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) 1997-2000,2003,2006,2014-2016,2020 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 */
302 struct timeval timeout_started;
303 time_t expires; /* Earliest expiry time of any record we used. */
309 * state Queue child id nextudpserver udpsent tcpfailed
311 * tosend NONE null >=0 0 zero zero
312 * tosend udpw null >=0 any nonzero zero
313 * tosend NONE null >=0 any nonzero zero
315 * tcpw tcpw null >=0 irrelevant any any
317 * child childw set >=0 irrelevant irrelevant irrelevant
318 * child NONE null >=0 irrelevant irrelevant irrelevant
319 * done output null -1 irrelevant irrelevant irrelevant
321 * Queries are only not on a queue when they are actually being processed.
322 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
323 * iff the tcp connection is in state server_ok.
325 * Internal queries (from adns__submit_internal) end up on intdone
326 * instead of output, and the callbacks are made on the way out of
327 * adns, to avoid reentrancy hazards.
329 * +------------------------+
330 * START -----> | tosend/NONE |
331 * +------------------------+
333 * too big for UDP / UDP timeout \ \ send via UDP
334 * send via TCP / more retries \ \
335 * when conn'd / desired \ \
338 * +-----------+ +-------------+
339 * | tcpw/tcpw | ________ | tosend/udpw |
340 * +-----------+ \ +-------------+
341 * | | | UDP timeout | |
344 * \ | TCP died | desired | |
346 * \ \ servers | TCP / |
347 * \ \ to try | timeout / |
349 * reply \ _| +------------------+ / reply
350 * \ | done/output FAIL | /
351 * \ +------------------+ /
354 * (..... got reply ....)
356 * need child query/ies / \ no child query
359 * +---------------+ +----------------+
360 * | childw/childw | ----------------> | done/output OK |
361 * +---------------+ children done +----------------+
365 struct query_queue { adns_query head, tail; };
370 adns_initflags iflags;
371 adns_logcallbackfn *logfn;
374 struct query_queue udpw, tcpw, childw, output, intdone;
375 adns_query forallnext;
378 struct udpsocket { int af; int fd; } udpsockets[MAXUDP];
380 vbuf tcpsend, tcprecv;
381 int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
382 enum adns__tcpstate {
383 server_disconnected, server_connecting,
384 server_ok, server_broken
386 struct timeval tcptimeout;
387 /* This will have tv_sec==0 if it is not valid. It will always be
388 * valid if tcpstate _connecting. When _ok, it will be nonzero if
389 * we are idle (ie, tcpw queue is empty), in which case it is the
390 * absolute time when we will close the connection.
392 struct sigaction stdsigpipe;
394 struct pollfd pollfds_buf[MAX_POLLFDS];
395 adns_rr_addr servers[MAXSERVERS];
397 adns_sockaddr base, mask;
398 } sortlist[MAXSORTLIST];
400 unsigned config_report_unknown:1;
401 unsigned short rand48xsubi[3];
404 /* From addrfam.c: */
406 extern int adns__addrs_equal_raw(const struct sockaddr *a,
407 int bf, const void *b);
408 /* Returns nonzero a's family is bf and a's protocol address field
409 * refers to the same protocol address as that stored at ba.
412 extern int adns__addrs_equal(const adns_sockaddr *a,
413 const adns_sockaddr *b);
414 /* Returns nonzero if the two refer to the same protocol address
415 * (disregarding port, IPv6 scope, etc).
418 extern int adns__sockaddrs_equal(const struct sockaddr *sa,
419 const struct sockaddr *sb);
420 /* Return nonzero if the two socket addresses are equal (in all significant
424 extern int adns__addr_width(int af);
425 /* Return the width of addresses of family af, in bits. */
427 extern void adns__prefix_mask(adns_sockaddr *sa, int len);
428 /* Stores in sa's protocol address field an address mask for address
429 * family af, whose first len bits are set and the remainder are
430 * clear. On entry, sa's af field must be set. This is what you want
431 * for converting a prefix length into a netmask.
434 extern int adns__guess_prefix_length(const adns_sockaddr *addr);
435 /* Given a network base address, guess the appropriate prefix length based on
436 * the appropriate rules for the address family (e.g., for IPv4, this uses
437 * the old address classes).
440 extern int adns__addr_matches(int af, const void *addr,
441 const adns_sockaddr *base,
442 const adns_sockaddr *mask);
443 /* Return nonzero if the protocol address specified by af and addr
444 * lies within the network specified by base and mask.
447 extern void adns__addr_inject(const void *a, adns_sockaddr *sa);
448 /* Injects the protocol address *a into the socket adress sa. Assumes
449 * that sa->sa_family is already set correctly.
452 extern const void *adns__sockaddr_addr(const struct sockaddr *sa);
453 /* Returns the address of the protocol address field in sa.
456 char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf);
457 /* Converts sa to a string, and writes it to buf, which must be at
458 * least ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Returns buf;
462 extern int adns__make_reverse_domain(const struct sockaddr *sa,
464 char **buf_io, size_t bufsz,
466 /* Construct a reverse domain string, given a socket address and a parent
467 * zone. If zone is null, then use the standard reverse-lookup zone for the
468 * address family. If the length of the resulting string is no larger than
469 * bufsz, then the result is stored starting at *buf_io; otherwise a new
470 * buffer is allocated is used, and a pointer to it is stored in both *buf_io
471 * and *buf_free_r (the latter of which should be null on entry). If
472 * something goes wrong, then an errno value is returned: ENOSYS if the
473 * address family of sa isn't recognized, or ENOMEM if the attempt to
474 * allocate an output buffer failed.
477 extern bool adns__revparse_label(struct revparse_state *rps, int labnum,
479 int labstart, int lablen);
480 /* Parse a label in a reverse-domain name, given its index labnum (starting
481 * from zero), a pointer to its contents (which need not be null-terminated),
482 * and its length. The state in *rps is initialized implicitly when labnum
485 * Returns 1 if the parse is proceeding successfully, 0 if the domain
486 * name is definitely invalid and the parse must be abandoned.
489 extern bool adns__revparse_done(struct revparse_state *rps,
490 const char *dgram, int nlabels,
491 adns_rrtype *rrtype_r, adns_sockaddr *addr_r);
492 /* Finishes parsing a reverse-domain name, given the total number of
493 * labels in the name. On success, fills in the af and protocol
494 * address in *addr_r, and the forward query type in *rrtype_r
495 * (because that turns out to be useful). Returns 1 if the parse
501 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
503 /* From general.c: */
505 void adns__vlprintf(adns_state ads, const char *fmt, va_list al);
506 void adns__lprintf(adns_state ads, const char *fmt,
507 ...) PRINTFFORMAT(2,3);
509 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
510 int serv, adns_query qu, const char *fmt, va_list al);
512 void adns__debug(adns_state ads, int serv, adns_query qu,
513 const char *fmt, ...) PRINTFFORMAT(4,5);
514 void adns__warn(adns_state ads, int serv, adns_query qu,
515 const char *fmt, ...) PRINTFFORMAT(4,5);
516 void adns__diag(adns_state ads, int serv, adns_query qu,
517 const char *fmt, ...) PRINTFFORMAT(4,5);
519 int adns__vbuf_ensure(vbuf *vb, int want);
520 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */
521 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
522 /* 1=>success, 0=>realloc failed */
523 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
524 void adns__vbuf_init(vbuf *vb);
525 void adns__vbuf_free(vbuf *vb);
527 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
529 const byte *dgram, int dglen, int cbyte);
530 /* Unpicks a domain in a datagram and returns a string suitable for
531 * printing it as. Never fails - if an error occurs, it will
532 * return some kind of string describing the error.
534 * serv may be -1 and qu may be 0. vb must have been initialised,
535 * and will be left in an arbitrary consistent state.
537 * Returns either vb->buf, or a pointer to a string literal. Do not modify
538 * vb before using the return value.
541 int adns__getrrsz_default(const typeinfo *typei, adns_rrtype type);
542 /* Default function for the `getrrsz' type hook; returns the `fixed_rrsz'
543 * value from the typeinfo entry.
546 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
547 int (*needswap)(void *context, const void *a, const void *b),
549 /* Does an insertion sort of array which must contain nobjs objects
550 * each sz bytes long. tempbuf must point to a buffer at least
551 * sz bytes long. needswap should return !0 if a>b (strictly, ie
552 * wrong order) 0 if a<=b (ie, order is fine).
555 void adns__sigpipe_protect(adns_state);
556 void adns__sigpipe_unprotect(adns_state);
557 /* If SIGPIPE protection is not disabled, will block all signals except
558 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
559 * Each call to _protect must be followed by a call to _unprotect before
560 * any significant amount of code gets to run, since the old signal mask
561 * is stored in the adns structure.
564 /* From transmit.c: */
566 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
567 const char *owner, int ol,
568 const typeinfo *typei, adns_rrtype type,
569 adns_queryflags flags);
570 /* Assembles a query packet in vb. A new id is allocated and returned.
573 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
574 const byte *qd_dgram, int qd_dglen,
576 adns_rrtype type, adns_queryflags flags);
577 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
578 * That domain must be correct and untruncated.
581 void adns__querysend_tcp(adns_query qu, struct timeval now);
582 /* Query must be in state tcpw/tcpw; it will be sent if possible and
583 * no further processing can be done on it for now. The connection
584 * might be broken, but no reconnect will be attempted.
587 struct udpsocket *adns__udpsocket_by_af(adns_state ads, int af);
588 /* Find the UDP socket structure in ads which has the given address family.
589 * Return null if there isn't one.
591 * This is used during initialization, so ads is only partially filled in.
592 * The requirements are that nudp is set, and that udpsocket[i].af are
593 * defined for 0<=i<nudp.
596 void adns__query_send(adns_query qu, struct timeval now);
597 /* Query must be in state tosend/NONE; it will be moved to a new state,
598 * and no further processing can be done on it for now.
599 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
600 * connected), tcpsent/timew, child/childw or done/output.)
601 * __query_send may decide to use either UDP or TCP depending whether
602 * _qf_usevc is set (or has become set) and whether the query is too
608 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
610 const typeinfo *typei, adns_rrtype type,
611 vbuf *qumsg_vb, int id,
612 adns_queryflags flags, struct timeval now,
614 /* Submits a query (for internal use, called during external submits).
616 * The new query is returned in *query_r, or we return adns_s_nomemory.
618 * The query datagram should already have been assembled in qumsg_vb;
619 * the memory for it is _taken over_ by this routine whether it
620 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
622 * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo
623 * field may be modified by type hooks.
625 * When the child query is done, ctx->callback will be called. The
626 * child will already have been taken off both the global list of
627 * queries in ads and the list of children in the parent. The child
628 * will be freed when the callback returns. The parent will have been
629 * taken off the global childw queue.
631 * The callback should either call adns__query_done, if it is
632 * complete, or adns__query_fail, if an error has occurred, in which
633 * case the other children (if any) will be cancelled. If the parent
634 * has more unfinished children (or has just submitted more) then the
635 * callback may choose to wait for them - it must then put the parent
636 * back on the childw queue.
639 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
640 /* Walks down the searchlist for a query with adns_qf_search.
641 * The query should have just had a negative response, or not had
642 * any queries sent yet, and should not be on any queue.
643 * The query_dgram if any will be freed and forgotten and a new
644 * one constructed from the search_* members of the query.
646 * Cannot fail (in case of error, calls adns__query_fail).
649 void *adns__alloc_interim(adns_query qu, size_t sz);
650 void *adns__alloc_preserved(adns_query qu, size_t sz);
651 /* Allocates some memory, and records which query it came from
652 * and how much there was.
654 * If an error occurs in the query, all the memory from _interim is
655 * simply freed. If the query succeeds, one large buffer will be made
656 * which is big enough for all these allocations, and then
657 * adns__alloc_final will get memory from this buffer.
659 * _alloc_interim can fail (and return 0).
660 * The caller must ensure that the query is failed.
662 * The memory from _preserved is is kept and transferred into the
663 * larger buffer - unless we run out of memory, in which case it too
664 * is freed. When you use _preserved you have to add code to the
665 * x_nomem error exit case in adns__makefinal_query to clear out the
666 * pointers you made to those allocations, because that's when they're
667 * thrown away; you should also make a note in the declaration of
668 * those pointer variables, to note that they are _preserved rather
669 * than _interim. If they're in the answer, note it here:
670 * answer->cname and answer->owner are _preserved.
673 void adns__transfer_interim(adns_query from, adns_query to, void *block);
674 /* Transfers an interim allocation from one query to another, so that
675 * the `to' query will have room for the data when we get to makefinal
676 * and so that the free will happen when the `to' query is freed
677 * rather than the `from' query.
679 * It is legal to call adns__transfer_interim with a null pointer; this
682 * _transfer_interim also ensures that the expiry time of the `to' query
683 * is no later than that of the `from' query, so that child queries'
684 * TTLs get inherited by their parents.
687 void adns__free_interim(adns_query qu, void *p);
688 /* Forget about a block allocated by adns__alloc_interim.
691 void *adns__alloc_mine(adns_query qu, size_t sz);
692 /* Like _interim, but does not record the length for later
693 * copying into the answer. This just ensures that the memory
694 * will be freed when we're done with the query.
697 void *adns__alloc_final(adns_query qu, size_t sz);
698 /* Cannot fail, and cannot return 0.
701 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
702 void adns__makefinal_str(adns_query qu, char **strp);
704 void adns__reset_preserved(adns_query qu);
705 /* Resets all of the memory management stuff etc. to take account of
706 * only the _preserved stuff from _alloc_preserved. Used when we find
707 * an error somewhere and want to just report the error (with perhaps
708 * CNAME, owner, etc. info), and also when we're halfway through RRs
709 * in a datagram and discover that we need to retry the query.
712 void adns__cancel(adns_query qu);
713 void adns__query_done(adns_query qu);
714 void adns__query_fail(adns_query qu, adns_status st);
715 void adns__cancel_children(adns_query qu);
717 void adns__returning(adns_state ads, adns_query qu);
718 /* Must be called before returning from adns any time that we have
719 * progressed (including made, finished or destroyed) queries.
721 * Might reenter adns via internal query callbacks, so
722 * external-faciing functions which call adns__returning should
723 * normally be avoided in internal code. */
725 void adns__intdone_process(adns_state ads);
729 void adns__procdgram(adns_state ads, const byte *dgram, int len,
730 int serv, int viatcp, struct timeval now);
731 /* This function is allowed to cause new datagrams to be constructed
732 * and sent, or even new queries to be started. However,
733 * query-sending functions are not allowed to call any general event
734 * loop functions in case they accidentally call this.
736 * Ie, receiving functions may call sending functions.
737 * Sending functions may NOT call receiving functions.
742 const typeinfo *adns__findtype(adns_rrtype type);
751 int dglen, max, cbyte, namelen;
755 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
756 int serv, adns_query qu,
757 const byte *dgram, int dglen, int max,
758 int dmbegin, int *dmend_rlater);
759 /* Finds labels in a domain in a datagram.
761 * Call this routine first.
762 * dmend_rlater may be null. ads (and of course fls) may not be.
763 * serv may be -1, qu may be null - they are for error reporting.
766 adns_status adns__findlabel_next(findlabel_state *fls,
767 int *lablen_r, int *labstart_r);
768 /* Then, call this one repeatedly.
770 * It will return adns_s_ok if all is well, and tell you the length
771 * and start of successive labels. labstart_r may be null, but
772 * lablen_r must not be.
774 * After the last label, it will return with *lablen_r zero.
775 * Do not then call it again; instead, just throw away the findlabel_state.
777 * *dmend_rlater will have been set to point to the next part of
778 * the datagram after the label (or after the uncompressed part,
779 * if compression was used). *namelen_rlater will have been set
780 * to the length of the domain name (total length of labels plus
781 * 1 for each intervening dot).
783 * If the datagram appears to be truncated, *lablen_r will be -1.
784 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
785 * Do not call _next again.
787 * There may also be errors, in which case *dmend_rlater,
788 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
789 * Do not then call findlabel_next again.
796 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
797 vbuf *vb, parsedomain_flags flags,
798 const byte *dgram, int dglen, int *cbyte_io,
800 /* vb must already have been initialised; it will be reset if necessary.
801 * If there is truncation, vb->used will be set to 0; otherwise
802 * (if there is no error) vb will be null-terminated.
803 * If there is an error vb and *cbyte_io may be left indeterminate.
805 * serv may be -1 and qu may be 0 - they are used for error reporting only.
808 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
809 adns_query qu, vbuf *vb,
810 parsedomain_flags flags,
812 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
813 * for continuing an existing domain or some such of some kind. Also, unlike
814 * _parse_domain, the domain data will be appended to vb, rather than replacing
815 * the existing contents.
818 adns_status adns__findrr(adns_query qu, int serv,
819 const byte *dgram, int dglen, int *cbyte_io,
820 int *type_r, int *class_r, unsigned long *ttl_r,
821 int *rdlen_r, int *rdstart_r,
822 int *ownermatchedquery_r);
823 /* Finds the extent and some of the contents of an RR in a datagram
824 * and does some checks. The datagram is *dgram, length dglen, and
825 * the RR starts at *cbyte_io (which is updated afterwards to point
826 * to the end of the RR).
828 * The type, class, TTL and RRdata length and start are returned iff
829 * the corresponding pointer variables are not null. type_r, class_r
830 * and ttl_r may not be null. The TTL will be capped.
832 * If ownermatchedquery_r != 0 then the owner domain of this
833 * RR will be compared with that in the query (or, if the query
834 * has gone to a CNAME lookup, with the canonical name).
835 * In this case, *ownermatchedquery_r will be set to 0 or 1.
836 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
838 * If there is truncation then *type_r will be set to -1 and
839 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
842 * qu must obviously be non-null.
844 * If an error is returned then *type_r will be undefined too.
847 adns_status adns__findrr_anychk(adns_query qu, int serv,
848 const byte *dgram, int dglen, int *cbyte_io,
849 int *type_r, int *class_r,
850 unsigned long *ttl_r,
851 int *rdlen_r, int *rdstart_r,
852 const byte *eo_dgram, int eo_dglen,
853 int eo_cbyte, int *eo_matched_r);
854 /* Like adns__findrr_checked, except that the datagram and
855 * owner to compare with can be specified explicitly.
857 * If the caller thinks they know what the owner of the RR ought to
858 * be they can pass in details in eo_*: this is another (or perhaps
859 * the same datagram), and a pointer to where the putative owner
860 * starts in that datagram. In this case *eo_matched_r will be set
861 * to 1 if the datagram matched or 0 if it did not. Either
862 * both eo_dgram and eo_matched_r must both be non-null, or they
863 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
864 * The eo datagram and contained owner domain MUST be valid and
868 void adns__update_expires(adns_query qu, unsigned long ttl,
870 /* Updates the `expires' field in the query, so that it doesn't exceed
874 bool adns__labels_equal(const byte *a, int al, const byte *b, int bl);
878 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
879 /* what and why may be both 0, or both non-0. */
881 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
883 void adns__autosys(adns_state ads, struct timeval now);
884 /* Make all the system calls we want to if the application wants us to.
885 * Must not be called from within adns internal processing functions,
886 * lest we end up in recursive descent !
890 adns__timeout_set(adns_query qu, struct timeval now, long ms)
891 { qu->timeout_ms= ms; qu->timeout_started= now; }
894 adns__timeout_clear(adns_query qu)
895 { qu->timeout_ms= 0; timerclear(&qu->timeout_started); }
898 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
899 struct timeval *tv_buf);
900 /* Call with care - might reentrantly cause queries to be completed! */
902 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
903 void adns__fdevents(adns_state ads,
904 const struct pollfd *pollfds, int npollfds,
905 int maxfd, const fd_set *readfds,
906 const fd_set *writefds, const fd_set *exceptfds,
907 struct timeval now, int *r_r);
908 int adns__internal_check(adns_state ads,
909 adns_query *query_io,
910 adns_answer **answer,
913 void adns__timeouts(adns_state ads, int act,
914 struct timeval **tv_io, struct timeval *tvbuf,
916 /* If act is !0, then this will also deal with the TCP connection
917 * if previous events broke it or require it to be connected.
922 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
924 /* Useful static inline functions: */
926 static inline int ctype_whitespace(int c) {
927 return c==' ' || c=='\n' || c=='\t';
929 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
930 static inline int ctype_alpha(int c) {
931 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
933 static inline int ctype_toupper(int c) {
934 return ctype_alpha(c) ? (c & ~32) : c;
936 static inline int ctype_822special(int c) {
937 return strchr("()<>@,;:\\\".[]",c) != 0;
939 static inline int ctype_domainunquoted(int c) {
940 return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
943 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
947 #define MEM_ROUND(sz) \
948 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
949 * sizeof(union maxalign) )
951 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ffu)
952 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
953 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
954 #define GET_L(cb,tv) ( (tv)=0, \
955 (tv)|=(GETIL_B((cb))<<24), \
956 (tv)|=(GETIL_B((cb))<<16), \
957 (tv)|=(GETIL_B((cb))<<8), \