xref: /netbsd-src/include/resolv.h (revision fad4c9f71477ae11cea2ee75ec82151ac770a534)
1 /*	$NetBSD: resolv.h,v 1.31 2005/12/26 19:01:47 perry Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1987, 1989
5  *    The Regents of the University of California.  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 University 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 REGENTS 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 REGENTS 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 (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
34  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
35  *
36  * Permission to use, copy, modify, and distribute this software for any
37  * purpose with or without fee is hereby granted, provided that the above
38  * copyright notice and this permission notice appear in all copies.
39  *
40  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
41  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
42  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
43  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
44  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
45  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
46  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
47  */
48 
49 /*
50  *	@(#)resolv.h	8.1 (Berkeley) 6/2/93
51  *	Id: resolv.h,v 1.7.2.11.4.2 2004/06/25 00:41:05 marka Exp
52  */
53 
54 #ifndef _RESOLV_H_
55 #define	_RESOLV_H_
56 
57 #include <sys/param.h>
58 #if (!defined(BSD)) || (BSD < 199306)
59 # include <sys/bitypes.h>
60 #else
61 #include <sys/types.h>
62 #endif
63 #include <sys/cdefs.h>
64 #include <sys/socket.h>
65 #include <stdio.h>
66 #include <arpa/nameser.h>
67 
68 /*
69  * Revision information.  This is the release date in YYYYMMDD format.
70  * It can change every day so the right thing to do with it is use it
71  * in preprocessor commands such as "#if (__RES > 19931104)".  Do not
72  * compare for equality; rather, use it to determine whether your resolver
73  * is new enough to contain a certain feature.
74  */
75 
76 #define	__RES	20030124
77 
78 /*
79  * This used to be defined in res_query.c, now it's in herror.c.
80  * [XXX no it's not.  It's in irs/irs_data.c]
81  * It was
82  * never extern'd by any *.h file before it was placed here.  For thread
83  * aware programs, the last h_errno value set is stored in res->h_errno.
84  *
85  * XXX:	There doesn't seem to be a good reason for exposing RES_SET_H_ERRNO
86  *	(and __h_errno_set) to the public via <resolv.h>.
87  * XXX:	__h_errno_set is really part of IRS, not part of the resolver.
88  *	If somebody wants to build and use a resolver that doesn't use IRS,
89  *	what do they do?  Perhaps something like
90  *		#ifdef WANT_IRS
91  *		# define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
92  *		#else
93  *		# define RES_SET_H_ERRNO(r,x) (h_errno = (r)->res_h_errno = (x))
94  *		#endif
95  */
96 
97 #define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
98 struct __res_state; /* forward */
99 __BEGIN_DECLS
100 void __h_errno_set(struct __res_state *, int);
101 __END_DECLS
102 
103 /*
104  * Resolver configuration file.
105  * Normally not present, but may contain the address of the
106  * initial name server(s) to query and the domain search list.
107  */
108 
109 #ifndef _PATH_RESCONF
110 #define _PATH_RESCONF        "/etc/resolv.conf"
111 #endif
112 
113 typedef enum { res_goahead, res_nextns, res_modified, res_done, res_error }
114 	res_sendhookact;
115 
116 typedef res_sendhookact (*res_send_qhook)(struct sockaddr * const *,
117 					      const u_char **, int *,
118 					      u_char *, int, int *);
119 
120 typedef res_sendhookact (*res_send_rhook)(const struct sockaddr *,
121 					      const u_char *, int, u_char *,
122 					      int, int *);
123 
124 struct res_sym {
125 	int		number;	   /* Identifying number, like T_MX */
126 	const char *	name;	   /* Its symbolic name, like "MX" */
127 	const char *	humanname; /* Its fun name, like "mail exchanger" */
128 };
129 
130 /*
131  * Global defines and variables for resolver stub.
132  */
133 #define	MAXNS			3	/* max # name servers we'll track */
134 #define	MAXDFLSRCH		3	/* # default domain levels to try */
135 #define	MAXDNSRCH		6	/* max # domains in search path */
136 #define	LOCALDOMAINPARTS	2	/* min levels in name that is "local" */
137 
138 #define	RES_TIMEOUT		5	/* min. seconds between retries */
139 #define	MAXRESOLVSORT		10	/* number of net to sort on */
140 #define	RES_MAXNDOTS		15	/* should reflect bit field size */
141 #define	RES_MAXRETRANS		30	/* only for resolv.conf/RES_OPTIONS */
142 #define	RES_MAXRETRY		5	/* only for resolv.conf/RES_OPTIONS */
143 #define	RES_DFLRETRY		2	/* Default #/tries. */
144 #define	RES_MAXTIME		65535	/* Infinity, in milliseconds. */
145 
146 struct __res_state_ext;
147 
148 struct __res_state {
149 	int	retrans;	 	/* retransmission time interval */
150 	int	retry;			/* number of times to retransmit */
151 #ifdef sun
152 	u_int	options;		/* option flags - see below. */
153 #else
154 	u_long	options;		/* option flags - see below. */
155 #endif
156 	int	nscount;		/* number of name servers */
157 	struct sockaddr_in
158 		nsaddr_list[MAXNS];	/* address of name server */
159 #define	nsaddr	nsaddr_list[0]		/* for backward compatibility */
160 	u_short	id;			/* current message id */
161 	char	*dnsrch[MAXDNSRCH+1];	/* components of domain to search */
162 	char	defdname[256];		/* default domain (deprecated) */
163 #ifdef sun
164 	u_int	pfcode;			/* RES_PRF_ flags - see below. */
165 #else
166 	u_long	pfcode;			/* RES_PRF_ flags - see below. */
167 #endif
168 	unsigned ndots:4;		/* threshold for initial abs. query */
169 	unsigned nsort:4;		/* number of elements in sort_list[] */
170 	char	unused[3];
171 	struct {
172 		struct in_addr	addr;
173 		uint32_t	mask;
174 	} sort_list[MAXRESOLVSORT];
175 #ifdef __OLD_RES_STATE
176 	char lookups[4];
177 #else
178 	res_send_qhook qhook;		/* query hook */
179 	res_send_rhook rhook;		/* response hook */
180 	int	res_h_errno;		/* last one set for this context */
181 	int	_vcsock;		/* PRIVATE: for res_send VC i/o */
182 	u_int	_flags;			/* PRIVATE: see below */
183 	u_int	_pad;			/* make _u 64 bit aligned */
184 	union {
185 		/* On an 32-bit arch this means 512b total. */
186 		char	pad[72 - 4*sizeof (int) - 2*sizeof (void *)];
187 		struct {
188 			uint16_t		nscount;
189 			uint16_t		nstimes[MAXNS];	/* ms. */
190 			int			nssocks[MAXNS];
191 			struct __res_state_ext *ext;	/* extention for IPv6 */
192 		} _ext;
193 	} _u;
194 #endif
195 };
196 
197 typedef struct __res_state *res_state;
198 
199 union res_sockaddr_union {
200 	struct sockaddr_in	sin;
201 #ifdef IN6ADDR_ANY_INIT
202 	struct sockaddr_in6	sin6;
203 #endif
204 #ifdef ISC_ALIGN64
205 	int64_t			__align64;	/* 64bit alignment */
206 #else
207 	int32_t			__align32;	/* 32bit alignment */
208 #endif
209 	char			__space[128];   /* max size */
210 };
211 
212 /*
213  * Resolver flags (used to be discrete per-module statics ints).
214  */
215 #define	RES_F_VC	0x00000001	/* socket is TCP */
216 #define	RES_F_CONN	0x00000002	/* socket is connected */
217 #define	RES_F_EDNS0ERR	0x00000004	/* EDNS0 caused errors */
218 #define	RES_F__UNUSED	0x00000008	/* (unused) */
219 #define	RES_F_LASTMASK	0x000000F0	/* ordinal server of last res_nsend */
220 #define	RES_F_LASTSHIFT	4		/* bit position of LASTMASK "flag" */
221 #define	RES_GETLAST(res) (((res)._flags & RES_F_LASTMASK) >> RES_F_LASTSHIFT)
222 
223 /* res_findzonecut2() options */
224 #define	RES_EXHAUSTIVE	0x00000001	/* always do all queries */
225 #define	RES_IPV4ONLY	0x00000002	/* IPv4 only */
226 #define	RES_IPV6ONLY	0x00000004	/* IPv6 only */
227 
228 /*
229  * Resolver options (keep these in synch with res_debug.c, please)
230  */
231 #define RES_INIT	0x00000001	/* address initialized */
232 #define RES_DEBUG	0x00000002	/* print debug messages */
233 #define RES_AAONLY	0x00000004	/* authoritative answers only (!IMPL)*/
234 #define RES_USEVC	0x00000008	/* use virtual circuit */
235 #define RES_PRIMARY	0x00000010	/* query primary server only (!IMPL) */
236 #define RES_IGNTC	0x00000020	/* ignore trucation errors */
237 #define RES_RECURSE	0x00000040	/* recursion desired */
238 #define RES_DEFNAMES	0x00000080	/* use default domain name */
239 #define RES_STAYOPEN	0x00000100	/* Keep TCP socket open */
240 #define RES_DNSRCH	0x00000200	/* search up local domain tree */
241 #define	RES_INSECURE1	0x00000400	/* type 1 security disabled */
242 #define	RES_INSECURE2	0x00000800	/* type 2 security disabled */
243 #define	RES_NOALIASES	0x00001000	/* shuts off HOSTALIASES feature */
244 #define	RES_USE_INET6	0x00002000	/* use/map IPv6 in gethostbyname() */
245 #define RES_ROTATE	0x00004000	/* rotate ns list after each query */
246 #define	RES_NOCHECKNAME	0x00008000	/* do not check names for sanity. */
247 #define	RES_KEEPTSIG	0x00010000	/* do not strip TSIG records */
248 #define	RES_BLAST	0x00020000	/* blast all recursive servers */
249 #define RES_NOTLDQUERY	0x00100000	/* don't unqualified name as a tld */
250 #define RES_USE_DNSSEC	0x00200000	/* use DNSSEC using OK bit in OPT */
251 /* #define RES_DEBUG2	0x00400000 */	/* nslookup internal */
252 /* KAME extensions: use higher bit to avoid conflict with ISC use */
253 #define RES_USE_DNAME	0x10000000	/* use DNAME */
254 #define RES_USE_EDNS0	0x40000000	/* use EDNS0 if configured */
255 #define RES_NO_NIBBLE2	0x80000000	/* disable alternate nibble lookup */
256 
257 #define RES_DEFAULT	(RES_RECURSE | RES_DEFNAMES | \
258 			 RES_DNSRCH | RES_NO_NIBBLE2)
259 
260 /*
261  * Resolver "pfcode" values.  Used by dig.
262  */
263 #define RES_PRF_STATS	0x00000001
264 #define RES_PRF_UPDATE	0x00000002
265 #define RES_PRF_CLASS   0x00000004
266 #define RES_PRF_CMD	0x00000008
267 #define RES_PRF_QUES	0x00000010
268 #define RES_PRF_ANS	0x00000020
269 #define RES_PRF_AUTH	0x00000040
270 #define RES_PRF_ADD	0x00000080
271 #define RES_PRF_HEAD1	0x00000100
272 #define RES_PRF_HEAD2	0x00000200
273 #define RES_PRF_TTLID	0x00000400
274 #define RES_PRF_HEADX	0x00000800
275 #define RES_PRF_QUERY	0x00001000
276 #define RES_PRF_REPLY	0x00002000
277 #define RES_PRF_INIT	0x00004000
278 #define RES_PRF_TRUNC	0x00008000
279 /*			0x00010000	*/
280 
281 /* Things involving an internal (static) resolver context. */
282 __BEGIN_DECLS
283 extern struct __res_state *__res_get_state(void);
284 extern void __res_put_state(struct __res_state *);
285 
286 /*
287  * Source and Binary compatibility; _res will not work properly
288  * with multi-threaded programs.
289  */
290 extern struct __res_state *__res_state(void);
291 #define _res (*__res_state())
292 
293 __END_DECLS
294 
295 #ifndef __BIND_NOSTATIC
296 #define fp_nquery		__fp_nquery
297 #define fp_query		__fp_query
298 #define hostalias		__hostalias
299 #define p_query			__p_query
300 #define res_close		__res_close
301 #define res_opt			__res_opt
302 #define res_isourserver		__res_isourserver
303 #define	res_querydomain		__res_querydomain
304 #define res_send		__res_send
305 #define res_sendsigned		__res_sendsigned
306 
307 #ifdef BIND_RES_POSIX3
308 #define	dn_expand	__dn_expand
309 #define	res_init	__res_init
310 #define	res_query	__res_query
311 #define	res_search	__res_search
312 #define	res_mkquery	__res_mkquery
313 #endif
314 
315 __BEGIN_DECLS
316 void		fp_nquery(const u_char *, int, FILE *);
317 void		fp_query(const u_char *, FILE *);
318 const char *	hostalias(const char *);
319 void		p_query(const u_char *);
320 void		res_close(void);
321 int		res_init(void);
322 int		res_opt(int, u_char *, int, int);
323 int		res_isourserver(const struct sockaddr_in *);
324 int		res_mkquery(int, const char *, int, int, const u_char *,
325 				 int, const u_char *, u_char *, int);
326 int		res_query(const char *, int, int, u_char *, int);
327 int		res_querydomain(const char *, const char *, int, int,
328 				     u_char *, int);
329 int		res_search(const char *, int, int, u_char *, int);
330 int		res_send(const u_char *, int, u_char *, int);
331 int		res_sendsigned(const u_char *, int, ns_tsig_key *,
332 				    u_char *, int);
333 __END_DECLS
334 #endif
335 
336 #if !defined(SHARED_LIBBIND) || defined(LIB)
337 /*
338  * If libbind is a shared object (well, DLL anyway)
339  * these externs break the linker when resolv.h is
340  * included by a lib client (like named)
341  * Make them go away if a client is including this
342  *
343  */
344 extern const struct res_sym __p_key_syms[];
345 extern const struct res_sym __p_cert_syms[];
346 extern const struct res_sym __p_class_syms[];
347 extern const struct res_sym __p_type_syms[];
348 extern const struct res_sym __p_rcode_syms[];
349 #endif /* SHARED_LIBBIND */
350 
351 #define b64_ntop		__b64_ntop
352 #define b64_pton		__b64_pton
353 #define dn_comp			__dn_comp
354 #define dn_count_labels		__dn_count_labels
355 #define dn_skipname		__dn_skipname
356 #define fp_resstat		__fp_resstat
357 #define loc_aton		__loc_aton
358 #define loc_ntoa		__loc_ntoa
359 #define p_cdname		__p_cdname
360 #define p_cdnname		__p_cdnname
361 #define p_class			__p_class
362 #define p_fqname		__p_fqname
363 #define p_fqnname		__p_fqnname
364 #define p_option		__p_option
365 #define p_secstodate		__p_secstodate
366 #define p_section		__p_section
367 #define p_time			__p_time
368 #define p_type			__p_type
369 #define p_rcode			__p_rcode
370 #define p_sockun		__p_sockun
371 #define putlong			__putlong
372 #define putshort		__putshort
373 #define res_dnok		__res_dnok
374 #define res_findzonecut		__res_findzonecut
375 #define res_findzonecut2	__res_findzonecut2
376 #define res_hnok		__res_hnok
377 #define res_hostalias		__res_hostalias
378 #define res_mailok		__res_mailok
379 #define res_nameinquery		__res_nameinquery
380 #define res_nclose		__res_nclose
381 #define res_ninit		__res_ninit
382 #define res_nmkquery		__res_nmkquery
383 #define res_pquery		__res_pquery
384 #define res_nquery		__res_nquery
385 #define res_nquerydomain	__res_nquerydomain
386 #define res_nsearch		__res_nsearch
387 #define res_nsend		__res_nsend
388 #define res_nsendsigned		__res_nsendsigned
389 #define res_nisourserver	__res_nisourserver
390 #define res_ownok		__res_ownok
391 #define res_queriesmatch	__res_queriesmatch
392 #define res_randomid		__res_randomid
393 #define sym_ntop		__sym_ntop
394 #define sym_ntos		__sym_ntos
395 #define sym_ston		__sym_ston
396 #define res_nopt		__res_nopt
397 #define res_ndestroy		__res_ndestroy
398 #define	res_nametoclass		__res_nametoclass
399 #define	res_nametotype		__res_nametotype
400 #define	res_setservers		__res_setservers
401 #define	res_getservers		__res_getservers
402 #define	res_buildprotolist	__res_buildprotolist
403 #define	res_destroyprotolist	__res_destroyprotolist
404 #define	res_destroyservicelist	__res_destroyservicelist
405 #define	res_get_nibblesuffix	__res_get_nibblesuffix
406 #define	res_get_nibblesuffix2	__res_get_nibblesuffix2
407 #define	res_ourserver_p		__res_ourserver_p
408 #define	res_protocolname	__res_protocolname
409 #define	res_protocolnumber	__res_protocolnumber
410 #define	res_send_setqhook	__res_send_setqhook
411 #define	res_send_setrhook	__res_send_setrhook
412 #define	res_servicename		__res_servicename
413 #define	res_servicenumber	__res_servicenumber
414 __BEGIN_DECLS
415 int		res_hnok(const char *);
416 int		res_ownok(const char *);
417 int		res_mailok(const char *);
418 int		res_dnok(const char *);
419 int		sym_ston(const struct res_sym *, const char *, int *);
420 const char *	sym_ntos(const struct res_sym *, int, int *);
421 const char *	sym_ntop(const struct res_sym *, int, int *);
422 int		b64_ntop(u_char const *, size_t, char *, size_t);
423 int		b64_pton(char const *, u_char *, size_t);
424 int		loc_aton(const char *, u_char *);
425 const char *	loc_ntoa(const u_char *, char *);
426 int		dn_skipname(const u_char *, const u_char *);
427 void		putlong(uint32_t, u_char *);
428 void		putshort(uint16_t, u_char *);
429 #ifndef __ultrix__
430 uint16_t	_getshort(const u_char *);
431 uint32_t	_getlong(const u_char *);
432 #endif
433 const char *	p_class(int);
434 const char *	p_time(uint32_t);
435 const char *	p_type(int);
436 const char *	p_rcode(int);
437 const char *	p_sockun(union res_sockaddr_union, char *, size_t);
438 const u_char *	p_cdnname(const u_char *, const u_char *, int, FILE *);
439 const u_char *	p_cdname(const u_char *, const u_char *, FILE *);
440 const u_char *	p_fqnname(const u_char *, const u_char *,
441 			       int, char *, int);
442 const u_char *	p_fqname(const u_char *, const u_char *, FILE *);
443 const char *	p_option(u_long);
444 char *		p_secstodate(u_long);
445 int		dn_count_labels(const char *);
446 int		dn_comp(const char *, u_char *, int, u_char **, u_char **);
447 int		dn_expand(const u_char *, const u_char *, const u_char *,
448 			       char *, int);
449 u_int		res_randomid(void);
450 int		res_nameinquery(const char *, int, int, const u_char *,
451 				     const u_char *);
452 int		res_queriesmatch(const u_char *, const u_char *,
453 				      const u_char *, const u_char *);
454 const char *	p_section(int, int);
455 /* Things involving a resolver context. */
456 int		res_ninit(res_state);
457 int		res_nisourserver(const res_state, const struct sockaddr_in *);
458 void		fp_resstat(const res_state, FILE *);
459 void		res_pquery(const res_state, const u_char *, int, FILE *);
460 const char *	res_hostalias(const res_state, const char *, char *, size_t);
461 int		res_nquery(res_state, const char *, int, int, u_char *, int);
462 int		res_nsearch(res_state, const char *, int, int, u_char *, int);
463 int		res_nquerydomain(res_state, const char *, const char *,
464 				      int, int, u_char *, int);
465 int		res_nmkquery(res_state, int, const char *, int, int,
466 				  const u_char *, int, const u_char *,
467 				  u_char *, int);
468 int		res_nsend(res_state, const u_char *, int, u_char *, int);
469 int		res_nsendsigned(res_state, const u_char *, int,
470 				     ns_tsig_key *, u_char *, int);
471 int		res_findzonecut(res_state, const char *, ns_class, int,
472 				     char *, size_t, struct in_addr *, int);
473 int		res_findzonecut2(res_state, const char *, ns_class, int,
474 				      char *, size_t,
475 				      union res_sockaddr_union *, int);
476 void		res_nclose(res_state);
477 int		res_nopt(res_state, int, u_char *, int, int);
478 void		res_send_setqhook(res_send_qhook);
479 void		res_send_setrhook(res_send_rhook);
480 int		__res_vinit(res_state, int);
481 void		res_destroyservicelist(void);
482 const char *	res_servicename(uint16_t, const char *);
483 const char *	res_protocolname(int);
484 void		res_destroyprotolist(void);
485 void		res_buildprotolist(void);
486 const char *	res_get_nibblesuffix(res_state);
487 const char *	res_get_nibblesuffix2(res_state);
488 void		res_ndestroy(res_state);
489 uint16_t	res_nametoclass(const char *, int *);
490 uint16_t	res_nametotype(const char *, int *);
491 void		res_setservers(res_state,
492 				    const union res_sockaddr_union *, int);
493 int		res_getservers(res_state,
494 				    union res_sockaddr_union *, int);
495 __END_DECLS
496 
497 #endif /* !_RESOLV_H_ */
498