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,
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.
113 typedef struct allocnode {
114 struct allocnode *next;
128 enum { query_udp, query_tcpwait, query_tcpsent, query_child, query_done } state;
129 adns_query back, next, parent;
130 struct { adns_query head, tail; } children;
131 struct { adns_query back, next; } siblings;
132 struct allocnode *allocations;
134 void *final_allocspace;
136 const typeinfo *typei;
141 /* General-purpose messing-about buffer.
142 * Wherever a `big' interface is crossed, this may be corrupted/changed
143 * unless otherwise specified.
147 /* This is allocated when a query is submitted, to avoid being unable
148 * to relate errors to queries if we run out of memory. During
149 * query processing status, rrs is 0. cname is set if
150 * we found a cname (this corresponds to cname_dgram in the query
151 * structure). type is set from the word go. nrrs and rrs
152 * are set together, when we find how many rrs there are.
156 int cname_dglen, cname_begin;
157 /* If non-0, has been allocated using . */
159 int id, flags, udpretries;
161 unsigned long udpsent, tcpfailed; /* bitmap indexed by server */
162 struct timeval timeout;
167 * state Queue child id nextudpserver sentudp failedtcp
169 * udp NONE null >=0 0 zero zero
170 * udp timew null >=0 any nonzero zero
171 * udp NONE null >=0 any nonzero zero
173 * tcpwait timew null >=0 irrelevant zero any
174 * tcpsent timew null >=0 irrelevant zero any
176 * child childw set >=0 irrelevant irrelevant irrelevant
177 * done output null -1 irrelevant irrelevant irrelevant
179 * +------------------------+
180 * START -----> | udp/NONE |
181 * +------------------------+
183 * too big for UDP / UDP timeout \ \ send via UDP
184 * do this ASAP! / more retries \ \ do this ASAP!
186 * +---------------+ +-----------+
187 * | tcpwait/timew | ____ | udp/timew |
188 * +---------------+ \ +-----------+
190 * TCP conn'd; | | TCP died | | |
191 * send via TCP | | more | UDP timeout | |
192 * do this ASAP! | | servers | no more | |
193 * v | to try | retries | |
194 * +---------------+ | desired | |
195 * | tcpsent/timew | ____ | | |
196 * +---------------+ \| | |
197 * \ \ TCP died | TCP | |
198 * \ \ no more | timeout / |
202 * reply \ _| +------------------+ / reply
203 * \ | done/output FAIL | /
204 * \ +------------------+ /
207 * (..... got reply ....)
209 * need child query/ies / \ no child query
212 * +--------------+ +----------------+
213 * | child/childw | ----------------> | done/output OK |
214 * +--------------+ children done +----------------+
219 adns_initflags iflags;
221 struct { adns_query head, tail; } timew, childw, output;
222 int nextid, udpsocket, tcpsocket;
223 vbuf tcpsend, tcprecv;
224 int nservers, tcpserver;
225 enum adns__tcpstate { server_disconnected, server_connecting, server_ok } tcpstate;
226 struct timeval tcptimeout;
229 } servers[MAXSERVERS];
234 int adns__setnonblock(adns_state ads, int fd); /* => errno value */
236 /* From general.c: */
238 void adns__vdiag(adns_state ads, const char *pfx, adns_initflags prevent,
239 int serv, adns_query qu, const char *fmt, va_list al);
241 void adns__debug(adns_state ads, int serv, adns_query qu,
242 const char *fmt, ...) PRINTFFORMAT(4,5);
243 void adns__warn(adns_state ads, int serv, adns_query qu,
244 const char *fmt, ...) PRINTFFORMAT(4,5);
245 void adns__diag(adns_state ads, int serv, adns_query qu,
246 const char *fmt, ...) PRINTFFORMAT(4,5);
248 int adns__vbuf_ensure(vbuf *vb, int want);
249 int adns__vbuf_appendstr(vbuf *vb, const char *data); /* does not include nul */
250 int adns__vbuf_append(vbuf *vb, const byte *data, int len);
251 /* 1=>success, 0=>realloc failed */
252 void adns__vbuf_appendq(vbuf *vb, const byte *data, int len);
253 void adns__vbuf_init(vbuf *vb);
254 void adns__vbuf_free(vbuf *vb);
256 const char *adns__diag_domain(adns_state ads, int serv, adns_query qu, vbuf *vb,
257 int flags, const byte *dgram, int dglen, int cbyte);
258 /* Unpicks a domain in a datagram and returns a string suitable for
259 * printing it as. Never fails - if an error occurs, it will
260 * return some kind of string describing the error.
262 * serv may be -1 and qu may be 0. vb must have been initialised,
263 * and will be left in an arbitrary consistent state.
265 * Returns either vb->buf, or a pointer to a string literal. Do not modify
266 * vb before using the return value.
269 /* From transmit.c: */
271 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
272 const char *owner, int ol,
273 const typeinfo *typei, adns_queryflags flags);
274 /* Assembles a query packet in vb, and returns id at *id_r. */
276 void adns__query_tcp(adns_query qu, struct timeval now);
277 /* Query must be in state tcpwait/timew; it will be moved to a new state
278 * if possible and no further processing can be done on it for now.
279 * (Resulting state is one of tcpwait/timew (if server not connected),
280 * tcpsent/timew, child/childw or done/output.)
282 * adns__tcp_tryconnect should already have been called - _tcp
283 * will only use an existing connection (if there is one), which it
284 * may break. If the conn list lost then the caller is responsible for any
285 * reestablishment and retry.
288 void adns__query_udp(adns_query qu, struct timeval now);
289 /* Query must be in state udp/NONE; it will be moved to a new state,
290 * and no further processing can be done on it for now.
291 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
292 * tcpsent/timew, child/childw or done/output.)
297 int adns__internal_submit(adns_state ads, adns_query *query_r,
298 const typeinfo *typei, vbuf *qumsg_vb, int id,
299 adns_queryflags flags, struct timeval now,
300 adns_status failstat, const qcontext *ctx);
301 /* Submits a query (for internal use, called during external submits).
303 * The new query is returned in *query_r, or we return adns_s_nomemory.
305 * The query datagram should already have been assembled in qumsg_vb;
306 * the memory for it is _taken over_ by this routine whether it
307 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
309 * If failstat is nonzero then if we are successful in creating the query
310 * it is immediately failed with code failstat (but _submit still succeds).
312 * ctx is copied byte-for-byte into the query.
315 void *adns__alloc_interim(adns_query qu, size_t sz);
316 /* Allocates some memory, and records which query it came from
317 * and how much there was.
319 * If an error occurs in the query, all its memory is simply freed.
321 * If the query succeeds, one large buffer will be made which is
322 * big enough for all these allocations, and then adns__alloc_final
323 * will get memory from this buffer.
325 * _alloc_interim can fail, in which case it will fail the query too,
326 * so nothing more need be done with it.
328 * adns__alloc_interim(qu,0) will not return 0, but it will not
329 * necessarily return a distinct pointer each time.
332 void *adns__alloc_mine(adns_query qu, size_t sz);
333 /* Like _interim, but does not record the length for later
334 * copying into the answer. This just ensures that the memory
335 * will be freed when we're done with the query.
338 void *adns__alloc_final(adns_query qu, size_t sz);
339 /* Cannot fail, and cannot return 0.
342 void adns__makefinal_block(adns_query qu, void **blpp, size_t sz);
343 void adns__makefinal_str(adns_query qu, char **strp);
345 void adns__reset_cnameonly(adns_query qu);
346 /* Resets all of the memory management stuff etc. to
347 * take account of only the CNAME. Used when we find an error somewhere
348 * and want to just report the error (with perhaps CNAME info), and also
349 * when we're halfway through RRs in a datagram and discover that we
350 * need to retry the query.
353 void adns__query_done(adns_query qu);
354 void adns__query_fail(adns_query qu, adns_status stat);
358 void adns__procdgram(adns_state ads, const byte *dgram, int len,
359 int serv, struct timeval now);
363 const typeinfo *adns__findtype(adns_rrtype type);
372 int dglen, max, cbyte, namelen;
376 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
377 int serv, adns_query qu,
378 const byte *dgram, int dglen, int max,
379 int dmbegin, int *dmend_rlater);
380 /* Finds labels in a domain in a datagram.
382 * Call this routine first.
383 * dmend_rlater may be null. ads (and of course fls) may not be.
384 * serv may be -1, qu may be null - they are for error reporting.
387 adns_status adns__findlabel_next(findlabel_state *fls, int *lablen_r, int *labstart_r);
388 /* Then, call this one repeatedly.
390 * It will return adns_s_ok if all is well, and tell you the length
391 * and start of successive labels. labstart_r may be null, but
392 * lablen_r must not be.
394 * After the last label, it will return with *lablen_r zero.
395 * Do not then call it again; instead, just throw away the findlabel_state.
397 * *dmend_rlater will have been set to point to the next part of
398 * the datagram after the label (or after the uncompressed part,
399 * if compression was used). *namelen_rlater will have been set
400 * to the length of the domain name (total length of labels plus
401 * 1 for each intervening dot).
403 * If the datagram appears to be truncated, *lablen_r will be -1.
404 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
405 * Do not call _next again.
407 * There may also be errors, in which case *dmend_rlater,
408 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
409 * Do not then call findlabel_next again.
412 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
414 const byte *dgram, int dglen, int *cbyte_io, int max);
415 /* vb must already have been initialised; it will be reset if necessary.
416 * If there is truncation, vb->used will be set to 0; otherwise
417 * (if there is no error) vb will be null-terminated.
418 * If there is an error vb and *cbyte_io may be left indeterminate.
420 * serv may be -1 and qu may be 0 - they are used for error reporting only.
423 adns_status adns__findrr(adns_query qu, int serv,
424 const byte *dgram, int dglen, int *cbyte_io,
425 int *type_r, int *class_r, int *rdlen_r, int *rdstart_r,
426 int *ownermatchedquery_r);
427 /* Finds the extent and some of the contents of an RR in a datagram
428 * and does some checks. The datagram is *dgram, length dglen, and
429 * the RR starts at *cbyte_io (which is updated afterwards to point
430 * to the end of the RR).
432 * The type, class and RRdata length and start are returned iff
433 * the corresponding pointer variables are not null. type_r and
434 * class_r may not be null.
436 * If ownermatchedquery_r != 0 then the owner domain of this
437 * RR will be compared with that in the query (or, if the query
438 * has gone to a CNAME lookup, with the canonical name).
439 * In this case, *ownermatchedquery_r will be set to 0 or 1.
440 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
442 * If there is truncation then *type_r will be set to -1 and
443 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
446 * qu must obviously be non-null.
448 * If an error is returned then *type_r will be undefined too.
451 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len);
455 void adns__tcp_broken(adns_state ads, const char *what, const char *why);
456 void adns__tcp_tryconnect(adns_state ads, struct timeval now);
458 void adns__autosys(adns_state ads, struct timeval now);
459 /* Make all the system calls we want to if the application wants us to. */
461 /* Useful static inline functions: */
463 static inline void timevaladd(struct timeval *tv_io, long ms) {
467 tmp.tv_usec += (ms%1000)*1000000;
468 tmp.tv_sec += ms/1000;
469 if (tmp.tv_usec >= 1000000) { tmp.tv_sec++; tmp.tv_usec -= 1000; }
473 static inline int ctype_whitespace(int c) { return c==' ' || c=='\n' || c=='\t'; }
474 static inline int ctype_digit(int c) { return c>='0' && c<='9'; }
475 static inline int ctype_alpha(int c) {
476 return (c >= 'a' && c <= 'z') || (c >= 'A' || c <= 'Z');
481 #define MEM_ROUND(sz) \
482 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
483 * sizeof(union maxalign) )
485 #define LIST_INIT(list) ((list).head= (list).tail= 0)
487 #define LIST_UNLINK_PART(list,node,part) \
489 if ((node)->back) (node)->back->part next= (node)->part next; \
490 else (list).head= (node)->part next; \
491 if ((node)->next) (node)->next->part back= (node)->part back; \
492 else (list).tail= (node)->part back; \
495 #define LIST_LINK_TAIL_PART(list,node,part) \
497 (node)->part next= 0; \
498 (node)->part back= (list).tail; \
499 if ((list).tail) (list).tail->part next= (node); else (list).part head= (node); \
500 (list).tail= (node); \
503 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
504 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
506 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
507 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
508 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))