xref: /reactos/sdk/lib/3rdparty/adns/src/internal.h (revision c2c66aff)
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
9  *    Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
10  *
11  *  It is part of adns, which is
12  *    Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
13  *    Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
14  *
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.
24  *
25  *  You should have received a copy of the GNU General Public License
26  *  along with this program; if not, write to the Free Software Foundation,
27  *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
28  */
29 
30 #ifndef ADNS_INTERNAL_H_INCLUDED
31 #define ADNS_INTERNAL_H_INCLUDED
32 
33 #include "config.h"
34 
35 #ifndef ADNS_JGAA_WIN32
36 typedef unsigned char byte;
37 #endif
38 
39 
40 #include <stdarg.h>
41 #include <assert.h>
42 
43 #ifndef ADNS_JGAA_WIN32
44 # include <unistd.h>
45 #endif
46 #include <signal.h>
47 #include <errno.h>
48 #include <string.h>
49 
50 #ifndef ADNS_JGAA_WIN32
51 #  include <sys/time.h>
52 #endif
53 
54 #include "adns.h"
55 #include "dlist.h"
56 
57 #ifdef ADNS_REGRESS_TEST
58 # include "hredirect.h"
59 #endif
60 
61 /* Configuration and constants */
62 
63 #define MAXSERVERS 5
64 #define MAXSORTLIST 15
65 #define UDPMAXRETRIES 15
66 #define UDPRETRYMS 2000
67 #define TCPWAITMS 30000
68 #define TCPCONNMS 14000
69 #define TCPIDLEMS 30000
70 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
71 
72 #define DNS_PORT 53
73 #define DNS_MAXUDP 512
74 #define DNS_MAXLABEL 63
75 #define DNS_MAXDOMAIN 255
76 #define DNS_HDRSIZE 12
77 #define DNS_IDOFFSET 0
78 #define DNS_CLASS_IN 1
79 
80 #define DNS_INADDR_ARPA "in-addr", "arpa"
81 
82 #define MAX_POLLFDS  ADNS_POLLFDS_RECOMMENDED
83 
84 typedef enum {
85   cc_user,
86   cc_entex,
87   cc_freq
88 } consistency_checks;
89 
90 typedef enum {
91   rcode_noerror,
92   rcode_formaterror,
93   rcode_servfail,
94   rcode_nxdomain,
95   rcode_notimp,
96   rcode_refused
97 } dns_rcode;
98 
99 /* Shared data structures */
100 
101 typedef union {
102   adns_status status;
103   char *cp;
104   adns_rrtype type;
105   int i;
106   struct in_addr ia;
107   unsigned long ul;
108 } rr_align;
109 
110 typedef struct {
111   int used, avail;
112   byte *buf;
113 } vbuf;
114 
115 typedef struct {
116   adns_state ads;
117   adns_query qu;
118   int serv;
119   const byte *dgram;
120   int dglen, nsstart, nscount, arcount;
121   struct timeval now;
122 } parseinfo;
123 
124 typedef struct {
125   adns_rrtype type;
126   const char *rrtname;
127   const char *fmtname;
128   int rrsz;
129 
130   void (*makefinal)(adns_query qu, void *data);
131   /* Change memory management of *data.
132    * Previously, used alloc_interim, now use alloc_final.
133    */
134 
135   adns_status (*convstring)(vbuf *vb, const void *data);
136   /* Converts the RR data to a string representation in vbuf.
137    * vbuf will be appended to (it must have been initialised),
138    * and will not be null-terminated by convstring.
139    */
140 
141   adns_status (*parse)(const parseinfo *pai, int cbyte, int max, void *store_r);
142   /* Parse one RR, in dgram of length dglen, starting at cbyte and
143    * extending until at most max.
144    *
145    * The RR should be stored at *store_r, of length qu->typei->rrsz.
146    *
147    * If there is an overrun which might indicate truncation, it should set
148    * *rdstart to -1; otherwise it may set it to anything else positive.
149    *
150    * nsstart is the offset of the authority section.
151    */
152 
153   int (*diff_needswap)(adns_state ads, const void *datap_a, const void *datap_b);
154   /* Returns !0 if RR a should be strictly after RR b in the sort order,
155    * 0 otherwise.  Must not fail.
156    */
157 } typeinfo;
158 
159 typedef struct allocnode {
160   struct allocnode *next, *back;
161 } allocnode;
162 
163 union maxalign {
164   byte d[1];
165   struct in_addr ia;
166   long l;
167   void *p;
168   void (*fp)(void);
169   union maxalign *up;
170 };
171 
172 typedef struct {
173   void *ext;
174   void (*callback)(adns_query parent, adns_query child);
175   union {
176     adns_rr_addr ptr_parent_addr;
177     adns_rr_hostaddr *hostaddr;
178   } info;
179 } qcontext;
180 
181 struct adns__query {
182   adns_state ads;
183   enum { query_tosend, query_tcpw, query_childw, query_done } state;
184   adns_query back, next, parent;
185   struct { adns_query head, tail; } children;
186   struct { adns_query back, next; } siblings;
187   struct { allocnode *head, *tail; } allocations;
188   int interim_allocd, preserved_allocd;
189   void *final_allocspace;
190 
191   const typeinfo *typei;
192   byte *query_dgram;
193   int query_dglen;
194 
195   vbuf vb;
196   /* General-purpose messing-about buffer.
197    * Wherever a `big' interface is crossed, this may be corrupted/changed
198    * unless otherwise specified.
199    */
200 
201   adns_answer *answer;
202   /* This is allocated when a query is submitted, to avoid being unable
203    * to relate errors to queries if we run out of memory.  During
204    * query processing status, rrs is 0.  cname is set if
205    * we found a cname (this corresponds to cname_dgram in the query
206    * structure).  type is set from the word go.  nrrs and rrs
207    * are set together, when we find how many rrs there are.
208    * owner is set during querying unless we're doing searchlist,
209    * in which case it is set only when we find an answer.
210    */
211 
212   byte *cname_dgram;
213   int cname_dglen, cname_begin;
214   /* If non-0, has been allocated using . */
215 
216   vbuf search_vb;
217   int search_origlen, search_pos, search_doneabs;
218   /* Used by the searching algorithm.  The query domain in textual form
219    * is copied into the vbuf, and _origlen set to its length.  Then
220    * we walk the searchlist, if we want to.  _pos says where we are
221    * (next entry to try), and _doneabs says whether we've done the
222    * absolute query yet (0=not yet, 1=done, -1=must do straight away,
223    * but not done yet).  If flags doesn't have adns_qf_search then
224    * the vbuf is initialised but empty and everything else is zero.
225    */
226 
227   int id, flags, retries;
228   int udpnextserver;
229   unsigned long udpsent; /* bitmap indexed by server */
230   struct timeval timeout;
231   time_t expires; /* Earliest expiry time of any record we used. */
232 
233   qcontext ctx;
234 
235   /* Possible states:
236    *
237    *  state   Queue   child  id   nextudpserver  udpsent     tcpfailed
238    *
239    *  tosend  NONE    null   >=0  0              zero        zero
240    *  tosend  udpw    null   >=0  any            nonzero     zero
241    *  tosend  NONE    null   >=0  any            nonzero     zero
242    *
243    *  tcpw    tcpw    null   >=0  irrelevant     any         any
244    *
245    *  child   childw  set    >=0  irrelevant     irrelevant  irrelevant
246    *  child   NONE    null   >=0  irrelevant     irrelevant  irrelevant
247    *  done    output  null   -1   irrelevant     irrelevant  irrelevant
248    *
249    * Queries are only not on a queue when they are actually being processed.
250    * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
251    * iff the tcp connection is in state server_ok.
252    *
253    *			      +------------------------+
254    *             START -----> |      tosend/NONE       |
255    *			      +------------------------+
256    *                         /                       |\  \
257    *        too big for UDP /             UDP timeout  \  \ send via UDP
258    *        send via TCP   /              more retries  \  \
259    *        when conn'd   /                  desired     \  \
260    *                     |     	       	       	       	  |  |
261    *                     v				  |  v
262    *              +-----------+         	    	+-------------+
263    *              | tcpw/tcpw | ________                | tosend/udpw |
264    *              +-----------+         \	    	+-------------+
265    *                 |    |              |     UDP timeout | |
266    *                 |    |              |      no more    | |
267    *                 |    |              |      retries    | |
268    *                  \   | TCP died     |      desired    | |
269    *                   \   \ no more     |                 | |
270    *                    \   \ servers    | TCP            /  |
271    *                     \   \ to try    | timeout       /   |
272    *                  got \   \          v             |_    | got
273    *                 reply \   _| +------------------+      / reply
274    *   	       	       	    \  	  | done/output FAIL |     /
275    *                         \    +------------------+    /
276    *                          \                          /
277    *                           _|                      |_
278    *                             (..... got reply ....)
279    *                              /                   \
280    *        need child query/ies /                     \ no child query
281    *                            /                       \
282    *                          |_                         _|
283    *		   +---------------+		       +----------------+
284    *               | childw/childw | ----------------> | done/output OK |
285    *               +---------------+  children done    +----------------+
286    */
287 };
288 
289 struct query_queue { adns_query head, tail; };
290 
291 struct adns__state {
292   adns_initflags iflags;
293   FILE *diagfile;
294   int configerrno;
295   struct query_queue udpw, tcpw, childw, output;
296   adns_query forallnext;
297   int nextid;
298   ADNS_SOCKET udpsocket, tcpsocket;
299   vbuf tcpsend, tcprecv;
300   int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
301   enum adns__tcpstate {
302     server_disconnected, server_connecting,
303     server_ok, server_broken
304   } tcpstate;
305   struct timeval tcptimeout;
306   /* This will have tv_sec==0 if it is not valid.  It will always be
307    * valid if tcpstate _connecting.  When _ok, it will be nonzero if
308    * we are idle (ie, tcpw queue is empty), in which case it is the
309    * absolute time when we will close the connection.
310    */
311 #ifndef ADNS_JGAA_WIN32
312   struct sigaction stdsigpipe;
313   sigset_t stdsigmask;
314 #endif
315   struct pollfd pollfds_buf[MAX_POLLFDS];
316   struct server {
317     struct in_addr addr;
318   } servers[MAXSERVERS];
319   struct sortlist {
320     struct in_addr base, mask;
321   } sortlist[MAXSORTLIST];
322   char **searchlist;
323 };
324 
325 /* From setup.c: */
326 
327 int adns__setnonblock(adns_state ads, ADNS_SOCKET fd); /* => errno value */
328 
329 /* From general.c: */
330 
331 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
332 		 int serv, adns_query qu, const char *fmt, va_list al);
333 
334 void adns__debug(adns_state ads, int serv, adns_query qu,
335 		 const char *fmt, ...) PRINTFFORMAT(4,5);
336 void adns__warn(adns_state ads, int serv, adns_query qu,
337 		const char *fmt, ...) PRINTFFORMAT(4,5);
338 void adns__diag(adns_state ads, int serv, adns_query qu,
339 		const char *fmt, ...) PRINTFFORMAT(4,5);
340 
341 int adns__vbuf_ensure(vbuf *vb, int want);
342 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
343 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
344 /* 1=>success, 0=>realloc failed */
345 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
346 void adns__vbuf_init(vbuf *vb);
347 void adns__vbuf_free(vbuf *vb);
348 
349 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
350 			      vbuf *vb, const byte *dgram, int dglen, int cbyte);
351 /* Unpicks a domain in a datagram and returns a string suitable for
352  * printing it as.  Never fails - if an error occurs, it will
353  * return some kind of string describing the error.
354  *
355  * serv may be -1 and qu may be 0.  vb must have been initialised,
356  * and will be left in an arbitrary consistent state.
357  *
358  * Returns either vb->buf, or a pointer to a string literal.  Do not modify
359  * vb before using the return value.
360  */
361 
362 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
363 		 int (*needswap)(void *context, const void *a, const void *b),
364 		 void *context);
365 /* Does an insertion sort of array which must contain nobjs objects
366  * each sz bytes long.  tempbuf must point to a buffer at least
367  * sz bytes long.  needswap should return !0 if a>b (strictly, ie
368  * wrong order) 0 if a<=b (ie, order is fine).
369  */
370 
371 void adns__sigpipe_protect(adns_state);
372 void adns__sigpipe_unprotect(adns_state);
373 /* If SIGPIPE protection is not disabled, will block all signals except
374  * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN.  (And then restore.)
375  * Each call to _protect must be followed by a call to _unprotect before
376  * any significant amount of code gets to run, since the old signal mask
377  * is stored in the adns structure.
378  */
379 
380 /* From transmit.c: */
381 
382 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
383 			  const char *owner, int ol,
384 			  const typeinfo *typei, adns_queryflags flags);
385 /* Assembles a query packet in vb.  A new id is allocated and returned.
386  */
387 
388 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
389 				  const byte *qd_dgram, int qd_dglen, int qd_begin,
390 				  adns_rrtype type, adns_queryflags flags);
391 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
392  * That domain must be correct and untruncated.
393  */
394 
395 void adns__querysend_tcp(adns_query qu, struct timeval now);
396 /* Query must be in state tcpw/tcpw; it will be sent if possible and
397  * no further processing can be done on it for now.  The connection
398  * might be broken, but no reconnect will be attempted.
399  */
400 
401 void adns__query_send(adns_query qu, struct timeval now);
402 /* Query must be in state tosend/NONE; it will be moved to a new state,
403  * and no further processing can be done on it for now.
404  * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
405  *  tcpsent/timew, child/childw or done/output.)
406  * __query_send may decide to use either UDP or TCP depending whether
407  * _qf_usevc is set (or has become set) and whether the query is too
408  * large.
409  */
410 
411 /* From query.c: */
412 
413 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
414 				  const typeinfo *typei, vbuf *qumsg_vb, int id,
415 				  adns_queryflags flags, struct timeval now,
416 				  const qcontext *ctx);
417 /* Submits a query (for internal use, called during external submits).
418  *
419  * The new query is returned in *query_r, or we return adns_s_nomemory.
420  *
421  * The query datagram should already have been assembled in qumsg_vb;
422  * the memory for it is _taken over_ by this routine whether it
423  * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
424  *
425  * *ctx is copied byte-for-byte into the query.
426  *
427  * When the child query is done, ctx->callback will be called.  The
428  * child will already have been taken off both the global list of
429  * queries in ads and the list of children in the parent.  The child
430  * will be freed when the callback returns.  The parent will have been
431  * taken off the global childw queue.
432  *
433  * The callback should either call adns__query_done, if it is
434  * complete, or adns__query_fail, if an error has occurred, in which
435  * case the other children (if any) will be cancelled.  If the parent
436  * has more unfinished children (or has just submitted more) then the
437  * callback may choose to wait for them - it must then put the parent
438  * back on the childw queue.
439  */
440 
441 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
442 /* Walks down the searchlist for a query with adns_qf_search.
443  * The query should have just had a negative response, or not had
444  * any queries sent yet, and should not be on any queue.
445  * The query_dgram if any will be freed and forgotten and a new
446  * one constructed from the search_* members of the query.
447  *
448  * Cannot fail (in case of error, calls adns__query_fail).
449  */
450 
451 void *adns__alloc_interim(adns_query qu, size_t sz);
452 void *adns__alloc_preserved(adns_query qu, size_t sz);
453 /* Allocates some memory, and records which query it came from
454  * and how much there was.
455  *
456  * If an error occurs in the query, all the memory from _interim is
457  * simply freed.  If the query succeeds, one large buffer will be made
458  * which is big enough for all these allocations, and then
459  * adns__alloc_final will get memory from this buffer.
460  *
461  * _alloc_interim can fail (and return 0).
462  * The caller must ensure that the query is failed.
463  *
464  * The memory from _preserved is is kept and transferred into the
465  * larger buffer - unless we run out of memory, in which case it too
466  * is freed.  When you use _preserved you have to add code to the
467  * x_nomem error exit case in adns__makefinal_query to clear out the
468  * pointers you made to those allocations, because that's when they're
469  * thrown away; you should also make a note in the declaration of
470  * those pointer variables, to note that they are _preserved rather
471  * than _interim.  If they're in the answer, note it here:
472  *  answer->cname and answer->owner are _preserved.
473  */
474 
475 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
476 /* Transfers an interim allocation from one query to another, so that
477  * the `to' query will have room for the data when we get to makefinal
478  * and so that the free will happen when the `to' query is freed
479  * rather than the `from' query.
480  *
481  * It is legal to call adns__transfer_interim with a null pointer; this
482  * has no effect.
483  *
484  * _transfer_interim also ensures that the expiry time of the `to' query
485  * is no later than that of the `from' query, so that child queries'
486  * TTLs get inherited by their parents.
487  */
488 
489 void *adns__alloc_mine(adns_query qu, size_t sz);
490 /* Like _interim, but does not record the length for later
491  * copying into the answer.  This just ensures that the memory
492  * will be freed when we're done with the query.
493  */
494 
495 void *adns__alloc_final(adns_query qu, size_t sz);
496 /* Cannot fail, and cannot return 0.
497  */
498 
499 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
500 void adns__makefinal_str(adns_query qu, char **strp);
501 
502 void adns__reset_preserved(adns_query qu);
503 /* Resets all of the memory management stuff etc. to take account of
504  * only the _preserved stuff from _alloc_preserved.  Used when we find
505  * an error somewhere and want to just report the error (with perhaps
506  * CNAME, owner, etc. info), and also when we're halfway through RRs
507  * in a datagram and discover that we need to retry the query.
508  */
509 
510 void adns__query_done(adns_query qu);
511 void adns__query_fail(adns_query qu, adns_status stat);
512 
513 /* From reply.c: */
514 
515 void adns__procdgram(adns_state ads, const byte *dgram, int len,
516 		     int serv, int viatcp, struct timeval now);
517 /* This function is allowed to cause new datagrams to be constructed
518  * and sent, or even new queries to be started.  However,
519  * query-sending functions are not allowed to call any general event
520  * loop functions in case they accidentally call this.
521  *
522  * Ie, receiving functions may call sending functions.
523  * Sending functions may NOT call receiving functions.
524  */
525 
526 /* From types.c: */
527 
528 const typeinfo *adns__findtype(adns_rrtype type);
529 
530 /* From parse.c: */
531 
532 typedef struct {
533   adns_state ads;
534   adns_query qu;
535   int serv;
536   const byte *dgram;
537   int dglen, max, cbyte, namelen;
538   int *dmend_r;
539 } findlabel_state;
540 
541 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
542 			   int serv, adns_query qu,
543 			   const byte *dgram, int dglen, int max,
544 			   int dmbegin, int *dmend_rlater);
545 /* Finds labels in a domain in a datagram.
546  *
547  * Call this routine first.
548  * dmend_rlater may be null.  ads (and of course fls) may not be.
549  * serv may be -1, qu may be null - they are for error reporting.
550  */
551 
552 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
553 /* Then, call this one repeatedly.
554  *
555  * It will return adns_s_ok if all is well, and tell you the length
556  * and start of successive labels.  labstart_r may be null, but
557  * lablen_r must not be.
558  *
559  * After the last label, it will return with *lablen_r zero.
560  * Do not then call it again; instead, just throw away the findlabel_state.
561  *
562  * *dmend_rlater will have been set to point to the next part of
563  * the datagram after the label (or after the uncompressed part,
564  * if compression was used).  *namelen_rlater will have been set
565  * to the length of the domain name (total length of labels plus
566  * 1 for each intervening dot).
567  *
568  * If the datagram appears to be truncated, *lablen_r will be -1.
569  * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
570  * Do not call _next again.
571  *
572  * There may also be errors, in which case *dmend_rlater,
573  * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
574  * Do not then call findlabel_next again.
575  */
576 
577 typedef enum {
578   pdf_quoteok= 0x001
579 } parsedomain_flags;
580 
581 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
582 			       vbuf *vb, adns_queryflags flags,
583 			       const byte *dgram, int dglen, int *cbyte_io, int max);
584 /* vb must already have been initialised; it will be reset if necessary.
585  * If there is truncation, vb->used will be set to 0; otherwise
586  * (if there is no error) vb will be null-terminated.
587  * If there is an error vb and *cbyte_io may be left indeterminate.
588  *
589  * serv may be -1 and qu may be 0 - they are used for error reporting only.
590  */
591 
592 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
593 				    adns_query qu, vbuf *vb, parsedomain_flags flags,
594 				    const byte *dgram);
595 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
596  * for continuing an existing domain or some such of some kind.  Also, unlike
597  * _parse_domain, the domain data will be appended to vb, rather than replacing
598  * the existing contents.
599  */
600 
601 adns_status adns__findrr(adns_query qu, int serv,
602 			 const byte *dgram, int dglen, int *cbyte_io,
603 			 int *type_r, int *class_r, unsigned long *ttl_r,
604 			 int *rdlen_r, int *rdstart_r,
605 			 int *ownermatchedquery_r);
606 /* Finds the extent and some of the contents of an RR in a datagram
607  * and does some checks.  The datagram is *dgram, length dglen, and
608  * the RR starts at *cbyte_io (which is updated afterwards to point
609  * to the end of the RR).
610  *
611  * The type, class, TTL and RRdata length and start are returned iff
612  * the corresponding pointer variables are not null.  type_r, class_r
613  * and ttl_r may not be null.  The TTL will be capped.
614  *
615  * If ownermatchedquery_r != 0 then the owner domain of this
616  * RR will be compared with that in the query (or, if the query
617  * has gone to a CNAME lookup, with the canonical name).
618  * In this case, *ownermatchedquery_r will be set to 0 or 1.
619  * The query datagram (or CNAME datagram) MUST be valid and not truncated.
620  *
621  * If there is truncation then *type_r will be set to -1 and
622  * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
623  * undefined.
624  *
625  * qu must obviously be non-null.
626  *
627  * If an error is returned then *type_r will be undefined too.
628  */
629 
630 adns_status adns__findrr_anychk(adns_query qu, int serv,
631 				const byte *dgram, int dglen, int *cbyte_io,
632 				int *type_r, int *class_r, unsigned long *ttl_r,
633 				int *rdlen_r, int *rdstart_r,
634 				const byte *eo_dgram, int eo_dglen, int eo_cbyte,
635 				int *eo_matched_r);
636 /* Like adns__findrr_checked, except that the datagram and
637  * owner to compare with can be specified explicitly.
638  *
639  * If the caller thinks they know what the owner of the RR ought to
640  * be they can pass in details in eo_*: this is another (or perhaps
641  * the same datagram), and a pointer to where the putative owner
642  * starts in that datagram.  In this case *eo_matched_r will be set
643  * to 1 if the datagram matched or 0 if it did not.  Either
644  * both eo_dgram and eo_matched_r must both be non-null, or they
645  * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
646  * The eo datagram and contained owner domain MUST be valid and
647  * untruncated.
648  */
649 
650 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now);
651 /* Updates the `expires' field in the query, so that it doesn't exceed
652  * now + ttl.
653  */
654 
655 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
656 
657 /* From event.c: */
658 
659 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
660 /* what and why may be both 0, or both non-0. */
661 
662 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
663 
664 void adns__autosys(adns_state ads, struct timeval now);
665 /* Make all the system calls we want to if the application wants us to.
666  * Must not be called from within adns internal processing functions,
667  * lest we end up in recursive descent !
668  */
669 
670 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
671 			     struct timeval *tv_buf);
672 
673 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
674 void adns__fdevents(adns_state ads,
675 		    const struct pollfd *pollfds, int npollfds,
676 		    int maxfd, const fd_set *readfds,
677 		    const fd_set *writefds, const fd_set *exceptfds,
678 		    struct timeval now, int *r_r);
679 int adns__internal_check(adns_state ads,
680 			 adns_query *query_io,
681 			 adns_answer **answer,
682 			 void **context_r);
683 
684 void adns__timeouts(adns_state ads, int act,
685 		    struct timeval **tv_io, struct timeval *tvbuf,
686 		    struct timeval now);
687 /* If act is !0, then this will also deal with the TCP connection
688  * if previous events broke it or require it to be connected.
689  */
690 
691 /* From check.c: */
692 
693 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
694 
695 /* Useful static inline functions: */
696 
ctype_whitespace(int c)697 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
ctype_digit(int c)698 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
ctype_alpha(int c)699 static inline int ctype_alpha(int c) {
700   return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
701 }
ctype_822special(int c)702 static inline int ctype_822special(int c) { return strchr("()<>@,;:\\\".[]",c) != 0; }
ctype_domainunquoted(int c)703 static inline int ctype_domainunquoted(int c) {
704   return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
705 }
706 
errno_resources(int e)707 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
708 
709 /* Useful macros */
710 
711 #define MEM_ROUND(sz) \
712   (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
713    * sizeof(union maxalign) )
714 
715 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
716 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
717 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
718 #define GET_L(cb,tv) ( (tv)=0, \
719 		       (tv)|=(GETIL_B((cb))<<24), \
720 		       (tv)|=(GETIL_B((cb))<<16), \
721 		       (tv)|=(GETIL_B((cb))<<8), \
722 		       (tv)|=GETIL_B(cb), \
723 		       (tv) )
724 
725 #endif
726