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__
101 } consistency_checks;
113 adns__qf_addr_answer= 0x01000000,/* addr query received an answer */
114 adns__qf_addr_cname = 0x02000000 /* addr subquery performed on cname */
117 /* Shared data structures */
129 int dglen, nsstart, nscount, arcount;
133 #define MAXREVLABELS 34 /* keep in sync with addrfam! */
134 struct revparse_state {
135 uint16_t labstart[MAXREVLABELS];
136 uint8_t lablen[MAXREVLABELS];
139 union checklabel_state {
140 struct revparse_state ptr;
145 void (*callback)(adns_query parent, adns_query child);
149 adns_rrtype rev_rrtype;
155 } tinfo; /* type-specific state for the query itself: zero-init if you
156 * don't know better. */
159 adns_rr_hostaddr *hostaddr;
160 } pinfo; /* state for use by parent's callback function */
163 typedef struct typeinfo {
169 void (*makefinal)(adns_query qu, void *data);
170 /* Change memory management of *data.
171 * Previously, used alloc_interim, now use alloc_final.
174 adns_status (*convstring)(vbuf *vb, adns_rrtype, const void *data);
175 /* Converts the RR data to a string representation in vbuf.
176 * vbuf will be appended to (it must have been initialised),
177 * and will not be null-terminated by convstring.
180 adns_status (*parse)(const parseinfo *pai, int cbyte,
181 int max, void *store_r);
182 /* Parse one RR, in dgram of length dglen, starting at cbyte and
183 * extending until at most max.
185 * The RR should be stored at *store_r, of length qu->typei->getrrsz().
187 * If there is an overrun which might indicate truncation, it should set
188 * *rdstart to -1; otherwise it may set it to anything else positive.
190 * nsstart is the offset of the authority section.
193 int (*diff_needswap)(adns_state ads,const void *datap_a,const void *datap_b);
194 /* Returns !0 if RR a should be strictly after RR b in the sort order,
195 * 0 otherwise. Must not fail.
198 adns_status (*checklabel)(adns_state ads, adns_queryflags flags,
199 union checklabel_state *cls, qcontext *ctx,
200 int labnum, const char *dgram,
201 int labstart, int lablen);
202 /* Check a label from the query domain string. The label is not
203 * necessarily null-terminated. The hook can refuse the query's submission
204 * by returning a nonzero status. State can be stored in *cls between
205 * calls, and useful information can be stashed in ctx->tinfo, to be stored
206 * with the query (e.g., it will be available to the parse hook). This
207 * hook can detect a first call because labnum is zero, and a final call
208 * because lablen is zero.
211 void (*postsort)(adns_state ads, void *array, int nrrs, int rrsz,
212 const struct typeinfo *typei);
213 /* Called immediately after the RRs have been sorted, and may rearrange
214 * them. (This is really for the benefit of SRV's bizarre weighting
215 * stuff.) May be 0 to mean nothing needs to be done.
218 int (*getrrsz)(const struct typeinfo *typei, adns_rrtype type);
219 /* Return the output resource-record element size; if this is null, then
220 * the rrsz member can be used.
223 void (*query_send)(adns_query qu, struct timeval now);
224 /* Send the query to nameservers, and hook it into the appropriate queue.
225 * Normal behaviour is to call adns__query_send, but this can be overridden
226 * for special effects.
230 adns_status adns__ckl_hostname(adns_state ads, adns_queryflags flags,
231 union checklabel_state *cls,
232 qcontext *ctx, int labnum,
233 const char *dgram, int labstart, int lablen);
234 /* implemented in query.c, used by types.c as default
235 * and as part of implementation for some fancier types
236 * doesn't require any state */
238 typedef struct allocnode {
239 struct allocnode *next, *back;
254 enum { query_tosend, query_tcpw, query_childw, query_done } state;
255 adns_query back, next, parent;
256 struct { adns_query head, tail; } children;
257 struct { adns_query back, next; } siblings;
258 struct { allocnode *head, *tail; } allocations;
259 int interim_allocd, preserved_allocd;
260 void *final_allocspace;
262 const typeinfo *typei;
267 /* General-purpose messing-about buffer.
268 * Wherever a `big' interface is crossed, this may be corrupted/changed
269 * unless otherwise specified.
273 /* This is allocated when a query is submitted, to avoid being unable
274 * to relate errors to queries if we run out of memory. During
275 * query processing status, rrs is 0. cname is set if
276 * we found a cname (this corresponds to cname_dgram in the query
277 * structure). type is set from the word go. nrrs and rrs
278 * are set together, when we find how many rrs there are.
279 * owner is set during querying unless we're doing searchlist,
280 * in which case it is set only when we find an answer.
284 int cname_dglen, cname_begin;
285 /* If non-0, has been allocated using . */
288 int search_origlen, search_pos, search_doneabs;
289 /* Used by the searching algorithm. The query domain in textual form
290 * is copied into the vbuf, and _origlen set to its length. Then
291 * we walk the searchlist, if we want to. _pos says where we are
292 * (next entry to try), and _doneabs says whether we've done the
293 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
294 * but not done yet). If flags doesn't have adns_qf_search then
295 * the vbuf is initialised but empty and everything else is zero.
298 int id, flags, retries;
300 unsigned long udpsent; /* bitmap indexed by server */
301 struct timeval timeout;
302 time_t expires; /* Earliest expiry time of any record we used. */
308 * state Queue child id nextudpserver udpsent tcpfailed
310 * tosend NONE null >=0 0 zero zero
311 * tosend udpw null >=0 any nonzero zero
312 * tosend NONE null >=0 any nonzero zero
314 * tcpw tcpw null >=0 irrelevant any any
316 * child childw set >=0 irrelevant irrelevant irrelevant
317 * child NONE null >=0 irrelevant irrelevant irrelevant
318 * done output null -1 irrelevant irrelevant irrelevant
320 * Queries are only not on a queue when they are actually being processed.
321 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
322 * iff the tcp connection is in state server_ok.
324 * Internal queries (from adns__submit_internal) end up on intdone
325 * instead of output, and the callbacks are made on the way out of
326 * adns, to avoid reentrancy hazards.
328 * +------------------------+
329 * START -----> | tosend/NONE |
330 * +------------------------+
332 * too big for UDP / UDP timeout \ \ send via UDP
333 * send via TCP / more retries \ \
334 * when conn'd / desired \ \
337 * +-----------+ +-------------+
338 * | tcpw/tcpw | ________ | tosend/udpw |
339 * +-----------+ \ +-------------+
340 * | | | UDP timeout | |
343 * \ | TCP died | desired | |
345 * \ \ servers | TCP / |
346 * \ \ to try | timeout / |
348 * reply \ _| +------------------+ / reply
349 * \ | done/output FAIL | /
350 * \ +------------------+ /
353 * (..... got reply ....)
355 * need child query/ies / \ no child query
358 * +---------------+ +----------------+
359 * | childw/childw | ----------------> | done/output OK |
360 * +---------------+ children done +----------------+
364 struct query_queue { adns_query head, tail; };
369 adns_initflags iflags;
370 adns_logcallbackfn *logfn;
373 struct query_queue udpw, tcpw, childw, output, intdone;
374 adns_query forallnext;
377 struct udpsocket { int af; int fd; } udpsockets[MAXUDP];
379 vbuf tcpsend, tcprecv;
380 int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
381 enum adns__tcpstate {
382 server_disconnected, server_connecting,
383 server_ok, server_broken
385 struct timeval tcptimeout;
386 /* This will have tv_sec==0 if it is not valid. It will always be
387 * valid if tcpstate _connecting. When _ok, it will be nonzero if
388 * we are idle (ie, tcpw queue is empty), in which case it is the
389 * absolute time when we will close the connection.
391 struct sigaction stdsigpipe;
393 struct pollfd pollfds_buf[MAX_POLLFDS];
394 adns_rr_addr servers[MAXSERVERS];
396 adns_sockaddr base, mask;
397 } sortlist[MAXSORTLIST];
399 unsigned config_report_unknown:1;
400 unsigned short rand48xsubi[3];
403 /* From addrfam.c: */
405 extern int adns__addrs_equal_raw(const struct sockaddr *a,
406 int bf, const void *b);
407 /* Returns nonzero a's family is bf and a's protocol address field
408 * refers to the same protocol address as that stored at ba.
411 extern int adns__addrs_equal(const adns_sockaddr *a,
412 const adns_sockaddr *b);
413 /* Returns nonzero if the two refer to the same protocol address
414 * (disregarding port, IPv6 scope, etc).
417 extern int adns__sockaddrs_equal(const struct sockaddr *sa,
418 const struct sockaddr *sb);
419 /* Return nonzero if the two socket addresses are equal (in all significant
423 extern int adns__addr_width(int af);
424 /* Return the width of addresses of family af, in bits. */
426 extern void adns__prefix_mask(adns_sockaddr *sa, int len);
427 /* Stores in sa's protocol address field an address mask for address
428 * family af, whose first len bits are set and the remainder are
429 * clear. On entry, sa's af field must be set. This is what you want
430 * for converting a prefix length into a netmask.
433 extern int adns__guess_prefix_length(const adns_sockaddr *addr);
434 /* Given a network base address, guess the appropriate prefix length based on
435 * the appropriate rules for the address family (e.g., for IPv4, this uses
436 * the old address classes).
439 extern int adns__addr_matches(int af, const void *addr,
440 const adns_sockaddr *base,
441 const adns_sockaddr *mask);
442 /* Return nonzero if the protocol address specified by af and addr
443 * lies within the network specified by base and mask.
446 extern void adns__addr_inject(const void *a, adns_sockaddr *sa);
447 /* Injects the protocol address *a into the socket adress sa. Assumes
448 * that sa->sa_family is already set correctly.
451 extern const void *adns__sockaddr_addr(const struct sockaddr *sa);
452 /* Returns the address of the protocol address field in sa.
455 char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf);
456 /* Converts sa to a string, and writes it to buf, which must be at
457 * least ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Returns buf;
461 extern int adns__make_reverse_domain(const struct sockaddr *sa,
463 char **buf_io, size_t bufsz,
465 /* Construct a reverse domain string, given a socket address and a parent
466 * zone. If zone is null, then use the standard reverse-lookup zone for the
467 * address family. If the length of the resulting string is no larger than
468 * bufsz, then the result is stored starting at *buf_io; otherwise a new
469 * buffer is allocated is used, and a pointer to it is stored in both *buf_io
470 * and *buf_free_r (the latter of which should be null on entry). If
471 * something goes wrong, then an errno value is returned: ENOSYS if the
472 * address family of sa isn't recognized, or ENOMEM if the attempt to
473 * allocate an output buffer failed.
476 extern bool adns__revparse_label(struct revparse_state *rps, int labnum,
478 int labstart, int lablen);
479 /* Parse a label in a reverse-domain name, given its index labnum (starting
480 * from zero), a pointer to its contents (which need not be null-terminated),
481 * and its length. The state in *rps is initialized implicitly when labnum
484 * Returns 1 if the parse is proceeding successfully, 0 if the domain
485 * name is definitely invalid and the parse must be abandoned.
488 extern bool adns__revparse_done(struct revparse_state *rps,
489 const char *dgram, int nlabels,
490 adns_rrtype *rrtype_r, adns_sockaddr *addr_r);
491 /* Finishes parsing a reverse-domain name, given the total number of
492 * labels in the name. On success, fills in the af and protocol
493 * address in *addr_r, and the forward query type in *rrtype_r
494 * (because that turns out to be useful). Returns 1 if the parse
500 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
502 /* From general.c: */
504 void adns__vlprintf(adns_state ads, const char *fmt, va_list al);
505 void adns__lprintf(adns_state ads, const char *fmt,
506 ...) PRINTFFORMAT(2,3);
508 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
509 int serv, adns_query qu, const char *fmt, va_list al);
511 void adns__debug(adns_state ads, int serv, adns_query qu,
512 const char *fmt, ...) PRINTFFORMAT(4,5);
513 void adns__warn(adns_state ads, int serv, adns_query qu,
514 const char *fmt, ...) PRINTFFORMAT(4,5);
515 void adns__diag(adns_state ads, int serv, adns_query qu,
516 const char *fmt, ...) PRINTFFORMAT(4,5);
518 int adns__vbuf_ensure(vbuf *vb, int want);
519 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */
520 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
521 /* 1=>success, 0=>realloc failed */
522 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
523 void adns__vbuf_init(vbuf *vb);
524 void adns__vbuf_free(vbuf *vb);
526 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
528 const byte *dgram, int dglen, int cbyte);
529 /* Unpicks a domain in a datagram and returns a string suitable for
530 * printing it as. Never fails - if an error occurs, it will
531 * return some kind of string describing the error.
533 * serv may be -1 and qu may be 0. vb must have been initialised,
534 * and will be left in an arbitrary consistent state.
536 * Returns either vb->buf, or a pointer to a string literal. Do not modify
537 * vb before using the return value.
540 int adns__getrrsz_default(const typeinfo *typei, adns_rrtype type);
541 /* Default function for the `getrrsz' type hook; returns the `fixed_rrsz'
542 * value from the typeinfo entry.
545 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
546 int (*needswap)(void *context, const void *a, const void *b),
548 /* Does an insertion sort of array which must contain nobjs objects
549 * each sz bytes long. tempbuf must point to a buffer at least
550 * sz bytes long. needswap should return !0 if a>b (strictly, ie
551 * wrong order) 0 if a<=b (ie, order is fine).
554 void adns__sigpipe_protect(adns_state);
555 void adns__sigpipe_unprotect(adns_state);
556 /* If SIGPIPE protection is not disabled, will block all signals except
557 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
558 * Each call to _protect must be followed by a call to _unprotect before
559 * any significant amount of code gets to run, since the old signal mask
560 * is stored in the adns structure.
563 /* From transmit.c: */
565 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
566 const char *owner, int ol,
567 const typeinfo *typei, adns_rrtype type,
568 adns_queryflags flags);
569 /* Assembles a query packet in vb. A new id is allocated and returned.
572 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
573 const byte *qd_dgram, int qd_dglen,
575 adns_rrtype type, adns_queryflags flags);
576 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
577 * That domain must be correct and untruncated.
580 void adns__querysend_tcp(adns_query qu, struct timeval now);
581 /* Query must be in state tcpw/tcpw; it will be sent if possible and
582 * no further processing can be done on it for now. The connection
583 * might be broken, but no reconnect will be attempted.
586 struct udpsocket *adns__udpsocket_by_af(adns_state ads, int af);
587 /* Find the UDP socket structure in ads which has the given address family.
588 * Return null if there isn't one.
590 * This is used during initialization, so ads is only partially filled in.
591 * The requirements are that nudp is set, and that udpsocket[i].af are
592 * defined for 0<=i<nudp.
595 void adns__query_send(adns_query qu, struct timeval now);
596 /* Query must be in state tosend/NONE; it will be moved to a new state,
597 * and no further processing can be done on it for now.
598 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
599 * connected), tcpsent/timew, child/childw or done/output.)
600 * __query_send may decide to use either UDP or TCP depending whether
601 * _qf_usevc is set (or has become set) and whether the query is too
607 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
609 const typeinfo *typei, adns_rrtype type,
610 vbuf *qumsg_vb, int id,
611 adns_queryflags flags, struct timeval now,
613 /* Submits a query (for internal use, called during external submits).
615 * The new query is returned in *query_r, or we return adns_s_nomemory.
617 * The query datagram should already have been assembled in qumsg_vb;
618 * the memory for it is _taken over_ by this routine whether it
619 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
621 * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo
622 * field may be modified by type hooks.
624 * When the child query is done, ctx->callback will be called. The
625 * child will already have been taken off both the global list of
626 * queries in ads and the list of children in the parent. The child
627 * will be freed when the callback returns. The parent will have been
628 * taken off the global childw queue.
630 * The callback should either call adns__query_done, if it is
631 * complete, or adns__query_fail, if an error has occurred, in which
632 * case the other children (if any) will be cancelled. If the parent
633 * has more unfinished children (or has just submitted more) then the
634 * callback may choose to wait for them - it must then put the parent
635 * back on the childw queue.
638 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
639 /* Walks down the searchlist for a query with adns_qf_search.
640 * The query should have just had a negative response, or not had
641 * any queries sent yet, and should not be on any queue.
642 * The query_dgram if any will be freed and forgotten and a new
643 * one constructed from the search_* members of the query.
645 * Cannot fail (in case of error, calls adns__query_fail).
648 void *adns__alloc_interim(adns_query qu, size_t sz);
649 void *adns__alloc_preserved(adns_query qu, size_t sz);
650 /* Allocates some memory, and records which query it came from
651 * and how much there was.
653 * If an error occurs in the query, all the memory from _interim is
654 * simply freed. If the query succeeds, one large buffer will be made
655 * which is big enough for all these allocations, and then
656 * adns__alloc_final will get memory from this buffer.
658 * _alloc_interim can fail (and return 0).
659 * The caller must ensure that the query is failed.
661 * The memory from _preserved is is kept and transferred into the
662 * larger buffer - unless we run out of memory, in which case it too
663 * is freed. When you use _preserved you have to add code to the
664 * x_nomem error exit case in adns__makefinal_query to clear out the
665 * pointers you made to those allocations, because that's when they're
666 * thrown away; you should also make a note in the declaration of
667 * those pointer variables, to note that they are _preserved rather
668 * than _interim. If they're in the answer, note it here:
669 * answer->cname and answer->owner are _preserved.
672 void adns__transfer_interim(adns_query from, adns_query to, void *block);
673 /* Transfers an interim allocation from one query to another, so that
674 * the `to' query will have room for the data when we get to makefinal
675 * and so that the free will happen when the `to' query is freed
676 * rather than the `from' query.
678 * It is legal to call adns__transfer_interim with a null pointer; this
681 * _transfer_interim also ensures that the expiry time of the `to' query
682 * is no later than that of the `from' query, so that child queries'
683 * TTLs get inherited by their parents.
686 void adns__free_interim(adns_query qu, void *p);
687 /* Forget about a block allocated by adns__alloc_interim.
690 void *adns__alloc_mine(adns_query qu, size_t sz);
691 /* Like _interim, but does not record the length for later
692 * copying into the answer. This just ensures that the memory
693 * will be freed when we're done with the query.
696 void *adns__alloc_final(adns_query qu, size_t sz);
697 /* Cannot fail, and cannot return 0.
700 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
701 void adns__makefinal_str(adns_query qu, char **strp);
703 void adns__reset_preserved(adns_query qu);
704 /* Resets all of the memory management stuff etc. to take account of
705 * only the _preserved stuff from _alloc_preserved. Used when we find
706 * an error somewhere and want to just report the error (with perhaps
707 * CNAME, owner, etc. info), and also when we're halfway through RRs
708 * in a datagram and discover that we need to retry the query.
711 void adns__cancel(adns_query qu);
712 void adns__query_done(adns_query qu);
713 void adns__query_fail(adns_query qu, adns_status st);
714 void adns__cancel_children(adns_query qu);
716 void adns__returning(adns_state ads, adns_query qu);
717 /* Must be called before returning from adns any time that we have
718 * progressed (including made, finished or destroyed) queries.
720 * Might reenter adns via internal query callbacks, so
721 * external-faciing functions which call adns__returning should
722 * normally be avoided in internal code. */
724 void adns__intdone_process(adns_state ads);
728 void adns__procdgram(adns_state ads, const byte *dgram, int len,
729 int serv, int viatcp, struct timeval now);
730 /* This function is allowed to cause new datagrams to be constructed
731 * and sent, or even new queries to be started. However,
732 * query-sending functions are not allowed to call any general event
733 * loop functions in case they accidentally call this.
735 * Ie, receiving functions may call sending functions.
736 * Sending functions may NOT call receiving functions.
741 const typeinfo *adns__findtype(adns_rrtype type);
750 int dglen, max, cbyte, namelen;
754 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
755 int serv, adns_query qu,
756 const byte *dgram, int dglen, int max,
757 int dmbegin, int *dmend_rlater);
758 /* Finds labels in a domain in a datagram.
760 * Call this routine first.
761 * dmend_rlater may be null. ads (and of course fls) may not be.
762 * serv may be -1, qu may be null - they are for error reporting.
765 adns_status adns__findlabel_next(findlabel_state *fls,
766 int *lablen_r, int *labstart_r);
767 /* Then, call this one repeatedly.
769 * It will return adns_s_ok if all is well, and tell you the length
770 * and start of successive labels. labstart_r may be null, but
771 * lablen_r must not be.
773 * After the last label, it will return with *lablen_r zero.
774 * Do not then call it again; instead, just throw away the findlabel_state.
776 * *dmend_rlater will have been set to point to the next part of
777 * the datagram after the label (or after the uncompressed part,
778 * if compression was used). *namelen_rlater will have been set
779 * to the length of the domain name (total length of labels plus
780 * 1 for each intervening dot).
782 * If the datagram appears to be truncated, *lablen_r will be -1.
783 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
784 * Do not call _next again.
786 * There may also be errors, in which case *dmend_rlater,
787 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
788 * Do not then call findlabel_next again.
795 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
796 vbuf *vb, parsedomain_flags flags,
797 const byte *dgram, int dglen, int *cbyte_io,
799 /* vb must already have been initialised; it will be reset if necessary.
800 * If there is truncation, vb->used will be set to 0; otherwise
801 * (if there is no error) vb will be null-terminated.
802 * If there is an error vb and *cbyte_io may be left indeterminate.
804 * serv may be -1 and qu may be 0 - they are used for error reporting only.
807 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
808 adns_query qu, vbuf *vb,
809 parsedomain_flags flags,
811 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
812 * for continuing an existing domain or some such of some kind. Also, unlike
813 * _parse_domain, the domain data will be appended to vb, rather than replacing
814 * the existing contents.
817 adns_status adns__findrr(adns_query qu, int serv,
818 const byte *dgram, int dglen, int *cbyte_io,
819 int *type_r, int *class_r, unsigned long *ttl_r,
820 int *rdlen_r, int *rdstart_r,
821 int *ownermatchedquery_r);
822 /* Finds the extent and some of the contents of an RR in a datagram
823 * and does some checks. The datagram is *dgram, length dglen, and
824 * the RR starts at *cbyte_io (which is updated afterwards to point
825 * to the end of the RR).
827 * The type, class, TTL and RRdata length and start are returned iff
828 * the corresponding pointer variables are not null. type_r, class_r
829 * and ttl_r may not be null. The TTL will be capped.
831 * If ownermatchedquery_r != 0 then the owner domain of this
832 * RR will be compared with that in the query (or, if the query
833 * has gone to a CNAME lookup, with the canonical name).
834 * In this case, *ownermatchedquery_r will be set to 0 or 1.
835 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
837 * If there is truncation then *type_r will be set to -1 and
838 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
841 * qu must obviously be non-null.
843 * If an error is returned then *type_r will be undefined too.
846 adns_status adns__findrr_anychk(adns_query qu, int serv,
847 const byte *dgram, int dglen, int *cbyte_io,
848 int *type_r, int *class_r,
849 unsigned long *ttl_r,
850 int *rdlen_r, int *rdstart_r,
851 const byte *eo_dgram, int eo_dglen,
852 int eo_cbyte, int *eo_matched_r);
853 /* Like adns__findrr_checked, except that the datagram and
854 * owner to compare with can be specified explicitly.
856 * If the caller thinks they know what the owner of the RR ought to
857 * be they can pass in details in eo_*: this is another (or perhaps
858 * the same datagram), and a pointer to where the putative owner
859 * starts in that datagram. In this case *eo_matched_r will be set
860 * to 1 if the datagram matched or 0 if it did not. Either
861 * both eo_dgram and eo_matched_r must both be non-null, or they
862 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
863 * The eo datagram and contained owner domain MUST be valid and
867 void adns__update_expires(adns_query qu, unsigned long ttl,
869 /* Updates the `expires' field in the query, so that it doesn't exceed
873 bool adns__labels_equal(const byte *a, int al, const byte *b, int bl);
877 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
878 /* what and why may be both 0, or both non-0. */
880 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
882 void adns__autosys(adns_state ads, struct timeval now);
883 /* Make all the system calls we want to if the application wants us to.
884 * Must not be called from within adns internal processing functions,
885 * lest we end up in recursive descent !
888 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
889 struct timeval *tv_buf);
890 /* Call with care - might reentrantly cause queries to be completed! */
892 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
893 void adns__fdevents(adns_state ads,
894 const struct pollfd *pollfds, int npollfds,
895 int maxfd, const fd_set *readfds,
896 const fd_set *writefds, const fd_set *exceptfds,
897 struct timeval now, int *r_r);
898 int adns__internal_check(adns_state ads,
899 adns_query *query_io,
900 adns_answer **answer,
903 void adns__timeouts(adns_state ads, int act,
904 struct timeval **tv_io, struct timeval *tvbuf,
906 /* If act is !0, then this will also deal with the TCP connection
907 * if previous events broke it or require it to be connected.
912 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
914 /* Useful static inline functions: */
916 static inline int ctype_whitespace(int c) {
917 return c==' ' || c=='\n' || c=='\t';
919 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
920 static inline int ctype_alpha(int c) {
921 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
923 static inline int ctype_toupper(int c) {
924 return ctype_alpha(c) ? (c & ~32) : c;
926 static inline int ctype_822special(int c) {
927 return strchr("()<>@,;:\\\".[]",c) != 0;
929 static inline int ctype_domainunquoted(int c) {
930 return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
933 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
937 #define MEM_ROUND(sz) \
938 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
939 * sizeof(union maxalign) )
941 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ffu)
942 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
943 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
944 #define GET_L(cb,tv) ( (tv)=0, \
945 (tv)|=(GETIL_B((cb))<<24), \
946 (tv)|=(GETIL_B((cb))<<16), \
947 (tv)|=(GETIL_B((cb))<<8), \