5628df75 |
1 | /* |
18d49d56 |
2 | * adns.h |
3 | * - adns user-visible API (single-threaded, without any locking) |
4 | */ |
5 | /* |
d942707d |
6 | * |
7 | * This file is |
8 | * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> |
9 | * |
10 | * It is part of adns, which is |
11 | * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> |
12 | * Copyright (C) 1999 Tony Finch <dot@dotat.at> |
e576be50 |
13 | * |
14 | * This program is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2, or (at your option) |
17 | * any later version. |
18 | * |
19 | * This program is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
d942707d |
23 | * |
24 | * |
25 | * For the benefit of certain LGPL'd `omnibus' software which provides |
26 | * a uniform interface to various things including adns, I make the |
27 | * following additional licence. I do this because the GPL would |
28 | * otherwise force either the omnibus software to be GPL'd or for the |
29 | * adns-using part to be distributed separately. |
30 | * |
31 | * So, you may also redistribute and/or modify adns.h (but only the |
32 | * public header file adns.h and not any other part of adns) under the |
33 | * terms of the GNU Library General Public License as published by the |
34 | * Free Software Foundation; either version 2 of the License, or (at |
35 | * your option) any later version. |
e576be50 |
36 | * |
d942707d |
37 | * Note that adns itself is GPL'd. Authors of adns-using applications |
38 | * with GPL-incompatible licences, and people who distribute adns with |
39 | * applications where the whole distribution is not GPL'd, are still |
40 | * likely to be in violation of the GPL. Anyone who wants to do this |
41 | * should contact Ian Jackson. Please note that to avoid encouraging |
42 | * people to infringe the GPL as it applies the body of adns, I think |
43 | * that if you take advantage of the special exception to redistribute |
44 | * just adns.h under the LGPL, you should retain this paragraph in its |
45 | * place in the appropriate copyright statements. |
46 | * |
47 | * |
48 | * You should have received a copy of the GNU General Public License, |
49 | * or the GNU Library General Public License, as appropriate, along |
50 | * with this program; if not, write to the Free Software Foundation, |
a719a4be |
51 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
52 | * |
d942707d |
53 | * |
a719a4be |
54 | * $Id$ |
e576be50 |
55 | */ |
a17d3a1d |
56 | |
57 | #ifndef ADNS_H_INCLUDED |
58 | #define ADNS_H_INCLUDED |
02b47faa |
59 | #ifdef __cplusplus |
60 | extern "C" { /* I really dislike this - iwj. */ |
61 | #endif |
a17d3a1d |
62 | |
4353a5c4 |
63 | #include <stdio.h> |
64 | |
964344fc |
65 | #include <sys/socket.h> |
66 | #include <netinet/in.h> |
636b69b1 |
67 | #include <sys/types.h> |
68 | #include <sys/time.h> |
69 | #include <unistd.h> |
964344fc |
70 | |
0d417fc2 |
71 | #ifndef AF_INET6 |
72 | #include "adns-in6fake.h" |
73 | #endif |
74 | |
09957b1c |
75 | /* All struct in_addr anywhere in adns are in NETWORK byte order. */ |
76 | |
964344fc |
77 | typedef struct adns__state *adns_state; |
78 | typedef struct adns__query *adns_query; |
a17d3a1d |
79 | |
80 | typedef enum { |
37e28fde |
81 | adns_if_noenv= 0x0001, /* do not look at environment */ |
82 | adns_if_noerrprint= 0x0002, /* never print output to stderr (_debug overrides) */ |
83 | adns_if_noserverwarn= 0x0004, /* do not warn to stderr about duff nameservers etc */ |
ddfda861 |
84 | adns_if_debug= 0x0008, /* enable all output to stderr plus debug msgs */ |
5f67bb7b |
85 | adns_if_logpid= 0x0080, /* include pid in diagnostic output */ |
37e28fde |
86 | adns_if_noautosys= 0x0010, /* do not make syscalls at every opportunity */ |
88372443 |
87 | adns_if_eintr= 0x0020, /* allow _wait and _synchronous to return EINTR */ |
ac868fa8 |
88 | adns_if_nosigpipe= 0x0040, /* applic has SIGPIPE set to SIG_IGN, do not protect */ |
3e2e5fab |
89 | adns_if_checkc_entex= 0x0100, /* do consistency checks on entry/exit to adns funcs */ |
0aa7cba0 |
90 | adns_if_checkc_freq= 0x0300 /* do consistency checks very frequently (slow!) */ |
0d417fc2 |
91 | adns_if_ip6= 0x1000 /* make default be adns_qf_ip6 */ |
a17d3a1d |
92 | } adns_initflags; |
93 | |
94 | typedef enum { |
b365d68a |
95 | adns_qf_search= 0x00000001, /* use the searchlist */ |
96 | adns_qf_usevc= 0x00000002, /* use a virtual circuit (TCP connection) */ |
97 | adns_qf_owner= 0x00000004, /* fill in the owner field in the answer */ |
8af5175d |
98 | adns_qf_quoteok_query= 0x00000010, /* allow special chars in query domain */ |
b365d68a |
99 | adns_qf_quoteok_cname= 0x00000000, /* allow ... in CNAME we go via - now default */ |
100 | adns_qf_quoteok_anshost= 0x00000040, /* allow ... in things supposed to be 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 */ |
0d417fc2 |
104 | adns_qf_ip6= 0x00001000, /* return addrs as AF_INET6 in all cases */ |
105 | adns_qf_ip6mixed= 0x00002000, /* return mixture of AF_INET4 and AF_INET6 */ |
106 | adns_qf_ip4= 0x00003000, /* never return AF_INET6, even with _if_ip6 */ |
b365d68a |
107 | adns__qf_internalmask= 0x0ff00000 |
a17d3a1d |
108 | } adns_queryflags; |
109 | |
0d417fc2 |
110 | /* IPv6 support: |
111 | * adns_if_ip6 has the effect of changing the default from |
112 | * adns_qf_ip4 to adns_qf_ip6. |
113 | * |
114 | * query type _qf__ip4 _qf_ip6mixed _qf_ip6 |
115 | * |
116 | * _r_addr A? => AF_INET AAAA? => AF_INET6 AAAA? => AF_INET6 |
117 | * else fail else A? => AF_INET else A? => AF_INET6 |
118 | * |
119 | * _r_a A => AF_INET A => AF_INET A => AF_INET6 |
120 | * |
121 | * _r_aaaa AAAA => AF_INET6 AAAA => AF_INET6 AAAA => AF_INET6 |
122 | * |
123 | * Ie, |
124 | * _ip4: only A lookups will be done, and everything is |
125 | * returned as AF_INET addresses; |
126 | * _ip6mixed: will look for AAAA records first, and if there |
127 | * are any, return them as AF_INET6, otherwise like _ip4. |
128 | * _ip6: like _ip6mixed, but will return even IPv4 addresses in |
129 | * IPv6-mapped form inside AF_INET6, for all query types. |
130 | * |
131 | * Furthermore, there are configuration options which can prevent the |
132 | * use of either AAAA or A records for _r_addr; so it is safe to use |
133 | * _qf_ip6 and _r_addr without checking explicitly whether the host |
134 | * has IPv6 connectivity. |
135 | * |
136 | * Applications which do not support IPv4 should set none of these |
137 | * flags. Applications which have been `naively' converted to use |
138 | * AF_INET6 throughout should set adns_if_ip6. Applications which |
139 | * know what they are doing should know which flags to set :-). |
140 | */ |
141 | |
a17d3a1d |
142 | typedef enum { |
350d37d9 |
143 | adns__rrt_typemask= 0x0ffff, |
ddfda861 |
144 | adns__qtf_deref= 0x10000, /* dereference domains and perhaps produce extra data */ |
145 | adns__qtf_mail822= 0x20000, /* make mailboxes be in RFC822 rcpt field format */ |
ddfda861 |
146 | |
350d37d9 |
147 | adns_r_none= 0, |
ddfda861 |
148 | |
350d37d9 |
149 | adns_r_a= 1, |
ddfda861 |
150 | |
350d37d9 |
151 | adns_r_ns_raw= 2, |
152 | adns_r_ns= adns_r_ns_raw|adns__qtf_deref, |
ddfda861 |
153 | |
350d37d9 |
154 | adns_r_cname= 5, |
ddfda861 |
155 | |
350d37d9 |
156 | adns_r_soa_raw= 6, |
ddfda861 |
157 | adns_r_soa= adns_r_soa_raw|adns__qtf_mail822, |
ddfda861 |
158 | |
350d37d9 |
159 | adns_r_ptr_raw= 12, |
160 | adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref, |
ddfda861 |
161 | |
350d37d9 |
162 | adns_r_hinfo= 13, |
ddfda861 |
163 | |
350d37d9 |
164 | adns_r_mx_raw= 15, |
165 | adns_r_mx= adns_r_mx_raw|adns__qtf_deref, |
ddfda861 |
166 | |
350d37d9 |
167 | adns_r_txt= 16, |
ddfda861 |
168 | |
350d37d9 |
169 | adns_r_rp_raw= 17, |
4353a5c4 |
170 | adns_r_rp= adns_r_rp_raw|adns__qtf_mail822, |
828d89bd |
171 | |
0d417fc2 |
172 | adns_r_aaaa= 28, |
173 | |
174 | adns_r_srv_raw= 33, |
175 | adns_r_srv= adns_r_srv_raw|adns__qtf_deref, |
176 | |
828d89bd |
177 | adns_r_addr= adns_r_a|adns__qtf_deref |
ddfda861 |
178 | |
a17d3a1d |
179 | } adns_rrtype; |
180 | |
b365d68a |
181 | /* |
182 | * In queries without qf_quoteok_*, all domains must have standard |
183 | * legal syntax, or you get adns_s_querydomainvalid (if the query |
184 | * domain contains bad characters) or adns_s_answerdomaininvalid (if |
185 | * the answer contains bad characters). |
186 | * |
187 | * In queries _with_ qf_quoteok_*, domains in the query or response |
188 | * may contain any characters, quoted according to RFC1035 5.1. On |
189 | * input to adns, the char* is a pointer to the interior of a " |
8af5175d |
190 | * delimited string, except that " may appear in it unquoted. On |
191 | * output, the char* is a pointer to a string which would be legal |
192 | * either inside or outside " delimiters; any character which isn't |
193 | * legal in a hostname (ie alphanumeric or hyphen) or one of _ / + |
194 | * (the three other punctuation characters commonly abused in domain |
195 | * names) will be quoted, as \X if it is a printing ASCII character or |
196 | * \DDD otherwise. |
197 | * |
198 | * (The characters which will be unquoted are the printing 7-bit ASCII |
199 | * characters except the punctuation characters " ( ) @ ; $ \ |
200 | |
201 | * I.e. unquoted characters are alphanumerics, and the following |
202 | * punctuation characters: ! # % ^ & * - _ = + [ ] { } |
964344fc |
203 | * |
b365d68a |
204 | * If the query goes via a CNAME then the canonical name (ie, the |
205 | * thing that the CNAME record refers to) is usually allowed to |
206 | * contain any characters, which will be quoted as above. With |
207 | * adns_qf_quotefail_cname you get adns_s_answerdomaininvalid when |
208 | * this happens. (This is a change from version 0.4 and earlier, in |
209 | * which failing the query was the default, and you had to say |
210 | * adns_qf_quoteok_cname to avoid this; that flag is now deprecated.) |
211 | * |
212 | * In version 0.4 and earlier, asking for _raw records containing |
213 | * mailboxes without specifying _qf_quoteok_anshost was silly. This |
214 | * is no longer the case. In this version only parts of responses |
215 | * that are actually supposed to be hostnames will be refused by |
216 | * default if quote-requiring characters are found. |
217 | */ |
218 | |
219 | /* |
220 | * If you ask for an RR which contains domains which are actually |
221 | * encoded mailboxes, and don't ask for the _raw version, then adns |
222 | * returns the mailbox formatted suitably for an RFC822 recipient |
223 | * header field. The particular format used is that if the mailbox |
224 | * requires quoting according to the rules in RFC822 then the |
225 | * local-part is quoted in double quotes, which end at the next |
226 | * unescaped double quote. (\ is the escape char, and is doubled, and |
227 | * is used to escape only \ and ".) Otherwise the local-part is |
228 | * presented as-is. In any case this is followed by an @ and the |
229 | * domain. The domain will not contain any characters not legal in |
230 | * hostnames. adns will protect the application from local parts |
231 | * containing control characters - these appear to be legal according |
232 | * to RFC822 but are clearly a bad idea. |
233 | * |
234 | * If you ask for the domain with _raw then _no_ checking is done |
235 | * (even on the host part, regardless of adns_qf_quoteok_anshost), and |
236 | * you just get the domain name in master file format. |
237 | * |
238 | * If no mailbox is supplied the returned string will be `.' in either |
239 | * caswe. |
964344fc |
240 | */ |
241 | |
a17d3a1d |
242 | typedef enum { |
243 | adns_s_ok, |
ea1e31e3 |
244 | |
245 | /* locally induced errors */ |
246 | adns_s_nomemory, |
247 | adns_s_unknownrrtype, |
620c146d |
248 | adns_s_systemfail, |
249 | |
250 | adns_s_max_localfail= 29, |
ea1e31e3 |
251 | |
252 | /* remotely induced errors, detected locally */ |
37e28fde |
253 | adns_s_timeout, |
4bec51a4 |
254 | adns_s_allservfail, |
ec477b9e |
255 | adns_s_norecurse, |
ea1e31e3 |
256 | adns_s_invalidresponse, |
257 | adns_s_unknownformat, |
620c146d |
258 | |
259 | adns_s_max_remotefail= 59, |
ea1e31e3 |
260 | |
261 | /* remotely induced errors, reported by remote server to us */ |
262 | adns_s_rcodeservfail, |
263 | adns_s_rcodeformaterror, |
264 | adns_s_rcodenotimplemented, |
265 | adns_s_rcoderefused, |
266 | adns_s_rcodeunknown, |
620c146d |
267 | |
b9de380c |
268 | adns_s_max_tempfail= 99, |
ea1e31e3 |
269 | |
270 | /* remote configuration errors */ |
271 | adns_s_inconsistent, /* PTR gives domain whose A does not exist and match */ |
272 | adns_s_prohibitedcname, /* CNAME found where eg A expected (not if _qf_loosecname) */ |
273 | adns_s_answerdomaininvalid, |
274 | adns_s_answerdomaintoolong, |
275 | adns_s_invaliddata, |
276 | |
277 | adns_s_max_misconfig= 199, |
278 | |
ea1e31e3 |
279 | /* permanent problems with the query */ |
280 | adns_s_querydomainwrong, |
281 | adns_s_querydomaininvalid, |
282 | adns_s_querydomaintoolong, |
283 | |
284 | adns_s_max_misquery= 299, |
285 | |
286 | /* permanent errors */ |
a17d3a1d |
287 | adns_s_nxdomain, |
226c5eef |
288 | adns_s_nodata, |
289 | |
290 | adns_s_max_permfail= 499 |
ea1e31e3 |
291 | |
a17d3a1d |
292 | } adns_status; |
293 | |
e8c505a5 |
294 | typedef struct { |
828d89bd |
295 | int len; |
296 | union { |
297 | struct sockaddr sa; |
298 | struct sockaddr_in inet; |
0d417fc2 |
299 | struct sockaddr_in6 inet6; |
828d89bd |
300 | } addr; |
551ff40f |
301 | } adns_rr_addr; |
828d89bd |
302 | |
303 | typedef struct { |
1dfe95d8 |
304 | char *host; |
84fe28db |
305 | adns_status astatus; |
306 | int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */ |
551ff40f |
307 | adns_rr_addr *addrs; |
c7836bc9 |
308 | } adns_rr_hostaddr; |
4353a5c4 |
309 | |
310 | typedef struct { |
9ec44266 |
311 | char *(array[2]); |
4353a5c4 |
312 | } adns_rr_strpair; |
313 | |
314 | typedef struct { |
315 | int i; |
1dfe95d8 |
316 | adns_rr_hostaddr ha; |
c7836bc9 |
317 | } adns_rr_inthostaddr; |
4353a5c4 |
318 | |
319 | typedef struct { |
e062dcae |
320 | /* Used both for mx_raw, in which case i is the preference and str the domain, |
321 | * and for txt, in which case each entry has i for the `text' length, |
322 | * and str for the data (which will have had an extra nul appended |
323 | * so that if it was plain text it is now a null-terminated string). |
324 | */ |
4353a5c4 |
325 | int i; |
326 | char *str; |
327 | } adns_rr_intstr; |
328 | |
329 | typedef struct { |
9ec44266 |
330 | adns_rr_intstr array[2]; |
331 | } adns_rr_intstrpair; |
332 | |
333 | typedef struct { |
334 | char *mname, *rname; |
4353a5c4 |
335 | unsigned long serial, refresh, retry, expire, minimum; |
336 | } adns_rr_soa; |
84fe28db |
337 | |
338 | typedef struct { |
0d417fc2 |
339 | unsigned short priority; |
340 | unsigned short weight; |
341 | unsigned short port; |
342 | adns_rr_hostaddr ha; |
343 | } adns_rr_srv; |
344 | |
345 | typedef struct { |
346 | unsigned short priority; |
347 | unsigned short weight; |
348 | unsigned short port; |
349 | char *target; |
350 | } adns_rr_srvraw; |
351 | |
352 | typedef struct { |
a17d3a1d |
353 | adns_status status; |
354 | char *cname; /* always NULL if query was for CNAME records */ |
4b2c4f8a |
355 | char *owner; /* only set if requested in query flags, and may be 0 on error anyway */ |
86e7b8d9 |
356 | adns_rrtype type; /* guaranteed to be same as in query */ |
73dba56e |
357 | time_t expires; /* expiry time, defined only if _s_ok, nxdomain or nodata. NOT TTL! */ |
b365d68a |
358 | int nrrs, rrsz; /* nrrs is 0 if an error occurs */ |
a17d3a1d |
359 | union { |
8e5b0abb |
360 | void *untyped; |
361 | unsigned char *bytes; |
c7836bc9 |
362 | char *(*str); /* ns_raw, cname, ptr, ptr_raw */ |
363 | adns_rr_intstr *(*manyistr); /* txt (list of strings ends with i=-1, str=0) */ |
551ff40f |
364 | adns_rr_addr *addr; /* addr */ |
c7836bc9 |
365 | struct in_addr *inaddr; /* a */ |
0d417fc2 |
366 | struct in6_addr *inaddr6; /* aaaa */ |
c7836bc9 |
367 | adns_rr_hostaddr *hostaddr; /* ns */ |
9ec44266 |
368 | adns_rr_intstrpair *intstrpair; /* hinfo */ |
369 | adns_rr_strpair *strpair; /* rp, rp_raw */ |
c7836bc9 |
370 | adns_rr_inthostaddr *inthostaddr; /* mx */ |
371 | adns_rr_intstr *intstr; /* mx_raw */ |
372 | adns_rr_soa *soa; /* soa, soa_raw */ |
0d417fc2 |
373 | adns_rr_srv *srv; /* srv */ |
374 | adns_rr_srvraw *srvraw; /* srv_raw */ |
a17d3a1d |
375 | } rrs; |
e8c505a5 |
376 | } adns_answer; |
a17d3a1d |
377 | |
378 | /* Memory management: |
379 | * adns_state and adns_query are actually pointers to malloc'd state; |
380 | * On submission questions are copied, including the owner domain; |
4353a5c4 |
381 | * Answers are malloc'd as a single piece of memory; pointers in the |
382 | * answer struct point into further memory in the answer. |
a17d3a1d |
383 | * query_io: |
384 | * Must always be non-null pointer; |
385 | * If *query_io is 0 to start with then any query may be returned; |
386 | * If *query_io is !0 adns_query then only that query may be returned. |
d3eea642 |
387 | * If the call is successful, *query_io, *answer_r, and *context_r |
388 | * will all be set. |
a17d3a1d |
389 | * Errors: |
620c146d |
390 | * Return values are 0 or an errno value. |
391 | * |
392 | * For _init, _init_strcfg, _submit and _synchronous, system errors |
393 | * (eg, failure to create sockets, malloc failure, etc.) return errno |
394 | * values. |
395 | * |
396 | * For _wait and _check failures are reported in the answer |
226c5eef |
397 | * structure, and only 0, ESRCH or (for _check) EAGAIN is |
620c146d |
398 | * returned: if no (appropriate) requests are done adns_check returns |
226c5eef |
399 | * EAGAIN; if no (appropriate) requests are outstanding both |
620c146d |
400 | * adns_query and adns_wait return ESRCH. |
401 | * |
402 | * Additionally, _wait can return EINTR if you set adns_if_eintr. |
403 | * |
404 | * All other errors (nameserver failure, timed out connections, &c) |
405 | * are returned in the status field of the answer. After a |
406 | * successful _wait or _check, if status is nonzero then nrrs will be |
407 | * 0, otherwise it will be >0. type will always be the type |
408 | * requested. |
a17d3a1d |
409 | */ |
410 | |
e563872a |
411 | int adns_init(adns_state *newstate_r, adns_initflags flags, |
36369543 |
412 | FILE *diagfile /*0=>stderr*/); |
413 | |
e563872a |
414 | int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags, |
36369543 |
415 | FILE *diagfile /*0=>discard*/, const char *configtext); |
c8c7c813 |
416 | |
417 | /* Configuration: |
418 | * adns_init reads /etc/resolv.conf, which is expected to be (broadly |
fb7fbb66 |
419 | * speaking) in the format expected by libresolv, and then |
420 | * /etc/resolv-adns.conf if it exists. adns_init_strcfg is instead |
421 | * passed a string which is interpreted as if it were the contents of |
422 | * resolv.conf or resolv-adns.conf. In general, configuration which |
423 | * is set later overrides any that is set earlier. |
c8c7c813 |
424 | * |
fb7fbb66 |
425 | * Standard directives understood in resolv[-adns].conf: |
c8c7c813 |
426 | * |
427 | * nameserver <address> |
428 | * Must be followed by the IP address of a nameserver. Several |
429 | * nameservers may be specified, and they will be tried in the order |
430 | * found. There is a compiled in limit, currently 5, on the number |
431 | * of nameservers. (libresolv supports only 3 nameservers.) |
432 | * |
433 | * search <domain> ... |
434 | * Specifies the search list for queries which specify |
435 | * adns_qf_search. This is a list of domains to append to the query |
436 | * domain. The query domain will be tried as-is either before all |
437 | * of these or after them, depending on the ndots option setting |
438 | * (see below). |
439 | * |
440 | * domain <domain> |
441 | * This is present only for backward compatibility with obsolete |
442 | * versions of libresolv. It should not be used, and is interpreted |
443 | * by adns as if it were `search' - note that this is subtly |
444 | * different to libresolv's interpretation of this directive. |
445 | * |
446 | * sortlist <addr>/<mask> ... |
447 | * Should be followed by a sequence of IP-address and netmask pairs, |
448 | * separated by spaces. They may be specified as |
449 | * eg. 172.30.206.0/24 or 172.30.206.0/255.255.255.0. Currently up |
450 | * to 15 pairs may be specified (but note that libresolv only |
451 | * supports up to 10). |
452 | * |
453 | * options |
454 | * Should followed by one or more options, separated by spaces. |
455 | * Each option consists of an option name, followed by optionally |
456 | * a colon and a value. Options are listed below. |
457 | * |
fb7fbb66 |
458 | * Non-standard directives understood in resolv[-adns].conf: |
c8c7c813 |
459 | * |
460 | * clearnameservers |
461 | * Clears the list of nameservers, so that further nameserver lines |
462 | * start again from the beginning. |
463 | * |
464 | * include <filename> |
465 | * The specified file will be read. |
466 | * |
fb7fbb66 |
467 | * Additionally, adns will ignore lines in resolv[-adns].conf which |
468 | * start with a #. |
c8c7c813 |
469 | * |
470 | * Standard options understood: |
471 | * |
472 | * debug |
473 | * Enables debugging output from the resolver, which will be written |
474 | * to stderr. |
475 | * |
476 | * ndots:<count> |
477 | * Affects whether queries with adns_qf_search will be tried first |
478 | * without adding domains from the searchlist, or whether the bare |
479 | * query domain will be tried last. Queries which contain at least |
480 | * <count> dots will be tried bare first. The default is 1. |
481 | * |
482 | * Non-standard options understood: |
483 | * |
484 | * adns_checkc:none |
485 | * adns_checkc:entex |
486 | * adns_checkc:freq |
487 | * Changes the consistency checking frequency; this overrides the |
488 | * setting of adns_if_check_entex, adns_if_check_freq, or neither, |
489 | * in the flags passed to adns_init. |
0d417fc2 |
490 | * |
491 | * in6only |
492 | * in4only |
493 | * Return only IPv6, respectively only IPv4 addresses, in |
494 | * _rr_addr's. This may result in an adns_s_nodata error, if the |
495 | * application only supports, or the remote host only has, the wrong |
496 | * kind of address. |
c8c7c813 |
497 | * |
498 | * There are a number of environment variables which can modify the |
499 | * behaviour of adns. They take effect only if adns_init is used, and |
500 | * the caller of adns_init can disable them using adns_if_noenv. In |
501 | * each case there is both a FOO and an ADNS_FOO; the latter is |
502 | * interpreted later so that it can override the former. Unless |
503 | * otherwise stated, environment variables are interpreted after |
fb7fbb66 |
504 | * resolv[-adns].conf are read, in the order they are listed here. |
c8c7c813 |
505 | * |
506 | * RES_CONF, ADNS_RES_CONF |
507 | * A filename, whose contets are in the format of resolv.conf. |
508 | * |
509 | * RES_CONF_TEXT, ADNS_RES_CONF_TEXT |
510 | * A string in the format of resolv.conf. |
511 | * |
512 | * RES_OPTIONS, ADNS_RES_OPTIONS |
513 | * These are parsed as if they appeared in the `options' line of a |
514 | * resolv.conf. In addition to being parsed at this point in the |
515 | * sequence, they are also parsed at the very beginning before |
516 | * resolv.conf or any other environment variables are read, so that |
517 | * any debug option can affect the processing of the configuration. |
518 | * |
519 | * LOCALDOMAIN, ADNS_LOCALDOMAIN |
520 | * These are interpreted as if their contents appeared in a `search' |
521 | * line in resolv.conf. |
522 | */ |
a17d3a1d |
523 | |
524 | int adns_synchronous(adns_state ads, |
525 | const char *owner, |
526 | adns_rrtype type, |
e563872a |
527 | adns_queryflags flags, |
9d95094c |
528 | adns_answer **answer_r); |
e8c505a5 |
529 | |
530 | /* NB: if you set adns_if_noautosys then _submit and _check do not |
620c146d |
531 | * make any system calls; you must use some of the asynch-io event |
532 | * processing functions to actually get things to happen. |
e8c505a5 |
533 | */ |
a17d3a1d |
534 | |
535 | int adns_submit(adns_state ads, |
536 | const char *owner, |
537 | adns_rrtype type, |
e563872a |
538 | adns_queryflags flags, |
a17d3a1d |
539 | void *context, |
964344fc |
540 | adns_query *query_r); |
a17d3a1d |
541 | |
3ccea6ee |
542 | /* The owner should be quoted in master file format. */ |
543 | |
964344fc |
544 | int adns_check(adns_state ads, |
a17d3a1d |
545 | adns_query *query_io, |
9d95094c |
546 | adns_answer **answer_r, |
547 | void **context_r); |
a17d3a1d |
548 | |
549 | int adns_wait(adns_state ads, |
550 | adns_query *query_io, |
9d95094c |
551 | adns_answer **answer_r, |
552 | void **context_r); |
a17d3a1d |
553 | |
940356bd |
554 | /* same as adns_wait but uses poll(2) internally */ |
555 | int adns_wait_poll(adns_state ads, |
556 | adns_query *query_io, |
557 | adns_answer **answer_r, |
558 | void **context_r); |
559 | |
3955725c |
560 | void adns_cancel(adns_query query); |
a17d3a1d |
561 | |
620c146d |
562 | /* The adns_query you get back from _submit is valid (ie, can be |
563 | * legitimately passed into adns functions) until it is returned by |
564 | * adns_check or adns_wait, or passed to adns_cancel. After that it |
565 | * must not be used. You can rely on it not being reused until the |
566 | * first adns_submit or _transact call using the same adns_state after |
567 | * it became invalid, so you may compare it for equality with other |
568 | * query handles until you next call _query or _transact. |
636b69b1 |
569 | * |
570 | * _submit and _synchronous return ENOSYS if they don't understand the |
571 | * query type. |
e576be50 |
572 | */ |
a17d3a1d |
573 | |
b365d68a |
574 | int adns_submit_reverse(adns_state ads, |
575 | const struct sockaddr *addr, |
576 | adns_rrtype type, |
e563872a |
577 | adns_queryflags flags, |
b365d68a |
578 | void *context, |
579 | adns_query *query_r); |
d7449548 |
580 | /* type must be _r_ptr or _r_ptr_raw. _qf_search is ignored. |
0d417fc2 |
581 | * addr->sa_family must be AF_INET or AF_INET6 you get ENOSYS. |
582 | */ |
583 | |
584 | int adns_getaddrinfo(adns_state ads, |
585 | const char *name, /* Eg, "www.example.coom" */ |
586 | const char *service, /* Eg, "http" */ |
587 | const char *protocol, /* Eg, "tcp" */ |
588 | unsigned short defaultport, /* Eg, 80 */ |
589 | adns_queryflags flags, |
590 | adns_answer **answer_r, int *invented_r); |
591 | /* Does an SRV lookup (RFC2052). If this fails, tries an AAAA or A |
592 | * lookup instead, and if found uses getservbyname to find the port |
593 | * number (or failing that, uses defaultport). In the `fallback' |
594 | * case, will invent an SRV record with have priority and weight == 0 |
595 | * and set *invented_r to 1; if real SRV records were found, will set |
596 | * *invented_r to 0. invented_r may be null but answer_r may not be. |
597 | * If _getaddrinfo returns nonzero, *answer_r and/or *invented_r may |
598 | * or may not have been overwritten and should not be used. |
599 | * |
600 | * NB, like adns_synchronous, can fail either by returning an errno |
601 | * value, or by returning an adns_answer with ->nrrs==0 and |
602 | * ->status!=0. |
603 | * |
604 | * You have to write two loops when using the returned value, an outer |
605 | * one to loop over the returned SRV's, and an inner one to loop over |
606 | * the addresses for each one. |
d7449548 |
607 | */ |
b365d68a |
608 | |
2b1c6979 |
609 | int adns_submit_reverse_any(adns_state ads, |
610 | const struct sockaddr *addr, |
611 | const char *rzone, |
612 | adns_rrtype type, |
613 | adns_queryflags flags, |
614 | void *context, |
615 | adns_query *query_r); |
616 | /* For RBL-style reverse `zone's; look up |
617 | * <reversed-address>.<zone> |
618 | * Any type is allowed. _qf_search is ignored. |
619 | * addr->sa_family must be AF_INET or you get ENOSYS. |
620 | */ |
621 | |
620c146d |
622 | void adns_finish(adns_state ads); |
e576be50 |
623 | /* You may call this even if you have queries outstanding; |
624 | * they will be cancelled. |
625 | */ |
a17d3a1d |
626 | |
964344fc |
627 | |
958ad1f0 |
628 | void adns_forallqueries_begin(adns_state ads); |
8ce38e76 |
629 | adns_query adns_forallqueries_next(adns_state ads, void **context_r); |
620c146d |
630 | /* Iterator functions, which you can use to loop over the outstanding |
958ad1f0 |
631 | * (submitted but not yet successfuly checked/waited) queries. |
a8768e80 |
632 | * |
958ad1f0 |
633 | * You can only have one iteration going at once. You may call _begin |
634 | * at any time; after that, an iteration will be in progress. You may |
635 | * only call _next when an iteration is in progress - anything else |
636 | * may coredump. The iteration remains in progress until _next |
637 | * returns 0, indicating that all the queries have been walked over, |
638 | * or ANY other adns function is called with the same adns_state (or a |
639 | * query in the same adns_state). There is no need to explicitly |
640 | * finish an iteration. |
641 | * |
8ce38e76 |
642 | * context_r may be 0. *context_r may not be set when _next returns 0. |
964344fc |
643 | */ |
a17d3a1d |
644 | |
28de6442 |
645 | void adns_checkconsistency(adns_state ads, adns_query qu); |
3e2e5fab |
646 | /* Checks the consistency of adns's internal data structures. |
647 | * If any error is found, the program will abort(). |
28de6442 |
648 | * You may pass 0 for qu; if you pass non-null then additional checks |
649 | * are done to make sure that qu is a valid query. |
3e2e5fab |
650 | */ |
651 | |
620c146d |
652 | /* |
653 | * Example expected/legal calling sequence for submit/check/wait: |
a17d3a1d |
654 | * adns_init |
655 | * adns_submit 1 |
656 | * adns_submit 2 |
657 | * adns_submit 3 |
658 | * adns_wait 1 |
226c5eef |
659 | * adns_check 3 -> EAGAIN |
a17d3a1d |
660 | * adns_wait 2 |
661 | * adns_wait 3 |
662 | * .... |
663 | * adns_finish |
620c146d |
664 | */ |
665 | |
666 | /* |
667 | * Entrypoints for generic asynch io: |
668 | * (these entrypoints are not very useful except in combination with * |
669 | * some of the other I/O model calls which can tell you which fds to |
670 | * be interested in): |
671 | * |
672 | * Note that any adns call may cause adns to open and close fds, so |
673 | * you must call beforeselect or beforepoll again just before |
674 | * blocking, or you may not have an up-to-date list of it's fds. |
675 | */ |
676 | |
677 | int adns_processany(adns_state ads); |
678 | /* Gives adns flow-of-control for a bit. This will never block, and |
679 | * can be used with any threading/asynch-io model. If some error |
680 | * occurred which might cause an event loop to spin then the errno |
681 | * value is returned. |
682 | */ |
683 | |
684 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now); |
685 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now); |
686 | int adns_processexceptional(adns_state ads, int fd, const struct timeval *now); |
687 | /* Gives adns flow-of-control so that it can process incoming data |
688 | * from, or send outgoing data via, fd. Very like _processany. If it |
689 | * returns zero then fd will no longer be readable or writeable |
690 | * (unless of course more data has arrived since). adns will _only_ |
0a106d94 |
691 | * use that fd and only in the manner specified, regardless of whether |
620c146d |
692 | * adns_if_noautosys was specified. |
693 | * |
694 | * adns_processexceptional should be called when select(2) reports an |
695 | * exceptional condition, or poll(2) reports POLLPRI. |
696 | * |
697 | * It is fine to call _processreabable or _processwriteable when the |
698 | * fd is not ready, or with an fd that doesn't belong to adns; it will |
699 | * then just return 0. |
700 | * |
701 | * If some error occurred which might prevent an event loop to spin |
702 | * then the errno value is returned. |
703 | */ |
704 | |
705 | void adns_processtimeouts(adns_state ads, const struct timeval *now); |
706 | /* Gives adns flow-of-control so that it can process any timeouts |
707 | * which might have happened. Very like _processreadable/writeable. |
708 | * |
709 | * now may be 0; if it isn't, *now must be the current time, recently |
710 | * obtained from gettimeofday. |
711 | */ |
712 | |
713 | void adns_firsttimeout(adns_state ads, |
714 | struct timeval **tv_mod, struct timeval *tv_buf, |
715 | struct timeval now); |
716 | /* Asks adns when it would first like the opportunity to time |
717 | * something out. now must be the current time, from gettimeofday. |
718 | * |
719 | * If tv_mod points to 0 then tv_buf must be non-null, and |
720 | * _firsttimeout will fill in *tv_buf with the time until the first |
721 | * timeout, and make *tv_mod point to tv_buf. If adns doesn't have |
722 | * anything that might need timing out it will leave *tv_mod as 0. |
723 | * |
724 | * If *tv_mod is not 0 then tv_buf is not used. adns will update |
725 | * *tv_mod if it has any earlier timeout, and leave it alone if it |
726 | * doesn't. |
727 | * |
728 | * This call will not actually do any I/O, or change the fds that adns |
729 | * is using. It always succeeds and never blocks. |
730 | */ |
731 | |
732 | void adns_globalsystemfailure(adns_state ads); |
733 | /* If serious problem(s) happen which globally affect your ability to |
734 | * interact properly with adns, or adns's ability to function |
735 | * properly, you or adns can call this function. |
736 | * |
737 | * All currently outstanding queries will be made to fail with |
738 | * adns_s_systemfail, and adns will close any stream sockets it has |
739 | * open. |
740 | * |
741 | * This is used by adns, for example, if gettimeofday() fails. |
742 | * Without this the program's event loop might start to spin ! |
743 | * |
744 | * This call will never block. |
745 | */ |
746 | |
747 | /* |
748 | * Entrypoints for select-loop based asynch io: |
749 | */ |
750 | |
751 | void adns_beforeselect(adns_state ads, int *maxfd, fd_set *readfds, |
752 | fd_set *writefds, fd_set *exceptfds, |
753 | struct timeval **tv_mod, struct timeval *tv_buf, |
754 | const struct timeval *now); |
755 | /* Find out file descriptors adns is interested in, and when it would |
756 | * like the opportunity to time something out. If you do not plan to |
757 | * block then tv_mod may be 0. Otherwise, tv_mod and tv_buf are as |
758 | * for adns_firsttimeout. readfds, writefds, exceptfds and maxfd_io may |
759 | * not be 0. |
760 | * |
06f8e611 |
761 | * If now is not 0 then this will never actually do any I/O, or |
620c146d |
762 | * change the fds that adns is using or the timeouts it wants. In any |
763 | * case it won't block. |
764 | */ |
765 | |
766 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, |
767 | const fd_set *writefds, const fd_set *exceptfds, |
768 | const struct timeval *now); |
769 | /* Gives adns flow-of-control for a bit; intended for use after |
770 | * select. This is just a fancy way of calling adns_processreadable/ |
771 | * writeable/timeouts as appropriate, as if select had returned the |
772 | * data being passed. Always succeeds. |
773 | */ |
774 | |
775 | /* |
776 | * Example calling sequence: |
a17d3a1d |
777 | * |
e8c505a5 |
778 | * adns_init _noautosys |
a17d3a1d |
779 | * loop { |
620c146d |
780 | * adns_beforeselect |
a17d3a1d |
781 | * select |
620c146d |
782 | * adns_afterselect |
e8c505a5 |
783 | * ... |
784 | * adns_submit / adns_check |
785 | * ... |
a17d3a1d |
786 | * } |
787 | */ |
788 | |
620c146d |
789 | /* |
790 | * Entrypoints for poll-loop based asynch io: |
791 | */ |
792 | |
793 | struct pollfd; |
794 | /* In case your system doesn't have it or you forgot to include |
795 | * <sys/poll.h>, to stop the following declarations from causing |
796 | * problems. If your system doesn't have poll then the following |
797 | * entrypoints will not be defined in libadns. Sorry ! |
798 | */ |
799 | |
800 | int adns_beforepoll(adns_state ads, struct pollfd *fds, int *nfds_io, int *timeout_io, |
801 | const struct timeval *now); |
802 | /* Finds out which fd's adns is interested in, and when it would like |
803 | * to be able to time things out. This is in a form suitable for use |
804 | * with poll(2). |
805 | * |
806 | * On entry, usually fds should point to at least *nfds_io structs. |
807 | * adns will fill up to that many structs will information for poll, |
808 | * and record in *nfds_io how many structs it filled. If it wants to |
809 | * listen for more structs then *nfds_io will be set to the number |
810 | * required and _beforepoll will return ERANGE. |
811 | * |
620c146d |
812 | * You may call _beforepoll with fds==0 and *nfds_io 0, in which case |
813 | * adns will fill in the number of fds that it might be interested in |
fc6a52ae |
814 | * in *nfds_io, and always return either 0 (if it is not interested in |
815 | * any fds) or ERANGE (if it is). |
816 | * |
c912639e |
817 | * NOTE that (unless now is 0) adns may acquire additional fds |
fc6a52ae |
818 | * from one call to the next, so you must put adns_beforepoll in a |
819 | * loop, rather than assuming that the second call (with the buffer |
820 | * size requested by the first) will not return ERANGE. |
620c146d |
821 | * |
822 | * adns only ever sets POLLIN, POLLOUT and POLLPRI in its pollfd |
823 | * structs, and only ever looks at those bits. POLLPRI is required to |
fc6a52ae |
824 | * detect TCP Urgent Data (which should not be used by a DNS server) |
620c146d |
825 | * so that adns can know that the TCP stream is now useless. |
826 | * |
827 | * In any case, *timeout_io should be a timeout value as for poll(2), |
828 | * which adns will modify downwards as required. If the caller does |
fc6a52ae |
829 | * not plan to block then *timeout_io should be 0 on entry, or |
830 | * alternatively, timeout_io may be 0. (Alternatively, the caller may |
831 | * use _beforeselect with timeout_io==0 to find out about file |
832 | * descriptors, and use _firsttimeout is used to find out when adns |
833 | * might want to time something out.) |
620c146d |
834 | * |
835 | * adns_beforepoll will return 0 on success, and will not fail for any |
836 | * reason other than the fds buffer being too small (ERANGE). |
837 | * |
c912639e |
838 | * This call will never actually do any I/O. If you supply the |
839 | * current time it will not change the fds that adns is using or the |
840 | * timeouts it wants. |
841 | * |
842 | * In any case this call won't block. |
620c146d |
843 | */ |
844 | |
845 | #define ADNS_POLLFDS_RECOMMENDED 2 |
846 | /* If you allocate an fds buf with at least RECOMMENDED entries then |
847 | * you are unlikely to need to enlarge it. You are recommended to do |
848 | * so if it's convenient. However, you must be prepared for adns to |
849 | * require more space than this. |
850 | */ |
851 | |
852 | void adns_afterpoll(adns_state ads, const struct pollfd *fds, int nfds, |
853 | const struct timeval *now); |
854 | /* Gives adns flow-of-control for a bit; intended for use after |
855 | * poll(2). fds and nfds should be the results from poll(). pollfd |
856 | * structs mentioning fds not belonging to adns will be ignored. |
857 | */ |
858 | |
859 | |
86e7b8d9 |
860 | adns_status adns_rr_info(adns_rrtype type, |
861 | const char **rrtname_r, const char **fmtname_r, |
862 | int *len_r, |
863 | const void *datap, char **data_r); |
b365d68a |
864 | /* |
b365d68a |
865 | * Get information about a query type, or convert reply data to a |
866 | * textual form. type must be specified, and the official name of the |
867 | * corresponding RR type will be returned in *rrtname_r, and |
868 | * information about the processing style in *fmtname_r. The length |
869 | * of the table entry in an answer for that type will be returned in |
870 | * in *len_r. Any or all of rrtname_r, fmtname_r and len_r may be 0. |
871 | * If fmtname_r is non-null then *fmtname_r may be null on return, |
872 | * indicating that no special processing is involved. |
873 | * |
874 | * data_r be must be non-null iff datap is. In this case *data_r will |
875 | * be set to point to a string pointing to a representation of the RR |
876 | * data in master file format. (The owner name, timeout, class and |
877 | * type will not be present - only the data part of the RR.) The |
878 | * memory will have been obtained from malloc() and must be freed by |
879 | * the caller. |
86e7b8d9 |
880 | * |
881 | * Usually this routine will succeed. Possible errors include: |
882 | * adns_s_nomemory |
ea1e31e3 |
883 | * adns_s_rrtypeunknown |
86e7b8d9 |
884 | * adns_s_invaliddata (*datap contained garbage) |
885 | * If an error occurs then no memory has been allocated, |
886 | * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined. |
b365d68a |
887 | * |
888 | * There are some adns-invented data formats which are not official |
889 | * master file formats. These include: |
890 | * |
891 | * Mailboxes if __qtf_mail822: these are just included as-is. |
892 | * |
893 | * Addresses (adns_rr_addr): these may be of pretty much any type. |
894 | * The representation is in two parts: first, a word for the address |
895 | * family (ie, in AF_XXX, the XXX), and then one or more items for the |
896 | * address itself, depending on the format. For an IPv4 address the |
897 | * syntax is INET followed by the dotted quad (from inet_ntoa). |
898 | * Currently only IPv4 is supported. |
899 | * |
a6f1dc92 |
900 | * Text strings (as in adns_rr_txt) appear inside double quotes, and |
901 | * use \" and \\ to represent " and \, and \xHH to represent |
902 | * characters not in the range 32-126. |
903 | * |
b365d68a |
904 | * Hostname with addresses (adns_rr_hostaddr): this consists of the |
a6f1dc92 |
905 | * hostname, as usual, followed by the adns_status value, as an |
906 | * abbreviation, and then a descriptive string (encoded as if it were |
907 | * a piece of text), for the address lookup, followed by zero or more |
06f8e611 |
908 | * addresses enclosed in ( and ). If the result was a temporary |
b365d68a |
909 | * failure, then a single ? appears instead of the ( ). If the |
06f8e611 |
910 | * result was a permanent failure then an empty pair of parentheses |
b365d68a |
911 | * appears (which a space in between). For example, one of the NS |
a6f1dc92 |
912 | * records for greenend.org.uk comes out like |
913 | * ns.chiark.greenend.org.uk ok "OK" ( INET 195.224.76.132 ) |
b365d68a |
914 | * an MX referring to a nonexistent host might come out like: |
a6f1dc92 |
915 | * 50 sun2.nsfnet-relay.ac.uk nxdomain "No such domain" ( ) |
b365d68a |
916 | * and if nameserver information is not available you might get: |
a6f1dc92 |
917 | * dns2.spong.dyn.ml.org timeout "DNS query timed out" ? |
86e7b8d9 |
918 | */ |
919 | |
31144a72 |
920 | const char *adns_strerror(adns_status st); |
9da4a044 |
921 | const char *adns_errabbrev(adns_status st); |
ac77ffc1 |
922 | const char *adns_errtypeabbrev(adns_status st); |
620c146d |
923 | /* Like strerror but for adns_status values. adns_errabbrev returns |
924 | * the abbreviation of the error - eg, for adns_s_timeout it returns |
ac77ffc1 |
925 | * "timeout". adns_errtypeabbrev returns the abbreviation of the |
926 | * error class: ie, for values up to adns_s_max_XXX it will return the |
927 | * string XXX. You MUST NOT call these functions with status values |
620c146d |
928 | * not returned by the same adns library. |
929 | */ |
31144a72 |
930 | |
02b47faa |
931 | #ifdef __cplusplus |
932 | } /* end of extern "C" */ |
933 | #endif |
a17d3a1d |
934 | #endif |