3 * - declarations of private objects with external linkage (adns__*)
4 * - definitons of internal macros
5 * - comments regarding library data structures
9 * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
11 * It is part of adns, which is
12 * Copyright (C) 1997-1999 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;
47 /* Configuration and constants */
50 #define MAXSORTLIST 15
51 #define UDPMAXRETRIES 15
52 #define UDPRETRYMS 2000
54 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
57 #define DNS_MAXUDP 512
58 #define DNS_MAXDOMAIN 255
59 #define DNS_HDRSIZE 12
60 #define DNS_IDOFFSET 0
61 #define DNS_CLASS_IN 1
63 #define DNS_INADDR_ARPA "in-addr", "arpa"
65 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
82 /* Shared data structures */
103 int dglen, nsstart, nscount, arcount;
113 void (*makefinal)(adns_query qu, void *data);
114 /* Change memory management of *data.
115 * Previously, used alloc_interim, now use alloc_final.
118 adns_status (*convstring)(vbuf *vb, const void *data);
119 /* Converts the RR data to a string representation in vbuf.
120 * vbuf will be appended to (it must have been initialised),
121 * and will not be null-terminated by convstring.
124 adns_status (*parse)(const parseinfo *pai, int cbyte, int max, void *store_r);
125 /* Parse one RR, in dgram of length dglen, starting at cbyte and
126 * extending until at most max.
128 * The RR should be stored at *store_r, of length qu->typei->rrsz.
130 * If there is an overrun which might indicate truncation, it should set
131 * *rdstart to -1; otherwise it may set it to anything else positive.
133 * nsstart is the offset of the authority section.
136 int (*diff_needswap)(adns_state ads, const void *datap_a, const void *datap_b);
137 /* Returns !0 if RR a should be strictly after RR b in the sort order,
138 * 0 otherwise. Must not fail.
142 typedef struct allocnode {
143 struct allocnode *next, *back;
157 void (*callback)(adns_query parent, adns_query child);
159 adns_rr_addr ptr_parent_addr;
160 adns_rr_hostaddr *hostaddr;
166 enum { query_tosend, query_tcpwait, query_tcpsent, query_child, query_done } state;
167 adns_query back, next, parent;
168 struct { adns_query head, tail; } children;
169 struct { adns_query back, next; } siblings;
170 struct { allocnode *head, *tail; } allocations;
171 int interim_allocd, preserved_allocd;
172 void *final_allocspace;
174 const typeinfo *typei;
179 /* General-purpose messing-about buffer.
180 * Wherever a `big' interface is crossed, this may be corrupted/changed
181 * unless otherwise specified.
185 /* This is allocated when a query is submitted, to avoid being unable
186 * to relate errors to queries if we run out of memory. During
187 * query processing status, rrs is 0. cname is set if
188 * we found a cname (this corresponds to cname_dgram in the query
189 * structure). type is set from the word go. nrrs and rrs
190 * are set together, when we find how many rrs there are.
191 * owner is set during querying unless we're doing searchlist,
192 * in which case it is set only when we find an answer.
196 int cname_dglen, cname_begin;
197 /* If non-0, has been allocated using . */
200 int search_origlen, search_pos, search_doneabs;
201 /* Used by the searching algorithm. The query domain in textual form
202 * is copied into the vbuf, and _origlen set to its length. Then
203 * we walk the searchlist, if we want to. _pos says where we are
204 * (next entry to try), and _doneabs says whether we've done the
205 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
206 * but not done yet). If flags doesn't have adns_qf_search then
207 * the vbuf is initialised but empty and everything else is zero.
210 int id, flags, udpretries;
212 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
213 struct timeval timeout;
214 time_t expires; /* Earliest expiry time of any record we used. */
220 * state Queue child id nextudpserver udpsent tcpfailed
222 * tosend NONE null >=0 0 zero zero
223 * tosend timew null >=0 any nonzero zero
224 * tosend NONE null >=0 any nonzero zero
226 * tcpwait timew null >=0 irrelevant any any
227 * tcpsent timew null >=0 irrelevant any any
229 * child childw set >=0 irrelevant irrelevant irrelevant
230 * child NONE null >=0 irrelevant irrelevant irrelevant
231 * done output null -1 irrelevant irrelevant irrelevant
233 * Queries are only not on a queue when they are actually being processed.
235 * +------------------------+
236 * START -----> | udp/NONE |
237 * +------------------------+
239 * too big for UDP / UDP timeout \ \ send via UDP
240 * do this ASAP! / more retries \ \ do this ASAP!
242 * +---------------+ +-----------+
243 * | tcpwait/timew | ____ | udp/timew |
244 * +---------------+ \ +-----------+
246 * TCP conn'd; | | TCP died | | |
247 * send via TCP | | more | UDP timeout | |
248 * do this ASAP! | | servers | no more | |
249 * v | to try | retries | |
250 * +---------------+ | desired | |
251 * | tcpsent/timew | ____ | | |
252 * +---------------+ \| | |
253 * \ \ TCP died | TCP | |
254 * \ \ no more | timeout / |
258 * reply \ _| +------------------+ / reply
259 * \ | done/output FAIL | /
260 * \ +------------------+ /
263 * (..... got reply ....)
265 * need child query/ies / \ no child query
268 * +--------------+ +----------------+
269 * | child/childw | ----------------> | done/output OK |
270 * +--------------+ children done +----------------+
275 adns_initflags iflags;
278 struct { adns_query head, tail; } timew, childw, output;
279 adns_query forallnext;
280 int nextid, udpsocket, tcpsocket;
281 vbuf tcpsend, tcprecv;
282 int nservers, nsortlist, nsearchlist, searchndots, tcpserver;
283 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
284 struct timeval tcptimeout;
285 struct sigaction stdsigpipe;
287 struct pollfd pollfds_buf[MAX_POLLFDS];
290 } servers[MAXSERVERS];
292 struct in_addr base, mask;
293 } sortlist[MAXSORTLIST];
299 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
300 void adns__checkqueues(adns_state ads); /* expensive walk, for checking */
302 /* From general.c: */
304 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
305 int serv, adns_query qu, const char *fmt, va_list al);
307 void adns__debug(adns_state ads, int serv, adns_query qu,
308 const char *fmt, ...) PRINTFFORMAT(4,5);
309 void adns__warn(adns_state ads, int serv, adns_query qu,
310 const char *fmt, ...) PRINTFFORMAT(4,5);
311 void adns__diag(adns_state ads, int serv, adns_query qu,
312 const char *fmt, ...) PRINTFFORMAT(4,5);
314 int adns__vbuf_ensure(vbuf *vb, int want);
315 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
316 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
317 /* 1=>success, 0=>realloc failed */
318 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
319 void adns__vbuf_init(vbuf *vb);
320 void adns__vbuf_free(vbuf *vb);
322 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
323 vbuf *vb, const byte *dgram, int dglen, int cbyte);
324 /* Unpicks a domain in a datagram and returns a string suitable for
325 * printing it as. Never fails - if an error occurs, it will
326 * return some kind of string describing the error.
328 * serv may be -1 and qu may be 0. vb must have been initialised,
329 * and will be left in an arbitrary consistent state.
331 * Returns either vb->buf, or a pointer to a string literal. Do not modify
332 * vb before using the return value.
335 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
336 int (*needswap)(void *context, const void *a, const void *b),
338 /* Does an insertion sort of array which must contain nobjs objects
339 * each sz bytes long. tempbuf must point to a buffer at least
340 * sz bytes long. needswap should return !0 if a>b (strictly, ie
341 * wrong order) 0 if a<=b (ie, order is fine).
344 void adns__sigpipe_protect(adns_state);
345 void adns__sigpipe_unprotect(adns_state);
346 /* If SIGPIPE protection is not disabled, will block all signals except
347 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
348 * Each call to _protect must be followed by a call to _unprotect before
349 * any significant amount of code gets to run.
352 /* From transmit.c: */
354 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
355 const char *owner, int ol,
356 const typeinfo *typei, adns_queryflags flags);
357 /* Assembles a query packet in vb. A new id is allocated and returned.
360 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
361 const byte *qd_dgram, int qd_dglen, int qd_begin,
362 adns_rrtype type, adns_queryflags flags);
363 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
364 * That domain must be correct and untruncated.
367 void adns__query_tcp(adns_query qu, struct timeval now);
368 /* Query must be in state tcpwait/timew; it will be moved to a new state
369 * if possible and no further processing can be done on it for now.
370 * (Resulting state is one of tcpwait/timew (if server not connected),
371 * tcpsent/timew, child/childw or done/output.)
373 * adns__tcp_tryconnect should already have been called - _tcp
374 * will only use an existing connection (if there is one), which it
375 * may break. If the conn list lost then the caller is responsible for any
376 * reestablishment and retry.
379 void adns__query_send(adns_query qu, struct timeval now);
380 /* Query must be in state tosend/NONE; it will be moved to a new state,
381 * and no further processing can be done on it for now.
382 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
383 * tcpsent/timew, child/childw or done/output.)
384 * __query_send may decide to use either UDP or TCP depending whether
385 * _qf_usevc is set (or has become set) and whether the query is too
391 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
392 const typeinfo *typei, vbuf *qumsg_vb, int id,
393 adns_queryflags flags, struct timeval now,
394 const qcontext *ctx);
395 /* Submits a query (for internal use, called during external submits).
397 * The new query is returned in *query_r, or we return adns_s_nomemory.
399 * The query datagram should already have been assembled in qumsg_vb;
400 * the memory for it is _taken over_ by this routine whether it
401 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
403 * *ctx is copied byte-for-byte into the query.
405 * When the child query is done, ctx->callback will be called. The
406 * child will already have been taken off both the global list of
407 * queries in ads and the list of children in the parent. The child
408 * will be freed when the callback returns. The parent will have been
409 * taken off the global childw queue.
411 * The callback should either call adns__query_done, if it is
412 * complete, or adns__query_fail, if an error has occurred, in which
413 * case the other children (if any) will be cancelled. If the parent
414 * has more unfinished children (or has just submitted more) then the
415 * callback may choose to wait for them - it must then put the parent
416 * back on the childw queue.
419 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
420 /* Walks down the searchlist for a query with adns_qf_search.
421 * The query should have just had a negative response, or not had
422 * any queries sent yet, and should not be on any queue.
423 * The query_dgram if any will be freed and forgotten and a new
424 * one constructed from the search_* members of the query.
426 * Cannot fail (in case of error, calls adns__query_fail).
429 void *adns__alloc_interim(adns_query qu, size_t sz);
430 void *adns__alloc_preserved(adns_query qu, size_t sz);
431 /* Allocates some memory, and records which query it came from
432 * and how much there was.
434 * If an error occurs in the query, all the memory from _interim is
435 * simply freed. If the query succeeds, one large buffer will be made
436 * which is big enough for all these allocations, and then
437 * adns__alloc_final will get memory from this buffer.
439 * _alloc_interim can fail (and return 0).
440 * The caller must ensure that the query is failed.
442 * The memory from _preserved is is kept and transferred into the
443 * larger buffer - unless we run out of memory, in which case it too
444 * is freed. When you use _preserved you have to add code to the
445 * x_nomem error exit case in adns__makefinal_query to clear out the
446 * pointers you made to those allocations, because that's when they're
447 * thrown away; you should also make a note in the declaration of
448 * those pointer variables, to note that they are _preserved rather
449 * than _interim. If they're in the answer, note it here:
450 * answer->cname and answer->owner are _preserved.
453 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
454 /* Transfers an interim allocation from one query to another, so that
455 * the `to' query will have room for the data when we get to makefinal
456 * and so that the free will happen when the `to' query is freed
457 * rather than the `from' query.
459 * It is legal to call adns__transfer_interim with a null pointer; this
462 * _transfer_interim also ensures that the expiry time of the `to' query
463 * is no later than that of the `from' query, so that child queries'
464 * TTLs get inherited by their parents.
467 void *adns__alloc_mine(adns_query qu, size_t sz);
468 /* Like _interim, but does not record the length for later
469 * copying into the answer. This just ensures that the memory
470 * will be freed when we're done with the query.
473 void *adns__alloc_final(adns_query qu, size_t sz);
474 /* Cannot fail, and cannot return 0.
477 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
478 void adns__makefinal_str(adns_query qu, char **strp);
480 void adns__reset_preserved(adns_query qu);
481 /* Resets all of the memory management stuff etc. to take account of
482 * only the _preserved stuff from _alloc_preserved. Used when we find
483 * an error somewhere and want to just report the error (with perhaps
484 * CNAME, owner, etc. info), and also when we're halfway through RRs
485 * in a datagram and discover that we need to retry the query.
488 void adns__query_done(adns_query qu);
489 void adns__query_fail(adns_query qu, adns_status stat);
493 void adns__procdgram(adns_state ads, const byte *dgram, int len,
494 int serv, int viatcp, struct timeval now);
498 const typeinfo *adns__findtype(adns_rrtype type);
507 int dglen, max, cbyte, namelen;
511 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
512 int serv, adns_query qu,
513 const byte *dgram, int dglen, int max,
514 int dmbegin, int *dmend_rlater);
515 /* Finds labels in a domain in a datagram.
517 * Call this routine first.
518 * dmend_rlater may be null. ads (and of course fls) may not be.
519 * serv may be -1, qu may be null - they are for error reporting.
522 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
523 /* Then, call this one repeatedly.
525 * It will return adns_s_ok if all is well, and tell you the length
526 * and start of successive labels. labstart_r may be null, but
527 * lablen_r must not be.
529 * After the last label, it will return with *lablen_r zero.
530 * Do not then call it again; instead, just throw away the findlabel_state.
532 * *dmend_rlater will have been set to point to the next part of
533 * the datagram after the label (or after the uncompressed part,
534 * if compression was used). *namelen_rlater will have been set
535 * to the length of the domain name (total length of labels plus
536 * 1 for each intervening dot).
538 * If the datagram appears to be truncated, *lablen_r will be -1.
539 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
540 * Do not call _next again.
542 * There may also be errors, in which case *dmend_rlater,
543 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
544 * Do not then call findlabel_next again.
551 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
552 vbuf *vb, parsedomain_flags flags,
553 const byte *dgram, int dglen, int *cbyte_io, int max);
554 /* vb must already have been initialised; it will be reset if necessary.
555 * If there is truncation, vb->used will be set to 0; otherwise
556 * (if there is no error) vb will be null-terminated.
557 * If there is an error vb and *cbyte_io may be left indeterminate.
559 * serv may be -1 and qu may be 0 - they are used for error reporting only.
562 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
563 adns_query qu, vbuf *vb, parsedomain_flags flags,
565 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
566 * for continuing an existing domain or some such of some kind. Also, unlike
567 * _parse_domain, the domain data will be appended to vb, rather than replacing
568 * the existing contents.
571 adns_status adns__findrr(adns_query qu, int serv,
572 const byte *dgram, int dglen, int *cbyte_io,
573 int *type_r, int *class_r, unsigned long *ttl_r,
574 int *rdlen_r, int *rdstart_r,
575 int *ownermatchedquery_r);
576 /* Finds the extent and some of the contents of an RR in a datagram
577 * and does some checks. The datagram is *dgram, length dglen, and
578 * the RR starts at *cbyte_io (which is updated afterwards to point
579 * to the end of the RR).
581 * The type, class, TTL and RRdata length and start are returned iff
582 * the corresponding pointer variables are not null. type_r, class_r
583 * and ttl_r may not be null. The TTL will be capped.
585 * If ownermatchedquery_r != 0 then the owner domain of this
586 * RR will be compared with that in the query (or, if the query
587 * has gone to a CNAME lookup, with the canonical name).
588 * In this case, *ownermatchedquery_r will be set to 0 or 1.
589 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
591 * If there is truncation then *type_r will be set to -1 and
592 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
595 * qu must obviously be non-null.
597 * If an error is returned then *type_r will be undefined too.
600 adns_status adns__findrr_anychk(adns_query qu, int serv,
601 const byte *dgram, int dglen, int *cbyte_io,
602 int *type_r, int *class_r, unsigned long *ttl_r,
603 int *rdlen_r, int *rdstart_r,
604 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
606 /* Like adns__findrr_checked, except that the datagram and
607 * owner to compare with can be specified explicitly.
609 * If the caller thinks they know what the owner of the RR ought to
610 * be they can pass in details in eo_*: this is another (or perhaps
611 * the same datagram), and a pointer to where the putative owner
612 * starts in that datagram. In this case *eo_matched_r will be set
613 * to 1 if the datagram matched or 0 if it did not. Either
614 * both eo_dgram and eo_matched_r must both be non-null, or they
615 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
616 * The eo datagram and contained owner domain MUST be valid and
620 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now);
621 /* Updates the `expires' field in the query, so that it doesn't exceed
625 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
629 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
630 void adns__tcp_closenext(adns_state ads);
631 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
633 void adns__autosys(adns_state ads, struct timeval now);
634 /* Make all the system calls we want to if the application wants us to. */
636 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
637 struct timeval *tv_buf);
638 void adns__timeouts(adns_state ads, int act,
639 struct timeval **tv_io, struct timeval *tvbuf,
641 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
642 void adns__fdevents(adns_state ads,
643 const struct pollfd *pollfds, int npollfds,
644 int maxfd, const fd_set *readfds,
645 const fd_set *writefds, const fd_set *exceptfds,
646 struct timeval now, int *r_r);
647 int adns__internal_check(adns_state ads,
648 adns_query *query_io,
649 adns_answer **answer,
654 void adns__consistency(adns_state ads, adns_query qu, consistency_checks cc);
656 /* Useful static inline functions: */
658 static inline void timevaladd(struct timeval *tv_io, long ms) {
662 tmp.tv_usec += (ms%1000)*1000000;
663 tmp.tv_sec += ms/1000;
664 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
668 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
669 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
670 static inline int ctype_alpha(int c) {
671 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
673 static inline int ctype_822special(int c) { return strchr("()<>@,;:\\\".[]",c) != 0; }
675 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
679 #define MEM_ROUND(sz) \
680 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
681 * sizeof(union maxalign) )
683 #define LIST_INIT(list) ((list).head= (list).tail= 0)
684 #define LINK_INIT(link) ((link).next= (link).back= 0)
686 #define LIST_UNLINK_PART(list,node,part) \
688 if ((node)->part back) (node)->part back->part next= (node)->part next; \
689 else (list).head= (node)->part next; \
690 if ((node)->part next) (node)->part next->part back= (node)->part back; \
691 else (list).tail= (node)->part back; \
694 #define LIST_LINK_TAIL_PART(list,node,part) \
696 (node)->part next= 0; \
697 (node)->part back= (list).tail; \
698 if ((list).tail) (list).tail->part next= (node); else (list).head= (node); \
699 (list).tail= (node); \
702 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
703 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
705 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
706 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
707 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
708 #define GET_L(cb,tv) ( (tv)=0, \
709 (tv)|=(GETIL_B((cb))<<24), \
710 (tv)|=(GETIL_B((cb))<<16), \
711 (tv)|=(GETIL_B((cb))<<8), \