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 Ian Jackson
10 * Copyright (C) 1999-2000,2003,2006 Tony Finch
11 * Copyright (C) 1991 Massachusetts Institute of Technology
12 * (See the file INSTALL for full details.)
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 #ifndef ADNS_INTERNAL_H_INCLUDED
30 #define ADNS_INTERNAL_H_INCLUDED
33 typedef unsigned char byte;
45 #define ADNS_FEATURE_MANYAF
49 #ifdef ADNS_REGRESS_TEST
50 # include "hredirect.h"
53 /* Configuration and constants */
56 #define MAXSORTLIST 15
57 #define UDPMAXRETRIES 15
58 #define UDPRETRYMS 2000
59 #define TCPWAITMS 30000
60 #define TCPCONNMS 14000
61 #define TCPIDLEMS 30000
62 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
65 #define DNS_MAXUDP 512
66 #define DNS_MAXLABEL 63
67 #define DNS_MAXDOMAIN 255
68 #define DNS_HDRSIZE 12
69 #define DNS_IDOFFSET 0
70 #define DNS_CLASS_IN 1
72 #define DNS_INADDR_ARPA "in-addr", "arpa"
73 #define DNS_IP6_ARPA "ip6", "arpa"
75 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
77 /* Some preprocessor hackery */
79 #define GLUE(x, y) GLUE_(x, y)
80 #define GLUE_(x, y) x##y
82 /* C99 macro `...' must match at least one argument, so the naive definition
83 * `#define CAR(car, ...) car' won't work. But it's easy to arrange for the
84 * tail to be nonempty if we're just going to discard it anyway. */
85 #define CAR(...) CAR_(__VA_ARGS__, _)
86 #define CAR_(car, ...) car
88 /* Extracting the tail of an argument list is rather more difficult. The
89 * following trick is based on one by Laurent Deniau to count the number of
90 * arguments to a macro, simplified in two ways: (a) it only handles up to
91 * eight arguments, and (b) it only needs to distinguish the one-argument
92 * case from many arguments. */
93 #define CDR(...) CDR_(__VA_ARGS__, m, m, m, m, m, m, m, 1, _)(__VA_ARGS__)
94 #define CDR_(_1, _2, _3, _4, _5, _6, _7, _8, n, ...) CDR_##n
96 #define CDR_m(_, ...) __VA_ARGS__
102 } consistency_checks;
114 adns__qf_addr_answer= 0x01000000,/* addr query received an answer */
115 adns__qf_addr_cname = 0x02000000 /* addr subquery performed on cname */
118 /* Shared data structures */
130 int dglen, nsstart, nscount, arcount;
134 #define NREVDOMAINS 2 /* keep in sync with addrfam! */
135 struct revparse_state {
136 unsigned map; /* which domains are still live */
137 byte ipv[NREVDOMAINS][32]; /* address components so far */
140 union checklabel_state {
141 struct revparse_state ptr;
146 void (*callback)(adns_query parent, adns_query child);
150 adns_rrtype rev_rrtype;
156 } tinfo; /* type-specific state for the query itself: zero-init if you
157 * don't know better. */
160 adns_rr_hostaddr *hostaddr;
161 } pinfo; /* state for use by parent's callback function */
164 typedef struct typeinfo {
170 void (*makefinal)(adns_query qu, void *data);
171 /* Change memory management of *data.
172 * Previously, used alloc_interim, now use alloc_final.
175 adns_status (*convstring)(vbuf *vb, const void *data);
176 /* Converts the RR data to a string representation in vbuf.
177 * vbuf will be appended to (it must have been initialised),
178 * and will not be null-terminated by convstring.
181 adns_status (*parse)(const parseinfo *pai, int cbyte,
182 int max, void *store_r);
183 /* Parse one RR, in dgram of length dglen, starting at cbyte and
184 * extending until at most max.
186 * The RR should be stored at *store_r, of length qu->typei->getrrsz().
188 * If there is an overrun which might indicate truncation, it should set
189 * *rdstart to -1; otherwise it may set it to anything else positive.
191 * nsstart is the offset of the authority section.
194 int (*diff_needswap)(adns_state ads,const void *datap_a,const void *datap_b);
195 /* Returns !0 if RR a should be strictly after RR b in the sort order,
196 * 0 otherwise. Must not fail.
199 adns_status (*checklabel)(adns_state ads, adns_queryflags flags,
200 union checklabel_state *cls, qcontext *ctx,
201 int labnum, const char *label, 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 *label, 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;
375 int nextid, tcpsocket;
376 struct udpsocket { int af; int fd; } udpsocket[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 short rand48xsubi[3];
401 /* From addrfam.c: */
403 extern int adns__addrs_equal_raw(const struct sockaddr *a,
404 int bf, const void *b);
405 /* Returns nonzero a's family is bf and a's protocol address field
406 * refers to the same protocol address as that stored at ba.
409 extern int adns__addrs_equal(const adns_sockaddr *a,
410 const adns_sockaddr *b);
411 /* Returns nonzero if the two refer to the same protocol address
412 * (disregarding port, IPv6 scope, etc).
415 extern int adns__sockaddrs_equal(const struct sockaddr *sa,
416 const struct sockaddr *sb);
417 /* Return nonzero if the two socket addresses are equal (in all significant
421 extern int adns__addr_width(int af);
422 /* Return the width of addresses of family af, in bits. */
424 extern void adns__prefix_mask(adns_sockaddr *sa, int len);
425 /* Stores in sa's protocol address field an address mask for address
426 * family af, whose first len bits are set and the remainder are
427 * clear. On entry, sa's af field must be set. This is what you want
428 * for converting a prefix length into a netmask.
431 extern int adns__guess_prefix_length(const adns_sockaddr *addr);
432 /* Given a network base address, guess the appropriate prefix length based on
433 * the appropriate rules for the address family (e.g., for IPv4, this uses
434 * the old address classes).
437 extern int adns__addr_matches(int af, const void *addr,
438 const adns_sockaddr *base,
439 const adns_sockaddr *mask);
440 /* Return nonzero if the protocol address specified by af and addr
441 * lies within the network specified by base and mask.
444 extern void adns__addr_inject(const void *a, adns_sockaddr *sa);
445 /* Injects the protocol address *a into the socket adress sa. Assumes
446 * that sa->sa_family is already set correctly.
449 extern const void *adns__sockaddr_addr(const struct sockaddr *sa);
450 /* Returns the address of the protocol address field in sa.
453 char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf);
454 /* Convert sa to a string, and write it to buf, which must be at least
455 * ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Return buf; can't fail.
458 extern int adns__make_reverse_domain(const struct sockaddr *sa,
460 char **buf_io, size_t bufsz,
462 /* Construct a reverse domain string, given a socket address and a parent
463 * zone. If zone is null, then use the standard reverse-lookup zone for the
464 * address family. If the length of the resulting string is no larger than
465 * bufsz, then the result is stored starting at *buf_io; otherwise a new
466 * buffer is allocated is used, and a pointer to it is stored in both *buf_io
467 * and *buf_free_r (the latter of which should be null on entry). If
468 * something goes wrong, then an errno value is returned: ENOSYS if the
469 * address family of sa isn't recognized, or ENOMEM if the attempt to
470 * allocate an output buffer failed.
473 extern int adns__revparse_label(struct revparse_state *rps, int labnum,
474 const char *label, int lablen);
475 /* Parse a label in a reverse-domain name, given its index labnum (starting
476 * from zero), a pointer to its contents (which need not be null-terminated),
477 * and its length. The state in *rps is initialized implicitly when labnum
480 * Returns zero if the parse was successful, nonzero if the domain name is
481 * definitely invalid and the parse must be abandoned.
484 extern int adns__revparse_done(struct revparse_state *rps, int nlabels,
485 adns_rrtype *rrtype_r, adns_sockaddr *addr_r);
486 /* Finishes parsing a reverse-domain name, given the total number of
487 * labels in the name. On success, fills in the af and protocol
488 * address in *addr_r, and the forward query type in *rrtype_r
489 * (because that turns out to be useful). Returns nonzero if the
490 * parse must be abandoned.
495 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
497 /* From general.c: */
499 void adns__vlprintf(adns_state ads, const char *fmt, va_list al);
500 void adns__lprintf(adns_state ads, const char *fmt,
501 ...) PRINTFFORMAT(2,3);
503 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
504 int serv, adns_query qu, const char *fmt, va_list al);
506 void adns__debug(adns_state ads, int serv, adns_query qu,
507 const char *fmt, ...) PRINTFFORMAT(4,5);
508 void adns__warn(adns_state ads, int serv, adns_query qu,
509 const char *fmt, ...) PRINTFFORMAT(4,5);
510 void adns__diag(adns_state ads, int serv, adns_query qu,
511 const char *fmt, ...) PRINTFFORMAT(4,5);
513 int adns__vbuf_ensure(vbuf *vb, int want);
514 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */
515 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
516 /* 1=>success, 0=>realloc failed */
517 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
518 void adns__vbuf_init(vbuf *vb);
519 void adns__vbuf_free(vbuf *vb);
521 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
523 const byte *dgram, int dglen, int cbyte);
524 /* Unpicks a domain in a datagram and returns a string suitable for
525 * printing it as. Never fails - if an error occurs, it will
526 * return some kind of string describing the error.
528 * serv may be -1 and qu may be 0. vb must have been initialised,
529 * and will be left in an arbitrary consistent state.
531 * Returns either vb->buf, or a pointer to a string literal. Do not modify
532 * vb before using the return value.
535 int adns__getrrsz_default(const typeinfo *typei, adns_rrtype type);
536 /* Default function for the `getrrsz' type hook; returns the `fixed_rrsz'
537 * value from the typeinfo entry.
540 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
541 int (*needswap)(void *context, const void *a, const void *b),
543 /* Does an insertion sort of array which must contain nobjs objects
544 * each sz bytes long. tempbuf must point to a buffer at least
545 * sz bytes long. needswap should return !0 if a>b (strictly, ie
546 * wrong order) 0 if a<=b (ie, order is fine).
549 void adns__sigpipe_protect(adns_state);
550 void adns__sigpipe_unprotect(adns_state);
551 /* If SIGPIPE protection is not disabled, will block all signals except
552 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
553 * Each call to _protect must be followed by a call to _unprotect before
554 * any significant amount of code gets to run, since the old signal mask
555 * is stored in the adns structure.
558 /* From transmit.c: */
560 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
561 const char *owner, int ol,
562 const typeinfo *typei, adns_rrtype type,
563 adns_queryflags flags);
564 /* Assembles a query packet in vb. A new id is allocated and returned.
567 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
568 const byte *qd_dgram, int qd_dglen,
570 adns_rrtype type, adns_queryflags flags);
571 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
572 * That domain must be correct and untruncated.
575 void adns__querysend_tcp(adns_query qu, struct timeval now);
576 /* Query must be in state tcpw/tcpw; it will be sent if possible and
577 * no further processing can be done on it for now. The connection
578 * might be broken, but no reconnect will be attempted.
581 struct udpsocket *adns__udpsocket_by_af(adns_state ads, int af);
582 /* Find the UDP socket structure in ads which has the given address family.
583 * Return null if there isn't one.
585 * This is used during initialization, so ads is only partially filled in.
586 * The requirements are that nudp is set, and that udpsocket[i].af are
587 * defined for 0<=i<nudp.
590 void adns__query_send(adns_query qu, struct timeval now);
591 /* Query must be in state tosend/NONE; it will be moved to a new state,
592 * and no further processing can be done on it for now.
593 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
594 * connected), tcpsent/timew, child/childw or done/output.)
595 * __query_send may decide to use either UDP or TCP depending whether
596 * _qf_usevc is set (or has become set) and whether the query is too
602 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
604 const typeinfo *typei, adns_rrtype type,
605 vbuf *qumsg_vb, int id,
606 adns_queryflags flags, struct timeval now,
608 /* Submits a query (for internal use, called during external submits).
610 * The new query is returned in *query_r, or we return adns_s_nomemory.
612 * The query datagram should already have been assembled in qumsg_vb;
613 * the memory for it is _taken over_ by this routine whether it
614 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
616 * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo
617 * field may be modified by type hooks.
619 * When the child query is done, ctx->callback will be called. The
620 * child will already have been taken off both the global list of
621 * queries in ads and the list of children in the parent. The child
622 * will be freed when the callback returns. The parent will have been
623 * taken off the global childw queue.
625 * The callback should either call adns__query_done, if it is
626 * complete, or adns__query_fail, if an error has occurred, in which
627 * case the other children (if any) will be cancelled. If the parent
628 * has more unfinished children (or has just submitted more) then the
629 * callback may choose to wait for them - it must then put the parent
630 * back on the childw queue.
633 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
634 /* Walks down the searchlist for a query with adns_qf_search.
635 * The query should have just had a negative response, or not had
636 * any queries sent yet, and should not be on any queue.
637 * The query_dgram if any will be freed and forgotten and a new
638 * one constructed from the search_* members of the query.
640 * Cannot fail (in case of error, calls adns__query_fail).
643 void *adns__alloc_interim(adns_query qu, size_t sz);
644 void *adns__alloc_preserved(adns_query qu, size_t sz);
645 /* Allocates some memory, and records which query it came from
646 * and how much there was.
648 * If an error occurs in the query, all the memory from _interim is
649 * simply freed. If the query succeeds, one large buffer will be made
650 * which is big enough for all these allocations, and then
651 * adns__alloc_final will get memory from this buffer.
653 * _alloc_interim can fail (and return 0).
654 * The caller must ensure that the query is failed.
656 * The memory from _preserved is is kept and transferred into the
657 * larger buffer - unless we run out of memory, in which case it too
658 * is freed. When you use _preserved you have to add code to the
659 * x_nomem error exit case in adns__makefinal_query to clear out the
660 * pointers you made to those allocations, because that's when they're
661 * thrown away; you should also make a note in the declaration of
662 * those pointer variables, to note that they are _preserved rather
663 * than _interim. If they're in the answer, note it here:
664 * answer->cname and answer->owner are _preserved.
667 void adns__transfer_interim(adns_query from, adns_query to, void *block);
668 /* Transfers an interim allocation from one query to another, so that
669 * the `to' query will have room for the data when we get to makefinal
670 * and so that the free will happen when the `to' query is freed
671 * rather than the `from' query.
673 * It is legal to call adns__transfer_interim with a null pointer; this
676 * _transfer_interim also ensures that the expiry time of the `to' query
677 * is no later than that of the `from' query, so that child queries'
678 * TTLs get inherited by their parents.
681 void adns__free_interim(adns_query qu, void *p);
682 /* Forget about a block allocated by adns__alloc_interim.
685 void *adns__alloc_mine(adns_query qu, size_t sz);
686 /* Like _interim, but does not record the length for later
687 * copying into the answer. This just ensures that the memory
688 * will be freed when we're done with the query.
691 void *adns__alloc_final(adns_query qu, size_t sz);
692 /* Cannot fail, and cannot return 0.
695 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
696 void adns__makefinal_str(adns_query qu, char **strp);
698 void adns__reset_preserved(adns_query qu);
699 /* Resets all of the memory management stuff etc. to take account of
700 * only the _preserved stuff from _alloc_preserved. Used when we find
701 * an error somewhere and want to just report the error (with perhaps
702 * CNAME, owner, etc. info), and also when we're halfway through RRs
703 * in a datagram and discover that we need to retry the query.
706 void adns__cancel(adns_query qu);
707 void adns__query_done(adns_query qu);
708 void adns__query_fail(adns_query qu, adns_status stat);
709 void adns__cancel_children(adns_query qu);
711 void adns__returning(adns_state ads, adns_query qu);
712 /* Must be called before returning from adns any time that we have
713 * progressed (including made, finished or destroyed) queries.
715 * Might reenter adns via internal query callbacks, so
716 * external-faciing functions which call adns__returning should
717 * normally be avoided in internal code. */
721 void adns__procdgram(adns_state ads, const byte *dgram, int len,
722 int serv, int viatcp, struct timeval now);
723 /* This function is allowed to cause new datagrams to be constructed
724 * and sent, or even new queries to be started. However,
725 * query-sending functions are not allowed to call any general event
726 * loop functions in case they accidentally call this.
728 * Ie, receiving functions may call sending functions.
729 * Sending functions may NOT call receiving functions.
734 const typeinfo *adns__findtype(adns_rrtype type);
743 int dglen, max, cbyte, namelen;
747 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
748 int serv, adns_query qu,
749 const byte *dgram, int dglen, int max,
750 int dmbegin, int *dmend_rlater);
751 /* Finds labels in a domain in a datagram.
753 * Call this routine first.
754 * dmend_rlater may be null. ads (and of course fls) may not be.
755 * serv may be -1, qu may be null - they are for error reporting.
758 adns_status adns__findlabel_next(findlabel_state *fls,
759 int *lablen_r, int *labstart_r);
760 /* Then, call this one repeatedly.
762 * It will return adns_s_ok if all is well, and tell you the length
763 * and start of successive labels. labstart_r may be null, but
764 * lablen_r must not be.
766 * After the last label, it will return with *lablen_r zero.
767 * Do not then call it again; instead, just throw away the findlabel_state.
769 * *dmend_rlater will have been set to point to the next part of
770 * the datagram after the label (or after the uncompressed part,
771 * if compression was used). *namelen_rlater will have been set
772 * to the length of the domain name (total length of labels plus
773 * 1 for each intervening dot).
775 * If the datagram appears to be truncated, *lablen_r will be -1.
776 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
777 * Do not call _next again.
779 * There may also be errors, in which case *dmend_rlater,
780 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
781 * Do not then call findlabel_next again.
788 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
789 vbuf *vb, parsedomain_flags flags,
790 const byte *dgram, int dglen, int *cbyte_io,
792 /* vb must already have been initialised; it will be reset if necessary.
793 * If there is truncation, vb->used will be set to 0; otherwise
794 * (if there is no error) vb will be null-terminated.
795 * If there is an error vb and *cbyte_io may be left indeterminate.
797 * serv may be -1 and qu may be 0 - they are used for error reporting only.
800 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
801 adns_query qu, vbuf *vb,
802 parsedomain_flags flags,
804 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
805 * for continuing an existing domain or some such of some kind. Also, unlike
806 * _parse_domain, the domain data will be appended to vb, rather than replacing
807 * the existing contents.
810 adns_status adns__findrr(adns_query qu, int serv,
811 const byte *dgram, int dglen, int *cbyte_io,
812 int *type_r, int *class_r, unsigned long *ttl_r,
813 int *rdlen_r, int *rdstart_r,
814 int *ownermatchedquery_r);
815 /* Finds the extent and some of the contents of an RR in a datagram
816 * and does some checks. The datagram is *dgram, length dglen, and
817 * the RR starts at *cbyte_io (which is updated afterwards to point
818 * to the end of the RR).
820 * The type, class, TTL and RRdata length and start are returned iff
821 * the corresponding pointer variables are not null. type_r, class_r
822 * and ttl_r may not be null. The TTL will be capped.
824 * If ownermatchedquery_r != 0 then the owner domain of this
825 * RR will be compared with that in the query (or, if the query
826 * has gone to a CNAME lookup, with the canonical name).
827 * In this case, *ownermatchedquery_r will be set to 0 or 1.
828 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
830 * If there is truncation then *type_r will be set to -1 and
831 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
834 * qu must obviously be non-null.
836 * If an error is returned then *type_r will be undefined too.
839 adns_status adns__findrr_anychk(adns_query qu, int serv,
840 const byte *dgram, int dglen, int *cbyte_io,
841 int *type_r, int *class_r,
842 unsigned long *ttl_r,
843 int *rdlen_r, int *rdstart_r,
844 const byte *eo_dgram, int eo_dglen,
845 int eo_cbyte, int *eo_matched_r);
846 /* Like adns__findrr_checked, except that the datagram and
847 * owner to compare with can be specified explicitly.
849 * If the caller thinks they know what the owner of the RR ought to
850 * be they can pass in details in eo_*: this is another (or perhaps
851 * the same datagram), and a pointer to where the putative owner
852 * starts in that datagram. In this case *eo_matched_r will be set
853 * to 1 if the datagram matched or 0 if it did not. Either
854 * both eo_dgram and eo_matched_r must both be non-null, or they
855 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
856 * The eo datagram and contained owner domain MUST be valid and
860 void adns__update_expires(adns_query qu, unsigned long ttl,
862 /* Updates the `expires' field in the query, so that it doesn't exceed
866 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
870 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
871 /* what and why may be both 0, or both non-0. */
873 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
875 void adns__autosys(adns_state ads, struct timeval now);
876 /* Make all the system calls we want to if the application wants us to.
877 * Must not be called from within adns internal processing functions,
878 * lest we end up in recursive descent !
881 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
882 struct timeval *tv_buf);
883 /* Call with care - might reentrantly cause queries to be completed! */
885 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
886 void adns__fdevents(adns_state ads,
887 const struct pollfd *pollfds, int npollfds,
888 int maxfd, const fd_set *readfds,
889 const fd_set *writefds, const fd_set *exceptfds,
890 struct timeval now, int *r_r);
891 int adns__internal_check(adns_state ads,
892 adns_query *query_io,
893 adns_answer **answer,
896 void adns__timeouts(adns_state ads, int act,
897 struct timeval **tv_io, struct timeval *tvbuf,
899 /* If act is !0, then this will also deal with the TCP connection
900 * if previous events broke it or require it to be connected.
905 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
907 /* Useful static inline functions: */
909 static inline int ctype_whitespace(int c) {
910 return c==' ' || c=='\n' || c=='\t';
912 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
913 static inline int ctype_alpha(int c) {
914 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
916 static inline int ctype_822special(int c) {
917 return strchr("()<>@,;:\\\".[]",c) != 0;
919 static inline int ctype_domainunquoted(int c) {
920 return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
923 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
927 #define MEM_ROUND(sz) \
928 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
929 * sizeof(union maxalign) )
931 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
932 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
933 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
934 #define GET_L(cb,tv) ( (tv)=0, \
935 (tv)|=(GETIL_B((cb))<<24), \
936 (tv)|=(GETIL_B((cb))<<16), \
937 (tv)|=(GETIL_B((cb))<<8), \