3 * - declarations of private objects with external linkage (adns__*)
4 * - definitons of internal macros
5 * - comments regarding library data structures
9 * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
11 * It is part of adns, which is
12 * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
13 * Copyright (C) 1999 Tony Finch <dot@dotat.at>
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 2, 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,
27 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
30 #ifndef ADNS_INTERNAL_H_INCLUDED
31 #define ADNS_INTERNAL_H_INCLUDED
34 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"
73 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
90 /* Shared data structures */
111 int dglen, nsstart, nscount, arcount;
121 void (*makefinal)(adns_query qu, void *data);
122 /* Change memory management of *data.
123 * Previously, used alloc_interim, now use alloc_final.
126 adns_status (*convstring)(vbuf *vb, const void *data);
127 /* Converts the RR data to a string representation in vbuf.
128 * vbuf will be appended to (it must have been initialised),
129 * and will not be null-terminated by convstring.
132 adns_status (*parse)(const parseinfo *pai, int cbyte, int max, void *store_r);
133 /* Parse one RR, in dgram of length dglen, starting at cbyte and
134 * extending until at most max.
136 * The RR should be stored at *store_r, of length qu->typei->rrsz.
138 * If there is an overrun which might indicate truncation, it should set
139 * *rdstart to -1; otherwise it may set it to anything else positive.
141 * nsstart is the offset of the authority section.
144 int (*diff_needswap)(adns_state ads, const void *datap_a, const void *datap_b);
145 /* Returns !0 if RR a should be strictly after RR b in the sort order,
146 * 0 otherwise. Must not fail.
150 typedef struct allocnode {
151 struct allocnode *next, *back;
165 void (*callback)(adns_query parent, adns_query child);
167 adns_rr_addr ptr_parent_addr;
168 adns_rr_hostaddr *hostaddr;
174 enum { query_tosend, query_tcpw, query_childw, query_done } state;
175 adns_query back, next, parent;
176 struct { adns_query head, tail; } children;
177 struct { adns_query back, next; } siblings;
178 struct { allocnode *head, *tail; } allocations;
179 int interim_allocd, preserved_allocd;
180 void *final_allocspace;
182 const typeinfo *typei;
187 /* General-purpose messing-about buffer.
188 * Wherever a `big' interface is crossed, this may be corrupted/changed
189 * unless otherwise specified.
193 /* This is allocated when a query is submitted, to avoid being unable
194 * to relate errors to queries if we run out of memory. During
195 * query processing status, rrs is 0. cname is set if
196 * we found a cname (this corresponds to cname_dgram in the query
197 * structure). type is set from the word go. nrrs and rrs
198 * are set together, when we find how many rrs there are.
199 * owner is set during querying unless we're doing searchlist,
200 * in which case it is set only when we find an answer.
204 int cname_dglen, cname_begin;
205 /* If non-0, has been allocated using . */
208 int search_origlen, search_pos, search_doneabs;
209 /* Used by the searching algorithm. The query domain in textual form
210 * is copied into the vbuf, and _origlen set to its length. Then
211 * we walk the searchlist, if we want to. _pos says where we are
212 * (next entry to try), and _doneabs says whether we've done the
213 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
214 * but not done yet). If flags doesn't have adns_qf_search then
215 * the vbuf is initialised but empty and everything else is zero.
218 int id, flags, retries;
220 unsigned long udpsent; /* bitmap indexed by server */
221 struct timeval timeout;
222 time_t expires; /* Earliest expiry time of any record we used. */
228 * state Queue child id nextudpserver udpsent tcpfailed
230 * tosend NONE null >=0 0 zero zero
231 * tosend udpw null >=0 any nonzero zero
232 * tosend NONE null >=0 any nonzero zero
234 * tcpw tcpw null >=0 irrelevant any any
236 * child childw set >=0 irrelevant irrelevant irrelevant
237 * child NONE null >=0 irrelevant irrelevant irrelevant
238 * done output null -1 irrelevant irrelevant irrelevant
240 * Queries are only not on a queue when they are actually being processed.
241 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
242 * iff the tcp connection is in state server_ok.
244 * +------------------------+
245 * START -----> | tosend/NONE |
246 * +------------------------+
248 * too big for UDP / UDP timeout \ \ send via UDP
249 * send via TCP / more retries \ \
250 * when conn'd / desired \ \
253 * +-----------+ +-------------+
254 * | tcpw/tcpw | ________ | tosend/udpw |
255 * +-----------+ \ +-------------+
256 * | | | UDP timeout | |
259 * \ | TCP died | desired | |
261 * \ \ servers | TCP / |
262 * \ \ to try | timeout / |
264 * reply \ _| +------------------+ / reply
265 * \ | done/output FAIL | /
266 * \ +------------------+ /
269 * (..... got reply ....)
271 * need child query/ies / \ no child query
274 * +---------------+ +----------------+
275 * | childw/childw | ----------------> | done/output OK |
276 * +---------------+ children done +----------------+
280 struct query_queue { adns_query head, tail; };
283 adns_initflags iflags;
286 struct query_queue udpw, tcpw, childw, output;
287 adns_query forallnext;
288 int nextid, udpsocket, tcpsocket;
289 vbuf tcpsend, tcprecv;
290 int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
291 enum adns__tcpstate {
292 server_disconnected, server_connecting,
293 server_ok, server_broken
295 struct timeval tcptimeout;
296 /* This will have tv_sec==0 if it is not valid. It will always be
297 * valid if tcpstate _connecting. When _ok, it will be nonzero if
298 * we are idle (ie, tcpw queue is empty), in which case it is the
299 * absolute time when we will close the connection.
301 struct sigaction stdsigpipe;
303 struct pollfd pollfds_buf[MAX_POLLFDS];
306 } servers[MAXSERVERS];
308 struct in_addr base, mask;
309 } sortlist[MAXSORTLIST];
315 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
317 /* From general.c: */
319 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
320 int serv, adns_query qu, const char *fmt, va_list al);
322 void adns__debug(adns_state ads, int serv, adns_query qu,
323 const char *fmt, ...) PRINTFFORMAT(4,5);
324 void adns__warn(adns_state ads, int serv, adns_query qu,
325 const char *fmt, ...) PRINTFFORMAT(4,5);
326 void adns__diag(adns_state ads, int serv, adns_query qu,
327 const char *fmt, ...) PRINTFFORMAT(4,5);
329 int adns__vbuf_ensure(vbuf *vb, int want);
330 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
331 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
332 /* 1=>success, 0=>realloc failed */
333 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
334 void adns__vbuf_init(vbuf *vb);
335 void adns__vbuf_free(vbuf *vb);
337 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
338 vbuf *vb, const byte *dgram, int dglen, int cbyte);
339 /* Unpicks a domain in a datagram and returns a string suitable for
340 * printing it as. Never fails - if an error occurs, it will
341 * return some kind of string describing the error.
343 * serv may be -1 and qu may be 0. vb must have been initialised,
344 * and will be left in an arbitrary consistent state.
346 * Returns either vb->buf, or a pointer to a string literal. Do not modify
347 * vb before using the return value.
350 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
351 int (*needswap)(void *context, const void *a, const void *b),
353 /* Does an insertion sort of array which must contain nobjs objects
354 * each sz bytes long. tempbuf must point to a buffer at least
355 * sz bytes long. needswap should return !0 if a>b (strictly, ie
356 * wrong order) 0 if a<=b (ie, order is fine).
359 void adns__sigpipe_protect(adns_state);
360 void adns__sigpipe_unprotect(adns_state);
361 /* If SIGPIPE protection is not disabled, will block all signals except
362 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
363 * Each call to _protect must be followed by a call to _unprotect before
364 * any significant amount of code gets to run, since the old signal mask
365 * is stored in the adns structure.
368 /* From transmit.c: */
370 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
371 const char *owner, int ol,
372 const typeinfo *typei, adns_queryflags flags);
373 /* Assembles a query packet in vb. A new id is allocated and returned.
376 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
377 const byte *qd_dgram, int qd_dglen, int qd_begin,
378 adns_rrtype type, adns_queryflags flags);
379 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
380 * That domain must be correct and untruncated.
383 void adns__querysend_tcp(adns_query qu, struct timeval now);
384 /* Query must be in state tcpw/tcpw; it will be sent if possible and
385 * no further processing can be done on it for now. The connection
386 * might be broken, but no reconnect will be attempted.
389 void adns__query_send(adns_query qu, struct timeval now);
390 /* Query must be in state tosend/NONE; it will be moved to a new state,
391 * and no further processing can be done on it for now.
392 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
393 * tcpsent/timew, child/childw or done/output.)
394 * __query_send may decide to use either UDP or TCP depending whether
395 * _qf_usevc is set (or has become set) and whether the query is too
401 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
402 const typeinfo *typei, vbuf *qumsg_vb, int id,
403 adns_queryflags flags, struct timeval now,
404 const qcontext *ctx);
405 /* Submits a query (for internal use, called during external submits).
407 * The new query is returned in *query_r, or we return adns_s_nomemory.
409 * The query datagram should already have been assembled in qumsg_vb;
410 * the memory for it is _taken over_ by this routine whether it
411 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
413 * *ctx is copied byte-for-byte into the query.
415 * When the child query is done, ctx->callback will be called. The
416 * child will already have been taken off both the global list of
417 * queries in ads and the list of children in the parent. The child
418 * will be freed when the callback returns. The parent will have been
419 * taken off the global childw queue.
421 * The callback should either call adns__query_done, if it is
422 * complete, or adns__query_fail, if an error has occurred, in which
423 * case the other children (if any) will be cancelled. If the parent
424 * has more unfinished children (or has just submitted more) then the
425 * callback may choose to wait for them - it must then put the parent
426 * back on the childw queue.
429 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
430 /* Walks down the searchlist for a query with adns_qf_search.
431 * The query should have just had a negative response, or not had
432 * any queries sent yet, and should not be on any queue.
433 * The query_dgram if any will be freed and forgotten and a new
434 * one constructed from the search_* members of the query.
436 * Cannot fail (in case of error, calls adns__query_fail).
439 void *adns__alloc_interim(adns_query qu, size_t sz);
440 void *adns__alloc_preserved(adns_query qu, size_t sz);
441 /* Allocates some memory, and records which query it came from
442 * and how much there was.
444 * If an error occurs in the query, all the memory from _interim is
445 * simply freed. If the query succeeds, one large buffer will be made
446 * which is big enough for all these allocations, and then
447 * adns__alloc_final will get memory from this buffer.
449 * _alloc_interim can fail (and return 0).
450 * The caller must ensure that the query is failed.
452 * The memory from _preserved is is kept and transferred into the
453 * larger buffer - unless we run out of memory, in which case it too
454 * is freed. When you use _preserved you have to add code to the
455 * x_nomem error exit case in adns__makefinal_query to clear out the
456 * pointers you made to those allocations, because that's when they're
457 * thrown away; you should also make a note in the declaration of
458 * those pointer variables, to note that they are _preserved rather
459 * than _interim. If they're in the answer, note it here:
460 * answer->cname and answer->owner are _preserved.
463 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
464 /* Transfers an interim allocation from one query to another, so that
465 * the `to' query will have room for the data when we get to makefinal
466 * and so that the free will happen when the `to' query is freed
467 * rather than the `from' query.
469 * It is legal to call adns__transfer_interim with a null pointer; this
472 * _transfer_interim also ensures that the expiry time of the `to' query
473 * is no later than that of the `from' query, so that child queries'
474 * TTLs get inherited by their parents.
477 void *adns__alloc_mine(adns_query qu, size_t sz);
478 /* Like _interim, but does not record the length for later
479 * copying into the answer. This just ensures that the memory
480 * will be freed when we're done with the query.
483 void *adns__alloc_final(adns_query qu, size_t sz);
484 /* Cannot fail, and cannot return 0.
487 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
488 void adns__makefinal_str(adns_query qu, char **strp);
490 void adns__reset_preserved(adns_query qu);
491 /* Resets all of the memory management stuff etc. to take account of
492 * only the _preserved stuff from _alloc_preserved. Used when we find
493 * an error somewhere and want to just report the error (with perhaps
494 * CNAME, owner, etc. info), and also when we're halfway through RRs
495 * in a datagram and discover that we need to retry the query.
498 void adns__query_done(adns_query qu);
499 void adns__query_fail(adns_query qu, adns_status stat);
503 void adns__procdgram(adns_state ads, const byte *dgram, int len,
504 int serv, int viatcp, struct timeval now);
505 /* This function is allowed to cause new datagrams to be constructed
506 * and sent, or even new queries to be started. However,
507 * query-sending functions are not allowed to call any general event
508 * loop functions in case they accidentally call this.
510 * Ie, receiving functions may call sending functions.
511 * Sending functions may NOT call receiving functions.
516 const typeinfo *adns__findtype(adns_rrtype type);
525 int dglen, max, cbyte, namelen;
529 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
530 int serv, adns_query qu,
531 const byte *dgram, int dglen, int max,
532 int dmbegin, int *dmend_rlater);
533 /* Finds labels in a domain in a datagram.
535 * Call this routine first.
536 * dmend_rlater may be null. ads (and of course fls) may not be.
537 * serv may be -1, qu may be null - they are for error reporting.
540 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
541 /* Then, call this one repeatedly.
543 * It will return adns_s_ok if all is well, and tell you the length
544 * and start of successive labels. labstart_r may be null, but
545 * lablen_r must not be.
547 * After the last label, it will return with *lablen_r zero.
548 * Do not then call it again; instead, just throw away the findlabel_state.
550 * *dmend_rlater will have been set to point to the next part of
551 * the datagram after the label (or after the uncompressed part,
552 * if compression was used). *namelen_rlater will have been set
553 * to the length of the domain name (total length of labels plus
554 * 1 for each intervening dot).
556 * If the datagram appears to be truncated, *lablen_r will be -1.
557 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
558 * Do not call _next again.
560 * There may also be errors, in which case *dmend_rlater,
561 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
562 * Do not then call findlabel_next again.
569 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
570 vbuf *vb, parsedomain_flags flags,
571 const byte *dgram, int dglen, int *cbyte_io, int max);
572 /* vb must already have been initialised; it will be reset if necessary.
573 * If there is truncation, vb->used will be set to 0; otherwise
574 * (if there is no error) vb will be null-terminated.
575 * If there is an error vb and *cbyte_io may be left indeterminate.
577 * serv may be -1 and qu may be 0 - they are used for error reporting only.
580 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
581 adns_query qu, vbuf *vb, parsedomain_flags flags,
583 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
584 * for continuing an existing domain or some such of some kind. Also, unlike
585 * _parse_domain, the domain data will be appended to vb, rather than replacing
586 * the existing contents.
589 adns_status adns__findrr(adns_query qu, int serv,
590 const byte *dgram, int dglen, int *cbyte_io,
591 int *type_r, int *class_r, unsigned long *ttl_r,
592 int *rdlen_r, int *rdstart_r,
593 int *ownermatchedquery_r);
594 /* Finds the extent and some of the contents of an RR in a datagram
595 * and does some checks. The datagram is *dgram, length dglen, and
596 * the RR starts at *cbyte_io (which is updated afterwards to point
597 * to the end of the RR).
599 * The type, class, TTL and RRdata length and start are returned iff
600 * the corresponding pointer variables are not null. type_r, class_r
601 * and ttl_r may not be null. The TTL will be capped.
603 * If ownermatchedquery_r != 0 then the owner domain of this
604 * RR will be compared with that in the query (or, if the query
605 * has gone to a CNAME lookup, with the canonical name).
606 * In this case, *ownermatchedquery_r will be set to 0 or 1.
607 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
609 * If there is truncation then *type_r will be set to -1 and
610 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
613 * qu must obviously be non-null.
615 * If an error is returned then *type_r will be undefined too.
618 adns_status adns__findrr_anychk(adns_query qu, int serv,
619 const byte *dgram, int dglen, int *cbyte_io,
620 int *type_r, int *class_r, unsigned long *ttl_r,
621 int *rdlen_r, int *rdstart_r,
622 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
624 /* Like adns__findrr_checked, except that the datagram and
625 * owner to compare with can be specified explicitly.
627 * If the caller thinks they know what the owner of the RR ought to
628 * be they can pass in details in eo_*: this is another (or perhaps
629 * the same datagram), and a pointer to where the putative owner
630 * starts in that datagram. In this case *eo_matched_r will be set
631 * to 1 if the datagram matched or 0 if it did not. Either
632 * both eo_dgram and eo_matched_r must both be non-null, or they
633 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
634 * The eo datagram and contained owner domain MUST be valid and
638 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now);
639 /* Updates the `expires' field in the query, so that it doesn't exceed
643 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
647 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
648 /* what and why may be both 0, or both non-0. */
650 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
652 void adns__autosys(adns_state ads, struct timeval now);
653 /* Make all the system calls we want to if the application wants us to.
654 * Must not be called from within adns internal processing functions,
655 * lest we end up in recursive descent !
658 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
659 struct timeval *tv_buf);
661 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
662 void adns__fdevents(adns_state ads,
663 const struct pollfd *pollfds, int npollfds,
664 int maxfd, const fd_set *readfds,
665 const fd_set *writefds, const fd_set *exceptfds,
666 struct timeval now, int *r_r);
667 int adns__internal_check(adns_state ads,
668 adns_query *query_io,
669 adns_answer **answer,
672 void adns__timeouts(adns_state ads, int act,
673 struct timeval **tv_io, struct timeval *tvbuf,
675 /* If act is !0, then this will also deal with the TCP connection
676 * if previous events broke it or require it to be connected.
681 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
683 /* Useful static inline functions: */
685 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
686 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
687 static inline int ctype_alpha(int c) {
688 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
690 static inline int ctype_822special(int c) { return strchr("()<>@,;:\\\".[]",c) != 0; }
691 static inline int ctype_domainunquoted(int c) {
692 return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
695 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
699 #define MEM_ROUND(sz) \
700 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
701 * sizeof(union maxalign) )
703 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
704 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
705 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
706 #define GET_L(cb,tv) ( (tv)=0, \
707 (tv)|=(GETIL_B((cb))<<24), \
708 (tv)|=(GETIL_B((cb))<<16), \
709 (tv)|=(GETIL_B((cb))<<8), \