3 * - declarations of private objects with external linkage (adns__*)
4 * - definitons of internal macros
5 * - comments regarding library data structures
8 * This file is part of adns, which is
9 * Copyright (C) 1997-2000,2003,2006,2014-2016 Ian Jackson
10 * Copyright (C) 2014 Mark Wooding
11 * Copyright (C) 1999-2000,2003,2006 Tony Finch
12 * Copyright (C) 1991 Massachusetts Institute of Technology
13 * (See the file INSTALL for full details.)
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 3, or (at your option)
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.
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.
29 #ifndef ADNS_INTERNAL_H_INCLUDED
30 #define ADNS_INTERNAL_H_INCLUDED
33 typedef unsigned char byte;
46 #define ADNS_FEATURE_MANYAF
50 #ifdef ADNS_REGRESS_TEST
51 # include "hredirect.h"
54 /* Configuration and constants */
56 #define MAXSERVERS 5 /* do not increase beyond no. of bits in `unsigned'! */
57 #define MAXSORTLIST 15
58 #define UDPMAXRETRIES 15
59 #define UDPRETRYMS 2000
60 #define TCPWAITMS 30000
61 #define TCPCONNMS 14000
62 #define TCPIDLEMS 30000
63 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
66 #define DNS_MAXUDP 512
67 #define DNS_MAXLABEL 63
68 #define DNS_MAXDOMAIN 255
69 #define DNS_HDRSIZE 12
70 #define DNS_IDOFFSET 0
71 #define DNS_CLASS_IN 1
73 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
75 /* Some preprocessor hackery */
77 #define GLUE(x, y) GLUE_(x, y)
78 #define GLUE_(x, y) x##y
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
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
94 #define CDR_m(_, ...) __VA_ARGS__
100 } consistency_checks;
112 adns__qf_addr_answer= 0x01000000,/* addr query received an answer */
113 adns__qf_addr_cname = 0x02000000 /* addr subquery performed on cname */
116 /* Shared data structures */
128 int dglen, nsstart, nscount, arcount;
132 #define MAXREVLABELS 34 /* keep in sync with addrfam! */
133 struct revparse_state {
134 uint16_t labstart[MAXREVLABELS];
135 uint8_t lablen[MAXREVLABELS];
138 union checklabel_state {
139 struct revparse_state ptr;
144 void (*callback)(adns_query parent, adns_query child);
148 adns_rrtype rev_rrtype;
154 } tinfo; /* type-specific state for the query itself: zero-init if you
155 * don't know better. */
158 adns_rr_hostaddr *hostaddr;
159 } pinfo; /* state for use by parent's callback function */
162 typedef struct typeinfo {
168 void (*makefinal)(adns_query qu, void *data);
169 /* Change memory management of *data.
170 * Previously, used alloc_interim, now use alloc_final.
173 adns_status (*convstring)(vbuf *vb, adns_rrtype, const void *data);
174 /* Converts the RR data to a string representation in vbuf.
175 * vbuf will be appended to (it must have been initialised),
176 * and will not be null-terminated by convstring.
179 adns_status (*parse)(const parseinfo *pai, int cbyte,
180 int max, void *store_r);
181 /* Parse one RR, in dgram of length dglen, starting at cbyte and
182 * extending until at most max.
184 * The RR should be stored at *store_r, of length qu->typei->getrrsz().
186 * If there is an overrun which might indicate truncation, it should set
187 * *rdstart to -1; otherwise it may set it to anything else positive.
189 * nsstart is the offset of the authority section.
192 int (*diff_needswap)(adns_state ads,const void *datap_a,const void *datap_b);
193 /* Returns !0 if RR a should be strictly after RR b in the sort order,
194 * 0 otherwise. Must not fail.
197 adns_status (*checklabel)(adns_state ads, adns_queryflags flags,
198 union checklabel_state *cls, qcontext *ctx,
199 int labnum, const char *dgram,
200 int labstart, int lablen);
201 /* Check a label from the query domain string. The label is not
202 * necessarily null-terminated. The hook can refuse the query's submission
203 * by returning a nonzero status. State can be stored in *cls between
204 * calls, and useful information can be stashed in ctx->tinfo, to be stored
205 * with the query (e.g., it will be available to the parse hook). This
206 * hook can detect a first call because labnum is zero, and a final call
207 * because lablen is zero.
210 void (*postsort)(adns_state ads, void *array, int nrrs, int rrsz,
211 const struct typeinfo *typei);
212 /* Called immediately after the RRs have been sorted, and may rearrange
213 * them. (This is really for the benefit of SRV's bizarre weighting
214 * stuff.) May be 0 to mean nothing needs to be done.
217 int (*getrrsz)(const struct typeinfo *typei, adns_rrtype type);
218 /* Return the output resource-record element size; if this is null, then
219 * the rrsz member can be used.
222 void (*query_send)(adns_query qu, struct timeval now);
223 /* Send the query to nameservers, and hook it into the appropriate queue.
224 * Normal behaviour is to call adns__query_send, but this can be overridden
225 * for special effects.
229 adns_status adns__ckl_hostname(adns_state ads, adns_queryflags flags,
230 union checklabel_state *cls,
231 qcontext *ctx, int labnum,
232 const char *dgram, int labstart, int lablen);
233 /* implemented in query.c, used by types.c as default
234 * and as part of implementation for some fancier types
235 * doesn't require any state */
237 typedef struct allocnode {
238 struct allocnode *next, *back;
253 enum { query_tosend, query_tcpw, query_childw, query_done } state;
254 adns_query back, next, parent;
255 struct { adns_query head, tail; } children;
256 struct { adns_query back, next; } siblings;
257 struct { allocnode *head, *tail; } allocations;
258 int interim_allocd, preserved_allocd;
259 void *final_allocspace;
261 const typeinfo *typei;
266 /* General-purpose messing-about buffer.
267 * Wherever a `big' interface is crossed, this may be corrupted/changed
268 * unless otherwise specified.
272 /* This is allocated when a query is submitted, to avoid being unable
273 * to relate errors to queries if we run out of memory. During
274 * query processing status, rrs is 0. cname is set if
275 * we found a cname (this corresponds to cname_dgram in the query
276 * structure). type is set from the word go. nrrs and rrs
277 * are set together, when we find how many rrs there are.
278 * owner is set during querying unless we're doing searchlist,
279 * in which case it is set only when we find an answer.
283 int cname_dglen, cname_begin;
284 /* If non-0, has been allocated using . */
287 int search_origlen, search_pos, search_doneabs;
288 /* Used by the searching algorithm. The query domain in textual form
289 * is copied into the vbuf, and _origlen set to its length. Then
290 * we walk the searchlist, if we want to. _pos says where we are
291 * (next entry to try), and _doneabs says whether we've done the
292 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
293 * but not done yet). If flags doesn't have adns_qf_search then
294 * the vbuf is initialised but empty and everything else is zero.
297 int id, flags, retries;
299 unsigned long udpsent; /* bitmap indexed by server */
300 struct timeval timeout;
301 time_t expires; /* Earliest expiry time of any record we used. */
307 * state Queue child id nextudpserver udpsent tcpfailed
309 * tosend NONE null >=0 0 zero zero
310 * tosend udpw null >=0 any nonzero zero
311 * tosend NONE null >=0 any nonzero zero
313 * tcpw tcpw null >=0 irrelevant any any
315 * child childw set >=0 irrelevant irrelevant irrelevant
316 * child NONE null >=0 irrelevant irrelevant irrelevant
317 * done output null -1 irrelevant irrelevant irrelevant
319 * Queries are only not on a queue when they are actually being processed.
320 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
321 * iff the tcp connection is in state server_ok.
323 * Internal queries (from adns__submit_internal) end up on intdone
324 * instead of output, and the callbacks are made on the way out of
325 * adns, to avoid reentrancy hazards.
327 * +------------------------+
328 * START -----> | tosend/NONE |
329 * +------------------------+
331 * too big for UDP / UDP timeout \ \ send via UDP
332 * send via TCP / more retries \ \
333 * when conn'd / desired \ \
336 * +-----------+ +-------------+
337 * | tcpw/tcpw | ________ | tosend/udpw |
338 * +-----------+ \ +-------------+
339 * | | | UDP timeout | |
342 * \ | TCP died | desired | |
344 * \ \ servers | TCP / |
345 * \ \ to try | timeout / |
347 * reply \ _| +------------------+ / reply
348 * \ | done/output FAIL | /
349 * \ +------------------+ /
352 * (..... got reply ....)
354 * need child query/ies / \ no child query
357 * +---------------+ +----------------+
358 * | childw/childw | ----------------> | done/output OK |
359 * +---------------+ children done +----------------+
363 struct query_queue { adns_query head, tail; };
368 adns_initflags iflags;
369 adns_logcallbackfn *logfn;
372 struct query_queue udpw, tcpw, childw, output, intdone;
373 adns_query forallnext;
376 struct udpsocket { int af; int fd; } udpsockets[MAXUDP];
378 vbuf tcpsend, tcprecv;
379 int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
380 enum adns__tcpstate {
381 server_disconnected, server_connecting,
382 server_ok, server_broken
384 struct timeval tcptimeout;
385 /* This will have tv_sec==0 if it is not valid. It will always be
386 * valid if tcpstate _connecting. When _ok, it will be nonzero if
387 * we are idle (ie, tcpw queue is empty), in which case it is the
388 * absolute time when we will close the connection.
390 struct sigaction stdsigpipe;
392 struct pollfd pollfds_buf[MAX_POLLFDS];
393 adns_rr_addr servers[MAXSERVERS];
395 adns_sockaddr base, mask;
396 } sortlist[MAXSORTLIST];
398 unsigned config_report_unknown:1;
399 unsigned short rand48xsubi[3];
402 /* From addrfam.c: */
404 extern int adns__addrs_equal_raw(const struct sockaddr *a,
405 int bf, const void *b);
406 /* Returns nonzero a's family is bf and a's protocol address field
407 * refers to the same protocol address as that stored at ba.
410 extern int adns__addrs_equal(const adns_sockaddr *a,
411 const adns_sockaddr *b);
412 /* Returns nonzero if the two refer to the same protocol address
413 * (disregarding port, IPv6 scope, etc).
416 extern int adns__sockaddrs_equal(const struct sockaddr *sa,
417 const struct sockaddr *sb);
418 /* Return nonzero if the two socket addresses are equal (in all significant
422 extern int adns__addr_width(int af);
423 /* Return the width of addresses of family af, in bits. */
425 extern void adns__prefix_mask(adns_sockaddr *sa, int len);
426 /* Stores in sa's protocol address field an address mask for address
427 * family af, whose first len bits are set and the remainder are
428 * clear. On entry, sa's af field must be set. This is what you want
429 * for converting a prefix length into a netmask.
432 extern int adns__guess_prefix_length(const adns_sockaddr *addr);
433 /* Given a network base address, guess the appropriate prefix length based on
434 * the appropriate rules for the address family (e.g., for IPv4, this uses
435 * the old address classes).
438 extern int adns__addr_matches(int af, const void *addr,
439 const adns_sockaddr *base,
440 const adns_sockaddr *mask);
441 /* Return nonzero if the protocol address specified by af and addr
442 * lies within the network specified by base and mask.
445 extern void adns__addr_inject(const void *a, adns_sockaddr *sa);
446 /* Injects the protocol address *a into the socket adress sa. Assumes
447 * that sa->sa_family is already set correctly.
450 extern const void *adns__sockaddr_addr(const struct sockaddr *sa);
451 /* Returns the address of the protocol address field in sa.
454 char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf);
455 /* Converts sa to a string, and writes it to buf, which must be at
456 * least ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Returns buf;
460 extern int adns__make_reverse_domain(const struct sockaddr *sa,
462 char **buf_io, size_t bufsz,
464 /* Construct a reverse domain string, given a socket address and a parent
465 * zone. If zone is null, then use the standard reverse-lookup zone for the
466 * address family. If the length of the resulting string is no larger than
467 * bufsz, then the result is stored starting at *buf_io; otherwise a new
468 * buffer is allocated is used, and a pointer to it is stored in both *buf_io
469 * and *buf_free_r (the latter of which should be null on entry). If
470 * something goes wrong, then an errno value is returned: ENOSYS if the
471 * address family of sa isn't recognized, or ENOMEM if the attempt to
472 * allocate an output buffer failed.
475 extern bool adns__revparse_label(struct revparse_state *rps, int labnum,
477 int labstart, int lablen);
478 /* Parse a label in a reverse-domain name, given its index labnum (starting
479 * from zero), a pointer to its contents (which need not be null-terminated),
480 * and its length. The state in *rps is initialized implicitly when labnum
483 * Returns 1 if the parse is proceeding successfully, 0 if the domain
484 * name is definitely invalid and the parse must be abandoned.
487 extern bool adns__revparse_done(struct revparse_state *rps,
488 const char *dgram, int nlabels,
489 adns_rrtype *rrtype_r, adns_sockaddr *addr_r);
490 /* Finishes parsing a reverse-domain name, given the total number of
491 * labels in the name. On success, fills in the af and protocol
492 * address in *addr_r, and the forward query type in *rrtype_r
493 * (because that turns out to be useful). Returns 1 if the parse
499 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
501 /* From general.c: */
503 void adns__vlprintf(adns_state ads, const char *fmt, va_list al);
504 void adns__lprintf(adns_state ads, const char *fmt,
505 ...) PRINTFFORMAT(2,3);
507 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
508 int serv, adns_query qu, const char *fmt, va_list al);
510 void adns__debug(adns_state ads, int serv, adns_query qu,
511 const char *fmt, ...) PRINTFFORMAT(4,5);
512 void adns__warn(adns_state ads, int serv, adns_query qu,
513 const char *fmt, ...) PRINTFFORMAT(4,5);
514 void adns__diag(adns_state ads, int serv, adns_query qu,
515 const char *fmt, ...) PRINTFFORMAT(4,5);
517 int adns__vbuf_ensure(vbuf *vb, int want);
518 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */
519 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
520 /* 1=>success, 0=>realloc failed */
521 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
522 void adns__vbuf_init(vbuf *vb);
523 void adns__vbuf_free(vbuf *vb);
525 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
527 const byte *dgram, int dglen, int cbyte);
528 /* Unpicks a domain in a datagram and returns a string suitable for
529 * printing it as. Never fails - if an error occurs, it will
530 * return some kind of string describing the error.
532 * serv may be -1 and qu may be 0. vb must have been initialised,
533 * and will be left in an arbitrary consistent state.
535 * Returns either vb->buf, or a pointer to a string literal. Do not modify
536 * vb before using the return value.
539 int adns__getrrsz_default(const typeinfo *typei, adns_rrtype type);
540 /* Default function for the `getrrsz' type hook; returns the `fixed_rrsz'
541 * value from the typeinfo entry.
544 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
545 int (*needswap)(void *context, const void *a, const void *b),
547 /* Does an insertion sort of array which must contain nobjs objects
548 * each sz bytes long. tempbuf must point to a buffer at least
549 * sz bytes long. needswap should return !0 if a>b (strictly, ie
550 * wrong order) 0 if a<=b (ie, order is fine).
553 void adns__sigpipe_protect(adns_state);
554 void adns__sigpipe_unprotect(adns_state);
555 /* If SIGPIPE protection is not disabled, will block all signals except
556 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
557 * Each call to _protect must be followed by a call to _unprotect before
558 * any significant amount of code gets to run, since the old signal mask
559 * is stored in the adns structure.
562 /* From transmit.c: */
564 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
565 const char *owner, int ol,
566 const typeinfo *typei, adns_rrtype type,
567 adns_queryflags flags);
568 /* Assembles a query packet in vb. A new id is allocated and returned.
571 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
572 const byte *qd_dgram, int qd_dglen,
574 adns_rrtype type, adns_queryflags flags);
575 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
576 * That domain must be correct and untruncated.
579 void adns__querysend_tcp(adns_query qu, struct timeval now);
580 /* Query must be in state tcpw/tcpw; it will be sent if possible and
581 * no further processing can be done on it for now. The connection
582 * might be broken, but no reconnect will be attempted.
585 struct udpsocket *adns__udpsocket_by_af(adns_state ads, int af);
586 /* Find the UDP socket structure in ads which has the given address family.
587 * Return null if there isn't one.
589 * This is used during initialization, so ads is only partially filled in.
590 * The requirements are that nudp is set, and that udpsocket[i].af are
591 * defined for 0<=i<nudp.
594 void adns__query_send(adns_query qu, struct timeval now);
595 /* Query must be in state tosend/NONE; it will be moved to a new state,
596 * and no further processing can be done on it for now.
597 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
598 * connected), tcpsent/timew, child/childw or done/output.)
599 * __query_send may decide to use either UDP or TCP depending whether
600 * _qf_usevc is set (or has become set) and whether the query is too
606 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
608 const typeinfo *typei, adns_rrtype type,
609 vbuf *qumsg_vb, int id,
610 adns_queryflags flags, struct timeval now,
612 /* Submits a query (for internal use, called during external submits).
614 * The new query is returned in *query_r, or we return adns_s_nomemory.
616 * The query datagram should already have been assembled in qumsg_vb;
617 * the memory for it is _taken over_ by this routine whether it
618 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
620 * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo
621 * field may be modified by type hooks.
623 * When the child query is done, ctx->callback will be called. The
624 * child will already have been taken off both the global list of
625 * queries in ads and the list of children in the parent. The child
626 * will be freed when the callback returns. The parent will have been
627 * taken off the global childw queue.
629 * The callback should either call adns__query_done, if it is
630 * complete, or adns__query_fail, if an error has occurred, in which
631 * case the other children (if any) will be cancelled. If the parent
632 * has more unfinished children (or has just submitted more) then the
633 * callback may choose to wait for them - it must then put the parent
634 * back on the childw queue.
637 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
638 /* Walks down the searchlist for a query with adns_qf_search.
639 * The query should have just had a negative response, or not had
640 * any queries sent yet, and should not be on any queue.
641 * The query_dgram if any will be freed and forgotten and a new
642 * one constructed from the search_* members of the query.
644 * Cannot fail (in case of error, calls adns__query_fail).
647 void *adns__alloc_interim(adns_query qu, size_t sz);
648 void *adns__alloc_preserved(adns_query qu, size_t sz);
649 /* Allocates some memory, and records which query it came from
650 * and how much there was.
652 * If an error occurs in the query, all the memory from _interim is
653 * simply freed. If the query succeeds, one large buffer will be made
654 * which is big enough for all these allocations, and then
655 * adns__alloc_final will get memory from this buffer.
657 * _alloc_interim can fail (and return 0).
658 * The caller must ensure that the query is failed.
660 * The memory from _preserved is is kept and transferred into the
661 * larger buffer - unless we run out of memory, in which case it too
662 * is freed. When you use _preserved you have to add code to the
663 * x_nomem error exit case in adns__makefinal_query to clear out the
664 * pointers you made to those allocations, because that's when they're
665 * thrown away; you should also make a note in the declaration of
666 * those pointer variables, to note that they are _preserved rather
667 * than _interim. If they're in the answer, note it here:
668 * answer->cname and answer->owner are _preserved.
671 void adns__transfer_interim(adns_query from, adns_query to, void *block);
672 /* Transfers an interim allocation from one query to another, so that
673 * the `to' query will have room for the data when we get to makefinal
674 * and so that the free will happen when the `to' query is freed
675 * rather than the `from' query.
677 * It is legal to call adns__transfer_interim with a null pointer; this
680 * _transfer_interim also ensures that the expiry time of the `to' query
681 * is no later than that of the `from' query, so that child queries'
682 * TTLs get inherited by their parents.
685 void adns__free_interim(adns_query qu, void *p);
686 /* Forget about a block allocated by adns__alloc_interim.
689 void *adns__alloc_mine(adns_query qu, size_t sz);
690 /* Like _interim, but does not record the length for later
691 * copying into the answer. This just ensures that the memory
692 * will be freed when we're done with the query.
695 void *adns__alloc_final(adns_query qu, size_t sz);
696 /* Cannot fail, and cannot return 0.
699 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
700 void adns__makefinal_str(adns_query qu, char **strp);
702 void adns__reset_preserved(adns_query qu);
703 /* Resets all of the memory management stuff etc. to take account of
704 * only the _preserved stuff from _alloc_preserved. Used when we find
705 * an error somewhere and want to just report the error (with perhaps
706 * CNAME, owner, etc. info), and also when we're halfway through RRs
707 * in a datagram and discover that we need to retry the query.
710 void adns__cancel(adns_query qu);
711 void adns__query_done(adns_query qu);
712 void adns__query_fail(adns_query qu, adns_status st);
713 void adns__cancel_children(adns_query qu);
715 void adns__returning(adns_state ads, adns_query qu);
716 /* Must be called before returning from adns any time that we have
717 * progressed (including made, finished or destroyed) queries.
719 * Might reenter adns via internal query callbacks, so
720 * external-faciing functions which call adns__returning should
721 * normally be avoided in internal code. */
723 void adns__intdone_process(adns_state ads);
727 void adns__procdgram(adns_state ads, const byte *dgram, int len,
728 int serv, int viatcp, struct timeval now);
729 /* This function is allowed to cause new datagrams to be constructed
730 * and sent, or even new queries to be started. However,
731 * query-sending functions are not allowed to call any general event
732 * loop functions in case they accidentally call this.
734 * Ie, receiving functions may call sending functions.
735 * Sending functions may NOT call receiving functions.
740 const typeinfo *adns__findtype(adns_rrtype type);
749 int dglen, max, cbyte, namelen;
753 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
754 int serv, adns_query qu,
755 const byte *dgram, int dglen, int max,
756 int dmbegin, int *dmend_rlater);
757 /* Finds labels in a domain in a datagram.
759 * Call this routine first.
760 * dmend_rlater may be null. ads (and of course fls) may not be.
761 * serv may be -1, qu may be null - they are for error reporting.
764 adns_status adns__findlabel_next(findlabel_state *fls,
765 int *lablen_r, int *labstart_r);
766 /* Then, call this one repeatedly.
768 * It will return adns_s_ok if all is well, and tell you the length
769 * and start of successive labels. labstart_r may be null, but
770 * lablen_r must not be.
772 * After the last label, it will return with *lablen_r zero.
773 * Do not then call it again; instead, just throw away the findlabel_state.
775 * *dmend_rlater will have been set to point to the next part of
776 * the datagram after the label (or after the uncompressed part,
777 * if compression was used). *namelen_rlater will have been set
778 * to the length of the domain name (total length of labels plus
779 * 1 for each intervening dot).
781 * If the datagram appears to be truncated, *lablen_r will be -1.
782 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
783 * Do not call _next again.
785 * There may also be errors, in which case *dmend_rlater,
786 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
787 * Do not then call findlabel_next again.
794 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
795 vbuf *vb, parsedomain_flags flags,
796 const byte *dgram, int dglen, int *cbyte_io,
798 /* vb must already have been initialised; it will be reset if necessary.
799 * If there is truncation, vb->used will be set to 0; otherwise
800 * (if there is no error) vb will be null-terminated.
801 * If there is an error vb and *cbyte_io may be left indeterminate.
803 * serv may be -1 and qu may be 0 - they are used for error reporting only.
806 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
807 adns_query qu, vbuf *vb,
808 parsedomain_flags flags,
810 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
811 * for continuing an existing domain or some such of some kind. Also, unlike
812 * _parse_domain, the domain data will be appended to vb, rather than replacing
813 * the existing contents.
816 adns_status adns__findrr(adns_query qu, int serv,
817 const byte *dgram, int dglen, int *cbyte_io,
818 int *type_r, int *class_r, unsigned long *ttl_r,
819 int *rdlen_r, int *rdstart_r,
820 int *ownermatchedquery_r);
821 /* Finds the extent and some of the contents of an RR in a datagram
822 * and does some checks. The datagram is *dgram, length dglen, and
823 * the RR starts at *cbyte_io (which is updated afterwards to point
824 * to the end of the RR).
826 * The type, class, TTL and RRdata length and start are returned iff
827 * the corresponding pointer variables are not null. type_r, class_r
828 * and ttl_r may not be null. The TTL will be capped.
830 * If ownermatchedquery_r != 0 then the owner domain of this
831 * RR will be compared with that in the query (or, if the query
832 * has gone to a CNAME lookup, with the canonical name).
833 * In this case, *ownermatchedquery_r will be set to 0 or 1.
834 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
836 * If there is truncation then *type_r will be set to -1 and
837 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
840 * qu must obviously be non-null.
842 * If an error is returned then *type_r will be undefined too.
845 adns_status adns__findrr_anychk(adns_query qu, int serv,
846 const byte *dgram, int dglen, int *cbyte_io,
847 int *type_r, int *class_r,
848 unsigned long *ttl_r,
849 int *rdlen_r, int *rdstart_r,
850 const byte *eo_dgram, int eo_dglen,
851 int eo_cbyte, int *eo_matched_r);
852 /* Like adns__findrr_checked, except that the datagram and
853 * owner to compare with can be specified explicitly.
855 * If the caller thinks they know what the owner of the RR ought to
856 * be they can pass in details in eo_*: this is another (or perhaps
857 * the same datagram), and a pointer to where the putative owner
858 * starts in that datagram. In this case *eo_matched_r will be set
859 * to 1 if the datagram matched or 0 if it did not. Either
860 * both eo_dgram and eo_matched_r must both be non-null, or they
861 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
862 * The eo datagram and contained owner domain MUST be valid and
866 void adns__update_expires(adns_query qu, unsigned long ttl,
868 /* Updates the `expires' field in the query, so that it doesn't exceed
872 bool adns__labels_equal(const byte *a, int al, const byte *b, int bl);
876 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
877 /* what and why may be both 0, or both non-0. */
879 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
881 void adns__autosys(adns_state ads, struct timeval now);
882 /* Make all the system calls we want to if the application wants us to.
883 * Must not be called from within adns internal processing functions,
884 * lest we end up in recursive descent !
887 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
888 struct timeval *tv_buf);
889 /* Call with care - might reentrantly cause queries to be completed! */
891 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
892 void adns__fdevents(adns_state ads,
893 const struct pollfd *pollfds, int npollfds,
894 int maxfd, const fd_set *readfds,
895 const fd_set *writefds, const fd_set *exceptfds,
896 struct timeval now, int *r_r);
897 int adns__internal_check(adns_state ads,
898 adns_query *query_io,
899 adns_answer **answer,
902 void adns__timeouts(adns_state ads, int act,
903 struct timeval **tv_io, struct timeval *tvbuf,
905 /* If act is !0, then this will also deal with the TCP connection
906 * if previous events broke it or require it to be connected.
911 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
913 /* Useful static inline functions: */
915 static inline int ctype_whitespace(int c) {
916 return c==' ' || c=='\n' || c=='\t';
918 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
919 static inline int ctype_alpha(int c) {
920 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
922 static inline int ctype_toupper(int c) {
923 return ctype_alpha(c) ? (c & ~32) : c;
925 static inline int ctype_822special(int c) {
926 return strchr("()<>@,;:\\\".[]",c) != 0;
928 static inline int ctype_domainunquoted(int c) {
929 return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
932 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
936 #define MEM_ROUND(sz) \
937 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
938 * sizeof(union maxalign) )
940 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ffu)
941 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
942 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
943 #define GET_L(cb,tv) ( (tv)=0, \
944 (tv)|=(GETIL_B((cb))<<24), \
945 (tv)|=(GETIL_B((cb))<<16), \
946 (tv)|=(GETIL_B((cb))<<8), \