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, 1998 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
28 #define PRINTFFORMAT(a,b) __attribute__((format(printf,a,b)))
29 typedef unsigned char byte;
39 /* Configuration and constants */
42 #define UDPMAXRETRIES /*15*/5
43 #define UDPRETRYMS 2000
45 #define LOCALRESOURCEMS 20
48 #define DNS_MAXUDP 512
49 #define DNS_MAXDOMAIN 255
50 #define DNS_HDRSIZE 12
51 #define DNS_CLASS_IN 1
62 /* Shared data structures */
89 void (*makefinal)(adns_query qu, void *data);
90 /* Change memory management of *data.
91 * Previously, used alloc_interim, now use alloc_final.
94 adns_status (*convstring)(vbuf *vb, const void *data);
95 /* Converts the RR data to a string representation in vbuf.
96 * vbuf will be appended to (it must have been initialised),
97 * and will not be null-terminated by convstring.
100 adns_status (*parse)(adns_query qu, int serv,
101 const byte *dgram, int dglen, int cbyte, int max,
102 int nsstart, int *arstart_io, void *store_r);
103 /* Parse one RR, in dgram of length dglen, starting at cbyte and
104 * extending until at most max.
106 * The RR should be stored at *store_r, of length qu->typei->rrsz.
108 * If there is an overrun which might indicate truncation, it should set
109 * *rdstart to -1; otherwise it may set it to anything else positive.
111 * nsstart is the offset of the authority section; *arstart_io is
112 * -1 or the offset of the additional section; if it is -1 then
113 * parse may set it to the correct offset.
116 int (*diff_needswap)(const void *datap_a, const void *datap_b);
117 /* Returns !0 if RR a should be strictly after RR b in the sort order,
118 * 0 otherwise. Must not fail.
122 typedef struct allocnode {
123 struct allocnode *next;
137 enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
138 adns_query back, next, parent;
139 struct { adns_query head, tail; } children;
140 struct { adns_query back, next; } siblings;
141 struct allocnode *allocations;
143 void *final_allocspace;
145 const typeinfo *typei;
150 /* General-purpose messing-about buffer.
151 * Wherever a `big' interface is crossed, this may be corrupted/changed
152 * unless otherwise specified.
156 /* This is allocated when a query is submitted, to avoid being unable
157 * to relate errors to queries if we run out of memory. During
158 * query processing status, rrs is 0. cname is set if
159 * we found a cname (this corresponds to cname_dgram in the query
160 * structure). type is set from the word go. nrrs and rrs
161 * are set together, when we find how many rrs there are.
165 int cname_dglen, cname_begin;
166 /* If non-0, has been allocated using . */
168 int id, flags, udpretries;
170 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
171 struct timeval timeout;
176 * state Queue child id nextudpserver sentudp failedtcp
178 * udp NONE null >=0 0 zero zero
179 * udp timew null >=0 any nonzero zero
180 * udp NONE null >=0 any nonzero zero
182 * tcpwait timew null >=0 irrelevant zero any
183 * tcpsent timew null >=0 irrelevant zero any
185 * child childw set >=0 irrelevant irrelevant irrelevant
186 * done output null -1 irrelevant irrelevant irrelevant
188 * +------------------------+
189 * START -----> | udp/NONE |
190 * +------------------------+
192 * too big for UDP / UDP timeout \ \ send via UDP
193 * do this ASAP! / more retries \ \ do this ASAP!
195 * +---------------+ +-----------+
196 * | tcpwait/timew | ____ | udp/timew |
197 * +---------------+ \ +-----------+
199 * TCP conn'd; | | TCP died | | |
200 * send via TCP | | more | UDP timeout | |
201 * do this ASAP! | | servers | no more | |
202 * v | to try | retries | |
203 * +---------------+ | desired | |
204 * | tcpsent/timew | ____ | | |
205 * +---------------+ \| | |
206 * \ \ TCP died | TCP | |
207 * \ \ no more | timeout / |
211 * reply \ _| +------------------+ / reply
212 * \ | done/output FAIL | /
213 * \ +------------------+ /
216 * (..... got reply ....)
218 * need child query/ies / \ no child query
221 * +--------------+ +----------------+
222 * | child/childw | ----------------> | done/output OK |
223 * +--------------+ children done +----------------+
228 adns_initflags iflags;
230 struct { adns_query head, tail; } timew, childw, output;
231 int nextid, udpsocket, tcpsocket;
232 vbuf tcpsend, tcprecv;
233 int nservers, tcpserver;
234 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
235 struct timeval tcptimeout;
238 } servers[MAXSERVERS];
243 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
245 /* From general.c: */
247 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
248 int serv, adns_query qu, const char *fmt, va_list al);
250 void adns__debug(adns_state ads, int serv, adns_query qu,
251 const char *fmt, ...) PRINTFFORMAT(4,5);
252 void adns__warn(adns_state ads, int serv, adns_query qu,
253 const char *fmt, ...) PRINTFFORMAT(4,5);
254 void adns__diag(adns_state ads, int serv, adns_query qu,
255 const char *fmt, ...) PRINTFFORMAT(4,5);
257 int adns__vbuf_ensure(vbuf *vb, int want);
258 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
259 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
260 /* 1=>success, 0=>realloc failed */
261 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
262 void adns__vbuf_init(vbuf *vb);
263 void adns__vbuf_free(vbuf *vb);
265 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
266 vbuf *vb, const byte *dgram, int dglen, int cbyte);
267 /* Unpicks a domain in a datagram and returns a string suitable for
268 * printing it as. Never fails - if an error occurs, it will
269 * return some kind of string describing the error.
271 * serv may be -1 and qu may be 0. vb must have been initialised,
272 * and will be left in an arbitrary consistent state.
274 * Returns either vb->buf, or a pointer to a string literal. Do not modify
275 * vb before using the return value.
278 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
279 int (*needswap)(const void *a, const void *b));
280 /* Does an insertion sort of array which must contain nobjs objects
281 * each sz bytes long. tempbuf must point to a buffer at least
282 * sz bytes long. needswap should return !0 if a>b (strictly, ie
283 * wrong order) 0 if a<=b (ie, order is fine).
286 /* From transmit.c: */
288 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
289 const char *owner, int ol,
290 const typeinfo *typei, adns_queryflags flags);
291 /* Assembles a query packet in vb, and returns id at *id_r. */
293 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
294 const byte *qd_dgram, int qd_dglen, int qd_begin,
295 adns_rrtype type, adns_queryflags flags);
296 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
297 * That domain must be correct and untruncated.
300 void adns__query_tcp(adns_query qu, struct timeval now);
301 /* Query must be in state tcpwait/timew; it will be moved to a new state
302 * if possible and no further processing can be done on it for now.
303 * (Resulting state is one of tcpwait/timew (if server not connected),
304 * tcpsent/timew, child/childw or done/output.)
306 * adns__tcp_tryconnect should already have been called - _tcp
307 * will only use an existing connection (if there is one), which it
308 * may break. If the conn list lost then the caller is responsible for any
309 * reestablishment and retry.
312 void adns__query_udp(adns_query qu, struct timeval now);
313 /* Query must be in state udp/NONE; it will be moved to a new state,
314 * and no further processing can be done on it for now.
315 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
316 * tcpsent/timew, child/childw or done/output.)
321 int adns__internal_submit(adns_state ads, adns_query *query_r,
322 const typeinfo *typei, vbuf *qumsg_vb, int id,
323 adns_queryflags flags, struct timeval now,
324 adns_status failstat, const qcontext *ctx);
325 /* Submits a query (for internal use, called during external submits).
327 * The new query is returned in *query_r, or we return adns_s_nomemory.
329 * The query datagram should already have been assembled in qumsg_vb;
330 * the memory for it is _taken over_ by this routine whether it
331 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
333 * If failstat is nonzero then if we are successful in creating the query
334 * it is immediately failed with code failstat (but _submit still succeds).
336 * ctx is copied byte-for-byte into the query.
339 void *adns__alloc_interim(adns_query qu, size_t sz);
340 /* Allocates some memory, and records which query it came from
341 * and how much there was.
343 * If an error occurs in the query, all its memory is simply freed.
345 * If the query succeeds, one large buffer will be made which is
346 * big enough for all these allocations, and then adns__alloc_final
347 * will get memory from this buffer.
349 * _alloc_interim can fail (and return 0).
350 * The caller must ensure that the query is failed.
352 * adns__alloc_interim_{only,fail}(qu,0) will not return 0,
353 * but it will not necessarily return a distinct pointer each time.
356 void *adns__alloc_mine(adns_query qu, size_t sz);
357 /* Like _interim, but does not record the length for later
358 * copying into the answer. This just ensures that the memory
359 * will be freed when we're done with the query.
362 void *adns__alloc_final(adns_query qu, size_t sz);
363 /* Cannot fail, and cannot return 0.
366 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
367 void adns__makefinal_str(adns_query qu, char **strp);
369 void adns__reset_cnameonly(adns_query qu);
370 /* Resets all of the memory management stuff etc. to
371 * take account of only the CNAME. Used when we find an error somewhere
372 * and want to just report the error (with perhaps CNAME info), and also
373 * when we're halfway through RRs in a datagram and discover that we
374 * need to retry the query.
377 void adns__query_done(adns_query qu);
378 void adns__query_fail(adns_query qu, adns_status stat);
382 void adns__procdgram(adns_state ads, const byte *dgram, int len,
383 int serv, struct timeval now);
387 const typeinfo *adns__findtype(adns_rrtype type);
396 int dglen, max, cbyte, namelen;
400 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
401 int serv, adns_query qu,
402 const byte *dgram, int dglen, int max,
403 int dmbegin, int *dmend_rlater);
404 /* Finds labels in a domain in a datagram.
406 * Call this routine first.
407 * dmend_rlater may be null. ads (and of course fls) may not be.
408 * serv may be -1, qu may be null - they are for error reporting.
411 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
412 /* Then, call this one repeatedly.
414 * It will return adns_s_ok if all is well, and tell you the length
415 * and start of successive labels. labstart_r may be null, but
416 * lablen_r must not be.
418 * After the last label, it will return with *lablen_r zero.
419 * Do not then call it again; instead, just throw away the findlabel_state.
421 * *dmend_rlater will have been set to point to the next part of
422 * the datagram after the label (or after the uncompressed part,
423 * if compression was used). *namelen_rlater will have been set
424 * to the length of the domain name (total length of labels plus
425 * 1 for each intervening dot).
427 * If the datagram appears to be truncated, *lablen_r will be -1.
428 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
429 * Do not call _next again.
431 * There may also be errors, in which case *dmend_rlater,
432 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
433 * Do not then call findlabel_next again.
440 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
441 vbuf *vb, parsedomain_flags flags,
442 const byte *dgram, int dglen, int *cbyte_io, int max);
443 /* vb must already have been initialised; it will be reset if necessary.
444 * If there is truncation, vb->used will be set to 0; otherwise
445 * (if there is no error) vb will be null-terminated.
446 * If there is an error vb and *cbyte_io may be left indeterminate.
448 * serv may be -1 and qu may be 0 - they are used for error reporting only.
451 adns_status adns__findrr(adns_query qu, int serv,
452 const byte *dgram, int dglen, int *cbyte_io,
453 int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
454 int *ownermatchedquery_r);
455 /* Finds the extent and some of the contents of an RR in a datagram
456 * and does some checks. The datagram is *dgram, length dglen, and
457 * the RR starts at *cbyte_io (which is updated afterwards to point
458 * to the end of the RR).
460 * The type, class and RRdata length and start are returned iff
461 * the corresponding pointer variables are not null. type_r and
462 * class_r may not be null.
464 * If ownermatchedquery_r != 0 then the owner domain of this
465 * RR will be compared with that in the query (or, if the query
466 * has gone to a CNAME lookup, with the canonical name).
467 * In this case, *ownermatchedquery_r will be set to 0 or 1.
468 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
470 * If there is truncation then *type_r will be set to -1 and
471 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
474 * qu must obviously be non-null.
476 * If an error is returned then *type_r will be undefined too.
479 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
483 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
484 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
486 void adns__autosys(adns_state ads, struct timeval now);
487 /* Make all the system calls we want to if the application wants us to. */
489 /* Useful static inline functions: */
491 static inline void timevaladd(struct timeval *tv_io, long ms) {
495 tmp.tv_usec += (ms%1000)*1000000;
496 tmp.tv_sec += ms/1000;
497 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
501 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
502 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
503 static inline int ctype_alpha(int c) {
504 return (c >= 'a' && c <= 'z') || (c >= 'A' || c <= 'Z');
509 #define MEM_ROUND(sz) \
510 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
511 * sizeof(union maxalign) )
513 #define LIST_INIT(list) ((list).head= (list).tail= 0)
515 #define LIST_UNLINK_PART(list,node,part) \
517 if ((node)->back) (node)->back->part next= (node)->part next; \
518 else (list).head= (node)->part next; \
519 if ((node)->next) (node)->next->part back= (node)->part back; \
520 else (list).tail= (node)->part back; \
523 #define LIST_LINK_TAIL_PART(list,node,part) \
525 (node)->part next= 0; \
526 (node)->part back= (list).tail; \
527 if ((list).tail) (list).tail->part next= (node); else (list).part head= (node); \
528 (list).tail= (node); \
531 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
532 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
534 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
535 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
536 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))