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.
16 *
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.
28 */
29
30/*
31 * Portions Copyright (c) 1993 by Digital Equipment Corporation.
32 *
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.
39 *
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.
48 */
49
50/*
51 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
52 *
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.
56 *
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.
65 */
66
67#if defined(LIBC_SCCS) && !defined(lint)
68static const char sccsid[] = "@(#)res_comp.c 8.1 (Berkeley) 6/4/93";
69static 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 */
71
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>
81
82/*
83 * Expand compressed domain name 'comp_dn' to full domain name.
84 * 'msg' is a pointer to the beginning 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.
88 */
89int
90dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
91 char *dst, int dstsiz)
92{
93 int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
94
95 if (n > 0 && dst[0] == '.')
96 dst[0] = '\0';
97 return (n);
98}
99libresolv_hidden_def (dn_expand)
100
101/*
102 * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
103 * Return the size of the compressed name or -1.
104 * 'length' is the size of the array pointed to by 'comp_dn'.
105 */
106int
107dn_comp(const char *src, u_char *dst, int dstsiz,
108 u_char **dnptrs, u_char **lastdnptr)
109{
110 return (ns_name_compress(src, dst, (size_t)dstsiz,
111 (const u_char **)dnptrs,
112 (const u_char **)lastdnptr));
113}
114libresolv_hidden_def (dn_comp)
115
116/*
117 * Skip over a compressed domain name. Return the size or -1.
118 */
119int
120dn_skipname(const u_char *ptr, const u_char *eom) {
121 const u_char *saveptr = ptr;
122
123 if (ns_name_skip(&ptr, eom) == -1)
124 return (-1);
125 return (ptr - saveptr);
126}
127libresolv_hidden_def (dn_skipname)
128
129/*
130 * Verify that a domain name uses an acceptable character set.
131 */
132
133/*
134 * Note the conspicuous absence of ctype macros in these definitions. On
135 * non-ASCII hosts, we can't depend on string literals or ctype macros to
136 * tell us anything about network-format data. The rest of the BIND system
137 * is not careful about this, but for some reason, we're doing it right here.
138 */
139#define PERIOD 0x2e
140#define hyphenchar(c) ((c) == 0x2d)
141#define underscorechar(c) ((c) == 0x5f)
142#define bslashchar(c) ((c) == 0x5c)
143#define periodchar(c) ((c) == PERIOD)
144#define asterchar(c) ((c) == 0x2a)
145#define alphachar(c) (((c) >= 0x41 && (c) <= 0x5a) \
146 || ((c) >= 0x61 && (c) <= 0x7a))
147#define digitchar(c) ((c) >= 0x30 && (c) <= 0x39)
148
149#define borderchar(c) (alphachar(c) || digitchar(c))
150#define middlechar(c) (borderchar(c) || hyphenchar(c) || underscorechar(c))
151#define domainchar(c) ((c) > 0x20 && (c) < 0x7f)
152
153int
154res_hnok(const char *dn) {
155 int pch = PERIOD, ch = *dn++;
156
157 while (ch != '\0') {
158 int nch = *dn++;
159
160 if (periodchar(ch)) {
161 (void)NULL;
162 } else if (periodchar(pch)) {
163 if (!borderchar(ch))
164 return (0);
165 } else if (periodchar(nch) || nch == '\0') {
166 if (!borderchar(ch))
167 return (0);
168 } else {
169 if (!middlechar(ch))
170 return (0);
171 }
172 pch = ch, ch = nch;
173 }
174 return (1);
175}
176libresolv_hidden_def (res_hnok)
177
178/*
179 * hostname-like (A, MX, WKS) owners can have "*" as their first label
180 * but must otherwise be as a host name.
181 */
182int
183res_ownok(const char *dn) {
184 if (asterchar(dn[0])) {
185 if (periodchar(dn[1]))
186 return (res_hnok(dn+2));
187 if (dn[1] == '\0')
188 return (1);
189 }
190 return (res_hnok(dn));
191}
192
193/*
194 * SOA RNAMEs and RP RNAMEs can have any printable character in their first
195 * label, but the rest of the name has to look like a host name.
196 */
197int
198res_mailok(const char *dn) {
199 int ch, escaped = 0;
200
201 /* "." is a valid missing representation */
202 if (*dn == '\0')
203 return (1);
204
205 /* otherwise <label>.<hostname> */
206 while ((ch = *dn++) != '\0') {
207 if (!domainchar(ch))
208 return (0);
209 if (!escaped && periodchar(ch))
210 break;
211 if (escaped)
212 escaped = 0;
213 else if (bslashchar(ch))
214 escaped = 1;
215 }
216 if (periodchar(ch))
217 return (res_hnok(dn));
218 return (0);
219}
220
221/*
222 * This function is quite liberal, since RFC 1034's character sets are only
223 * recommendations.
224 */
225int
226res_dnok(const char *dn) {
227 int ch;
228
229 while ((ch = *dn++) != '\0')
230 if (!domainchar(ch))
231 return (0);
232 return (1);
233}
234libresolv_hidden_def (res_dnok)
235
236#ifdef BIND_4_COMPAT
237/*
238 * This module must export the following externally-visible symbols:
239 * ___putlong
240 * ___putshort
241 * __getlong
242 * __getshort
243 * Note that one _ comes from C and the others come from us.
244 */
245void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
246libresolv_hidden_def (__putlong)
247void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
248libresolv_hidden_def (__putshort)
249#ifndef __ultrix__
250u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
251u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
252#endif /*__ultrix__*/
253#endif /*BIND_4_COMPAT*/
254
255
256#include <shlib-compat.h>
257
258#if SHLIB_COMPAT(libresolv, GLIBC_2_0, GLIBC_2_2)
259# undef dn_expand
260weak_alias (__dn_expand, dn_expand);
261#endif
262