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[glibc.git] / resolv / res_comp.c
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1 /*
2 * Copyright (c) 1985, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
31 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
33 * Permission to use, copy, modify, and distribute this software for any
34 * purpose with or without fee is hereby granted, provided that the above
35 * copyright notice and this permission notice appear in all copies, and that
36 * the name of Digital Equipment Corporation not be used in advertising or
37 * publicity pertaining to distribution of the document or software without
38 * specific, written prior permission.
40 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
41 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
42 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
43 * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
44 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
45 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
46 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
47 * SOFTWARE.
51 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
53 * Permission to use, copy, modify, and distribute this software for any
54 * purpose with or without fee is hereby granted, provided that the above
55 * copyright notice and this permission notice appear in all copies.
57 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
58 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
59 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
60 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
61 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
62 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
63 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
64 * SOFTWARE.
67 #if defined(LIBC_SCCS) && !defined(lint)
68 static const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93";
69 static const char rcsid[] = "$BINDId: res_comp.c,v 8.15 1999/10/13 16:39:39 vixie Exp $";
70 #endif /* LIBC_SCCS and not lint */
72 #include <sys/types.h>
73 #include <sys/param.h>
74 #include <netinet/in.h>
75 #include <arpa/nameser.h>
76 #include <ctype.h>
77 #include <resolv.h>
78 #include <stdio.h>
79 #include <string.h>
80 #include <unistd.h>
83 * Expand compressed domain name 'comp_dn' to full domain name.
84 * 'msg' is a pointer to the begining of the message,
85 * 'eomorig' points to the first location after the message,
86 * 'exp_dn' is a pointer to a buffer of size 'length' for the result.
87 * Return size of compressed name or -1 if there was an error.
89 int
90 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
91 char *dst, int dstsiz)
93 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
95 if (n > 0 && dst[0] == '.')
96 dst[0] = '\0';
97 return (n);
101 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
102 * Return the size of the compressed name or -1.
103 * 'length' is the size of the array pointed to by 'comp_dn'.
106 dn_comp(const char *src, u_char *dst, int dstsiz,
107 u_char **dnptrs, u_char **lastdnptr)
109 return (ns_name_compress(src, dst, (size_t)dstsiz,
110 (const u_char **)dnptrs,
111 (const u_char **)lastdnptr));
115 * Skip over a compressed domain name. Return the size or -1.
118 dn_skipname(const u_char *ptr, const u_char *eom) {
119 const u_char *saveptr = ptr;
121 if (ns_name_skip(&ptr, eom) == -1)
122 return (-1);
123 return (ptr - saveptr);
127 * Verify that a domain name uses an acceptable character set.
131 * Note the conspicuous absence of ctype macros in these definitions. On
132 * non-ASCII hosts, we can't depend on string literals or ctype macros to
133 * tell us anything about network-format data. The rest of the BIND system
134 * is not careful about this, but for some reason, we're doing it right here.
136 #define PERIOD 0x2e
137 #define hyphenchar(c) ((c) == 0x2d)
138 #define underscorechar(c) ((c) == 0x5f)
139 #define bslashchar(c) ((c) == 0x5c)
140 #define periodchar(c) ((c) == PERIOD)
141 #define asterchar(c) ((c) == 0x2a)
142 #define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
143 || ((c) >= 0x61 && (c) <= 0x7a))
144 #define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
146 #define borderchar(c) (alphachar(c) || digitchar(c))
147 #define middlechar(c) (borderchar(c) || hyphenchar(c) || underscorechar(c))
148 #define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
151 res_hnok(const char *dn) {
152 int ppch = '\0', pch = PERIOD, ch = *dn++;
154 while (ch != '\0') {
155 int nch = *dn++;
157 if (periodchar(ch)) {
158 (void)NULL;
159 } else if (periodchar(pch)) {
160 if (!borderchar(ch))
161 return (0);
162 } else if (periodchar(nch) || nch == '\0') {
163 if (!borderchar(ch))
164 return (0);
165 } else {
166 if (!middlechar(ch))
167 return (0);
169 ppch = pch, pch = ch, ch = nch;
171 return (1);
175 * hostname-like (A, MX, WKS) owners can have "*" as their first label
176 * but must otherwise be as a host name.
179 res_ownok(const char *dn) {
180 if (asterchar(dn[0])) {
181 if (periodchar(dn[1]))
182 return (res_hnok(dn+2));
183 if (dn[1] == '\0')
184 return (1);
186 return (res_hnok(dn));
190 * SOA RNAMEs and RP RNAMEs can have any printable character in their first
191 * label, but the rest of the name has to look like a host name.
194 res_mailok(const char *dn) {
195 int ch, escaped = 0;
197 /* "." is a valid missing representation */
198 if (*dn == '\0')
199 return (1);
201 /* otherwise <label>.<hostname> */
202 while ((ch = *dn++) != '\0') {
203 if (!domainchar(ch))
204 return (0);
205 if (!escaped && periodchar(ch))
206 break;
207 if (escaped)
208 escaped = 0;
209 else if (bslashchar(ch))
210 escaped = 1;
212 if (periodchar(ch))
213 return (res_hnok(dn));
214 return (0);
218 * This function is quite liberal, since RFC 1034's character sets are only
219 * recommendations.
222 res_dnok(const char *dn) {
223 int ch;
225 while ((ch = *dn++) != '\0')
226 if (!domainchar(ch))
227 return (0);
228 return (1);
231 #ifdef BIND_4_COMPAT
233 * This module must export the following externally-visible symbols:
234 * ___putlong
235 * ___putshort
236 * __getlong
237 * __getshort
238 * Note that one _ comes from C and the others come from us.
240 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
241 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
242 #ifndef __ultrix__
243 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
244 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
245 #endif /*__ultrix__*/
246 #endif /*BIND_4_COMPAT*/
249 #include <shlib-compat.h>
251 #if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
252 # undef dn_expand
253 weak_alias (__dn_expand, dn_expand);
254 #endif