1 /*
2  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 
7 /*
8  * Copyright (c) 1985, 1993
9  *    The Regents of the University of California.  All rights reserved.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. All advertising materials mentioning features or use of this software
20  *    must display the following acknowledgement:
21  * 	This product includes software developed by the University of
22  * 	California, Berkeley and its contributors.
23  * 4. Neither the name of the University nor the names of its contributors
24  *    may be used to endorse or promote products derived from this software
25  *    without specific prior written permission.
26  *
27  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37  * SUCH DAMAGE.
38  */
39 
40 /*
41  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
42  *
43  * Permission to use, copy, modify, and distribute this software for any
44  * purpose with or without fee is hereby granted, provided that the above
45  * copyright notice and this permission notice appear in all copies, and that
46  * the name of Digital Equipment Corporation not be used in advertising or
47  * publicity pertaining to distribution of the document or software without
48  * specific, written prior permission.
49  *
50  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
51  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
52  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
53  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
54  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
55  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
56  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
57  * SOFTWARE.
58  */
59 
60 /*
61  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
62  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
63  *
64  * Permission to use, copy, modify, and distribute this software for any
65  * purpose with or without fee is hereby granted, provided that the above
66  * copyright notice and this permission notice appear in all copies.
67  *
68  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
69  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
70  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
71  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
72  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
73  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
74  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
75  */
76 
77 #if defined(LIBC_SCCS) && !defined(lint)
78 static const char sccsid[] = "@(#)res_comp.c	8.1 (Berkeley) 6/4/93";
79 static const char rcsid[] = "$Id: res_comp.c,v 1.5 2005/07/28 06:51:50 marka Exp $";
80 #endif /* LIBC_SCCS and not lint */
81 
82 #include "port_before.h"
83 #include <sys/types.h>
84 #include <sys/param.h>
85 #include <netinet/in.h>
86 #include <arpa/nameser.h>
87 #include <ctype.h>
88 #include <resolv.h>
89 #include <stdio.h>
90 #include <string.h>
91 #include <unistd.h>
92 #include "port_after.h"
93 
94 #ifndef	ORIGINAL_ISC_CODE
95 #pragma weak	__dn_skipname	=	dn_skipname
96 #pragma weak	__res_dnok	=	res_dnok
97 #pragma weak	__res_hnok	=	res_hnok
98 #pragma weak	__res_mailok	=	res_mailok
99 #pragma weak	__res_ownok	=	res_ownok
100 #endif	/* ORIGINAL_ISC_CODE */
101 
102 /*%
103  * Expand compressed domain name 'src' to full domain name.
104  *
105  * \li 'msg' is a pointer to the begining of the message,
106  * \li 'eom' points to the first location after the message,
107  * \li 'dst' is a pointer to a buffer of size 'dstsiz' for the result.
108  * \li Return size of compressed name or -1 if there was an error.
109  */
110 int
111 dn_expand(const u_char *msg, const u_char *eom, const u_char *src,
112 	  char *dst, int dstsiz)
113 {
114 	int n = ns_name_uncompress(msg, eom, src, dst, (size_t)dstsiz);
115 
116 	if (n > 0 && dst[0] == '.')
117 		dst[0] = '\0';
118 	return (n);
119 }
120 
121 /*%
122  * Pack domain name 'exp_dn' in presentation form into 'comp_dn'.
123  *
124  * \li Return the size of the compressed name or -1.
125  * \li 'length' is the size of the array pointed to by 'comp_dn'.
126  */
127 int
128 dn_comp(const char *src, u_char *dst, int dstsiz,
129 	u_char **dnptrs, u_char **lastdnptr)
130 {
131 	return (ns_name_compress(src, dst, (size_t)dstsiz,
132 				 (const u_char **)dnptrs,
133 				 (const u_char **)lastdnptr));
134 }
135 
136 
137 /*%
138  * Skip over a compressed domain name. Return the size or -1.
139  */
140 int
141 dn_skipname(const u_char *ptr, const u_char *eom) {
142 	const u_char *saveptr = ptr;
143 
144 	if (ns_name_skip(&ptr, eom) == -1)
145 		return (-1);
146 	return (ptr - saveptr);
147 }
148 
149 /*%
150  * Verify that a domain name uses an acceptable character set.
151  *
152  * Note the conspicuous absence of ctype macros in these definitions.  On
153  * non-ASCII hosts, we can't depend on string literals or ctype macros to
154  * tell us anything about network-format data.  The rest of the BIND system
155  * is not careful about this, but for some reason, we're doing it right here.
156  */
157 #define PERIOD 0x2e
158 #define	hyphenchar(c) ((c) == 0x2d)
159 #define bslashchar(c) ((c) == 0x5c)
160 #ifdef	SUNW_HNOK_UNDERSCORE
161 #define	underscorechar(c)	((c) == 0x5f)
162 #endif	/* SUNW_HNOK_UNDERSCORE */
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 #ifdef	SUNW_HNOK_UNDERSCORE
171 #define middlechar(c) (borderchar(c) || hyphenchar(c) || underscorechar(c))
172 #else
173 #define middlechar(c) (borderchar(c) || hyphenchar(c))
174 #endif	/* SUNW_HNOK_UNDERSCORE */
175 #define	domainchar(c) ((c) > 0x20 && (c) < 0x7f)
176 
177 int
178 res_hnok(const char *dn) {
179 	int pch = PERIOD, ch = *dn++;
180 
181 	while (ch != '\0') {
182 		int nch = *dn++;
183 
184 		if (periodchar(ch)) {
185 			(void)NULL;
186 		} else if (periodchar(pch)) {
187 			if (!borderchar(ch))
188 				return (0);
189 		} else if (periodchar(nch) || nch == '\0') {
190 			if (!borderchar(ch))
191 				return (0);
192 		} else {
193 			if (!middlechar(ch))
194 				return (0);
195 		}
196 		pch = ch, ch = nch;
197 	}
198 	return (1);
199 }
200 
201 /*%
202  * hostname-like (A, MX, WKS) owners can have "*" as their first label
203  * but must otherwise be as a host name.
204  */
205 int
206 res_ownok(const char *dn) {
207 	if (asterchar(dn[0])) {
208 		if (periodchar(dn[1]))
209 			return (res_hnok(dn+2));
210 		if (dn[1] == '\0')
211 			return (1);
212 	}
213 	return (res_hnok(dn));
214 }
215 
216 /*%
217  * SOA RNAMEs and RP RNAMEs can have any printable character in their first
218  * label, but the rest of the name has to look like a host name.
219  */
220 int
221 res_mailok(const char *dn) {
222 	int ch, escaped = 0;
223 
224 	/* "." is a valid missing representation */
225 	if (*dn == '\0')
226 		return (1);
227 
228 	/* otherwise <label>.<hostname> */
229 	while ((ch = *dn++) != '\0') {
230 		if (!domainchar(ch))
231 			return (0);
232 		if (!escaped && periodchar(ch))
233 			break;
234 		if (escaped)
235 			escaped = 0;
236 		else if (bslashchar(ch))
237 			escaped = 1;
238 	}
239 	if (periodchar(ch))
240 		return (res_hnok(dn));
241 	return (0);
242 }
243 
244 /*%
245  * This function is quite liberal, since RFC1034's character sets are only
246  * recommendations.
247  */
248 int
249 res_dnok(const char *dn) {
250 	int ch;
251 
252 	while ((ch = *dn++) != '\0')
253 		if (!domainchar(ch))
254 			return (0);
255 	return (1);
256 }
257 
258 #ifdef BIND_4_COMPAT
259 /*%
260  * This module must export the following externally-visible symbols:
261  *	___putlong
262  *	___putshort
263  *	__getlong
264  *	__getshort
265  * Note that one _ comes from C and the others come from us.
266  */
267 
268 #ifdef SOLARIS2
269 #ifdef  __putlong
270 #undef  __putlong
271 #endif
272 #ifdef  __putshort
273 #undef  __putshort
274 #endif
275 #pragma weak    putlong         =       __putlong
276 #pragma weak    putshort        =       __putshort
277 #endif /* SOLARIS2 */
278 
279 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
280 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
281 #ifndef __ultrix__
282 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
283 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
284 #endif /*__ultrix__*/
285 #endif /*BIND_4_COMPAT*/
286 
287 /*! \file */
288