f3efc943 |
1 | /* |
2 | * adns.h |
5448fc9f |
3 | * - adns user-visible API |
f3efc943 |
4 | */ |
5bb95567 |
5 | /* |
a79ac5ba |
6 | * |
7 | * This file is |
39f45e7e |
8 | * Copyright (C) 1997-2000,2003,2006 Ian Jackson |
a79ac5ba |
9 | * |
10 | * It is part of adns, which is |
39f45e7e |
11 | * Copyright (C) 1997-2000,2003,2006 Ian Jackson |
12 | * Copyright (C) 1999-2000,2003,2006 Tony Finch |
13 | * Copyright (C) 1991 Massachusetts Institute of Technology |
14 | * |
98db6da3 |
15 | * This program is free software; you can redistribute it and/or modify |
16 | * it under the terms of the GNU General Public License as published by |
17 | * the Free Software Foundation; either version 2, or (at your option) |
18 | * any later version. |
19 | * |
20 | * This program is distributed in the hope that it will be useful, |
21 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
22 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
23 | * GNU General Public License for more details. |
a79ac5ba |
24 | * |
25 | * |
c6826df6 |
26 | * For the benefit of certain LGPL'd `omnibus' software which |
27 | * provides a uniform interface to various things including adns, I |
28 | * make the following additional licence. I do this because the GPL |
29 | * would otherwise force either the omnibus software to be GPL'd or |
30 | * the adns-using part to be distributed separately. |
a79ac5ba |
31 | * |
c6826df6 |
32 | * So: you may also redistribute and/or modify adns.h (but only the |
a79ac5ba |
33 | * public header file adns.h and not any other part of adns) under the |
34 | * terms of the GNU Library General Public License as published by the |
35 | * Free Software Foundation; either version 2 of the License, or (at |
36 | * your option) any later version. |
98db6da3 |
37 | * |
a79ac5ba |
38 | * Note that adns itself is GPL'd. Authors of adns-using applications |
39 | * with GPL-incompatible licences, and people who distribute adns with |
40 | * applications where the whole distribution is not GPL'd, are still |
41 | * likely to be in violation of the GPL. Anyone who wants to do this |
42 | * should contact Ian Jackson. Please note that to avoid encouraging |
c6826df6 |
43 | * people to infringe the GPL as it applies to the body of adns, Ian |
44 | * thinks that if you take advantage of the special exception to |
45 | * redistribute just adns.h under the LGPL, you should retain this |
46 | * paragraph in its place in the appropriate copyright statements. |
a79ac5ba |
47 | * |
48 | * |
49 | * You should have received a copy of the GNU General Public License, |
50 | * or the GNU Library General Public License, as appropriate, along |
51 | * with this program; if not, write to the Free Software Foundation, |
3ff64957 |
52 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
53 | * |
a79ac5ba |
54 | * |
5448fc9f |
55 | * $Id: adns.h,v 1.96 2006/08/09 11:16:59 ian Exp $ |
5bb95567 |
56 | */ |
5db99a2e |
57 | |
58 | #ifndef ADNS_H_INCLUDED |
59 | #define ADNS_H_INCLUDED |
60 | |
d05cc330 |
61 | #include <stdio.h> |
86ea5e62 |
62 | #include <stdarg.h> |
d05cc330 |
63 | |
62ef4703 |
64 | #include <sys/types.h> |
e7afa27f |
65 | #include <sys/socket.h> |
66 | #include <netinet/in.h> |
125de2a9 |
67 | #include <sys/time.h> |
68 | #include <unistd.h> |
e7afa27f |
69 | |
368c83e4 |
70 | #ifdef __cplusplus |
71 | extern "C" { /* I really dislike this - iwj. */ |
72 | #endif |
73 | |
8c3aa944 |
74 | /* All struct in_addr anywhere in adns are in NETWORK byte order. */ |
75 | |
e7afa27f |
76 | typedef struct adns__state *adns_state; |
77 | typedef struct adns__query *adns_query; |
5db99a2e |
78 | |
7a1f00f7 |
79 | typedef enum { /* In general, or together the desired flags: */ |
80 | adns_if_none= 0x0000,/* no flags. nicer than 0 for some compilers */ |
7aac35cd |
81 | adns_if_noenv= 0x0001,/* do not look at environment */ |
82 | adns_if_noerrprint= 0x0002,/* never print to stderr (_debug overrides) */ |
83 | adns_if_noserverwarn=0x0004,/* do not warn to stderr about duff servers etc */ |
84 | adns_if_debug= 0x0008,/* enable all output to stderr plus debug msgs */ |
85 | adns_if_logpid= 0x0080,/* include pid in diagnostic output */ |
86 | adns_if_noautosys= 0x0010,/* do not make syscalls at every opportunity */ |
87 | adns_if_eintr= 0x0020,/* allow _wait and _synchronous to return EINTR */ |
88 | adns_if_nosigpipe= 0x0040,/* applic has SIGPIPE ignored, do not protect */ |
89 | adns_if_checkc_entex=0x0100,/* consistency checks on entry/exit to adns fns */ |
90 | adns_if_checkc_freq= 0x0300 /* consistency checks very frequently (slow!) */ |
5db99a2e |
91 | } adns_initflags; |
92 | |
7a1f00f7 |
93 | typedef enum { /* In general, or together the desired flags: */ |
94 | adns_qf_none= 0x00000000,/* no flags */ |
7aac35cd |
95 | adns_qf_search= 0x00000001,/* use the searchlist */ |
96 | adns_qf_usevc= 0x00000002,/* use a virtual circuit (TCP conn) */ |
97 | adns_qf_owner= 0x00000004,/* fill in the owner field in the answer */ |
98 | adns_qf_quoteok_query= 0x00000010,/* allow special chars in query domain */ |
99 | adns_qf_quoteok_cname= 0x00000000,/* ... in CNAME we go via (now default) */ |
100 | adns_qf_quoteok_anshost=0x00000040,/* ... in things supposedly hostnames */ |
101 | adns_qf_quotefail_cname=0x00000080,/* refuse if quote-req chars in CNAME we go via */ |
102 | adns_qf_cname_loose= 0x00000100,/* allow refs to CNAMEs - without, get _s_cname */ |
103 | adns_qf_cname_forbid= 0x00000200,/* don't follow CNAMEs, instead give _s_cname */ |
104 | adns__qf_internalmask= 0x0ff00000 |
5db99a2e |
105 | } adns_queryflags; |
106 | |
107 | typedef enum { |
7d0aaee4 |
108 | adns_rrt_typemask= 0x0ffff, |
3db6be73 |
109 | adns__qtf_deref= 0x10000,/* dereference domains; perhaps get extra data */ |
110 | adns__qtf_mail822= 0x20000,/* return mailboxes in RFC822 rcpt field fmt */ |
ba2dbede |
111 | |
112 | adns_r_unknown= 0x40000, |
113 | /* To use this, ask for records of type <rr-type-code>|adns_r_unknown. |
7d0aaee4 |
114 | * adns will not process the RDATA - you'll get adns_rr_byteblocks, |
115 | * where the int is the length and the unsigned char* points to the |
116 | * data. String representation of the RR data (by adns_rrinfo) is as in |
117 | * RFC3597. adns_rr_info will not return the type name in *rrtname_r |
118 | * (due to memory management problems); *fmtname_r will be set to |
119 | * "unknown". |
ba2dbede |
120 | * |
121 | * Do not specify adns_r_unknown along with a known RR type which |
7d0aaee4 |
122 | * requires domain name uncompression (see RFC3597 s4); domain names |
123 | * will not be uncompressed and the resulting data would be useless. |
124 | * Asking for meta-RR types via adns_r_unknown will not work properly |
125 | * either and may make adns complain about server misbehaviour, so don't |
126 | * do that. |
127 | * |
128 | * Don't forget adns_qf_quoteok if that's what you want. */ |
129 | |
7aac35cd |
130 | adns_r_none= 0, |
131 | |
132 | adns_r_a= 1, |
133 | |
134 | adns_r_ns_raw= 2, |
135 | adns_r_ns= adns_r_ns_raw|adns__qtf_deref, |
136 | |
137 | adns_r_cname= 5, |
138 | |
139 | adns_r_soa_raw= 6, |
140 | adns_r_soa= adns_r_soa_raw|adns__qtf_mail822, |
141 | |
4f6dbe69 |
142 | adns_r_ptr_raw= 12, /* do not mind PTR with wrong or missing A */ |
7aac35cd |
143 | adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref, |
144 | |
145 | adns_r_hinfo= 13, |
146 | |
147 | adns_r_mx_raw= 15, |
148 | adns_r_mx= adns_r_mx_raw|adns__qtf_deref, |
149 | |
150 | adns_r_txt= 16, |
151 | |
152 | adns_r_rp_raw= 17, |
153 | adns_r_rp= adns_r_rp_raw|adns__qtf_mail822, |
3db6be73 |
154 | |
155 | /* For SRV records, query domain without _qf_quoteok_query must look |
156 | * as expected from SRV RFC with hostname-like Name. _With_ |
157 | * _quoteok_query, any query domain is allowed. */ |
158 | adns_r_srv_raw= 33, |
159 | adns_r_srv= adns_r_srv_raw|adns__qtf_deref, |
7aac35cd |
160 | |
161 | adns_r_addr= adns_r_a|adns__qtf_deref |
162 | |
5db99a2e |
163 | } adns_rrtype; |
164 | |
0872e289 |
165 | /* |
166 | * In queries without qf_quoteok_*, all domains must have standard |
167 | * legal syntax, or you get adns_s_querydomainvalid (if the query |
168 | * domain contains bad characters) or adns_s_answerdomaininvalid (if |
169 | * the answer contains bad characters). |
170 | * |
171 | * In queries _with_ qf_quoteok_*, domains in the query or response |
172 | * may contain any characters, quoted according to RFC1035 5.1. On |
173 | * input to adns, the char* is a pointer to the interior of a " |
996e3b68 |
174 | * delimited string, except that " may appear in it unquoted. On |
175 | * output, the char* is a pointer to a string which would be legal |
176 | * either inside or outside " delimiters; any character which isn't |
177 | * legal in a hostname (ie alphanumeric or hyphen) or one of _ / + |
178 | * (the three other punctuation characters commonly abused in domain |
179 | * names) will be quoted, as \X if it is a printing ASCII character or |
180 | * \DDD otherwise. |
181 | * |
0872e289 |
182 | * If the query goes via a CNAME then the canonical name (ie, the |
183 | * thing that the CNAME record refers to) is usually allowed to |
184 | * contain any characters, which will be quoted as above. With |
185 | * adns_qf_quotefail_cname you get adns_s_answerdomaininvalid when |
186 | * this happens. (This is a change from version 0.4 and earlier, in |
187 | * which failing the query was the default, and you had to say |
188 | * adns_qf_quoteok_cname to avoid this; that flag is now deprecated.) |
189 | * |
190 | * In version 0.4 and earlier, asking for _raw records containing |
191 | * mailboxes without specifying _qf_quoteok_anshost was silly. This |
192 | * is no longer the case. In this version only parts of responses |
193 | * that are actually supposed to be hostnames will be refused by |
194 | * default if quote-requiring characters are found. |
195 | */ |
196 | |
197 | /* |
198 | * If you ask for an RR which contains domains which are actually |
199 | * encoded mailboxes, and don't ask for the _raw version, then adns |
200 | * returns the mailbox formatted suitably for an RFC822 recipient |
201 | * header field. The particular format used is that if the mailbox |
202 | * requires quoting according to the rules in RFC822 then the |
203 | * local-part is quoted in double quotes, which end at the next |
67ca39c8 |
204 | * unescaped double quote (\ is the escape char, and is doubled, and |
205 | * is used to escape only \ and "). If the local-part is legal |
206 | * without quoting according to RFC822, it is presented as-is. In any |
207 | * case the local-part is followed by an @ and the domain. The domain |
208 | * will not contain any characters not legal in hostnames. |
209 | * |
210 | * Unquoted local-parts may contain any printing 7-bit ASCII |
211 | * except the punctuation characters ( ) < > @ , ; : \ " [ ] |
212 | * I.e. they may contain alphanumerics, and the following |
213 | * punctuation characters: ! # % ^ & * - _ = + { } . |
214 | * |
215 | * adns will reject local parts containing control characters (byte |
216 | * values 0-31, 127-159, and 255) - these appear to be legal according |
abf5f52c |
217 | * to RFC822 (at least 0-127) but are clearly a bad idea. RFC1035 |
218 | * syntax does not make any distinction between a single RFC822 |
219 | * quoted-string containing full stops, and a series of quoted-strings |
220 | * separated by full stops; adns will return anything that isn't all |
221 | * valid atoms as a single quoted-string. RFC822 does not allow |
222 | * high-bit-set characters at all, but adns does allow them in |
223 | * local-parts, treating them as needing quoting. |
0872e289 |
224 | * |
225 | * If you ask for the domain with _raw then _no_ checking is done |
226 | * (even on the host part, regardless of adns_qf_quoteok_anshost), and |
227 | * you just get the domain name in master file format. |
228 | * |
229 | * If no mailbox is supplied the returned string will be `.' in either |
abf5f52c |
230 | * case. |
e7afa27f |
231 | */ |
232 | |
5db99a2e |
233 | typedef enum { |
7aac35cd |
234 | adns_s_ok, |
235 | |
236 | /* locally induced errors */ |
237 | adns_s_nomemory, |
238 | adns_s_unknownrrtype, |
239 | adns_s_systemfail, |
240 | |
241 | adns_s_max_localfail= 29, |
242 | |
243 | /* remotely induced errors, detected locally */ |
244 | adns_s_timeout, |
245 | adns_s_allservfail, |
246 | adns_s_norecurse, |
247 | adns_s_invalidresponse, |
248 | adns_s_unknownformat, |
249 | |
250 | adns_s_max_remotefail= 59, |
251 | |
252 | /* remotely induced errors, reported by remote server to us */ |
253 | adns_s_rcodeservfail, |
254 | adns_s_rcodeformaterror, |
255 | adns_s_rcodenotimplemented, |
256 | adns_s_rcoderefused, |
257 | adns_s_rcodeunknown, |
258 | |
259 | adns_s_max_tempfail= 99, |
260 | |
261 | /* remote configuration errors */ |
262 | adns_s_inconsistent, /* PTR gives domain whose A does not exist and match */ |
263 | adns_s_prohibitedcname, /* CNAME, but eg A expected (not if _qf_loosecname) */ |
264 | adns_s_answerdomaininvalid, |
265 | adns_s_answerdomaintoolong, |
266 | adns_s_invaliddata, |
267 | |
268 | adns_s_max_misconfig= 199, |
269 | |
270 | /* permanent problems with the query */ |
271 | adns_s_querydomainwrong, |
272 | adns_s_querydomaininvalid, |
273 | adns_s_querydomaintoolong, |
274 | |
275 | adns_s_max_misquery= 299, |
276 | |
277 | /* permanent errors */ |
278 | adns_s_nxdomain, |
279 | adns_s_nodata, |
280 | |
281 | adns_s_max_permfail= 499 |
282 | |
5db99a2e |
283 | } adns_status; |
284 | |
cd363ffd |
285 | typedef struct { |
286 | int len; |
287 | union { |
288 | struct sockaddr sa; |
289 | struct sockaddr_in inet; |
290 | } addr; |
bc01473e |
291 | } adns_rr_addr; |
cd363ffd |
292 | |
6927715a |
293 | typedef struct { |
26eb6bdc |
294 | char *host; |
6927715a |
295 | adns_status astatus; |
296 | int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */ |
bc01473e |
297 | adns_rr_addr *addrs; |
a1d2d0ed |
298 | } adns_rr_hostaddr; |
d05cc330 |
299 | |
300 | typedef struct { |
61093792 |
301 | char *(array[2]); |
d05cc330 |
302 | } adns_rr_strpair; |
303 | |
304 | typedef struct { |
305 | int i; |
26eb6bdc |
306 | adns_rr_hostaddr ha; |
a1d2d0ed |
307 | } adns_rr_inthostaddr; |
d05cc330 |
308 | |
309 | typedef struct { |
7aac35cd |
310 | /* Used both for mx_raw, in which case i is the preference and str |
311 | * the domain, and for txt, in which case each entry has i for the |
312 | * `text' length, and str for the data (which will have had an extra |
313 | * nul appended so that if it was plain text it is now a |
314 | * null-terminated string). |
f2ad23ee |
315 | */ |
d05cc330 |
316 | int i; |
317 | char *str; |
318 | } adns_rr_intstr; |
319 | |
320 | typedef struct { |
61093792 |
321 | adns_rr_intstr array[2]; |
322 | } adns_rr_intstrpair; |
323 | |
324 | typedef struct { |
325 | char *mname, *rname; |
d05cc330 |
326 | unsigned long serial, refresh, retry, expire, minimum; |
327 | } adns_rr_soa; |
6927715a |
328 | |
3db6be73 |
329 | typedef struct { |
330 | int priority, weight, port; |
331 | char *host; |
332 | } adns_rr_srvraw; |
333 | |
334 | typedef struct { |
335 | int priority, weight, port; |
336 | adns_rr_hostaddr ha; |
2248cdf4 |
337 | } adns_rr_srvha; |
3db6be73 |
338 | |
7d0aaee4 |
339 | typedef struct { |
340 | int len; |
341 | unsigned char *data; |
342 | } adns_rr_byteblock; |
343 | |
5617a135 |
344 | typedef struct { |
5db99a2e |
345 | adns_status status; |
346 | char *cname; /* always NULL if query was for CNAME records */ |
7aac35cd |
347 | char *owner; /* only set if req'd in query flags; maybe 0 on error anyway */ |
1e9efa71 |
348 | adns_rrtype type; /* guaranteed to be same as in query */ |
7aac35cd |
349 | time_t expires;/*abs time. def only if _s_ok, nxdomain or nodata. NOT TTL!*/ |
0872e289 |
350 | int nrrs, rrsz; /* nrrs is 0 if an error occurs */ |
5db99a2e |
351 | union { |
965c9782 |
352 | void *untyped; |
353 | unsigned char *bytes; |
7aac35cd |
354 | char *(*str); /* ns_raw, cname, ptr, ptr_raw */ |
355 | adns_rr_intstr *(*manyistr); /* txt (list strs ends with i=-1, str=0)*/ |
356 | adns_rr_addr *addr; /* addr */ |
357 | struct in_addr *inaddr; /* a */ |
358 | adns_rr_hostaddr *hostaddr; /* ns */ |
359 | adns_rr_intstrpair *intstrpair; /* hinfo */ |
360 | adns_rr_strpair *strpair; /* rp, rp_raw */ |
361 | adns_rr_inthostaddr *inthostaddr;/* mx */ |
7d0aaee4 |
362 | adns_rr_intstr *intstr; /* mx_raw */ |
7aac35cd |
363 | adns_rr_soa *soa; /* soa, soa_raw */ |
3db6be73 |
364 | adns_rr_srvraw *srvraw; /* srv_raw */ |
2248cdf4 |
365 | adns_rr_srvha *srvha;/* srv */ |
7d0aaee4 |
366 | adns_rr_byteblock *byteblock; /* ...|unknown */ |
5db99a2e |
367 | } rrs; |
5617a135 |
368 | } adns_answer; |
5db99a2e |
369 | |
370 | /* Memory management: |
371 | * adns_state and adns_query are actually pointers to malloc'd state; |
372 | * On submission questions are copied, including the owner domain; |
d05cc330 |
373 | * Answers are malloc'd as a single piece of memory; pointers in the |
374 | * answer struct point into further memory in the answer. |
5db99a2e |
375 | * query_io: |
376 | * Must always be non-null pointer; |
377 | * If *query_io is 0 to start with then any query may be returned; |
378 | * If *query_io is !0 adns_query then only that query may be returned. |
9be46d86 |
379 | * If the call is successful, *query_io, *answer_r, and *context_r |
380 | * will all be set. |
5db99a2e |
381 | * Errors: |
74c94831 |
382 | * Return values are 0 or an errno value. |
383 | * |
384 | * For _init, _init_strcfg, _submit and _synchronous, system errors |
385 | * (eg, failure to create sockets, malloc failure, etc.) return errno |
032b6358 |
386 | * values. EINVAL from _init et al means the configuration file |
387 | * is erroneous and cannot be parsed. |
74c94831 |
388 | * |
389 | * For _wait and _check failures are reported in the answer |
c6f9dc7b |
390 | * structure, and only 0, ESRCH or (for _check) EAGAIN is |
74c94831 |
391 | * returned: if no (appropriate) requests are done adns_check returns |
c6f9dc7b |
392 | * EAGAIN; if no (appropriate) requests are outstanding both |
74c94831 |
393 | * adns_query and adns_wait return ESRCH. |
394 | * |
395 | * Additionally, _wait can return EINTR if you set adns_if_eintr. |
396 | * |
397 | * All other errors (nameserver failure, timed out connections, &c) |
398 | * are returned in the status field of the answer. After a |
399 | * successful _wait or _check, if status is nonzero then nrrs will be |
400 | * 0, otherwise it will be >0. type will always be the type |
401 | * requested. |
5db99a2e |
402 | */ |
403 | |
5448fc9f |
404 | /* Threads: |
405 | * adns does not use any static modifiable state, so it |
406 | * is safe to call adns_init several times and then use the |
407 | * resulting adns_states concurrently. |
408 | * However, it is NOT safe to make simultaneous calls into |
409 | * adns using the same adns_state; a single adns_state must be used |
410 | * only by one thread at a time. You can solve this problem by |
411 | * having one adns_state per thread, or if that isn't feasible, you |
412 | * could maintain a pool of adns_states. Unfortunately neither of |
413 | * these approaches has optimal performance. |
414 | */ |
415 | |
edb95764 |
416 | int adns_init(adns_state *newstate_r, adns_initflags flags, |
d6b271ae |
417 | FILE *diagfile /*0=>stderr*/); |
418 | |
edb95764 |
419 | int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags, |
d6b271ae |
420 | FILE *diagfile /*0=>discard*/, const char *configtext); |
38fcb64a |
421 | |
86ea5e62 |
422 | typedef void adns_logcallbackfn(adns_state ads, void *logfndata, |
423 | const char *fmt, va_list al); |
424 | /* Will be called perhaps several times for each message; when the |
425 | * message is complete, the string implied by fmt and al will end in |
426 | * a newline. Log messages start with `adns debug:' or `adns |
427 | * warning:' or `adns:' (for errors), or `adns debug [PID]:' |
428 | * etc. if adns_if_logpid is set. */ |
429 | |
430 | int adns_init_logfn(adns_state *newstate_r, adns_initflags flags, |
431 | const char *configtext /*0=>use default config files*/, |
432 | adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */, |
433 | void *logfndata /*0 with logfn==0 => discard*/); |
434 | |
38fcb64a |
435 | /* Configuration: |
436 | * adns_init reads /etc/resolv.conf, which is expected to be (broadly |
45efc92a |
437 | * speaking) in the format expected by libresolv, and then |
438 | * /etc/resolv-adns.conf if it exists. adns_init_strcfg is instead |
439 | * passed a string which is interpreted as if it were the contents of |
440 | * resolv.conf or resolv-adns.conf. In general, configuration which |
441 | * is set later overrides any that is set earlier. |
38fcb64a |
442 | * |
45efc92a |
443 | * Standard directives understood in resolv[-adns].conf: |
38fcb64a |
444 | * |
445 | * nameserver <address> |
446 | * Must be followed by the IP address of a nameserver. Several |
447 | * nameservers may be specified, and they will be tried in the order |
448 | * found. There is a compiled in limit, currently 5, on the number |
449 | * of nameservers. (libresolv supports only 3 nameservers.) |
450 | * |
451 | * search <domain> ... |
452 | * Specifies the search list for queries which specify |
453 | * adns_qf_search. This is a list of domains to append to the query |
454 | * domain. The query domain will be tried as-is either before all |
455 | * of these or after them, depending on the ndots option setting |
456 | * (see below). |
457 | * |
458 | * domain <domain> |
459 | * This is present only for backward compatibility with obsolete |
460 | * versions of libresolv. It should not be used, and is interpreted |
461 | * by adns as if it were `search' - note that this is subtly |
462 | * different to libresolv's interpretation of this directive. |
463 | * |
464 | * sortlist <addr>/<mask> ... |
465 | * Should be followed by a sequence of IP-address and netmask pairs, |
466 | * separated by spaces. They may be specified as |
467 | * eg. 172.30.206.0/24 or 172.30.206.0/255.255.255.0. Currently up |
468 | * to 15 pairs may be specified (but note that libresolv only |
469 | * supports up to 10). |
470 | * |
471 | * options |
472 | * Should followed by one or more options, separated by spaces. |
473 | * Each option consists of an option name, followed by optionally |
474 | * a colon and a value. Options are listed below. |
475 | * |
45efc92a |
476 | * Non-standard directives understood in resolv[-adns].conf: |
38fcb64a |
477 | * |
478 | * clearnameservers |
479 | * Clears the list of nameservers, so that further nameserver lines |
480 | * start again from the beginning. |
481 | * |
482 | * include <filename> |
483 | * The specified file will be read. |
484 | * |
45efc92a |
485 | * Additionally, adns will ignore lines in resolv[-adns].conf which |
486 | * start with a #. |
38fcb64a |
487 | * |
488 | * Standard options understood: |
489 | * |
490 | * debug |
491 | * Enables debugging output from the resolver, which will be written |
492 | * to stderr. |
493 | * |
494 | * ndots:<count> |
495 | * Affects whether queries with adns_qf_search will be tried first |
496 | * without adding domains from the searchlist, or whether the bare |
497 | * query domain will be tried last. Queries which contain at least |
498 | * <count> dots will be tried bare first. The default is 1. |
499 | * |
500 | * Non-standard options understood: |
501 | * |
502 | * adns_checkc:none |
503 | * adns_checkc:entex |
504 | * adns_checkc:freq |
505 | * Changes the consistency checking frequency; this overrides the |
506 | * setting of adns_if_check_entex, adns_if_check_freq, or neither, |
507 | * in the flags passed to adns_init. |
508 | * |
509 | * There are a number of environment variables which can modify the |
510 | * behaviour of adns. They take effect only if adns_init is used, and |
511 | * the caller of adns_init can disable them using adns_if_noenv. In |
512 | * each case there is both a FOO and an ADNS_FOO; the latter is |
513 | * interpreted later so that it can override the former. Unless |
514 | * otherwise stated, environment variables are interpreted after |
45efc92a |
515 | * resolv[-adns].conf are read, in the order they are listed here. |
38fcb64a |
516 | * |
517 | * RES_CONF, ADNS_RES_CONF |
518 | * A filename, whose contets are in the format of resolv.conf. |
519 | * |
520 | * RES_CONF_TEXT, ADNS_RES_CONF_TEXT |
521 | * A string in the format of resolv.conf. |
522 | * |
523 | * RES_OPTIONS, ADNS_RES_OPTIONS |
524 | * These are parsed as if they appeared in the `options' line of a |
525 | * resolv.conf. In addition to being parsed at this point in the |
526 | * sequence, they are also parsed at the very beginning before |
527 | * resolv.conf or any other environment variables are read, so that |
528 | * any debug option can affect the processing of the configuration. |
529 | * |
530 | * LOCALDOMAIN, ADNS_LOCALDOMAIN |
531 | * These are interpreted as if their contents appeared in a `search' |
532 | * line in resolv.conf. |
533 | */ |
5db99a2e |
534 | |
535 | int adns_synchronous(adns_state ads, |
536 | const char *owner, |
537 | adns_rrtype type, |
edb95764 |
538 | adns_queryflags flags, |
9ab4dfce |
539 | adns_answer **answer_r); |
5617a135 |
540 | |
541 | /* NB: if you set adns_if_noautosys then _submit and _check do not |
74c94831 |
542 | * make any system calls; you must use some of the asynch-io event |
543 | * processing functions to actually get things to happen. |
5617a135 |
544 | */ |
5db99a2e |
545 | |
546 | int adns_submit(adns_state ads, |
547 | const char *owner, |
548 | adns_rrtype type, |
edb95764 |
549 | adns_queryflags flags, |
5db99a2e |
550 | void *context, |
e7afa27f |
551 | adns_query *query_r); |
5db99a2e |
552 | |
bcf33879 |
553 | /* The owner should be quoted in master file format. */ |
554 | |
e7afa27f |
555 | int adns_check(adns_state ads, |
5db99a2e |
556 | adns_query *query_io, |
9ab4dfce |
557 | adns_answer **answer_r, |
558 | void **context_r); |
5db99a2e |
559 | |
560 | int adns_wait(adns_state ads, |
561 | adns_query *query_io, |
9ab4dfce |
562 | adns_answer **answer_r, |
563 | void **context_r); |
5db99a2e |
564 | |
ef20fccf |
565 | /* same as adns_wait but uses poll(2) internally */ |
566 | int adns_wait_poll(adns_state ads, |
567 | adns_query *query_io, |
568 | adns_answer **answer_r, |
569 | void **context_r); |
570 | |
11c8bf9b |
571 | void adns_cancel(adns_query query); |
5db99a2e |
572 | |
74c94831 |
573 | /* The adns_query you get back from _submit is valid (ie, can be |
574 | * legitimately passed into adns functions) until it is returned by |
575 | * adns_check or adns_wait, or passed to adns_cancel. After that it |
576 | * must not be used. You can rely on it not being reused until the |
577 | * first adns_submit or _transact call using the same adns_state after |
578 | * it became invalid, so you may compare it for equality with other |
579 | * query handles until you next call _query or _transact. |
125de2a9 |
580 | * |
581 | * _submit and _synchronous return ENOSYS if they don't understand the |
582 | * query type. |
74c94831 |
583 | */ |
584 | |
0872e289 |
585 | int adns_submit_reverse(adns_state ads, |
586 | const struct sockaddr *addr, |
587 | adns_rrtype type, |
edb95764 |
588 | adns_queryflags flags, |
0872e289 |
589 | void *context, |
590 | adns_query *query_r); |
5e6342f0 |
591 | /* type must be _r_ptr or _r_ptr_raw. _qf_search is ignored. |
592 | * addr->sa_family must be AF_INET or you get ENOSYS. |
593 | */ |
0872e289 |
594 | |
d2f6d877 |
595 | int adns_submit_reverse_any(adns_state ads, |
596 | const struct sockaddr *addr, |
597 | const char *rzone, |
598 | adns_rrtype type, |
599 | adns_queryflags flags, |
600 | void *context, |
601 | adns_query *query_r); |
602 | /* For RBL-style reverse `zone's; look up |
603 | * <reversed-address>.<zone> |
604 | * Any type is allowed. _qf_search is ignored. |
605 | * addr->sa_family must be AF_INET or you get ENOSYS. |
606 | */ |
607 | |
74c94831 |
608 | void adns_finish(adns_state ads); |
98db6da3 |
609 | /* You may call this even if you have queries outstanding; |
610 | * they will be cancelled. |
611 | */ |
5db99a2e |
612 | |
e7afa27f |
613 | |
23dca174 |
614 | void adns_forallqueries_begin(adns_state ads); |
8f2aa812 |
615 | adns_query adns_forallqueries_next(adns_state ads, void **context_r); |
74c94831 |
616 | /* Iterator functions, which you can use to loop over the outstanding |
23dca174 |
617 | * (submitted but not yet successfuly checked/waited) queries. |
74c94831 |
618 | * |
23dca174 |
619 | * You can only have one iteration going at once. You may call _begin |
620 | * at any time; after that, an iteration will be in progress. You may |
621 | * only call _next when an iteration is in progress - anything else |
622 | * may coredump. The iteration remains in progress until _next |
623 | * returns 0, indicating that all the queries have been walked over, |
624 | * or ANY other adns function is called with the same adns_state (or a |
625 | * query in the same adns_state). There is no need to explicitly |
626 | * finish an iteration. |
627 | * |
8f2aa812 |
628 | * context_r may be 0. *context_r may not be set when _next returns 0. |
e7afa27f |
629 | */ |
5db99a2e |
630 | |
2ac463bf |
631 | void adns_checkconsistency(adns_state ads, adns_query qu); |
1389dc72 |
632 | /* Checks the consistency of adns's internal data structures. |
633 | * If any error is found, the program will abort(). |
2ac463bf |
634 | * You may pass 0 for qu; if you pass non-null then additional checks |
635 | * are done to make sure that qu is a valid query. |
1389dc72 |
636 | */ |
637 | |
74c94831 |
638 | /* |
639 | * Example expected/legal calling sequence for submit/check/wait: |
5db99a2e |
640 | * adns_init |
641 | * adns_submit 1 |
642 | * adns_submit 2 |
643 | * adns_submit 3 |
644 | * adns_wait 1 |
c6f9dc7b |
645 | * adns_check 3 -> EAGAIN |
5db99a2e |
646 | * adns_wait 2 |
647 | * adns_wait 3 |
648 | * .... |
649 | * adns_finish |
74c94831 |
650 | */ |
651 | |
652 | /* |
653 | * Entrypoints for generic asynch io: |
654 | * (these entrypoints are not very useful except in combination with * |
655 | * some of the other I/O model calls which can tell you which fds to |
656 | * be interested in): |
657 | * |
658 | * Note that any adns call may cause adns to open and close fds, so |
659 | * you must call beforeselect or beforepoll again just before |
660 | * blocking, or you may not have an up-to-date list of it's fds. |
661 | */ |
662 | |
663 | int adns_processany(adns_state ads); |
664 | /* Gives adns flow-of-control for a bit. This will never block, and |
665 | * can be used with any threading/asynch-io model. If some error |
666 | * occurred which might cause an event loop to spin then the errno |
667 | * value is returned. |
668 | */ |
669 | |
670 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now); |
671 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now); |
672 | int adns_processexceptional(adns_state ads, int fd, const struct timeval *now); |
673 | /* Gives adns flow-of-control so that it can process incoming data |
674 | * from, or send outgoing data via, fd. Very like _processany. If it |
675 | * returns zero then fd will no longer be readable or writeable |
676 | * (unless of course more data has arrived since). adns will _only_ |
7a1ae5ac |
677 | * use that fd and only in the manner specified, regardless of whether |
74c94831 |
678 | * adns_if_noautosys was specified. |
679 | * |
680 | * adns_processexceptional should be called when select(2) reports an |
681 | * exceptional condition, or poll(2) reports POLLPRI. |
682 | * |
683 | * It is fine to call _processreabable or _processwriteable when the |
684 | * fd is not ready, or with an fd that doesn't belong to adns; it will |
685 | * then just return 0. |
686 | * |
687 | * If some error occurred which might prevent an event loop to spin |
688 | * then the errno value is returned. |
689 | */ |
690 | |
691 | void adns_processtimeouts(adns_state ads, const struct timeval *now); |
692 | /* Gives adns flow-of-control so that it can process any timeouts |
693 | * which might have happened. Very like _processreadable/writeable. |
694 | * |
695 | * now may be 0; if it isn't, *now must be the current time, recently |
696 | * obtained from gettimeofday. |
697 | */ |
698 | |
699 | void adns_firsttimeout(adns_state ads, |
700 | struct timeval **tv_mod, struct timeval *tv_buf, |
701 | struct timeval now); |
702 | /* Asks adns when it would first like the opportunity to time |
703 | * something out. now must be the current time, from gettimeofday. |
704 | * |
705 | * If tv_mod points to 0 then tv_buf must be non-null, and |
706 | * _firsttimeout will fill in *tv_buf with the time until the first |
707 | * timeout, and make *tv_mod point to tv_buf. If adns doesn't have |
708 | * anything that might need timing out it will leave *tv_mod as 0. |
709 | * |
710 | * If *tv_mod is not 0 then tv_buf is not used. adns will update |
711 | * *tv_mod if it has any earlier timeout, and leave it alone if it |
712 | * doesn't. |
713 | * |
714 | * This call will not actually do any I/O, or change the fds that adns |
715 | * is using. It always succeeds and never blocks. |
716 | */ |
717 | |
718 | void adns_globalsystemfailure(adns_state ads); |
719 | /* If serious problem(s) happen which globally affect your ability to |
720 | * interact properly with adns, or adns's ability to function |
721 | * properly, you or adns can call this function. |
722 | * |
723 | * All currently outstanding queries will be made to fail with |
724 | * adns_s_systemfail, and adns will close any stream sockets it has |
725 | * open. |
726 | * |
727 | * This is used by adns, for example, if gettimeofday() fails. |
728 | * Without this the program's event loop might start to spin ! |
729 | * |
730 | * This call will never block. |
731 | */ |
732 | |
733 | /* |
734 | * Entrypoints for select-loop based asynch io: |
735 | */ |
736 | |
737 | void adns_beforeselect(adns_state ads, int *maxfd, fd_set *readfds, |
738 | fd_set *writefds, fd_set *exceptfds, |
739 | struct timeval **tv_mod, struct timeval *tv_buf, |
740 | const struct timeval *now); |
741 | /* Find out file descriptors adns is interested in, and when it would |
742 | * like the opportunity to time something out. If you do not plan to |
743 | * block then tv_mod may be 0. Otherwise, tv_mod and tv_buf are as |
744 | * for adns_firsttimeout. readfds, writefds, exceptfds and maxfd_io may |
745 | * not be 0. |
746 | * |
86ea5e62 |
747 | * If tv_mod is 0 on entry then this will never actually do any I/O, |
748 | * or change the fds that adns is using or the timeouts it wants. In |
749 | * any case it won't block, and it will set the timeout to zero if a |
750 | * query finishes in _beforeselect. |
74c94831 |
751 | */ |
752 | |
753 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, |
754 | const fd_set *writefds, const fd_set *exceptfds, |
755 | const struct timeval *now); |
756 | /* Gives adns flow-of-control for a bit; intended for use after |
757 | * select. This is just a fancy way of calling adns_processreadable/ |
758 | * writeable/timeouts as appropriate, as if select had returned the |
759 | * data being passed. Always succeeds. |
760 | */ |
761 | |
762 | /* |
763 | * Example calling sequence: |
5db99a2e |
764 | * |
5617a135 |
765 | * adns_init _noautosys |
5db99a2e |
766 | * loop { |
74c94831 |
767 | * adns_beforeselect |
5db99a2e |
768 | * select |
74c94831 |
769 | * adns_afterselect |
5617a135 |
770 | * ... |
771 | * adns_submit / adns_check |
772 | * ... |
5db99a2e |
773 | * } |
774 | */ |
775 | |
74c94831 |
776 | /* |
777 | * Entrypoints for poll-loop based asynch io: |
778 | */ |
779 | |
780 | struct pollfd; |
781 | /* In case your system doesn't have it or you forgot to include |
782 | * <sys/poll.h>, to stop the following declarations from causing |
783 | * problems. If your system doesn't have poll then the following |
784 | * entrypoints will not be defined in libadns. Sorry ! |
785 | */ |
786 | |
7aac35cd |
787 | int adns_beforepoll(adns_state ads, struct pollfd *fds, |
788 | int *nfds_io, int *timeout_io, |
74c94831 |
789 | const struct timeval *now); |
790 | /* Finds out which fd's adns is interested in, and when it would like |
791 | * to be able to time things out. This is in a form suitable for use |
792 | * with poll(2). |
793 | * |
794 | * On entry, usually fds should point to at least *nfds_io structs. |
795 | * adns will fill up to that many structs will information for poll, |
796 | * and record in *nfds_io how many structs it filled. If it wants to |
797 | * listen for more structs then *nfds_io will be set to the number |
798 | * required and _beforepoll will return ERANGE. |
799 | * |
74c94831 |
800 | * You may call _beforepoll with fds==0 and *nfds_io 0, in which case |
801 | * adns will fill in the number of fds that it might be interested in |
4f973eb5 |
802 | * in *nfds_io, and always return either 0 (if it is not interested in |
803 | * any fds) or ERANGE (if it is). |
804 | * |
dd9cf93b |
805 | * NOTE that (unless now is 0) adns may acquire additional fds |
4f973eb5 |
806 | * from one call to the next, so you must put adns_beforepoll in a |
807 | * loop, rather than assuming that the second call (with the buffer |
808 | * size requested by the first) will not return ERANGE. |
74c94831 |
809 | * |
810 | * adns only ever sets POLLIN, POLLOUT and POLLPRI in its pollfd |
811 | * structs, and only ever looks at those bits. POLLPRI is required to |
4f973eb5 |
812 | * detect TCP Urgent Data (which should not be used by a DNS server) |
74c94831 |
813 | * so that adns can know that the TCP stream is now useless. |
814 | * |
815 | * In any case, *timeout_io should be a timeout value as for poll(2), |
816 | * which adns will modify downwards as required. If the caller does |
4f973eb5 |
817 | * not plan to block then *timeout_io should be 0 on entry, or |
818 | * alternatively, timeout_io may be 0. (Alternatively, the caller may |
819 | * use _beforeselect with timeout_io==0 to find out about file |
820 | * descriptors, and use _firsttimeout is used to find out when adns |
821 | * might want to time something out.) |
74c94831 |
822 | * |
823 | * adns_beforepoll will return 0 on success, and will not fail for any |
824 | * reason other than the fds buffer being too small (ERANGE). |
825 | * |
dd9cf93b |
826 | * This call will never actually do any I/O. If you supply the |
827 | * current time it will not change the fds that adns is using or the |
828 | * timeouts it wants. |
829 | * |
830 | * In any case this call won't block. |
74c94831 |
831 | */ |
832 | |
833 | #define ADNS_POLLFDS_RECOMMENDED 2 |
834 | /* If you allocate an fds buf with at least RECOMMENDED entries then |
835 | * you are unlikely to need to enlarge it. You are recommended to do |
836 | * so if it's convenient. However, you must be prepared for adns to |
837 | * require more space than this. |
838 | */ |
839 | |
840 | void adns_afterpoll(adns_state ads, const struct pollfd *fds, int nfds, |
841 | const struct timeval *now); |
842 | /* Gives adns flow-of-control for a bit; intended for use after |
843 | * poll(2). fds and nfds should be the results from poll(). pollfd |
844 | * structs mentioning fds not belonging to adns will be ignored. |
845 | */ |
846 | |
847 | |
1e9efa71 |
848 | adns_status adns_rr_info(adns_rrtype type, |
849 | const char **rrtname_r, const char **fmtname_r, |
850 | int *len_r, |
851 | const void *datap, char **data_r); |
0872e289 |
852 | /* |
0872e289 |
853 | * Get information about a query type, or convert reply data to a |
854 | * textual form. type must be specified, and the official name of the |
855 | * corresponding RR type will be returned in *rrtname_r, and |
856 | * information about the processing style in *fmtname_r. The length |
857 | * of the table entry in an answer for that type will be returned in |
858 | * in *len_r. Any or all of rrtname_r, fmtname_r and len_r may be 0. |
859 | * If fmtname_r is non-null then *fmtname_r may be null on return, |
860 | * indicating that no special processing is involved. |
861 | * |
862 | * data_r be must be non-null iff datap is. In this case *data_r will |
863 | * be set to point to a string pointing to a representation of the RR |
864 | * data in master file format. (The owner name, timeout, class and |
865 | * type will not be present - only the data part of the RR.) The |
866 | * memory will have been obtained from malloc() and must be freed by |
867 | * the caller. |
1e9efa71 |
868 | * |
869 | * Usually this routine will succeed. Possible errors include: |
870 | * adns_s_nomemory |
9b86645c |
871 | * adns_s_rrtypeunknown |
1e9efa71 |
872 | * adns_s_invaliddata (*datap contained garbage) |
873 | * If an error occurs then no memory has been allocated, |
874 | * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined. |
0872e289 |
875 | * |
876 | * There are some adns-invented data formats which are not official |
877 | * master file formats. These include: |
878 | * |
879 | * Mailboxes if __qtf_mail822: these are just included as-is. |
880 | * |
881 | * Addresses (adns_rr_addr): these may be of pretty much any type. |
882 | * The representation is in two parts: first, a word for the address |
883 | * family (ie, in AF_XXX, the XXX), and then one or more items for the |
884 | * address itself, depending on the format. For an IPv4 address the |
885 | * syntax is INET followed by the dotted quad (from inet_ntoa). |
886 | * Currently only IPv4 is supported. |
887 | * |
0fb18816 |
888 | * Text strings (as in adns_rr_txt) appear inside double quotes, and |
889 | * use \" and \\ to represent " and \, and \xHH to represent |
890 | * characters not in the range 32-126. |
891 | * |
0872e289 |
892 | * Hostname with addresses (adns_rr_hostaddr): this consists of the |
0fb18816 |
893 | * hostname, as usual, followed by the adns_status value, as an |
894 | * abbreviation, and then a descriptive string (encoded as if it were |
895 | * a piece of text), for the address lookup, followed by zero or more |
eaf858ea |
896 | * addresses enclosed in ( and ). If the result was a temporary |
0872e289 |
897 | * failure, then a single ? appears instead of the ( ). If the |
eaf858ea |
898 | * result was a permanent failure then an empty pair of parentheses |
0872e289 |
899 | * appears (which a space in between). For example, one of the NS |
0fb18816 |
900 | * records for greenend.org.uk comes out like |
901 | * ns.chiark.greenend.org.uk ok "OK" ( INET 195.224.76.132 ) |
0872e289 |
902 | * an MX referring to a nonexistent host might come out like: |
0fb18816 |
903 | * 50 sun2.nsfnet-relay.ac.uk nxdomain "No such domain" ( ) |
0872e289 |
904 | * and if nameserver information is not available you might get: |
0fb18816 |
905 | * dns2.spong.dyn.ml.org timeout "DNS query timed out" ? |
1e9efa71 |
906 | */ |
907 | |
7f702335 |
908 | const char *adns_strerror(adns_status st); |
c2875680 |
909 | const char *adns_errabbrev(adns_status st); |
9e50e3ac |
910 | const char *adns_errtypeabbrev(adns_status st); |
74c94831 |
911 | /* Like strerror but for adns_status values. adns_errabbrev returns |
912 | * the abbreviation of the error - eg, for adns_s_timeout it returns |
9e50e3ac |
913 | * "timeout". adns_errtypeabbrev returns the abbreviation of the |
914 | * error class: ie, for values up to adns_s_max_XXX it will return the |
915 | * string XXX. You MUST NOT call these functions with status values |
74c94831 |
916 | * not returned by the same adns library. |
917 | */ |
7f702335 |
918 | |
62049492 |
919 | #ifdef __cplusplus |
920 | } /* end of extern "C" */ |
921 | #endif |
5db99a2e |
922 | #endif |