3 * - adns user-visible API (single-threaded, without any locking)
6 * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software Foundation,
20 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 #ifndef ADNS_H_INCLUDED
26 #define ADNS_H_INCLUDED
30 #include <sys/socket.h>
31 #include <netinet/in.h>
33 /* All struct in_addr anywhere in adns are in NETWORK byte order. */
35 typedef struct adns__state *adns_state;
36 typedef struct adns__query *adns_query;
39 adns_if_noenv= 0x0001, /* do not look at environment */
40 adns_if_noerrprint= 0x0002, /* never print output to stderr (_debug overrides) */
41 adns_if_noserverwarn= 0x0004, /* do not warn to stderr about duff nameservers etc */
42 adns_if_debug= 0x0008, /* enable all output to stderr plus debug msgs */
43 adns_if_noautosys= 0x0010, /* do not make syscalls at every opportunity */
44 adns_if_eintr= 0x0020, /* allow _wait and _synchronous to return EINTR */
48 adns_qf_search= 0x000001, /* use the searchlist */
49 adns_qf_usevc= 0x000002, /* use a virtual circuit (TCP connection) */
50 adns_qf_quoteok_query= 0x000010, /* allow quote-requiring chars in query domain */
51 adns_qf_quoteok_cname= 0x000020, /* allow ... in CNAME we go via */
52 adns_qf_quoteok_anshost= 0x000040, /* allow ... in answers expected to be hostnames */
53 adns_qf_cname_loose= 0x000100, /* allow refs to CNAMEs - without, get _s_cname */
54 adns_qf_cname_forbid= 0x000200, /* don't follow CNAMEs, instead give _s_cname */
55 adns__qf_internalmask= 0x0ff000
59 adns__rrt_typemask= 0x0ffff,
60 adns__qtf_deref= 0x10000, /* dereference domains and perhaps produce extra data */
61 adns__qtf_mail822= 0x20000, /* make mailboxes be in RFC822 rcpt field format */
68 adns_r_ns= adns_r_ns_raw|adns__qtf_deref,
73 adns_r_soa= adns_r_soa_raw|adns__qtf_mail822,
76 adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref,
81 adns_r_mx= adns_r_mx_raw|adns__qtf_deref,
86 adns_r_rp= adns_r_rp_raw|adns__qtf_mail822,
88 adns_r_addr= adns_r_a|adns__qtf_deref
92 /* In queries without qtf_quoteok_*, all domains must have standard
93 * legal syntax. In queries _with_ qtf_anyquote, domains in the query
94 * or response may contain any characters, quoted according to
95 * RFC1035 5.1. On input to adns, the char* is a pointer to the
96 * interior of a " delimited string, except that " may appear in it,
97 * and on output, the char* is a pointer to a string which would be
98 * legal either inside or outside " delimiters, and any characters
99 * not usually legal in domain names will be quoted as \X
100 * (if the character is 33-126 except \ and ") or \DDD.
102 * Do not ask for _raw records containing mailboxes without
103 * specifying _qf_anyquote.
109 /* locally induced errors */
111 adns_s_unknownrrtype,
113 /* remotely induced errors, detected locally */
117 adns_s_invalidresponse,
118 adns_s_unknownformat,
120 /* remotely induced errors, reported by remote server to us */
121 adns_s_rcodeservfail,
122 adns_s_rcodeformaterror,
123 adns_s_rcodenotimplemented,
127 adns_s_max_tempfail= 99,
129 /* remote configuration errors */
130 adns_s_inconsistent, /* PTR gives domain whose A does not exist and match */
131 adns_s_prohibitedcname, /* CNAME found where eg A expected (not if _qf_loosecname) */
132 adns_s_answerdomaininvalid,
133 adns_s_answerdomaintoolong,
136 adns_s_max_misconfig= 199,
138 /* permanent problems with the query */
139 adns_s_querydomainwrong,
140 adns_s_querydomaininvalid,
141 adns_s_querydomaintoolong,
143 adns_s_max_misquery= 299,
145 /* permanent errors */
155 struct sockaddr_in inet;
162 int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */
173 } adns_rr_inthostaddr;
176 /* Used both for mx_raw, in which case i is the preference and str the domain,
177 * and for txt, in which case each entry has i for the `text' length,
178 * and str for the data (which will have had an extra nul appended
179 * so that if it was plain text it is now a null-terminated string).
186 adns_rr_intstr array[2];
187 } adns_rr_intstrpair;
191 unsigned long serial, refresh, retry, expire, minimum;
196 char *cname; /* always NULL if query was for CNAME records */
197 adns_rrtype type; /* guaranteed to be same as in query */
198 time_t expires; /* expiry time, defined only if _s_ok, nxdomain or nodata. NOT TTL! */
202 unsigned char *bytes;
203 char *(*str); /* ns_raw, cname, ptr, ptr_raw */
204 adns_rr_intstr *(*manyistr); /* txt (list of strings ends with i=-1, str=0) */
205 adns_rr_addr *addr; /* addr */
206 struct in_addr *inaddr; /* a */
207 adns_rr_hostaddr *hostaddr; /* ns */
208 adns_rr_intstrpair *intstrpair; /* hinfo */
209 adns_rr_strpair *strpair; /* rp, rp_raw */
210 adns_rr_inthostaddr *inthostaddr; /* mx */
211 adns_rr_intstr *intstr; /* mx_raw */
212 adns_rr_soa *soa; /* soa, soa_raw */
216 /* Memory management:
217 * adns_state and adns_query are actually pointers to malloc'd state;
218 * On submission questions are copied, including the owner domain;
219 * Answers are malloc'd as a single piece of memory; pointers in the
220 * answer struct point into further memory in the answer.
222 * Must always be non-null pointer;
223 * If *query_io is 0 to start with then any query may be returned;
224 * If *query_io is !0 adns_query then only that query may be returned.
225 * If the call is successful, *query_io, *answer_r, and *context_r
228 * Return values are 0 or an errno value;
229 * Seriously fatal system errors (eg, failure to create sockets,
230 * malloc failure, etc.) return errno values;
231 * Other errors (nameserver failure, timed out connections, &c)
232 * are returned in the status field of the answer. If status is
233 * nonzero then nrrs will be 0, otherwise it will be >0.
234 * type will always be the type requested;
235 * If no (appropriate) requests are done adns_check returns EWOULDBLOCK;
236 * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH;
239 int adns_init(adns_state *newstate_r, adns_initflags flags,
240 FILE *diagfile /*0=>stderr*/);
242 int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags,
243 FILE *diagfile /*0=>discard*/, const char *configtext);
245 int adns_synchronous(adns_state ads,
248 adns_queryflags flags,
249 adns_answer **answer_r);
251 /* NB: if you set adns_if_noautosys then _submit and _check do not
252 * make any system calls; you must use adns_callback (possibly after
253 * adns_interest) to actually get things to happen.
256 int adns_submit(adns_state ads,
259 adns_queryflags flags,
261 adns_query *query_r);
263 int adns_check(adns_state ads,
264 adns_query *query_io,
265 adns_answer **answer_r,
268 int adns_wait(adns_state ads,
269 adns_query *query_io,
270 adns_answer **answer_r,
272 /* fixme: minor cache */
274 void adns_cancel(adns_query query);
276 void adns_finish(adns_state);
277 /* You may call this even if you have queries outstanding;
278 * they will be cancelled.
281 int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds,
282 const fd_set *exceptfds);
283 /* Gives adns flow-of-control for a bit. This will never block.
284 * If maxfd == -1 then adns will check (make nonblocking system calls on)
285 * all of its own filedescriptors; otherwise it will only use those
286 * < maxfd and specified in the fd_set's, as if select had returned them.
287 * Other fd's may be in the fd_sets, and will be ignored.
288 * _callback returns how many adns fd's were in the various sets, so
289 * you can tell if your select handling code has missed something and is going awol.
291 * May also return -1 if a critical syscall failed, setting errno.
294 void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io,
295 fd_set *writefds_io, fd_set *exceptfds_io,
296 struct timeval **tv_mod, struct timeval *tv_buf);
297 /* Find out file descriptors adns is interested in, and when it
298 * would like the opportunity to time something out. If you do not plan to
299 * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning
300 * you have no timeout of your own, in which case tv_buf must be non-null and
301 * _interest may fill it in and set *tv_mod=tv_buf.
302 * readfds, writefds, exceptfds and maxfd may not be 0.
305 /* Example expected/legal calling sequences:
311 * adns_check 3 -> EWOULDBLOCK
317 * adns_init _noautosys
323 * adns_submit / adns_check
328 adns_status adns_rr_info(adns_rrtype type,
329 const char **rrtname_r, const char **fmtname_r,
331 const void *datap, char **data_r);
332 /* Gets information in human-readable (but non-i18n) form
333 * for eg debugging purposes. type must be specified,
334 * and the official name of the corresponding RR type will
335 * be returned in *rrtname_r, and information about the processing
336 * style in *fmtname_r. The length of the table entry in an answer
337 * for that type will be returned in in *len_r.
338 * Any or all of rrtname_r, fmtname_r and len_r may be 0.
339 * If fmtname_r is non-null then *fmtname_r may be
340 * null on return, indicating that no special processing is
343 * data_r be must be non-null iff datap is. In this case
344 * *data_r will be set to point to a human-readable text
345 * string representing the RR data. The text will have
346 * been obtained from malloc() and must be freed by the caller.
348 * Usually this routine will succeed. Possible errors include:
350 * adns_s_rrtypeunknown
351 * adns_s_invaliddata (*datap contained garbage)
352 * If an error occurs then no memory has been allocated,
353 * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined.
356 const char *adns_strerror(adns_status st);