char * dn)153 res_hnok(const char *dn) {
154 int pch = PERIOD, ch = *dn++;
155
156 while (ch != '\0') {
157 int nch = *dn++;
158
159 if (periodchar(ch)) {
160 (void)NULL;
161 } else if (periodchar(pch)) {
162 if (!borderchar(ch))
163 return (0);
164 } else if (periodchar(nch) || nch == '\0') {
165 if (!borderchar(ch))
166 return (0);
167 } else {
168 if (!middlechar(ch))
169 return (0);
170 }
171 pch = ch, ch = nch;
172 }
173 return (1);
174 }
175
176 /*%
177 * hostname-like (A, MX, WKS) owners can have "*" as their first label
178 * but must otherwise be as a host name.
179 */
180 int
res_ownok(const char * dn)181 res_ownok(const char *dn) {
182 if (asterchar(dn[0])) {
183 if (periodchar(dn[1]))
184 return (res_hnok(dn+2));
185 if (dn[1] == '\0')
186 return (1);
187 }
188 return (res_hnok(dn));
189 }
190
191 /*%
192 * SOA RNAMEs and RP RNAMEs can have any printable character in their first
193 * label, but the rest of the name has to look like a host name.
194 */
195 int
res_mailok(const char * dn)196 res_mailok(const char *dn) {
197 int ch, escaped = 0;
198
199 /* "." is a valid missing representation */
200 if (*dn == '\0')
201 return (1);
202
203 /* otherwise <label>.<hostname> */
204 while ((ch = *dn++) != '\0') {
205 if (!domainchar(ch))
206 return (0);
207 if (!escaped && periodchar(ch))
208 break;
209 if (escaped)
210 escaped = 0;
211 else if (bslashchar(ch))
212 escaped = 1;
213 }
214 if (periodchar(ch))
215 return (res_hnok(dn));
216 return (0);
217 }
218
219 /*%
220 * This function is quite liberal, since RFC1034's character sets are only
221 * recommendations.
222 */
223 int
res_dnok(const char * dn)224 res_dnok(const char *dn) {
225 int ch;
226
227 while ((ch = *dn++) != '\0')
228 if (!domainchar(ch))
229 return (0);
230 return (1);
231 }
232
233 #ifdef BIND_4_COMPAT
234 /*%
235 * This module must export the following externally-visible symbols:
236 * ___putlong
237 * ___putshort
238 * __getlong
239 * __getshort
240 * Note that one _ comes from C and the others come from us.
241 */
242
243 #ifdef SOLARIS2
244 #ifdef __putlong
245 #undef __putlong
246 #endif
247 #ifdef __putshort
248 #undef __putshort
249 #endif
250 #pragma weak putlong = __putlong
251 #pragma weak putshort = __putshort
252 #endif /* SOLARIS2 */
253
__putlong(u_int32_t src,u_char * dst)254 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
__putshort(u_int16_t src,u_char * dst)255 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
256 #ifndef __ultrix__
_getlong(const u_char * src)257 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
_getshort(const u_char * src)258 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
259 #endif /*__ultrix__*/
260 #endif /*BIND_4_COMPAT*/
261
262 /*
263 * Weak aliases for applications that use certain private entry points,
264 * and fail to include <resolv.h>.
265 */
266 #undef dn_comp
267 __weak_reference(__dn_comp, dn_comp);
268 #undef dn_expand
269 __weak_reference(__dn_expand, dn_expand);
270
271 /*! \file */
272