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 Copyright (C) 1997-1999 Ian Jackson
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software Foundation,
22 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 #ifndef ADNS_INTERNAL_H_INCLUDED
26 #define ADNS_INTERNAL_H_INCLUDED
29 typedef unsigned char byte;
42 /* Configuration and constants */
45 #define MAXSORTLIST 15
46 #define UDPMAXRETRIES 15
47 #define UDPRETRYMS 2000
49 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
52 #define DNS_MAXUDP 512
53 #define DNS_MAXDOMAIN 255
54 #define DNS_HDRSIZE 12
55 #define DNS_IDOFFSET 0
56 #define DNS_CLASS_IN 1
58 #define DNS_INADDR_ARPA "in-addr", "arpa"
60 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
77 /* Shared data structures */
98 int dglen, nsstart, nscount, arcount;
108 void (*makefinal)(adns_query qu, void *data);
109 /* Change memory management of *data.
110 * Previously, used alloc_interim, now use alloc_final.
113 adns_status (*convstring)(vbuf *vb, const void *data);
114 /* Converts the RR data to a string representation in vbuf.
115 * vbuf will be appended to (it must have been initialised),
116 * and will not be null-terminated by convstring.
119 adns_status (*parse)(const parseinfo *pai, int cbyte, int max, void *store_r);
120 /* Parse one RR, in dgram of length dglen, starting at cbyte and
121 * extending until at most max.
123 * The RR should be stored at *store_r, of length qu->typei->rrsz.
125 * If there is an overrun which might indicate truncation, it should set
126 * *rdstart to -1; otherwise it may set it to anything else positive.
128 * nsstart is the offset of the authority section.
131 int (*diff_needswap)(adns_state ads, const void *datap_a, const void *datap_b);
132 /* Returns !0 if RR a should be strictly after RR b in the sort order,
133 * 0 otherwise. Must not fail.
137 typedef struct allocnode {
138 struct allocnode *next, *back;
152 void (*callback)(adns_query parent, adns_query child);
154 adns_rr_addr ptr_parent_addr;
155 adns_rr_hostaddr *hostaddr;
161 enum { query_tosend, query_tcpwait, query_tcpsent, query_child, query_done } state;
162 adns_query back, next, parent;
163 struct { adns_query head, tail; } children;
164 struct { adns_query back, next; } siblings;
165 struct { allocnode *head, *tail; } allocations;
166 int interim_allocd, preserved_allocd;
167 void *final_allocspace;
169 const typeinfo *typei;
174 /* General-purpose messing-about buffer.
175 * Wherever a `big' interface is crossed, this may be corrupted/changed
176 * unless otherwise specified.
180 /* This is allocated when a query is submitted, to avoid being unable
181 * to relate errors to queries if we run out of memory. During
182 * query processing status, rrs is 0. cname is set if
183 * we found a cname (this corresponds to cname_dgram in the query
184 * structure). type is set from the word go. nrrs and rrs
185 * are set together, when we find how many rrs there are.
186 * owner is set during querying unless we're doing searchlist,
187 * in which case it is set only when we find an answer.
191 int cname_dglen, cname_begin;
192 /* If non-0, has been allocated using . */
195 int search_origlen, search_pos, search_doneabs;
196 /* Used by the searching algorithm. The query domain in textual form
197 * is copied into the vbuf, and _origlen set to its length. Then
198 * we walk the searchlist, if we want to. _pos says where we are
199 * (next entry to try), and _doneabs says whether we've done the
200 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
201 * but not done yet). If flags doesn't have adns_qf_search then
202 * the vbuf is initialised but empty and everything else is zero.
205 int id, flags, udpretries;
207 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
208 struct timeval timeout;
209 time_t expires; /* Earliest expiry time of any record we used. */
215 * state Queue child id nextudpserver udpsent tcpfailed
217 * tosend NONE null >=0 0 zero zero
218 * tosend timew null >=0 any nonzero zero
219 * tosend NONE null >=0 any nonzero zero
221 * tcpwait timew null >=0 irrelevant any any
222 * tcpsent timew null >=0 irrelevant any any
224 * child childw set >=0 irrelevant irrelevant irrelevant
225 * child NONE null >=0 irrelevant irrelevant irrelevant
226 * done output null -1 irrelevant irrelevant irrelevant
228 * Queries are only not on a queue when they are actually being processed.
230 * +------------------------+
231 * START -----> | udp/NONE |
232 * +------------------------+
234 * too big for UDP / UDP timeout \ \ send via UDP
235 * do this ASAP! / more retries \ \ do this ASAP!
237 * +---------------+ +-----------+
238 * | tcpwait/timew | ____ | udp/timew |
239 * +---------------+ \ +-----------+
241 * TCP conn'd; | | TCP died | | |
242 * send via TCP | | more | UDP timeout | |
243 * do this ASAP! | | servers | no more | |
244 * v | to try | retries | |
245 * +---------------+ | desired | |
246 * | tcpsent/timew | ____ | | |
247 * +---------------+ \| | |
248 * \ \ TCP died | TCP | |
249 * \ \ no more | timeout / |
253 * reply \ _| +------------------+ / reply
254 * \ | done/output FAIL | /
255 * \ +------------------+ /
258 * (..... got reply ....)
260 * need child query/ies / \ no child query
263 * +--------------+ +----------------+
264 * | child/childw | ----------------> | done/output OK |
265 * +--------------+ children done +----------------+
270 adns_initflags iflags;
273 struct { adns_query head, tail; } timew, childw, output;
274 adns_query forallnext;
275 int nextid, udpsocket, tcpsocket;
276 vbuf tcpsend, tcprecv;
277 int nservers, nsortlist, nsearchlist, searchndots, tcpserver;
278 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
279 struct timeval tcptimeout;
280 struct sigaction stdsigpipe;
282 struct pollfd pollfds_buf[MAX_POLLFDS];
285 } servers[MAXSERVERS];
287 struct in_addr base, mask;
288 } sortlist[MAXSORTLIST];
294 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
295 void adns__checkqueues(adns_state ads); /* expensive walk, for checking */
297 /* From general.c: */
299 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
300 int serv, adns_query qu, const char *fmt, va_list al);
302 void adns__debug(adns_state ads, int serv, adns_query qu,
303 const char *fmt, ...) PRINTFFORMAT(4,5);
304 void adns__warn(adns_state ads, int serv, adns_query qu,
305 const char *fmt, ...) PRINTFFORMAT(4,5);
306 void adns__diag(adns_state ads, int serv, adns_query qu,
307 const char *fmt, ...) PRINTFFORMAT(4,5);
309 int adns__vbuf_ensure(vbuf *vb, int want);
310 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
311 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
312 /* 1=>success, 0=>realloc failed */
313 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
314 void adns__vbuf_init(vbuf *vb);
315 void adns__vbuf_free(vbuf *vb);
317 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
318 vbuf *vb, const byte *dgram, int dglen, int cbyte);
319 /* Unpicks a domain in a datagram and returns a string suitable for
320 * printing it as. Never fails - if an error occurs, it will
321 * return some kind of string describing the error.
323 * serv may be -1 and qu may be 0. vb must have been initialised,
324 * and will be left in an arbitrary consistent state.
326 * Returns either vb->buf, or a pointer to a string literal. Do not modify
327 * vb before using the return value.
330 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
331 int (*needswap)(void *context, const void *a, const void *b),
333 /* Does an insertion sort of array which must contain nobjs objects
334 * each sz bytes long. tempbuf must point to a buffer at least
335 * sz bytes long. needswap should return !0 if a>b (strictly, ie
336 * wrong order) 0 if a<=b (ie, order is fine).
339 void adns__sigpipe_protect(adns_state);
340 void adns__sigpipe_unprotect(adns_state);
341 /* If SIGPIPE protection is not disabled, will block all signals except
342 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
343 * Each call to _protect must be followed by a call to _unprotect before
344 * any significant amount of code gets to run.
347 /* From transmit.c: */
349 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
350 const char *owner, int ol,
351 const typeinfo *typei, adns_queryflags flags);
352 /* Assembles a query packet in vb. A new id is allocated and returned.
355 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
356 const byte *qd_dgram, int qd_dglen, int qd_begin,
357 adns_rrtype type, adns_queryflags flags);
358 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
359 * That domain must be correct and untruncated.
362 void adns__query_tcp(adns_query qu, struct timeval now);
363 /* Query must be in state tcpwait/timew; it will be moved to a new state
364 * if possible and no further processing can be done on it for now.
365 * (Resulting state is one of tcpwait/timew (if server not connected),
366 * tcpsent/timew, child/childw or done/output.)
368 * adns__tcp_tryconnect should already have been called - _tcp
369 * will only use an existing connection (if there is one), which it
370 * may break. If the conn list lost then the caller is responsible for any
371 * reestablishment and retry.
374 void adns__query_send(adns_query qu, struct timeval now);
375 /* Query must be in state tosend/NONE; it will be moved to a new state,
376 * and no further processing can be done on it for now.
377 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
378 * tcpsent/timew, child/childw or done/output.)
379 * __query_send may decide to use either UDP or TCP depending whether
380 * _qf_usevc is set (or has become set) and whether the query is too
386 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
387 const typeinfo *typei, vbuf *qumsg_vb, int id,
388 adns_queryflags flags, struct timeval now,
389 const qcontext *ctx);
390 /* Submits a query (for internal use, called during external submits).
392 * The new query is returned in *query_r, or we return adns_s_nomemory.
394 * The query datagram should already have been assembled in qumsg_vb;
395 * the memory for it is _taken over_ by this routine whether it
396 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
398 * *ctx is copied byte-for-byte into the query.
400 * When the child query is done, ctx->callback will be called. The
401 * child will already have been taken off both the global list of
402 * queries in ads and the list of children in the parent. The child
403 * will be freed when the callback returns. The parent will have been
404 * taken off the global childw queue.
406 * The callback should either call adns__query_done, if it is
407 * complete, or adns__query_fail, if an error has occurred, in which
408 * case the other children (if any) will be cancelled. If the parent
409 * has more unfinished children (or has just submitted more) then the
410 * callback may choose to wait for them - it must then put the parent
411 * back on the childw queue.
414 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
415 /* Walks down the searchlist for a query with adns_qf_search.
416 * The query should have just had a negative response, or not had
417 * any queries sent yet, and should not be on any queue.
418 * The query_dgram if any will be freed and forgotten and a new
419 * one constructed from the search_* members of the query.
421 * Cannot fail (in case of error, calls adns__query_fail).
424 void *adns__alloc_interim(adns_query qu, size_t sz);
425 void *adns__alloc_preserved(adns_query qu, size_t sz);
426 /* Allocates some memory, and records which query it came from
427 * and how much there was.
429 * If an error occurs in the query, all the memory from _interim is
430 * simply freed. If the query succeeds, one large buffer will be made
431 * which is big enough for all these allocations, and then
432 * adns__alloc_final will get memory from this buffer.
434 * _alloc_interim can fail (and return 0).
435 * The caller must ensure that the query is failed.
437 * The memory from _preserved is is kept and transferred into the
438 * larger buffer - unless we run out of memory, in which case it too
439 * is freed. When you use _preserved you have to add code to the
440 * x_nomem error exit case in adns__makefinal_query to clear out the
441 * pointers you made to those allocations, because that's when they're
442 * thrown away; you should also make a note in the declaration of
443 * those pointer variables, to note that they are _preserved rather
444 * than _interim. If they're in the answer, note it here:
445 * answer->cname and answer->owner are _preserved.
448 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
449 /* Transfers an interim allocation from one query to another, so that
450 * the `to' query will have room for the data when we get to makefinal
451 * and so that the free will happen when the `to' query is freed
452 * rather than the `from' query.
454 * It is legal to call adns__transfer_interim with a null pointer; this
457 * _transfer_interim also ensures that the expiry time of the `to' query
458 * is no later than that of the `from' query, so that child queries'
459 * TTLs get inherited by their parents.
462 void *adns__alloc_mine(adns_query qu, size_t sz);
463 /* Like _interim, but does not record the length for later
464 * copying into the answer. This just ensures that the memory
465 * will be freed when we're done with the query.
468 void *adns__alloc_final(adns_query qu, size_t sz);
469 /* Cannot fail, and cannot return 0.
472 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
473 void adns__makefinal_str(adns_query qu, char **strp);
475 void adns__reset_preserved(adns_query qu);
476 /* Resets all of the memory management stuff etc. to take account of
477 * only the _preserved stuff from _alloc_preserved. Used when we find
478 * an error somewhere and want to just report the error (with perhaps
479 * CNAME, owner, etc. info), and also when we're halfway through RRs
480 * in a datagram and discover that we need to retry the query.
483 void adns__query_done(adns_query qu);
484 void adns__query_fail(adns_query qu, adns_status stat);
488 void adns__procdgram(adns_state ads, const byte *dgram, int len,
489 int serv, int viatcp, struct timeval now);
493 const typeinfo *adns__findtype(adns_rrtype type);
502 int dglen, max, cbyte, namelen;
506 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
507 int serv, adns_query qu,
508 const byte *dgram, int dglen, int max,
509 int dmbegin, int *dmend_rlater);
510 /* Finds labels in a domain in a datagram.
512 * Call this routine first.
513 * dmend_rlater may be null. ads (and of course fls) may not be.
514 * serv may be -1, qu may be null - they are for error reporting.
517 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
518 /* Then, call this one repeatedly.
520 * It will return adns_s_ok if all is well, and tell you the length
521 * and start of successive labels. labstart_r may be null, but
522 * lablen_r must not be.
524 * After the last label, it will return with *lablen_r zero.
525 * Do not then call it again; instead, just throw away the findlabel_state.
527 * *dmend_rlater will have been set to point to the next part of
528 * the datagram after the label (or after the uncompressed part,
529 * if compression was used). *namelen_rlater will have been set
530 * to the length of the domain name (total length of labels plus
531 * 1 for each intervening dot).
533 * If the datagram appears to be truncated, *lablen_r will be -1.
534 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
535 * Do not call _next again.
537 * There may also be errors, in which case *dmend_rlater,
538 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
539 * Do not then call findlabel_next again.
546 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
547 vbuf *vb, parsedomain_flags flags,
548 const byte *dgram, int dglen, int *cbyte_io, int max);
549 /* vb must already have been initialised; it will be reset if necessary.
550 * If there is truncation, vb->used will be set to 0; otherwise
551 * (if there is no error) vb will be null-terminated.
552 * If there is an error vb and *cbyte_io may be left indeterminate.
554 * serv may be -1 and qu may be 0 - they are used for error reporting only.
557 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
558 adns_query qu, vbuf *vb, parsedomain_flags flags,
560 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
561 * for continuing an existing domain or some such of some kind. Also, unlike
562 * _parse_domain, the domain data will be appended to vb, rather than replacing
563 * the existing contents.
566 adns_status adns__findrr(adns_query qu, int serv,
567 const byte *dgram, int dglen, int *cbyte_io,
568 int *type_r, int *class_r, unsigned long *ttl_r,
569 int *rdlen_r, int *rdstart_r,
570 int *ownermatchedquery_r);
571 /* Finds the extent and some of the contents of an RR in a datagram
572 * and does some checks. The datagram is *dgram, length dglen, and
573 * the RR starts at *cbyte_io (which is updated afterwards to point
574 * to the end of the RR).
576 * The type, class, TTL and RRdata length and start are returned iff
577 * the corresponding pointer variables are not null. type_r, class_r
578 * and ttl_r may not be null. The TTL will be capped.
580 * If ownermatchedquery_r != 0 then the owner domain of this
581 * RR will be compared with that in the query (or, if the query
582 * has gone to a CNAME lookup, with the canonical name).
583 * In this case, *ownermatchedquery_r will be set to 0 or 1.
584 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
586 * If there is truncation then *type_r will be set to -1 and
587 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
590 * qu must obviously be non-null.
592 * If an error is returned then *type_r will be undefined too.
595 adns_status adns__findrr_anychk(adns_query qu, int serv,
596 const byte *dgram, int dglen, int *cbyte_io,
597 int *type_r, int *class_r, unsigned long *ttl_r,
598 int *rdlen_r, int *rdstart_r,
599 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
601 /* Like adns__findrr_checked, except that the datagram and
602 * owner to compare with can be specified explicitly.
604 * If the caller thinks they know what the owner of the RR ought to
605 * be they can pass in details in eo_*: this is another (or perhaps
606 * the same datagram), and a pointer to where the putative owner
607 * starts in that datagram. In this case *eo_matched_r will be set
608 * to 1 if the datagram matched or 0 if it did not. Either
609 * both eo_dgram and eo_matched_r must both be non-null, or they
610 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
611 * The eo datagram and contained owner domain MUST be valid and
615 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now);
616 /* Updates the `expires' field in the query, so that it doesn't exceed
620 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
624 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
625 void adns__tcp_closenext(adns_state ads);
626 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
628 void adns__autosys(adns_state ads, struct timeval now);
629 /* Make all the system calls we want to if the application wants us to. */
631 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
632 struct timeval *tv_buf);
633 void adns__timeouts(adns_state ads, int act,
634 struct timeval **tv_io, struct timeval *tvbuf,
636 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
637 void adns__fdevents(adns_state ads,
638 const struct pollfd *pollfds, int npollfds,
639 int maxfd, const fd_set *readfds,
640 const fd_set *writefds, const fd_set *exceptfds,
641 struct timeval now, int *r_r);
642 int adns__internal_check(adns_state ads,
643 adns_query *query_io,
644 adns_answer **answer,
649 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
651 /* Useful static inline functions: */
653 static inline void timevaladd(struct timeval *tv_io, long ms) {
657 tmp.tv_usec += (ms%1000)*1000000;
658 tmp.tv_sec += ms/1000;
659 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
663 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
664 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
665 static inline int ctype_alpha(int c) {
666 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
668 static inline int ctype_822special(int c) { return strchr("()<>@,;:\\\".[]",c) != 0; }
670 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
674 #define MEM_ROUND(sz) \
675 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
676 * sizeof(union maxalign) )
678 #define LIST_INIT(list) ((list).head= (list).tail= 0)
679 #define LINK_INIT(link) ((link).next= (link).back= 0)
681 #define LIST_UNLINK_PART(list,node,part) \
683 if ((node)->part back) (node)->part back->part next= (node)->part next; \
684 else (list).head= (node)->part next; \
685 if ((node)->part next) (node)->part next->part back= (node)->part back; \
686 else (list).tail= (node)->part back; \
689 #define LIST_LINK_TAIL_PART(list,node,part) \
691 (node)->part next= 0; \
692 (node)->part back= (list).tail; \
693 if ((list).tail) (list).tail->part next= (node); else (list).head= (node); \
694 (list).tail= (node); \
697 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
698 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
700 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
701 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
702 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
703 #define GET_L(cb,tv) ( (tv)=0, \
704 (tv)|=(GETIL_B((cb))<<24), \
705 (tv)|=(GETIL_B((cb))<<16), \
706 (tv)|=(GETIL_B((cb))<<8), \