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_CLASS_IN 1
56 #define DNS_INADDR_ARPA "in-addr", "arpa"
67 /* Shared data structures */
88 int dglen, nsstart, nscount, arcount;
98 void (*makefinal)(adns_query qu, void *data);
99 /* Change memory management of *data.
100 * Previously, used alloc_interim, now use alloc_final.
103 adns_status (*convstring)(vbuf *vb, const void *data);
104 /* Converts the RR data to a string representation in vbuf.
105 * vbuf will be appended to (it must have been initialised),
106 * and will not be null-terminated by convstring.
109 adns_status (*parse)(const parseinfo *pai, int cbyte, int max, void *store_r);
110 /* Parse one RR, in dgram of length dglen, starting at cbyte and
111 * extending until at most max.
113 * The RR should be stored at *store_r, of length qu->typei->rrsz.
115 * If there is an overrun which might indicate truncation, it should set
116 * *rdstart to -1; otherwise it may set it to anything else positive.
118 * nsstart is the offset of the authority section.
121 int (*diff_needswap)(adns_state ads, const void *datap_a, const void *datap_b);
122 /* Returns !0 if RR a should be strictly after RR b in the sort order,
123 * 0 otherwise. Must not fail.
127 typedef struct allocnode {
128 struct allocnode *next, *back;
142 void (*callback)(adns_query parent, adns_query child);
144 adns_rr_addr ptr_parent_addr;
145 adns_rr_hostaddr *hostaddr;
151 enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
152 adns_query back, next, parent;
153 struct { adns_query head, tail; } children;
154 struct { adns_query back, next; } siblings;
155 struct { allocnode *head, *tail; } allocations;
157 void *final_allocspace;
159 const typeinfo *typei;
164 /* General-purpose messing-about buffer.
165 * Wherever a `big' interface is crossed, this may be corrupted/changed
166 * unless otherwise specified.
170 /* This is allocated when a query is submitted, to avoid being unable
171 * to relate errors to queries if we run out of memory. During
172 * query processing status, rrs is 0. cname is set if
173 * we found a cname (this corresponds to cname_dgram in the query
174 * structure). type is set from the word go. nrrs and rrs
175 * are set together, when we find how many rrs there are.
179 int cname_dglen, cname_begin;
180 /* If non-0, has been allocated using . */
182 int id, flags, udpretries;
184 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
185 struct timeval timeout;
186 time_t expires; /* Earliest expiry time of any record we used. */
192 * state Queue child id nextudpserver sentudp failedtcp
194 * udp NONE null >=0 0 zero zero
195 * udp timew null >=0 any nonzero zero
196 * udp NONE null >=0 any nonzero zero
198 * tcpwait timew null >=0 irrelevant zero any
199 * tcpsent timew null >=0 irrelevant zero any
201 * child childw set >=0 irrelevant irrelevant irrelevant
202 * done output null -1 irrelevant irrelevant irrelevant
204 * +------------------------+
205 * START -----> | udp/NONE |
206 * +------------------------+
208 * too big for UDP / UDP timeout \ \ send via UDP
209 * do this ASAP! / more retries \ \ do this ASAP!
211 * +---------------+ +-----------+
212 * | tcpwait/timew | ____ | udp/timew |
213 * +---------------+ \ +-----------+
215 * TCP conn'd; | | TCP died | | |
216 * send via TCP | | more | UDP timeout | |
217 * do this ASAP! | | servers | no more | |
218 * v | to try | retries | |
219 * +---------------+ | desired | |
220 * | tcpsent/timew | ____ | | |
221 * +---------------+ \| | |
222 * \ \ TCP died | TCP | |
223 * \ \ no more | timeout / |
227 * reply \ _| +------------------+ / reply
228 * \ | done/output FAIL | /
229 * \ +------------------+ /
232 * (..... got reply ....)
234 * need child query/ies / \ no child query
237 * +--------------+ +----------------+
238 * | child/childw | ----------------> | done/output OK |
239 * +--------------+ children done +----------------+
244 adns_initflags iflags;
247 struct { adns_query head, tail; } timew, childw, output;
248 int nextid, udpsocket, tcpsocket;
249 vbuf tcpsend, tcprecv;
250 int nservers, nsortlist, tcpserver;
251 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
252 struct timeval tcptimeout;
253 struct sigaction stdsigpipe;
257 } servers[MAXSERVERS];
259 struct in_addr base, mask;
260 } sortlist[MAXSORTLIST];
265 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
267 /* From general.c: */
269 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
270 int serv, adns_query qu, const char *fmt, va_list al);
272 void adns__debug(adns_state ads, int serv, adns_query qu,
273 const char *fmt, ...) PRINTFFORMAT(4,5);
274 void adns__warn(adns_state ads, int serv, adns_query qu,
275 const char *fmt, ...) PRINTFFORMAT(4,5);
276 void adns__diag(adns_state ads, int serv, adns_query qu,
277 const char *fmt, ...) PRINTFFORMAT(4,5);
279 int adns__vbuf_ensure(vbuf *vb, int want);
280 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
281 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
282 /* 1=>success, 0=>realloc failed */
283 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
284 void adns__vbuf_init(vbuf *vb);
285 void adns__vbuf_free(vbuf *vb);
287 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
288 vbuf *vb, const byte *dgram, int dglen, int cbyte);
289 /* Unpicks a domain in a datagram and returns a string suitable for
290 * printing it as. Never fails - if an error occurs, it will
291 * return some kind of string describing the error.
293 * serv may be -1 and qu may be 0. vb must have been initialised,
294 * and will be left in an arbitrary consistent state.
296 * Returns either vb->buf, or a pointer to a string literal. Do not modify
297 * vb before using the return value.
300 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
301 int (*needswap)(void *context, const void *a, const void *b),
303 /* Does an insertion sort of array which must contain nobjs objects
304 * each sz bytes long. tempbuf must point to a buffer at least
305 * sz bytes long. needswap should return !0 if a>b (strictly, ie
306 * wrong order) 0 if a<=b (ie, order is fine).
309 void adns__sigpipe_protect(adns_state);
310 void adns__sigpipe_unprotect(adns_state);
311 /* If SIGPIPE protection is not disabled, will block all signals except
312 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
313 * Each call to _protect must be followed by a call to _unprotect before
314 * any significant amount of code gets to run.
317 /* From transmit.c: */
319 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
320 const char *owner, int ol,
321 const typeinfo *typei, adns_queryflags flags);
322 /* Assembles a query packet in vb, and returns id at *id_r. */
324 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
325 const byte *qd_dgram, int qd_dglen, int qd_begin,
326 adns_rrtype type, adns_queryflags flags);
327 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
328 * That domain must be correct and untruncated.
331 void adns__query_tcp(adns_query qu, struct timeval now);
332 /* Query must be in state tcpwait/timew; it will be moved to a new state
333 * if possible and no further processing can be done on it for now.
334 * (Resulting state is one of tcpwait/timew (if server not connected),
335 * tcpsent/timew, child/childw or done/output.)
337 * adns__tcp_tryconnect should already have been called - _tcp
338 * will only use an existing connection (if there is one), which it
339 * may break. If the conn list lost then the caller is responsible for any
340 * reestablishment and retry.
343 void adns__query_udp(adns_query qu, struct timeval now);
344 /* Query must be in state udp/NONE; it will be moved to a new state,
345 * and no further processing can be done on it for now.
346 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
347 * tcpsent/timew, child/childw or done/output.)
352 int adns__internal_submit(adns_state ads, adns_query *query_r,
353 const typeinfo *typei, vbuf *qumsg_vb, int id,
354 adns_queryflags flags, struct timeval now,
355 adns_status failstat, const qcontext *ctx);
356 /* Submits a query (for internal use, called during external submits).
358 * The new query is returned in *query_r, or we return adns_s_nomemory.
360 * The query datagram should already have been assembled in qumsg_vb;
361 * the memory for it is _taken over_ by this routine whether it
362 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
364 * If failstat is nonzero then if we are successful in creating the query
365 * it is immediately failed with code failstat (but _submit still succeds).
367 * *ctx is copied byte-for-byte into the query.
370 void *adns__alloc_interim(adns_query qu, size_t sz);
371 /* Allocates some memory, and records which query it came from
372 * and how much there was.
374 * If an error occurs in the query, all its memory is simply freed.
376 * If the query succeeds, one large buffer will be made which is
377 * big enough for all these allocations, and then adns__alloc_final
378 * will get memory from this buffer.
380 * _alloc_interim can fail (and return 0).
381 * The caller must ensure that the query is failed.
383 * adns__alloc_interim_{only,fail}(qu,0) will not return 0,
384 * but it will not necessarily return a distinct pointer each time.
387 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
388 /* Transfers an interim allocation from one query to another, so that
389 * the `to' query will have room for the data when we get to makefinal
390 * and so that the free will happen when the `to' query is freed
391 * rather than the `from' query.
393 * It is legal to call adns__transfer_interim with a null pointer; this
396 * _transfer_interim also ensures that the expiry time of the `to' query
397 * is no later than that of the `from' query, so that child queries'
398 * TTLs get inherited by their parents.
401 void *adns__alloc_mine(adns_query qu, size_t sz);
402 /* Like _interim, but does not record the length for later
403 * copying into the answer. This just ensures that the memory
404 * will be freed when we're done with the query.
407 void *adns__alloc_final(adns_query qu, size_t sz);
408 /* Cannot fail, and cannot return 0.
411 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
412 void adns__makefinal_str(adns_query qu, char **strp);
414 void adns__reset_cnameonly(adns_query qu);
415 /* Resets all of the memory management stuff etc. to
416 * take account of only the CNAME. Used when we find an error somewhere
417 * and want to just report the error (with perhaps CNAME info), and also
418 * when we're halfway through RRs in a datagram and discover that we
419 * need to retry the query.
422 void adns__query_done(adns_query qu);
423 void adns__query_fail(adns_query qu, adns_status stat);
427 void adns__procdgram(adns_state ads, const byte *dgram, int len,
428 int serv, struct timeval now);
432 const typeinfo *adns__findtype(adns_rrtype type);
441 int dglen, max, cbyte, namelen;
445 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
446 int serv, adns_query qu,
447 const byte *dgram, int dglen, int max,
448 int dmbegin, int *dmend_rlater);
449 /* Finds labels in a domain in a datagram.
451 * Call this routine first.
452 * dmend_rlater may be null. ads (and of course fls) may not be.
453 * serv may be -1, qu may be null - they are for error reporting.
456 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
457 /* Then, call this one repeatedly.
459 * It will return adns_s_ok if all is well, and tell you the length
460 * and start of successive labels. labstart_r may be null, but
461 * lablen_r must not be.
463 * After the last label, it will return with *lablen_r zero.
464 * Do not then call it again; instead, just throw away the findlabel_state.
466 * *dmend_rlater will have been set to point to the next part of
467 * the datagram after the label (or after the uncompressed part,
468 * if compression was used). *namelen_rlater will have been set
469 * to the length of the domain name (total length of labels plus
470 * 1 for each intervening dot).
472 * If the datagram appears to be truncated, *lablen_r will be -1.
473 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
474 * Do not call _next again.
476 * There may also be errors, in which case *dmend_rlater,
477 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
478 * Do not then call findlabel_next again.
485 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
486 vbuf *vb, parsedomain_flags flags,
487 const byte *dgram, int dglen, int *cbyte_io, int max);
488 /* vb must already have been initialised; it will be reset if necessary.
489 * If there is truncation, vb->used will be set to 0; otherwise
490 * (if there is no error) vb will be null-terminated.
491 * If there is an error vb and *cbyte_io may be left indeterminate.
493 * serv may be -1 and qu may be 0 - they are used for error reporting only.
496 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
497 adns_query qu, vbuf *vb, parsedomain_flags flags,
499 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
500 * for continuing an existing domain or some such of some kind. Also, unlike
501 * _parse_domain, the domain data will be appended to vb, rather than replacing
502 * the existing contents.
505 adns_status adns__findrr(adns_query qu, int serv,
506 const byte *dgram, int dglen, int *cbyte_io,
507 int *type_r, int *class_r, unsigned long *ttl_r,
508 int *rdlen_r, int *rdstart_r,
509 int *ownermatchedquery_r);
510 /* Finds the extent and some of the contents of an RR in a datagram
511 * and does some checks. The datagram is *dgram, length dglen, and
512 * the RR starts at *cbyte_io (which is updated afterwards to point
513 * to the end of the RR).
515 * The type, class, TTL and RRdata length and start are returned iff
516 * the corresponding pointer variables are not null. type_r, class_r
517 * and ttl_r may not be null. The TTL will be capped.
519 * If ownermatchedquery_r != 0 then the owner domain of this
520 * RR will be compared with that in the query (or, if the query
521 * has gone to a CNAME lookup, with the canonical name).
522 * In this case, *ownermatchedquery_r will be set to 0 or 1.
523 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
525 * If there is truncation then *type_r will be set to -1 and
526 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
529 * qu must obviously be non-null.
531 * If an error is returned then *type_r will be undefined too.
534 adns_status adns__findrr_anychk(adns_query qu, int serv,
535 const byte *dgram, int dglen, int *cbyte_io,
536 int *type_r, int *class_r, unsigned long *ttl_r,
537 int *rdlen_r, int *rdstart_r,
538 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
540 /* Like adns__findrr_checked, except that the datagram and
541 * owner to compare with can be specified explicitly.
543 * If the caller thinks they know what the owner of the RR ought to
544 * be they can pass in details in eo_*: this is another (or perhaps
545 * the same datagram), and a pointer to where the putative owner
546 * starts in that datagram. In this case *eo_matched_r will be set
547 * to 1 if the datagram matched or 0 if it did not. Either
548 * both eo_dgram and eo_matched_r must both be non-null, or they
549 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
550 * The eo datagram and contained owner domain MUST be valid and
554 void adns__update_expires(adns_query qu, unsigned long ttl, struct timeval now);
555 /* Updates the `expires' field in the query, so that it doesn't exceed
559 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
563 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
564 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
566 void adns__autosys(adns_state ads, struct timeval now);
567 /* Make all the system calls we want to if the application wants us to. */
569 /* Useful static inline functions: */
571 static inline void timevaladd(struct timeval *tv_io, long ms) {
575 tmp.tv_usec += (ms%1000)*1000000;
576 tmp.tv_sec += ms/1000;
577 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
581 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
582 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
583 static inline int ctype_alpha(int c) {
584 return (c >= 'a' && c <= 'z') || (c >= 'A' || c <= 'Z');
589 #define MEM_ROUND(sz) \
590 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
591 * sizeof(union maxalign) )
593 #define LIST_INIT(list) ((list).head= (list).tail= 0)
595 #define LIST_UNLINK_PART(list,node,part) \
597 if ((node)->part back) (node)->part back->part next= (node)->part next; \
598 else (list).head= (node)->part next; \
599 if ((node)->part next) (node)->part next->part back= (node)->part back; \
600 else (list).tail= (node)->part back; \
603 #define LIST_LINK_TAIL_PART(list,node,part) \
605 (node)->part next= 0; \
606 (node)->part back= (list).tail; \
607 if ((list).tail) (list).tail->part next= (node); else (list).head= (node); \
608 (list).tail= (node); \
611 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
612 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
614 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
615 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
616 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
617 #define GET_L(cb,tv) ( (tv)=0, \
618 (tv)|=(GETIL_B((cb))<<24), \
619 (tv)|=(GETIL_B((cb))<<16), \
620 (tv)|=(GETIL_B((cb))<<8), \