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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 */ | |
b4e502bf | 141 | adns_qf_addrlit_ipv4_quadonly=0x00008000,/* reject non-dotted-quad ipv4 */ |
7aac35cd | 142 | adns__qf_internalmask= 0x0ff00000 |
5db99a2e | 143 | } adns_queryflags; |
144 | ||
145 | typedef enum { | |
7d0aaee4 | 146 | adns_rrt_typemask= 0x0ffff, |
5f8085b7 MW |
147 | adns_rrt_reprmask= 0xffffff, |
148 | adns__qtf_deref_bit=0x10000,/* internal version of ..._deref below */ | |
3db6be73 | 149 | adns__qtf_mail822= 0x20000,/* return mailboxes in RFC822 rcpt field fmt */ |
ba2dbede | 150 | |
151 | adns_r_unknown= 0x40000, | |
152 | /* To use this, ask for records of type <rr-type-code>|adns_r_unknown. | |
7d0aaee4 | 153 | * adns will not process the RDATA - you'll get adns_rr_byteblocks, |
154 | * where the int is the length and the unsigned char* points to the | |
155 | * data. String representation of the RR data (by adns_rrinfo) is as in | |
156 | * RFC3597. adns_rr_info will not return the type name in *rrtname_r | |
157 | * (due to memory management problems); *fmtname_r will be set to | |
158 | * "unknown". | |
ba2dbede | 159 | * |
160 | * Do not specify adns_r_unknown along with a known RR type which | |
7d0aaee4 | 161 | * requires domain name uncompression (see RFC3597 s4); domain names |
162 | * will not be uncompressed and the resulting data would be useless. | |
163 | * Asking for meta-RR types via adns_r_unknown will not work properly | |
164 | * either and may make adns complain about server misbehaviour, so don't | |
165 | * do that. | |
166 | * | |
167 | * Don't forget adns_qf_quoteok if that's what you want. */ | |
168 | ||
5f8085b7 MW |
169 | adns__qtf_bigaddr=0x1000000,/* use the new larger sockaddr union */ |
170 | adns__qtf_manyaf= 0x2000000,/* permitted to return multiple address families */ | |
171 | ||
172 | adns__qtf_deref= adns__qtf_deref_bit|adns__qtf_bigaddr | |
173 | #ifdef ADNS_FEATURE_MANYAF | |
174 | |adns__qtf_manyaf | |
175 | #endif | |
176 | ,/* dereference domains; perhaps get extra data */ | |
177 | ||
7aac35cd | 178 | adns_r_none= 0, |
179 | ||
180 | adns_r_a= 1, | |
181 | ||
182 | adns_r_ns_raw= 2, | |
183 | adns_r_ns= adns_r_ns_raw|adns__qtf_deref, | |
184 | ||
185 | adns_r_cname= 5, | |
186 | ||
187 | adns_r_soa_raw= 6, | |
188 | adns_r_soa= adns_r_soa_raw|adns__qtf_mail822, | |
189 | ||
4f6dbe69 | 190 | adns_r_ptr_raw= 12, /* do not mind PTR with wrong or missing A */ |
7aac35cd | 191 | adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref, |
192 | ||
193 | adns_r_hinfo= 13, | |
194 | ||
195 | adns_r_mx_raw= 15, | |
196 | adns_r_mx= adns_r_mx_raw|adns__qtf_deref, | |
197 | ||
198 | adns_r_txt= 16, | |
199 | ||
200 | adns_r_rp_raw= 17, | |
201 | adns_r_rp= adns_r_rp_raw|adns__qtf_mail822, | |
3db6be73 | 202 | |
9136cf0c MW |
203 | adns_r_aaaa= 28, |
204 | ||
3db6be73 | 205 | /* For SRV records, query domain without _qf_quoteok_query must look |
206 | * as expected from SRV RFC with hostname-like Name. _With_ | |
207 | * _quoteok_query, any query domain is allowed. */ | |
208 | adns_r_srv_raw= 33, | |
209 | adns_r_srv= adns_r_srv_raw|adns__qtf_deref, | |
7aac35cd | 210 | |
211 | adns_r_addr= adns_r_a|adns__qtf_deref | |
212 | ||
5db99a2e | 213 | } adns_rrtype; |
214 | ||
0872e289 | 215 | /* |
216 | * In queries without qf_quoteok_*, all domains must have standard | |
217 | * legal syntax, or you get adns_s_querydomainvalid (if the query | |
218 | * domain contains bad characters) or adns_s_answerdomaininvalid (if | |
219 | * the answer contains bad characters). | |
220 | * | |
221 | * In queries _with_ qf_quoteok_*, domains in the query or response | |
222 | * may contain any characters, quoted according to RFC1035 5.1. On | |
223 | * input to adns, the char* is a pointer to the interior of a " | |
996e3b68 | 224 | * delimited string, except that " may appear in it unquoted. On |
225 | * output, the char* is a pointer to a string which would be legal | |
226 | * either inside or outside " delimiters; any character which isn't | |
227 | * legal in a hostname (ie alphanumeric or hyphen) or one of _ / + | |
228 | * (the three other punctuation characters commonly abused in domain | |
229 | * names) will be quoted, as \X if it is a printing ASCII character or | |
230 | * \DDD otherwise. | |
231 | * | |
0872e289 | 232 | * If the query goes via a CNAME then the canonical name (ie, the |
233 | * thing that the CNAME record refers to) is usually allowed to | |
234 | * contain any characters, which will be quoted as above. With | |
235 | * adns_qf_quotefail_cname you get adns_s_answerdomaininvalid when | |
236 | * this happens. (This is a change from version 0.4 and earlier, in | |
237 | * which failing the query was the default, and you had to say | |
238 | * adns_qf_quoteok_cname to avoid this; that flag is now deprecated.) | |
239 | * | |
240 | * In version 0.4 and earlier, asking for _raw records containing | |
241 | * mailboxes without specifying _qf_quoteok_anshost was silly. This | |
242 | * is no longer the case. In this version only parts of responses | |
243 | * that are actually supposed to be hostnames will be refused by | |
244 | * default if quote-requiring characters are found. | |
245 | */ | |
246 | ||
247 | /* | |
248 | * If you ask for an RR which contains domains which are actually | |
249 | * encoded mailboxes, and don't ask for the _raw version, then adns | |
250 | * returns the mailbox formatted suitably for an RFC822 recipient | |
251 | * header field. The particular format used is that if the mailbox | |
252 | * requires quoting according to the rules in RFC822 then the | |
253 | * local-part is quoted in double quotes, which end at the next | |
67ca39c8 | 254 | * unescaped double quote (\ is the escape char, and is doubled, and |
255 | * is used to escape only \ and "). If the local-part is legal | |
256 | * without quoting according to RFC822, it is presented as-is. In any | |
257 | * case the local-part is followed by an @ and the domain. The domain | |
258 | * will not contain any characters not legal in hostnames. | |
259 | * | |
260 | * Unquoted local-parts may contain any printing 7-bit ASCII | |
261 | * except the punctuation characters ( ) < > @ , ; : \ " [ ] | |
262 | * I.e. they may contain alphanumerics, and the following | |
263 | * punctuation characters: ! # % ^ & * - _ = + { } . | |
264 | * | |
265 | * adns will reject local parts containing control characters (byte | |
266 | * values 0-31, 127-159, and 255) - these appear to be legal according | |
abf5f52c | 267 | * to RFC822 (at least 0-127) but are clearly a bad idea. RFC1035 |
268 | * syntax does not make any distinction between a single RFC822 | |
269 | * quoted-string containing full stops, and a series of quoted-strings | |
270 | * separated by full stops; adns will return anything that isn't all | |
271 | * valid atoms as a single quoted-string. RFC822 does not allow | |
272 | * high-bit-set characters at all, but adns does allow them in | |
273 | * local-parts, treating them as needing quoting. | |
0872e289 | 274 | * |
275 | * If you ask for the domain with _raw then _no_ checking is done | |
276 | * (even on the host part, regardless of adns_qf_quoteok_anshost), and | |
277 | * you just get the domain name in master file format. | |
278 | * | |
279 | * If no mailbox is supplied the returned string will be `.' in either | |
abf5f52c | 280 | * case. |
e7afa27f | 281 | */ |
282 | ||
5db99a2e | 283 | typedef enum { |
7aac35cd | 284 | adns_s_ok, |
285 | ||
286 | /* locally induced errors */ | |
287 | adns_s_nomemory, | |
288 | adns_s_unknownrrtype, | |
289 | adns_s_systemfail, | |
290 | ||
291 | adns_s_max_localfail= 29, | |
292 | ||
293 | /* remotely induced errors, detected locally */ | |
294 | adns_s_timeout, | |
295 | adns_s_allservfail, | |
296 | adns_s_norecurse, | |
297 | adns_s_invalidresponse, | |
298 | adns_s_unknownformat, | |
299 | ||
300 | adns_s_max_remotefail= 59, | |
301 | ||
302 | /* remotely induced errors, reported by remote server to us */ | |
303 | adns_s_rcodeservfail, | |
304 | adns_s_rcodeformaterror, | |
305 | adns_s_rcodenotimplemented, | |
306 | adns_s_rcoderefused, | |
307 | adns_s_rcodeunknown, | |
308 | ||
309 | adns_s_max_tempfail= 99, | |
310 | ||
311 | /* remote configuration errors */ | |
312 | adns_s_inconsistent, /* PTR gives domain whose A does not exist and match */ | |
313 | adns_s_prohibitedcname, /* CNAME, but eg A expected (not if _qf_loosecname) */ | |
314 | adns_s_answerdomaininvalid, | |
315 | adns_s_answerdomaintoolong, | |
316 | adns_s_invaliddata, | |
317 | ||
318 | adns_s_max_misconfig= 199, | |
319 | ||
320 | /* permanent problems with the query */ | |
321 | adns_s_querydomainwrong, | |
322 | adns_s_querydomaininvalid, | |
323 | adns_s_querydomaintoolong, | |
324 | ||
325 | adns_s_max_misquery= 299, | |
326 | ||
327 | /* permanent errors */ | |
328 | adns_s_nxdomain, | |
329 | adns_s_nodata, | |
330 | ||
331 | adns_s_max_permfail= 499 | |
332 | ||
5db99a2e | 333 | } adns_status; |
334 | ||
5f8085b7 MW |
335 | typedef union { |
336 | struct sockaddr sa; | |
337 | struct sockaddr_in inet; | |
338 | } adns_sockaddr_v4only; | |
339 | ||
340 | typedef union { | |
341 | struct sockaddr sa; | |
342 | struct sockaddr_in inet; | |
343 | struct sockaddr_in6 inet6; | |
344 | char adns__padding[240]; /* Good idea? I'm inclined to think not. */ | |
345 | } adns_sockaddr; | |
346 | ||
5617a135 | 347 | typedef struct { |
cd363ffd | 348 | int len; |
5f8085b7 | 349 | adns_sockaddr addr; |
bc01473e | 350 | } adns_rr_addr; |
cd363ffd | 351 | |
352 | typedef struct { | |
5f8085b7 MW |
353 | int len; |
354 | adns_sockaddr_v4only addr; | |
355 | } adns_rr_addr_v4only; | |
356 | ||
357 | typedef struct { | |
26eb6bdc | 358 | char *host; |
6927715a | 359 | adns_status astatus; |
360 | int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */ | |
bc01473e | 361 | adns_rr_addr *addrs; |
a1d2d0ed | 362 | } adns_rr_hostaddr; |
d05cc330 | 363 | |
364 | typedef struct { | |
61093792 | 365 | char *(array[2]); |
d05cc330 | 366 | } adns_rr_strpair; |
367 | ||
368 | typedef struct { | |
369 | int i; | |
26eb6bdc | 370 | adns_rr_hostaddr ha; |
a1d2d0ed | 371 | } adns_rr_inthostaddr; |
d05cc330 | 372 | |
373 | typedef struct { | |
7aac35cd | 374 | /* Used both for mx_raw, in which case i is the preference and str |
375 | * the domain, and for txt, in which case each entry has i for the | |
376 | * `text' length, and str for the data (which will have had an extra | |
377 | * nul appended so that if it was plain text it is now a | |
378 | * null-terminated string). | |
f2ad23ee | 379 | */ |
d05cc330 | 380 | int i; |
381 | char *str; | |
382 | } adns_rr_intstr; | |
383 | ||
384 | typedef struct { | |
61093792 | 385 | adns_rr_intstr array[2]; |
386 | } adns_rr_intstrpair; | |
387 | ||
388 | typedef struct { | |
389 | char *mname, *rname; | |
d05cc330 | 390 | unsigned long serial, refresh, retry, expire, minimum; |
391 | } adns_rr_soa; | |
6927715a | 392 | |
393 | typedef struct { | |
3db6be73 | 394 | int priority, weight, port; |
395 | char *host; | |
396 | } adns_rr_srvraw; | |
397 | ||
398 | typedef struct { | |
399 | int priority, weight, port; | |
400 | adns_rr_hostaddr ha; | |
2248cdf4 | 401 | } adns_rr_srvha; |
3db6be73 | 402 | |
403 | typedef struct { | |
7d0aaee4 | 404 | int len; |
405 | unsigned char *data; | |
406 | } adns_rr_byteblock; | |
407 | ||
408 | typedef struct { | |
5db99a2e | 409 | adns_status status; |
410 | char *cname; /* always NULL if query was for CNAME records */ | |
7aac35cd | 411 | char *owner; /* only set if req'd in query flags; maybe 0 on error anyway */ |
1e9efa71 | 412 | adns_rrtype type; /* guaranteed to be same as in query */ |
7aac35cd | 413 | time_t expires;/*abs time. def only if _s_ok, nxdomain or nodata. NOT TTL!*/ |
0872e289 | 414 | int nrrs, rrsz; /* nrrs is 0 if an error occurs */ |
5db99a2e | 415 | union { |
965c9782 | 416 | void *untyped; |
417 | unsigned char *bytes; | |
7aac35cd | 418 | char *(*str); /* ns_raw, cname, ptr, ptr_raw */ |
419 | adns_rr_intstr *(*manyistr); /* txt (list strs ends with i=-1, str=0)*/ | |
420 | adns_rr_addr *addr; /* addr */ | |
421 | struct in_addr *inaddr; /* a */ | |
9136cf0c | 422 | struct in6_addr *in6addr; /* aaaa */ |
7aac35cd | 423 | adns_rr_hostaddr *hostaddr; /* ns */ |
424 | adns_rr_intstrpair *intstrpair; /* hinfo */ | |
425 | adns_rr_strpair *strpair; /* rp, rp_raw */ | |
426 | adns_rr_inthostaddr *inthostaddr;/* mx */ | |
7d0aaee4 | 427 | adns_rr_intstr *intstr; /* mx_raw */ |
7aac35cd | 428 | adns_rr_soa *soa; /* soa, soa_raw */ |
3db6be73 | 429 | adns_rr_srvraw *srvraw; /* srv_raw */ |
2248cdf4 | 430 | adns_rr_srvha *srvha;/* srv */ |
7d0aaee4 | 431 | adns_rr_byteblock *byteblock; /* ...|unknown */ |
5db99a2e | 432 | } rrs; |
5617a135 | 433 | } adns_answer; |
5db99a2e | 434 | |
435 | /* Memory management: | |
436 | * adns_state and adns_query are actually pointers to malloc'd state; | |
437 | * On submission questions are copied, including the owner domain; | |
d05cc330 | 438 | * Answers are malloc'd as a single piece of memory; pointers in the |
439 | * answer struct point into further memory in the answer. | |
5db99a2e | 440 | * query_io: |
441 | * Must always be non-null pointer; | |
442 | * If *query_io is 0 to start with then any query may be returned; | |
443 | * If *query_io is !0 adns_query then only that query may be returned. | |
9be46d86 | 444 | * If the call is successful, *query_io, *answer_r, and *context_r |
445 | * will all be set. | |
5db99a2e | 446 | * Errors: |
74c94831 | 447 | * Return values are 0 or an errno value. |
448 | * | |
449 | * For _init, _init_strcfg, _submit and _synchronous, system errors | |
450 | * (eg, failure to create sockets, malloc failure, etc.) return errno | |
032b6358 | 451 | * values. EINVAL from _init et al means the configuration file |
452 | * is erroneous and cannot be parsed. | |
74c94831 | 453 | * |
454 | * For _wait and _check failures are reported in the answer | |
c6f9dc7b | 455 | * structure, and only 0, ESRCH or (for _check) EAGAIN is |
74c94831 | 456 | * returned: if no (appropriate) requests are done adns_check returns |
c6f9dc7b | 457 | * EAGAIN; if no (appropriate) requests are outstanding both |
74c94831 | 458 | * adns_query and adns_wait return ESRCH. |
459 | * | |
460 | * Additionally, _wait can return EINTR if you set adns_if_eintr. | |
461 | * | |
462 | * All other errors (nameserver failure, timed out connections, &c) | |
463 | * are returned in the status field of the answer. After a | |
464 | * successful _wait or _check, if status is nonzero then nrrs will be | |
465 | * 0, otherwise it will be >0. type will always be the type | |
466 | * requested. | |
5db99a2e | 467 | */ |
468 | ||
5448fc9f | 469 | /* Threads: |
470 | * adns does not use any static modifiable state, so it | |
471 | * is safe to call adns_init several times and then use the | |
472 | * resulting adns_states concurrently. | |
473 | * However, it is NOT safe to make simultaneous calls into | |
474 | * adns using the same adns_state; a single adns_state must be used | |
475 | * only by one thread at a time. You can solve this problem by | |
476 | * having one adns_state per thread, or if that isn't feasible, you | |
477 | * could maintain a pool of adns_states. Unfortunately neither of | |
478 | * these approaches has optimal performance. | |
479 | */ | |
480 | ||
edb95764 | 481 | int adns_init(adns_state *newstate_r, adns_initflags flags, |
d6b271ae | 482 | FILE *diagfile /*0=>stderr*/); |
483 | ||
edb95764 | 484 | int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags, |
d6b271ae | 485 | FILE *diagfile /*0=>discard*/, const char *configtext); |
38fcb64a | 486 | |
86ea5e62 | 487 | typedef void adns_logcallbackfn(adns_state ads, void *logfndata, |
488 | const char *fmt, va_list al); | |
489 | /* Will be called perhaps several times for each message; when the | |
490 | * message is complete, the string implied by fmt and al will end in | |
491 | * a newline. Log messages start with `adns debug:' or `adns | |
492 | * warning:' or `adns:' (for errors), or `adns debug [PID]:' | |
493 | * etc. if adns_if_logpid is set. */ | |
494 | ||
495 | int adns_init_logfn(adns_state *newstate_r, adns_initflags flags, | |
496 | const char *configtext /*0=>use default config files*/, | |
497 | adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */, | |
498 | void *logfndata /*0 with logfn==0 => discard*/); | |
499 | ||
38fcb64a | 500 | /* Configuration: |
501 | * adns_init reads /etc/resolv.conf, which is expected to be (broadly | |
45efc92a | 502 | * speaking) in the format expected by libresolv, and then |
503 | * /etc/resolv-adns.conf if it exists. adns_init_strcfg is instead | |
504 | * passed a string which is interpreted as if it were the contents of | |
505 | * resolv.conf or resolv-adns.conf. In general, configuration which | |
506 | * is set later overrides any that is set earlier. | |
38fcb64a | 507 | * |
45efc92a | 508 | * Standard directives understood in resolv[-adns].conf: |
38fcb64a | 509 | * |
510 | * nameserver <address> | |
511 | * Must be followed by the IP address of a nameserver. Several | |
512 | * nameservers may be specified, and they will be tried in the order | |
513 | * found. There is a compiled in limit, currently 5, on the number | |
514 | * of nameservers. (libresolv supports only 3 nameservers.) | |
515 | * | |
516 | * search <domain> ... | |
517 | * Specifies the search list for queries which specify | |
518 | * adns_qf_search. This is a list of domains to append to the query | |
519 | * domain. The query domain will be tried as-is either before all | |
520 | * of these or after them, depending on the ndots option setting | |
521 | * (see below). | |
522 | * | |
523 | * domain <domain> | |
524 | * This is present only for backward compatibility with obsolete | |
525 | * versions of libresolv. It should not be used, and is interpreted | |
526 | * by adns as if it were `search' - note that this is subtly | |
527 | * different to libresolv's interpretation of this directive. | |
528 | * | |
529 | * sortlist <addr>/<mask> ... | |
530 | * Should be followed by a sequence of IP-address and netmask pairs, | |
531 | * separated by spaces. They may be specified as | |
532 | * eg. 172.30.206.0/24 or 172.30.206.0/255.255.255.0. Currently up | |
533 | * to 15 pairs may be specified (but note that libresolv only | |
534 | * supports up to 10). | |
535 | * | |
536 | * options | |
537 | * Should followed by one or more options, separated by spaces. | |
538 | * Each option consists of an option name, followed by optionally | |
539 | * a colon and a value. Options are listed below. | |
540 | * | |
45efc92a | 541 | * Non-standard directives understood in resolv[-adns].conf: |
38fcb64a | 542 | * |
543 | * clearnameservers | |
544 | * Clears the list of nameservers, so that further nameserver lines | |
545 | * start again from the beginning. | |
546 | * | |
547 | * include <filename> | |
548 | * The specified file will be read. | |
549 | * | |
45efc92a | 550 | * Additionally, adns will ignore lines in resolv[-adns].conf which |
551 | * start with a #. | |
38fcb64a | 552 | * |
553 | * Standard options understood: | |
554 | * | |
555 | * debug | |
556 | * Enables debugging output from the resolver, which will be written | |
557 | * to stderr. | |
558 | * | |
559 | * ndots:<count> | |
560 | * Affects whether queries with adns_qf_search will be tried first | |
561 | * without adding domains from the searchlist, or whether the bare | |
562 | * query domain will be tried last. Queries which contain at least | |
563 | * <count> dots will be tried bare first. The default is 1. | |
564 | * | |
565 | * Non-standard options understood: | |
566 | * | |
567 | * adns_checkc:none | |
568 | * adns_checkc:entex | |
569 | * adns_checkc:freq | |
570 | * Changes the consistency checking frequency; this overrides the | |
571 | * setting of adns_if_check_entex, adns_if_check_freq, or neither, | |
572 | * in the flags passed to adns_init. | |
20078efc MW |
573 | * |
574 | * adns_af:v4only | |
575 | * adns_af:v6only | |
576 | * adns_af:any | |
577 | * Controls whether ADNS looks for IPv4 (A records) and IPv6 (AAAA | |
578 | * records) addresses when it's trying to build a socket address. | |
579 | * The default is `any' which means to allow both. The `sortlist' | |
580 | * directive can be used to control the relative preference of IPv4 | |
581 | * and IPv6 addresses if both are returned for the same query. | |
582 | * These override the corresponding init flags (covered by | |
583 | * adns_if_afmask). | |
38fcb64a | 584 | * |
585 | * There are a number of environment variables which can modify the | |
586 | * behaviour of adns. They take effect only if adns_init is used, and | |
587 | * the caller of adns_init can disable them using adns_if_noenv. In | |
588 | * each case there is both a FOO and an ADNS_FOO; the latter is | |
589 | * interpreted later so that it can override the former. Unless | |
590 | * otherwise stated, environment variables are interpreted after | |
45efc92a | 591 | * resolv[-adns].conf are read, in the order they are listed here. |
38fcb64a | 592 | * |
593 | * RES_CONF, ADNS_RES_CONF | |
594 | * A filename, whose contets are in the format of resolv.conf. | |
595 | * | |
596 | * RES_CONF_TEXT, ADNS_RES_CONF_TEXT | |
597 | * A string in the format of resolv.conf. | |
598 | * | |
599 | * RES_OPTIONS, ADNS_RES_OPTIONS | |
600 | * These are parsed as if they appeared in the `options' line of a | |
601 | * resolv.conf. In addition to being parsed at this point in the | |
602 | * sequence, they are also parsed at the very beginning before | |
603 | * resolv.conf or any other environment variables are read, so that | |
604 | * any debug option can affect the processing of the configuration. | |
605 | * | |
606 | * LOCALDOMAIN, ADNS_LOCALDOMAIN | |
607 | * These are interpreted as if their contents appeared in a `search' | |
608 | * line in resolv.conf. | |
609 | */ | |
5db99a2e | 610 | |
611 | int adns_synchronous(adns_state ads, | |
612 | const char *owner, | |
613 | adns_rrtype type, | |
edb95764 | 614 | adns_queryflags flags, |
9ab4dfce | 615 | adns_answer **answer_r); |
5617a135 | 616 | |
617 | /* NB: if you set adns_if_noautosys then _submit and _check do not | |
74c94831 | 618 | * make any system calls; you must use some of the asynch-io event |
619 | * processing functions to actually get things to happen. | |
5617a135 | 620 | */ |
5db99a2e | 621 | |
622 | int adns_submit(adns_state ads, | |
623 | const char *owner, | |
624 | adns_rrtype type, | |
edb95764 | 625 | adns_queryflags flags, |
5db99a2e | 626 | void *context, |
e7afa27f | 627 | adns_query *query_r); |
5db99a2e | 628 | |
bcf33879 | 629 | /* The owner should be quoted in master file format. */ |
630 | ||
e7afa27f | 631 | int adns_check(adns_state ads, |
5db99a2e | 632 | adns_query *query_io, |
9ab4dfce | 633 | adns_answer **answer_r, |
634 | void **context_r); | |
5db99a2e | 635 | |
636 | int adns_wait(adns_state ads, | |
637 | adns_query *query_io, | |
9ab4dfce | 638 | adns_answer **answer_r, |
639 | void **context_r); | |
5db99a2e | 640 | |
ef20fccf | 641 | /* same as adns_wait but uses poll(2) internally */ |
642 | int adns_wait_poll(adns_state ads, | |
643 | adns_query *query_io, | |
644 | adns_answer **answer_r, | |
645 | void **context_r); | |
646 | ||
11c8bf9b | 647 | void adns_cancel(adns_query query); |
5db99a2e | 648 | |
74c94831 | 649 | /* The adns_query you get back from _submit is valid (ie, can be |
650 | * legitimately passed into adns functions) until it is returned by | |
651 | * adns_check or adns_wait, or passed to adns_cancel. After that it | |
652 | * must not be used. You can rely on it not being reused until the | |
653 | * first adns_submit or _transact call using the same adns_state after | |
654 | * it became invalid, so you may compare it for equality with other | |
655 | * query handles until you next call _query or _transact. | |
125de2a9 | 656 | * |
657 | * _submit and _synchronous return ENOSYS if they don't understand the | |
658 | * query type. | |
74c94831 | 659 | */ |
660 | ||
0872e289 | 661 | int adns_submit_reverse(adns_state ads, |
662 | const struct sockaddr *addr, | |
663 | adns_rrtype type, | |
edb95764 | 664 | adns_queryflags flags, |
0872e289 | 665 | void *context, |
666 | adns_query *query_r); | |
5e6342f0 | 667 | /* type must be _r_ptr or _r_ptr_raw. _qf_search is ignored. |
668 | * addr->sa_family must be AF_INET or you get ENOSYS. | |
669 | */ | |
0872e289 | 670 | |
d2f6d877 | 671 | int adns_submit_reverse_any(adns_state ads, |
672 | const struct sockaddr *addr, | |
673 | const char *rzone, | |
674 | adns_rrtype type, | |
675 | adns_queryflags flags, | |
676 | void *context, | |
677 | adns_query *query_r); | |
678 | /* For RBL-style reverse `zone's; look up | |
679 | * <reversed-address>.<zone> | |
680 | * Any type is allowed. _qf_search is ignored. | |
681 | * addr->sa_family must be AF_INET or you get ENOSYS. | |
682 | */ | |
683 | ||
74c94831 | 684 | void adns_finish(adns_state ads); |
98db6da3 | 685 | /* You may call this even if you have queries outstanding; |
686 | * they will be cancelled. | |
687 | */ | |
5db99a2e | 688 | |
1a9d7092 IJ |
689 | #define ADNS_ADDR2TEXT_BUFLEN \ |
690 | (INET6_ADDRSTRLEN + 1/*%*/ \ | |
691 | + ((IF_NAMESIZE-1) > 9 ? (IF_NAMESIZE-1) : 9/*uint32*/) \ | |
692 | + 1/* nul; included in IF_NAMESIZE */) | |
504877d1 | 693 | |
1a36f664 | 694 | int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags, |
7efa5bdc IJ |
695 | struct sockaddr *sa_r, |
696 | socklen_t *salen_io /* updated iff OK or ENOSPC */); | |
1a36f664 | 697 | int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags, |
7efa5bdc | 698 | char *buffer, int *buflen_io /* updated ONLY on ENOSPC */, |
b0f1ed64 | 699 | int *port_r /* may be 0 */); |
1a36f664 | 700 | /* |
504877d1 IJ |
701 | * port is always in host byte order and is simply copied to and |
702 | * from the appropriate sockaddr field (byteswapped as necessary). | |
1a36f664 IJ |
703 | * |
704 | * The only flags supported are adns_qf_addrlit_...; others are | |
705 | * ignored. | |
706 | * | |
707 | * Error return values are: | |
708 | * | |
709 | * ENOSPC Output buffer is too small. Can only happen if | |
7efa5bdc IJ |
710 | * *buflen_io < ADNS_ADDR2TEXT_BUFLEN or |
711 | * *salen_io < sizeof(adns_sockaddr). On return, | |
712 | * *buflen_io or *salen_io has been updated by adns. | |
1a36f664 IJ |
713 | * |
714 | * EINVAL text has invalid syntax. | |
715 | * | |
716 | * text represents an address family not supported by | |
717 | * this version of adns. | |
718 | * | |
719 | * Scoped address supplied (text contained "%" or | |
720 | * sin6_scope_id nonzero) but caller specified | |
721 | * adns_qf_addrlit_scope_forbid. | |
722 | * | |
71a5b6fc IJ |
723 | * Scope name (rather than number) supplied in text but |
724 | * caller specified adns_qf_addrlit_scope_numeric. | |
1a36f664 IJ |
725 | * |
726 | * EAFNOSUPPORT sa->sa_family is not supported (addr2text only). | |
727 | * | |
728 | * Only if neither adns_qf_addrlit_scope_forbid nor | |
729 | * adns_qf_addrlit_scope_numeric are set: | |
730 | * | |
731 | * ENOSYS Scope name supplied in text but IPv6 address part of | |
732 | * sockaddr is not a link local address. | |
733 | * | |
734 | * ENXIO Scope name supplied in text but if_nametoindex | |
735 | * said it wasn't a valid local interface name. | |
736 | * | |
737 | * EIO Scoped address supplied but if_nametoindex failed | |
738 | * in an unexpected way; adns has printed a message to | |
739 | * stderr. | |
740 | * | |
741 | * any other if_nametoindex failed in a more-or-less expected way. | |
504877d1 | 742 | */ |
e7afa27f | 743 | |
23dca174 | 744 | void adns_forallqueries_begin(adns_state ads); |
8f2aa812 | 745 | adns_query adns_forallqueries_next(adns_state ads, void **context_r); |
74c94831 | 746 | /* Iterator functions, which you can use to loop over the outstanding |
23dca174 | 747 | * (submitted but not yet successfuly checked/waited) queries. |
74c94831 | 748 | * |
23dca174 | 749 | * You can only have one iteration going at once. You may call _begin |
750 | * at any time; after that, an iteration will be in progress. You may | |
751 | * only call _next when an iteration is in progress - anything else | |
752 | * may coredump. The iteration remains in progress until _next | |
753 | * returns 0, indicating that all the queries have been walked over, | |
754 | * or ANY other adns function is called with the same adns_state (or a | |
755 | * query in the same adns_state). There is no need to explicitly | |
756 | * finish an iteration. | |
757 | * | |
8f2aa812 | 758 | * context_r may be 0. *context_r may not be set when _next returns 0. |
e7afa27f | 759 | */ |
5db99a2e | 760 | |
2ac463bf | 761 | void adns_checkconsistency(adns_state ads, adns_query qu); |
1389dc72 | 762 | /* Checks the consistency of adns's internal data structures. |
763 | * If any error is found, the program will abort(). | |
2ac463bf | 764 | * You may pass 0 for qu; if you pass non-null then additional checks |
765 | * are done to make sure that qu is a valid query. | |
1389dc72 | 766 | */ |
767 | ||
74c94831 | 768 | /* |
769 | * Example expected/legal calling sequence for submit/check/wait: | |
5db99a2e | 770 | * adns_init |
771 | * adns_submit 1 | |
772 | * adns_submit 2 | |
773 | * adns_submit 3 | |
774 | * adns_wait 1 | |
c6f9dc7b | 775 | * adns_check 3 -> EAGAIN |
5db99a2e | 776 | * adns_wait 2 |
777 | * adns_wait 3 | |
778 | * .... | |
779 | * adns_finish | |
74c94831 | 780 | */ |
781 | ||
782 | /* | |
783 | * Entrypoints for generic asynch io: | |
784 | * (these entrypoints are not very useful except in combination with * | |
785 | * some of the other I/O model calls which can tell you which fds to | |
786 | * be interested in): | |
787 | * | |
788 | * Note that any adns call may cause adns to open and close fds, so | |
789 | * you must call beforeselect or beforepoll again just before | |
790 | * blocking, or you may not have an up-to-date list of it's fds. | |
791 | */ | |
792 | ||
793 | int adns_processany(adns_state ads); | |
794 | /* Gives adns flow-of-control for a bit. This will never block, and | |
795 | * can be used with any threading/asynch-io model. If some error | |
796 | * occurred which might cause an event loop to spin then the errno | |
797 | * value is returned. | |
798 | */ | |
799 | ||
800 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now); | |
801 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now); | |
802 | int adns_processexceptional(adns_state ads, int fd, const struct timeval *now); | |
803 | /* Gives adns flow-of-control so that it can process incoming data | |
804 | * from, or send outgoing data via, fd. Very like _processany. If it | |
805 | * returns zero then fd will no longer be readable or writeable | |
806 | * (unless of course more data has arrived since). adns will _only_ | |
7a1ae5ac | 807 | * use that fd and only in the manner specified, regardless of whether |
74c94831 | 808 | * adns_if_noautosys was specified. |
809 | * | |
810 | * adns_processexceptional should be called when select(2) reports an | |
811 | * exceptional condition, or poll(2) reports POLLPRI. | |
812 | * | |
813 | * It is fine to call _processreabable or _processwriteable when the | |
814 | * fd is not ready, or with an fd that doesn't belong to adns; it will | |
815 | * then just return 0. | |
816 | * | |
817 | * If some error occurred which might prevent an event loop to spin | |
818 | * then the errno value is returned. | |
819 | */ | |
820 | ||
821 | void adns_processtimeouts(adns_state ads, const struct timeval *now); | |
822 | /* Gives adns flow-of-control so that it can process any timeouts | |
823 | * which might have happened. Very like _processreadable/writeable. | |
824 | * | |
825 | * now may be 0; if it isn't, *now must be the current time, recently | |
826 | * obtained from gettimeofday. | |
827 | */ | |
828 | ||
829 | void adns_firsttimeout(adns_state ads, | |
830 | struct timeval **tv_mod, struct timeval *tv_buf, | |
831 | struct timeval now); | |
832 | /* Asks adns when it would first like the opportunity to time | |
833 | * something out. now must be the current time, from gettimeofday. | |
834 | * | |
835 | * If tv_mod points to 0 then tv_buf must be non-null, and | |
836 | * _firsttimeout will fill in *tv_buf with the time until the first | |
837 | * timeout, and make *tv_mod point to tv_buf. If adns doesn't have | |
838 | * anything that might need timing out it will leave *tv_mod as 0. | |
839 | * | |
840 | * If *tv_mod is not 0 then tv_buf is not used. adns will update | |
841 | * *tv_mod if it has any earlier timeout, and leave it alone if it | |
842 | * doesn't. | |
843 | * | |
844 | * This call will not actually do any I/O, or change the fds that adns | |
845 | * is using. It always succeeds and never blocks. | |
846 | */ | |
847 | ||
848 | void adns_globalsystemfailure(adns_state ads); | |
849 | /* If serious problem(s) happen which globally affect your ability to | |
850 | * interact properly with adns, or adns's ability to function | |
851 | * properly, you or adns can call this function. | |
852 | * | |
853 | * All currently outstanding queries will be made to fail with | |
854 | * adns_s_systemfail, and adns will close any stream sockets it has | |
855 | * open. | |
856 | * | |
857 | * This is used by adns, for example, if gettimeofday() fails. | |
858 | * Without this the program's event loop might start to spin ! | |
859 | * | |
860 | * This call will never block. | |
861 | */ | |
862 | ||
863 | /* | |
864 | * Entrypoints for select-loop based asynch io: | |
865 | */ | |
866 | ||
867 | void adns_beforeselect(adns_state ads, int *maxfd, fd_set *readfds, | |
868 | fd_set *writefds, fd_set *exceptfds, | |
869 | struct timeval **tv_mod, struct timeval *tv_buf, | |
870 | const struct timeval *now); | |
871 | /* Find out file descriptors adns is interested in, and when it would | |
872 | * like the opportunity to time something out. If you do not plan to | |
873 | * block then tv_mod may be 0. Otherwise, tv_mod and tv_buf are as | |
874 | * for adns_firsttimeout. readfds, writefds, exceptfds and maxfd_io may | |
875 | * not be 0. | |
876 | * | |
86ea5e62 | 877 | * If tv_mod is 0 on entry then this will never actually do any I/O, |
878 | * or change the fds that adns is using or the timeouts it wants. In | |
879 | * any case it won't block, and it will set the timeout to zero if a | |
880 | * query finishes in _beforeselect. | |
74c94831 | 881 | */ |
882 | ||
883 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, | |
884 | const fd_set *writefds, const fd_set *exceptfds, | |
885 | const struct timeval *now); | |
886 | /* Gives adns flow-of-control for a bit; intended for use after | |
887 | * select. This is just a fancy way of calling adns_processreadable/ | |
888 | * writeable/timeouts as appropriate, as if select had returned the | |
889 | * data being passed. Always succeeds. | |
890 | */ | |
891 | ||
892 | /* | |
893 | * Example calling sequence: | |
5db99a2e | 894 | * |
5617a135 | 895 | * adns_init _noautosys |
5db99a2e | 896 | * loop { |
74c94831 | 897 | * adns_beforeselect |
5db99a2e | 898 | * select |
74c94831 | 899 | * adns_afterselect |
5617a135 | 900 | * ... |
901 | * adns_submit / adns_check | |
902 | * ... | |
5db99a2e | 903 | * } |
904 | */ | |
905 | ||
74c94831 | 906 | /* |
907 | * Entrypoints for poll-loop based asynch io: | |
908 | */ | |
909 | ||
910 | struct pollfd; | |
911 | /* In case your system doesn't have it or you forgot to include | |
912 | * <sys/poll.h>, to stop the following declarations from causing | |
913 | * problems. If your system doesn't have poll then the following | |
914 | * entrypoints will not be defined in libadns. Sorry ! | |
915 | */ | |
916 | ||
7aac35cd | 917 | int adns_beforepoll(adns_state ads, struct pollfd *fds, |
918 | int *nfds_io, int *timeout_io, | |
74c94831 | 919 | const struct timeval *now); |
920 | /* Finds out which fd's adns is interested in, and when it would like | |
921 | * to be able to time things out. This is in a form suitable for use | |
922 | * with poll(2). | |
923 | * | |
924 | * On entry, usually fds should point to at least *nfds_io structs. | |
925 | * adns will fill up to that many structs will information for poll, | |
926 | * and record in *nfds_io how many structs it filled. If it wants to | |
927 | * listen for more structs then *nfds_io will be set to the number | |
928 | * required and _beforepoll will return ERANGE. | |
929 | * | |
74c94831 | 930 | * You may call _beforepoll with fds==0 and *nfds_io 0, in which case |
931 | * adns will fill in the number of fds that it might be interested in | |
4f973eb5 | 932 | * in *nfds_io, and always return either 0 (if it is not interested in |
933 | * any fds) or ERANGE (if it is). | |
934 | * | |
dd9cf93b | 935 | * NOTE that (unless now is 0) adns may acquire additional fds |
4f973eb5 | 936 | * from one call to the next, so you must put adns_beforepoll in a |
937 | * loop, rather than assuming that the second call (with the buffer | |
938 | * size requested by the first) will not return ERANGE. | |
74c94831 | 939 | * |
940 | * adns only ever sets POLLIN, POLLOUT and POLLPRI in its pollfd | |
941 | * structs, and only ever looks at those bits. POLLPRI is required to | |
4f973eb5 | 942 | * detect TCP Urgent Data (which should not be used by a DNS server) |
74c94831 | 943 | * so that adns can know that the TCP stream is now useless. |
944 | * | |
945 | * In any case, *timeout_io should be a timeout value as for poll(2), | |
946 | * which adns will modify downwards as required. If the caller does | |
4f973eb5 | 947 | * not plan to block then *timeout_io should be 0 on entry, or |
948 | * alternatively, timeout_io may be 0. (Alternatively, the caller may | |
949 | * use _beforeselect with timeout_io==0 to find out about file | |
950 | * descriptors, and use _firsttimeout is used to find out when adns | |
951 | * might want to time something out.) | |
74c94831 | 952 | * |
953 | * adns_beforepoll will return 0 on success, and will not fail for any | |
954 | * reason other than the fds buffer being too small (ERANGE). | |
955 | * | |
dd9cf93b | 956 | * This call will never actually do any I/O. If you supply the |
957 | * current time it will not change the fds that adns is using or the | |
958 | * timeouts it wants. | |
959 | * | |
960 | * In any case this call won't block. | |
74c94831 | 961 | */ |
962 | ||
705b9b15 | 963 | #define ADNS_POLLFDS_RECOMMENDED 3 |
74c94831 | 964 | /* If you allocate an fds buf with at least RECOMMENDED entries then |
965 | * you are unlikely to need to enlarge it. You are recommended to do | |
966 | * so if it's convenient. However, you must be prepared for adns to | |
967 | * require more space than this. | |
968 | */ | |
969 | ||
970 | void adns_afterpoll(adns_state ads, const struct pollfd *fds, int nfds, | |
971 | const struct timeval *now); | |
972 | /* Gives adns flow-of-control for a bit; intended for use after | |
973 | * poll(2). fds and nfds should be the results from poll(). pollfd | |
974 | * structs mentioning fds not belonging to adns will be ignored. | |
975 | */ | |
976 | ||
977 | ||
1e9efa71 | 978 | adns_status adns_rr_info(adns_rrtype type, |
979 | const char **rrtname_r, const char **fmtname_r, | |
980 | int *len_r, | |
981 | const void *datap, char **data_r); | |
0872e289 | 982 | /* |
0872e289 | 983 | * Get information about a query type, or convert reply data to a |
984 | * textual form. type must be specified, and the official name of the | |
985 | * corresponding RR type will be returned in *rrtname_r, and | |
986 | * information about the processing style in *fmtname_r. The length | |
987 | * of the table entry in an answer for that type will be returned in | |
988 | * in *len_r. Any or all of rrtname_r, fmtname_r and len_r may be 0. | |
989 | * If fmtname_r is non-null then *fmtname_r may be null on return, | |
990 | * indicating that no special processing is involved. | |
991 | * | |
992 | * data_r be must be non-null iff datap is. In this case *data_r will | |
993 | * be set to point to a string pointing to a representation of the RR | |
994 | * data in master file format. (The owner name, timeout, class and | |
995 | * type will not be present - only the data part of the RR.) The | |
996 | * memory will have been obtained from malloc() and must be freed by | |
997 | * the caller. | |
1e9efa71 | 998 | * |
999 | * Usually this routine will succeed. Possible errors include: | |
1000 | * adns_s_nomemory | |
9b86645c | 1001 | * adns_s_rrtypeunknown |
1e9efa71 | 1002 | * adns_s_invaliddata (*datap contained garbage) |
1003 | * If an error occurs then no memory has been allocated, | |
1004 | * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined. | |
0872e289 | 1005 | * |
1006 | * There are some adns-invented data formats which are not official | |
1007 | * master file formats. These include: | |
1008 | * | |
1009 | * Mailboxes if __qtf_mail822: these are just included as-is. | |
1010 | * | |
1011 | * Addresses (adns_rr_addr): these may be of pretty much any type. | |
1012 | * The representation is in two parts: first, a word for the address | |
1013 | * family (ie, in AF_XXX, the XXX), and then one or more items for the | |
1014 | * address itself, depending on the format. For an IPv4 address the | |
1015 | * syntax is INET followed by the dotted quad (from inet_ntoa). | |
1016 | * Currently only IPv4 is supported. | |
1017 | * | |
0fb18816 | 1018 | * Text strings (as in adns_rr_txt) appear inside double quotes, and |
1019 | * use \" and \\ to represent " and \, and \xHH to represent | |
1020 | * characters not in the range 32-126. | |
1021 | * | |
0872e289 | 1022 | * Hostname with addresses (adns_rr_hostaddr): this consists of the |
0fb18816 | 1023 | * hostname, as usual, followed by the adns_status value, as an |
1024 | * abbreviation, and then a descriptive string (encoded as if it were | |
1025 | * a piece of text), for the address lookup, followed by zero or more | |
eaf858ea | 1026 | * addresses enclosed in ( and ). If the result was a temporary |
0872e289 | 1027 | * failure, then a single ? appears instead of the ( ). If the |
eaf858ea | 1028 | * result was a permanent failure then an empty pair of parentheses |
0872e289 | 1029 | * appears (which a space in between). For example, one of the NS |
0fb18816 | 1030 | * records for greenend.org.uk comes out like |
1031 | * ns.chiark.greenend.org.uk ok "OK" ( INET 195.224.76.132 ) | |
0872e289 | 1032 | * an MX referring to a nonexistent host might come out like: |
0fb18816 | 1033 | * 50 sun2.nsfnet-relay.ac.uk nxdomain "No such domain" ( ) |
0872e289 | 1034 | * and if nameserver information is not available you might get: |
0fb18816 | 1035 | * dns2.spong.dyn.ml.org timeout "DNS query timed out" ? |
1e9efa71 | 1036 | */ |
1037 | ||
7f702335 | 1038 | const char *adns_strerror(adns_status st); |
c2875680 | 1039 | const char *adns_errabbrev(adns_status st); |
9e50e3ac | 1040 | const char *adns_errtypeabbrev(adns_status st); |
74c94831 | 1041 | /* Like strerror but for adns_status values. adns_errabbrev returns |
1042 | * the abbreviation of the error - eg, for adns_s_timeout it returns | |
9e50e3ac | 1043 | * "timeout". adns_errtypeabbrev returns the abbreviation of the |
1044 | * error class: ie, for values up to adns_s_max_XXX it will return the | |
1045 | * string XXX. You MUST NOT call these functions with status values | |
74c94831 | 1046 | * not returned by the same adns library. |
1047 | */ | |
7f702335 | 1048 | |
62049492 | 1049 | #ifdef __cplusplus |
1050 | } /* end of extern "C" */ | |
1051 | #endif | |
5db99a2e | 1052 | #endif |