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  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
32  *
33  * Permission to use, copy, modify, and distribute this software for any
34  * purpose with or without fee is hereby granted, provided that the above
35  * copyright notice and this permission notice appear in all copies.
36  *
37  * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
38  * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
39  * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
40  * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
41  * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
42  * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
43  * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
44  * SOFTWARE.
45  */
46 
47 /*
48  *	@(#)resolv.h	8.1 (Berkeley) 6/2/93
49  *	$BINDId: resolv.h,v 8.31 2000/03/30 20:16:50 vixie Exp $
50  */
51 
52 #ifndef _RESOLV_H_
53 
54 /* These headers are needed for types used in the `struct res_state'
55    declaration.  */
56 #include <sys/types.h>
57 #include <netinet/in.h>
58 
59 #ifndef __need_res_state
60 # define _RESOLV_H_
61 
62 # include <sys/param.h>
63 # include <sys/cdefs.h>
64 # include <stdio.h>
65 # include <arpa/nameser.h>
66 #endif
67 
68 #ifndef __res_state_defined
69 # define __res_state_defined
70 
71 typedef enum { res_goahead, res_nextns, res_modified, res_done, res_error }
72 	res_sendhookact;
73 
74 typedef res_sendhookact (*res_send_qhook) (struct sockaddr_in * const *ns,
75 					   const u_char **query,
76 					   int *querylen,
77 					   u_char *ans,
78 					   int anssiz,
79 					   int *resplen);
80 
81 typedef res_sendhookact (*res_send_rhook) (const struct sockaddr_in *ns,
82 					   const u_char *query,
83 					   int querylen,
84 					   u_char *ans,
85 					   int anssiz,
86 					   int *resplen);
87 
88 /*
89  * Global defines and variables for resolver stub.
90  */
91 # define MAXNS			3	/* max # name servers we'll track */
92 # define MAXDFLSRCH		3	/* # default domain levels to try */
93 # define MAXDNSRCH		6	/* max # domains in search path */
94 # define LOCALDOMAINPARTS	2	/* min levels in name that is "local" */
95 
96 # define RES_TIMEOUT		5	/* min. seconds between retries */
97 # define MAXRESOLVSORT		10	/* number of net to sort on */
98 # define RES_MAXNDOTS		15	/* should reflect bit field size */
99 # define RES_MAXRETRANS		30	/* only for resolv.conf/RES_OPTIONS */
100 # define RES_MAXRETRY		5	/* only for resolv.conf/RES_OPTIONS */
101 # define RES_DFLRETRY		3	/* Default #/tries. */
102 /* (glibc uses RES_DFLRETRY of 2 but also does _res.retry = 4 sometimes (!) */
103 # define RES_MAXTIME		65535	/* Infinity, in milliseconds. */
104 
105 /* _res (an instance of this structure) uses 0.5kb in bss
106  * in "ordinary" libc's (glibc, xBSD). We want to be less wasteful.
107  * We (1) shuffle and shrink some integer fields,
108  * and (2) can switch off stuff we don't support.
109  * Everything inside __UCLIBC_HAS_COMPAT_RES_STATE__
110  * is not actually used by uclibc and can be configured off.
111  * However, this will prevent some programs from building.
112  * Really obscure stuff with no observed users in the wild is under
113  * __UCLIBC_HAS_EXTRA_COMPAT_RES_STATE__.
114  * I guess it's safe to set that to N.
115  */
116 struct __res_state {
117 	/*int retrans, retry; - moved, was here */
118 	u_int32_t options;		/* (was: ulong) option flags - see below. */
119 	struct sockaddr_in nsaddr_list[MAXNS]; /* address of name server */
120 #define nsaddr nsaddr_list[0]		/* for backward compatibility */
121 	char	*dnsrch[MAXDNSRCH + 1];	/* components of domain to search */
122 	/*char defdname[256]; - moved, was here */
123 	u_int8_t nscount;		/* (was: int) number of name servers */
124 	u_int8_t ndots;			/* (was: unsigned:4) threshold for initial abs. query */
125 	u_int8_t retrans;		/* (was: int) retransmission time interval */
126 	u_int8_t retry;			/* (was: int) number of times to retransmit */
127 #ifdef __UCLIBC_HAS_COMPAT_RES_STATE__
128 	/* googling for "_res.defdname" says it's still sometimes used.
129 	 * Pity. It's huge, I want to move it to EXTRA_COMPAT... */
130 	char	defdname[256];		/* default domain (deprecated) */
131 	u_int8_t nsort;			/* (was: unsigned:4) number of elements in sort_list[] */
132 	u_int16_t pfcode;		/* (was: ulong) RES_PRF_ flags. Used by dig. */
133 	unsigned short id;		/* current message id */
134 	int	res_h_errno;		/* last one set for this context */
135 	struct {
136 		struct in_addr	addr;
137 		u_int32_t	mask;
138 	} sort_list[MAXRESOLVSORT];
139 #endif
140 
141 	/* I assume that the intention is to store all
142 	 * DNS servers' addresses here, and duplicate in nsaddr_list[]
143 	 * those which have IPv4 address. In the case of IPv4 address
144 	 * _u._ext.nsaddrs[x] will point to some nsaddr_list[y],
145 	 * otherwise it will point into malloc'ed sockaddr_in6.
146 	 * nscount is the number of IPv4 addresses and _u._ext.nscount
147 	 * is the number of addresses of all kinds.
148 	 *
149 	 * If this differs from established usage and you need
150 	 * to change this, please describe how it is supposed to work.
151 	 */
152 	union {
153 		struct {
154 #ifdef __UCLIBC_HAS_IPV6__
155 			struct sockaddr_in6	*nsaddrs[MAXNS];
156 #endif
157 			u_int8_t		nscount; /* (was: u_int16_t) */
158 #ifdef __UCLIBC_HAS_COMPAT_RES_STATE__
159 			/* rather obscure, and differs in BSD and glibc */
160 			u_int16_t		nstimes[MAXNS];
161 			int			nssocks[MAXNS];
162 			u_int16_t		nscount6;
163 			u_int16_t		nsinit;
164 			/* glibc also has: */
165 			/*u_int16_t		nsmap[MAXNS];*/
166 			/*unsigned long long	initstamp;*/
167 #endif
168 		} _ext;
169 	} _u;
170 
171 #ifdef __UCLIBC_HAS_EXTRA_COMPAT_RES_STATE__
172 	/* Truly obscure stuff.
173 	 * Googling for "_res.XXX" for these members
174 	 * turned up basically empty */
175 	res_send_qhook qhook;		/* query hook */
176 	res_send_rhook rhook;		/* response hook */
177 	int	_vcsock;		/* PRIVATE: for res_send VC i/o */
178 	unsigned _flags;		/* PRIVATE: see below */
179 #endif
180 };
181 
182 typedef struct __res_state *res_state;
183 # undef __need_res_state
184 #endif
185 
186 #ifdef _RESOLV_H_
187 /*
188  * Revision information.  This is the release date in YYYYMMDD format.
189  * It can change every day so the right thing to do with it is use it
190  * in preprocessor commands such as "#if (__RES > 19931104)".  Do not
191  * compare for equality; rather, use it to determine whether your resolver
192  * is new enough to contain a certain feature.
193  */
194 
195 #if 0
196 #define	__RES	19991006
197 #else
198 #define	__RES	19960801
199 #endif
200 
201 /*
202  * Resolver configuration file.
203  * Normally not present, but may contain the address of the
204  * inital name server(s) to query and the domain search list.
205  */
206 
207 #ifndef _PATH_RESCONF
208 #define _PATH_RESCONF        "/etc/resolv.conf"
209 #endif
210 
211 struct res_sym {
212 	int	number;		/* Identifying number, like T_MX */
213 	char *	name;		/* Its symbolic name, like "MX" */
214 	char *	humanname;	/* Its fun name, like "mail exchanger" */
215 };
216 
217 /*
218  * Resolver flags (used to be discrete per-module statics ints).
219  */
220 #define	RES_F_VC	0x00000001	/* socket is TCP */
221 #define	RES_F_CONN	0x00000002	/* socket is connected */
222 
223 /* res_findzonecut() options */
224 #define	RES_EXHAUSTIVE	0x00000001	/* always do all queries */
225 
226 /*
227  * Resolver options (keep these in synch with res_debug.c, please)
228  * (which of these do we really implement??)
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 #if 0
249 #define RES_USEBSTRING	0x00040000	/* IPv6 reverse lookup with byte
250 					   strings */
251 #define RES_NOIP6DOTINT	0x00080000	/* Do not use .ip6.int in IPv6
252 					   reverse lookup */
253 
254 #define RES_DEFAULT	(RES_RECURSE|RES_DEFNAMES|RES_DNSRCH|RES_NOIP6DOTINT)
255 #else
256 #define RES_DEFAULT	(RES_RECURSE|RES_DEFNAMES|RES_DNSRCH)
257 #endif
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 /*			0x00008000	*/
278 
279 /* Things involving an internal (static) resolver context. */
280 __BEGIN_DECLS
281 extern struct __res_state *__res_state(void) __attribute__ ((__const__));
282 __END_DECLS
283 #define _res (*__res_state())
284 
285 #if 0
286 #define fp_nquery		__fp_nquery
287 #define fp_query		__fp_query
288 #define hostalias		__hostalias
289 #define p_query			__p_query
290 #endif
291 #define res_close		__res_close
292 #define res_init		__res_init
293 #if 0
294 #define res_isourserver		__res_isourserver
295 #endif
296 #define res_mkquery		__res_mkquery
297 #define res_query		__res_query
298 #define res_querydomain		__res_querydomain
299 #define res_search		__res_search
300 #if 0
301 #define res_send		__res_send
302 #endif
303 
304 __BEGIN_DECLS
305 #if 0
306 void		fp_nquery (const u_char *, int, FILE *) __THROW;
307 void		fp_query (const u_char *, FILE *) __THROW;
308 const char *	hostalias (const char *) __THROW;
309 void		p_query (const u_char *) __THROW;
310 #endif
311 #ifdef __UCLIBC_HAS_BSD_RES_CLOSE__
312 void		res_close (void) __THROW;
313 #endif
314 int		res_init (void) __THROW;
315 libc_hidden_proto(res_init)
316 #if 0
317 int		res_isourserver (const struct sockaddr_in *) __THROW;
318 #endif
319 int		res_mkquery (int, const char *, int, int, const u_char *,
320 			     int, const u_char *, u_char *, int) __THROW;
321 int		res_query (const char *, int, int, u_char *, int) __THROW;
322 libc_hidden_proto(res_query)
323 int		res_querydomain (const char *, const char *, int, int,
324 				 u_char *, int) __THROW;
325 libc_hidden_proto(res_querydomain)
326 int		res_search (const char *, int, int, u_char *, int) __THROW;
327 #if 0
328 int		res_send (const u_char *, int, u_char *, int) __THROW;
329 #endif
330 __END_DECLS
331 
332 #if 0
333 #define b64_ntop		__b64_ntop
334 #define b64_pton		__b64_pton
335 #define dn_count_labels		__dn_count_labels
336 #endif
337 #define dn_comp			__dn_comp
338 #define dn_expand		__dn_expand
339 #define dn_skipname		__dn_skipname
340 #define res_ninit		__res_ninit
341 #define res_nclose		__res_nclose
342 #if 0
343 #define fp_resstat		__fp_resstat
344 #define loc_aton		__loc_aton
345 #define loc_ntoa		__loc_ntoa
346 #define p_cdname		__p_cdname
347 #define p_cdnname		__p_cdnname
348 #define p_class			__p_class
349 #define p_fqname		__p_fqname
350 #define p_fqnname		__p_fqnname
351 #define p_option		__p_option
352 #define p_secstodate		__p_secstodate
353 #define p_section		__p_section
354 #define p_time			__p_time
355 #define p_type			__p_type
356 #define p_rcode			__p_rcode
357 #define putlong			__putlong
358 #define putshort		__putshort
359 #define res_dnok		__res_dnok
360 #define res_hnok		__res_hnok
361 #define res_hostalias		__res_hostalias
362 #define res_mailok		__res_mailok
363 #define res_nameinquery		__res_nameinquery
364 #define res_nmkquery		__res_nmkquery
365 #define res_npquery		__res_npquery
366 #define res_nquery		__res_nquery
367 #define res_nquerydomain	__res_nquerydomain
368 #define res_nsearch		__res_nsearch
369 #define res_nsend		__res_nsend
370 #define res_nisourserver	__res_nisourserver
371 #define res_ownok		__res_ownok
372 #define res_queriesmatch	__res_queriesmatch
373 #define res_randomid		__res_randomid
374 #define sym_ntop		__sym_ntop
375 #define sym_ntos		__sym_ntos
376 #define sym_ston		__sym_ston
377 #endif
378 __BEGIN_DECLS
379 #if 0
380 int		res_hnok (const char *) __THROW;
381 int		res_ownok (const char *) __THROW;
382 int		res_mailok (const char *) __THROW;
383 int		res_dnok (const char *) __THROW;
384 int		sym_ston (const struct res_sym *, const char *, int *) __THROW;
385 const char *	sym_ntos (const struct res_sym *, int, int *) __THROW;
386 const char *	sym_ntop (const struct res_sym *, int, int *) __THROW;
387 int		b64_ntop (u_char const *, size_t, char *, size_t) __THROW;
388 int		b64_pton (char const *, u_char *, size_t) __THROW;
389 int		loc_aton (const char *ascii, u_char *binary) __THROW;
390 const char *	loc_ntoa (const u_char *binary, char *ascii) __THROW;
391 void		putlong (u_int32_t, u_char *) __THROW;
392 void		putshort (u_int16_t, u_char *) __THROW;
393 const char *	p_class (int) __THROW;
394 const char *	p_time (u_int32_t) __THROW;
395 const char *	p_type (int) __THROW;
396 const char *	p_rcode (int) __THROW;
397 const u_char *	p_cdnname (const u_char *, const u_char *, int, FILE *)
398      __THROW;
399 const u_char *	p_cdname (const u_char *, const u_char *, FILE *) __THROW;
400 const u_char *	p_fqnname (const u_char *cp, const u_char *msg,
401 			   int, char *, int) __THROW;
402 const u_char *	p_fqname (const u_char *, const u_char *, FILE *) __THROW;
403 const char *	p_option (u_long option) __THROW;
404 char *		p_secstodate (u_long) __THROW;
405 int		dn_count_labels (const char *) __THROW;
406 #endif
407 int		dn_skipname (const u_char *, const u_char *) __THROW;
408 libc_hidden_proto(dn_skipname)
409 int		dn_comp (const char *, u_char *, int, u_char **, u_char **)
410      __THROW;
411 libc_hidden_proto(dn_comp)
412 int		dn_expand (const u_char *, const u_char *, const u_char *,
413 			   char *, int) __THROW;
414 libc_hidden_proto(dn_expand)
415 int		res_ninit (res_state) __THROW;
416 void		res_nclose (res_state) __THROW;
417 #if 0
418 u_int		res_randomid (void) __THROW;
419 int		res_nameinquery (const char *, int, int,
420 				 const u_char *, const u_char *) __THROW;
421 int		res_queriesmatch (const u_char *, const u_char *,
422 				  const u_char *, const u_char *) __THROW;
423 const char *	p_section (int section, int opcode) __THROW;
424 /* Things involving a resolver context. */
425 int		res_nisourserver (const res_state,
426 				  const struct sockaddr_in *) __THROW;
427 void		fp_resstat (const res_state, FILE *) __THROW;
428 void		res_npquery (const res_state, const u_char *, int, FILE *)
429      __THROW;
430 const char *	res_hostalias (const res_state, const char *, char *, size_t)
431      __THROW;
432 int		res_nquery (res_state, const char *, int, int, u_char *, int)
433      __THROW;
434 int		res_nsearch (res_state, const char *, int, int, u_char *, int)
435      __THROW;
436 int		res_nquerydomain (res_state, const char *, const char *, int,
437 				  int, u_char *, int) __THROW;
438 int		res_nmkquery (res_state, int, const char *, int, int,
439 			      const u_char *, int, const u_char *, u_char *,
440 			      int) __THROW;
441 int		res_nsend (res_state, const u_char *, int, u_char *, int)
442      __THROW;
443 #endif
444 __END_DECLS
445 
446 # if _LIBC
447 #  ifdef __UCLIBC_HAS_THREADS__
448 #   if defined __UCLIBC_HAS_TLS__ \
449 	       && (!defined NOT_IN_libc || defined IS_IN_libpthread)
450 #    undef _res
451 #    ifndef NOT_IN_libc
452 #     define __resp __libc_resp
453 #    endif
454 #    define _res (*__resp)
455 extern __thread struct __res_state *__resp attribute_tls_model_ie;
456 #   endif
457 #  else
458 #   undef _res
459 #   define _res (*__resp)
460 extern struct __res_state *__resp;
461 #  endif /* __UCLIBC_HAS_THREADS__ */
462 # endif /* _LIBC */
463 
464 #endif /* _RESOLV_H_ */
465 
466 #endif /* !_RESOLV_H_ */
467