sortlist; init supplying text of config file; env vars with config
[adns] / src / internal.h
1 /*
2 * internal.h
3 * - declarations of private objects with external linkage (adns__*)
4 * - definitons of internal macros
5 * - comments regarding library data structures
6 */
7 /*
8 * This file is part of adns, which is Copyright (C) 1997, 1998 Ian Jackson
9 *
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)
13 * any later version.
14 *
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.
19 *
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.
23 */
24
25 #ifndef ADNS_INTERNAL_H_INCLUDED
26 #define ADNS_INTERNAL_H_INCLUDED
27
28 #define PRINTFFORMAT(a,b) __attribute__((format(printf,a,b)))
29 typedef unsigned char byte;
30
31 #include <stdarg.h>
32 #include <assert.h>
33 #include <unistd.h>
34
35 #include <sys/time.h>
36
37 #include "adns.h"
38
39 /* Configuration and constants */
40
41 #define MAXSERVERS 5
42 #define MAXSORTLIST 15
43 #define UDPMAXRETRIES /*15 fixme*/5
44 #define UDPRETRYMS 2000
45 #define TCPMS 30000
46 #define LOCALRESOURCEMS 20
47
48 #define DNS_PORT 53
49 #define DNS_MAXUDP 512
50 #define DNS_MAXDOMAIN 255
51 #define DNS_HDRSIZE 12
52 #define DNS_CLASS_IN 1
53
54 #define DNS_INADDR_ARPA "in-addr", "arpa"
55
56 typedef enum {
57 rcode_noerror,
58 rcode_formaterror,
59 rcode_servfail,
60 rcode_nxdomain,
61 rcode_notimp,
62 rcode_refused
63 } dns_rcode;
64
65 /* Shared data structures */
66
67 typedef union {
68 adns_status status;
69 char *cp;
70 adns_rrtype type;
71 int i;
72 struct in_addr ia;
73 unsigned long ul;
74 } rr_align;
75
76 typedef struct {
77 int used, avail;
78 byte *buf;
79 } vbuf;
80
81 typedef struct {
82 adns_state ads;
83 adns_query qu;
84 int serv;
85 const byte *dgram;
86 int dglen, nsstart, nscount, arcount;
87 struct timeval now;
88 } parseinfo;
89
90 typedef struct {
91 adns_rrtype type;
92 const char *rrtname;
93 const char *fmtname;
94 int rrsz;
95
96 void (*makefinal)(adns_query qu, void *data);
97 /* Change memory management of *data.
98 * Previously, used alloc_interim, now use alloc_final.
99 */
100
101 adns_status (*convstring)(vbuf *vb, const void *data);
102 /* Converts the RR data to a string representation in vbuf.
103 * vbuf will be appended to (it must have been initialised),
104 * and will not be null-terminated by convstring.
105 */
106
107 adns_status (*parse)(const parseinfo *pai, int cbyte, int max, void *store_r);
108 /* Parse one RR, in dgram of length dglen, starting at cbyte and
109 * extending until at most max.
110 *
111 * The RR should be stored at *store_r, of length qu->typei->rrsz.
112 *
113 * If there is an overrun which might indicate truncation, it should set
114 * *rdstart to -1; otherwise it may set it to anything else positive.
115 *
116 * nsstart is the offset of the authority section.
117 */
118
119 int (*diff_needswap)(adns_state ads, const void *datap_a, const void *datap_b);
120 /* Returns !0 if RR a should be strictly after RR b in the sort order,
121 * 0 otherwise. Must not fail.
122 */
123 } typeinfo;
124
125 typedef struct allocnode {
126 struct allocnode *next, *back;
127 } allocnode;
128
129 union maxalign {
130 byte d[1];
131 struct in_addr ia;
132 long l;
133 void *p;
134 void (*fp)(void);
135 union maxalign *up;
136 } data;
137
138 typedef struct {
139 void *ext;
140 void (*callback)(adns_query parent, adns_query child);
141 union {
142 adns_rr_addr ptr_parent_addr;
143 adns_rr_hostaddr *hostaddr;
144 } info;
145 } qcontext;
146
147 struct adns__query {
148 adns_state ads;
149 enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
150 adns_query back, next, parent;
151 struct { adns_query head, tail; } children;
152 struct { adns_query back, next; } siblings;
153 struct { allocnode *head, *tail; } allocations;
154 int interim_allocd;
155 void *final_allocspace;
156
157 const typeinfo *typei;
158 byte *query_dgram;
159 int query_dglen;
160
161 vbuf vb;
162 /* General-purpose messing-about buffer.
163 * Wherever a `big' interface is crossed, this may be corrupted/changed
164 * unless otherwise specified.
165 */
166
167 adns_answer *answer;
168 /* This is allocated when a query is submitted, to avoid being unable
169 * to relate errors to queries if we run out of memory. During
170 * query processing status, rrs is 0. cname is set if
171 * we found a cname (this corresponds to cname_dgram in the query
172 * structure). type is set from the word go. nrrs and rrs
173 * are set together, when we find how many rrs there are.
174 */
175
176 byte *cname_dgram;
177 int cname_dglen, cname_begin;
178 /* If non-0, has been allocated using . */
179
180 int id, flags, udpretries;
181 int udpnextserver;
182 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
183 struct timeval timeout;
184
185 qcontext ctx;
186
187 /* Possible states:
188 *
189 * state Queue child id nextudpserver sentudp failedtcp
190 *
191 * udp NONE null >=0 0 zero zero
192 * udp timew null >=0 any nonzero zero
193 * udp NONE null >=0 any nonzero zero
194 *
195 * tcpwait timew null >=0 irrelevant zero any
196 * tcpsent timew null >=0 irrelevant zero any
197 *
198 * child childw set >=0 irrelevant irrelevant irrelevant
199 * done output null -1 irrelevant irrelevant irrelevant
200 *
201 * +------------------------+
202 * START -----> | udp/NONE |
203 * +------------------------+
204 * / |\ \
205 * too big for UDP / UDP timeout \ \ send via UDP
206 * do this ASAP! / more retries \ \ do this ASAP!
207 * |_ desired \ _|
208 * +---------------+ +-----------+
209 * | tcpwait/timew | ____ | udp/timew |
210 * +---------------+ \ +-----------+
211 * | ^ | | |
212 * TCP conn'd; | | TCP died | | |
213 * send via TCP | | more | UDP timeout | |
214 * do this ASAP! | | servers | no more | |
215 * v | to try | retries | |
216 * +---------------+ | desired | |
217 * | tcpsent/timew | ____ | | |
218 * +---------------+ \| | |
219 * \ \ TCP died | TCP | |
220 * \ \ no more | timeout / |
221 * \ \ servers | / |
222 * \ \ to try | / |
223 * got \ \ v |_ / got
224 * reply \ _| +------------------+ / reply
225 * \ | done/output FAIL | /
226 * \ +------------------+ /
227 * \ /
228 * _| |_
229 * (..... got reply ....)
230 * / \
231 * need child query/ies / \ no child query
232 * / \
233 * |_ _|
234 * +--------------+ +----------------+
235 * | child/childw | ----------------> | done/output OK |
236 * +--------------+ children done +----------------+
237 */
238 };
239
240 struct adns__state {
241 adns_initflags iflags;
242 FILE *diagfile;
243 int configerrno;
244 struct { adns_query head, tail; } timew, childw, output;
245 int nextid, udpsocket, tcpsocket;
246 vbuf tcpsend, tcprecv;
247 int nservers, nsortlist, tcpserver;
248 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
249 struct timeval tcptimeout;
250 struct server {
251 struct in_addr addr;
252 } servers[MAXSERVERS];
253 struct sortlist {
254 struct in_addr base, mask;
255 } sortlist[MAXSORTLIST];
256 };
257
258 /* From setup.c: */
259
260 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
261
262 /* From general.c: */
263
264 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
265 int serv, adns_query qu, const char *fmt, va_list al);
266
267 void adns__debug(adns_state ads, int serv, adns_query qu,
268 const char *fmt, ...) PRINTFFORMAT(4,5);
269 void adns__warn(adns_state ads, int serv, adns_query qu,
270 const char *fmt, ...) PRINTFFORMAT(4,5);
271 void adns__diag(adns_state ads, int serv, adns_query qu,
272 const char *fmt, ...) PRINTFFORMAT(4,5);
273
274 int adns__vbuf_ensure(vbuf *vb, int want);
275 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
276 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
277 /* 1=>success, 0=>realloc failed */
278 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
279 void adns__vbuf_init(vbuf *vb);
280 void adns__vbuf_free(vbuf *vb);
281
282 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu,
283 vbuf *vb, const byte *dgram, int dglen, int cbyte);
284 /* Unpicks a domain in a datagram and returns a string suitable for
285 * printing it as. Never fails - if an error occurs, it will
286 * return some kind of string describing the error.
287 *
288 * serv may be -1 and qu may be 0. vb must have been initialised,
289 * and will be left in an arbitrary consistent state.
290 *
291 * Returns either vb->buf, or a pointer to a string literal. Do not modify
292 * vb before using the return value.
293 */
294
295 void adns__isort(void *array, int nobjs, int sz, void *tempbuf,
296 int (*needswap)(void *context, const void *a, const void *b),
297 void *context);
298 /* Does an insertion sort of array which must contain nobjs objects
299 * each sz bytes long. tempbuf must point to a buffer at least
300 * sz bytes long. needswap should return !0 if a>b (strictly, ie
301 * wrong order) 0 if a<=b (ie, order is fine).
302 */
303
304 /* From transmit.c: */
305
306 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
307 const char *owner, int ol,
308 const typeinfo *typei, adns_queryflags flags);
309 /* Assembles a query packet in vb, and returns id at *id_r. */
310
311 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
312 const byte *qd_dgram, int qd_dglen, int qd_begin,
313 adns_rrtype type, adns_queryflags flags);
314 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
315 * That domain must be correct and untruncated.
316 */
317
318 void adns__query_tcp(adns_query qu, struct timeval now);
319 /* Query must be in state tcpwait/timew; it will be moved to a new state
320 * if possible and no further processing can be done on it for now.
321 * (Resulting state is one of tcpwait/timew (if server not connected),
322 * tcpsent/timew, child/childw or done/output.)
323 *
324 * adns__tcp_tryconnect should already have been called - _tcp
325 * will only use an existing connection (if there is one), which it
326 * may break. If the conn list lost then the caller is responsible for any
327 * reestablishment and retry.
328 */
329
330 void adns__query_udp(adns_query qu, struct timeval now);
331 /* Query must be in state udp/NONE; it will be moved to a new state,
332 * and no further processing can be done on it for now.
333 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
334 * tcpsent/timew, child/childw or done/output.)
335 */
336
337 /* From query.c: */
338
339 int adns__internal_submit(adns_state ads, adns_query *query_r,
340 const typeinfo *typei, vbuf *qumsg_vb, int id,
341 adns_queryflags flags, struct timeval now,
342 adns_status failstat, const qcontext *ctx);
343 /* Submits a query (for internal use, called during external submits).
344 *
345 * The new query is returned in *query_r, or we return adns_s_nomemory.
346 *
347 * The query datagram should already have been assembled in qumsg_vb;
348 * the memory for it is _taken over_ by this routine whether it
349 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
350 *
351 * If failstat is nonzero then if we are successful in creating the query
352 * it is immediately failed with code failstat (but _submit still succeds).
353 *
354 * *ctx is copied byte-for-byte into the query.
355 */
356
357 void *adns__alloc_interim(adns_query qu, size_t sz);
358 /* Allocates some memory, and records which query it came from
359 * and how much there was.
360 *
361 * If an error occurs in the query, all its memory is simply freed.
362 *
363 * If the query succeeds, one large buffer will be made which is
364 * big enough for all these allocations, and then adns__alloc_final
365 * will get memory from this buffer.
366 *
367 * _alloc_interim can fail (and return 0).
368 * The caller must ensure that the query is failed.
369 *
370 * adns__alloc_interim_{only,fail}(qu,0) will not return 0,
371 * but it will not necessarily return a distinct pointer each time.
372 */
373
374 void adns__transfer_interim(adns_query from, adns_query to, void *block, size_t sz);
375 /* Transfers an interim allocation from one query to another, so that
376 * the `to' query will have room for the data when we get to makefinal
377 * and so that the free will happen when the `to' query is freed
378 * rather than the `from' query.
379 *
380 * It is legal to call adns__transfer_interim with a null pointer; this
381 * has no effect.
382 */
383
384 void *adns__alloc_mine(adns_query qu, size_t sz);
385 /* Like _interim, but does not record the length for later
386 * copying into the answer. This just ensures that the memory
387 * will be freed when we're done with the query.
388 */
389
390 void *adns__alloc_final(adns_query qu, size_t sz);
391 /* Cannot fail, and cannot return 0.
392 */
393
394 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
395 void adns__makefinal_str(adns_query qu, char **strp);
396
397 void adns__reset_cnameonly(adns_query qu);
398 /* Resets all of the memory management stuff etc. to
399 * take account of only the CNAME. Used when we find an error somewhere
400 * and want to just report the error (with perhaps CNAME info), and also
401 * when we're halfway through RRs in a datagram and discover that we
402 * need to retry the query.
403 */
404
405 void adns__query_done(adns_query qu);
406 void adns__query_fail(adns_query qu, adns_status stat);
407
408 /* From reply.c: */
409
410 void adns__procdgram(adns_state ads, const byte *dgram, int len,
411 int serv, struct timeval now);
412
413 /* From types.c: */
414
415 const typeinfo *adns__findtype(adns_rrtype type);
416
417 /* From parse.c: */
418
419 typedef struct {
420 adns_state ads;
421 adns_query qu;
422 int serv;
423 const byte *dgram;
424 int dglen, max, cbyte, namelen;
425 int *dmend_r;
426 } findlabel_state;
427
428 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
429 int serv, adns_query qu,
430 const byte *dgram, int dglen, int max,
431 int dmbegin, int *dmend_rlater);
432 /* Finds labels in a domain in a datagram.
433 *
434 * Call this routine first.
435 * dmend_rlater may be null. ads (and of course fls) may not be.
436 * serv may be -1, qu may be null - they are for error reporting.
437 */
438
439 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
440 /* Then, call this one repeatedly.
441 *
442 * It will return adns_s_ok if all is well, and tell you the length
443 * and start of successive labels. labstart_r may be null, but
444 * lablen_r must not be.
445 *
446 * After the last label, it will return with *lablen_r zero.
447 * Do not then call it again; instead, just throw away the findlabel_state.
448 *
449 * *dmend_rlater will have been set to point to the next part of
450 * the datagram after the label (or after the uncompressed part,
451 * if compression was used). *namelen_rlater will have been set
452 * to the length of the domain name (total length of labels plus
453 * 1 for each intervening dot).
454 *
455 * If the datagram appears to be truncated, *lablen_r will be -1.
456 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
457 * Do not call _next again.
458 *
459 * There may also be errors, in which case *dmend_rlater,
460 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
461 * Do not then call findlabel_next again.
462 */
463
464 typedef enum {
465 pdf_quoteok= 0x001
466 } parsedomain_flags;
467
468 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
469 vbuf *vb, parsedomain_flags flags,
470 const byte *dgram, int dglen, int *cbyte_io, int max);
471 /* vb must already have been initialised; it will be reset if necessary.
472 * If there is truncation, vb->used will be set to 0; otherwise
473 * (if there is no error) vb will be null-terminated.
474 * If there is an error vb and *cbyte_io may be left indeterminate.
475 *
476 * serv may be -1 and qu may be 0 - they are used for error reporting only.
477 */
478
479 adns_status adns__findrr(adns_query qu, int serv,
480 const byte *dgram, int dglen, int *cbyte_io,
481 int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
482 int *ownermatchedquery_r);
483 /* Finds the extent and some of the contents of an RR in a datagram
484 * and does some checks. The datagram is *dgram, length dglen, and
485 * the RR starts at *cbyte_io (which is updated afterwards to point
486 * to the end of the RR).
487 *
488 * The type, class and RRdata length and start are returned iff
489 * the corresponding pointer variables are not null. type_r and
490 * class_r may not be null.
491 *
492 * If ownermatchedquery_r != 0 then the owner domain of this
493 * RR will be compared with that in the query (or, if the query
494 * has gone to a CNAME lookup, with the canonical name).
495 * In this case, *ownermatchedquery_r will be set to 0 or 1.
496 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
497 *
498 * If there is truncation then *type_r will be set to -1 and
499 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
500 * undefined.
501 *
502 * qu must obviously be non-null.
503 *
504 * If an error is returned then *type_r will be undefined too.
505 */
506
507 adns_status adns__findrr_anychk(adns_query qu, int serv,
508 const byte *dgram, int dglen, int *cbyte_io,
509 int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
510 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
511 int *eo_matched_r);
512 /* Like adns__findrr_checked, except that the datagram and
513 * owner to compare with can be specified explicitly.
514 *
515 * If the caller thinks they know what the owner of the RR ought to
516 * be they can pass in details in eo_*: this is another (or perhaps
517 * the same datagram), and a pointer to where the putative owner
518 * starts in that datagram. In this case *eo_matched_r will be set
519 * to 1 if the datagram matched or 0 if it did not. Either
520 * both eo_dgram and eo_matched_r must both be non-null, or they
521 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
522 * The eo datagram and contained owner domain MUST be valid and
523 * untruncated.
524 */
525
526 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
527
528 /* From event.c: */
529
530 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
531 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
532
533 void adns__autosys(adns_state ads, struct timeval now);
534 /* Make all the system calls we want to if the application wants us to. */
535
536 /* Useful static inline functions: */
537
538 static inline void timevaladd(struct timeval *tv_io, long ms) {
539 struct timeval tmp;
540 assert(ms>=0);
541 tmp= *tv_io;
542 tmp.tv_usec += (ms%1000)*1000000;
543 tmp.tv_sec += ms/1000;
544 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
545 *tv_io= tmp;
546 }
547
548 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
549 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
550 static inline int ctype_alpha(int c) {
551 return (c >= 'a' && c <= 'z') || (c >= 'A' || c <= 'Z');
552 }
553
554 /* Useful macros */
555
556 #define MEM_ROUND(sz) \
557 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
558 * sizeof(union maxalign) )
559
560 #define LIST_INIT(list) ((list).head= (list).tail= 0)
561
562 #define LIST_UNLINK_PART(list,node,part) \
563 do { \
564 if ((node)->part back) (node)->part back->part next= (node)->part next; \
565 else (list).head= (node)->part next; \
566 if ((node)->part next) (node)->part next->part back= (node)->part back; \
567 else (list).tail= (node)->part back; \
568 } while(0)
569
570 #define LIST_LINK_TAIL_PART(list,node,part) \
571 do { \
572 (node)->part next= 0; \
573 (node)->part back= (list).tail; \
574 if ((list).tail) (list).tail->part next= (node); else (list).head= (node); \
575 (list).tail= (node); \
576 } while(0)
577
578 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
579 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
580
581 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
582 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
583 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
584
585 #endif