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5bb95567 | 1 | /* |
f3efc943 | 2 | * adns.h |
5448fc9f | 3 | * - adns user-visible API |
f3efc943 | 4 | */ |
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> | |
1a9d7092 | 69 | #include <net/if.h> |
e7afa27f | 70 | |
368c83e4 | 71 | #ifdef __cplusplus |
72 | extern "C" { /* I really dislike this - iwj. */ | |
73 | #endif | |
74 | ||
5f8085b7 MW |
75 | /* Whether to support address families other than IPv4 in responses which use |
76 | * the `adns_rr_addr' structure. This is a source-compatibility issue: old | |
77 | * clients may not expect to find address families other than AF_INET in | |
78 | * their query results. There's a separate binary compatibility issue to do | |
79 | * with the size of the `adns_rr_addr' structure, but we'll assume you can | |
80 | * cope with that because you have this header file. Define | |
81 | * `ADNS_FEATURE_IPV4ONLY' if you only want to see AF_INET addresses, or | |
82 | * `ADNS_FEATURE_MANYAF' to allow multiple address families; the default is | |
83 | * currently to stick with AF_INET only, but this is likely to change in a | |
84 | * later release of ADNS. | |
85 | */ | |
86 | #if !defined(ADNS_FEATURE_IPV4ONLY) && !defined(ADNS_FEATURE_MANYAF) | |
87 | # define ADNS_FEATURE_IPV4ONLY | |
88 | #elif defined(ADNS_FEATURE_IPV4ONLY) && defined(ADNS_FEATURE_MANYAF) | |
89 | # error "Feature flags ADNS_FEATURE_IPV4ONLY and ..._MANYAF are incompatible" | |
90 | #endif | |
91 | ||
8c3aa944 | 92 | /* All struct in_addr anywhere in adns are in NETWORK byte order. */ |
93 | ||
e7afa27f | 94 | typedef struct adns__state *adns_state; |
95 | typedef struct adns__query *adns_query; | |
5db99a2e | 96 | |
7a1f00f7 | 97 | typedef enum { /* In general, or together the desired flags: */ |
98 | adns_if_none= 0x0000,/* no flags. nicer than 0 for some compilers */ | |
7aac35cd | 99 | adns_if_noenv= 0x0001,/* do not look at environment */ |
100 | adns_if_noerrprint= 0x0002,/* never print to stderr (_debug overrides) */ | |
101 | adns_if_noserverwarn=0x0004,/* do not warn to stderr about duff servers etc */ | |
102 | adns_if_debug= 0x0008,/* enable all output to stderr plus debug msgs */ | |
103 | adns_if_logpid= 0x0080,/* include pid in diagnostic output */ | |
104 | adns_if_noautosys= 0x0010,/* do not make syscalls at every opportunity */ | |
105 | adns_if_eintr= 0x0020,/* allow _wait and _synchronous to return EINTR */ | |
106 | adns_if_nosigpipe= 0x0040,/* applic has SIGPIPE ignored, do not protect */ | |
107 | adns_if_checkc_entex=0x0100,/* consistency checks on entry/exit to adns fns */ | |
20078efc MW |
108 | adns_if_checkc_freq= 0x0300,/* consistency checks very frequently (slow!) */ |
109 | ||
110 | adns_if_af_v4only= 0x0400,/* only return IPv4 addresses, given the choice */ | |
111 | adns_if_af_v6only= 0x0800,/* only return IPv6 addresses, ... */ | |
112 | adns_if_afmask= adns_if_af_v4only|adns_if_af_v6only | |
113 | /* Only set one of these. They are policy flags, and overridden by the | |
114 | * adns_af:... options in resolv.conf. If the adns_qf_ipv... query | |
115 | * flags are incompatible with these settings (in the sense that no | |
116 | * address families are permitted at all) then the query flags take | |
117 | * precedence; otherwise only records which satisfy all of the stated | |
118 | * requirements are allowed. | |
119 | */ | |
5db99a2e | 120 | } adns_initflags; |
121 | ||
7a1f00f7 | 122 | typedef enum { /* In general, or together the desired flags: */ |
123 | adns_qf_none= 0x00000000,/* no flags */ | |
7aac35cd | 124 | adns_qf_search= 0x00000001,/* use the searchlist */ |
125 | adns_qf_usevc= 0x00000002,/* use a virtual circuit (TCP conn) */ | |
126 | adns_qf_owner= 0x00000004,/* fill in the owner field in the answer */ | |
127 | adns_qf_quoteok_query= 0x00000010,/* allow special chars in query domain */ | |
128 | adns_qf_quoteok_cname= 0x00000000,/* ... in CNAME we go via (now default) */ | |
129 | adns_qf_quoteok_anshost=0x00000040,/* ... in things supposedly hostnames */ | |
130 | adns_qf_quotefail_cname=0x00000080,/* refuse if quote-req chars in CNAME we go via */ | |
131 | adns_qf_cname_loose= 0x00000100,/* allow refs to CNAMEs - without, get _s_cname */ | |
132 | adns_qf_cname_forbid= 0x00000200,/* don't follow CNAMEs, instead give _s_cname */ | |
5f8085b7 | 133 | adns_qf_ipv4_only= 0x00000400,/* only ever return IPv4 addresses */ |
bcfd6f13 MW |
134 | adns_qf_ipv6_only= 0x00000800,/* ... and don't bother looking for IPv4 */ |
135 | adns_qf_ipv6_ok= 0x00000c00,/* returning IPv6 addresses is acceptable */ | |
136 | adns_qf_domapv4= 0x00001000,/* ... any IPv4 addresses should be v6-mapped */ | |
137 | adns_qf_ipv6_mapv4= adns_qf_ipv6_ok|adns_qf_domapv4, | |
138 | adns__qf_afmask= 0x00001c00,/* all the above flag bits */ | |
1a36f664 IJ |
139 | adns_qf_addrlit_scope_forbid=0x00002000,/* forbid %<scope> in IPv6 literals */ |
140 | adns_qf_addrlit_scope_numeric=0x00004000,/* %<scope> may only be numeric */ | |
7aac35cd | 141 | adns__qf_internalmask= 0x0ff00000 |
5db99a2e | 142 | } adns_queryflags; |
143 | ||
144 | typedef enum { | |
7d0aaee4 | 145 | adns_rrt_typemask= 0x0ffff, |
5f8085b7 MW |
146 | adns_rrt_reprmask= 0xffffff, |
147 | adns__qtf_deref_bit=0x10000,/* internal version of ..._deref below */ | |
3db6be73 | 148 | adns__qtf_mail822= 0x20000,/* return mailboxes in RFC822 rcpt field fmt */ |
ba2dbede | 149 | |
150 | adns_r_unknown= 0x40000, | |
151 | /* To use this, ask for records of type <rr-type-code>|adns_r_unknown. | |
7d0aaee4 | 152 | * adns will not process the RDATA - you'll get adns_rr_byteblocks, |
153 | * where the int is the length and the unsigned char* points to the | |
154 | * data. String representation of the RR data (by adns_rrinfo) is as in | |
155 | * RFC3597. adns_rr_info will not return the type name in *rrtname_r | |
156 | * (due to memory management problems); *fmtname_r will be set to | |
157 | * "unknown". | |
ba2dbede | 158 | * |
159 | * Do not specify adns_r_unknown along with a known RR type which | |
7d0aaee4 | 160 | * requires domain name uncompression (see RFC3597 s4); domain names |
161 | * will not be uncompressed and the resulting data would be useless. | |
162 | * Asking for meta-RR types via adns_r_unknown will not work properly | |
163 | * either and may make adns complain about server misbehaviour, so don't | |
164 | * do that. | |
165 | * | |
166 | * Don't forget adns_qf_quoteok if that's what you want. */ | |
167 | ||
5f8085b7 MW |
168 | adns__qtf_bigaddr=0x1000000,/* use the new larger sockaddr union */ |
169 | adns__qtf_manyaf= 0x2000000,/* permitted to return multiple address families */ | |
170 | ||
171 | adns__qtf_deref= adns__qtf_deref_bit|adns__qtf_bigaddr | |
172 | #ifdef ADNS_FEATURE_MANYAF | |
173 | |adns__qtf_manyaf | |
174 | #endif | |
175 | ,/* dereference domains; perhaps get extra data */ | |
176 | ||
7aac35cd | 177 | adns_r_none= 0, |
178 | ||
179 | adns_r_a= 1, | |
180 | ||
181 | adns_r_ns_raw= 2, | |
182 | adns_r_ns= adns_r_ns_raw|adns__qtf_deref, | |
183 | ||
184 | adns_r_cname= 5, | |
185 | ||
186 | adns_r_soa_raw= 6, | |
187 | adns_r_soa= adns_r_soa_raw|adns__qtf_mail822, | |
188 | ||
4f6dbe69 | 189 | adns_r_ptr_raw= 12, /* do not mind PTR with wrong or missing A */ |
7aac35cd | 190 | adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref, |
191 | ||
192 | adns_r_hinfo= 13, | |
193 | ||
194 | adns_r_mx_raw= 15, | |
195 | adns_r_mx= adns_r_mx_raw|adns__qtf_deref, | |
196 | ||
197 | adns_r_txt= 16, | |
198 | ||
199 | adns_r_rp_raw= 17, | |
200 | adns_r_rp= adns_r_rp_raw|adns__qtf_mail822, | |
3db6be73 | 201 | |
9136cf0c MW |
202 | adns_r_aaaa= 28, |
203 | ||
3db6be73 | 204 | /* For SRV records, query domain without _qf_quoteok_query must look |
205 | * as expected from SRV RFC with hostname-like Name. _With_ | |
206 | * _quoteok_query, any query domain is allowed. */ | |
207 | adns_r_srv_raw= 33, | |
208 | adns_r_srv= adns_r_srv_raw|adns__qtf_deref, | |
7aac35cd | 209 | |
210 | adns_r_addr= adns_r_a|adns__qtf_deref | |
211 | ||
5db99a2e | 212 | } adns_rrtype; |
213 | ||
0872e289 | 214 | /* |
215 | * In queries without qf_quoteok_*, all domains must have standard | |
216 | * legal syntax, or you get adns_s_querydomainvalid (if the query | |
217 | * domain contains bad characters) or adns_s_answerdomaininvalid (if | |
218 | * the answer contains bad characters). | |
219 | * | |
220 | * In queries _with_ qf_quoteok_*, domains in the query or response | |
221 | * may contain any characters, quoted according to RFC1035 5.1. On | |
222 | * input to adns, the char* is a pointer to the interior of a " | |
996e3b68 | 223 | * delimited string, except that " may appear in it unquoted. On |
224 | * output, the char* is a pointer to a string which would be legal | |
225 | * either inside or outside " delimiters; any character which isn't | |
226 | * legal in a hostname (ie alphanumeric or hyphen) or one of _ / + | |
227 | * (the three other punctuation characters commonly abused in domain | |
228 | * names) will be quoted, as \X if it is a printing ASCII character or | |
229 | * \DDD otherwise. | |
230 | * | |
0872e289 | 231 | * If the query goes via a CNAME then the canonical name (ie, the |
232 | * thing that the CNAME record refers to) is usually allowed to | |
233 | * contain any characters, which will be quoted as above. With | |
234 | * adns_qf_quotefail_cname you get adns_s_answerdomaininvalid when | |
235 | * this happens. (This is a change from version 0.4 and earlier, in | |
236 | * which failing the query was the default, and you had to say | |
237 | * adns_qf_quoteok_cname to avoid this; that flag is now deprecated.) | |
238 | * | |
239 | * In version 0.4 and earlier, asking for _raw records containing | |
240 | * mailboxes without specifying _qf_quoteok_anshost was silly. This | |
241 | * is no longer the case. In this version only parts of responses | |
242 | * that are actually supposed to be hostnames will be refused by | |
243 | * default if quote-requiring characters are found. | |
244 | */ | |
245 | ||
246 | /* | |
247 | * If you ask for an RR which contains domains which are actually | |
248 | * encoded mailboxes, and don't ask for the _raw version, then adns | |
249 | * returns the mailbox formatted suitably for an RFC822 recipient | |
250 | * header field. The particular format used is that if the mailbox | |
251 | * requires quoting according to the rules in RFC822 then the | |
252 | * local-part is quoted in double quotes, which end at the next | |
67ca39c8 | 253 | * unescaped double quote (\ is the escape char, and is doubled, and |
254 | * is used to escape only \ and "). If the local-part is legal | |
255 | * without quoting according to RFC822, it is presented as-is. In any | |
256 | * case the local-part is followed by an @ and the domain. The domain | |
257 | * will not contain any characters not legal in hostnames. | |
258 | * | |
259 | * Unquoted local-parts may contain any printing 7-bit ASCII | |
260 | * except the punctuation characters ( ) < > @ , ; : \ " [ ] | |
261 | * I.e. they may contain alphanumerics, and the following | |
262 | * punctuation characters: ! # % ^ & * - _ = + { } . | |
263 | * | |
264 | * adns will reject local parts containing control characters (byte | |
265 | * values 0-31, 127-159, and 255) - these appear to be legal according | |
abf5f52c | 266 | * to RFC822 (at least 0-127) but are clearly a bad idea. RFC1035 |
267 | * syntax does not make any distinction between a single RFC822 | |
268 | * quoted-string containing full stops, and a series of quoted-strings | |
269 | * separated by full stops; adns will return anything that isn't all | |
270 | * valid atoms as a single quoted-string. RFC822 does not allow | |
271 | * high-bit-set characters at all, but adns does allow them in | |
272 | * local-parts, treating them as needing quoting. | |
0872e289 | 273 | * |
274 | * If you ask for the domain with _raw then _no_ checking is done | |
275 | * (even on the host part, regardless of adns_qf_quoteok_anshost), and | |
276 | * you just get the domain name in master file format. | |
277 | * | |
278 | * If no mailbox is supplied the returned string will be `.' in either | |
abf5f52c | 279 | * case. |
e7afa27f | 280 | */ |
281 | ||
5db99a2e | 282 | typedef enum { |
7aac35cd | 283 | adns_s_ok, |
284 | ||
285 | /* locally induced errors */ | |
286 | adns_s_nomemory, | |
287 | adns_s_unknownrrtype, | |
288 | adns_s_systemfail, | |
289 | ||
290 | adns_s_max_localfail= 29, | |
291 | ||
292 | /* remotely induced errors, detected locally */ | |
293 | adns_s_timeout, | |
294 | adns_s_allservfail, | |
295 | adns_s_norecurse, | |
296 | adns_s_invalidresponse, | |
297 | adns_s_unknownformat, | |
298 | ||
299 | adns_s_max_remotefail= 59, | |
300 | ||
301 | /* remotely induced errors, reported by remote server to us */ | |
302 | adns_s_rcodeservfail, | |
303 | adns_s_rcodeformaterror, | |
304 | adns_s_rcodenotimplemented, | |
305 | adns_s_rcoderefused, | |
306 | adns_s_rcodeunknown, | |
307 | ||
308 | adns_s_max_tempfail= 99, | |
309 | ||
310 | /* remote configuration errors */ | |
311 | adns_s_inconsistent, /* PTR gives domain whose A does not exist and match */ | |
312 | adns_s_prohibitedcname, /* CNAME, but eg A expected (not if _qf_loosecname) */ | |
313 | adns_s_answerdomaininvalid, | |
314 | adns_s_answerdomaintoolong, | |
315 | adns_s_invaliddata, | |
316 | ||
317 | adns_s_max_misconfig= 199, | |
318 | ||
319 | /* permanent problems with the query */ | |
320 | adns_s_querydomainwrong, | |
321 | adns_s_querydomaininvalid, | |
322 | adns_s_querydomaintoolong, | |
323 | ||
324 | adns_s_max_misquery= 299, | |
325 | ||
326 | /* permanent errors */ | |
327 | adns_s_nxdomain, | |
328 | adns_s_nodata, | |
329 | ||
330 | adns_s_max_permfail= 499 | |
331 | ||
5db99a2e | 332 | } adns_status; |
333 | ||
5f8085b7 MW |
334 | typedef union { |
335 | struct sockaddr sa; | |
336 | struct sockaddr_in inet; | |
337 | } adns_sockaddr_v4only; | |
338 | ||
339 | typedef union { | |
340 | struct sockaddr sa; | |
341 | struct sockaddr_in inet; | |
342 | struct sockaddr_in6 inet6; | |
343 | char adns__padding[240]; /* Good idea? I'm inclined to think not. */ | |
344 | } adns_sockaddr; | |
345 | ||
5617a135 | 346 | typedef struct { |
cd363ffd | 347 | int len; |
5f8085b7 | 348 | adns_sockaddr addr; |
bc01473e | 349 | } adns_rr_addr; |
cd363ffd | 350 | |
351 | typedef struct { | |
5f8085b7 MW |
352 | int len; |
353 | adns_sockaddr_v4only addr; | |
354 | } adns_rr_addr_v4only; | |
355 | ||
356 | typedef struct { | |
26eb6bdc | 357 | char *host; |
6927715a | 358 | adns_status astatus; |
359 | int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */ | |
bc01473e | 360 | adns_rr_addr *addrs; |
a1d2d0ed | 361 | } adns_rr_hostaddr; |
d05cc330 | 362 | |
363 | typedef struct { | |
61093792 | 364 | char *(array[2]); |
d05cc330 | 365 | } adns_rr_strpair; |
366 | ||
367 | typedef struct { | |
368 | int i; | |
26eb6bdc | 369 | adns_rr_hostaddr ha; |
a1d2d0ed | 370 | } adns_rr_inthostaddr; |
d05cc330 | 371 | |
372 | typedef struct { | |
7aac35cd | 373 | /* Used both for mx_raw, in which case i is the preference and str |
374 | * the domain, and for txt, in which case each entry has i for the | |
375 | * `text' length, and str for the data (which will have had an extra | |
376 | * nul appended so that if it was plain text it is now a | |
377 | * null-terminated string). | |
f2ad23ee | 378 | */ |
d05cc330 | 379 | int i; |
380 | char *str; | |
381 | } adns_rr_intstr; | |
382 | ||
383 | typedef struct { | |
61093792 | 384 | adns_rr_intstr array[2]; |
385 | } adns_rr_intstrpair; | |
386 | ||
387 | typedef struct { | |
388 | char *mname, *rname; | |
d05cc330 | 389 | unsigned long serial, refresh, retry, expire, minimum; |
390 | } adns_rr_soa; | |
6927715a | 391 | |
392 | typedef struct { | |
3db6be73 | 393 | int priority, weight, port; |
394 | char *host; | |
395 | } adns_rr_srvraw; | |
396 | ||
397 | typedef struct { | |
398 | int priority, weight, port; | |
399 | adns_rr_hostaddr ha; | |
2248cdf4 | 400 | } adns_rr_srvha; |
3db6be73 | 401 | |
402 | typedef struct { | |
7d0aaee4 | 403 | int len; |
404 | unsigned char *data; | |
405 | } adns_rr_byteblock; | |
406 | ||
407 | typedef struct { | |
5db99a2e | 408 | adns_status status; |
409 | char *cname; /* always NULL if query was for CNAME records */ | |
7aac35cd | 410 | char *owner; /* only set if req'd in query flags; maybe 0 on error anyway */ |
1e9efa71 | 411 | adns_rrtype type; /* guaranteed to be same as in query */ |
7aac35cd | 412 | time_t expires;/*abs time. def only if _s_ok, nxdomain or nodata. NOT TTL!*/ |
0872e289 | 413 | int nrrs, rrsz; /* nrrs is 0 if an error occurs */ |
5db99a2e | 414 | union { |
965c9782 | 415 | void *untyped; |
416 | unsigned char *bytes; | |
7aac35cd | 417 | char *(*str); /* ns_raw, cname, ptr, ptr_raw */ |
418 | adns_rr_intstr *(*manyistr); /* txt (list strs ends with i=-1, str=0)*/ | |
419 | adns_rr_addr *addr; /* addr */ | |
420 | struct in_addr *inaddr; /* a */ | |
9136cf0c | 421 | struct in6_addr *in6addr; /* aaaa */ |
7aac35cd | 422 | adns_rr_hostaddr *hostaddr; /* ns */ |
423 | adns_rr_intstrpair *intstrpair; /* hinfo */ | |
424 | adns_rr_strpair *strpair; /* rp, rp_raw */ | |
425 | adns_rr_inthostaddr *inthostaddr;/* mx */ | |
7d0aaee4 | 426 | adns_rr_intstr *intstr; /* mx_raw */ |
7aac35cd | 427 | adns_rr_soa *soa; /* soa, soa_raw */ |
3db6be73 | 428 | adns_rr_srvraw *srvraw; /* srv_raw */ |
2248cdf4 | 429 | adns_rr_srvha *srvha;/* srv */ |
7d0aaee4 | 430 | adns_rr_byteblock *byteblock; /* ...|unknown */ |
5db99a2e | 431 | } rrs; |
5617a135 | 432 | } adns_answer; |
5db99a2e | 433 | |
434 | /* Memory management: | |
435 | * adns_state and adns_query are actually pointers to malloc'd state; | |
436 | * On submission questions are copied, including the owner domain; | |
d05cc330 | 437 | * Answers are malloc'd as a single piece of memory; pointers in the |
438 | * answer struct point into further memory in the answer. | |
5db99a2e | 439 | * query_io: |
440 | * Must always be non-null pointer; | |
441 | * If *query_io is 0 to start with then any query may be returned; | |
442 | * If *query_io is !0 adns_query then only that query may be returned. | |
9be46d86 | 443 | * If the call is successful, *query_io, *answer_r, and *context_r |
444 | * will all be set. | |
5db99a2e | 445 | * Errors: |
74c94831 | 446 | * Return values are 0 or an errno value. |
447 | * | |
448 | * For _init, _init_strcfg, _submit and _synchronous, system errors | |
449 | * (eg, failure to create sockets, malloc failure, etc.) return errno | |
032b6358 | 450 | * values. EINVAL from _init et al means the configuration file |
451 | * is erroneous and cannot be parsed. | |
74c94831 | 452 | * |
453 | * For _wait and _check failures are reported in the answer | |
c6f9dc7b | 454 | * structure, and only 0, ESRCH or (for _check) EAGAIN is |
74c94831 | 455 | * returned: if no (appropriate) requests are done adns_check returns |
c6f9dc7b | 456 | * EAGAIN; if no (appropriate) requests are outstanding both |
74c94831 | 457 | * adns_query and adns_wait return ESRCH. |
458 | * | |
459 | * Additionally, _wait can return EINTR if you set adns_if_eintr. | |
460 | * | |
461 | * All other errors (nameserver failure, timed out connections, &c) | |
462 | * are returned in the status field of the answer. After a | |
463 | * successful _wait or _check, if status is nonzero then nrrs will be | |
464 | * 0, otherwise it will be >0. type will always be the type | |
465 | * requested. | |
5db99a2e | 466 | */ |
467 | ||
5448fc9f | 468 | /* Threads: |
469 | * adns does not use any static modifiable state, so it | |
470 | * is safe to call adns_init several times and then use the | |
471 | * resulting adns_states concurrently. | |
472 | * However, it is NOT safe to make simultaneous calls into | |
473 | * adns using the same adns_state; a single adns_state must be used | |
474 | * only by one thread at a time. You can solve this problem by | |
475 | * having one adns_state per thread, or if that isn't feasible, you | |
476 | * could maintain a pool of adns_states. Unfortunately neither of | |
477 | * these approaches has optimal performance. | |
478 | */ | |
479 | ||
edb95764 | 480 | int adns_init(adns_state *newstate_r, adns_initflags flags, |
d6b271ae | 481 | FILE *diagfile /*0=>stderr*/); |
482 | ||
edb95764 | 483 | int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags, |
d6b271ae | 484 | FILE *diagfile /*0=>discard*/, const char *configtext); |
38fcb64a | 485 | |
86ea5e62 | 486 | typedef void adns_logcallbackfn(adns_state ads, void *logfndata, |
487 | const char *fmt, va_list al); | |
488 | /* Will be called perhaps several times for each message; when the | |
489 | * message is complete, the string implied by fmt and al will end in | |
490 | * a newline. Log messages start with `adns debug:' or `adns | |
491 | * warning:' or `adns:' (for errors), or `adns debug [PID]:' | |
492 | * etc. if adns_if_logpid is set. */ | |
493 | ||
494 | int adns_init_logfn(adns_state *newstate_r, adns_initflags flags, | |
495 | const char *configtext /*0=>use default config files*/, | |
496 | adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */, | |
497 | void *logfndata /*0 with logfn==0 => discard*/); | |
498 | ||
38fcb64a | 499 | /* Configuration: |
500 | * adns_init reads /etc/resolv.conf, which is expected to be (broadly | |
45efc92a | 501 | * speaking) in the format expected by libresolv, and then |
502 | * /etc/resolv-adns.conf if it exists. adns_init_strcfg is instead | |
503 | * passed a string which is interpreted as if it were the contents of | |
504 | * resolv.conf or resolv-adns.conf. In general, configuration which | |
505 | * is set later overrides any that is set earlier. | |
38fcb64a | 506 | * |
45efc92a | 507 | * Standard directives understood in resolv[-adns].conf: |
38fcb64a | 508 | * |
509 | * nameserver <address> | |
510 | * Must be followed by the IP address of a nameserver. Several | |
511 | * nameservers may be specified, and they will be tried in the order | |
512 | * found. There is a compiled in limit, currently 5, on the number | |
513 | * of nameservers. (libresolv supports only 3 nameservers.) | |
514 | * | |
515 | * search <domain> ... | |
516 | * Specifies the search list for queries which specify | |
517 | * adns_qf_search. This is a list of domains to append to the query | |
518 | * domain. The query domain will be tried as-is either before all | |
519 | * of these or after them, depending on the ndots option setting | |
520 | * (see below). | |
521 | * | |
522 | * domain <domain> | |
523 | * This is present only for backward compatibility with obsolete | |
524 | * versions of libresolv. It should not be used, and is interpreted | |
525 | * by adns as if it were `search' - note that this is subtly | |
526 | * different to libresolv's interpretation of this directive. | |
527 | * | |
528 | * sortlist <addr>/<mask> ... | |
529 | * Should be followed by a sequence of IP-address and netmask pairs, | |
530 | * separated by spaces. They may be specified as | |
531 | * eg. 172.30.206.0/24 or 172.30.206.0/255.255.255.0. Currently up | |
532 | * to 15 pairs may be specified (but note that libresolv only | |
533 | * supports up to 10). | |
534 | * | |
535 | * options | |
536 | * Should followed by one or more options, separated by spaces. | |
537 | * Each option consists of an option name, followed by optionally | |
538 | * a colon and a value. Options are listed below. | |
539 | * | |
45efc92a | 540 | * Non-standard directives understood in resolv[-adns].conf: |
38fcb64a | 541 | * |
542 | * clearnameservers | |
543 | * Clears the list of nameservers, so that further nameserver lines | |
544 | * start again from the beginning. | |
545 | * | |
546 | * include <filename> | |
547 | * The specified file will be read. | |
548 | * | |
45efc92a | 549 | * Additionally, adns will ignore lines in resolv[-adns].conf which |
550 | * start with a #. | |
38fcb64a | 551 | * |
552 | * Standard options understood: | |
553 | * | |
554 | * debug | |
555 | * Enables debugging output from the resolver, which will be written | |
556 | * to stderr. | |
557 | * | |
558 | * ndots:<count> | |
559 | * Affects whether queries with adns_qf_search will be tried first | |
560 | * without adding domains from the searchlist, or whether the bare | |
561 | * query domain will be tried last. Queries which contain at least | |
562 | * <count> dots will be tried bare first. The default is 1. | |
563 | * | |
564 | * Non-standard options understood: | |
565 | * | |
566 | * adns_checkc:none | |
567 | * adns_checkc:entex | |
568 | * adns_checkc:freq | |
569 | * Changes the consistency checking frequency; this overrides the | |
570 | * setting of adns_if_check_entex, adns_if_check_freq, or neither, | |
571 | * in the flags passed to adns_init. | |
20078efc MW |
572 | * |
573 | * adns_af:v4only | |
574 | * adns_af:v6only | |
575 | * adns_af:any | |
576 | * Controls whether ADNS looks for IPv4 (A records) and IPv6 (AAAA | |
577 | * records) addresses when it's trying to build a socket address. | |
578 | * The default is `any' which means to allow both. The `sortlist' | |
579 | * directive can be used to control the relative preference of IPv4 | |
580 | * and IPv6 addresses if both are returned for the same query. | |
581 | * These override the corresponding init flags (covered by | |
582 | * adns_if_afmask). | |
38fcb64a | 583 | * |
584 | * There are a number of environment variables which can modify the | |
585 | * behaviour of adns. They take effect only if adns_init is used, and | |
586 | * the caller of adns_init can disable them using adns_if_noenv. In | |
587 | * each case there is both a FOO and an ADNS_FOO; the latter is | |
588 | * interpreted later so that it can override the former. Unless | |
589 | * otherwise stated, environment variables are interpreted after | |
45efc92a | 590 | * resolv[-adns].conf are read, in the order they are listed here. |
38fcb64a | 591 | * |
592 | * RES_CONF, ADNS_RES_CONF | |
593 | * A filename, whose contets are in the format of resolv.conf. | |
594 | * | |
595 | * RES_CONF_TEXT, ADNS_RES_CONF_TEXT | |
596 | * A string in the format of resolv.conf. | |
597 | * | |
598 | * RES_OPTIONS, ADNS_RES_OPTIONS | |
599 | * These are parsed as if they appeared in the `options' line of a | |
600 | * resolv.conf. In addition to being parsed at this point in the | |
601 | * sequence, they are also parsed at the very beginning before | |
602 | * resolv.conf or any other environment variables are read, so that | |
603 | * any debug option can affect the processing of the configuration. | |
604 | * | |
605 | * LOCALDOMAIN, ADNS_LOCALDOMAIN | |
606 | * These are interpreted as if their contents appeared in a `search' | |
607 | * line in resolv.conf. | |
608 | */ | |
5db99a2e | 609 | |
610 | int adns_synchronous(adns_state ads, | |
611 | const char *owner, | |
612 | adns_rrtype type, | |
edb95764 | 613 | adns_queryflags flags, |
9ab4dfce | 614 | adns_answer **answer_r); |
5617a135 | 615 | |
616 | /* NB: if you set adns_if_noautosys then _submit and _check do not | |
74c94831 | 617 | * make any system calls; you must use some of the asynch-io event |
618 | * processing functions to actually get things to happen. | |
5617a135 | 619 | */ |
5db99a2e | 620 | |
621 | int adns_submit(adns_state ads, | |
622 | const char *owner, | |
623 | adns_rrtype type, | |
edb95764 | 624 | adns_queryflags flags, |
5db99a2e | 625 | void *context, |
e7afa27f | 626 | adns_query *query_r); |
5db99a2e | 627 | |
bcf33879 | 628 | /* The owner should be quoted in master file format. */ |
629 | ||
e7afa27f | 630 | int adns_check(adns_state ads, |
5db99a2e | 631 | adns_query *query_io, |
9ab4dfce | 632 | adns_answer **answer_r, |
633 | void **context_r); | |
5db99a2e | 634 | |
635 | int adns_wait(adns_state ads, | |
636 | adns_query *query_io, | |
9ab4dfce | 637 | adns_answer **answer_r, |
638 | void **context_r); | |
5db99a2e | 639 | |
ef20fccf | 640 | /* same as adns_wait but uses poll(2) internally */ |
641 | int adns_wait_poll(adns_state ads, | |
642 | adns_query *query_io, | |
643 | adns_answer **answer_r, | |
644 | void **context_r); | |
645 | ||
11c8bf9b | 646 | void adns_cancel(adns_query query); |
5db99a2e | 647 | |
74c94831 | 648 | /* The adns_query you get back from _submit is valid (ie, can be |
649 | * legitimately passed into adns functions) until it is returned by | |
650 | * adns_check or adns_wait, or passed to adns_cancel. After that it | |
651 | * must not be used. You can rely on it not being reused until the | |
652 | * first adns_submit or _transact call using the same adns_state after | |
653 | * it became invalid, so you may compare it for equality with other | |
654 | * query handles until you next call _query or _transact. | |
125de2a9 | 655 | * |
656 | * _submit and _synchronous return ENOSYS if they don't understand the | |
657 | * query type. | |
74c94831 | 658 | */ |
659 | ||
0872e289 | 660 | int adns_submit_reverse(adns_state ads, |
661 | const struct sockaddr *addr, | |
662 | adns_rrtype type, | |
edb95764 | 663 | adns_queryflags flags, |
0872e289 | 664 | void *context, |
665 | adns_query *query_r); | |
5e6342f0 | 666 | /* type must be _r_ptr or _r_ptr_raw. _qf_search is ignored. |
667 | * addr->sa_family must be AF_INET or you get ENOSYS. | |
668 | */ | |
0872e289 | 669 | |
d2f6d877 | 670 | int adns_submit_reverse_any(adns_state ads, |
671 | const struct sockaddr *addr, | |
672 | const char *rzone, | |
673 | adns_rrtype type, | |
674 | adns_queryflags flags, | |
675 | void *context, | |
676 | adns_query *query_r); | |
677 | /* For RBL-style reverse `zone's; look up | |
678 | * <reversed-address>.<zone> | |
679 | * Any type is allowed. _qf_search is ignored. | |
680 | * addr->sa_family must be AF_INET or you get ENOSYS. | |
681 | */ | |
682 | ||
74c94831 | 683 | void adns_finish(adns_state ads); |
98db6da3 | 684 | /* You may call this even if you have queries outstanding; |
685 | * they will be cancelled. | |
686 | */ | |
5db99a2e | 687 | |
1a9d7092 IJ |
688 | #define ADNS_ADDR2TEXT_BUFLEN \ |
689 | (INET6_ADDRSTRLEN + 1/*%*/ \ | |
690 | + ((IF_NAMESIZE-1) > 9 ? (IF_NAMESIZE-1) : 9/*uint32*/) \ | |
691 | + 1/* nul; included in IF_NAMESIZE */) | |
504877d1 | 692 | |
1a36f664 IJ |
693 | int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags, |
694 | struct sockaddr *sa, | |
b0f1ed64 | 695 | socklen_t *salen /* set if OK or ENOSPC; otherwise undef */); |
1a36f664 IJ |
696 | int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags, |
697 | char *buffer, int *buflen /* set iff ENOSPC */, | |
b0f1ed64 | 698 | int *port_r /* may be 0 */); |
1a36f664 | 699 | /* |
504877d1 IJ |
700 | * port is always in host byte order and is simply copied to and |
701 | * from the appropriate sockaddr field (byteswapped as necessary). | |
1a36f664 IJ |
702 | * |
703 | * The only flags supported are adns_qf_addrlit_...; others are | |
704 | * ignored. | |
705 | * | |
706 | * Error return values are: | |
707 | * | |
708 | * ENOSPC Output buffer is too small. Can only happen if | |
709 | * *buflen < ADNS_ADDR2TEXT_BUFLEN or | |
710 | * *salen < sizeof(adns_sockaddr). On return, | |
711 | * *buflen or *salen has been updated by adns. | |
712 | * | |
713 | * EINVAL text has invalid syntax. | |
714 | * | |
715 | * text represents an address family not supported by | |
716 | * this version of adns. | |
717 | * | |
718 | * Scoped address supplied (text contained "%" or | |
719 | * sin6_scope_id nonzero) but caller specified | |
720 | * adns_qf_addrlit_scope_forbid. | |
721 | * | |
722 | * Scope name supplied in text but caller specified | |
723 | * adns_qf_addrlit_scope_numeric. | |
724 | * | |
725 | * EAFNOSUPPORT sa->sa_family is not supported (addr2text only). | |
726 | * | |
727 | * Only if neither adns_qf_addrlit_scope_forbid nor | |
728 | * adns_qf_addrlit_scope_numeric are set: | |
729 | * | |
730 | * ENOSYS Scope name supplied in text but IPv6 address part of | |
731 | * sockaddr is not a link local address. | |
732 | * | |
733 | * ENXIO Scope name supplied in text but if_nametoindex | |
734 | * said it wasn't a valid local interface name. | |
735 | * | |
736 | * EIO Scoped address supplied but if_nametoindex failed | |
737 | * in an unexpected way; adns has printed a message to | |
738 | * stderr. | |
739 | * | |
740 | * any other if_nametoindex failed in a more-or-less expected way. | |
504877d1 | 741 | */ |
e7afa27f | 742 | |
23dca174 | 743 | void adns_forallqueries_begin(adns_state ads); |
8f2aa812 | 744 | adns_query adns_forallqueries_next(adns_state ads, void **context_r); |
74c94831 | 745 | /* Iterator functions, which you can use to loop over the outstanding |
23dca174 | 746 | * (submitted but not yet successfuly checked/waited) queries. |
74c94831 | 747 | * |
23dca174 | 748 | * You can only have one iteration going at once. You may call _begin |
749 | * at any time; after that, an iteration will be in progress. You may | |
750 | * only call _next when an iteration is in progress - anything else | |
751 | * may coredump. The iteration remains in progress until _next | |
752 | * returns 0, indicating that all the queries have been walked over, | |
753 | * or ANY other adns function is called with the same adns_state (or a | |
754 | * query in the same adns_state). There is no need to explicitly | |
755 | * finish an iteration. | |
756 | * | |
8f2aa812 | 757 | * context_r may be 0. *context_r may not be set when _next returns 0. |
e7afa27f | 758 | */ |
5db99a2e | 759 | |
2ac463bf | 760 | void adns_checkconsistency(adns_state ads, adns_query qu); |
1389dc72 | 761 | /* Checks the consistency of adns's internal data structures. |
762 | * If any error is found, the program will abort(). | |
2ac463bf | 763 | * You may pass 0 for qu; if you pass non-null then additional checks |
764 | * are done to make sure that qu is a valid query. | |
1389dc72 | 765 | */ |
766 | ||
74c94831 | 767 | /* |
768 | * Example expected/legal calling sequence for submit/check/wait: | |
5db99a2e | 769 | * adns_init |
770 | * adns_submit 1 | |
771 | * adns_submit 2 | |
772 | * adns_submit 3 | |
773 | * adns_wait 1 | |
c6f9dc7b | 774 | * adns_check 3 -> EAGAIN |
5db99a2e | 775 | * adns_wait 2 |
776 | * adns_wait 3 | |
777 | * .... | |
778 | * adns_finish | |
74c94831 | 779 | */ |
780 | ||
781 | /* | |
782 | * Entrypoints for generic asynch io: | |
783 | * (these entrypoints are not very useful except in combination with * | |
784 | * some of the other I/O model calls which can tell you which fds to | |
785 | * be interested in): | |
786 | * | |
787 | * Note that any adns call may cause adns to open and close fds, so | |
788 | * you must call beforeselect or beforepoll again just before | |
789 | * blocking, or you may not have an up-to-date list of it's fds. | |
790 | */ | |
791 | ||
792 | int adns_processany(adns_state ads); | |
793 | /* Gives adns flow-of-control for a bit. This will never block, and | |
794 | * can be used with any threading/asynch-io model. If some error | |
795 | * occurred which might cause an event loop to spin then the errno | |
796 | * value is returned. | |
797 | */ | |
798 | ||
799 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now); | |
800 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now); | |
801 | int adns_processexceptional(adns_state ads, int fd, const struct timeval *now); | |
802 | /* Gives adns flow-of-control so that it can process incoming data | |
803 | * from, or send outgoing data via, fd. Very like _processany. If it | |
804 | * returns zero then fd will no longer be readable or writeable | |
805 | * (unless of course more data has arrived since). adns will _only_ | |
7a1ae5ac | 806 | * use that fd and only in the manner specified, regardless of whether |
74c94831 | 807 | * adns_if_noautosys was specified. |
808 | * | |
809 | * adns_processexceptional should be called when select(2) reports an | |
810 | * exceptional condition, or poll(2) reports POLLPRI. | |
811 | * | |
812 | * It is fine to call _processreabable or _processwriteable when the | |
813 | * fd is not ready, or with an fd that doesn't belong to adns; it will | |
814 | * then just return 0. | |
815 | * | |
816 | * If some error occurred which might prevent an event loop to spin | |
817 | * then the errno value is returned. | |
818 | */ | |
819 | ||
820 | void adns_processtimeouts(adns_state ads, const struct timeval *now); | |
821 | /* Gives adns flow-of-control so that it can process any timeouts | |
822 | * which might have happened. Very like _processreadable/writeable. | |
823 | * | |
824 | * now may be 0; if it isn't, *now must be the current time, recently | |
825 | * obtained from gettimeofday. | |
826 | */ | |
827 | ||
828 | void adns_firsttimeout(adns_state ads, | |
829 | struct timeval **tv_mod, struct timeval *tv_buf, | |
830 | struct timeval now); | |
831 | /* Asks adns when it would first like the opportunity to time | |
832 | * something out. now must be the current time, from gettimeofday. | |
833 | * | |
834 | * If tv_mod points to 0 then tv_buf must be non-null, and | |
835 | * _firsttimeout will fill in *tv_buf with the time until the first | |
836 | * timeout, and make *tv_mod point to tv_buf. If adns doesn't have | |
837 | * anything that might need timing out it will leave *tv_mod as 0. | |
838 | * | |
839 | * If *tv_mod is not 0 then tv_buf is not used. adns will update | |
840 | * *tv_mod if it has any earlier timeout, and leave it alone if it | |
841 | * doesn't. | |
842 | * | |
843 | * This call will not actually do any I/O, or change the fds that adns | |
844 | * is using. It always succeeds and never blocks. | |
845 | */ | |
846 | ||
847 | void adns_globalsystemfailure(adns_state ads); | |
848 | /* If serious problem(s) happen which globally affect your ability to | |
849 | * interact properly with adns, or adns's ability to function | |
850 | * properly, you or adns can call this function. | |
851 | * | |
852 | * All currently outstanding queries will be made to fail with | |
853 | * adns_s_systemfail, and adns will close any stream sockets it has | |
854 | * open. | |
855 | * | |
856 | * This is used by adns, for example, if gettimeofday() fails. | |
857 | * Without this the program's event loop might start to spin ! | |
858 | * | |
859 | * This call will never block. | |
860 | */ | |
861 | ||
862 | /* | |
863 | * Entrypoints for select-loop based asynch io: | |
864 | */ | |
865 | ||
866 | void adns_beforeselect(adns_state ads, int *maxfd, fd_set *readfds, | |
867 | fd_set *writefds, fd_set *exceptfds, | |
868 | struct timeval **tv_mod, struct timeval *tv_buf, | |
869 | const struct timeval *now); | |
870 | /* Find out file descriptors adns is interested in, and when it would | |
871 | * like the opportunity to time something out. If you do not plan to | |
872 | * block then tv_mod may be 0. Otherwise, tv_mod and tv_buf are as | |
873 | * for adns_firsttimeout. readfds, writefds, exceptfds and maxfd_io may | |
874 | * not be 0. | |
875 | * | |
86ea5e62 | 876 | * If tv_mod is 0 on entry then this will never actually do any I/O, |
877 | * or change the fds that adns is using or the timeouts it wants. In | |
878 | * any case it won't block, and it will set the timeout to zero if a | |
879 | * query finishes in _beforeselect. | |
74c94831 | 880 | */ |
881 | ||
882 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, | |
883 | const fd_set *writefds, const fd_set *exceptfds, | |
884 | const struct timeval *now); | |
885 | /* Gives adns flow-of-control for a bit; intended for use after | |
886 | * select. This is just a fancy way of calling adns_processreadable/ | |
887 | * writeable/timeouts as appropriate, as if select had returned the | |
888 | * data being passed. Always succeeds. | |
889 | */ | |
890 | ||
891 | /* | |
892 | * Example calling sequence: | |
5db99a2e | 893 | * |
5617a135 | 894 | * adns_init _noautosys |
5db99a2e | 895 | * loop { |
74c94831 | 896 | * adns_beforeselect |
5db99a2e | 897 | * select |
74c94831 | 898 | * adns_afterselect |
5617a135 | 899 | * ... |
900 | * adns_submit / adns_check | |
901 | * ... | |
5db99a2e | 902 | * } |
903 | */ | |
904 | ||
74c94831 | 905 | /* |
906 | * Entrypoints for poll-loop based asynch io: | |
907 | */ | |
908 | ||
909 | struct pollfd; | |
910 | /* In case your system doesn't have it or you forgot to include | |
911 | * <sys/poll.h>, to stop the following declarations from causing | |
912 | * problems. If your system doesn't have poll then the following | |
913 | * entrypoints will not be defined in libadns. Sorry ! | |
914 | */ | |
915 | ||
7aac35cd | 916 | int adns_beforepoll(adns_state ads, struct pollfd *fds, |
917 | int *nfds_io, int *timeout_io, | |
74c94831 | 918 | const struct timeval *now); |
919 | /* Finds out which fd's adns is interested in, and when it would like | |
920 | * to be able to time things out. This is in a form suitable for use | |
921 | * with poll(2). | |
922 | * | |
923 | * On entry, usually fds should point to at least *nfds_io structs. | |
924 | * adns will fill up to that many structs will information for poll, | |
925 | * and record in *nfds_io how many structs it filled. If it wants to | |
926 | * listen for more structs then *nfds_io will be set to the number | |
927 | * required and _beforepoll will return ERANGE. | |
928 | * | |
74c94831 | 929 | * You may call _beforepoll with fds==0 and *nfds_io 0, in which case |
930 | * adns will fill in the number of fds that it might be interested in | |
4f973eb5 | 931 | * in *nfds_io, and always return either 0 (if it is not interested in |
932 | * any fds) or ERANGE (if it is). | |
933 | * | |
dd9cf93b | 934 | * NOTE that (unless now is 0) adns may acquire additional fds |
4f973eb5 | 935 | * from one call to the next, so you must put adns_beforepoll in a |
936 | * loop, rather than assuming that the second call (with the buffer | |
937 | * size requested by the first) will not return ERANGE. | |
74c94831 | 938 | * |
939 | * adns only ever sets POLLIN, POLLOUT and POLLPRI in its pollfd | |
940 | * structs, and only ever looks at those bits. POLLPRI is required to | |
4f973eb5 | 941 | * detect TCP Urgent Data (which should not be used by a DNS server) |
74c94831 | 942 | * so that adns can know that the TCP stream is now useless. |
943 | * | |
944 | * In any case, *timeout_io should be a timeout value as for poll(2), | |
945 | * which adns will modify downwards as required. If the caller does | |
4f973eb5 | 946 | * not plan to block then *timeout_io should be 0 on entry, or |
947 | * alternatively, timeout_io may be 0. (Alternatively, the caller may | |
948 | * use _beforeselect with timeout_io==0 to find out about file | |
949 | * descriptors, and use _firsttimeout is used to find out when adns | |
950 | * might want to time something out.) | |
74c94831 | 951 | * |
952 | * adns_beforepoll will return 0 on success, and will not fail for any | |
953 | * reason other than the fds buffer being too small (ERANGE). | |
954 | * | |
dd9cf93b | 955 | * This call will never actually do any I/O. If you supply the |
956 | * current time it will not change the fds that adns is using or the | |
957 | * timeouts it wants. | |
958 | * | |
959 | * In any case this call won't block. | |
74c94831 | 960 | */ |
961 | ||
705b9b15 | 962 | #define ADNS_POLLFDS_RECOMMENDED 3 |
74c94831 | 963 | /* If you allocate an fds buf with at least RECOMMENDED entries then |
964 | * you are unlikely to need to enlarge it. You are recommended to do | |
965 | * so if it's convenient. However, you must be prepared for adns to | |
966 | * require more space than this. | |
967 | */ | |
968 | ||
969 | void adns_afterpoll(adns_state ads, const struct pollfd *fds, int nfds, | |
970 | const struct timeval *now); | |
971 | /* Gives adns flow-of-control for a bit; intended for use after | |
972 | * poll(2). fds and nfds should be the results from poll(). pollfd | |
973 | * structs mentioning fds not belonging to adns will be ignored. | |
974 | */ | |
975 | ||
976 | ||
1e9efa71 | 977 | adns_status adns_rr_info(adns_rrtype type, |
978 | const char **rrtname_r, const char **fmtname_r, | |
979 | int *len_r, | |
980 | const void *datap, char **data_r); | |
0872e289 | 981 | /* |
0872e289 | 982 | * Get information about a query type, or convert reply data to a |
983 | * textual form. type must be specified, and the official name of the | |
984 | * corresponding RR type will be returned in *rrtname_r, and | |
985 | * information about the processing style in *fmtname_r. The length | |
986 | * of the table entry in an answer for that type will be returned in | |
987 | * in *len_r. Any or all of rrtname_r, fmtname_r and len_r may be 0. | |
988 | * If fmtname_r is non-null then *fmtname_r may be null on return, | |
989 | * indicating that no special processing is involved. | |
990 | * | |
991 | * data_r be must be non-null iff datap is. In this case *data_r will | |
992 | * be set to point to a string pointing to a representation of the RR | |
993 | * data in master file format. (The owner name, timeout, class and | |
994 | * type will not be present - only the data part of the RR.) The | |
995 | * memory will have been obtained from malloc() and must be freed by | |
996 | * the caller. | |
1e9efa71 | 997 | * |
998 | * Usually this routine will succeed. Possible errors include: | |
999 | * adns_s_nomemory | |
9b86645c | 1000 | * adns_s_rrtypeunknown |
1e9efa71 | 1001 | * adns_s_invaliddata (*datap contained garbage) |
1002 | * If an error occurs then no memory has been allocated, | |
1003 | * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined. | |
0872e289 | 1004 | * |
1005 | * There are some adns-invented data formats which are not official | |
1006 | * master file formats. These include: | |
1007 | * | |
1008 | * Mailboxes if __qtf_mail822: these are just included as-is. | |
1009 | * | |
1010 | * Addresses (adns_rr_addr): these may be of pretty much any type. | |
1011 | * The representation is in two parts: first, a word for the address | |
1012 | * family (ie, in AF_XXX, the XXX), and then one or more items for the | |
1013 | * address itself, depending on the format. For an IPv4 address the | |
1014 | * syntax is INET followed by the dotted quad (from inet_ntoa). | |
1015 | * Currently only IPv4 is supported. | |
1016 | * | |
0fb18816 | 1017 | * Text strings (as in adns_rr_txt) appear inside double quotes, and |
1018 | * use \" and \\ to represent " and \, and \xHH to represent | |
1019 | * characters not in the range 32-126. | |
1020 | * | |
0872e289 | 1021 | * Hostname with addresses (adns_rr_hostaddr): this consists of the |
0fb18816 | 1022 | * hostname, as usual, followed by the adns_status value, as an |
1023 | * abbreviation, and then a descriptive string (encoded as if it were | |
1024 | * a piece of text), for the address lookup, followed by zero or more | |
eaf858ea | 1025 | * addresses enclosed in ( and ). If the result was a temporary |
0872e289 | 1026 | * failure, then a single ? appears instead of the ( ). If the |
eaf858ea | 1027 | * result was a permanent failure then an empty pair of parentheses |
0872e289 | 1028 | * appears (which a space in between). For example, one of the NS |
0fb18816 | 1029 | * records for greenend.org.uk comes out like |
1030 | * ns.chiark.greenend.org.uk ok "OK" ( INET 195.224.76.132 ) | |
0872e289 | 1031 | * an MX referring to a nonexistent host might come out like: |
0fb18816 | 1032 | * 50 sun2.nsfnet-relay.ac.uk nxdomain "No such domain" ( ) |
0872e289 | 1033 | * and if nameserver information is not available you might get: |
0fb18816 | 1034 | * dns2.spong.dyn.ml.org timeout "DNS query timed out" ? |
1e9efa71 | 1035 | */ |
1036 | ||
7f702335 | 1037 | const char *adns_strerror(adns_status st); |
c2875680 | 1038 | const char *adns_errabbrev(adns_status st); |
9e50e3ac | 1039 | const char *adns_errtypeabbrev(adns_status st); |
74c94831 | 1040 | /* Like strerror but for adns_status values. adns_errabbrev returns |
1041 | * the abbreviation of the error - eg, for adns_s_timeout it returns | |
9e50e3ac | 1042 | * "timeout". adns_errtypeabbrev returns the abbreviation of the |
1043 | * error class: ie, for values up to adns_s_max_XXX it will return the | |
1044 | * string XXX. You MUST NOT call these functions with status values | |
74c94831 | 1045 | * not returned by the same adns library. |
1046 | */ | |
7f702335 | 1047 | |
62049492 | 1048 | #ifdef __cplusplus |
1049 | } /* end of extern "C" */ | |
1050 | #endif | |
5db99a2e | 1051 | #endif |