5bb95567 |
1 | /* |
f3efc943 |
2 | * adns.h |
3 | * - adns user-visible API (single-threaded, without any locking) |
4 | */ |
5 | /* |
a79ac5ba |
6 | * |
7 | * This file is |
67ca39c8 |
8 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
a79ac5ba |
9 | * |
10 | * It is part of adns, which is |
89435c42 |
11 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
c6826df6 |
12 | * Copyright (C) 1999-2000 Tony Finch <dot@dotat.at> |
98db6da3 |
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. |
a79ac5ba |
23 | * |
24 | * |
c6826df6 |
25 | * For the benefit of certain LGPL'd `omnibus' software which |
26 | * provides a uniform interface to various things including adns, I |
27 | * make the following additional licence. I do this because the GPL |
28 | * would otherwise force either the omnibus software to be GPL'd or |
29 | * the adns-using part to be distributed separately. |
a79ac5ba |
30 | * |
c6826df6 |
31 | * So: you may also redistribute and/or modify adns.h (but only the |
a79ac5ba |
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. |
98db6da3 |
36 | * |
a79ac5ba |
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 |
c6826df6 |
42 | * people to infringe the GPL as it applies to the body of adns, Ian |
43 | * thinks that if you take advantage of the special exception to |
44 | * redistribute just adns.h under the LGPL, you should retain this |
45 | * paragraph in its place in the appropriate copyright statements. |
a79ac5ba |
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, |
3ff64957 |
51 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
52 | * |
a79ac5ba |
53 | * |
7aac35cd |
54 | * $Id: adns.h,v 1.85 2003/06/22 14:34:37 ian Exp $ |
5bb95567 |
55 | */ |
5db99a2e |
56 | |
57 | #ifndef ADNS_H_INCLUDED |
58 | #define ADNS_H_INCLUDED |
59 | |
d05cc330 |
60 | #include <stdio.h> |
61 | |
62ef4703 |
62 | #include <sys/types.h> |
e7afa27f |
63 | #include <sys/socket.h> |
64 | #include <netinet/in.h> |
125de2a9 |
65 | #include <sys/time.h> |
66 | #include <unistd.h> |
e7afa27f |
67 | |
368c83e4 |
68 | #ifdef __cplusplus |
69 | extern "C" { /* I really dislike this - iwj. */ |
70 | #endif |
71 | |
8c3aa944 |
72 | /* All struct in_addr anywhere in adns are in NETWORK byte order. */ |
73 | |
e7afa27f |
74 | typedef struct adns__state *adns_state; |
75 | typedef struct adns__query *adns_query; |
5db99a2e |
76 | |
77 | typedef enum { |
7aac35cd |
78 | adns_if_noenv= 0x0001,/* do not look at environment */ |
79 | adns_if_noerrprint= 0x0002,/* never print to stderr (_debug overrides) */ |
80 | adns_if_noserverwarn=0x0004,/* do not warn to stderr about duff servers etc */ |
81 | adns_if_debug= 0x0008,/* enable all output to stderr plus debug msgs */ |
82 | adns_if_logpid= 0x0080,/* include pid in diagnostic output */ |
83 | adns_if_noautosys= 0x0010,/* do not make syscalls at every opportunity */ |
84 | adns_if_eintr= 0x0020,/* allow _wait and _synchronous to return EINTR */ |
85 | adns_if_nosigpipe= 0x0040,/* applic has SIGPIPE ignored, do not protect */ |
86 | adns_if_checkc_entex=0x0100,/* consistency checks on entry/exit to adns fns */ |
87 | adns_if_checkc_freq= 0x0300 /* consistency checks very frequently (slow!) */ |
5db99a2e |
88 | } adns_initflags; |
89 | |
90 | typedef enum { |
7aac35cd |
91 | adns_qf_search= 0x00000001,/* use the searchlist */ |
92 | adns_qf_usevc= 0x00000002,/* use a virtual circuit (TCP conn) */ |
93 | adns_qf_owner= 0x00000004,/* fill in the owner field in the answer */ |
94 | adns_qf_quoteok_query= 0x00000010,/* allow special chars in query domain */ |
95 | adns_qf_quoteok_cname= 0x00000000,/* ... in CNAME we go via (now default) */ |
96 | adns_qf_quoteok_anshost=0x00000040,/* ... in things supposedly hostnames */ |
97 | adns_qf_quotefail_cname=0x00000080,/* refuse if quote-req chars in CNAME we go via */ |
98 | adns_qf_cname_loose= 0x00000100,/* allow refs to CNAMEs - without, get _s_cname */ |
99 | adns_qf_cname_forbid= 0x00000200,/* don't follow CNAMEs, instead give _s_cname */ |
100 | adns__qf_internalmask= 0x0ff00000 |
5db99a2e |
101 | } adns_queryflags; |
102 | |
103 | typedef enum { |
7aac35cd |
104 | adns__rrt_typemask=0x0ffff, |
105 | adns__qtf_deref= 0x10000, /* dereference domains; perhaps get extra data */ |
106 | adns__qtf_mail822= 0x20000, /* return mailboxes in RFC822 rcpt field fmt */ |
107 | |
108 | adns_r_none= 0, |
109 | |
110 | adns_r_a= 1, |
111 | |
112 | adns_r_ns_raw= 2, |
113 | adns_r_ns= adns_r_ns_raw|adns__qtf_deref, |
114 | |
115 | adns_r_cname= 5, |
116 | |
117 | adns_r_soa_raw= 6, |
118 | adns_r_soa= adns_r_soa_raw|adns__qtf_mail822, |
119 | |
120 | adns_r_ptr_raw= 12, |
121 | adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref, |
122 | |
123 | adns_r_hinfo= 13, |
124 | |
125 | adns_r_mx_raw= 15, |
126 | adns_r_mx= adns_r_mx_raw|adns__qtf_deref, |
127 | |
128 | adns_r_txt= 16, |
129 | |
130 | adns_r_rp_raw= 17, |
131 | adns_r_rp= adns_r_rp_raw|adns__qtf_mail822, |
132 | |
133 | adns_r_addr= adns_r_a|adns__qtf_deref |
134 | |
5db99a2e |
135 | } adns_rrtype; |
136 | |
0872e289 |
137 | /* |
138 | * In queries without qf_quoteok_*, all domains must have standard |
139 | * legal syntax, or you get adns_s_querydomainvalid (if the query |
140 | * domain contains bad characters) or adns_s_answerdomaininvalid (if |
141 | * the answer contains bad characters). |
142 | * |
143 | * In queries _with_ qf_quoteok_*, domains in the query or response |
144 | * may contain any characters, quoted according to RFC1035 5.1. On |
145 | * input to adns, the char* is a pointer to the interior of a " |
996e3b68 |
146 | * delimited string, except that " may appear in it unquoted. On |
147 | * output, the char* is a pointer to a string which would be legal |
148 | * either inside or outside " delimiters; any character which isn't |
149 | * legal in a hostname (ie alphanumeric or hyphen) or one of _ / + |
150 | * (the three other punctuation characters commonly abused in domain |
151 | * names) will be quoted, as \X if it is a printing ASCII character or |
152 | * \DDD otherwise. |
153 | * |
0872e289 |
154 | * If the query goes via a CNAME then the canonical name (ie, the |
155 | * thing that the CNAME record refers to) is usually allowed to |
156 | * contain any characters, which will be quoted as above. With |
157 | * adns_qf_quotefail_cname you get adns_s_answerdomaininvalid when |
158 | * this happens. (This is a change from version 0.4 and earlier, in |
159 | * which failing the query was the default, and you had to say |
160 | * adns_qf_quoteok_cname to avoid this; that flag is now deprecated.) |
161 | * |
162 | * In version 0.4 and earlier, asking for _raw records containing |
163 | * mailboxes without specifying _qf_quoteok_anshost was silly. This |
164 | * is no longer the case. In this version only parts of responses |
165 | * that are actually supposed to be hostnames will be refused by |
166 | * default if quote-requiring characters are found. |
167 | */ |
168 | |
169 | /* |
170 | * If you ask for an RR which contains domains which are actually |
171 | * encoded mailboxes, and don't ask for the _raw version, then adns |
172 | * returns the mailbox formatted suitably for an RFC822 recipient |
173 | * header field. The particular format used is that if the mailbox |
174 | * requires quoting according to the rules in RFC822 then the |
175 | * local-part is quoted in double quotes, which end at the next |
67ca39c8 |
176 | * unescaped double quote (\ is the escape char, and is doubled, and |
177 | * is used to escape only \ and "). If the local-part is legal |
178 | * without quoting according to RFC822, it is presented as-is. In any |
179 | * case the local-part is followed by an @ and the domain. The domain |
180 | * will not contain any characters not legal in hostnames. |
181 | * |
182 | * Unquoted local-parts may contain any printing 7-bit ASCII |
183 | * except the punctuation characters ( ) < > @ , ; : \ " [ ] |
184 | * I.e. they may contain alphanumerics, and the following |
185 | * punctuation characters: ! # % ^ & * - _ = + { } . |
186 | * |
187 | * adns will reject local parts containing control characters (byte |
188 | * values 0-31, 127-159, and 255) - these appear to be legal according |
abf5f52c |
189 | * to RFC822 (at least 0-127) but are clearly a bad idea. RFC1035 |
190 | * syntax does not make any distinction between a single RFC822 |
191 | * quoted-string containing full stops, and a series of quoted-strings |
192 | * separated by full stops; adns will return anything that isn't all |
193 | * valid atoms as a single quoted-string. RFC822 does not allow |
194 | * high-bit-set characters at all, but adns does allow them in |
195 | * local-parts, treating them as needing quoting. |
0872e289 |
196 | * |
197 | * If you ask for the domain with _raw then _no_ checking is done |
198 | * (even on the host part, regardless of adns_qf_quoteok_anshost), and |
199 | * you just get the domain name in master file format. |
200 | * |
201 | * If no mailbox is supplied the returned string will be `.' in either |
abf5f52c |
202 | * case. |
e7afa27f |
203 | */ |
204 | |
5db99a2e |
205 | typedef enum { |
7aac35cd |
206 | adns_s_ok, |
207 | |
208 | /* locally induced errors */ |
209 | adns_s_nomemory, |
210 | adns_s_unknownrrtype, |
211 | adns_s_systemfail, |
212 | |
213 | adns_s_max_localfail= 29, |
214 | |
215 | /* remotely induced errors, detected locally */ |
216 | adns_s_timeout, |
217 | adns_s_allservfail, |
218 | adns_s_norecurse, |
219 | adns_s_invalidresponse, |
220 | adns_s_unknownformat, |
221 | |
222 | adns_s_max_remotefail= 59, |
223 | |
224 | /* remotely induced errors, reported by remote server to us */ |
225 | adns_s_rcodeservfail, |
226 | adns_s_rcodeformaterror, |
227 | adns_s_rcodenotimplemented, |
228 | adns_s_rcoderefused, |
229 | adns_s_rcodeunknown, |
230 | |
231 | adns_s_max_tempfail= 99, |
232 | |
233 | /* remote configuration errors */ |
234 | adns_s_inconsistent, /* PTR gives domain whose A does not exist and match */ |
235 | adns_s_prohibitedcname, /* CNAME, but eg A expected (not if _qf_loosecname) */ |
236 | adns_s_answerdomaininvalid, |
237 | adns_s_answerdomaintoolong, |
238 | adns_s_invaliddata, |
239 | |
240 | adns_s_max_misconfig= 199, |
241 | |
242 | /* permanent problems with the query */ |
243 | adns_s_querydomainwrong, |
244 | adns_s_querydomaininvalid, |
245 | adns_s_querydomaintoolong, |
246 | |
247 | adns_s_max_misquery= 299, |
248 | |
249 | /* permanent errors */ |
250 | adns_s_nxdomain, |
251 | adns_s_nodata, |
252 | |
253 | adns_s_max_permfail= 499 |
254 | |
5db99a2e |
255 | } adns_status; |
256 | |
5617a135 |
257 | typedef struct { |
cd363ffd |
258 | int len; |
259 | union { |
260 | struct sockaddr sa; |
261 | struct sockaddr_in inet; |
262 | } addr; |
bc01473e |
263 | } adns_rr_addr; |
cd363ffd |
264 | |
265 | typedef struct { |
26eb6bdc |
266 | char *host; |
6927715a |
267 | adns_status astatus; |
268 | int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */ |
bc01473e |
269 | adns_rr_addr *addrs; |
a1d2d0ed |
270 | } adns_rr_hostaddr; |
d05cc330 |
271 | |
272 | typedef struct { |
61093792 |
273 | char *(array[2]); |
d05cc330 |
274 | } adns_rr_strpair; |
275 | |
276 | typedef struct { |
277 | int i; |
26eb6bdc |
278 | adns_rr_hostaddr ha; |
a1d2d0ed |
279 | } adns_rr_inthostaddr; |
d05cc330 |
280 | |
281 | typedef struct { |
7aac35cd |
282 | /* Used both for mx_raw, in which case i is the preference and str |
283 | * the domain, and for txt, in which case each entry has i for the |
284 | * `text' length, and str for the data (which will have had an extra |
285 | * nul appended so that if it was plain text it is now a |
286 | * null-terminated string). |
f2ad23ee |
287 | */ |
d05cc330 |
288 | int i; |
289 | char *str; |
290 | } adns_rr_intstr; |
291 | |
292 | typedef struct { |
61093792 |
293 | adns_rr_intstr array[2]; |
294 | } adns_rr_intstrpair; |
295 | |
296 | typedef struct { |
297 | char *mname, *rname; |
d05cc330 |
298 | unsigned long serial, refresh, retry, expire, minimum; |
299 | } adns_rr_soa; |
6927715a |
300 | |
301 | typedef struct { |
5db99a2e |
302 | adns_status status; |
303 | char *cname; /* always NULL if query was for CNAME records */ |
7aac35cd |
304 | char *owner; /* only set if req'd in query flags; maybe 0 on error anyway */ |
1e9efa71 |
305 | adns_rrtype type; /* guaranteed to be same as in query */ |
7aac35cd |
306 | time_t expires;/*abs time. def only if _s_ok, nxdomain or nodata. NOT TTL!*/ |
0872e289 |
307 | int nrrs, rrsz; /* nrrs is 0 if an error occurs */ |
5db99a2e |
308 | union { |
965c9782 |
309 | void *untyped; |
310 | unsigned char *bytes; |
7aac35cd |
311 | char *(*str); /* ns_raw, cname, ptr, ptr_raw */ |
312 | adns_rr_intstr *(*manyistr); /* txt (list strs ends with i=-1, str=0)*/ |
313 | adns_rr_addr *addr; /* addr */ |
314 | struct in_addr *inaddr; /* a */ |
315 | adns_rr_hostaddr *hostaddr; /* ns */ |
316 | adns_rr_intstrpair *intstrpair; /* hinfo */ |
317 | adns_rr_strpair *strpair; /* rp, rp_raw */ |
318 | adns_rr_inthostaddr *inthostaddr;/* mx */ |
319 | adns_rr_intstr *intstr; /* mx_raw */ |
320 | adns_rr_soa *soa; /* soa, soa_raw */ |
5db99a2e |
321 | } rrs; |
5617a135 |
322 | } adns_answer; |
5db99a2e |
323 | |
324 | /* Memory management: |
325 | * adns_state and adns_query are actually pointers to malloc'd state; |
326 | * On submission questions are copied, including the owner domain; |
d05cc330 |
327 | * Answers are malloc'd as a single piece of memory; pointers in the |
328 | * answer struct point into further memory in the answer. |
5db99a2e |
329 | * query_io: |
330 | * Must always be non-null pointer; |
331 | * If *query_io is 0 to start with then any query may be returned; |
332 | * If *query_io is !0 adns_query then only that query may be returned. |
9be46d86 |
333 | * If the call is successful, *query_io, *answer_r, and *context_r |
334 | * will all be set. |
5db99a2e |
335 | * Errors: |
74c94831 |
336 | * Return values are 0 or an errno value. |
337 | * |
338 | * For _init, _init_strcfg, _submit and _synchronous, system errors |
339 | * (eg, failure to create sockets, malloc failure, etc.) return errno |
340 | * values. |
341 | * |
342 | * For _wait and _check failures are reported in the answer |
c6f9dc7b |
343 | * structure, and only 0, ESRCH or (for _check) EAGAIN is |
74c94831 |
344 | * returned: if no (appropriate) requests are done adns_check returns |
c6f9dc7b |
345 | * EAGAIN; if no (appropriate) requests are outstanding both |
74c94831 |
346 | * adns_query and adns_wait return ESRCH. |
347 | * |
348 | * Additionally, _wait can return EINTR if you set adns_if_eintr. |
349 | * |
350 | * All other errors (nameserver failure, timed out connections, &c) |
351 | * are returned in the status field of the answer. After a |
352 | * successful _wait or _check, if status is nonzero then nrrs will be |
353 | * 0, otherwise it will be >0. type will always be the type |
354 | * requested. |
5db99a2e |
355 | */ |
356 | |
edb95764 |
357 | int adns_init(adns_state *newstate_r, adns_initflags flags, |
d6b271ae |
358 | FILE *diagfile /*0=>stderr*/); |
359 | |
edb95764 |
360 | int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags, |
d6b271ae |
361 | FILE *diagfile /*0=>discard*/, const char *configtext); |
38fcb64a |
362 | |
363 | /* Configuration: |
364 | * adns_init reads /etc/resolv.conf, which is expected to be (broadly |
45efc92a |
365 | * speaking) in the format expected by libresolv, and then |
366 | * /etc/resolv-adns.conf if it exists. adns_init_strcfg is instead |
367 | * passed a string which is interpreted as if it were the contents of |
368 | * resolv.conf or resolv-adns.conf. In general, configuration which |
369 | * is set later overrides any that is set earlier. |
38fcb64a |
370 | * |
45efc92a |
371 | * Standard directives understood in resolv[-adns].conf: |
38fcb64a |
372 | * |
373 | * nameserver <address> |
374 | * Must be followed by the IP address of a nameserver. Several |
375 | * nameservers may be specified, and they will be tried in the order |
376 | * found. There is a compiled in limit, currently 5, on the number |
377 | * of nameservers. (libresolv supports only 3 nameservers.) |
378 | * |
379 | * search <domain> ... |
380 | * Specifies the search list for queries which specify |
381 | * adns_qf_search. This is a list of domains to append to the query |
382 | * domain. The query domain will be tried as-is either before all |
383 | * of these or after them, depending on the ndots option setting |
384 | * (see below). |
385 | * |
386 | * domain <domain> |
387 | * This is present only for backward compatibility with obsolete |
388 | * versions of libresolv. It should not be used, and is interpreted |
389 | * by adns as if it were `search' - note that this is subtly |
390 | * different to libresolv's interpretation of this directive. |
391 | * |
392 | * sortlist <addr>/<mask> ... |
393 | * Should be followed by a sequence of IP-address and netmask pairs, |
394 | * separated by spaces. They may be specified as |
395 | * eg. 172.30.206.0/24 or 172.30.206.0/255.255.255.0. Currently up |
396 | * to 15 pairs may be specified (but note that libresolv only |
397 | * supports up to 10). |
398 | * |
399 | * options |
400 | * Should followed by one or more options, separated by spaces. |
401 | * Each option consists of an option name, followed by optionally |
402 | * a colon and a value. Options are listed below. |
403 | * |
45efc92a |
404 | * Non-standard directives understood in resolv[-adns].conf: |
38fcb64a |
405 | * |
406 | * clearnameservers |
407 | * Clears the list of nameservers, so that further nameserver lines |
408 | * start again from the beginning. |
409 | * |
410 | * include <filename> |
411 | * The specified file will be read. |
412 | * |
45efc92a |
413 | * Additionally, adns will ignore lines in resolv[-adns].conf which |
414 | * start with a #. |
38fcb64a |
415 | * |
416 | * Standard options understood: |
417 | * |
418 | * debug |
419 | * Enables debugging output from the resolver, which will be written |
420 | * to stderr. |
421 | * |
422 | * ndots:<count> |
423 | * Affects whether queries with adns_qf_search will be tried first |
424 | * without adding domains from the searchlist, or whether the bare |
425 | * query domain will be tried last. Queries which contain at least |
426 | * <count> dots will be tried bare first. The default is 1. |
427 | * |
428 | * Non-standard options understood: |
429 | * |
430 | * adns_checkc:none |
431 | * adns_checkc:entex |
432 | * adns_checkc:freq |
433 | * Changes the consistency checking frequency; this overrides the |
434 | * setting of adns_if_check_entex, adns_if_check_freq, or neither, |
435 | * in the flags passed to adns_init. |
436 | * |
437 | * There are a number of environment variables which can modify the |
438 | * behaviour of adns. They take effect only if adns_init is used, and |
439 | * the caller of adns_init can disable them using adns_if_noenv. In |
440 | * each case there is both a FOO and an ADNS_FOO; the latter is |
441 | * interpreted later so that it can override the former. Unless |
442 | * otherwise stated, environment variables are interpreted after |
45efc92a |
443 | * resolv[-adns].conf are read, in the order they are listed here. |
38fcb64a |
444 | * |
445 | * RES_CONF, ADNS_RES_CONF |
446 | * A filename, whose contets are in the format of resolv.conf. |
447 | * |
448 | * RES_CONF_TEXT, ADNS_RES_CONF_TEXT |
449 | * A string in the format of resolv.conf. |
450 | * |
451 | * RES_OPTIONS, ADNS_RES_OPTIONS |
452 | * These are parsed as if they appeared in the `options' line of a |
453 | * resolv.conf. In addition to being parsed at this point in the |
454 | * sequence, they are also parsed at the very beginning before |
455 | * resolv.conf or any other environment variables are read, so that |
456 | * any debug option can affect the processing of the configuration. |
457 | * |
458 | * LOCALDOMAIN, ADNS_LOCALDOMAIN |
459 | * These are interpreted as if their contents appeared in a `search' |
460 | * line in resolv.conf. |
461 | */ |
5db99a2e |
462 | |
463 | int adns_synchronous(adns_state ads, |
464 | const char *owner, |
465 | adns_rrtype type, |
edb95764 |
466 | adns_queryflags flags, |
9ab4dfce |
467 | adns_answer **answer_r); |
5617a135 |
468 | |
469 | /* NB: if you set adns_if_noautosys then _submit and _check do not |
74c94831 |
470 | * make any system calls; you must use some of the asynch-io event |
471 | * processing functions to actually get things to happen. |
5617a135 |
472 | */ |
5db99a2e |
473 | |
474 | int adns_submit(adns_state ads, |
475 | const char *owner, |
476 | adns_rrtype type, |
edb95764 |
477 | adns_queryflags flags, |
5db99a2e |
478 | void *context, |
e7afa27f |
479 | adns_query *query_r); |
5db99a2e |
480 | |
bcf33879 |
481 | /* The owner should be quoted in master file format. */ |
482 | |
e7afa27f |
483 | int adns_check(adns_state ads, |
5db99a2e |
484 | adns_query *query_io, |
9ab4dfce |
485 | adns_answer **answer_r, |
486 | void **context_r); |
5db99a2e |
487 | |
488 | int adns_wait(adns_state ads, |
489 | adns_query *query_io, |
9ab4dfce |
490 | adns_answer **answer_r, |
491 | void **context_r); |
5db99a2e |
492 | |
ef20fccf |
493 | /* same as adns_wait but uses poll(2) internally */ |
494 | int adns_wait_poll(adns_state ads, |
495 | adns_query *query_io, |
496 | adns_answer **answer_r, |
497 | void **context_r); |
498 | |
11c8bf9b |
499 | void adns_cancel(adns_query query); |
5db99a2e |
500 | |
74c94831 |
501 | /* The adns_query you get back from _submit is valid (ie, can be |
502 | * legitimately passed into adns functions) until it is returned by |
503 | * adns_check or adns_wait, or passed to adns_cancel. After that it |
504 | * must not be used. You can rely on it not being reused until the |
505 | * first adns_submit or _transact call using the same adns_state after |
506 | * it became invalid, so you may compare it for equality with other |
507 | * query handles until you next call _query or _transact. |
125de2a9 |
508 | * |
509 | * _submit and _synchronous return ENOSYS if they don't understand the |
510 | * query type. |
74c94831 |
511 | */ |
512 | |
0872e289 |
513 | int adns_submit_reverse(adns_state ads, |
514 | const struct sockaddr *addr, |
515 | adns_rrtype type, |
edb95764 |
516 | adns_queryflags flags, |
0872e289 |
517 | void *context, |
518 | adns_query *query_r); |
5e6342f0 |
519 | /* type must be _r_ptr or _r_ptr_raw. _qf_search is ignored. |
520 | * addr->sa_family must be AF_INET or you get ENOSYS. |
521 | */ |
0872e289 |
522 | |
d2f6d877 |
523 | int adns_submit_reverse_any(adns_state ads, |
524 | const struct sockaddr *addr, |
525 | const char *rzone, |
526 | adns_rrtype type, |
527 | adns_queryflags flags, |
528 | void *context, |
529 | adns_query *query_r); |
530 | /* For RBL-style reverse `zone's; look up |
531 | * <reversed-address>.<zone> |
532 | * Any type is allowed. _qf_search is ignored. |
533 | * addr->sa_family must be AF_INET or you get ENOSYS. |
534 | */ |
535 | |
74c94831 |
536 | void adns_finish(adns_state ads); |
98db6da3 |
537 | /* You may call this even if you have queries outstanding; |
538 | * they will be cancelled. |
539 | */ |
5db99a2e |
540 | |
e7afa27f |
541 | |
23dca174 |
542 | void adns_forallqueries_begin(adns_state ads); |
8f2aa812 |
543 | adns_query adns_forallqueries_next(adns_state ads, void **context_r); |
74c94831 |
544 | /* Iterator functions, which you can use to loop over the outstanding |
23dca174 |
545 | * (submitted but not yet successfuly checked/waited) queries. |
74c94831 |
546 | * |
23dca174 |
547 | * You can only have one iteration going at once. You may call _begin |
548 | * at any time; after that, an iteration will be in progress. You may |
549 | * only call _next when an iteration is in progress - anything else |
550 | * may coredump. The iteration remains in progress until _next |
551 | * returns 0, indicating that all the queries have been walked over, |
552 | * or ANY other adns function is called with the same adns_state (or a |
553 | * query in the same adns_state). There is no need to explicitly |
554 | * finish an iteration. |
555 | * |
8f2aa812 |
556 | * context_r may be 0. *context_r may not be set when _next returns 0. |
e7afa27f |
557 | */ |
5db99a2e |
558 | |
2ac463bf |
559 | void adns_checkconsistency(adns_state ads, adns_query qu); |
1389dc72 |
560 | /* Checks the consistency of adns's internal data structures. |
561 | * If any error is found, the program will abort(). |
2ac463bf |
562 | * You may pass 0 for qu; if you pass non-null then additional checks |
563 | * are done to make sure that qu is a valid query. |
1389dc72 |
564 | */ |
565 | |
74c94831 |
566 | /* |
567 | * Example expected/legal calling sequence for submit/check/wait: |
5db99a2e |
568 | * adns_init |
569 | * adns_submit 1 |
570 | * adns_submit 2 |
571 | * adns_submit 3 |
572 | * adns_wait 1 |
c6f9dc7b |
573 | * adns_check 3 -> EAGAIN |
5db99a2e |
574 | * adns_wait 2 |
575 | * adns_wait 3 |
576 | * .... |
577 | * adns_finish |
74c94831 |
578 | */ |
579 | |
580 | /* |
581 | * Entrypoints for generic asynch io: |
582 | * (these entrypoints are not very useful except in combination with * |
583 | * some of the other I/O model calls which can tell you which fds to |
584 | * be interested in): |
585 | * |
586 | * Note that any adns call may cause adns to open and close fds, so |
587 | * you must call beforeselect or beforepoll again just before |
588 | * blocking, or you may not have an up-to-date list of it's fds. |
589 | */ |
590 | |
591 | int adns_processany(adns_state ads); |
592 | /* Gives adns flow-of-control for a bit. This will never block, and |
593 | * can be used with any threading/asynch-io model. If some error |
594 | * occurred which might cause an event loop to spin then the errno |
595 | * value is returned. |
596 | */ |
597 | |
598 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now); |
599 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now); |
600 | int adns_processexceptional(adns_state ads, int fd, const struct timeval *now); |
601 | /* Gives adns flow-of-control so that it can process incoming data |
602 | * from, or send outgoing data via, fd. Very like _processany. If it |
603 | * returns zero then fd will no longer be readable or writeable |
604 | * (unless of course more data has arrived since). adns will _only_ |
7a1ae5ac |
605 | * use that fd and only in the manner specified, regardless of whether |
74c94831 |
606 | * adns_if_noautosys was specified. |
607 | * |
608 | * adns_processexceptional should be called when select(2) reports an |
609 | * exceptional condition, or poll(2) reports POLLPRI. |
610 | * |
611 | * It is fine to call _processreabable or _processwriteable when the |
612 | * fd is not ready, or with an fd that doesn't belong to adns; it will |
613 | * then just return 0. |
614 | * |
615 | * If some error occurred which might prevent an event loop to spin |
616 | * then the errno value is returned. |
617 | */ |
618 | |
619 | void adns_processtimeouts(adns_state ads, const struct timeval *now); |
620 | /* Gives adns flow-of-control so that it can process any timeouts |
621 | * which might have happened. Very like _processreadable/writeable. |
622 | * |
623 | * now may be 0; if it isn't, *now must be the current time, recently |
624 | * obtained from gettimeofday. |
625 | */ |
626 | |
627 | void adns_firsttimeout(adns_state ads, |
628 | struct timeval **tv_mod, struct timeval *tv_buf, |
629 | struct timeval now); |
630 | /* Asks adns when it would first like the opportunity to time |
631 | * something out. now must be the current time, from gettimeofday. |
632 | * |
633 | * If tv_mod points to 0 then tv_buf must be non-null, and |
634 | * _firsttimeout will fill in *tv_buf with the time until the first |
635 | * timeout, and make *tv_mod point to tv_buf. If adns doesn't have |
636 | * anything that might need timing out it will leave *tv_mod as 0. |
637 | * |
638 | * If *tv_mod is not 0 then tv_buf is not used. adns will update |
639 | * *tv_mod if it has any earlier timeout, and leave it alone if it |
640 | * doesn't. |
641 | * |
642 | * This call will not actually do any I/O, or change the fds that adns |
643 | * is using. It always succeeds and never blocks. |
644 | */ |
645 | |
646 | void adns_globalsystemfailure(adns_state ads); |
647 | /* If serious problem(s) happen which globally affect your ability to |
648 | * interact properly with adns, or adns's ability to function |
649 | * properly, you or adns can call this function. |
650 | * |
651 | * All currently outstanding queries will be made to fail with |
652 | * adns_s_systemfail, and adns will close any stream sockets it has |
653 | * open. |
654 | * |
655 | * This is used by adns, for example, if gettimeofday() fails. |
656 | * Without this the program's event loop might start to spin ! |
657 | * |
658 | * This call will never block. |
659 | */ |
660 | |
661 | /* |
662 | * Entrypoints for select-loop based asynch io: |
663 | */ |
664 | |
665 | void adns_beforeselect(adns_state ads, int *maxfd, fd_set *readfds, |
666 | fd_set *writefds, fd_set *exceptfds, |
667 | struct timeval **tv_mod, struct timeval *tv_buf, |
668 | const struct timeval *now); |
669 | /* Find out file descriptors adns is interested in, and when it would |
670 | * like the opportunity to time something out. If you do not plan to |
671 | * block then tv_mod may be 0. Otherwise, tv_mod and tv_buf are as |
672 | * for adns_firsttimeout. readfds, writefds, exceptfds and maxfd_io may |
673 | * not be 0. |
674 | * |
da0e3c0a |
675 | * If now is not 0 then this will never actually do any I/O, or change |
676 | * the fds that adns is using or the timeouts it wants. In any case |
677 | * it won't block, and it will set the timeout to zero if a query |
678 | * finishes in _beforeselect. |
74c94831 |
679 | */ |
680 | |
681 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, |
682 | const fd_set *writefds, const fd_set *exceptfds, |
683 | const struct timeval *now); |
684 | /* Gives adns flow-of-control for a bit; intended for use after |
685 | * select. This is just a fancy way of calling adns_processreadable/ |
686 | * writeable/timeouts as appropriate, as if select had returned the |
687 | * data being passed. Always succeeds. |
688 | */ |
689 | |
690 | /* |
691 | * Example calling sequence: |
5db99a2e |
692 | * |
5617a135 |
693 | * adns_init _noautosys |
5db99a2e |
694 | * loop { |
74c94831 |
695 | * adns_beforeselect |
5db99a2e |
696 | * select |
74c94831 |
697 | * adns_afterselect |
5617a135 |
698 | * ... |
699 | * adns_submit / adns_check |
700 | * ... |
5db99a2e |
701 | * } |
702 | */ |
703 | |
74c94831 |
704 | /* |
705 | * Entrypoints for poll-loop based asynch io: |
706 | */ |
707 | |
708 | struct pollfd; |
709 | /* In case your system doesn't have it or you forgot to include |
710 | * <sys/poll.h>, to stop the following declarations from causing |
711 | * problems. If your system doesn't have poll then the following |
712 | * entrypoints will not be defined in libadns. Sorry ! |
713 | */ |
714 | |
7aac35cd |
715 | int adns_beforepoll(adns_state ads, struct pollfd *fds, |
716 | int *nfds_io, int *timeout_io, |
74c94831 |
717 | const struct timeval *now); |
718 | /* Finds out which fd's adns is interested in, and when it would like |
719 | * to be able to time things out. This is in a form suitable for use |
720 | * with poll(2). |
721 | * |
722 | * On entry, usually fds should point to at least *nfds_io structs. |
723 | * adns will fill up to that many structs will information for poll, |
724 | * and record in *nfds_io how many structs it filled. If it wants to |
725 | * listen for more structs then *nfds_io will be set to the number |
726 | * required and _beforepoll will return ERANGE. |
727 | * |
74c94831 |
728 | * You may call _beforepoll with fds==0 and *nfds_io 0, in which case |
729 | * adns will fill in the number of fds that it might be interested in |
4f973eb5 |
730 | * in *nfds_io, and always return either 0 (if it is not interested in |
731 | * any fds) or ERANGE (if it is). |
732 | * |
dd9cf93b |
733 | * NOTE that (unless now is 0) adns may acquire additional fds |
4f973eb5 |
734 | * from one call to the next, so you must put adns_beforepoll in a |
735 | * loop, rather than assuming that the second call (with the buffer |
736 | * size requested by the first) will not return ERANGE. |
74c94831 |
737 | * |
738 | * adns only ever sets POLLIN, POLLOUT and POLLPRI in its pollfd |
739 | * structs, and only ever looks at those bits. POLLPRI is required to |
4f973eb5 |
740 | * detect TCP Urgent Data (which should not be used by a DNS server) |
74c94831 |
741 | * so that adns can know that the TCP stream is now useless. |
742 | * |
743 | * In any case, *timeout_io should be a timeout value as for poll(2), |
744 | * which adns will modify downwards as required. If the caller does |
4f973eb5 |
745 | * not plan to block then *timeout_io should be 0 on entry, or |
746 | * alternatively, timeout_io may be 0. (Alternatively, the caller may |
747 | * use _beforeselect with timeout_io==0 to find out about file |
748 | * descriptors, and use _firsttimeout is used to find out when adns |
749 | * might want to time something out.) |
74c94831 |
750 | * |
751 | * adns_beforepoll will return 0 on success, and will not fail for any |
752 | * reason other than the fds buffer being too small (ERANGE). |
753 | * |
dd9cf93b |
754 | * This call will never actually do any I/O. If you supply the |
755 | * current time it will not change the fds that adns is using or the |
756 | * timeouts it wants. |
757 | * |
758 | * In any case this call won't block. |
74c94831 |
759 | */ |
760 | |
761 | #define ADNS_POLLFDS_RECOMMENDED 2 |
762 | /* If you allocate an fds buf with at least RECOMMENDED entries then |
763 | * you are unlikely to need to enlarge it. You are recommended to do |
764 | * so if it's convenient. However, you must be prepared for adns to |
765 | * require more space than this. |
766 | */ |
767 | |
768 | void adns_afterpoll(adns_state ads, const struct pollfd *fds, int nfds, |
769 | const struct timeval *now); |
770 | /* Gives adns flow-of-control for a bit; intended for use after |
771 | * poll(2). fds and nfds should be the results from poll(). pollfd |
772 | * structs mentioning fds not belonging to adns will be ignored. |
773 | */ |
774 | |
775 | |
1e9efa71 |
776 | adns_status adns_rr_info(adns_rrtype type, |
777 | const char **rrtname_r, const char **fmtname_r, |
778 | int *len_r, |
779 | const void *datap, char **data_r); |
0872e289 |
780 | /* |
0872e289 |
781 | * Get information about a query type, or convert reply data to a |
782 | * textual form. type must be specified, and the official name of the |
783 | * corresponding RR type will be returned in *rrtname_r, and |
784 | * information about the processing style in *fmtname_r. The length |
785 | * of the table entry in an answer for that type will be returned in |
786 | * in *len_r. Any or all of rrtname_r, fmtname_r and len_r may be 0. |
787 | * If fmtname_r is non-null then *fmtname_r may be null on return, |
788 | * indicating that no special processing is involved. |
789 | * |
790 | * data_r be must be non-null iff datap is. In this case *data_r will |
791 | * be set to point to a string pointing to a representation of the RR |
792 | * data in master file format. (The owner name, timeout, class and |
793 | * type will not be present - only the data part of the RR.) The |
794 | * memory will have been obtained from malloc() and must be freed by |
795 | * the caller. |
1e9efa71 |
796 | * |
797 | * Usually this routine will succeed. Possible errors include: |
798 | * adns_s_nomemory |
9b86645c |
799 | * adns_s_rrtypeunknown |
1e9efa71 |
800 | * adns_s_invaliddata (*datap contained garbage) |
801 | * If an error occurs then no memory has been allocated, |
802 | * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined. |
0872e289 |
803 | * |
804 | * There are some adns-invented data formats which are not official |
805 | * master file formats. These include: |
806 | * |
807 | * Mailboxes if __qtf_mail822: these are just included as-is. |
808 | * |
809 | * Addresses (adns_rr_addr): these may be of pretty much any type. |
810 | * The representation is in two parts: first, a word for the address |
811 | * family (ie, in AF_XXX, the XXX), and then one or more items for the |
812 | * address itself, depending on the format. For an IPv4 address the |
813 | * syntax is INET followed by the dotted quad (from inet_ntoa). |
814 | * Currently only IPv4 is supported. |
815 | * |
0fb18816 |
816 | * Text strings (as in adns_rr_txt) appear inside double quotes, and |
817 | * use \" and \\ to represent " and \, and \xHH to represent |
818 | * characters not in the range 32-126. |
819 | * |
0872e289 |
820 | * Hostname with addresses (adns_rr_hostaddr): this consists of the |
0fb18816 |
821 | * hostname, as usual, followed by the adns_status value, as an |
822 | * abbreviation, and then a descriptive string (encoded as if it were |
823 | * a piece of text), for the address lookup, followed by zero or more |
eaf858ea |
824 | * addresses enclosed in ( and ). If the result was a temporary |
0872e289 |
825 | * failure, then a single ? appears instead of the ( ). If the |
eaf858ea |
826 | * result was a permanent failure then an empty pair of parentheses |
0872e289 |
827 | * appears (which a space in between). For example, one of the NS |
0fb18816 |
828 | * records for greenend.org.uk comes out like |
829 | * ns.chiark.greenend.org.uk ok "OK" ( INET 195.224.76.132 ) |
0872e289 |
830 | * an MX referring to a nonexistent host might come out like: |
0fb18816 |
831 | * 50 sun2.nsfnet-relay.ac.uk nxdomain "No such domain" ( ) |
0872e289 |
832 | * and if nameserver information is not available you might get: |
0fb18816 |
833 | * dns2.spong.dyn.ml.org timeout "DNS query timed out" ? |
1e9efa71 |
834 | */ |
835 | |
7f702335 |
836 | const char *adns_strerror(adns_status st); |
c2875680 |
837 | const char *adns_errabbrev(adns_status st); |
9e50e3ac |
838 | const char *adns_errtypeabbrev(adns_status st); |
74c94831 |
839 | /* Like strerror but for adns_status values. adns_errabbrev returns |
840 | * the abbreviation of the error - eg, for adns_s_timeout it returns |
9e50e3ac |
841 | * "timeout". adns_errtypeabbrev returns the abbreviation of the |
842 | * error class: ie, for values up to adns_s_max_XXX it will return the |
843 | * string XXX. You MUST NOT call these functions with status values |
74c94831 |
844 | * not returned by the same adns library. |
845 | */ |
7f702335 |
846 | |
62049492 |
847 | #ifdef __cplusplus |
848 | } /* end of extern "C" */ |
849 | #endif |
5db99a2e |
850 | #endif |