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 */
45 adns_if_nosigpipe
= 0x0040, /* applic has SIGPIPE set to SIG_IGN, do not protect */
49 adns_qf_search
= 0x000001, /* use the searchlist */
50 adns_qf_usevc
= 0x000002, /* use a virtual circuit (TCP connection) */
51 adns_qf_owner
= 0x000004, /* fill in the owner field in the answer */
52 adns_qf_quoteok_query
= 0x000010, /* allow quote-requiring chars in query domain */
53 adns_qf_quoteok_cname
= 0x000020, /* allow ... in CNAME we go via */
54 adns_qf_quoteok_anshost
= 0x000040, /* allow ... in answers expected to be hostnames */
55 adns_qf_cname_loose
= 0x000100, /* allow refs to CNAMEs - without, get _s_cname */
56 adns_qf_cname_forbid
= 0x000200, /* don't follow CNAMEs, instead give _s_cname */
57 adns__qf_internalmask
= 0x0ff000
61 adns__rrt_typemask
= 0x0ffff,
62 adns__qtf_deref
= 0x10000, /* dereference domains and perhaps produce extra data */
63 adns__qtf_mail822
= 0x20000, /* make mailboxes be in RFC822 rcpt field format */
70 adns_r_ns
= adns_r_ns_raw
|adns__qtf_deref
,
75 adns_r_soa
= adns_r_soa_raw
|adns__qtf_mail822
,
78 adns_r_ptr
= adns_r_ptr_raw
|adns__qtf_deref
,
83 adns_r_mx
= adns_r_mx_raw
|adns__qtf_deref
,
88 adns_r_rp
= adns_r_rp_raw
|adns__qtf_mail822
,
90 adns_r_addr
= adns_r_a
|adns__qtf_deref
94 /* In queries without qtf_quoteok_*, all domains must have standard
95 * legal syntax. In queries _with_ qtf_anyquote, domains in the query
96 * or response may contain any characters, quoted according to
97 * RFC1035 5.1. On input to adns, the char* is a pointer to the
98 * interior of a " delimited string, except that " may appear in it,
99 * and on output, the char* is a pointer to a string which would be
100 * legal either inside or outside " delimiters, and any characters
101 * not usually legal in domain names will be quoted as \X
102 * (if the character is 33-126 except \ and ") or \DDD.
104 * Do not ask for _raw records containing mailboxes without
105 * specifying _qf_anyquote.
111 /* locally induced errors */
113 adns_s_unknownrrtype
,
115 /* remotely induced errors, detected locally */
119 adns_s_invalidresponse
,
120 adns_s_unknownformat
,
122 /* remotely induced errors, reported by remote server to us */
123 adns_s_rcodeservfail
,
124 adns_s_rcodeformaterror
,
125 adns_s_rcodenotimplemented
,
129 adns_s_max_tempfail
= 99,
131 /* remote configuration errors */
132 adns_s_inconsistent
, /* PTR gives domain whose A does not exist and match */
133 adns_s_prohibitedcname
, /* CNAME found where eg A expected (not if _qf_loosecname) */
134 adns_s_answerdomaininvalid
,
135 adns_s_answerdomaintoolong
,
138 adns_s_max_misconfig
= 199,
140 /* permanent problems with the query */
141 adns_s_querydomainwrong
,
142 adns_s_querydomaininvalid
,
143 adns_s_querydomaintoolong
,
145 adns_s_max_misquery
= 299,
147 /* permanent errors */
157 struct sockaddr_in inet
;
164 int naddrs
; /* temp fail => -1, perm fail => 0, s_ok => >0 */
175 } adns_rr_inthostaddr
;
178 /* Used both for mx_raw, in which case i is the preference and str the domain,
179 * and for txt, in which case each entry has i for the `text' length,
180 * and str for the data (which will have had an extra nul appended
181 * so that if it was plain text it is now a null-terminated string).
188 adns_rr_intstr array
[2];
189 } adns_rr_intstrpair
;
193 unsigned long serial
, refresh
, retry
, expire
, minimum
;
198 char *cname
; /* always NULL if query was for CNAME records */
199 char *owner
; /* only set if requested in query flags */
200 adns_rrtype type
; /* guaranteed to be same as in query */
201 time_t expires
; /* expiry time, defined only if _s_ok, nxdomain or nodata. NOT TTL! */
205 unsigned char *bytes
;
206 char *(*str
); /* ns_raw, cname, ptr, ptr_raw */
207 adns_rr_intstr
*(*manyistr
); /* txt (list of strings ends with i=-1, str=0) */
208 adns_rr_addr
*addr
; /* addr */
209 struct in_addr
*inaddr
; /* a */
210 adns_rr_hostaddr
*hostaddr
; /* ns */
211 adns_rr_intstrpair
*intstrpair
; /* hinfo */
212 adns_rr_strpair
*strpair
; /* rp, rp_raw */
213 adns_rr_inthostaddr
*inthostaddr
; /* mx */
214 adns_rr_intstr
*intstr
; /* mx_raw */
215 adns_rr_soa
*soa
; /* soa, soa_raw */
219 /* Memory management:
220 * adns_state and adns_query are actually pointers to malloc'd state;
221 * On submission questions are copied, including the owner domain;
222 * Answers are malloc'd as a single piece of memory; pointers in the
223 * answer struct point into further memory in the answer.
225 * Must always be non-null pointer;
226 * If *query_io is 0 to start with then any query may be returned;
227 * If *query_io is !0 adns_query then only that query may be returned.
228 * If the call is successful, *query_io, *answer_r, and *context_r
231 * Return values are 0 or an errno value;
232 * Seriously fatal system errors (eg, failure to create sockets,
233 * malloc failure, etc.) return errno values;
234 * Other errors (nameserver failure, timed out connections, &c)
235 * are returned in the status field of the answer. If status is
236 * nonzero then nrrs will be 0, otherwise it will be >0.
237 * type will always be the type requested;
238 * If no (appropriate) requests are done adns_check returns EWOULDBLOCK;
239 * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH;
242 int adns_init(adns_state
*newstate_r
, adns_initflags flags
,
243 FILE *diagfile
/*0=>stderr*/);
245 int adns_init_strcfg(adns_state
*newstate_r
, adns_initflags flags
,
246 FILE *diagfile
/*0=>discard*/, const char *configtext
);
248 int adns_synchronous(adns_state ads
,
251 adns_queryflags flags
,
252 adns_answer
**answer_r
);
254 /* NB: if you set adns_if_noautosys then _submit and _check do not
255 * make any system calls; you must use adns_callback (possibly after
256 * adns_interest) to actually get things to happen.
259 int adns_submit(adns_state ads
,
262 adns_queryflags flags
,
264 adns_query
*query_r
);
266 int adns_check(adns_state ads
,
267 adns_query
*query_io
,
268 adns_answer
**answer_r
,
271 int adns_wait(adns_state ads
,
272 adns_query
*query_io
,
273 adns_answer
**answer_r
,
275 /* fixme: minor cache */
277 void adns_cancel(adns_query query
);
279 void adns_finish(adns_state
);
280 /* You may call this even if you have queries outstanding;
281 * they will be cancelled.
284 int adns_callback(adns_state
, int maxfd
, const fd_set
*readfds
, const fd_set
*writefds
,
285 const fd_set
*exceptfds
);
286 /* Gives adns flow-of-control for a bit. This will never block.
287 * If maxfd == -1 then adns will check (make nonblocking system calls on)
288 * all of its own filedescriptors; otherwise it will only use those
289 * < maxfd and specified in the fd_set's, as if select had returned them.
290 * Other fd's may be in the fd_sets, and will be ignored.
291 * _callback returns how many adns fd's were in the various sets, so
292 * you can tell if your select handling code has missed something and is going awol.
294 * May also return -1 if a critical syscall failed, setting errno.
297 void adns_interest(adns_state
, int *maxfd_io
, fd_set
*readfds_io
,
298 fd_set
*writefds_io
, fd_set
*exceptfds_io
,
299 struct timeval
**tv_mod
, struct timeval
*tv_buf
);
300 /* Find out file descriptors adns is interested in, and when it
301 * would like the opportunity to time something out. If you do not plan to
302 * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning
303 * you have no timeout of your own, in which case tv_buf must be non-null and
304 * _interest may fill it in and set *tv_mod=tv_buf.
305 * readfds, writefds, exceptfds and maxfd may not be 0.
308 /* Example expected/legal calling sequences:
314 * adns_check 3 -> EWOULDBLOCK
320 * adns_init _noautosys
326 * adns_submit / adns_check
331 adns_status
adns_rr_info(adns_rrtype type
,
332 const char **rrtname_r
, const char **fmtname_r
,
334 const void *datap
, char **data_r
);
335 /* Gets information in human-readable (but non-i18n) form
336 * for eg debugging purposes. type must be specified,
337 * and the official name of the corresponding RR type will
338 * be returned in *rrtname_r, and information about the processing
339 * style in *fmtname_r. The length of the table entry in an answer
340 * for that type will be returned in in *len_r.
341 * Any or all of rrtname_r, fmtname_r and len_r may be 0.
342 * If fmtname_r is non-null then *fmtname_r may be
343 * null on return, indicating that no special processing is
346 * data_r be must be non-null iff datap is. In this case
347 * *data_r will be set to point to a human-readable text
348 * string representing the RR data. The text will have
349 * been obtained from malloc() and must be freed by the caller.
351 * Usually this routine will succeed. Possible errors include:
353 * adns_s_rrtypeunknown
354 * adns_s_invaliddata (*datap contained garbage)
355 * If an error occurs then no memory has been allocated,
356 * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined.
359 const char *adns_strerror(adns_status st
);