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"
73 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
90 /* Shared data structures */
111 int dglen, nsstart, nscount, arcount;
115 typedef struct typeinfo {
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,
133 int max, void *store_r);
134 /* Parse one RR, in dgram of length dglen, starting at cbyte and
135 * extending until at most max.
137 * The RR should be stored at *store_r, of length qu->typei->rrsz.
139 * If there is an overrun which might indicate truncation, it should set
140 * *rdstart to -1; otherwise it may set it to anything else positive.
142 * nsstart is the offset of the authority section.
145 int (*diff_needswap)(adns_state ads,const void *datap_a,const void *datap_b);
146 /* Returns !0 if RR a should be strictly after RR b in the sort order,
147 * 0 otherwise. Must not fail.
150 adns_status (*qdparselabel)(adns_state ads,
151 const char **p_io, const char *pe, int labelnum,
152 char label_r[DNS_MAXDOMAIN], int *ll_io,
153 adns_queryflags flags,
154 const struct typeinfo *typei);
155 /* Parses one label from the query domain string. On entry, *p_io
156 * points to the next character to parse and *ll_io is the size of
157 * the buffer. pe points just after the end of the query domain
158 * string. On successful return, label_r[] and *ll_io are filled in
159 * and *p_io points to *pe or just after the label-ending `.'. */
161 void (*postsort)(adns_state ads, void *array, int nrrs,
162 const struct typeinfo *typei);
163 /* Called immediately after the RRs have been sorted, and may rearrange
164 * them. (This is really for the benefit of SRV's bizarre weighting
165 * stuff.) May be 0 to mean nothing needs to be done.
169 adns_status adns__qdpl_normal(adns_state ads,
170 const char **p_io, const char *pe, int labelnum,
171 char label_r[], int *ll_io,
172 adns_queryflags flags,
173 const typeinfo *typei);
174 /* implemented in transmit.c, used by types.c as default
175 * and as part of implementation for some fancier types */
177 typedef struct allocnode {
178 struct allocnode *next, *back;
192 void (*callback)(adns_query parent, adns_query child);
194 adns_rr_addr ptr_parent_addr;
195 adns_rr_hostaddr *hostaddr;
201 enum { query_tosend, query_tcpw, query_childw, query_done } state;
202 adns_query back, next, parent;
203 struct { adns_query head, tail; } children;
204 struct { adns_query back, next; } siblings;
205 struct { allocnode *head, *tail; } allocations;
206 int interim_allocd, preserved_allocd;
207 void *final_allocspace;
209 const typeinfo *typei;
214 /* General-purpose messing-about buffer.
215 * Wherever a `big' interface is crossed, this may be corrupted/changed
216 * unless otherwise specified.
220 /* This is allocated when a query is submitted, to avoid being unable
221 * to relate errors to queries if we run out of memory. During
222 * query processing status, rrs is 0. cname is set if
223 * we found a cname (this corresponds to cname_dgram in the query
224 * structure). type is set from the word go. nrrs and rrs
225 * are set together, when we find how many rrs there are.
226 * owner is set during querying unless we're doing searchlist,
227 * in which case it is set only when we find an answer.
231 int cname_dglen, cname_begin;
232 /* If non-0, has been allocated using . */
235 int search_origlen, search_pos, search_doneabs;
236 /* Used by the searching algorithm. The query domain in textual form
237 * is copied into the vbuf, and _origlen set to its length. Then
238 * we walk the searchlist, if we want to. _pos says where we are
239 * (next entry to try), and _doneabs says whether we've done the
240 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
241 * but not done yet). If flags doesn't have adns_qf_search then
242 * the vbuf is initialised but empty and everything else is zero.
245 int id, flags, retries;
247 unsigned long udpsent; /* bitmap indexed by server */
248 struct timeval timeout;
249 time_t expires; /* Earliest expiry time of any record we used. */
255 * state Queue child id nextudpserver udpsent tcpfailed
257 * tosend NONE null >=0 0 zero zero
258 * tosend udpw null >=0 any nonzero zero
259 * tosend NONE null >=0 any nonzero zero
261 * tcpw tcpw null >=0 irrelevant any any
263 * child childw set >=0 irrelevant irrelevant irrelevant
264 * child NONE null >=0 irrelevant irrelevant irrelevant
265 * done output null -1 irrelevant irrelevant irrelevant
267 * Queries are only not on a queue when they are actually being processed.
268 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
269 * iff the tcp connection is in state server_ok.
271 * +------------------------+
272 * START -----> | tosend/NONE |
273 * +------------------------+
275 * too big for UDP / UDP timeout \ \ send via UDP
276 * send via TCP / more retries \ \
277 * when conn'd / desired \ \
280 * +-----------+ +-------------+
281 * | tcpw/tcpw | ________ | tosend/udpw |
282 * +-----------+ \ +-------------+
283 * | | | UDP timeout | |
286 * \ | TCP died | desired | |
288 * \ \ servers | TCP / |
289 * \ \ to try | timeout / |
291 * reply \ _| +------------------+ / reply
292 * \ | done/output FAIL | /
293 * \ +------------------+ /
296 * (..... got reply ....)
298 * need child query/ies / \ no child query
301 * +---------------+ +----------------+
302 * | childw/childw | ----------------> | done/output OK |
303 * +---------------+ children done +----------------+
307 struct query_queue { adns_query head, tail; };
310 adns_initflags iflags;
311 adns_logcallbackfn *logfn;
314 struct query_queue udpw, tcpw, childw, output;
315 adns_query forallnext;
316 int nextid, udpsocket, tcpsocket;
317 vbuf tcpsend, tcprecv;
318 int nservers, nsortlist, nsearchlist, searchndots, tcpserver, tcprecv_skip;
319 enum adns__tcpstate {
320 server_disconnected, server_connecting,
321 server_ok, server_broken
323 struct timeval tcptimeout;
324 /* This will have tv_sec==0 if it is not valid. It will always be
325 * valid if tcpstate _connecting. When _ok, it will be nonzero if
326 * we are idle (ie, tcpw queue is empty), in which case it is the
327 * absolute time when we will close the connection.
329 struct sigaction stdsigpipe;
331 struct pollfd pollfds_buf[MAX_POLLFDS];
334 } servers[MAXSERVERS];
336 struct in_addr base, mask;
337 } sortlist[MAXSORTLIST];
339 unsigned short rand48xsubi[3];
344 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
346 /* From general.c: */
348 void adns__vlprintf(adns_state ads, const char *fmt, va_list al);
349 void adns__lprintf(adns_state ads, const char *fmt,
350 ...) PRINTFFORMAT(2,3);
352 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
353 int serv, adns_query qu, const char *fmt, va_list al);
355 void adns__debug(adns_state ads, int serv, adns_query qu,
356 const char *fmt, ...) PRINTFFORMAT(4,5);
357 void adns__warn(adns_state ads, int serv, adns_query qu,
358 const char *fmt, ...) PRINTFFORMAT(4,5);
359 void adns__diag(adns_state ads, int serv, adns_query qu,
360 const char *fmt, ...) PRINTFFORMAT(4,5);
362 int adns__vbuf_ensure(vbuf *vb, int want);
363 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* doesn't include nul */
364 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
365 /* 1=>success, 0=>realloc failed */
366 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
367 void adns__vbuf_init(vbuf *vb);
368 void adns__vbuf_free(vbuf *vb);
370 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
372 const byte *dgram, int dglen, int cbyte);
373 /* Unpicks a domain in a datagram and returns a string suitable for
374 * printing it as. Never fails - if an error occurs, it will
375 * return some kind of string describing the error.
377 * serv may be -1 and qu may be 0. vb must have been initialised,
378 * and will be left in an arbitrary consistent state.
380 * Returns either vb->buf, or a pointer to a string literal. Do not modify
381 * vb before using the return value.
384 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
385 int (*needswap)(void *context, const void *a, const void *b),
387 /* Does an insertion sort of array which must contain nobjs objects
388 * each sz bytes long. tempbuf must point to a buffer at least
389 * sz bytes long. needswap should return !0 if a>b (strictly, ie
390 * wrong order) 0 if a<=b (ie, order is fine).
393 void adns__sigpipe_protect(adns_state);
394 void adns__sigpipe_unprotect(adns_state);
395 /* If SIGPIPE protection is not disabled, will block all signals except
396 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
397 * Each call to _protect must be followed by a call to _unprotect before
398 * any significant amount of code gets to run, since the old signal mask
399 * is stored in the adns structure.
402 /* From transmit.c: */
404 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
405 const char *owner, int ol,
406 const typeinfo *typei, adns_rrtype type,
407 adns_queryflags flags);
408 /* Assembles a query packet in vb. A new id is allocated and returned.
411 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
412 const byte *qd_dgram, int qd_dglen,
414 adns_rrtype type, adns_queryflags flags);
415 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
416 * That domain must be correct and untruncated.
419 void adns__querysend_tcp(adns_query qu, struct timeval now);
420 /* Query must be in state tcpw/tcpw; it will be sent if possible and
421 * no further processing can be done on it for now. The connection
422 * might be broken, but no reconnect will be attempted.
425 void adns__query_send(adns_query qu, struct timeval now);
426 /* Query must be in state tosend/NONE; it will be moved to a new state,
427 * and no further processing can be done on it for now.
428 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
429 * connected), tcpsent/timew, child/childw or done/output.)
430 * __query_send may decide to use either UDP or TCP depending whether
431 * _qf_usevc is set (or has become set) and whether the query is too
437 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
438 const typeinfo *typei, vbuf *qumsg_vb,
440 adns_queryflags flags, struct timeval now,
441 const qcontext *ctx);
442 /* Submits a query (for internal use, called during external submits).
444 * The new query is returned in *query_r, or we return adns_s_nomemory.
446 * The query datagram should already have been assembled in qumsg_vb;
447 * the memory for it is _taken over_ by this routine whether it
448 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
450 * *ctx is copied byte-for-byte into the query.
452 * When the child query is done, ctx->callback will be called. The
453 * child will already have been taken off both the global list of
454 * queries in ads and the list of children in the parent. The child
455 * will be freed when the callback returns. The parent will have been
456 * taken off the global childw queue.
458 * The callback should either call adns__query_done, if it is
459 * complete, or adns__query_fail, if an error has occurred, in which
460 * case the other children (if any) will be cancelled. If the parent
461 * has more unfinished children (or has just submitted more) then the
462 * callback may choose to wait for them - it must then put the parent
463 * back on the childw queue.
466 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
467 /* Walks down the searchlist for a query with adns_qf_search.
468 * The query should have just had a negative response, or not had
469 * any queries sent yet, and should not be on any queue.
470 * The query_dgram if any will be freed and forgotten and a new
471 * one constructed from the search_* members of the query.
473 * Cannot fail (in case of error, calls adns__query_fail).
476 void *adns__alloc_interim(adns_query qu, size_t sz);
477 void *adns__alloc_preserved(adns_query qu, size_t sz);
478 /* Allocates some memory, and records which query it came from
479 * and how much there was.
481 * If an error occurs in the query, all the memory from _interim is
482 * simply freed. If the query succeeds, one large buffer will be made
483 * which is big enough for all these allocations, and then
484 * adns__alloc_final will get memory from this buffer.
486 * _alloc_interim can fail (and return 0).
487 * The caller must ensure that the query is failed.
489 * The memory from _preserved is is kept and transferred into the
490 * larger buffer - unless we run out of memory, in which case it too
491 * is freed. When you use _preserved you have to add code to the
492 * x_nomem error exit case in adns__makefinal_query to clear out the
493 * pointers you made to those allocations, because that's when they're
494 * thrown away; you should also make a note in the declaration of
495 * those pointer variables, to note that they are _preserved rather
496 * than _interim. If they're in the answer, note it here:
497 * answer->cname and answer->owner are _preserved.
500 void adns__transfer_interim(adns_query from, adns_query to,
501 void *block, size_t sz);
502 /* Transfers an interim allocation from one query to another, so that
503 * the `to' query will have room for the data when we get to makefinal
504 * and so that the free will happen when the `to' query is freed
505 * rather than the `from' query.
507 * It is legal to call adns__transfer_interim with a null pointer; this
510 * _transfer_interim also ensures that the expiry time of the `to' query
511 * is no later than that of the `from' query, so that child queries'
512 * TTLs get inherited by their parents.
515 void *adns__alloc_mine(adns_query qu, size_t sz);
516 /* Like _interim, but does not record the length for later
517 * copying into the answer. This just ensures that the memory
518 * will be freed when we're done with the query.
521 void *adns__alloc_final(adns_query qu, size_t sz);
522 /* Cannot fail, and cannot return 0.
525 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
526 void adns__makefinal_str(adns_query qu, char **strp);
528 void adns__reset_preserved(adns_query qu);
529 /* Resets all of the memory management stuff etc. to take account of
530 * only the _preserved stuff from _alloc_preserved. Used when we find
531 * an error somewhere and want to just report the error (with perhaps
532 * CNAME, owner, etc. info), and also when we're halfway through RRs
533 * in a datagram and discover that we need to retry the query.
536 void adns__query_done(adns_query qu);
537 void adns__query_fail(adns_query qu, adns_status stat);
541 void adns__procdgram(adns_state ads, const byte *dgram, int len,
542 int serv, int viatcp, struct timeval now);
543 /* This function is allowed to cause new datagrams to be constructed
544 * and sent, or even new queries to be started. However,
545 * query-sending functions are not allowed to call any general event
546 * loop functions in case they accidentally call this.
548 * Ie, receiving functions may call sending functions.
549 * Sending functions may NOT call receiving functions.
554 const typeinfo *adns__findtype(adns_rrtype type);
563 int dglen, max, cbyte, namelen;
567 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
568 int serv, adns_query qu,
569 const byte *dgram, int dglen, int max,
570 int dmbegin, int *dmend_rlater);
571 /* Finds labels in a domain in a datagram.
573 * Call this routine first.
574 * dmend_rlater may be null. ads (and of course fls) may not be.
575 * serv may be -1, qu may be null - they are for error reporting.
578 adns_status adns__findlabel_next(findlabel_state *fls,
579 int *lablen_r, int *labstart_r);
580 /* Then, call this one repeatedly.
582 * It will return adns_s_ok if all is well, and tell you the length
583 * and start of successive labels. labstart_r may be null, but
584 * lablen_r must not be.
586 * After the last label, it will return with *lablen_r zero.
587 * Do not then call it again; instead, just throw away the findlabel_state.
589 * *dmend_rlater will have been set to point to the next part of
590 * the datagram after the label (or after the uncompressed part,
591 * if compression was used). *namelen_rlater will have been set
592 * to the length of the domain name (total length of labels plus
593 * 1 for each intervening dot).
595 * If the datagram appears to be truncated, *lablen_r will be -1.
596 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
597 * Do not call _next again.
599 * There may also be errors, in which case *dmend_rlater,
600 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
601 * Do not then call findlabel_next again.
608 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
609 vbuf *vb, parsedomain_flags flags,
610 const byte *dgram, int dglen, int *cbyte_io,
612 /* vb must already have been initialised; it will be reset if necessary.
613 * If there is truncation, vb->used will be set to 0; otherwise
614 * (if there is no error) vb will be null-terminated.
615 * If there is an error vb and *cbyte_io may be left indeterminate.
617 * serv may be -1 and qu may be 0 - they are used for error reporting only.
620 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
621 adns_query qu, vbuf *vb,
622 parsedomain_flags flags,
624 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
625 * for continuing an existing domain or some such of some kind. Also, unlike
626 * _parse_domain, the domain data will be appended to vb, rather than replacing
627 * the existing contents.
630 adns_status adns__findrr(adns_query qu, int serv,
631 const byte *dgram, int dglen, int *cbyte_io,
632 int *type_r, int *class_r, unsigned long *ttl_r,
633 int *rdlen_r, int *rdstart_r,
634 int *ownermatchedquery_r);
635 /* Finds the extent and some of the contents of an RR in a datagram
636 * and does some checks. The datagram is *dgram, length dglen, and
637 * the RR starts at *cbyte_io (which is updated afterwards to point
638 * to the end of the RR).
640 * The type, class, TTL and RRdata length and start are returned iff
641 * the corresponding pointer variables are not null. type_r, class_r
642 * and ttl_r may not be null. The TTL will be capped.
644 * If ownermatchedquery_r != 0 then the owner domain of this
645 * RR will be compared with that in the query (or, if the query
646 * has gone to a CNAME lookup, with the canonical name).
647 * In this case, *ownermatchedquery_r will be set to 0 or 1.
648 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
650 * If there is truncation then *type_r will be set to -1 and
651 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
654 * qu must obviously be non-null.
656 * If an error is returned then *type_r will be undefined too.
659 adns_status adns__findrr_anychk(adns_query qu, int serv,
660 const byte *dgram, int dglen, int *cbyte_io,
661 int *type_r, int *class_r,
662 unsigned long *ttl_r,
663 int *rdlen_r, int *rdstart_r,
664 const byte *eo_dgram, int eo_dglen,
665 int eo_cbyte, int *eo_matched_r);
666 /* Like adns__findrr_checked, except that the datagram and
667 * owner to compare with can be specified explicitly.
669 * If the caller thinks they know what the owner of the RR ought to
670 * be they can pass in details in eo_*: this is another (or perhaps
671 * the same datagram), and a pointer to where the putative owner
672 * starts in that datagram. In this case *eo_matched_r will be set
673 * to 1 if the datagram matched or 0 if it did not. Either
674 * both eo_dgram and eo_matched_r must both be non-null, or they
675 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
676 * The eo datagram and contained owner domain MUST be valid and
680 void adns__update_expires(adns_query qu, unsigned long ttl,
682 /* Updates the `expires' field in the query, so that it doesn't exceed
686 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
690 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
691 /* what and why may be both 0, or both non-0. */
693 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
695 void adns__autosys(adns_state ads, struct timeval now);
696 /* Make all the system calls we want to if the application wants us to.
697 * Must not be called from within adns internal processing functions,
698 * lest we end up in recursive descent !
701 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
702 struct timeval *tv_buf);
704 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
705 void adns__fdevents(adns_state ads,
706 const struct pollfd *pollfds, int npollfds,
707 int maxfd, const fd_set *readfds,
708 const fd_set *writefds, const fd_set *exceptfds,
709 struct timeval now, int *r_r);
710 int adns__internal_check(adns_state ads,
711 adns_query *query_io,
712 adns_answer **answer,
715 void adns__timeouts(adns_state ads, int act,
716 struct timeval **tv_io, struct timeval *tvbuf,
718 /* If act is !0, then this will also deal with the TCP connection
719 * if previous events broke it or require it to be connected.
724 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
726 /* Useful static inline functions: */
728 static inline int ctype_whitespace(int c) {
729 return c==' ' || c=='\n' || c=='\t';
731 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
732 static inline int ctype_alpha(int c) {
733 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
735 static inline int ctype_822special(int c) {
736 return strchr("()<>@,;:\\\".[]",c) != 0;
738 static inline int ctype_domainunquoted(int c) {
739 return ctype_alpha(c) || ctype_digit(c) || (strchr("-_/+",c) != 0);
742 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
746 #define MEM_ROUND(sz) \
747 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
748 * sizeof(union maxalign) )
750 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
751 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
752 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
753 #define GET_L(cb,tv) ( (tv)=0, \
754 (tv)|=(GETIL_B((cb))<<24), \
755 (tv)|=(GETIL_B((cb))<<16), \
756 (tv)|=(GETIL_B((cb))<<8), \