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;
40 /* Configuration and constants */
43 #define MAXSORTLIST 15
44 #define UDPMAXRETRIES 15
45 #define UDPRETRYMS 2000
47 #define LOCALRESOURCEMS 20
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"
68 /* Shared data structures */
89 int dglen, nsstart, nscount, arcount;
99 void (*makefinal)(adns_query qu, void *data);
100 /* Change memory management of *data.
101 * Previously, used alloc_interim, now use alloc_final.
104 adns_status (*convstring)(vbuf *vb, const void *data);
105 /* Converts the RR data to a string representation in vbuf.
106 * vbuf will be appended to (it must have been initialised),
107 * and will not be null-terminated by convstring.
110 adns_status (*parse)(const parseinfo *pai, int cbyte, int max, void *store_r);
111 /* Parse one RR, in dgram of length dglen, starting at cbyte and
112 * extending until at most max.
114 * The RR should be stored at *store_r, of length qu->typei->rrsz.
116 * If there is an overrun which might indicate truncation, it should set
117 * *rdstart to -1; otherwise it may set it to anything else positive.
119 * nsstart is the offset of the authority section.
122 int (*diff_needswap)(adns_state ads, const void *datap_a, const void *datap_b);
123 /* Returns !0 if RR a should be strictly after RR b in the sort order,
124 * 0 otherwise. Must not fail.
128 typedef struct allocnode {
129 struct allocnode *next, *back;
143 void (*callback)(adns_query parent, adns_query child);
145 adns_rr_addr ptr_parent_addr;
146 adns_rr_hostaddr *hostaddr;
152 enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
153 adns_query back, next, parent;
154 struct { adns_query head, tail; } children;
155 struct { adns_query back, next; } siblings;
156 struct { allocnode *head, *tail; } allocations;
158 void *final_allocspace;
160 const typeinfo *typei;
165 /* General-purpose messing-about buffer.
166 * Wherever a `big' interface is crossed, this may be corrupted/changed
167 * unless otherwise specified.
171 /* This is allocated when a query is submitted, to avoid being unable
172 * to relate errors to queries if we run out of memory. During
173 * query processing status, rrs is 0. cname is set if
174 * we found a cname (this corresponds to cname_dgram in the query
175 * structure). type is set from the word go. nrrs and rrs
176 * are set together, when we find how many rrs there are.
177 * owner is set during querying unless we're doing searchlist,
178 * in which case it is set only when we find an answer.
182 int cname_dglen, cname_begin;
183 /* If non-0, has been allocated using . */
186 int search_origlen, search_pos, search_doneabs;
187 /* Used by the searching algorithm. The query domain in textual form
188 * is copied into the vbuf, and _origlen set to its length. Then
189 * we walk the searchlist, if we want to. _pos says where we are
190 * (next entry to try), and _doneabs says whether we've done the
191 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
192 * but not done yet). If flags doesn't have adns_qf_search then
193 * the vbuf is initialised but empty and everything else is zero.
196 int id, flags, udpretries;
198 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
199 struct timeval timeout;
200 time_t expires; /* Earliest expiry time of any record we used. */
206 * state Queue child id nextudpserver sentudp failedtcp
208 * udp NONE null >=0 0 zero zero
209 * udp timew null >=0 any nonzero zero
210 * udp NONE null >=0 any nonzero zero
212 * tcpwait timew null >=0 irrelevant zero any
213 * tcpsent timew null >=0 irrelevant zero any
215 * child childw set >=0 irrelevant irrelevant irrelevant
216 * child NONE null >=0 irrelevant irrelevant irrelevant
217 * done output null -1 irrelevant irrelevant irrelevant
219 * Queries are only not on a queue when they are actually being processed.
221 * +------------------------+
222 * START -----> | udp/NONE |
223 * +------------------------+
225 * too big for UDP / UDP timeout \ \ send via UDP
226 * do this ASAP! / more retries \ \ do this ASAP!
228 * +---------------+ +-----------+
229 * | tcpwait/timew | ____ | udp/timew |
230 * +---------------+ \ +-----------+
232 * TCP conn'd; | | TCP died | | |
233 * send via TCP | | more | UDP timeout | |
234 * do this ASAP! | | servers | no more | |
235 * v | to try | retries | |
236 * +---------------+ | desired | |
237 * | tcpsent/timew | ____ | | |
238 * +---------------+ \| | |
239 * \ \ TCP died | TCP | |
240 * \ \ no more | timeout / |
244 * reply \ _| +------------------+ / reply
245 * \ | done/output FAIL | /
246 * \ +------------------+ /
249 * (..... got reply ....)
251 * need child query/ies / \ no child query
254 * +--------------+ +----------------+
255 * | child/childw | ----------------> | done/output OK |
256 * +--------------+ children done +----------------+
261 adns_initflags iflags;
264 struct { adns_query head, tail; } timew, childw, output;
265 int nextid, udpsocket, tcpsocket;
266 vbuf tcpsend, tcprecv;
267 int nservers, nsortlist, nsearchlist, searchndots, tcpserver;
268 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
269 struct timeval tcptimeout;
270 struct sigaction stdsigpipe;
274 } servers[MAXSERVERS];
276 struct in_addr base, mask;
277 } sortlist[MAXSORTLIST];
283 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
285 /* From general.c: */
287 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
288 int serv, adns_query qu, const char *fmt, va_list al);
290 void adns__debug(adns_state ads, int serv, adns_query qu,
291 const char *fmt, ...) PRINTFFORMAT(4,5);
292 void adns__warn(adns_state ads, int serv, adns_query qu,
293 const char *fmt, ...) PRINTFFORMAT(4,5);
294 void adns__diag(adns_state ads, int serv, adns_query qu,
295 const char *fmt, ...) PRINTFFORMAT(4,5);
297 int adns__vbuf_ensure(vbuf *vb, int want);
298 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
299 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
300 /* 1=>success, 0=>realloc failed */
301 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
302 void adns__vbuf_init(vbuf *vb);
303 void adns__vbuf_free(vbuf *vb);
305 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
306 vbuf *vb, const byte *dgram, int dglen, int cbyte);
307 /* Unpicks a domain in a datagram and returns a string suitable for
308 * printing it as. Never fails - if an error occurs, it will
309 * return some kind of string describing the error.
311 * serv may be -1 and qu may be 0. vb must have been initialised,
312 * and will be left in an arbitrary consistent state.
314 * Returns either vb->buf, or a pointer to a string literal. Do not modify
315 * vb before using the return value.
318 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
319 int (*needswap)(void *context, const void *a, const void *b),
321 /* Does an insertion sort of array which must contain nobjs objects
322 * each sz bytes long. tempbuf must point to a buffer at least
323 * sz bytes long. needswap should return !0 if a>b (strictly, ie
324 * wrong order) 0 if a<=b (ie, order is fine).
327 void adns__sigpipe_protect(adns_state);
328 void adns__sigpipe_unprotect(adns_state);
329 /* If SIGPIPE protection is not disabled, will block all signals except
330 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
331 * Each call to _protect must be followed by a call to _unprotect before
332 * any significant amount of code gets to run.
335 /* From transmit.c: */
337 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
338 const char *owner, int ol,
339 const typeinfo *typei, adns_queryflags flags);
340 /* Assembles a query packet in vb. A new id is allocated and returned.
343 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
344 const byte *qd_dgram, int qd_dglen, int qd_begin,
345 adns_rrtype type, adns_queryflags flags);
346 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
347 * That domain must be correct and untruncated.
350 void adns__query_tcp(adns_query qu, struct timeval now);
351 /* Query must be in state tcpwait/timew; it will be moved to a new state
352 * if possible and no further processing can be done on it for now.
353 * (Resulting state is one of tcpwait/timew (if server not connected),
354 * tcpsent/timew, child/childw or done/output.)
356 * adns__tcp_tryconnect should already have been called - _tcp
357 * will only use an existing connection (if there is one), which it
358 * may break. If the conn list lost then the caller is responsible for any
359 * reestablishment and retry.
362 void adns__query_udp(adns_query qu, struct timeval now);
363 /* Query must be in state udp/NONE; it will be moved to a new state,
364 * and no further processing can be done on it for now.
365 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
366 * tcpsent/timew, child/childw or done/output.)
371 adns_status adns__internal_submit(adns_state ads, adns_query *query_r,
372 const typeinfo *typei, vbuf *qumsg_vb, int id,
373 adns_queryflags flags, struct timeval now,
374 const qcontext *ctx);
375 /* Submits a query (for internal use, called during external submits).
377 * The new query is returned in *query_r, or we return adns_s_nomemory.
379 * The query datagram should already have been assembled in qumsg_vb;
380 * the memory for it is _taken over_ by this routine whether it
381 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
383 * *ctx is copied byte-for-byte into the query.
385 * When the child query is done, ctx->callback will be called. The
386 * child will already have been taken off both the global list of
387 * queries in ads and the list of children in the parent. The child
388 * will be freed when the callback returns. The parent will have been
389 * taken off the global childw queue iff this is the last child for
390 * that parent. If there is no error detected in the callback, then
391 * it should call adns__query_done if and only if there are no more
392 * children (by checking parent->children.head). If an error is
393 * detected in the callback it should call adns__query_fail and any
394 * remaining children will automatically be cancelled.
397 void adns__search_next(adns_state ads, adns_query qu, struct timeval now);
398 /* Walks down the searchlist for a query with adns_qf_search.
399 * The query should have just had a negative response, or not had
400 * any queries sent yet, and should not be on any queue.
401 * The query_dgram if any will be freed and forgotten and a new
402 * one constructed from the search_* members of the query.
404 * Cannot fail (in case of error, calls adns__query_fail).
407 void *adns__alloc_interim(adns_query qu, size_t sz);
408 /* Allocates some memory, and records which query it came from
409 * and how much there was.
411 * If an error occurs in the query, all its memory is simply freed.
413 * If the query succeeds, one large buffer will be made which is
414 * big enough for all these allocations, and then adns__alloc_final
415 * will get memory from this buffer.
417 * _alloc_interim can fail (and return 0).
418 * The caller must ensure that the query is failed.
420 * adns__alloc_interim_{only,fail}(qu,0) will not return 0,
421 * but it will not necessarily return a distinct pointer each time.
424 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
425 /* Transfers an interim allocation from one query to another, so that
426 * the `to' query will have room for the data when we get to makefinal
427 * and so that the free will happen when the `to' query is freed
428 * rather than the `from' query.
430 * It is legal to call adns__transfer_interim with a null pointer; this
433 * _transfer_interim also ensures that the expiry time of the `to' query
434 * is no later than that of the `from' query, so that child queries'
435 * TTLs get inherited by their parents.
438 void *adns__alloc_mine(adns_query qu, size_t sz);
439 /* Like _interim, but does not record the length for later
440 * copying into the answer. This just ensures that the memory
441 * will be freed when we're done with the query.
444 void *adns__alloc_final(adns_query qu, size_t sz);
445 /* Cannot fail, and cannot return 0.
448 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
449 void adns__makefinal_str(adns_query qu, char **strp);
451 void adns__reset_cnameonly(adns_query qu);
452 /* Resets all of the memory management stuff etc. to
453 * take account of only the CNAME. Used when we find an error somewhere
454 * and want to just report the error (with perhaps CNAME info), and also
455 * when we're halfway through RRs in a datagram and discover that we
456 * need to retry the query.
459 void adns__query_done(adns_query qu);
460 void adns__query_fail(adns_query qu, adns_status stat);
464 void adns__procdgram(adns_state ads, const byte *dgram, int len,
465 int serv, struct timeval now);
469 const typeinfo *adns__findtype(adns_rrtype type);
478 int dglen, max, cbyte, namelen;
482 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
483 int serv, adns_query qu,
484 const byte *dgram, int dglen, int max,
485 int dmbegin, int *dmend_rlater);
486 /* Finds labels in a domain in a datagram.
488 * Call this routine first.
489 * dmend_rlater may be null. ads (and of course fls) may not be.
490 * serv may be -1, qu may be null - they are for error reporting.
493 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
494 /* Then, call this one repeatedly.
496 * It will return adns_s_ok if all is well, and tell you the length
497 * and start of successive labels. labstart_r may be null, but
498 * lablen_r must not be.
500 * After the last label, it will return with *lablen_r zero.
501 * Do not then call it again; instead, just throw away the findlabel_state.
503 * *dmend_rlater will have been set to point to the next part of
504 * the datagram after the label (or after the uncompressed part,
505 * if compression was used). *namelen_rlater will have been set
506 * to the length of the domain name (total length of labels plus
507 * 1 for each intervening dot).
509 * If the datagram appears to be truncated, *lablen_r will be -1.
510 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
511 * Do not call _next again.
513 * There may also be errors, in which case *dmend_rlater,
514 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
515 * Do not then call findlabel_next again.
522 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
523 vbuf *vb, parsedomain_flags flags,
524 const byte *dgram, int dglen, int *cbyte_io, int max);
525 /* vb must already have been initialised; it will be reset if necessary.
526 * If there is truncation, vb->used will be set to 0; otherwise
527 * (if there is no error) vb will be null-terminated.
528 * If there is an error vb and *cbyte_io may be left indeterminate.
530 * serv may be -1 and qu may be 0 - they are used for error reporting only.
533 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
534 adns_query qu, vbuf *vb, parsedomain_flags flags,
536 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
537 * for continuing an existing domain or some such of some kind. Also, unlike
538 * _parse_domain, the domain data will be appended to vb, rather than replacing
539 * the existing contents.
542 adns_status adns__findrr(adns_query qu, int serv,
543 const byte *dgram, int dglen, int *cbyte_io,
544 int *type_r, int *class_r, unsigned long *ttl_r,
545 int *rdlen_r, int *rdstart_r,
546 int *ownermatchedquery_r);
547 /* Finds the extent and some of the contents of an RR in a datagram
548 * and does some checks. The datagram is *dgram, length dglen, and
549 * the RR starts at *cbyte_io (which is updated afterwards to point
550 * to the end of the RR).
552 * The type, class, TTL and RRdata length and start are returned iff
553 * the corresponding pointer variables are not null. type_r, class_r
554 * and ttl_r may not be null. The TTL will be capped.
556 * If ownermatchedquery_r != 0 then the owner domain of this
557 * RR will be compared with that in the query (or, if the query
558 * has gone to a CNAME lookup, with the canonical name).
559 * In this case, *ownermatchedquery_r will be set to 0 or 1.
560 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
562 * If there is truncation then *type_r will be set to -1 and
563 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
566 * qu must obviously be non-null.
568 * If an error is returned then *type_r will be undefined too.
571 adns_status adns__findrr_anychk(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 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
577 /* Like adns__findrr_checked, except that the datagram and
578 * owner to compare with can be specified explicitly.
580 * If the caller thinks they know what the owner of the RR ought to
581 * be they can pass in details in eo_*: this is another (or perhaps
582 * the same datagram), and a pointer to where the putative owner
583 * starts in that datagram. In this case *eo_matched_r will be set
584 * to 1 if the datagram matched or 0 if it did not. Either
585 * both eo_dgram and eo_matched_r must both be non-null, or they
586 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
587 * The eo datagram and contained owner domain MUST be valid and
591 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now);
592 /* Updates the `expires' field in the query, so that it doesn't exceed
596 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
600 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
601 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
603 void adns__autosys(adns_state ads, struct timeval now);
604 /* Make all the system calls we want to if the application wants us to. */
606 /* Useful static inline functions: */
608 static inline void timevaladd(struct timeval *tv_io, long ms) {
612 tmp.tv_usec += (ms%1000)*1000000;
613 tmp.tv_sec += ms/1000;
614 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
618 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
619 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
620 static inline int ctype_alpha(int c) {
621 return (c >= 'a' && c <= 'z') || (c >= 'A' || c <= 'Z');
626 #define MEM_ROUND(sz) \
627 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
628 * sizeof(union maxalign) )
630 #define LIST_INIT(list) ((list).head= (list).tail= 0)
631 #define LINK_INIT(link) ((link).next= (link).back= 0)
633 #define LIST_UNLINK_PART(list,node,part) \
635 if ((node)->part back) (node)->part back->part next= (node)->part next; \
636 else (list).head= (node)->part next; \
637 if ((node)->part next) (node)->part next->part back= (node)->part back; \
638 else (list).tail= (node)->part back; \
641 #define LIST_LINK_TAIL_PART(list,node,part) \
643 (node)->part next= 0; \
644 (node)->part back= (list).tail; \
645 if ((list).tail) (list).tail->part next= (node); else (list).head= (node); \
646 (list).tail= (node); \
649 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
650 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
652 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
653 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
654 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
655 #define GET_L(cb,tv) ( (tv)=0, \
656 (tv)|=(GETIL_B((cb))<<24), \
657 (tv)|=(GETIL_B((cb))<<16), \
658 (tv)|=(GETIL_B((cb))<<8), \