xref: /freebsd/include/resolv.h (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: (ISC AND BSD-3-Clause)
3  *
4  * Portions Copyright (C) 2004, 2005, 2008, 2009  Internet Systems Consortium, Inc. ("ISC")
5  * Portions Copyright (C) 1995-2003  Internet Software Consortium.
6  *
7  * Permission to use, copy, modify, and/or distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
12  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
13  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
14  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
15  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
16  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
17  * PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 /*
21  * Copyright (c) 1983, 1987, 1989
22  *    The Regents of the University of California.  All rights reserved.
23  *
24  * Redistribution and use in source and binary forms, with or without
25  * modification, are permitted provided that the following conditions
26  * are met:
27  * 1. Redistributions of source code must retain the above copyright
28  *    notice, this list of conditions and the following disclaimer.
29  * 2. Redistributions in binary form must reproduce the above copyright
30  *    notice, this list of conditions and the following disclaimer in the
31  *    documentation and/or other materials provided with the distribution.
32  * 3. Neither the name of the University nor the names of its contributors
33  *    may be used to endorse or promote products derived from this software
34  *    without specific prior written permission.
35  *
36  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
37  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
40  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
44  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
45  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46  * SUCH DAMAGE.
47  */
48 
49 /*%
50  *	@(#)resolv.h	8.1 (Berkeley) 6/2/93
51  *	$Id: resolv.h,v 1.30 2009/03/03 01:52:48 each Exp $
52  * $FreeBSD$
53  */
54 
55 #ifndef _RESOLV_H_
56 #define	_RESOLV_H_
57 
58 #include <sys/param.h>
59 #include <sys/types.h>
60 #include <sys/cdefs.h>
61 #include <sys/socket.h>
62 #include <stdio.h>
63 #include <arpa/nameser.h>
64 
65 /*%
66  * Revision information.  This is the release date in YYYYMMDD format.
67  * It can change every day so the right thing to do with it is use it
68  * in preprocessor commands such as "#if (__RES > 19931104)".  Do not
69  * compare for equality; rather, use it to determine whether your resolver
70  * is new enough to contain a certain feature.
71  */
72 
73 #define	__RES	20090302
74 
75 /*%
76  * This used to be defined in res_query.c, now it's in herror.c.
77  * [XXX no it's not.  It's in irs/irs_data.c]
78  * It was
79  * never extern'd by any *.h file before it was placed here.  For thread
80  * aware programs, the last h_errno value set is stored in res->h_errno.
81  *
82  * XXX:	There doesn't seem to be a good reason for exposing RES_SET_H_ERRNO
83  *	(and __h_errno_set) to the public via <resolv.h>.
84  * XXX:	__h_errno_set is really part of IRS, not part of the resolver.
85  *	If somebody wants to build and use a resolver that doesn't use IRS,
86  *	what do they do?  Perhaps something like
87  *		#ifdef WANT_IRS
88  *		# define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
89  *		#else
90  *		# define RES_SET_H_ERRNO(r,x) (h_errno = (r)->res_h_errno = (x))
91  *		#endif
92  */
93 
94 #define RES_SET_H_ERRNO(r,x) __h_errno_set(r,x)
95 struct __res_state; /*%< forward */
96 __BEGIN_DECLS
97 void __h_errno_set(struct __res_state *, int);
98 __END_DECLS
99 
100 /*%
101  * Resolver configuration file.
102  * Normally not present, but may contain the address of the
103  * initial name server(s) to query and the domain search list.
104  */
105 
106 #ifndef _PATH_RESCONF
107 #define	_PATH_RESCONF        "/etc/resolv.conf"
108 #endif
109 
110 typedef enum { res_goahead, res_nextns, res_modified, res_done, res_error }
111 	res_sendhookact;
112 
113 typedef res_sendhookact (*res_send_qhook)(struct sockaddr * const *,
114 					  const u_char **, int *,
115 					  u_char *, int, int *);
116 
117 typedef res_sendhookact (*res_send_rhook)(const struct sockaddr *,
118 					  const u_char *, int, u_char *,
119 					  int, int *);
120 
121 struct res_sym {
122 	int		number;	   /*%< Identifying number, like T_MX */
123 	const char *	name;	   /*%< Its symbolic name, like "MX" */
124 	const char *	humanname; /*%< Its fun name, like "mail exchanger" */
125 };
126 
127 /*%
128  * Global defines and variables for resolver stub.
129  */
130 #define	MAXNS			3	/*%< max # name servers we'll track */
131 #define	MAXDFLSRCH		3	/*%< # default domain levels to try */
132 #define	MAXDNSRCH		6	/*%< max # domains in search path */
133 #define	LOCALDOMAINPARTS	2	/*%< min levels in name that is "local" */
134 #define	RES_TIMEOUT		5	/*%< min. seconds between retries */
135 #define	MAXRESOLVSORT		10	/*%< number of net to sort on */
136 #define	RES_MAXNDOTS		15	/*%< should reflect bit field size */
137 #define	RES_MAXRETRANS		30	/*%< only for resolv.conf/RES_OPTIONS */
138 #define	RES_MAXRETRY		5	/*%< only for resolv.conf/RES_OPTIONS */
139 #define	RES_DFLRETRY		2	/*%< Default #/tries. */
140 #define	RES_MAXTIME		65535	/*%< Infinity, in milliseconds. */
141 struct __res_state_ext;
142 
143 struct __res_state {
144 	int	retrans;	 	/*%< retransmission time interval */
145 	int	retry;			/*%< number of times to retransmit */
146 	/*
147 	 * XXX: If `sun' is defined, `options' and `pfcode' are
148 	 * defined as u_int in original BIND9 distribution.  However,
149 	 * it breaks binary backward compatibility against FreeBSD's
150 	 * resolver.  So, we changed not to see `sun'.
151 	 */
152 #if defined(sun) && 0
153 	u_int	options;		/*%< option flags - see below. */
154 #else
155 	u_long	options;		/*%< option flags - see below. */
156 #endif
157 	int	nscount;		/*%< number of name servers */
158 	struct sockaddr_in
159 		nsaddr_list[MAXNS];	/*%< address of name server */
160 #define	nsaddr	nsaddr_list[0]		/*%< for backward compatibility */
161 	u_short	id;			/*%< current message id */
162 	char	*dnsrch[MAXDNSRCH+1];	/*%< components of domain to search */
163 	char	defdname[256];		/*%< default domain (deprecated) */
164 #if defined(sun) && 0
165 	u_int	pfcode;			/*%< RES_PRF_ flags - see below. */
166 #else
167 	u_long	pfcode;			/*%< RES_PRF_ flags - see below. */
168 #endif
169 	unsigned ndots:4;		/*%< threshold for initial abs. query */
170 	unsigned nsort:4;		/*%< number of elements in sort_list[] */
171 	char	unused[3];
172 	struct {
173 		struct in_addr	addr;
174 		u_int32_t	mask;
175 	} sort_list[MAXRESOLVSORT];
176 	res_send_qhook qhook;		/*%< query hook */
177 	res_send_rhook rhook;		/*%< response hook */
178 	int	res_h_errno;		/*%< last one set for this context */
179 	int	_vcsock;		/*%< PRIVATE: for res_send VC i/o */
180 	u_int	_flags;			/*%< PRIVATE: see below */
181 	u_int	_pad;			/*%< make _u 64 bit aligned */
182 	union {
183 		/* On an 32-bit arch this means 512b total. */
184 		char	pad[72 - 4*sizeof (int) - 3*sizeof (void *)];
185 		struct {
186 			u_int16_t		nscount;
187 			u_int16_t		nstimes[MAXNS];	/*%< ms. */
188 			int			nssocks[MAXNS];
189 			struct __res_state_ext *ext;	/*%< extension for IPv6 */
190 		} _ext;
191 	} _u;
192 	u_char	*_rnd;			/*%< PRIVATE: random state */
193 };
194 
195 typedef struct __res_state *res_state;
196 
197 union res_sockaddr_union {
198 	struct sockaddr_in	sin;
199 #ifdef IN6ADDR_ANY_INIT
200 	struct sockaddr_in6	sin6;
201 #endif
202 #ifdef ISC_ALIGN64
203 	int64_t			__align64;	/*%< 64bit alignment */
204 #else
205 	int32_t			__align32;	/*%< 32bit alignment */
206 #endif
207 	char			__space[128];   /*%< max size */
208 };
209 
210 /*%
211  * Resolver flags (used to be discrete per-module statics ints).
212  */
213 #define	RES_F_VC	0x00000001	/*%< socket is TCP */
214 #define	RES_F_CONN	0x00000002	/*%< socket is connected */
215 #define	RES_F_EDNS0ERR	0x00000004	/*%< EDNS0 caused errors */
216 #define	RES_F__UNUSED	0x00000008	/*%< (unused) */
217 #define	RES_F_LASTMASK	0x000000F0	/*%< ordinal server of last res_nsend */
218 #define	RES_F_LASTSHIFT	4		/*%< bit position of LASTMASK "flag" */
219 #define	RES_GETLAST(res) (((res)._flags & RES_F_LASTMASK) >> RES_F_LASTSHIFT)
220 
221 /* res_findzonecut2() options */
222 #define	RES_EXHAUSTIVE	0x00000001	/*%< always do all queries */
223 #define	RES_IPV4ONLY	0x00000002	/*%< IPv4 only */
224 #define	RES_IPV6ONLY	0x00000004	/*%< IPv6 only */
225 
226 /*%
227  * Resolver options (keep these in synch with res_debug.c, please)
228  */
229 #define RES_INIT	0x00000001	/*%< address initialized */
230 #define RES_DEBUG	0x00000002	/*%< print debug messages */
231 #define RES_AAONLY	0x00000004	/*%< authoritative answers only (!IMPL)*/
232 #define RES_USEVC	0x00000008	/*%< use virtual circuit */
233 #define RES_PRIMARY	0x00000010	/*%< query primary server only (!IMPL) */
234 #define RES_IGNTC	0x00000020	/*%< ignore truncation errors */
235 #define RES_RECURSE	0x00000040	/*%< recursion desired */
236 #define RES_DEFNAMES	0x00000080	/*%< use default domain name */
237 #define RES_STAYOPEN	0x00000100	/*%< Keep TCP socket open */
238 #define RES_DNSRCH	0x00000200	/*%< search up local domain tree */
239 #define	RES_INSECURE1	0x00000400	/*%< type 1 security disabled */
240 #define	RES_INSECURE2	0x00000800	/*%< type 2 security disabled */
241 #define	RES_NOALIASES	0x00001000	/*%< shuts off HOSTALIASES feature */
242 #define	RES_USE_INET6	0x00002000	/*%< use/map IPv6 in gethostbyname() */
243 #define RES_ROTATE	0x00004000	/*%< rotate ns list after each query */
244 #define	RES_NOCHECKNAME	0x00008000	/*%< do not check names for sanity. */
245 #define	RES_KEEPTSIG	0x00010000	/*%< do not strip TSIG records */
246 #define	RES_BLAST	0x00020000	/*%< blast all recursive servers */
247 #define RES_NSID	0x00040000      /*%< request name server ID */
248 #define RES_NOTLDQUERY	0x00100000	/*%< don't unqualified name as a tld */
249 #define RES_USE_DNSSEC	0x00200000	/*%< use DNSSEC using OK bit in OPT */
250 /* #define RES_DEBUG2	0x00400000 */	/* nslookup internal */
251 /* KAME extensions: use higher bit to avoid conflict with ISC use */
252 #define RES_USE_DNAME	0x10000000	/*%< use DNAME */
253 #define RES_USE_EDNS0	0x40000000	/*%< use EDNS0 if configured */
254 #define RES_NO_NIBBLE2	0x80000000	/*%< disable alternate nibble lookup */
255 
256 #define RES_DEFAULT	(RES_RECURSE | RES_DEFNAMES | \
257 			 RES_DNSRCH | RES_NO_NIBBLE2)
258 
259 /*%
260  * Resolver "pfcode" values.  Used by dig.
261  */
262 #define	RES_PRF_STATS	0x00000001
263 #define	RES_PRF_UPDATE	0x00000002
264 #define	RES_PRF_CLASS   0x00000004
265 #define	RES_PRF_CMD	0x00000008
266 #define	RES_PRF_QUES	0x00000010
267 #define	RES_PRF_ANS	0x00000020
268 #define	RES_PRF_AUTH	0x00000040
269 #define	RES_PRF_ADD	0x00000080
270 #define	RES_PRF_HEAD1	0x00000100
271 #define	RES_PRF_HEAD2	0x00000200
272 #define	RES_PRF_TTLID	0x00000400
273 #define	RES_PRF_HEADX	0x00000800
274 #define	RES_PRF_QUERY	0x00001000
275 #define	RES_PRF_REPLY	0x00002000
276 #define	RES_PRF_INIT	0x00004000
277 #define	RES_PRF_TRUNC	0x00008000
278 /*			0x00010000	*/
279 
280 /* Things involving an internal (static) resolver context. */
281 __BEGIN_DECLS
282 extern struct __res_state *__res_state(void);
283 __END_DECLS
284 #define _res (*__res_state())
285 
286 #ifndef __BIND_NOSTATIC
287 #define fp_nquery		__fp_nquery
288 #define fp_query		__fp_query
289 #define hostalias		__hostalias
290 #define p_query			__p_query
291 #define res_close		__res_close
292 #define res_init		__res_init
293 #define res_isourserver		__res_isourserver
294 #define res_mkquery		__res_mkquery
295 #define res_opt			__res_opt
296 #define res_query		__res_query
297 #define res_querydomain		__res_querydomain
298 #define res_search		__res_search
299 #define res_send		__res_send
300 #define res_sendsigned		__res_sendsigned
301 
302 __BEGIN_DECLS
303 void		fp_nquery(const u_char *, int, FILE *);
304 void		fp_query(const u_char *, FILE *);
305 const char *	hostalias(const char *);
306 void		p_query(const u_char *);
307 void		res_close(void);
308 int		res_init(void);
309 int		res_isourserver(const struct sockaddr_in *);
310 int		res_mkquery(int, const char *, int, int, const u_char *,
311 				 int, const u_char *, u_char *, int);
312 int		res_opt(int, u_char *, int, int);
313 int		res_query(const char *, int, int, u_char *, int);
314 int		res_querydomain(const char *, const char *, int, int,
315 				     u_char *, int);
316 int		res_search(const char *, int, int, u_char *, int);
317 int		res_send(const u_char *, int, u_char *, int);
318 int		res_sendsigned(const u_char *, int, ns_tsig_key *,
319 				    u_char *, int);
320 __END_DECLS
321 #endif
322 
323 #if !defined(SHARED_LIBBIND) || defined(LIB)
324 /*
325  * If libbind is a shared object (well, DLL anyway)
326  * these externs break the linker when resolv.h is
327  * included by a lib client (like named)
328  * Make them go away if a client is including this
329  *
330  */
331 extern const struct res_sym __p_key_syms[];
332 extern const struct res_sym __p_cert_syms[];
333 extern const struct res_sym __p_class_syms[];
334 extern const struct res_sym __p_type_syms[];
335 extern const struct res_sym __p_rcode_syms[];
336 #endif /* SHARED_LIBBIND */
337 
338 #define b64_ntop		__b64_ntop
339 #define b64_pton		__b64_pton
340 #define dn_comp			__dn_comp
341 #define dn_count_labels		__dn_count_labels
342 #define dn_expand		__dn_expand
343 #define dn_skipname		__dn_skipname
344 #define fp_resstat		__fp_resstat
345 #define loc_aton		__loc_aton
346 #define loc_ntoa		__loc_ntoa
347 #define p_cdname		__p_cdname
348 #define p_cdnname		__p_cdnname
349 #define p_class			__p_class
350 #define p_fqname		__p_fqname
351 #define p_fqnname		__p_fqnname
352 #define p_option		__p_option
353 #define p_secstodate		__p_secstodate
354 #define p_section		__p_section
355 #define p_time			__p_time
356 #define p_type			__p_type
357 #define p_rcode			__p_rcode
358 #define p_sockun		__p_sockun
359 #define putlong			__putlong
360 #define putshort		__putshort
361 #define res_dnok		__res_dnok
362 #if 0
363 #define res_findzonecut		__res_findzonecut
364 #endif
365 #define res_findzonecut2	__res_findzonecut2
366 #define res_hnok		__res_hnok
367 #define res_hostalias		__res_hostalias
368 #define res_mailok		__res_mailok
369 #define res_nameinquery		__res_nameinquery
370 #define res_nclose		__res_nclose
371 #define res_ninit		__res_ninit
372 #define res_nmkquery		__res_nmkquery
373 #define res_pquery		__res_pquery
374 #define res_nquery		__res_nquery
375 #define res_nquerydomain	__res_nquerydomain
376 #define res_nsearch		__res_nsearch
377 #define res_nsend		__res_nsend
378 #if 0
379 #define res_nsendsigned		__res_nsendsigned
380 #endif
381 #define res_nisourserver	__res_nisourserver
382 #define res_ownok		__res_ownok
383 #define res_queriesmatch	__res_queriesmatch
384 #define res_rndinit		__res_rndinit
385 #define res_randomid		__res_randomid
386 #define res_nrandomid		__res_nrandomid
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_nopt_rdata       	__res_nopt_rdata
392 #define res_ndestroy		__res_ndestroy
393 #define	res_nametoclass		__res_nametoclass
394 #define	res_nametotype		__res_nametotype
395 #define	res_setservers		__res_setservers
396 #define	res_getservers		__res_getservers
397 #if 0
398 #define	res_buildprotolist	__res_buildprotolist
399 #define	res_destroyprotolist	__res_destroyprotolist
400 #define	res_destroyservicelist	__res_destroyservicelist
401 #define	res_get_nibblesuffix	__res_get_nibblesuffix
402 #define	res_get_nibblesuffix2	__res_get_nibblesuffix2
403 #endif
404 #define	res_ourserver_p		__res_ourserver_p
405 #if 0
406 #define	res_protocolname	__res_protocolname
407 #define	res_protocolnumber	__res_protocolnumber
408 #endif
409 #define	res_send_setqhook	__res_send_setqhook
410 #define	res_send_setrhook	__res_send_setrhook
411 #if 0
412 #define	res_servicename		__res_servicename
413 #define	res_servicenumber	__res_servicenumber
414 #endif
415 __BEGIN_DECLS
416 int		res_hnok(const char *);
417 int		res_ownok(const char *);
418 int		res_mailok(const char *);
419 int		res_dnok(const char *);
420 int		sym_ston(const struct res_sym *, const char *, int *);
421 const char *	sym_ntos(const struct res_sym *, int, int *);
422 const char *	sym_ntop(const struct res_sym *, int, int *);
423 int		b64_ntop(u_char const *, size_t, char *, size_t);
424 int		b64_pton(char const *, u_char *, size_t);
425 int		loc_aton(const char *, u_char *);
426 const char *	loc_ntoa(const u_char *, char *);
427 int		dn_skipname(const u_char *, const u_char *);
428 void		putlong(u_int32_t, u_char *);
429 void		putshort(u_int16_t, u_char *);
430 #ifndef __ultrix__
431 u_int16_t	_getshort(const u_char *);
432 u_int32_t	_getlong(const u_char *);
433 #endif
434 const char *	p_class(int);
435 const char *	p_time(u_int32_t);
436 const char *	p_type(int);
437 const char *	p_rcode(int);
438 const char *	p_sockun(union res_sockaddr_union, char *, size_t);
439 const u_char *	p_cdnname(const u_char *, const u_char *, int, FILE *);
440 const u_char *	p_cdname(const u_char *, const u_char *, FILE *);
441 const u_char *	p_fqnname(const u_char *, const u_char *, 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 void		res_rndinit(res_state);
450 u_int		res_randomid(void);
451 u_int		res_nrandomid(res_state);
452 int		res_nameinquery(const char *, int, int, const u_char *,
453 				const u_char *);
454 int		res_queriesmatch(const u_char *, const u_char *,
455 				 const u_char *, const u_char *);
456 const char *	p_section(int, int);
457 /* Things involving a resolver context. */
458 int		res_ninit(res_state);
459 int		res_nisourserver(const res_state, const struct sockaddr_in *);
460 void		fp_resstat(const res_state, FILE *);
461 void		res_pquery(const res_state, const u_char *, int, FILE *);
462 const char *	res_hostalias(const res_state, const char *, char *, size_t);
463 int		res_nquery(res_state, const char *, int, int, u_char *, int);
464 int		res_nsearch(res_state, const char *, int, int, u_char *, int);
465 int		res_nquerydomain(res_state, const char *, const char *,
466 				 int, int, u_char *, int);
467 int		res_nmkquery(res_state, int, const char *, int, int,
468 			     const u_char *, int, const u_char *,
469 			     u_char *, int);
470 int		res_nsend(res_state, const u_char *, int, u_char *, int);
471 #if 0
472 int		res_nsendsigned(res_state, const u_char *, int,
473 				ns_tsig_key *, u_char *, int);
474 int		res_findzonecut(res_state, const char *, ns_class, int,
475 				char *, size_t, struct in_addr *, int);
476 #endif
477 int		res_findzonecut2(res_state, const char *, ns_class, int,
478 				 char *, size_t,
479 				 union res_sockaddr_union *, int);
480 void		res_nclose(res_state);
481 int		res_nopt(res_state, int, u_char *, int, int);
482 int		res_nopt_rdata(res_state, int, u_char *, int, u_char *,
483 			       u_short, u_short, u_char *);
484 void		res_send_setqhook(res_send_qhook);
485 void		res_send_setrhook(res_send_rhook);
486 int		__res_vinit(res_state, int);
487 #if 0
488 void		res_destroyservicelist(void);
489 const char *	res_servicename(u_int16_t, const char *);
490 const char *	res_protocolname(int);
491 void		res_destroyprotolist(void);
492 void		res_buildprotolist(void);
493 const char *	res_get_nibblesuffix(res_state);
494 const char *	res_get_nibblesuffix2(res_state);
495 #endif
496 void		res_ndestroy(res_state);
497 u_int16_t	res_nametoclass(const char *, int *);
498 u_int16_t	res_nametotype(const char *, int *);
499 void		res_setservers(res_state, const union res_sockaddr_union *,
500 			       int);
501 int		res_getservers(res_state, union res_sockaddr_union *, int);
502 __END_DECLS
503 
504 #endif /* !_RESOLV_H_ */
505 /*! \file */
506