xref: /freebsd/include/resolv.h (revision bfe691b2f75de2224c7ceb304ebcdef2b42d4179)
1 /*
2  * Copyright (c) 1983, 1987, 1989
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  * 	This product includes software developed by the University of
16  * 	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 /*
35  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
36  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
37  *
38  * Permission to use, copy, modify, and distribute this software for any
39  * purpose with or without fee is hereby granted, provided that the above
40  * copyright notice and this permission notice appear in all copies.
41  *
42  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
43  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
44  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
45  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
46  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
47  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
48  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
49  */
50 
51 /*
52  *	@(#)resolv.h	8.1 (Berkeley) 6/2/93
53  *	$Id: resolv.h,v 1.7.2.11.4.3 2005/08/25 04:44:13 marka Exp $
54  * $FreeBSD$
55  */
56 
57 #ifndef _RESOLV_H_
58 #define	_RESOLV_H_
59 
60 #include <sys/param.h>
61 #include <sys/types.h>
62 #include <sys/cdefs.h>
63 #include <sys/socket.h>
64 #include <stdio.h>
65 #include <arpa/nameser.h>
66 
67 /*
68  * Revision information.  This is the release date in YYYYMMDD format.
69  * It can change every day so the right thing to do with it is use it
70  * in preprocessor commands such as "#if (__RES > 19931104)".  Do not
71  * compare for equality; rather, use it to determine whether your resolver
72  * is new enough to contain a certain feature.
73  */
74 
75 #define	__RES	20030124
76 
77 /*
78  * This used to be defined in res_query.c, now it's in herror.c.
79  * [XXX no it's not.  It's in irs/irs_data.c]
80  * It was
81  * never extern'd by any *.h file before it was placed here.  For thread
82  * aware programs, the last h_errno value set is stored in res->h_errno.
83  *
84  * XXX:	There doesn't seem to be a good reason for exposing RES_SET_H_ERRNO
85  *	(and __h_errno_set) to the public via <resolv.h>.
86  * XXX:	__h_errno_set is really part of IRS, not part of the resolver.
87  *	If somebody wants to build and use a resolver that doesn't use IRS,
88  *	what do they do?  Perhaps something like
89  *		#ifdef WANT_IRS
90  *		# define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
91  *		#else
92  *		# define RES_SET_H_ERRNO(r,x) (h_errno = (r)->res_h_errno = (x))
93  *		#endif
94  */
95 
96 #define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
97 struct __res_state; /* forward */
98 __BEGIN_DECLS
99 void __h_errno_set(struct __res_state *, int);
100 __END_DECLS
101 
102 /*
103  * Resolver configuration file.
104  * Normally not present, but may contain the address of the
105  * initial name server(s) to query and the domain search list.
106  */
107 
108 #ifndef _PATH_RESCONF
109 #define	_PATH_RESCONF        "/etc/resolv.conf"
110 #endif
111 
112 typedef enum { res_goahead, res_nextns, res_modified, res_done, res_error }
113 	res_sendhookact;
114 
115 typedef res_sendhookact (*res_send_qhook)(struct sockaddr * const *,
116 					  const u_char **, int *,
117 					  u_char *, int, int *);
118 
119 typedef res_sendhookact (*res_send_rhook)(const struct sockaddr *,
120 					  const u_char *, int, u_char *,
121 					  int, int *);
122 
123 struct res_sym {
124 	int		number;	   /* Identifying number, like T_MX */
125 	const char *	name;	   /* Its symbolic name, like "MX" */
126 	const char *	humanname; /* Its fun name, like "mail exchanger" */
127 };
128 
129 /*
130  * Global defines and variables for resolver stub.
131  */
132 #define	MAXNS			3	/* max # name servers we'll track */
133 #define	MAXDFLSRCH		3	/* # default domain levels to try */
134 #define	MAXDNSRCH		6	/* max # domains in search path */
135 #define	LOCALDOMAINPARTS	2	/* min levels in name that is "local" */
136 
137 #define	RES_TIMEOUT		5	/* min. seconds between retries */
138 #define	MAXRESOLVSORT		10	/* number of net to sort on */
139 #define	RES_MAXNDOTS		15	/* should reflect bit field size */
140 #define	RES_MAXRETRANS		30	/* only for resolv.conf/RES_OPTIONS */
141 #define	RES_MAXRETRY		5	/* only for resolv.conf/RES_OPTIONS */
142 #define	RES_DFLRETRY		2	/* Default #/tries. */
143 #define	RES_MAXTIME		65535	/* Infinity, in milliseconds. */
144 
145 struct __res_state_ext;
146 
147 struct __res_state {
148 	int	retrans;	 	/* retransmission time interval */
149 	int	retry;			/* number of times to retransmit */
150 	/*
151 	 * XXX: If `sun' is defined, `options' and `pfcode' are
152 	 * defined as u_int in original BIND9 distribution.  However,
153 	 * it breaks binary backward compatibility against FreeBSD's
154 	 * resolver.  So, we changed not to see `sun'.
155 	 */
156 #if defined(sun) && 0
157 	u_int	options;		/* option flags - see below. */
158 #else
159 	u_long	options;		/* option flags - see below. */
160 #endif
161 	int	nscount;		/* number of name servers */
162 	struct sockaddr_in
163 		nsaddr_list[MAXNS];	/* address of name server */
164 #define	nsaddr	nsaddr_list[0]		/* for backward compatibility */
165 	u_short	id;			/* current message id */
166 	char	*dnsrch[MAXDNSRCH+1];	/* components of domain to search */
167 	char	defdname[256];		/* default domain (deprecated) */
168 #if defined(sun) && 0
169 	u_int	pfcode;			/* RES_PRF_ flags - see below. */
170 #else
171 	u_long	pfcode;			/* RES_PRF_ flags - see below. */
172 #endif
173 	unsigned ndots:4;		/* threshold for initial abs. query */
174 	unsigned nsort:4;		/* number of elements in sort_list[] */
175 	char	unused[3];
176 	struct {
177 		struct in_addr	addr;
178 		u_int32_t	mask;
179 	} sort_list[MAXRESOLVSORT];
180 	res_send_qhook qhook;		/* query hook */
181 	res_send_rhook rhook;		/* response hook */
182 	int	res_h_errno;		/* last one set for this context */
183 	int	_vcsock;		/* PRIVATE: for res_send VC i/o */
184 	u_int	_flags;			/* PRIVATE: see below */
185 	u_int	_pad;			/* make _u 64 bit aligned */
186 	union {
187 		/* On an 32-bit arch this means 512b total. */
188 		char	pad[72 - 4*sizeof (int) - 2*sizeof (void *)];
189 		struct {
190 			u_int16_t		nscount;
191 			u_int16_t		nstimes[MAXNS];	/* ms. */
192 			int			nssocks[MAXNS];
193 			struct __res_state_ext *ext;	/* extention for IPv6 */
194 		} _ext;
195 	} _u;
196 };
197 
198 typedef struct __res_state *res_state;
199 
200 union res_sockaddr_union {
201 	struct sockaddr_in	sin;
202 #ifdef IN6ADDR_ANY_INIT
203 	struct sockaddr_in6	sin6;
204 #endif
205 #ifdef ISC_ALIGN64
206 	int64_t			__align64;	/* 64bit alignment */
207 #else
208 	int32_t			__align32;	/* 32bit alignment */
209 #endif
210 	char			__space[128];   /* max size */
211 };
212 
213 /*
214  * Resolver flags (used to be discrete per-module statics ints).
215  */
216 #define	RES_F_VC	0x00000001	/* socket is TCP */
217 #define	RES_F_CONN	0x00000002	/* socket is connected */
218 #define	RES_F_EDNS0ERR	0x00000004	/* EDNS0 caused errors */
219 #define	RES_F__UNUSED	0x00000008	/* (unused) */
220 #define	RES_F_LASTMASK	0x000000F0	/* ordinal server of last res_nsend */
221 #define	RES_F_LASTSHIFT	4		/* bit position of LASTMASK "flag" */
222 #define	RES_GETLAST(res) (((res)._flags & RES_F_LASTMASK) >> RES_F_LASTSHIFT)
223 
224 /* res_findzonecut2() options */
225 #define	RES_EXHAUSTIVE	0x00000001	/* always do all queries */
226 #define	RES_IPV4ONLY	0x00000002	/* IPv4 only */
227 #define	RES_IPV6ONLY	0x00000004	/* IPv6 only */
228 
229 /*
230  * Resolver options (keep these in synch with res_debug.c, please)
231  */
232 #define RES_INIT	0x00000001	/* address initialized */
233 #define RES_DEBUG	0x00000002	/* print debug messages */
234 #define RES_AAONLY	0x00000004	/* authoritative answers only (!IMPL)*/
235 #define RES_USEVC	0x00000008	/* use virtual circuit */
236 #define RES_PRIMARY	0x00000010	/* query primary server only (!IMPL) */
237 #define RES_IGNTC	0x00000020	/* ignore truncation errors */
238 #define RES_RECURSE	0x00000040	/* recursion desired */
239 #define RES_DEFNAMES	0x00000080	/* use default domain name */
240 #define RES_STAYOPEN	0x00000100	/* Keep TCP socket open */
241 #define RES_DNSRCH	0x00000200	/* search up local domain tree */
242 #define	RES_INSECURE1	0x00000400	/* type 1 security disabled */
243 #define	RES_INSECURE2	0x00000800	/* type 2 security disabled */
244 #define	RES_NOALIASES	0x00001000	/* shuts off HOSTALIASES feature */
245 #define	RES_USE_INET6	0x00002000	/* use/map IPv6 in gethostbyname() */
246 #define RES_ROTATE	0x00004000	/* rotate ns list after each query */
247 #define	RES_NOCHECKNAME	0x00008000	/* do not check names for sanity. */
248 #define	RES_KEEPTSIG	0x00010000	/* do not strip TSIG records */
249 #define	RES_BLAST	0x00020000	/* blast all recursive servers */
250 #define RES_NOTLDQUERY	0x00100000	/* don't unqualified name as a tld */
251 #define RES_USE_DNSSEC	0x00200000	/* use DNSSEC using OK bit in OPT */
252 /* #define RES_DEBUG2	0x00400000 */	/* nslookup internal */
253 /* KAME extensions: use higher bit to avoid conflict with ISC use */
254 #define RES_USE_DNAME	0x10000000	/* use DNAME */
255 #define RES_USE_EDNS0	0x40000000	/* use EDNS0 if configured */
256 #define RES_NO_NIBBLE2	0x80000000	/* disable alternate nibble lookup */
257 
258 #define RES_DEFAULT	(RES_RECURSE | RES_DEFNAMES | \
259 			 RES_DNSRCH | RES_NO_NIBBLE2)
260 
261 /*
262  * Resolver "pfcode" values.  Used by dig.
263  */
264 #define	RES_PRF_STATS	0x00000001
265 #define	RES_PRF_UPDATE	0x00000002
266 #define	RES_PRF_CLASS   0x00000004
267 #define	RES_PRF_CMD	0x00000008
268 #define	RES_PRF_QUES	0x00000010
269 #define	RES_PRF_ANS	0x00000020
270 #define	RES_PRF_AUTH	0x00000040
271 #define	RES_PRF_ADD	0x00000080
272 #define	RES_PRF_HEAD1	0x00000100
273 #define	RES_PRF_HEAD2	0x00000200
274 #define	RES_PRF_TTLID	0x00000400
275 #define	RES_PRF_HEADX	0x00000800
276 #define	RES_PRF_QUERY	0x00001000
277 #define	RES_PRF_REPLY	0x00002000
278 #define	RES_PRF_INIT	0x00004000
279 #define	RES_PRF_TRUNC	0x00008000
280 /*			0x00010000	*/
281 
282 /* Things involving an internal (static) resolver context. */
283 __BEGIN_DECLS
284 extern struct __res_state *__res_state(void);
285 __END_DECLS
286 #define _res (*__res_state())
287 
288 #ifndef __BIND_NOSTATIC
289 #define fp_nquery		__fp_nquery
290 #define fp_query		__fp_query
291 #define hostalias		__hostalias
292 #define p_query			__p_query
293 #define res_close		__res_close
294 #define res_init		__res_init
295 #define res_isourserver		__res_isourserver
296 #define res_mkquery		__res_mkquery
297 #define res_opt			__res_opt
298 #define res_query		__res_query
299 #define res_querydomain		__res_querydomain
300 #define res_search		__res_search
301 #define res_send		__res_send
302 #define res_sendsigned		__res_sendsigned
303 
304 __BEGIN_DECLS
305 void		fp_nquery(const u_char *, int, FILE *);
306 void		fp_query(const u_char *, FILE *);
307 const char *	hostalias(const char *);
308 void		p_query(const u_char *);
309 void		res_close(void);
310 int		res_init(void);
311 int		res_isourserver(const struct sockaddr_in *);
312 int		res_mkquery(int, const char *, int, int, const u_char *,
313 				 int, const u_char *, u_char *, int);
314 int		res_opt(int, u_char *, int, int);
315 int		res_query(const char *, int, int, u_char *, int);
316 int		res_querydomain(const char *, const char *, int, int,
317 				     u_char *, int);
318 int		res_search(const char *, int, int, u_char *, int);
319 int		res_send(const u_char *, int, u_char *, int);
320 int		res_sendsigned(const u_char *, int, ns_tsig_key *,
321 				    u_char *, int);
322 __END_DECLS
323 #endif
324 
325 #if !defined(SHARED_LIBBIND) || defined(LIB)
326 /*
327  * If libbind is a shared object (well, DLL anyway)
328  * these externs break the linker when resolv.h is
329  * included by a lib client (like named)
330  * Make them go away if a client is including this
331  *
332  */
333 extern const struct res_sym __p_key_syms[];
334 extern const struct res_sym __p_cert_syms[];
335 extern const struct res_sym __p_class_syms[];
336 extern const struct res_sym __p_type_syms[];
337 extern const struct res_sym __p_rcode_syms[];
338 #endif /* SHARED_LIBBIND */
339 
340 #define b64_ntop		__b64_ntop
341 #define b64_pton		__b64_pton
342 #define dn_comp			__dn_comp
343 #define dn_count_labels		__dn_count_labels
344 #define dn_expand		__dn_expand
345 #define dn_skipname		__dn_skipname
346 #define fp_resstat		__fp_resstat
347 #define loc_aton		__loc_aton
348 #define loc_ntoa		__loc_ntoa
349 #define p_cdname		__p_cdname
350 #define p_cdnname		__p_cdnname
351 #define p_class			__p_class
352 #define p_fqname		__p_fqname
353 #define p_fqnname		__p_fqnname
354 #define p_option		__p_option
355 #define p_secstodate		__p_secstodate
356 #define p_section		__p_section
357 #define p_time			__p_time
358 #define p_type			__p_type
359 #define p_rcode			__p_rcode
360 #define p_sockun		__p_sockun
361 #define putlong			__putlong
362 #define putshort		__putshort
363 #define res_dnok		__res_dnok
364 #if 0
365 #define res_findzonecut		__res_findzonecut
366 #endif
367 #define res_findzonecut2	__res_findzonecut2
368 #define res_hnok		__res_hnok
369 #define res_hostalias		__res_hostalias
370 #define res_mailok		__res_mailok
371 #define res_nameinquery		__res_nameinquery
372 #define res_nclose		__res_nclose
373 #define res_ninit		__res_ninit
374 #define res_nmkquery		__res_nmkquery
375 #define res_pquery		__res_pquery
376 #define res_nquery		__res_nquery
377 #define res_nquerydomain	__res_nquerydomain
378 #define res_nsearch		__res_nsearch
379 #define res_nsend		__res_nsend
380 #if 0
381 #define res_nsendsigned		__res_nsendsigned
382 #endif
383 #define res_nisourserver	__res_nisourserver
384 #define res_ownok		__res_ownok
385 #define res_queriesmatch	__res_queriesmatch
386 #define res_randomid		__res_randomid
387 #define sym_ntop		__sym_ntop
388 #define sym_ntos		__sym_ntos
389 #define sym_ston		__sym_ston
390 #define res_nopt		__res_nopt
391 #define res_ndestroy		__res_ndestroy
392 #define	res_nametoclass		__res_nametoclass
393 #define	res_nametotype		__res_nametotype
394 #define	res_setservers		__res_setservers
395 #define	res_getservers		__res_getservers
396 #if 0
397 #define	res_buildprotolist	__res_buildprotolist
398 #define	res_destroyprotolist	__res_destroyprotolist
399 #define	res_destroyservicelist	__res_destroyservicelist
400 #define	res_get_nibblesuffix	__res_get_nibblesuffix
401 #define	res_get_nibblesuffix2	__res_get_nibblesuffix2
402 #endif
403 #define	res_ourserver_p		__res_ourserver_p
404 #if 0
405 #define	res_protocolname	__res_protocolname
406 #define	res_protocolnumber	__res_protocolnumber
407 #endif
408 #define	res_send_setqhook	__res_send_setqhook
409 #define	res_send_setrhook	__res_send_setrhook
410 #if 0
411 #define	res_servicename		__res_servicename
412 #define	res_servicenumber	__res_servicenumber
413 #endif
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(u_int32_t, u_char *);
428 void		putshort(u_int16_t, u_char *);
429 #ifndef __ultrix__
430 u_int16_t	_getshort(const u_char *);
431 u_int32_t	_getlong(const u_char *);
432 #endif
433 const char *	p_class(int);
434 const char *	p_time(u_int32_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 *, int, char *, int);
441 const u_char *	p_fqname(const u_char *, const u_char *, FILE *);
442 const char *	p_option(u_long);
443 char *		p_secstodate(u_long);
444 int		dn_count_labels(const char *);
445 int		dn_comp(const char *, u_char *, int, u_char **, u_char **);
446 int		dn_expand(const u_char *, const u_char *, const u_char *,
447 			  char *, int);
448 u_int		res_randomid(void);
449 int		res_nameinquery(const char *, int, int, const u_char *,
450 				const u_char *);
451 int		res_queriesmatch(const u_char *, const u_char *,
452 				 const u_char *, const u_char *);
453 const char *	p_section(int, int);
454 /* Things involving a resolver context. */
455 int		res_ninit(res_state);
456 int		res_nisourserver(const res_state, const struct sockaddr_in *);
457 void		fp_resstat(const res_state, FILE *);
458 void		res_pquery(const res_state, const u_char *, int, FILE *);
459 const char *	res_hostalias(const res_state, const char *, char *, size_t);
460 int		res_nquery(res_state, const char *, int, int, u_char *, int);
461 int		res_nsearch(res_state, const char *, int, int, u_char *, int);
462 int		res_nquerydomain(res_state, const char *, const char *,
463 				 int, int, u_char *, int);
464 int		res_nmkquery(res_state, int, const char *, int, int,
465 			     const u_char *, int, const u_char *,
466 			     u_char *, int);
467 int		res_nsend(res_state, const u_char *, int, u_char *, int);
468 #if 0
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 #endif
474 int		res_findzonecut2(res_state, const char *, ns_class, int,
475 				 char *, size_t,
476 				 union res_sockaddr_union *, int);
477 void		res_nclose(res_state);
478 int		res_nopt(res_state, int, u_char *, int, int);
479 void		res_send_setqhook(res_send_qhook);
480 void		res_send_setrhook(res_send_rhook);
481 int		__res_vinit(res_state, int);
482 #if 0
483 void		res_destroyservicelist(void);
484 const char *	res_servicename(u_int16_t, const char *);
485 const char *	res_protocolname(int);
486 void		res_destroyprotolist(void);
487 void		res_buildprotolist(void);
488 const char *	res_get_nibblesuffix(res_state);
489 const char *	res_get_nibblesuffix2(res_state);
490 #endif
491 void		res_ndestroy(res_state);
492 u_int16_t	res_nametoclass(const char *, int *);
493 u_int16_t	res_nametotype(const char *, int *);
494 void		res_setservers(res_state, const union res_sockaddr_union *,
495 			       int);
496 int		res_getservers(res_state, union res_sockaddr_union *, int);
497 __END_DECLS
498 
499 #endif /* !_RESOLV_H_ */
500