xref: /titanic_51/usr/src/lib/libresolv2/common/resolv/res_comp.c (revision b76c14595f2dd8b4765b40057467eb8796111fde)
1 /*
2  * Copyright 2003 by Sun Microsystems, Inc. All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (c) 1985, 1993
8  *    The Regents of the University of California.  All rights reserved.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  * 	This product includes software developed by the University of
21  * 	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 /*
40  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
41  *
42  * Permission to use, copy, modify, and distribute this software for any
43  * purpose with or without fee is hereby granted, provided that the above
44  * copyright notice and this permission notice appear in all copies, and that
45  * the name of Digital Equipment Corporation not be used in advertising or
46  * publicity pertaining to distribution of the document or software without
47  * specific, written prior permission.
48  *
49  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
50  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
51  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
52  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
53  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
54  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
55  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
56  * SOFTWARE.
57  */
58 
59 /*
60  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
61  *
62  * Permission to use, copy, modify, and distribute this software for any
63  * purpose with or without fee is hereby granted, provided that the above
64  * copyright notice and this permission notice appear in all copies.
65  *
66  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
67  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
68  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
69  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
70  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
71  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
72  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
73  * SOFTWARE.
74  */
75 
76 #pragma ident	"%Z%%M%	%I%	%E% SMI"
77 
78 #if defined(LIBC_SCCS) && !defined(lint)
79 static const char sccsid[] = "@(#)res_comp.c	8.1 (Berkeley) 6/4/93";
80 static const char rcsid[] = "$Id: res_comp.c,v 8.16 2002/08/07 03:47:34 marka Exp $";
81 #endif /* LIBC_SCCS and not lint */
82 
83 #include "port_before.h"
84 #include <sys/types.h>
85 #include <sys/param.h>
86 #include <netinet/in.h>
87 #include <arpa/nameser.h>
88 #include <ctype.h>
89 #include <resolv.h>
90 #include <stdio.h>
91 #include <string.h>
92 #include <unistd.h>
93 #include "port_after.h"
94 
95 #ifdef	ORIGINAL_ISC_CODE
96 #else
97 #pragma weak	__dn_skipname	=	dn_skipname
98 #pragma weak	__res_dnok	=	res_dnok
99 #pragma weak	__res_hnok	=	res_hnok
100 #pragma weak	__res_mailok	=	res_mailok
101 #pragma weak	__res_ownok	=	res_ownok
102 #endif	/* ORIGINAL_ISC_CODE */
103 /*
104  * Expand compressed domain name 'src' to full domain name.
105  * 'msg' is a pointer to the begining of the message,
106  * 'eom' points to the first location after the message,
107  * 'dst' is a pointer to a buffer of size 'dstsiz' for the result.
108  * 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  * Return the size of the compressed name or -1.
124  * 'length' is the size of the array pointed to by 'comp_dn'.
125  */
126 int
127 dn_comp(const char *src, u_char *dst, int dstsiz,
128 	u_char **dnptrs, u_char **lastdnptr)
129 {
130 	return (ns_name_compress(src, dst, (size_t)dstsiz,
131 				 (const u_char **)dnptrs,
132 				 (const u_char **)lastdnptr));
133 }
134 
135 /*
136  * Skip over a compressed domain name. Return the size or -1.
137  */
138 int
139 dn_skipname(const u_char *ptr, const u_char *eom) {
140 	const u_char *saveptr = ptr;
141 
142 	if (ns_name_skip(&ptr, eom) == -1)
143 		return (-1);
144 	return (ptr - saveptr);
145 }
146 
147 /*
148  * Verify that a domain name uses an acceptable character set.
149  */
150 
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 ppch = '\0', 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 		ppch = pch, 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 RFC 1034'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 #ifdef	ORIGINAL_ISC_CODE
268 #else
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	/* ORIGINAL_ISC_CODE */
278 void __putlong(u_int32_t src, u_char *dst) { ns_put32(src, dst); }
279 void __putshort(u_int16_t src, u_char *dst) { ns_put16(src, dst); }
280 #ifndef __ultrix__
281 u_int32_t _getlong(const u_char *src) { return (ns_get32(src)); }
282 u_int16_t _getshort(const u_char *src) { return (ns_get16(src)); }
283 #endif /*__ultrix__*/
284 #endif /*BIND_4_COMPAT*/
285