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;
41 /* Configuration and constants */
44 #define MAXSORTLIST 15
45 #define UDPMAXRETRIES 15
46 #define UDPRETRYMS 2000
48 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
51 #define DNS_MAXUDP 512
52 #define DNS_MAXDOMAIN 255
53 #define DNS_HDRSIZE 12
54 #define DNS_IDOFFSET 0
55 #define DNS_CLASS_IN 1
57 #define DNS_INADDR_ARPA "in-addr", "arpa"
59 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
70 /* Shared data structures */
91 int dglen, nsstart, nscount, arcount;
101 void (*makefinal)(adns_query qu, void *data);
102 /* Change memory management of *data.
103 * Previously, used alloc_interim, now use alloc_final.
106 adns_status (*convstring)(vbuf *vb, const void *data);
107 /* Converts the RR data to a string representation in vbuf.
108 * vbuf will be appended to (it must have been initialised),
109 * and will not be null-terminated by convstring.
112 adns_status (*parse)(const parseinfo *pai, int cbyte, int max, void *store_r);
113 /* Parse one RR, in dgram of length dglen, starting at cbyte and
114 * extending until at most max.
116 * The RR should be stored at *store_r, of length qu->typei->rrsz.
118 * If there is an overrun which might indicate truncation, it should set
119 * *rdstart to -1; otherwise it may set it to anything else positive.
121 * nsstart is the offset of the authority section.
124 int (*diff_needswap)(adns_state ads, const void *datap_a, const void *datap_b);
125 /* Returns !0 if RR a should be strictly after RR b in the sort order,
126 * 0 otherwise. Must not fail.
130 typedef struct allocnode {
131 struct allocnode *next, *back;
145 void (*callback)(adns_query parent, adns_query child);
147 adns_rr_addr ptr_parent_addr;
148 adns_rr_hostaddr *hostaddr;
154 enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
155 adns_query back, next, parent;
156 struct { adns_query head, tail; } children;
157 struct { adns_query back, next; } siblings;
158 struct { allocnode *head, *tail; } allocations;
159 int interim_allocd, preserved_allocd;
160 void *final_allocspace;
162 const typeinfo *typei;
167 /* General-purpose messing-about buffer.
168 * Wherever a `big' interface is crossed, this may be corrupted/changed
169 * unless otherwise specified.
173 /* This is allocated when a query is submitted, to avoid being unable
174 * to relate errors to queries if we run out of memory. During
175 * query processing status, rrs is 0. cname is set if
176 * we found a cname (this corresponds to cname_dgram in the query
177 * structure). type is set from the word go. nrrs and rrs
178 * are set together, when we find how many rrs there are.
179 * owner is set during querying unless we're doing searchlist,
180 * in which case it is set only when we find an answer.
184 int cname_dglen, cname_begin;
185 /* If non-0, has been allocated using . */
188 int search_origlen, search_pos, search_doneabs;
189 /* Used by the searching algorithm. The query domain in textual form
190 * is copied into the vbuf, and _origlen set to its length. Then
191 * we walk the searchlist, if we want to. _pos says where we are
192 * (next entry to try), and _doneabs says whether we've done the
193 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
194 * but not done yet). If flags doesn't have adns_qf_search then
195 * the vbuf is initialised but empty and everything else is zero.
198 int id, flags, udpretries;
200 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
201 struct timeval timeout;
202 time_t expires; /* Earliest expiry time of any record we used. */
208 * state Queue child id nextudpserver sentudp failedtcp
210 * udp NONE null >=0 0 zero zero
211 * udp timew null >=0 any nonzero zero
212 * udp NONE null >=0 any nonzero zero
214 * tcpwait timew null >=0 irrelevant zero any
215 * tcpsent timew null >=0 irrelevant zero any
217 * child childw set >=0 irrelevant irrelevant irrelevant
218 * child NONE null >=0 irrelevant irrelevant irrelevant
219 * done output null -1 irrelevant irrelevant irrelevant
221 * Queries are only not on a queue when they are actually being processed.
223 * +------------------------+
224 * START -----> | udp/NONE |
225 * +------------------------+
227 * too big for UDP / UDP timeout \ \ send via UDP
228 * do this ASAP! / more retries \ \ do this ASAP!
230 * +---------------+ +-----------+
231 * | tcpwait/timew | ____ | udp/timew |
232 * +---------------+ \ +-----------+
234 * TCP conn'd; | | TCP died | | |
235 * send via TCP | | more | UDP timeout | |
236 * do this ASAP! | | servers | no more | |
237 * v | to try | retries | |
238 * +---------------+ | desired | |
239 * | tcpsent/timew | ____ | | |
240 * +---------------+ \| | |
241 * \ \ TCP died | TCP | |
242 * \ \ no more | timeout / |
246 * reply \ _| +------------------+ / reply
247 * \ | done/output FAIL | /
248 * \ +------------------+ /
251 * (..... got reply ....)
253 * need child query/ies / \ no child query
256 * +--------------+ +----------------+
257 * | child/childw | ----------------> | done/output OK |
258 * +--------------+ children done +----------------+
263 adns_initflags iflags;
266 struct { adns_query head, tail; } timew, childw, output;
267 adns_query forallnext;
268 int nextid, udpsocket, tcpsocket;
269 vbuf tcpsend, tcprecv;
270 int nservers, nsortlist, nsearchlist, searchndots, tcpserver;
271 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
272 struct timeval tcptimeout;
273 struct sigaction stdsigpipe;
275 struct pollfd pollfds_buf[MAX_POLLFDS];
278 } servers[MAXSERVERS];
280 struct in_addr base, mask;
281 } sortlist[MAXSORTLIST];
287 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
289 /* From general.c: */
291 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
292 int serv, adns_query qu, const char *fmt, va_list al);
294 void adns__debug(adns_state ads, int serv, adns_query qu,
295 const char *fmt, ...) PRINTFFORMAT(4,5);
296 void adns__warn(adns_state ads, int serv, adns_query qu,
297 const char *fmt, ...) PRINTFFORMAT(4,5);
298 void adns__diag(adns_state ads, int serv, adns_query qu,
299 const char *fmt, ...) PRINTFFORMAT(4,5);
301 int adns__vbuf_ensure(vbuf *vb, int want);
302 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
303 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
304 /* 1=>success, 0=>realloc failed */
305 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
306 void adns__vbuf_init(vbuf *vb);
307 void adns__vbuf_free(vbuf *vb);
309 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
310 vbuf *vb, const byte *dgram, int dglen, int cbyte);
311 /* Unpicks a domain in a datagram and returns a string suitable for
312 * printing it as. Never fails - if an error occurs, it will
313 * return some kind of string describing the error.
315 * serv may be -1 and qu may be 0. vb must have been initialised,
316 * and will be left in an arbitrary consistent state.
318 * Returns either vb->buf, or a pointer to a string literal. Do not modify
319 * vb before using the return value.
322 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
323 int (*needswap)(void *context, const void *a, const void *b),
325 /* Does an insertion sort of array which must contain nobjs objects
326 * each sz bytes long. tempbuf must point to a buffer at least
327 * sz bytes long. needswap should return !0 if a>b (strictly, ie
328 * wrong order) 0 if a<=b (ie, order is fine).
331 void adns__sigpipe_protect(adns_state);
332 void adns__sigpipe_unprotect(adns_state);
333 /* If SIGPIPE protection is not disabled, will block all signals except
334 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
335 * Each call to _protect must be followed by a call to _unprotect before
336 * any significant amount of code gets to run.
339 /* From transmit.c: */
341 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
342 const char *owner, int ol,
343 const typeinfo *typei, adns_queryflags flags);
344 /* Assembles a query packet in vb. A new id is allocated and returned.
347 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
348 const byte *qd_dgram, int qd_dglen, int qd_begin,
349 adns_rrtype type, adns_queryflags flags);
350 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
351 * That domain must be correct and untruncated.
354 void adns__query_tcp(adns_query qu, struct timeval now);
355 /* Query must be in state tcpwait/timew; it will be moved to a new state
356 * if possible and no further processing can be done on it for now.
357 * (Resulting state is one of tcpwait/timew (if server not connected),
358 * tcpsent/timew, child/childw or done/output.)
360 * adns__tcp_tryconnect should already have been called - _tcp
361 * will only use an existing connection (if there is one), which it
362 * may break. If the conn list lost then the caller is responsible for any
363 * reestablishment and retry.
366 void adns__query_udp(adns_query qu, struct timeval now);
367 /* Query must be in state udp/NONE; it will be moved to a new state,
368 * and no further processing can be done on it for now.
369 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
370 * tcpsent/timew, child/childw or done/output.)
375 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
376 const typeinfo *typei, vbuf *qumsg_vb, int id,
377 adns_queryflags flags, struct timeval now,
378 const qcontext *ctx);
379 /* Submits a query (for internal use, called during external submits).
381 * The new query is returned in *query_r, or we return adns_s_nomemory.
383 * The query datagram should already have been assembled in qumsg_vb;
384 * the memory for it is _taken over_ by this routine whether it
385 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
387 * *ctx is copied byte-for-byte into the query.
389 * When the child query is done, ctx->callback will be called. The
390 * child will already have been taken off both the global list of
391 * queries in ads and the list of children in the parent. The child
392 * will be freed when the callback returns. The parent will have been
393 * taken off the global childw queue iff this is the last child for
394 * that parent. If there is no error detected in the callback, then
395 * it should call adns__query_done if and only if there are no more
396 * children (by checking parent->children.head). If an error is
397 * detected in the callback it should call adns__query_fail and any
398 * remaining children will automatically be cancelled.
401 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
402 /* Walks down the searchlist for a query with adns_qf_search.
403 * The query should have just had a negative response, or not had
404 * any queries sent yet, and should not be on any queue.
405 * The query_dgram if any will be freed and forgotten and a new
406 * one constructed from the search_* members of the query.
408 * Cannot fail (in case of error, calls adns__query_fail).
411 void *adns__alloc_interim(adns_query qu, size_t sz);
412 void *adns__alloc_preserved(adns_query qu, size_t sz);
413 /* Allocates some memory, and records which query it came from
414 * and how much there was.
416 * If an error occurs in the query, all the memory from _interim is
417 * simply freed. If the query succeeds, one large buffer will be made
418 * which is big enough for all these allocations, and then
419 * adns__alloc_final will get memory from this buffer.
421 * _alloc_interim can fail (and return 0).
422 * The caller must ensure that the query is failed.
424 * The memory from _preserved is is kept and transferred into the
425 * larger buffer - unless we run out of memory, in which case it too
426 * is freed. When you use _preserved you have to add code to the
427 * x_nomem error exit case in adns__makefinal_query to clear out the
428 * pointers you made to those allocations, because that's when they're
429 * thrown away; you should also make a note in the declaration of
430 * those pointer variables, to note that they are _preserved rather
431 * than _interim. If they're in the answer, note it here:
432 * answer->cname and answer->owner are _preserved.
435 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
436 /* Transfers an interim allocation from one query to another, so that
437 * the `to' query will have room for the data when we get to makefinal
438 * and so that the free will happen when the `to' query is freed
439 * rather than the `from' query.
441 * It is legal to call adns__transfer_interim with a null pointer; this
444 * _transfer_interim also ensures that the expiry time of the `to' query
445 * is no later than that of the `from' query, so that child queries'
446 * TTLs get inherited by their parents.
449 void *adns__alloc_mine(adns_query qu, size_t sz);
450 /* Like _interim, but does not record the length for later
451 * copying into the answer. This just ensures that the memory
452 * will be freed when we're done with the query.
455 void *adns__alloc_final(adns_query qu, size_t sz);
456 /* Cannot fail, and cannot return 0.
459 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
460 void adns__makefinal_str(adns_query qu, char **strp);
462 void adns__reset_preserved(adns_query qu);
463 /* Resets all of the memory management stuff etc. to take account of
464 * only the _preserved stuff from _alloc_preserved. Used when we find
465 * an error somewhere and want to just report the error (with perhaps
466 * CNAME, owner, etc. info), and also when we're halfway through RRs
467 * in a datagram and discover that we need to retry the query.
470 void adns__query_done(adns_query qu);
471 void adns__query_fail(adns_query qu, adns_status stat);
475 void adns__procdgram(adns_state ads, const byte *dgram, int len,
476 int serv, struct timeval now);
480 const typeinfo *adns__findtype(adns_rrtype type);
489 int dglen, max, cbyte, namelen;
493 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
494 int serv, adns_query qu,
495 const byte *dgram, int dglen, int max,
496 int dmbegin, int *dmend_rlater);
497 /* Finds labels in a domain in a datagram.
499 * Call this routine first.
500 * dmend_rlater may be null. ads (and of course fls) may not be.
501 * serv may be -1, qu may be null - they are for error reporting.
504 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
505 /* Then, call this one repeatedly.
507 * It will return adns_s_ok if all is well, and tell you the length
508 * and start of successive labels. labstart_r may be null, but
509 * lablen_r must not be.
511 * After the last label, it will return with *lablen_r zero.
512 * Do not then call it again; instead, just throw away the findlabel_state.
514 * *dmend_rlater will have been set to point to the next part of
515 * the datagram after the label (or after the uncompressed part,
516 * if compression was used). *namelen_rlater will have been set
517 * to the length of the domain name (total length of labels plus
518 * 1 for each intervening dot).
520 * If the datagram appears to be truncated, *lablen_r will be -1.
521 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
522 * Do not call _next again.
524 * There may also be errors, in which case *dmend_rlater,
525 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
526 * Do not then call findlabel_next again.
533 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
534 vbuf *vb, parsedomain_flags flags,
535 const byte *dgram, int dglen, int *cbyte_io, int max);
536 /* vb must already have been initialised; it will be reset if necessary.
537 * If there is truncation, vb->used will be set to 0; otherwise
538 * (if there is no error) vb will be null-terminated.
539 * If there is an error vb and *cbyte_io may be left indeterminate.
541 * serv may be -1 and qu may be 0 - they are used for error reporting only.
544 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
545 adns_query qu, vbuf *vb, parsedomain_flags flags,
547 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
548 * for continuing an existing domain or some such of some kind. Also, unlike
549 * _parse_domain, the domain data will be appended to vb, rather than replacing
550 * the existing contents.
553 adns_status adns__findrr(adns_query qu, int serv,
554 const byte *dgram, int dglen, int *cbyte_io,
555 int *type_r, int *class_r, unsigned long *ttl_r,
556 int *rdlen_r, int *rdstart_r,
557 int *ownermatchedquery_r);
558 /* Finds the extent and some of the contents of an RR in a datagram
559 * and does some checks. The datagram is *dgram, length dglen, and
560 * the RR starts at *cbyte_io (which is updated afterwards to point
561 * to the end of the RR).
563 * The type, class, TTL and RRdata length and start are returned iff
564 * the corresponding pointer variables are not null. type_r, class_r
565 * and ttl_r may not be null. The TTL will be capped.
567 * If ownermatchedquery_r != 0 then the owner domain of this
568 * RR will be compared with that in the query (or, if the query
569 * has gone to a CNAME lookup, with the canonical name).
570 * In this case, *ownermatchedquery_r will be set to 0 or 1.
571 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
573 * If there is truncation then *type_r will be set to -1 and
574 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
577 * qu must obviously be non-null.
579 * If an error is returned then *type_r will be undefined too.
582 adns_status adns__findrr_anychk(adns_query qu, int serv,
583 const byte *dgram, int dglen, int *cbyte_io,
584 int *type_r, int *class_r, unsigned long *ttl_r,
585 int *rdlen_r, int *rdstart_r,
586 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
588 /* Like adns__findrr_checked, except that the datagram and
589 * owner to compare with can be specified explicitly.
591 * If the caller thinks they know what the owner of the RR ought to
592 * be they can pass in details in eo_*: this is another (or perhaps
593 * the same datagram), and a pointer to where the putative owner
594 * starts in that datagram. In this case *eo_matched_r will be set
595 * to 1 if the datagram matched or 0 if it did not. Either
596 * both eo_dgram and eo_matched_r must both be non-null, or they
597 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
598 * The eo datagram and contained owner domain MUST be valid and
602 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now);
603 /* Updates the `expires' field in the query, so that it doesn't exceed
607 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
611 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
612 void adns__tcp_closenext(adns_state ads);
613 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
615 void adns__autosys(adns_state ads, struct timeval now);
616 /* Make all the system calls we want to if the application wants us to. */
618 void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io,
619 struct timeval *tv_buf);
620 void adns__timeouts(adns_state ads, int act,
621 struct timeval **tv_io, struct timeval *tvbuf,
623 int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]);
624 void adns__fdevents(adns_state ads,
625 const struct pollfd *pollfds, int npollfds,
626 int maxfd, const fd_set *readfds,
627 const fd_set *writefds, const fd_set *exceptfds,
628 struct timeval now, int *r_r);
630 /* Useful static inline functions: */
632 static inline void timevaladd(struct timeval *tv_io, long ms) {
636 tmp.tv_usec += (ms%1000)*1000000;
637 tmp.tv_sec += ms/1000;
638 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
642 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
643 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
644 static inline int ctype_alpha(int c) {
645 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
648 static inline int errno_resources(int e) { return e==ENOMEM || e==ENOBUFS; }
652 #define MEM_ROUND(sz) \
653 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
654 * sizeof(union maxalign) )
656 #define LIST_INIT(list) ((list).head= (list).tail= 0)
657 #define LINK_INIT(link) ((link).next= (link).back= 0)
659 #define LIST_UNLINK_PART(list,node,part) \
661 if ((node)->part back) (node)->part back->part next= (node)->part next; \
662 else (list).head= (node)->part next; \
663 if ((node)->part next) (node)->part next->part back= (node)->part back; \
664 else (list).tail= (node)->part back; \
667 #define LIST_LINK_TAIL_PART(list,node,part) \
669 (node)->part next= 0; \
670 (node)->part back= (list).tail; \
671 if ((list).tail) (list).tail->part next= (node); else (list).head= (node); \
672 (list).tail= (node); \
675 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
676 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
678 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
679 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
680 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
681 #define GET_L(cb,tv) ( (tv)=0, \
682 (tv)|=(GETIL_B((cb))<<24), \
683 (tv)|=(GETIL_B((cb))<<16), \
684 (tv)|=(GETIL_B((cb))<<8), \