xref: /netbsd-src/include/resolv.h (revision b5677b36047b601b9addaaa494a58ceae82c2a6c)
1 /*	$NetBSD: resolv.h,v 1.35 2008/06/21 20:24:40 christos 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 1.23.564.1 2008/04/03 02:12:21 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 #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 #ifdef sun
151 	u_int	options;		/*%< option flags - see below. */
152 #else
153 	u_long	options;		/*%< option flags - see below. */
154 #endif
155 	int	nscount;		/*%< number of name servers */
156 	struct sockaddr_in
157 		nsaddr_list[MAXNS];	/*%< address of name server */
158 #define	nsaddr	nsaddr_list[0]		/*%< for backward compatibility */
159 	u_short	id;			/*%< current message id */
160 	char	*dnsrch[MAXDNSRCH+1];	/*%< components of domain to search */
161 	char	defdname[256];		/*%< default domain (deprecated) */
162 #ifdef sun
163 	u_int	pfcode;			/*%< RES_PRF_ flags - see below. */
164 #else
165 	u_long	pfcode;			/*%< RES_PRF_ flags - see below. */
166 #endif
167 	unsigned ndots:4;		/*%< threshold for initial abs. query */
168 	unsigned nsort:4;		/*%< number of elements in sort_list[] */
169 	char	unused[3];
170 	struct {
171 		struct in_addr	addr;
172 		uint32_t	mask;
173 	} sort_list[MAXRESOLVSORT];
174 #ifdef __OLD_RES_STATE
175 	char lookups[4];
176 #else
177 	res_send_qhook qhook;		/*%< query hook */
178 	res_send_rhook rhook;		/*%< response hook */
179 	int	res_h_errno;		/*%< last one set for this context */
180 	int	_vcsock;		/*%< PRIVATE: for res_send VC i/o */
181 	u_int	_flags;			/*%< PRIVATE: see below */
182 	u_int	_pad;			/*%< make _u 64 bit aligned */
183 	union {
184 		/* On an 32-bit arch this means 512b total. */
185 		char	pad[72 - 4*sizeof (int) - 2*sizeof (void *)];
186 		struct {
187 			uint16_t		nscount;
188 			uint16_t		nstimes[MAXNS];	/*%< ms. */
189 			int			nssocks[MAXNS];
190 			struct __res_state_ext *ext;	/*%< extention for IPv6 */
191 		} _ext;
192 	} _u;
193 #endif
194 };
195 
196 typedef struct __res_state *res_state;
197 
198 union res_sockaddr_union {
199 	struct sockaddr_in	sin;
200 #ifdef IN6ADDR_ANY_INIT
201 	struct sockaddr_in6	sin6;
202 #endif
203 #ifdef ISC_ALIGN64
204 	int64_t			__align64;	/*%< 64bit alignment */
205 #else
206 	int32_t			__align32;	/*%< 32bit alignment */
207 #endif
208 	char			__space[128];   /* max size */
209 };
210 
211 /*%
212  * Resolver flags (used to be discrete per-module statics ints).
213  */
214 #define	RES_F_VC	0x00000001	/*%< socket is TCP */
215 #define	RES_F_CONN	0x00000002	/*%< socket is connected */
216 #define	RES_F_EDNS0ERR	0x00000004	/*%< EDNS0 caused errors */
217 #define	RES_F__UNUSED	0x00000008	/*%< (unused) */
218 #define	RES_F_LASTMASK	0x000000F0	/*%< ordinal server of last res_nsend */
219 #define	RES_F_LASTSHIFT	4		/*%< bit position of LASTMASK "flag" */
220 #define	RES_GETLAST(res) (((res)._flags & RES_F_LASTMASK) >> RES_F_LASTSHIFT)
221 
222 /* res_findzonecut2() options */
223 #define	RES_EXHAUSTIVE	0x00000001	/*%< always do all queries */
224 #define	RES_IPV4ONLY	0x00000002	/*%< IPv4 only */
225 #define	RES_IPV6ONLY	0x00000004	/*%< IPv6 only */
226 
227 /*%
228  * Resolver options (keep these in synch with res_debug.c, please)
229  */
230 #define RES_INIT	0x00000001	/*%< address initialized */
231 #define RES_DEBUG	0x00000002	/*%< print debug messages */
232 #define RES_AAONLY	0x00000004	/*%< authoritative answers only (!IMPL)*/
233 #define RES_USEVC	0x00000008	/*%< use virtual circuit */
234 #define RES_PRIMARY	0x00000010	/*%< query primary server only (!IMPL) */
235 #define RES_IGNTC	0x00000020	/*%< ignore trucation errors */
236 #define RES_RECURSE	0x00000040	/*%< recursion desired */
237 #define RES_DEFNAMES	0x00000080	/*%< use default domain name */
238 #define RES_STAYOPEN	0x00000100	/*%< Keep TCP socket open */
239 #define RES_DNSRCH	0x00000200	/*%< search up local domain tree */
240 #define	RES_INSECURE1	0x00000400	/*%< type 1 security disabled */
241 #define	RES_INSECURE2	0x00000800	/*%< type 2 security disabled */
242 #define	RES_NOALIASES	0x00001000	/*%< shuts off HOSTALIASES feature */
243 #define	RES_USE_INET6	0x00002000	/*%< use/map IPv6 in gethostbyname() */
244 #define RES_ROTATE	0x00004000	/*%< rotate ns list after each query */
245 #define	RES_NOCHECKNAME	0x00008000	/*%< do not check names for sanity. */
246 #define	RES_KEEPTSIG	0x00010000	/*%< do not strip TSIG records */
247 #define	RES_BLAST	0x00020000	/*%< blast all recursive servers */
248 #define RES_NSID	0x00040000      /*%< request name server ID */
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_isourserver		__res_isourserver
302 #define	res_opt			__res_opt
303 #define	res_querydomain		__res_querydomain
304 #define res_send		__res_send
305 #define res_sendsigned		__res_sendsigned
306 
307 #ifdef notdef
308 /* NetBSD protects these via weak symbols. */
309 #define	res_init		__res_init
310 #define	res_query		__res_query
311 #define	res_mkquery		__res_mkquery
312 #define	dn_expand		__dn_expand
313 #define	res_search		__res_search
314 #endif
315 
316 __BEGIN_DECLS
317 void		fp_nquery(const u_char *, int, FILE *);
318 void		fp_query(const u_char *, FILE *);
319 const char *	hostalias(const char *);
320 void		p_query(const u_char *);
321 void		res_close(void);
322 int		res_init(void);
323 int		res_opt(int, u_char *, int, int);
324 int		res_isourserver(const struct sockaddr_in *);
325 int		res_mkquery(int, const char *, int, int, const u_char *,
326 				 int, const u_char *, u_char *, int);
327 int		res_query(const char *, int, int, u_char *, int);
328 int		res_querydomain(const char *, const char *, int, int,
329 				     u_char *, int);
330 int		res_search(const char *, int, int, u_char *, int);
331 int		res_send(const u_char *, int, u_char *, int);
332 int		res_sendsigned(const u_char *, int, ns_tsig_key *,
333 				    u_char *, int);
334 __END_DECLS
335 #endif
336 
337 #if !defined(SHARED_LIBBIND) || defined(LIB)
338 /*
339  * If libbind is a shared object (well, DLL anyway)
340  * these externs break the linker when resolv.h is
341  * included by a lib client (like named)
342  * Make them go away if a client is including this
343  *
344  */
345 extern const struct res_sym __p_key_syms[];
346 extern const struct res_sym __p_cert_syms[];
347 extern const struct res_sym __p_class_syms[];
348 extern const struct res_sym __p_type_syms[];
349 extern const struct res_sym __p_rcode_syms[];
350 #endif /* SHARED_LIBBIND */
351 
352 #define b64_ntop		__b64_ntop
353 #define b64_pton		__b64_pton
354 #define dn_comp			__dn_comp
355 #define dn_count_labels		__dn_count_labels
356 #define dn_skipname		__dn_skipname
357 #define fp_resstat		__fp_resstat
358 #define loc_aton		__loc_aton
359 #define loc_ntoa		__loc_ntoa
360 #define p_cdname		__p_cdname
361 #define p_cdnname		__p_cdnname
362 #define p_class			__p_class
363 #define p_fqname		__p_fqname
364 #define p_fqnname		__p_fqnname
365 #define p_option		__p_option
366 #define p_secstodate		__p_secstodate
367 #define p_section		__p_section
368 #define p_time			__p_time
369 #define p_type			__p_type
370 #define p_rcode			__p_rcode
371 #define p_sockun		__p_sockun
372 #define putlong			__putlong
373 #define putshort		__putshort
374 #define res_dnok		__res_dnok
375 #define res_findzonecut		__res_findzonecut
376 #define res_findzonecut2	__res_findzonecut2
377 #define res_hnok		__res_hnok
378 #define res_hostalias		__res_hostalias
379 #define res_mailok		__res_mailok
380 #define res_nameinquery		__res_nameinquery
381 #define res_nclose		__res_nclose
382 #define res_ninit		__res_ninit
383 #define res_nmkquery		__res_nmkquery
384 #define res_pquery		__res_pquery
385 #define res_nquery		__res_nquery
386 #define res_nquerydomain	__res_nquerydomain
387 #define res_nsearch		__res_nsearch
388 #define res_nsend		__res_nsend
389 #define res_nsendsigned		__res_nsendsigned
390 #define res_nisourserver	__res_nisourserver
391 #define res_ownok		__res_ownok
392 #define res_queriesmatch	__res_queriesmatch
393 #define res_randomid		__res_randomid
394 #define sym_ntop		__sym_ntop
395 #define sym_ntos		__sym_ntos
396 #define sym_ston		__sym_ston
397 #define res_nopt		__res_nopt
398 #define res_nopt_rdata       	__res_nopt_rdata
399 #define res_ndestroy		__res_ndestroy
400 #define	res_nametoclass		__res_nametoclass
401 #define	res_nametotype		__res_nametotype
402 #define	res_setservers		__res_setservers
403 #define	res_getservers		__res_getservers
404 #define	res_buildprotolist	__res_buildprotolist
405 #define	res_destroyprotolist	__res_destroyprotolist
406 #define	res_destroyservicelist	__res_destroyservicelist
407 #define	res_get_nibblesuffix	__res_get_nibblesuffix
408 #define	res_get_nibblesuffix2	__res_get_nibblesuffix2
409 #define	res_ourserver_p		__res_ourserver_p
410 #define	res_protocolname	__res_protocolname
411 #define	res_protocolnumber	__res_protocolnumber
412 #define	res_send_setqhook	__res_send_setqhook
413 #define	res_send_setrhook	__res_send_setrhook
414 #define	res_servicename		__res_servicename
415 #define	res_servicenumber	__res_servicenumber
416 __BEGIN_DECLS
417 int		res_hnok(const char *);
418 int		res_ownok(const char *);
419 int		res_mailok(const char *);
420 int		res_dnok(const char *);
421 int		sym_ston(const struct res_sym *, const char *, int *);
422 const char *	sym_ntos(const struct res_sym *, int, int *);
423 const char *	sym_ntop(const struct res_sym *, int, int *);
424 int		b64_ntop(u_char const *, size_t, char *, size_t);
425 int		b64_pton(char const *, u_char *, size_t);
426 int		loc_aton(const char *, u_char *);
427 const char *	loc_ntoa(const u_char *, char *);
428 int		dn_skipname(const u_char *, const u_char *);
429 void		putlong(uint32_t, u_char *);
430 void		putshort(uint16_t, u_char *);
431 #ifndef __ultrix__
432 uint16_t	_getshort(const u_char *);
433 uint32_t	_getlong(const u_char *);
434 #endif
435 const char *	p_class(int);
436 const char *	p_time(uint32_t);
437 const char *	p_type(int);
438 const char *	p_rcode(int);
439 const char *	p_sockun(union res_sockaddr_union, char *, size_t);
440 const u_char *	p_cdnname(const u_char *, const u_char *, int, FILE *);
441 const u_char *	p_cdname(const u_char *, const u_char *, FILE *);
442 const u_char *	p_fqnname(const u_char *, const u_char *,
443 			       int, char *, int);
444 const u_char *	p_fqname(const u_char *, const u_char *, FILE *);
445 const char *	p_option(u_long);
446 char *		p_secstodate(u_long);
447 int		dn_count_labels(const char *);
448 int		dn_comp(const char *, u_char *, int, u_char **, u_char **);
449 int		dn_expand(const u_char *, const u_char *, const u_char *,
450 			       char *, int);
451 u_int		res_randomid(void);
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 int		res_nsendsigned(res_state, const u_char *, int,
472 				     ns_tsig_key *, u_char *, int);
473 int		res_findzonecut(res_state, const char *, ns_class, int,
474 				     char *, size_t, struct in_addr *, int);
475 int		res_findzonecut2(res_state, const char *, ns_class, int,
476 				      char *, size_t,
477 				      union res_sockaddr_union *, int);
478 void		res_nclose(res_state);
479 int		res_nopt(res_state, int, u_char *, int, int);
480 int		res_nopt_rdata(res_state, int, u_char *, int, u_char *,
481 				    u_short, u_short, u_char *);
482 void		res_send_setqhook(res_send_qhook);
483 void		res_send_setrhook(res_send_rhook);
484 int		__res_vinit(res_state, int);
485 void		res_destroyservicelist(void);
486 const char *	res_servicename(uint16_t, const char *);
487 const char *	res_protocolname(int);
488 void		res_destroyprotolist(void);
489 void		res_buildprotolist(void);
490 const char *	res_get_nibblesuffix(res_state);
491 const char *	res_get_nibblesuffix2(res_state);
492 void		res_ndestroy(res_state);
493 uint16_t	res_nametoclass(const char *, int *);
494 uint16_t	res_nametotype(const char *, int *);
495 void		res_setservers(res_state,
496 				    const union res_sockaddr_union *, int);
497 int		res_getservers(res_state,
498 				    union res_sockaddr_union *, int);
499 __END_DECLS
500 
501 #endif /* !_RESOLV_H_ */
502