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) 1999-2000 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;
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"
74 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
91 /* Shared data structures */
112 int dglen, nsstart, nscount, arcount;
116 typedef struct typeinfo {
122 void (*makefinal)(adns_query qu, void *data);
123 /* Change memory management of *data.
124 * Previously, used alloc_interim, now use alloc_final.
127 adns_status (*convstring)(vbuf *vb, const void *data);
128 /* Converts the RR data to a string representation in vbuf.
129 * vbuf will be appended to (it must have been initialised),
130 * and will not be null-terminated by convstring.
133 adns_status (*parse)(const parseinfo *pai, int cbyte,
134 int max, void *store_r);
135 /* Parse one RR, in dgram of length dglen, starting at cbyte and
136 * extending until at most max.
138 * The RR should be stored at *store_r, of length qu->typei->rrsz.
140 * If there is an overrun which might indicate truncation, it should set
141 * *rdstart to -1; otherwise it may set it to anything else positive.
143 * nsstart is the offset of the authority section.
146 int (*diff_needswap)(adns_state ads,const void *datap_a,const void *datap_b);
147 /* Returns !0 if RR a should be strictly after RR b in the sort order,
148 * 0 otherwise. Must not fail.
151 adns_status (*qdparselabel)(adns_state ads,
152 const char **p_io, const char *pe, int labelnum,
153 char label_r[DNS_MAXDOMAIN], int *ll_io,
154 adns_queryflags flags,
155 const struct typeinfo *typei);
156 /* Parses one label from the query domain string. On entry, *p_io
157 * points to the next character to parse and *ll_io is the size of
158 * the buffer. pe points just after the end of the query domain
159 * string. On successful return, label_r[] and *ll_io are filled in
160 * and *p_io points to *pe or just after the label-ending `.'. */
164 adns_status adns__qdpl_normal(adns_state ads,
165 const char **p_io, const char *pe, int labelnum,
166 char label_r[], int *ll_io,
167 adns_queryflags flags,
168 const typeinfo *typei);
169 /* implemented in transmit.c, used by types.c as default
170 * and as part of implementation for some fancier types */
172 typedef struct allocnode {
173 struct allocnode *next, *back;
187 void (*callback)(adns_query parent, adns_query child);
189 adns_rr_addr ptr_parent_addr;
190 adns_rr_hostaddr *hostaddr;
196 enum { query_tosend, query_tcpw, query_childw, query_done } state;
197 adns_query back, next, parent;
198 struct { adns_query head, tail; } children;
199 struct { adns_query back, next; } siblings;
200 struct { allocnode *head, *tail; } allocations;
201 int interim_allocd, preserved_allocd;
202 void *final_allocspace;
204 const typeinfo *typei;
209 /* General-purpose messing-about buffer.
210 * Wherever a `big' interface is crossed, this may be corrupted/changed
211 * unless otherwise specified.
215 /* This is allocated when a query is submitted, to avoid being unable
216 * to relate errors to queries if we run out of memory. During
217 * query processing status, rrs is 0. cname is set if
218 * we found a cname (this corresponds to cname_dgram in the query
219 * structure). type is set from the word go. nrrs and rrs
220 * are set together, when we find how many rrs there are.
221 * owner is set during querying unless we're doing searchlist,
222 * in which case it is set only when we find an answer.
226 int cname_dglen, cname_begin;
227 /* If non-0, has been allocated using . */
230 int search_origlen, search_pos, search_doneabs;
231 /* Used by the searching algorithm. The query domain in textual form
232 * is copied into the vbuf, and _origlen set to its length. Then
233 * we walk the searchlist, if we want to. _pos says where we are
234 * (next entry to try), and _doneabs says whether we've done the
235 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
236 * but not done yet). If flags doesn't have adns_qf_search then
237 * the vbuf is initialised but empty and everything else is zero.
240 int id, flags, retries;
242 unsigned long udpsent; /* bitmap indexed by server */
243 struct timeval timeout;
244 time_t expires; /* Earliest expiry time of any record we used. */
250 * state Queue child id nextudpserver udpsent tcpfailed
252 * tosend NONE null >=0 0 zero zero
253 * tosend udpw null >=0 any nonzero zero
254 * tosend NONE null >=0 any nonzero zero
256 * tcpw tcpw null >=0 irrelevant any any
258 * child childw set >=0 irrelevant irrelevant irrelevant
259 * child NONE null >=0 irrelevant irrelevant irrelevant
260 * done output null -1 irrelevant irrelevant irrelevant
262 * Queries are only not on a queue when they are actually being processed.
263 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
264 * iff the tcp connection is in state server_ok.
266 * +------------------------+
267 * START -----> | tosend/NONE |
268 * +------------------------+
270 * too big for UDP / UDP timeout \ \ send via UDP
271 * send via TCP / more retries \ \
272 * when conn'd / desired \ \
275 * +-----------+ +-------------+
276 * | tcpw/tcpw | ________ | tosend/udpw |
277 * +-----------+ \ +-------------+
278 * | | | UDP timeout | |
281 * \ | TCP died | desired | |
283 * \ \ servers | TCP / |
284 * \ \ to try | timeout / |
286 * reply \ _| +------------------+ / reply
287 * \ | done/output FAIL | /
288 * \ +------------------+ /
291 * (..... got reply ....)
293 * need child query/ies / \ no child query
296 * +---------------+ +----------------+
297 * | childw/childw | ----------------> | done/output OK |
298 * +---------------+ children done +----------------+
302 struct query_queue { adns_query head, tail; };
305 adns_initflags iflags;
306 adns_logcallbackfn *logfn;
309 struct query_queue udpw, tcpw, childw, output;
310 adns_query forallnext;
311 int nextid, udpsocket, tcpsocket;
312 vbuf tcpsend, tcprecv;
313 int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
314 enum adns__tcpstate {
315 server_disconnected, server_connecting,
316 server_ok, server_broken
318 struct timeval tcptimeout;
319 /* This will have tv_sec==0 if it is not valid. It will always be
320 * valid if tcpstate _connecting. When _ok, it will be nonzero if
321 * we are idle (ie, tcpw queue is empty), in which case it is the
322 * absolute time when we will close the connection.
324 struct sigaction stdsigpipe;
326 struct pollfd pollfds_buf[MAX_POLLFDS];
329 } servers[MAXSERVERS];
331 struct in_addr base, mask;
332 } sortlist[MAXSORTLIST];
338 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
340 /* From general.c: */
342 void adns__vlprintf(adns_state ads, const char *fmt, va_list al);
343 void adns__lprintf(adns_state ads, const char *fmt,
344 ...) PRINTFFORMAT(2,3);
346 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
347 int serv, adns_query qu, const char *fmt, va_list al);
349 void adns__debug(adns_state ads, int serv, adns_query qu,
350 const char *fmt, ...) PRINTFFORMAT(4,5);
351 void adns__warn(adns_state ads, int serv, adns_query qu,
352 const char *fmt, ...) PRINTFFORMAT(4,5);
353 void adns__diag(adns_state ads, int serv, adns_query qu,
354 const char *fmt, ...) PRINTFFORMAT(4,5);
356 int adns__vbuf_ensure(vbuf *vb, int want);
357 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */
358 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
359 /* 1=>success, 0=>realloc failed */
360 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
361 void adns__vbuf_init(vbuf *vb);
362 void adns__vbuf_free(vbuf *vb);
364 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
366 const byte *dgram, int dglen, int cbyte);
367 /* Unpicks a domain in a datagram and returns a string suitable for
368 * printing it as. Never fails - if an error occurs, it will
369 * return some kind of string describing the error.
371 * serv may be -1 and qu may be 0. vb must have been initialised,
372 * and will be left in an arbitrary consistent state.
374 * Returns either vb->buf, or a pointer to a string literal. Do not modify
375 * vb before using the return value.
378 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
379 int (*needswap)(void *context, const void *a, const void *b),
381 /* Does an insertion sort of array which must contain nobjs objects
382 * each sz bytes long. tempbuf must point to a buffer at least
383 * sz bytes long. needswap should return !0 if a>b (strictly, ie
384 * wrong order) 0 if a<=b (ie, order is fine).
387 void adns__sigpipe_protect(adns_state);
388 void adns__sigpipe_unprotect(adns_state);
389 /* If SIGPIPE protection is not disabled, will block all signals except
390 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
391 * Each call to _protect must be followed by a call to _unprotect before
392 * any significant amount of code gets to run, since the old signal mask
393 * is stored in the adns structure.
396 /* From transmit.c: */
398 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
399 const char *owner, int ol,
400 const typeinfo *typei, adns_queryflags flags);
401 /* Assembles a query packet in vb. A new id is allocated and returned.
404 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
405 const byte *qd_dgram, int qd_dglen,
407 adns_rrtype type, adns_queryflags flags);
408 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
409 * That domain must be correct and untruncated.
412 void adns__querysend_tcp(adns_query qu, struct timeval now);
413 /* Query must be in state tcpw/tcpw; it will be sent if possible and
414 * no further processing can be done on it for now. The connection
415 * might be broken, but no reconnect will be attempted.
418 void adns__query_send(adns_query qu, struct timeval now);
419 /* Query must be in state tosend/NONE; it will be moved to a new state,
420 * and no further processing can be done on it for now.
421 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
422 * connected), tcpsent/timew, child/childw or done/output.)
423 * __query_send may decide to use either UDP or TCP depending whether
424 * _qf_usevc is set (or has become set) and whether the query is too
430 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
431 const typeinfo *typei, vbuf *qumsg_vb,
433 adns_queryflags flags, struct timeval now,
434 const qcontext *ctx);
435 /* Submits a query (for internal use, called during external submits).
437 * The new query is returned in *query_r, or we return adns_s_nomemory.
439 * The query datagram should already have been assembled in qumsg_vb;
440 * the memory for it is _taken over_ by this routine whether it
441 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
443 * *ctx is copied byte-for-byte into the query.
445 * When the child query is done, ctx->callback will be called. The
446 * child will already have been taken off both the global list of
447 * queries in ads and the list of children in the parent. The child
448 * will be freed when the callback returns. The parent will have been
449 * taken off the global childw queue.
451 * The callback should either call adns__query_done, if it is
452 * complete, or adns__query_fail, if an error has occurred, in which
453 * case the other children (if any) will be cancelled. If the parent
454 * has more unfinished children (or has just submitted more) then the
455 * callback may choose to wait for them - it must then put the parent
456 * back on the childw queue.
459 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
460 /* Walks down the searchlist for a query with adns_qf_search.
461 * The query should have just had a negative response, or not had
462 * any queries sent yet, and should not be on any queue.
463 * The query_dgram if any will be freed and forgotten and a new
464 * one constructed from the search_* members of the query.
466 * Cannot fail (in case of error, calls adns__query_fail).
469 void *adns__alloc_interim(adns_query qu, size_t sz);
470 void *adns__alloc_preserved(adns_query qu, size_t sz);
471 /* Allocates some memory, and records which query it came from
472 * and how much there was.
474 * If an error occurs in the query, all the memory from _interim is
475 * simply freed. If the query succeeds, one large buffer will be made
476 * which is big enough for all these allocations, and then
477 * adns__alloc_final will get memory from this buffer.
479 * _alloc_interim can fail (and return 0).
480 * The caller must ensure that the query is failed.
482 * The memory from _preserved is is kept and transferred into the
483 * larger buffer - unless we run out of memory, in which case it too
484 * is freed. When you use _preserved you have to add code to the
485 * x_nomem error exit case in adns__makefinal_query to clear out the
486 * pointers you made to those allocations, because that's when they're
487 * thrown away; you should also make a note in the declaration of
488 * those pointer variables, to note that they are _preserved rather
489 * than _interim. If they're in the answer, note it here:
490 * answer->cname and answer->owner are _preserved.
493 void adns__transfer_interim(adns_query from, adns_query to,
494 void *block, size_t sz);
495 /* Transfers an interim allocation from one query to another, so that
496 * the `to' query will have room for the data when we get to makefinal
497 * and so that the free will happen when the `to' query is freed
498 * rather than the `from' query.
500 * It is legal to call adns__transfer_interim with a null pointer; this
503 * _transfer_interim also ensures that the expiry time of the `to' query
504 * is no later than that of the `from' query, so that child queries'
505 * TTLs get inherited by their parents.
508 void *adns__alloc_mine(adns_query qu, size_t sz);
509 /* Like _interim, but does not record the length for later
510 * copying into the answer. This just ensures that the memory
511 * will be freed when we're done with the query.
514 void *adns__alloc_final(adns_query qu, size_t sz);
515 /* Cannot fail, and cannot return 0.
518 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
519 void adns__makefinal_str(adns_query qu, char **strp);
521 void adns__reset_preserved(adns_query qu);
522 /* Resets all of the memory management stuff etc. to take account of
523 * only the _preserved stuff from _alloc_preserved. Used when we find
524 * an error somewhere and want to just report the error (with perhaps
525 * CNAME, owner, etc. info), and also when we're halfway through RRs
526 * in a datagram and discover that we need to retry the query.
529 void adns__query_done(adns_query qu);
530 void adns__query_fail(adns_query qu, adns_status stat);
534 void adns__procdgram(adns_state ads, const byte *dgram, int len,
535 int serv, int viatcp, struct timeval now);
536 /* This function is allowed to cause new datagrams to be constructed
537 * and sent, or even new queries to be started. However,
538 * query-sending functions are not allowed to call any general event
539 * loop functions in case they accidentally call this.
541 * Ie, receiving functions may call sending functions.
542 * Sending functions may NOT call receiving functions.
547 const typeinfo *adns__findtype(adns_rrtype type);
556 int dglen, max, cbyte, namelen;
560 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
561 int serv, adns_query qu,
562 const byte *dgram, int dglen, int max,
563 int dmbegin, int *dmend_rlater);
564 /* Finds labels in a domain in a datagram.
566 * Call this routine first.
567 * dmend_rlater may be null. ads (and of course fls) may not be.
568 * serv may be -1, qu may be null - they are for error reporting.
571 adns_status adns__findlabel_next(findlabel_state *fls,
572 int *lablen_r, int *labstart_r);
573 /* Then, call this one repeatedly.
575 * It will return adns_s_ok if all is well, and tell you the length
576 * and start of successive labels. labstart_r may be null, but
577 * lablen_r must not be.
579 * After the last label, it will return with *lablen_r zero.
580 * Do not then call it again; instead, just throw away the findlabel_state.
582 * *dmend_rlater will have been set to point to the next part of
583 * the datagram after the label (or after the uncompressed part,
584 * if compression was used). *namelen_rlater will have been set
585 * to the length of the domain name (total length of labels plus
586 * 1 for each intervening dot).
588 * If the datagram appears to be truncated, *lablen_r will be -1.
589 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
590 * Do not call _next again.
592 * There may also be errors, in which case *dmend_rlater,
593 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
594 * Do not then call findlabel_next again.
601 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
602 vbuf *vb, parsedomain_flags flags,
603 const byte *dgram, int dglen, int *cbyte_io,
605 /* vb must already have been initialised; it will be reset if necessary.
606 * If there is truncation, vb->used will be set to 0; otherwise
607 * (if there is no error) vb will be null-terminated.
608 * If there is an error vb and *cbyte_io may be left indeterminate.
610 * serv may be -1 and qu may be 0 - they are used for error reporting only.
613 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
614 adns_query qu, vbuf *vb,
615 parsedomain_flags flags,
617 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
618 * for continuing an existing domain or some such of some kind. Also, unlike
619 * _parse_domain, the domain data will be appended to vb, rather than replacing
620 * the existing contents.
623 adns_status adns__findrr(adns_query qu, int serv,
624 const byte *dgram, int dglen, int *cbyte_io,
625 int *type_r, int *class_r, unsigned long *ttl_r,
626 int *rdlen_r, int *rdstart_r,
627 int *ownermatchedquery_r);
628 /* Finds the extent and some of the contents of an RR in a datagram
629 * and does some checks. The datagram is *dgram, length dglen, and
630 * the RR starts at *cbyte_io (which is updated afterwards to point
631 * to the end of the RR).
633 * The type, class, TTL and RRdata length and start are returned iff
634 * the corresponding pointer variables are not null. type_r, class_r
635 * and ttl_r may not be null. The TTL will be capped.
637 * If ownermatchedquery_r != 0 then the owner domain of this
638 * RR will be compared with that in the query (or, if the query
639 * has gone to a CNAME lookup, with the canonical name).
640 * In this case, *ownermatchedquery_r will be set to 0 or 1.
641 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
643 * If there is truncation then *type_r will be set to -1 and
644 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
647 * qu must obviously be non-null.
649 * If an error is returned then *type_r will be undefined too.
652 adns_status adns__findrr_anychk(adns_query qu, int serv,
653 const byte *dgram, int dglen, int *cbyte_io,
654 int *type_r, int *class_r,
655 unsigned long *ttl_r,
656 int *rdlen_r, int *rdstart_r,
657 const byte *eo_dgram, int eo_dglen,
658 int eo_cbyte, int *eo_matched_r);
659 /* Like adns__findrr_checked, except that the datagram and
660 * owner to compare with can be specified explicitly.
662 * If the caller thinks they know what the owner of the RR ought to
663 * be they can pass in details in eo_*: this is another (or perhaps
664 * the same datagram), and a pointer to where the putative owner
665 * starts in that datagram. In this case *eo_matched_r will be set
666 * to 1 if the datagram matched or 0 if it did not. Either
667 * both eo_dgram and eo_matched_r must both be non-null, or they
668 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
669 * The eo datagram and contained owner domain MUST be valid and
673 void adns__update_expires(adns_query qu, unsigned long ttl,
675 /* Updates the `expires' field in the query, so that it doesn't exceed
679 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
683 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
684 /* what and why may be both 0, or both non-0. */
686 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
688 void adns__autosys(adns_state ads, struct timeval now);
689 /* Make all the system calls we want to if the application wants us to.
690 * Must not be called from within adns internal processing functions,
691 * lest we end up in recursive descent !
694 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
695 struct timeval *tv_buf);
697 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
698 void adns__fdevents(adns_state ads,
699 const struct pollfd *pollfds, int npollfds,
700 int maxfd, const fd_set *readfds,
701 const fd_set *writefds, const fd_set *exceptfds,
702 struct timeval now, int *r_r);
703 int adns__internal_check(adns_state ads,
704 adns_query *query_io,
705 adns_answer **answer,
708 void adns__timeouts(adns_state ads, int act,
709 struct timeval **tv_io, struct timeval *tvbuf,
711 /* If act is !0, then this will also deal with the TCP connection
712 * if previous events broke it or require it to be connected.
717 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
719 /* Useful static inline functions: */
721 static inline int ctype_whitespace(int c) {
722 return c==' ' || c=='\n' || c=='\t';
724 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
725 static inline int ctype_alpha(int c) {
726 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
728 static inline int ctype_822special(int c) {
729 return strchr("()<>@,;:\\\".[]",c) != 0;
731 static inline int ctype_domainunquoted(int c) {
732 return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
735 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
739 #define MEM_ROUND(sz) \
740 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
741 * sizeof(union maxalign) )
743 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
744 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
745 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
746 #define GET_L(cb,tv) ( (tv)=0, \
747 (tv)|=(GETIL_B((cb))<<24), \
748 (tv)|=(GETIL_B((cb))<<16), \
749 (tv)|=(GETIL_B((cb))<<8), \