1 /*	$OpenBSD: resolv.h,v 1.23 2021/11/22 20:18:27 jca Exp $	*/
2 
3 /*
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * 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 project 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 PROJECT 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 PROJECT 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  * ++Copyright++ 1983, 1987, 1989, 1993
34  * -
35  * Copyright (c) 1983, 1987, 1989, 1993
36  *    The Regents of the University of California.  All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  * -
62  * Portions Copyright (c) 1993 by Digital Equipment Corporation.
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, and that
67  * the name of Digital Equipment Corporation not be used in advertising or
68  * publicity pertaining to distribution of the document or software without
69  * specific, written prior permission.
70  *
71  * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
72  * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
73  * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT
74  * CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
75  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
76  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
77  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
78  * SOFTWARE.
79  * -
80  * --Copyright--
81  */
82 
83 /*
84  *	@(#)resolv.h	8.1 (Berkeley) 6/2/93
85  *	$From: resolv.h,v 8.17 1996/11/26 10:11:20 vixie Exp $
86  */
87 
88 #ifndef _RESOLV_H_
89 #define	_RESOLV_H_
90 
91 #include <sys/types.h>
92 #include <sys/socket.h>
93 #include <stdio.h>
94 
95 /*
96  * Revision information.  This is the release date in YYYYMMDD format.
97  * It can change every day so the right thing to do with it is use it
98  * in preprocessor commands such as "#if (__RES > 19931104)".  Do not
99  * compare for equality; rather, use it to determine whether your resolver
100  * is new enough to contain a certain feature.
101  */
102 
103 #define	__RES	19960801
104 
105 /*
106  * Resolver configuration file.
107  * Normally not present, but may contain the address of the
108  * initial name server(s) to query and the domain search list.
109  */
110 
111 #ifndef _PATH_RESCONF
112 #define _PATH_RESCONF        "/etc/resolv.conf"
113 #endif
114 
115 /*
116  * Global defines and variables for resolver stub.
117  */
118 #define	MAXNS			3	/* max # name servers we'll track */
119 #define	MAXDFLSRCH		3	/* # default domain levels to try */
120 #define	MAXDNSRCH		6	/* max # domains in search path */
121 #define	LOCALDOMAINPARTS	2	/* min levels in name that is "local" */
122 #define MAXDNSLUS		4	/* max # of host lookup types */
123 
124 #define	RES_TIMEOUT		5	/* min. seconds between retries */
125 #define	MAXRESOLVSORT		10	/* number of net to sort on */
126 #define	RES_MAXNDOTS		15	/* should reflect bit field size */
127 
128 struct __res_state {
129 	int	retrans;	 	/* retransmission time interval */
130 	int	retry;			/* number of times to retransmit */
131 	unsigned int	options;	/* option flags - see below. */
132 	int	nscount;		/* number of name servers */
133 	int	family[2];		/* specifies which address
134 					 * families will be queried and
135 					 * in which order */
136 	struct sockaddr_in
137 		nsaddr_list[MAXNS];	/* address of name server */
138 #define	nsaddr	nsaddr_list[0]		/* for backward compatibility */
139 	unsigned short	id;		/* current message id */
140 	char	*dnsrch[MAXDNSRCH+1];	/* components of domain to search */
141 	char	defdname[256];		/* default domain (deprecated) */
142 	unsigned int	pfcode;		/* RES_PRF_ flags - see below. */
143 	unsigned ndots:4;		/* threshold for initial abs. query */
144 	unsigned nsort:4;		/* number of elements in sort_list[] */
145 	char	unused[3];
146 	struct {
147 		struct in_addr	addr;
148 		u_int32_t	mask;
149 	} sort_list[MAXRESOLVSORT];
150 	char    lookups[MAXDNSLUS];
151 	struct { time_t __res_sec; long __res_nsec; } restimespec;
152 	time_t	reschktime;
153 };
154 
155 #if 1 /* INET6 */
156 /*
157  * replacement of __res_state, separated to keep binary compatibility.
158  */
159 struct __res_state_ext {
160 	struct sockaddr_storage nsaddr_list[MAXNS];
161 	struct {
162 		int	af;		/* address family for addr, mask */
163 		union {
164 			struct in_addr ina;
165 			struct in6_addr in6a;
166 		} addr, mask;
167 	} sort_list[MAXRESOLVSORT];
168 };
169 #endif
170 
171 
172 /*
173  * Resolver options (keep these in synch with res_debug.c, please)
174  */
175 #define RES_INIT	0x00000001	/* address initialized */
176 #define RES_DEBUG	0x00000002	/* print debug messages */
177 #define RES_AAONLY	0x00000004	/* authoritative answers only (!IMPL)*/
178 #define RES_USEVC	0x00000008	/* use virtual circuit */
179 #define RES_PRIMARY	0x00000010	/* query primary server only (!IMPL) */
180 #define RES_IGNTC	0x00000020	/* ignore trucation errors */
181 #define RES_RECURSE	0x00000040	/* recursion desired */
182 #define RES_DEFNAMES	0x00000080	/* use default domain name */
183 #define RES_STAYOPEN	0x00000100	/* Keep TCP socket open */
184 #define RES_DNSRCH	0x00000200	/* search up local domain tree */
185 #define	RES_INSECURE1	0x00000400	/* type 1 security disabled */
186 #define	RES_INSECURE2	0x00000800	/* type 2 security disabled */
187 #define	RES_NOALIASES	0x00001000	/* shuts off HOSTALIASES feature */
188 #define	RES_USE_INET6	0x00002000	/* use/map IPv6 in gethostbyname() */
189 /* KAME extensions: use higher bit to avoid conflict with ISC use */
190 #define	RES_USE_EDNS0	0x40000000	/* use EDNS0 */
191 /* DNSSEC extensions: use higher bit to avoid conflict with ISC use */
192 #define	RES_USE_DNSSEC	0x20000000	/* use DNSSEC using OK bit in OPT */
193 #define	RES_USE_CD	0x10000000	/* set Checking Disabled flag */
194 #define	RES_TRUSTAD	0x80000000	/* Request AD, keep it in responses. */
195 
196 #define RES_DEFAULT	(RES_RECURSE | RES_DEFNAMES | RES_DNSRCH)
197 
198 /*
199  * Resolver "pfcode" values.  Used by dig.
200  */
201 #define RES_PRF_STATS	0x00000001
202 /*			0x00000002	*/
203 #define RES_PRF_CLASS   0x00000004
204 #define RES_PRF_CMD	0x00000008
205 #define RES_PRF_QUES	0x00000010
206 #define RES_PRF_ANS	0x00000020
207 #define RES_PRF_AUTH	0x00000040
208 #define RES_PRF_ADD	0x00000080
209 #define RES_PRF_HEAD1	0x00000100
210 #define RES_PRF_HEAD2	0x00000200
211 #define RES_PRF_TTLID	0x00000400
212 #define RES_PRF_HEADX	0x00000800
213 #define RES_PRF_QUERY	0x00001000
214 #define RES_PRF_REPLY	0x00002000
215 #define RES_PRF_INIT    0x00004000
216 /*			0x00008000	*/
217 
218 /* hooks are still experimental as of 4.9.2 */
219 typedef enum { res_goahead, res_nextns, res_modified, res_done, res_error }
220 	res_sendhookact;
221 
222 typedef res_sendhookact (*res_send_qhook)(struct sockaddr_in * const *ns,
223 					      const unsigned char **query,
224 					      int *querylen,
225 					      unsigned char *ans,
226 					      int anssiz,
227 					      int *resplen);
228 
229 typedef res_sendhookact (*res_send_rhook)(const struct sockaddr_in *ns,
230 					      const unsigned char *query,
231 					      int querylen,
232 					      unsigned char *ans,
233 					      int anssiz,
234 					      int *resplen);
235 
236 struct res_sym {
237 	int	number;		/* Identifying number, like T_MX */
238 	char *	name;		/* Its symbolic name, like "MX" */
239 	char *	humanname;	/* Its fun name, like "mail exchanger" */
240 };
241 
242 extern struct __res_state _res;
243 #if 1 /* INET6 */
244 extern struct __res_state_ext _res_ext;
245 #endif
246 extern const struct res_sym __p_class_syms[];
247 extern const struct res_sym __p_type_syms[];
248 
249 /* Private routines shared between libc/net, named, nslookup and others. */
250 #define	res_hnok	__res_hnok
251 #define	res_ownok	__res_ownok
252 #define	res_mailok	__res_mailok
253 #define	res_dnok	__res_dnok
254 #define	sym_ntos	__sym_ntos
255 #define b64_ntop	__b64_ntop
256 #define	b64_pton	__b64_pton
257 #define	dn_skipname	__dn_skipname
258 #define	putlong		__putlong
259 #define	putshort	__putshort
260 #define p_class		__p_class
261 #define p_type		__p_type
262 #define	dn_count_labels	__dn_count_labels
263 #define	dn_comp		__dn_comp
264 #define	res_randomid	__res_randomid
265 #define	res_send	__res_send
266 #define	res_opt		__res_opt
267 
268 #ifdef BIND_RES_POSIX3
269 #define	dn_expand	__dn_expand
270 #define	res_init	__res_init
271 #define	res_query	__res_query
272 #define	res_search	__res_search
273 #define	res_querydomain	__res_querydomain
274 #define	res_mkquery	__res_mkquery
275 #endif
276 
277 __BEGIN_DECLS
278 int			res_hnok(const char *);
279 int			res_ownok(const char *);
280 int			res_mailok(const char *);
281 int			res_dnok(const char *);
282 const char *		sym_ntos(const struct res_sym *, int, int *);
283 int			b64_ntop(unsigned char const *, size_t, char *, size_t);
284 int			b64_pton(char const *, unsigned char *, size_t);
285 int			dn_skipname(const unsigned char *,
286 			    const unsigned char *);
287 void			putlong(u_int32_t, unsigned char *);
288 void			putshort(u_int16_t, unsigned char *);
289 const char *		p_class(int);
290 const char *		p_type(int);
291 int			dn_comp(const char *, unsigned char *, int,
292 			    unsigned char **, unsigned char **);
293 int			dn_expand(const unsigned char *, const unsigned char *,
294 			    const unsigned char *, char *, int);
295 int			res_init(void);
296 unsigned int		res_randomid(void);
297 int			res_query(const char *, int, int, unsigned char *, int)
298 			__attribute__((__bounded__(__string__,4,5)));
299 int			res_search(const char *, int, int, unsigned char *, int)
300 			    __attribute__((__bounded__(__string__,4,5)));
301 int			res_querydomain(const char *, const char *, int, int,
302 			    unsigned char *, int)
303 			__attribute__((__bounded__(__string__,5,6)));
304 int			res_mkquery(int, const char *, int, int,
305 			    const unsigned char *, int, const unsigned char *,
306 			    unsigned char *, int)
307 			__attribute__((__bounded__(__string__,5,6)))
308 			__attribute__((__bounded__(__string__,8,9)));
309 int			res_send(const unsigned char *, int, unsigned char *,
310 			    int)
311 			__attribute__((__bounded__(__string__,3,4)));
312 __END_DECLS
313 
314 #endif /* !_RESOLV_H_ */
315