38168814e8d32029beaecab2979874dffe337869
[adns] / src / internal.h
1 /*
2 * internal.h
3 * - declarations of private objects with external linkage (adns__*)
4 * - definitons of internal macros
5 * - comments regarding library data structures
6 */
7 /*
8 * This file is part of adns, which is
9 * Copyright (C) 1997-2000,2003,2006 Ian Jackson
10 * Copyright (C) 1999-2000,2003,2006 Tony Finch
11 * Copyright (C) 1991 Massachusetts Institute of Technology
12 * (See the file INSTALL for full details.)
13 *
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
17 * any later version.
18 *
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 */
28
29 #ifndef ADNS_INTERNAL_H_INCLUDED
30 #define ADNS_INTERNAL_H_INCLUDED
31
32 #include "config.h"
33 typedef unsigned char byte;
34
35 #include <stdarg.h>
36 #include <assert.h>
37 #include <unistd.h>
38 #include <signal.h>
39 #include <errno.h>
40 #include <string.h>
41 #include <stdlib.h>
42
43 #include <sys/time.h>
44
45 #include "adns.h"
46 #include "dlist.h"
47
48 #ifdef ADNS_REGRESS_TEST
49 # include "hredirect.h"
50 #endif
51
52 /* Configuration and constants */
53
54 #define MAXSERVERS 5
55 #define MAXSORTLIST 15
56 #define UDPMAXRETRIES 15
57 #define UDPRETRYMS 2000
58 #define TCPWAITMS 30000
59 #define TCPCONNMS 14000
60 #define TCPIDLEMS 30000
61 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
62
63 #define DNS_PORT 53
64 #define DNS_MAXUDP 512
65 #define DNS_MAXLABEL 63
66 #define DNS_MAXDOMAIN 255
67 #define DNS_HDRSIZE 12
68 #define DNS_IDOFFSET 0
69 #define DNS_CLASS_IN 1
70
71 #define DNS_INADDR_ARPA "in-addr", "arpa"
72
73 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
74
75 /* Some preprocessor hackery */
76
77 #define GLUE(x, y) GLUE_(x, y)
78 #define GLUE_(x, y) x##y
79
80 /* C99 macro `...' must match at least one argument, so the naive definition
81 * `#define CAR(car, ...) car' won't work. But it's easy to arrange for the
82 * tail to be nonempty if we're just going to discard it anyway. */
83 #define CAR(...) CAR_(__VA_ARGS__, _)
84 #define CAR_(car, ...) car
85
86 /* Extracting the tail of an argument list is rather more difficult. The
87 * following trick is based on one by Laurent Deniau to count the number of
88 * arguments to a macro, simplified in two ways: (a) it only handles up to
89 * eight arguments, and (b) it only needs to distinguish the one-argument
90 * case from many arguments. */
91 #define CDR(...) CDR_(__VA_ARGS__, m, m, m, m, m, m, m, 1, _)(__VA_ARGS__)
92 #define CDR_(_1, _2, _3, _4, _5, _6, _7, _8, n, ...) CDR_##n
93 #define CDR_1(_)
94 #define CDR_m(_, ...) __VA_ARGS__
95
96 typedef enum {
97 cc_user,
98 cc_entex,
99 cc_freq
100 } consistency_checks;
101
102 typedef enum {
103 rcode_noerror,
104 rcode_formaterror,
105 rcode_servfail,
106 rcode_nxdomain,
107 rcode_notimp,
108 rcode_refused
109 } dns_rcode;
110
111 /* Shared data structures */
112
113 typedef struct {
114 int used, avail;
115 byte *buf;
116 } vbuf;
117
118 typedef struct {
119 adns_state ads;
120 adns_query qu;
121 int serv;
122 const byte *dgram;
123 int dglen, nsstart, nscount, arcount;
124 struct timeval now;
125 } parseinfo;
126
127 typedef struct {
128 void *ext;
129 void (*callback)(adns_query parent, adns_query child);
130
131 union {
132 adns_rr_addr ptr_addr;
133 } tinfo; /* type-specific state for the query itself: zero-init if you
134 * don't know better. */
135
136 union {
137 adns_rr_hostaddr *hostaddr;
138 } pinfo; /* state for use by parent's callback function */
139 } qcontext;
140
141 typedef struct typeinfo {
142 adns_rrtype typekey;
143 const char *rrtname;
144 const char *fmtname;
145 int rrsz;
146
147 void (*makefinal)(adns_query qu, void *data);
148 /* Change memory management of *data.
149 * Previously, used alloc_interim, now use alloc_final.
150 */
151
152 adns_status (*convstring)(vbuf *vb, const void *data);
153 /* Converts the RR data to a string representation in vbuf.
154 * vbuf will be appended to (it must have been initialised),
155 * and will not be null-terminated by convstring.
156 */
157
158 adns_status (*parse)(const parseinfo *pai, int cbyte,
159 int max, void *store_r);
160 /* Parse one RR, in dgram of length dglen, starting at cbyte and
161 * extending until at most max.
162 *
163 * The RR should be stored at *store_r, of length qu->typei->rrsz.
164 *
165 * If there is an overrun which might indicate truncation, it should set
166 * *rdstart to -1; otherwise it may set it to anything else positive.
167 *
168 * nsstart is the offset of the authority section.
169 */
170
171 int (*diff_needswap)(adns_state ads,const void *datap_a,const void *datap_b);
172 /* Returns !0 if RR a should be strictly after RR b in the sort order,
173 * 0 otherwise. Must not fail.
174 */
175
176 adns_status (*qdparselabel)(adns_state ads,
177 const char **p_io, const char *pe, int labelnum,
178 char label_r[DNS_MAXDOMAIN], int *ll_io,
179 adns_queryflags flags,
180 const struct typeinfo *typei);
181 /* Parses one label from the query domain string. On entry, *p_io
182 * points to the next character to parse and *ll_io is the size of
183 * the buffer. pe points just after the end of the query domain
184 * string. On successful return, label_r[] and *ll_io are filled in
185 * and *p_io points to *pe or just after the label-ending `.'. */
186
187 void (*postsort)(adns_state ads, void *array, int nrrs,
188 const struct typeinfo *typei);
189 /* Called immediately after the RRs have been sorted, and may rearrange
190 * them. (This is really for the benefit of SRV's bizarre weighting
191 * stuff.) May be 0 to mean nothing needs to be done.
192 */
193 } typeinfo;
194
195 adns_status adns__qdpl_normal(adns_state ads,
196 const char **p_io, const char *pe, int labelnum,
197 char label_r[], int *ll_io,
198 adns_queryflags flags,
199 const typeinfo *typei);
200 /* implemented in transmit.c, used by types.c as default
201 * and as part of implementation for some fancier types */
202
203 typedef struct allocnode {
204 struct allocnode *next, *back;
205 } allocnode;
206
207 union maxalign {
208 byte d[1];
209 struct in_addr ia;
210 long l;
211 void *p;
212 void (*fp)(void);
213 union maxalign *up;
214 } data;
215
216 struct adns__query {
217 adns_state ads;
218 enum { query_tosend, query_tcpw, query_childw, query_done } state;
219 adns_query back, next, parent;
220 struct { adns_query head, tail; } children;
221 struct { adns_query back, next; } siblings;
222 struct { allocnode *head, *tail; } allocations;
223 int interim_allocd, preserved_allocd;
224 void *final_allocspace;
225
226 const typeinfo *typei;
227 byte *query_dgram;
228 int query_dglen;
229
230 vbuf vb;
231 /* General-purpose messing-about buffer.
232 * Wherever a `big' interface is crossed, this may be corrupted/changed
233 * unless otherwise specified.
234 */
235
236 adns_answer *answer;
237 /* This is allocated when a query is submitted, to avoid being unable
238 * to relate errors to queries if we run out of memory. During
239 * query processing status, rrs is 0. cname is set if
240 * we found a cname (this corresponds to cname_dgram in the query
241 * structure). type is set from the word go. nrrs and rrs
242 * are set together, when we find how many rrs there are.
243 * owner is set during querying unless we're doing searchlist,
244 * in which case it is set only when we find an answer.
245 */
246
247 byte *cname_dgram;
248 int cname_dglen, cname_begin;
249 /* If non-0, has been allocated using . */
250
251 vbuf search_vb;
252 int search_origlen, search_pos, search_doneabs;
253 /* Used by the searching algorithm. The query domain in textual form
254 * is copied into the vbuf, and _origlen set to its length. Then
255 * we walk the searchlist, if we want to. _pos says where we are
256 * (next entry to try), and _doneabs says whether we've done the
257 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
258 * but not done yet). If flags doesn't have adns_qf_search then
259 * the vbuf is initialised but empty and everything else is zero.
260 */
261
262 int id, flags, retries;
263 int udpnextserver;
264 unsigned long udpsent; /* bitmap indexed by server */
265 struct timeval timeout;
266 time_t expires; /* Earliest expiry time of any record we used. */
267
268 qcontext ctx;
269
270 /* Possible states:
271 *
272 * state Queue child id nextudpserver udpsent tcpfailed
273 *
274 * tosend NONE null >=0 0 zero zero
275 * tosend udpw null >=0 any nonzero zero
276 * tosend NONE null >=0 any nonzero zero
277 *
278 * tcpw tcpw null >=0 irrelevant any any
279 *
280 * child childw set >=0 irrelevant irrelevant irrelevant
281 * child NONE null >=0 irrelevant irrelevant irrelevant
282 * done output null -1 irrelevant irrelevant irrelevant
283 *
284 * Queries are only not on a queue when they are actually being processed.
285 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
286 * iff the tcp connection is in state server_ok.
287 *
288 * +------------------------+
289 * START -----> | tosend/NONE |
290 * +------------------------+
291 * / |\ \
292 * too big for UDP / UDP timeout \ \ send via UDP
293 * send via TCP / more retries \ \
294 * when conn'd / desired \ \
295 * | | |
296 * v | v
297 * +-----------+ +-------------+
298 * | tcpw/tcpw | ________ | tosend/udpw |
299 * +-----------+ \ +-------------+
300 * | | | UDP timeout | |
301 * | | | no more | |
302 * | | | retries | |
303 * \ | TCP died | desired | |
304 * \ \ no more | | |
305 * \ \ servers | TCP / |
306 * \ \ to try | timeout / |
307 * got \ \ v |_ | got
308 * reply \ _| +------------------+ / reply
309 * \ | done/output FAIL | /
310 * \ +------------------+ /
311 * \ /
312 * _| |_
313 * (..... got reply ....)
314 * / \
315 * need child query/ies / \ no child query
316 * / \
317 * |_ _|
318 * +---------------+ +----------------+
319 * | childw/childw | ----------------> | done/output OK |
320 * +---------------+ children done +----------------+
321 */
322 };
323
324 struct query_queue { adns_query head, tail; };
325
326 struct adns__state {
327 adns_initflags iflags;
328 adns_logcallbackfn *logfn;
329 void *logfndata;
330 int configerrno;
331 struct query_queue udpw, tcpw, childw, output;
332 adns_query forallnext;
333 int nextid, udpsocket, tcpsocket;
334 vbuf tcpsend, tcprecv;
335 int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
336 enum adns__tcpstate {
337 server_disconnected, server_connecting,
338 server_ok, server_broken
339 } tcpstate;
340 struct timeval tcptimeout;
341 /* This will have tv_sec==0 if it is not valid. It will always be
342 * valid if tcpstate _connecting. When _ok, it will be nonzero if
343 * we are idle (ie, tcpw queue is empty), in which case it is the
344 * absolute time when we will close the connection.
345 */
346 struct sigaction stdsigpipe;
347 sigset_t stdsigmask;
348 struct pollfd pollfds_buf[MAX_POLLFDS];
349 struct server {
350 struct in_addr addr;
351 } servers[MAXSERVERS];
352 struct sortlist {
353 struct in_addr base, mask;
354 } sortlist[MAXSORTLIST];
355 char **searchlist;
356 unsigned short rand48xsubi[3];
357 };
358
359 /* From setup.c: */
360
361 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
362
363 /* From general.c: */
364
365 void adns__vlprintf(adns_state ads, const char *fmt, va_list al);
366 void adns__lprintf(adns_state ads, const char *fmt,
367 ...) PRINTFFORMAT(2,3);
368
369 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
370 int serv, adns_query qu, const char *fmt, va_list al);
371
372 void adns__debug(adns_state ads, int serv, adns_query qu,
373 const char *fmt, ...) PRINTFFORMAT(4,5);
374 void adns__warn(adns_state ads, int serv, adns_query qu,
375 const char *fmt, ...) PRINTFFORMAT(4,5);
376 void adns__diag(adns_state ads, int serv, adns_query qu,
377 const char *fmt, ...) PRINTFFORMAT(4,5);
378
379 int adns__vbuf_ensure(vbuf *vb, int want);
380 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */
381 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
382 /* 1=>success, 0=>realloc failed */
383 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
384 void adns__vbuf_init(vbuf *vb);
385 void adns__vbuf_free(vbuf *vb);
386
387 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
388 vbuf *vb,
389 const byte *dgram, int dglen, int cbyte);
390 /* Unpicks a domain in a datagram and returns a string suitable for
391 * printing it as. Never fails - if an error occurs, it will
392 * return some kind of string describing the error.
393 *
394 * serv may be -1 and qu may be 0. vb must have been initialised,
395 * and will be left in an arbitrary consistent state.
396 *
397 * Returns either vb->buf, or a pointer to a string literal. Do not modify
398 * vb before using the return value.
399 */
400
401 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
402 int (*needswap)(void *context, const void *a, const void *b),
403 void *context);
404 /* Does an insertion sort of array which must contain nobjs objects
405 * each sz bytes long. tempbuf must point to a buffer at least
406 * sz bytes long. needswap should return !0 if a>b (strictly, ie
407 * wrong order) 0 if a<=b (ie, order is fine).
408 */
409
410 void adns__sigpipe_protect(adns_state);
411 void adns__sigpipe_unprotect(adns_state);
412 /* If SIGPIPE protection is not disabled, will block all signals except
413 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
414 * Each call to _protect must be followed by a call to _unprotect before
415 * any significant amount of code gets to run, since the old signal mask
416 * is stored in the adns structure.
417 */
418
419 /* From transmit.c: */
420
421 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
422 const char *owner, int ol,
423 const typeinfo *typei, adns_rrtype type,
424 adns_queryflags flags);
425 /* Assembles a query packet in vb. A new id is allocated and returned.
426 */
427
428 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
429 const byte *qd_dgram, int qd_dglen,
430 int qd_begin,
431 adns_rrtype type, adns_queryflags flags);
432 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
433 * That domain must be correct and untruncated.
434 */
435
436 void adns__querysend_tcp(adns_query qu, struct timeval now);
437 /* Query must be in state tcpw/tcpw; it will be sent if possible and
438 * no further processing can be done on it for now. The connection
439 * might be broken, but no reconnect will be attempted.
440 */
441
442 void adns__query_send(adns_query qu, struct timeval now);
443 /* Query must be in state tosend/NONE; it will be moved to a new state,
444 * and no further processing can be done on it for now.
445 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
446 * connected), tcpsent/timew, child/childw or done/output.)
447 * __query_send may decide to use either UDP or TCP depending whether
448 * _qf_usevc is set (or has become set) and whether the query is too
449 * large.
450 */
451
452 /* From query.c: */
453
454 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
455 const typeinfo *typei, vbuf *qumsg_vb,
456 int id,
457 adns_queryflags flags, struct timeval now,
458 qcontext *ctx);
459 /* Submits a query (for internal use, called during external submits).
460 *
461 * The new query is returned in *query_r, or we return adns_s_nomemory.
462 *
463 * The query datagram should already have been assembled in qumsg_vb;
464 * the memory for it is _taken over_ by this routine whether it
465 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
466 *
467 * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo
468 * field may be modified by type hooks.
469 *
470 * When the child query is done, ctx->callback will be called. The
471 * child will already have been taken off both the global list of
472 * queries in ads and the list of children in the parent. The child
473 * will be freed when the callback returns. The parent will have been
474 * taken off the global childw queue.
475 *
476 * The callback should either call adns__query_done, if it is
477 * complete, or adns__query_fail, if an error has occurred, in which
478 * case the other children (if any) will be cancelled. If the parent
479 * has more unfinished children (or has just submitted more) then the
480 * callback may choose to wait for them - it must then put the parent
481 * back on the childw queue.
482 */
483
484 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
485 /* Walks down the searchlist for a query with adns_qf_search.
486 * The query should have just had a negative response, or not had
487 * any queries sent yet, and should not be on any queue.
488 * The query_dgram if any will be freed and forgotten and a new
489 * one constructed from the search_* members of the query.
490 *
491 * Cannot fail (in case of error, calls adns__query_fail).
492 */
493
494 void *adns__alloc_interim(adns_query qu, size_t sz);
495 void *adns__alloc_preserved(adns_query qu, size_t sz);
496 /* Allocates some memory, and records which query it came from
497 * and how much there was.
498 *
499 * If an error occurs in the query, all the memory from _interim is
500 * simply freed. If the query succeeds, one large buffer will be made
501 * which is big enough for all these allocations, and then
502 * adns__alloc_final will get memory from this buffer.
503 *
504 * _alloc_interim can fail (and return 0).
505 * The caller must ensure that the query is failed.
506 *
507 * The memory from _preserved is is kept and transferred into the
508 * larger buffer - unless we run out of memory, in which case it too
509 * is freed. When you use _preserved you have to add code to the
510 * x_nomem error exit case in adns__makefinal_query to clear out the
511 * pointers you made to those allocations, because that's when they're
512 * thrown away; you should also make a note in the declaration of
513 * those pointer variables, to note that they are _preserved rather
514 * than _interim. If they're in the answer, note it here:
515 * answer->cname and answer->owner are _preserved.
516 */
517
518 void adns__transfer_interim(adns_query from, adns_query to,
519 void *block, size_t sz);
520 /* Transfers an interim allocation from one query to another, so that
521 * the `to' query will have room for the data when we get to makefinal
522 * and so that the free will happen when the `to' query is freed
523 * rather than the `from' query.
524 *
525 * It is legal to call adns__transfer_interim with a null pointer; this
526 * has no effect.
527 *
528 * _transfer_interim also ensures that the expiry time of the `to' query
529 * is no later than that of the `from' query, so that child queries'
530 * TTLs get inherited by their parents.
531 */
532
533 void *adns__alloc_mine(adns_query qu, size_t sz);
534 /* Like _interim, but does not record the length for later
535 * copying into the answer. This just ensures that the memory
536 * will be freed when we're done with the query.
537 */
538
539 void *adns__alloc_final(adns_query qu, size_t sz);
540 /* Cannot fail, and cannot return 0.
541 */
542
543 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
544 void adns__makefinal_str(adns_query qu, char **strp);
545
546 void adns__reset_preserved(adns_query qu);
547 /* Resets all of the memory management stuff etc. to take account of
548 * only the _preserved stuff from _alloc_preserved. Used when we find
549 * an error somewhere and want to just report the error (with perhaps
550 * CNAME, owner, etc. info), and also when we're halfway through RRs
551 * in a datagram and discover that we need to retry the query.
552 */
553
554 void adns__query_done(adns_query qu);
555 void adns__query_fail(adns_query qu, adns_status stat);
556
557 /* From reply.c: */
558
559 void adns__procdgram(adns_state ads, const byte *dgram, int len,
560 int serv, int viatcp, struct timeval now);
561 /* This function is allowed to cause new datagrams to be constructed
562 * and sent, or even new queries to be started. However,
563 * query-sending functions are not allowed to call any general event
564 * loop functions in case they accidentally call this.
565 *
566 * Ie, receiving functions may call sending functions.
567 * Sending functions may NOT call receiving functions.
568 */
569
570 /* From types.c: */
571
572 const typeinfo *adns__findtype(adns_rrtype type);
573
574 /* From parse.c: */
575
576 typedef struct {
577 adns_state ads;
578 adns_query qu;
579 int serv;
580 const byte *dgram;
581 int dglen, max, cbyte, namelen;
582 int *dmend_r;
583 } findlabel_state;
584
585 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
586 int serv, adns_query qu,
587 const byte *dgram, int dglen, int max,
588 int dmbegin, int *dmend_rlater);
589 /* Finds labels in a domain in a datagram.
590 *
591 * Call this routine first.
592 * dmend_rlater may be null. ads (and of course fls) may not be.
593 * serv may be -1, qu may be null - they are for error reporting.
594 */
595
596 adns_status adns__findlabel_next(findlabel_state *fls,
597 int *lablen_r, int *labstart_r);
598 /* Then, call this one repeatedly.
599 *
600 * It will return adns_s_ok if all is well, and tell you the length
601 * and start of successive labels. labstart_r may be null, but
602 * lablen_r must not be.
603 *
604 * After the last label, it will return with *lablen_r zero.
605 * Do not then call it again; instead, just throw away the findlabel_state.
606 *
607 * *dmend_rlater will have been set to point to the next part of
608 * the datagram after the label (or after the uncompressed part,
609 * if compression was used). *namelen_rlater will have been set
610 * to the length of the domain name (total length of labels plus
611 * 1 for each intervening dot).
612 *
613 * If the datagram appears to be truncated, *lablen_r will be -1.
614 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
615 * Do not call _next again.
616 *
617 * There may also be errors, in which case *dmend_rlater,
618 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
619 * Do not then call findlabel_next again.
620 */
621
622 typedef enum {
623 pdf_quoteok= 0x001
624 } parsedomain_flags;
625
626 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
627 vbuf *vb, parsedomain_flags flags,
628 const byte *dgram, int dglen, int *cbyte_io,
629 int max);
630 /* vb must already have been initialised; it will be reset if necessary.
631 * If there is truncation, vb->used will be set to 0; otherwise
632 * (if there is no error) vb will be null-terminated.
633 * If there is an error vb and *cbyte_io may be left indeterminate.
634 *
635 * serv may be -1 and qu may be 0 - they are used for error reporting only.
636 */
637
638 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
639 adns_query qu, vbuf *vb,
640 parsedomain_flags flags,
641 const byte *dgram);
642 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
643 * for continuing an existing domain or some such of some kind. Also, unlike
644 * _parse_domain, the domain data will be appended to vb, rather than replacing
645 * the existing contents.
646 */
647
648 adns_status adns__findrr(adns_query qu, int serv,
649 const byte *dgram, int dglen, int *cbyte_io,
650 int *type_r, int *class_r, unsigned long *ttl_r,
651 int *rdlen_r, int *rdstart_r,
652 int *ownermatchedquery_r);
653 /* Finds the extent and some of the contents of an RR in a datagram
654 * and does some checks. The datagram is *dgram, length dglen, and
655 * the RR starts at *cbyte_io (which is updated afterwards to point
656 * to the end of the RR).
657 *
658 * The type, class, TTL and RRdata length and start are returned iff
659 * the corresponding pointer variables are not null. type_r, class_r
660 * and ttl_r may not be null. The TTL will be capped.
661 *
662 * If ownermatchedquery_r != 0 then the owner domain of this
663 * RR will be compared with that in the query (or, if the query
664 * has gone to a CNAME lookup, with the canonical name).
665 * In this case, *ownermatchedquery_r will be set to 0 or 1.
666 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
667 *
668 * If there is truncation then *type_r will be set to -1 and
669 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
670 * undefined.
671 *
672 * qu must obviously be non-null.
673 *
674 * If an error is returned then *type_r will be undefined too.
675 */
676
677 adns_status adns__findrr_anychk(adns_query qu, int serv,
678 const byte *dgram, int dglen, int *cbyte_io,
679 int *type_r, int *class_r,
680 unsigned long *ttl_r,
681 int *rdlen_r, int *rdstart_r,
682 const byte *eo_dgram, int eo_dglen,
683 int eo_cbyte, int *eo_matched_r);
684 /* Like adns__findrr_checked, except that the datagram and
685 * owner to compare with can be specified explicitly.
686 *
687 * If the caller thinks they know what the owner of the RR ought to
688 * be they can pass in details in eo_*: this is another (or perhaps
689 * the same datagram), and a pointer to where the putative owner
690 * starts in that datagram. In this case *eo_matched_r will be set
691 * to 1 if the datagram matched or 0 if it did not. Either
692 * both eo_dgram and eo_matched_r must both be non-null, or they
693 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
694 * The eo datagram and contained owner domain MUST be valid and
695 * untruncated.
696 */
697
698 void adns__update_expires(adns_query qu, unsigned long ttl,
699 struct timeval now);
700 /* Updates the `expires' field in the query, so that it doesn't exceed
701 * now + ttl.
702 */
703
704 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
705
706 /* From event.c: */
707
708 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
709 /* what and why may be both 0, or both non-0. */
710
711 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
712
713 void adns__autosys(adns_state ads, struct timeval now);
714 /* Make all the system calls we want to if the application wants us to.
715 * Must not be called from within adns internal processing functions,
716 * lest we end up in recursive descent !
717 */
718
719 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
720 struct timeval *tv_buf);
721
722 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
723 void adns__fdevents(adns_state ads,
724 const struct pollfd *pollfds, int npollfds,
725 int maxfd, const fd_set *readfds,
726 const fd_set *writefds, const fd_set *exceptfds,
727 struct timeval now, int *r_r);
728 int adns__internal_check(adns_state ads,
729 adns_query *query_io,
730 adns_answer **answer,
731 void **context_r);
732
733 void adns__timeouts(adns_state ads, int act,
734 struct timeval **tv_io, struct timeval *tvbuf,
735 struct timeval now);
736 /* If act is !0, then this will also deal with the TCP connection
737 * if previous events broke it or require it to be connected.
738 */
739
740 /* From check.c: */
741
742 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
743
744 /* Useful static inline functions: */
745
746 static inline int ctype_whitespace(int c) {
747 return c==' ' || c=='\n' || c=='\t';
748 }
749 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
750 static inline int ctype_alpha(int c) {
751 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
752 }
753 static inline int ctype_822special(int c) {
754 return strchr("()<>@,;:\\\".[]",c) != 0;
755 }
756 static inline int ctype_domainunquoted(int c) {
757 return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
758 }
759
760 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
761
762 /* Useful macros */
763
764 #define MEM_ROUND(sz) \
765 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
766 * sizeof(union maxalign) )
767
768 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
769 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
770 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
771 #define GET_L(cb,tv) ( (tv)=0, \
772 (tv)|=(GETIL_B((cb))<<24), \
773 (tv)|=(GETIL_B((cb))<<16), \
774 (tv)|=(GETIL_B((cb))<<8), \
775 (tv)|=GETIL_B(cb), \
776 (tv) )
777
778 #endif