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;
48 #ifdef ADNS_REGRESS_TEST
49 # include "hredirect.h"
52 /* Configuration and constants */
55 #define MAXSORTLIST 15
56 #define UDPMAXRETRIES 15
57 #define UDPRETRYMS 2000
58 #define TCPWAITMS 30000
59 #define TCPCONNMS 14000
60 #define TCPIDLEMS 30000
61 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
64 #define DNS_MAXUDP 512
65 #define DNS_MAXLABEL 63
66 #define DNS_MAXDOMAIN 255
67 #define DNS_HDRSIZE 12
68 #define DNS_IDOFFSET 0
69 #define DNS_CLASS_IN 1
71 #define DNS_INADDR_ARPA "in-addr", "arpa"
72 #define DNS_IP6_ARPA "ip6", "arpa"
74 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
76 /* Some preprocessor hackery */
78 #define GLUE(x, y) GLUE_(x, y)
79 #define GLUE_(x, y) x##y
81 /* C99 macro `...' must match at least one argument, so the naive definition
82 * `#define CAR(car, ...) car' won't work. But it's easy to arrange for the
83 * tail to be nonempty if we're just going to discard it anyway. */
84 #define CAR(...) CAR_(__VA_ARGS__, _)
85 #define CAR_(car, ...) car
87 /* Extracting the tail of an argument list is rather more difficult. The
88 * following trick is based on one by Laurent Deniau to count the number of
89 * arguments to a macro, simplified in two ways: (a) it only handles up to
90 * eight arguments, and (b) it only needs to distinguish the one-argument
91 * case from many arguments. */
92 #define CDR(...) CDR_(__VA_ARGS__, m, m, m, m, m, m, m, 1, _)(__VA_ARGS__)
93 #define CDR_(_1, _2, _3, _4, _5, _6, _7, _8, n, ...) CDR_##n
95 #define CDR_m(_, ...) __VA_ARGS__
101 } consistency_checks;
112 /* Shared data structures */
124 int dglen, nsstart, nscount, arcount;
133 struct af_addr { int af; union gen_addr addr; };
135 #define NREVDOMAINS 2 /* keep in sync with addrfam! */
136 struct revparse_state {
137 unsigned map; /* which domains are still live */
138 byte ipv[NREVDOMAINS][32]; /* address components so far */
141 union checklabel_state {
142 struct revparse_state ptr;
147 void (*callback)(adns_query parent, adns_query child);
151 adns_rrtype rev_rrtype;
157 } tinfo; /* type-specific state for the query itself: zero-init if you
158 * don't know better. */
161 adns_rr_hostaddr *hostaddr;
162 } pinfo; /* state for use by parent's callback function */
165 typedef struct typeinfo {
171 void (*makefinal)(adns_query qu, void *data);
172 /* Change memory management of *data.
173 * Previously, used alloc_interim, now use alloc_final.
176 adns_status (*convstring)(vbuf *vb, const void *data);
177 /* Converts the RR data to a string representation in vbuf.
178 * vbuf will be appended to (it must have been initialised),
179 * and will not be null-terminated by convstring.
182 adns_status (*parse)(const parseinfo *pai, int cbyte,
183 int max, void *store_r);
184 /* Parse one RR, in dgram of length dglen, starting at cbyte and
185 * extending until at most max.
187 * The RR should be stored at *store_r, of length qu->typei->getrrsz().
189 * If there is an overrun which might indicate truncation, it should set
190 * *rdstart to -1; otherwise it may set it to anything else positive.
192 * nsstart is the offset of the authority section.
195 int (*diff_needswap)(adns_state ads,const void *datap_a,const void *datap_b);
196 /* Returns !0 if RR a should be strictly after RR b in the sort order,
197 * 0 otherwise. Must not fail.
200 adns_status (*checklabel)(adns_state ads, adns_queryflags flags,
201 union checklabel_state *cls, qcontext *ctx,
202 int labnum, const char *label, int lablen);
203 /* Check a label from the query domain string. The label is not
204 * necessarily null-terminated. The hook can refuse the query's submission
205 * by returning a nonzero status. State can be stored in *cls between
206 * calls, and useful information can be stashed in ctx->tinfo, to be stored
207 * with the query (e.g., it will be available to the parse hook). This
208 * hook can detect a first call because labnum is zero, and a final call
209 * because lablen is zero.
212 void (*postsort)(adns_state ads, void *array, int nrrs,int rrsz,
213 const struct typeinfo *typei);
214 /* Called immediately after the RRs have been sorted, and may rearrange
215 * them. (This is really for the benefit of SRV's bizarre weighting
216 * stuff.) May be 0 to mean nothing needs to be done.
219 int (*getrrsz)(const struct typeinfo *typei, adns_rrtype type);
220 /* Return the output resource-record element size; if this is null, then
221 * the rrsz member can be used.
224 void (*query_send)(adns_query qu, struct timeval now);
225 /* Send the query to nameservers, and hook it into the appropriate queue.
226 * Normal behaviour is to call adns__query_send, but this can be overridden
227 * for special effects.
231 adns_status adns__ckl_hostname(adns_state ads, adns_queryflags flags,
232 union checklabel_state *cls,
233 qcontext *ctx, int labnum,
234 const char *label, int lablen);
235 /* implemented in query.c, used by types.c as default
236 * and as part of implementation for some fancier types
237 * doesn't require any state */
239 typedef struct allocnode {
240 struct allocnode *next, *back;
255 enum { query_tosend, query_tcpw, query_childw, query_done } state;
256 adns_query back, next, parent;
257 struct { adns_query head, tail; } children;
258 struct { adns_query back, next; } siblings;
259 struct { allocnode *head, *tail; } allocations;
260 int interim_allocd, preserved_allocd;
261 void *final_allocspace;
263 const typeinfo *typei;
268 /* General-purpose messing-about buffer.
269 * Wherever a `big' interface is crossed, this may be corrupted/changed
270 * unless otherwise specified.
274 /* This is allocated when a query is submitted, to avoid being unable
275 * to relate errors to queries if we run out of memory. During
276 * query processing status, rrs is 0. cname is set if
277 * we found a cname (this corresponds to cname_dgram in the query
278 * structure). type is set from the word go. nrrs and rrs
279 * are set together, when we find how many rrs there are.
280 * owner is set during querying unless we're doing searchlist,
281 * in which case it is set only when we find an answer.
285 int cname_dglen, cname_begin;
286 /* If non-0, has been allocated using . */
289 int search_origlen, search_pos, search_doneabs;
290 /* Used by the searching algorithm. The query domain in textual form
291 * is copied into the vbuf, and _origlen set to its length. Then
292 * we walk the searchlist, if we want to. _pos says where we are
293 * (next entry to try), and _doneabs says whether we've done the
294 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
295 * but not done yet). If flags doesn't have adns_qf_search then
296 * the vbuf is initialised but empty and everything else is zero.
299 int id, flags, retries;
301 unsigned long udpsent; /* bitmap indexed by server */
302 struct timeval timeout;
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 * +------------------------+
326 * START -----> | tosend/NONE |
327 * +------------------------+
329 * too big for UDP / UDP timeout \ \ send via UDP
330 * send via TCP / more retries \ \
331 * when conn'd / desired \ \
334 * +-----------+ +-------------+
335 * | tcpw/tcpw | ________ | tosend/udpw |
336 * +-----------+ \ +-------------+
337 * | | | UDP timeout | |
340 * \ | TCP died | desired | |
342 * \ \ servers | TCP / |
343 * \ \ to try | timeout / |
345 * reply \ _| +------------------+ / reply
346 * \ | done/output FAIL | /
347 * \ +------------------+ /
350 * (..... got reply ....)
352 * need child query/ies / \ no child query
355 * +---------------+ +----------------+
356 * | childw/childw | ----------------> | done/output OK |
357 * +---------------+ children done +----------------+
361 struct query_queue { adns_query head, tail; };
366 adns_initflags iflags;
367 adns_logcallbackfn *logfn;
370 struct query_queue udpw, tcpw, childw, output;
371 adns_query forallnext;
372 int nextid, tcpsocket;
373 struct udpsocket { int af; int fd; } udpsocket[MAXUDP];
375 vbuf tcpsend, tcprecv;
376 int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
377 enum adns__tcpstate {
378 server_disconnected, server_connecting,
379 server_ok, server_broken
381 struct timeval tcptimeout;
382 /* This will have tv_sec==0 if it is not valid. It will always be
383 * valid if tcpstate _connecting. When _ok, it will be nonzero if
384 * we are idle (ie, tcpw queue is empty), in which case it is the
385 * absolute time when we will close the connection.
387 struct sigaction stdsigpipe;
389 struct pollfd pollfds_buf[MAX_POLLFDS];
390 adns_rr_addr servers[MAXSERVERS];
393 union gen_addr base, mask;
394 } sortlist[MAXSORTLIST];
396 unsigned short rand48xsubi[3];
399 /* From addrfam.c: */
401 extern int adns__af_supported_p(int af);
402 /* Return nonzero if the address family af known to the library and supported
403 * by the other addrfam operations. Note that the other operations will
404 * abort on an unrecognized address family rather than returning an error
408 extern int adns__genaddr_equal_p(int af, const union gen_addr *a,
409 int bf, const void *b);
410 /* b should point to a `struct in_addr' or equivalent for the address family
411 * bf. Returns nonzero if the two addresses are equal.
414 extern int adns__sockaddr_equal_p(const struct sockaddr *sa,
415 const struct sockaddr *sb);
416 /* Return nonzero if the two socket addresses are equal (in all significant
420 extern int adns__addr_width(int af);
421 /* Return the width of addresses of family af, in bits. */
423 extern void adns__prefix_mask(int af, int len, union gen_addr *mask_r);
424 /* Store in mask_r an address mask for address family af, whose first len
425 * bits are set and the remainder are clear. This is what you want for
426 * converting a prefix length into a netmask.
429 extern int adns__guess_prefix_length(int af, const union gen_addr *addr);
430 /* Given a network base address, guess the appropriate prefix length based on
431 * the appropriate rules for the address family (e.g., for IPv4, this uses
432 * the old address classes).
435 extern int adns__addr_match_p(int addraf, const union gen_addr *addr,
436 int netaf, const union gen_addr *base,
437 const union gen_addr *mask);
438 /* Given an address af (with family addraf) and a network (with family netaf,
439 * base address base, and netmask mask), return nonzero if the address lies
440 * within the network.
443 extern void adns__sockaddr_extract(const struct sockaddr *sa,
444 union gen_addr *a_r, int *port_r);
445 /* Extract fields from the socket address, filling in *a_r and *port_r with
446 * the address and (integer, host byte-order) port number, respectively.
447 * Either (or, pointlessly, both) of a_r and port_r may be null to mean
451 extern void adns__sockaddr_inject(const union gen_addr *a, int port,
452 struct sockaddr *sa);
453 /* Inject fields into the socket adress sa. If a is not null, copy the
454 * address in; if port is not -1, then copy the port (converting from host
455 * byte-order). Assumes that sa->sa_family is already set correctly.
458 char *adns__sockaddr_ntoa(const struct sockaddr *sa, char *buf);
459 /* Convert sa to a string, and write it to buf, which must be at least
460 * ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Return buf; can't fail.
463 extern int adns__make_reverse_domain(const struct sockaddr *sa,
465 char **buf_io, size_t bufsz,
467 /* Construct a reverse domain string, given a socket address and a parent
468 * zone. If zone is null, then use the standard reverse-lookup zone for the
469 * address family. If the length of the resulting string is no larger than
470 * bufsz, then the result is stored starting at *buf_io; otherwise a new
471 * buffer is allocated is used, and a pointer to it is stored in both *buf_io
472 * and *buf_free_r (the latter of which should be null on entry). If
473 * something goes wrong, then an errno value is returned: ENOSYS if the
474 * address family of sa isn't recognized, or ENOMEM if the attempt to
475 * allocate an output buffer failed.
478 extern int adns__revparse_label(struct revparse_state *rps, int labnum,
479 const char *label, 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 zero if the parse was successful, nonzero if the domain name is
486 * definitely invalid and the parse must be abandoned.
489 extern int adns__revparse_done(struct revparse_state *rps, int nlabels,
490 adns_rrtype *rrtype_r, struct af_addr *addr_r);
491 /* Finishes parsing a reverse-domain name, given the total number of labels
492 * in the name. On success, fills in the address in *addr_r, and the forward
493 * query type in *rrtype_r (because that turns out to be useful). Returns
494 * nonzero if the parse must be abandoned.
499 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
501 /* From general.c: */
503 void adns__vlprintf(adns_state ads, const char *fmt, va_list al);
504 void adns__lprintf(adns_state ads, const char *fmt,
505 ...) PRINTFFORMAT(2,3);
507 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
508 int serv, adns_query qu, const char *fmt, va_list al);
510 void adns__debug(adns_state ads, int serv, adns_query qu,
511 const char *fmt, ...) PRINTFFORMAT(4,5);
512 void adns__warn(adns_state ads, int serv, adns_query qu,
513 const char *fmt, ...) PRINTFFORMAT(4,5);
514 void adns__diag(adns_state ads, int serv, adns_query qu,
515 const char *fmt, ...) PRINTFFORMAT(4,5);
517 int adns__vbuf_ensure(vbuf *vb, int want);
518 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */
519 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
520 /* 1=>success, 0=>realloc failed */
521 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
522 void adns__vbuf_init(vbuf *vb);
523 void adns__vbuf_free(vbuf *vb);
525 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
527 const byte *dgram, int dglen, int cbyte);
528 /* Unpicks a domain in a datagram and returns a string suitable for
529 * printing it as. Never fails - if an error occurs, it will
530 * return some kind of string describing the error.
532 * serv may be -1 and qu may be 0. vb must have been initialised,
533 * and will be left in an arbitrary consistent state.
535 * Returns either vb->buf, or a pointer to a string literal. Do not modify
536 * vb before using the return value.
539 int adns__getrrsz_default(const typeinfo *typei, adns_rrtype type);
540 /* Default function for the `getrrsz' type hook; returns the `fixed_rrsz'
541 * value from the typeinfo entry.
544 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
545 int (*needswap)(void *context, const void *a, const void *b),
547 /* Does an insertion sort of array which must contain nobjs objects
548 * each sz bytes long. tempbuf must point to a buffer at least
549 * sz bytes long. needswap should return !0 if a>b (strictly, ie
550 * wrong order) 0 if a<=b (ie, order is fine).
553 void adns__sigpipe_protect(adns_state);
554 void adns__sigpipe_unprotect(adns_state);
555 /* If SIGPIPE protection is not disabled, will block all signals except
556 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
557 * Each call to _protect must be followed by a call to _unprotect before
558 * any significant amount of code gets to run, since the old signal mask
559 * is stored in the adns structure.
562 /* From transmit.c: */
564 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
565 const char *owner, int ol,
566 const typeinfo *typei, adns_rrtype type,
567 adns_queryflags flags);
568 /* Assembles a query packet in vb. A new id is allocated and returned.
571 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
572 const byte *qd_dgram, int qd_dglen,
574 adns_rrtype type, adns_queryflags flags);
575 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
576 * That domain must be correct and untruncated.
579 void adns__querysend_tcp(adns_query qu, struct timeval now);
580 /* Query must be in state tcpw/tcpw; it will be sent if possible and
581 * no further processing can be done on it for now. The connection
582 * might be broken, but no reconnect will be attempted.
585 struct udpsocket *adns__udpsocket_by_af(adns_state ads, int af);
586 /* Find the UDP socket structure in ads which has the given address family.
587 * Return null if there isn't one.
589 * This is used during initialization, so ads is only partially filled in.
590 * The requirements are that nudp is set, and that udpsocket[i].af are
591 * defined for 0<=i<nudp.
594 void adns__query_send(adns_query qu, struct timeval now);
595 /* Query must be in state tosend/NONE; it will be moved to a new state,
596 * and no further processing can be done on it for now.
597 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
598 * connected), tcpsent/timew, child/childw or done/output.)
599 * __query_send may decide to use either UDP or TCP depending whether
600 * _qf_usevc is set (or has become set) and whether the query is too
606 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
607 const typeinfo *typei, adns_rrtype type,
608 vbuf *qumsg_vb, int id,
609 adns_queryflags flags, struct timeval now,
611 /* Submits a query (for internal use, called during external submits).
613 * The new query is returned in *query_r, or we return adns_s_nomemory.
615 * The query datagram should already have been assembled in qumsg_vb;
616 * the memory for it is _taken over_ by this routine whether it
617 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
619 * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo
620 * field may be modified by type hooks.
622 * When the child query is done, ctx->callback will be called. The
623 * child will already have been taken off both the global list of
624 * queries in ads and the list of children in the parent. The child
625 * will be freed when the callback returns. The parent will have been
626 * taken off the global childw queue.
628 * The callback should either call adns__query_done, if it is
629 * complete, or adns__query_fail, if an error has occurred, in which
630 * case the other children (if any) will be cancelled. If the parent
631 * has more unfinished children (or has just submitted more) then the
632 * callback may choose to wait for them - it must then put the parent
633 * back on the childw queue.
636 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
637 /* Walks down the searchlist for a query with adns_qf_search.
638 * The query should have just had a negative response, or not had
639 * any queries sent yet, and should not be on any queue.
640 * The query_dgram if any will be freed and forgotten and a new
641 * one constructed from the search_* members of the query.
643 * Cannot fail (in case of error, calls adns__query_fail).
646 void *adns__alloc_interim(adns_query qu, size_t sz);
647 void *adns__alloc_preserved(adns_query qu, size_t sz);
648 /* Allocates some memory, and records which query it came from
649 * and how much there was.
651 * If an error occurs in the query, all the memory from _interim is
652 * simply freed. If the query succeeds, one large buffer will be made
653 * which is big enough for all these allocations, and then
654 * adns__alloc_final will get memory from this buffer.
656 * _alloc_interim can fail (and return 0).
657 * The caller must ensure that the query is failed.
659 * The memory from _preserved is is kept and transferred into the
660 * larger buffer - unless we run out of memory, in which case it too
661 * is freed. When you use _preserved you have to add code to the
662 * x_nomem error exit case in adns__makefinal_query to clear out the
663 * pointers you made to those allocations, because that's when they're
664 * thrown away; you should also make a note in the declaration of
665 * those pointer variables, to note that they are _preserved rather
666 * than _interim. If they're in the answer, note it here:
667 * answer->cname and answer->owner are _preserved.
670 void adns__transfer_interim(adns_query from, adns_query to, void *block);
671 /* Transfers an interim allocation from one query to another, so that
672 * the `to' query will have room for the data when we get to makefinal
673 * and so that the free will happen when the `to' query is freed
674 * rather than the `from' query.
676 * It is legal to call adns__transfer_interim with a null pointer; this
679 * _transfer_interim also ensures that the expiry time of the `to' query
680 * is no later than that of the `from' query, so that child queries'
681 * TTLs get inherited by their parents.
684 void adns__free_interim(adns_query qu, void *p);
685 /* Forget about a block allocated by adns__alloc_interim.
688 void *adns__alloc_mine(adns_query qu, size_t sz);
689 /* Like _interim, but does not record the length for later
690 * copying into the answer. This just ensures that the memory
691 * will be freed when we're done with the query.
694 void *adns__alloc_final(adns_query qu, size_t sz);
695 /* Cannot fail, and cannot return 0.
698 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
699 void adns__makefinal_str(adns_query qu, char **strp);
701 void adns__reset_preserved(adns_query qu);
702 /* Resets all of the memory management stuff etc. to take account of
703 * only the _preserved stuff from _alloc_preserved. Used when we find
704 * an error somewhere and want to just report the error (with perhaps
705 * CNAME, owner, etc. info), and also when we're halfway through RRs
706 * in a datagram and discover that we need to retry the query.
709 void adns__query_done(adns_query qu);
710 void adns__query_fail(adns_query qu, adns_status stat);
711 void adns__cancel_children(adns_query qu);
715 void adns__procdgram(adns_state ads, const byte *dgram, int len,
716 int serv, int viatcp, struct timeval now);
717 /* This function is allowed to cause new datagrams to be constructed
718 * and sent, or even new queries to be started. However,
719 * query-sending functions are not allowed to call any general event
720 * loop functions in case they accidentally call this.
722 * Ie, receiving functions may call sending functions.
723 * Sending functions may NOT call receiving functions.
728 const typeinfo *adns__findtype(adns_rrtype type);
737 int dglen, max, cbyte, namelen;
741 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
742 int serv, adns_query qu,
743 const byte *dgram, int dglen, int max,
744 int dmbegin, int *dmend_rlater);
745 /* Finds labels in a domain in a datagram.
747 * Call this routine first.
748 * dmend_rlater may be null. ads (and of course fls) may not be.
749 * serv may be -1, qu may be null - they are for error reporting.
752 adns_status adns__findlabel_next(findlabel_state *fls,
753 int *lablen_r, int *labstart_r);
754 /* Then, call this one repeatedly.
756 * It will return adns_s_ok if all is well, and tell you the length
757 * and start of successive labels. labstart_r may be null, but
758 * lablen_r must not be.
760 * After the last label, it will return with *lablen_r zero.
761 * Do not then call it again; instead, just throw away the findlabel_state.
763 * *dmend_rlater will have been set to point to the next part of
764 * the datagram after the label (or after the uncompressed part,
765 * if compression was used). *namelen_rlater will have been set
766 * to the length of the domain name (total length of labels plus
767 * 1 for each intervening dot).
769 * If the datagram appears to be truncated, *lablen_r will be -1.
770 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
771 * Do not call _next again.
773 * There may also be errors, in which case *dmend_rlater,
774 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
775 * Do not then call findlabel_next again.
782 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
783 vbuf *vb, parsedomain_flags flags,
784 const byte *dgram, int dglen, int *cbyte_io,
786 /* vb must already have been initialised; it will be reset if necessary.
787 * If there is truncation, vb->used will be set to 0; otherwise
788 * (if there is no error) vb will be null-terminated.
789 * If there is an error vb and *cbyte_io may be left indeterminate.
791 * serv may be -1 and qu may be 0 - they are used for error reporting only.
794 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
795 adns_query qu, vbuf *vb,
796 parsedomain_flags flags,
798 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
799 * for continuing an existing domain or some such of some kind. Also, unlike
800 * _parse_domain, the domain data will be appended to vb, rather than replacing
801 * the existing contents.
804 adns_status adns__findrr(adns_query qu, int serv,
805 const byte *dgram, int dglen, int *cbyte_io,
806 int *type_r, int *class_r, unsigned long *ttl_r,
807 int *rdlen_r, int *rdstart_r,
808 int *ownermatchedquery_r);
809 /* Finds the extent and some of the contents of an RR in a datagram
810 * and does some checks. The datagram is *dgram, length dglen, and
811 * the RR starts at *cbyte_io (which is updated afterwards to point
812 * to the end of the RR).
814 * The type, class, TTL and RRdata length and start are returned iff
815 * the corresponding pointer variables are not null. type_r, class_r
816 * and ttl_r may not be null. The TTL will be capped.
818 * If ownermatchedquery_r != 0 then the owner domain of this
819 * RR will be compared with that in the query (or, if the query
820 * has gone to a CNAME lookup, with the canonical name).
821 * In this case, *ownermatchedquery_r will be set to 0 or 1.
822 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
824 * If there is truncation then *type_r will be set to -1 and
825 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
828 * qu must obviously be non-null.
830 * If an error is returned then *type_r will be undefined too.
833 adns_status adns__findrr_anychk(adns_query qu, int serv,
834 const byte *dgram, int dglen, int *cbyte_io,
835 int *type_r, int *class_r,
836 unsigned long *ttl_r,
837 int *rdlen_r, int *rdstart_r,
838 const byte *eo_dgram, int eo_dglen,
839 int eo_cbyte, int *eo_matched_r);
840 /* Like adns__findrr_checked, except that the datagram and
841 * owner to compare with can be specified explicitly.
843 * If the caller thinks they know what the owner of the RR ought to
844 * be they can pass in details in eo_*: this is another (or perhaps
845 * the same datagram), and a pointer to where the putative owner
846 * starts in that datagram. In this case *eo_matched_r will be set
847 * to 1 if the datagram matched or 0 if it did not. Either
848 * both eo_dgram and eo_matched_r must both be non-null, or they
849 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
850 * The eo datagram and contained owner domain MUST be valid and
854 void adns__update_expires(adns_query qu, unsigned long ttl,
856 /* Updates the `expires' field in the query, so that it doesn't exceed
860 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
864 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
865 /* what and why may be both 0, or both non-0. */
867 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
869 void adns__autosys(adns_state ads, struct timeval now);
870 /* Make all the system calls we want to if the application wants us to.
871 * Must not be called from within adns internal processing functions,
872 * lest we end up in recursive descent !
875 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
876 struct timeval *tv_buf);
878 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
879 void adns__fdevents(adns_state ads,
880 const struct pollfd *pollfds, int npollfds,
881 int maxfd, const fd_set *readfds,
882 const fd_set *writefds, const fd_set *exceptfds,
883 struct timeval now, int *r_r);
884 int adns__internal_check(adns_state ads,
885 adns_query *query_io,
886 adns_answer **answer,
889 void adns__timeouts(adns_state ads, int act,
890 struct timeval **tv_io, struct timeval *tvbuf,
892 /* If act is !0, then this will also deal with the TCP connection
893 * if previous events broke it or require it to be connected.
898 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
900 /* Useful static inline functions: */
902 static inline int ctype_whitespace(int c) {
903 return c==' ' || c=='\n' || c=='\t';
905 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
906 static inline int ctype_alpha(int c) {
907 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
909 static inline int ctype_822special(int c) {
910 return strchr("()<>@,;:\\\".[]",c) != 0;
912 static inline int ctype_domainunquoted(int c) {
913 return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
916 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
920 #define MEM_ROUND(sz) \
921 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
922 * sizeof(union maxalign) )
924 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
925 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
926 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
927 #define GET_L(cb,tv) ( (tv)=0, \
928 (tv)|=(GETIL_B((cb))<<24), \
929 (tv)|=(GETIL_B((cb))<<16), \
930 (tv)|=(GETIL_B((cb))<<8), \