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
;
39 /* Configuration and constants */
42 #define MAXSORTLIST 15
43 #define UDPMAXRETRIES 15
44 #define UDPRETRYMS 2000
46 #define LOCALRESOURCEMS 20
49 #define DNS_MAXUDP 512
50 #define DNS_MAXDOMAIN 255
51 #define DNS_HDRSIZE 12
52 #define DNS_CLASS_IN 1
54 #define DNS_INADDR_ARPA "in-addr", "arpa"
65 /* Shared data structures */
86 int dglen
, nsstart
, nscount
, arcount
;
96 void (*makefinal
)(adns_query qu
, void *data
);
97 /* Change memory management of *data.
98 * Previously, used alloc_interim, now use alloc_final.
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.
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.
111 * The RR should be stored at *store_r, of length qu->typei->rrsz.
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.
116 * nsstart is the offset of the authority section.
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.
124 /* Now come a number of hooks which are usually zero. They are used by
125 * query types which need special processing, like adns_rr_addr.
128 int (*initqtype
)(adns_state ads
, adns_queryflags flags
);
129 /* Returns the typecode (DNS, not adns_rr_type) for the initial
130 * query. The general code will always construct a query datagram
131 * for the owner domain specified in _submit.
132 * If !initqtype then (typeinfo->type & adns__rrt_typemask) is used.
135 adns_status (*begin
)(adns_state ads
, adns_query qu
, struct timeval now
);
136 /* Alternative `query start' function. If !begin then the general code
137 * will try to send the initial query datagram by UDP to a nameserver.
138 * If it returns an error then the original _submit will too; it may
139 * also choose to fail the query.
143 typedef struct allocnode
{
144 struct allocnode
*next
, *back
;
158 void (*callback
)(adns_query parent
, adns_query child
);
160 adns_rr_addr ptr_parent_addr
;
161 adns_rr_hostaddr
*hostaddr
;
167 enum { query_udp
, query_tcpwait
, query_tcpsent
, query_child
, query_done
} state
;
168 adns_query back
, next
, parent
;
169 struct { adns_query head
, tail
; } children
;
170 struct { adns_query back
, next
; } siblings
;
171 struct { allocnode
*head
, *tail
; } allocations
;
173 void *final_allocspace
;
175 const typeinfo
*typei
;
180 /* General-purpose messing-about buffer.
181 * Wherever a `big' interface is crossed, this may be corrupted/changed
182 * unless otherwise specified.
186 /* This is allocated when a query is submitted, to avoid being unable
187 * to relate errors to queries if we run out of memory. During
188 * query processing status, rrs is 0. cname is set if
189 * we found a cname (this corresponds to cname_dgram in the query
190 * structure). type is set from the word go. nrrs and rrs
191 * are set together, when we find how many rrs there are.
195 int cname_dglen
, cname_begin
;
196 /* If non-0, has been allocated using . */
198 int id
, flags
, udpretries
;
200 unsigned long udpsent
, tcpfailed
; /* bitmap indexed by server */
201 struct timeval timeout
;
207 * state Queue child id nextudpserver sentudp failedtcp
209 * udp NONE null >=0 0 zero zero
210 * udp timew null >=0 any nonzero zero
211 * udp NONE null >=0 any nonzero zero
213 * tcpwait timew null >=0 irrelevant zero any
214 * tcpsent timew null >=0 irrelevant zero any
216 * child childw set >=0 irrelevant irrelevant irrelevant
217 * done output null -1 irrelevant irrelevant irrelevant
219 * +------------------------+
220 * START -----> | udp/NONE |
221 * +------------------------+
223 * too big for UDP / UDP timeout \ \ send via UDP
224 * do this ASAP! / more retries \ \ do this ASAP!
226 * +---------------+ +-----------+
227 * | tcpwait/timew | ____ | udp/timew |
228 * +---------------+ \ +-----------+
230 * TCP conn'd; | | TCP died | | |
231 * send via TCP | | more | UDP timeout | |
232 * do this ASAP! | | servers | no more | |
233 * v | to try | retries | |
234 * +---------------+ | desired | |
235 * | tcpsent/timew | ____ | | |
236 * +---------------+ \| | |
237 * \ \ TCP died | TCP | |
238 * \ \ no more | timeout / |
242 * reply \ _| +------------------+ / reply
243 * \ | done/output FAIL | /
244 * \ +------------------+ /
247 * (..... got reply ....)
249 * need child query/ies / \ no child query
252 * +--------------+ +----------------+
253 * | child/childw | ----------------> | done/output OK |
254 * +--------------+ children done +----------------+
259 adns_initflags iflags
;
262 struct { adns_query head
, tail
; } timew
, childw
, output
;
263 int nextid
, udpsocket
, tcpsocket
;
264 vbuf tcpsend
, tcprecv
;
265 int nservers
, nsortlist
, tcpserver
;
266 enum adns__tcpstate
{ server_disconnected
, server_connecting
, server_ok
} tcpstate
;
267 struct timeval tcptimeout
;
268 adns_rr_addr servers
[MAXSERVERS
]; /* port fields will be 53 here */
270 struct in_addr6 base
, mask
;
271 } sortlist
[MAXSORTLIST
];
276 int adns__setnonblock(adns_state ads
, int fd
); /* => errno value */
278 /* From general.c: */
280 void adns__vdiag(adns_state ads
, const char *pfx
, adns_initflags prevent
,
281 int serv
, adns_query qu
, const char *fmt
, va_list al
);
283 void adns__debug(adns_state ads
, int serv
, adns_query qu
,
284 const char *fmt
, ...) PRINTFFORMAT(4,5);
285 void adns__warn(adns_state ads
, int serv
, adns_query qu
,
286 const char *fmt
, ...) PRINTFFORMAT(4,5);
287 void adns__diag(adns_state ads
, int serv
, adns_query qu
,
288 const char *fmt
, ...) PRINTFFORMAT(4,5);
290 int adns__vbuf_ensure(vbuf
*vb
, int want
);
291 int adns__vbuf_appendstr(vbuf
*vb
, const char *data
); /* does not include nul */
292 int adns__vbuf_append(vbuf
*vb
, const byte
*data
, int len
);
293 /* 1=>success, 0=>realloc failed */
294 void adns__vbuf_appendq(vbuf
*vb
, const byte
*data
, int len
);
295 void adns__vbuf_init(vbuf
*vb
);
296 void adns__vbuf_free(vbuf
*vb
);
298 const char *adns__diag_domain(adns_state ads
, int serv
, adns_query qu
,
299 vbuf
*vb
, const byte
*dgram
, int dglen
, int cbyte
);
300 /* Unpicks a domain in a datagram and returns a string suitable for
301 * printing it as. Never fails - if an error occurs, it will
302 * return some kind of string describing the error.
304 * serv may be -1 and qu may be 0. vb must have been initialised,
305 * and will be left in an arbitrary consistent state.
307 * Returns either vb->buf, or a pointer to a string literal. Do not modify
308 * vb before using the return value.
311 void adns__isort(void *array
, int nobjs
, int sz
, void *tempbuf
,
312 int (*needswap
)(void *context
, const void *a
, const void *b
),
314 /* Does an insertion sort of array which must contain nobjs objects
315 * each sz bytes long. tempbuf must point to a buffer at least
316 * sz bytes long. needswap should return !0 if a>b (strictly, ie
317 * wrong order) 0 if a<=b (ie, order is fine).
320 /* From transmit.c: */
322 adns_status
adns__mkquery(adns_state ads
, vbuf
*vb
, int *id_r
,
323 const char *owner
, int ol
,
324 const typeinfo
*typei
, adns_queryflags flags
);
325 /* Assembles a query packet in vb, and returns id at *id_r. */
327 adns_status
adns__mkquery_frdgram(adns_state ads
, vbuf
*vb
, int *id_r
,
328 const byte
*qd_dgram
, int qd_dglen
, int qd_begin
,
329 adns_rrtype type
, adns_queryflags flags
);
330 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
331 * That domain must be correct and untruncated.
334 adns_status
adns__subquery(adns_state ads
, adns_query parent
, vbuf
*vb
,
335 const byte
*qd_dgram
, int qd_dglen
, int qd_begin
,
336 adns_rrtype type
, adns_queryflags flags
,
337 struct timeval now
, const qcontext
*ctx
);
338 /* Constructs a query datagram using _mkquery_frdgram, as above, and then
339 * makes the query an internal one with parent qu and sends it off.
340 * vbuf is used as a buffer to construct the query, and will be overwritten.
343 void adns__query_tcp(adns_query qu
, struct timeval now
);
344 /* Query must be in state tcpwait/timew; it will be moved to a new state
345 * if possible and no further processing can be done on it for now.
346 * (Resulting state is one of tcpwait/timew (if server not connected),
347 * tcpsent/timew, child/childw or done/output.)
349 * adns__tcp_tryconnect should already have been called - _tcp
350 * will only use an existing connection (if there is one), which it
351 * may break. If the conn is lost then the caller is responsible for any
352 * reestablishment and retry.
355 void adns__query_udp(adns_query qu
, struct timeval now
);
356 /* Query must be in state udp/NONE; it will be moved to a new state,
357 * and no further processing can be done on it for now.
358 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
359 * tcpsent/timew, child/childw or done/output.)
364 int adns__internal_submit(adns_state ads
, adns_query
*query_r
,
365 const typeinfo
*typei
, vbuf
*qumsg_vb
, int id
,
366 adns_queryflags flags
, struct timeval now
,
367 adns_status failstat
, const qcontext
*ctx
);
368 /* Submits a query (for internal use, called during external submits).
370 * The new query is returned in *query_r, or we return adns_s_nomemory.
372 * The query datagram should already have been assembled in qumsg_vb;
373 * the memory for it is _taken over_ by this routine whether it
374 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
376 * If failstat is nonzero then if we are successful in creating the query
377 * it is immediately failed with code failstat (but _submit still succeds).
379 * *ctx is copied byte-for-byte into the query.
382 void *adns__alloc_interim(adns_query qu
, size_t sz
);
383 /* Allocates some memory, and records which query it came from
384 * and how much there was.
386 * If an error occurs in the query, all its memory is simply freed.
388 * If the query succeeds, one large buffer will be made which is
389 * big enough for all these allocations, and then adns__alloc_final
390 * will get memory from this buffer.
392 * _alloc_interim can fail (and return 0).
393 * The caller must ensure that the query is failed.
395 * adns__alloc_interim_{only,fail}(qu,0) will not return 0,
396 * but it will not necessarily return a distinct pointer each time.
399 void adns__transfer_interim(adns_query from
, adns_query to
, void *block
, size_t sz
);
400 /* Transfers an interim allocation from one query to another, so that
401 * the `to' query will have room for the data when we get to makefinal
402 * and so that the free will happen when the `to' query is freed
403 * rather than the `from' query.
405 * It is legal to call adns__transfer_interim with a null pointer; this
409 void *adns__alloc_mine(adns_query qu
, size_t sz
);
410 /* Like _interim, but does not record the length for later
411 * copying into the answer. This just ensures that the memory
412 * will be freed when we're done with the query.
415 void *adns__alloc_final(adns_query qu
, size_t sz
);
416 /* Cannot fail, and cannot return 0.
419 void adns__makefinal_block(adns_query qu
, void **blpp
, size_t sz
);
420 void adns__makefinal_str(adns_query qu
, char **strp
);
422 void adns__reset_cnameonly(adns_query qu
);
423 /* Resets all of the memory management stuff etc. to
424 * take account of only the CNAME. Used when we find an error somewhere
425 * and want to just report the error (with perhaps CNAME info), and also
426 * when we're halfway through RRs in a datagram and discover that we
427 * need to retry the query.
430 void adns__query_done(adns_query qu
);
431 void adns__query_fail(adns_query qu
, adns_status stat
);
435 void adns__procdgram(adns_state ads
, const byte
*dgram
, int len
,
436 int serv
, struct timeval now
);
440 const typeinfo
*adns__findtype(adns_rrtype type
);
449 int dglen
, max
, cbyte
, namelen
;
453 void adns__findlabel_start(findlabel_state
*fls
, adns_state ads
,
454 int serv
, adns_query qu
,
455 const byte
*dgram
, int dglen
, int max
,
456 int dmbegin
, int *dmend_rlater
);
457 /* Finds labels in a domain in a datagram.
459 * Call this routine first.
460 * dmend_rlater may be null. ads (and of course fls) may not be.
461 * serv may be -1, qu may be null - they are for error reporting.
464 adns_status
adns__findlabel_next(findlabel_state
*fls
, int *lablen_r
, int *labstart_r
);
465 /* Then, call this one repeatedly.
467 * It will return adns_s_ok if all is well, and tell you the length
468 * and start of successive labels. labstart_r may be null, but
469 * lablen_r must not be.
471 * After the last label, it will return with *lablen_r zero.
472 * Do not then call it again; instead, just throw away the findlabel_state.
474 * *dmend_rlater will have been set to point to the next part of
475 * the datagram after the label (or after the uncompressed part,
476 * if compression was used). *namelen_rlater will have been set
477 * to the length of the domain name (total length of labels plus
478 * 1 for each intervening dot).
480 * If the datagram appears to be truncated, *lablen_r will be -1.
481 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
482 * Do not call _next again.
484 * There may also be errors, in which case *dmend_rlater,
485 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
486 * Do not then call findlabel_next again.
493 adns_status
adns__parse_domain(adns_state ads
, int serv
, adns_query qu
,
494 vbuf
*vb
, parsedomain_flags flags
,
495 const byte
*dgram
, int dglen
, int *cbyte_io
, int max
);
496 /* vb must already have been initialised; it will be reset if necessary.
497 * If there is truncation, vb->used will be set to 0; otherwise
498 * (if there is no error) vb will be null-terminated.
499 * If there is an error vb and *cbyte_io may be left indeterminate.
501 * serv may be -1 and qu may be 0 - they are used for error reporting only.
504 adns_status
adns__findrr(adns_query qu
, int serv
,
505 const byte
*dgram
, int dglen
, int *cbyte_io
,
506 int *type_r
, int *class_r
, int *rdlen_r
, int *rdstart_r
,
507 int *ownermatchedquery_r
);
508 /* Finds the extent and some of the contents of an RR in a datagram
509 * and does some checks. The datagram is *dgram, length dglen, and
510 * the RR starts at *cbyte_io (which is updated afterwards to point
511 * to the end of the RR).
513 * The type, class and RRdata length and start are returned iff
514 * the corresponding pointer variables are not null. type_r and
515 * class_r may not be null.
517 * If ownermatchedquery_r != 0 then the owner domain of this
518 * RR will be compared with that in the query (or, if the query
519 * has gone to a CNAME lookup, with the canonical name).
520 * In this case, *ownermatchedquery_r will be set to 0 or 1.
521 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
523 * If there is truncation then *type_r will be set to -1 and
524 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
527 * qu must obviously be non-null.
529 * If an error is returned then *type_r will be undefined too.
532 adns_status
adns__findrr_anychk(adns_query qu
, int serv
,
533 const byte
*dgram
, int dglen
, int *cbyte_io
,
534 int *type_r
, int *class_r
, int *rdlen_r
, int *rdstart_r
,
535 const byte
*eo_dgram
, int eo_dglen
, int eo_cbyte
,
537 /* Like adns__findrr_checked, except that the datagram and
538 * owner to compare with can be specified explicitly.
540 * If the caller thinks they know what the owner of the RR ought to
541 * be they can pass in details in eo_*: this is another (or perhaps
542 * the same datagram), and a pointer to where the putative owner
543 * starts in that datagram. In this case *eo_matched_r will be set
544 * to 1 if the datagram matched or 0 if it did not. Either
545 * both eo_dgram and eo_matched_r must both be non-null, or they
546 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
547 * The eo datagram and contained owner domain MUST be valid and
551 int vbuf__append_quoted1035(vbuf
*vb
, const byte
*buf
, int len
);
555 void adns__tcp_broken(adns_state ads
, const char *what
, const char *why
);
556 void adns__tcp_tryconnect(adns_state ads
, struct timeval now
);
558 void adns__autosys(adns_state ads
, struct timeval now
);
559 /* Make all the system calls we want to if the application wants us to. */
561 /* Useful static inline functions: */
563 static inline void timevaladd(struct timeval
*tv_io
, long ms
) {
567 tmp
.tv_usec
+= (ms
%1000)*1000000;
568 tmp
.tv_sec
+= ms
/1000;
569 if (tmp
.tv_usec
>= 1000000) { tmp
.tv_sec
++; tmp
.tv_usec
-= 1000; }
573 static inline int ctype_whitespace(int c
) { return c
==' ' || c
=='\n' || c
=='\t'; }
574 static inline int ctype_digit(int c
) { return c
>='0' && c
<='9'; }
575 static inline int ctype_alpha(int c
) {
576 return (c
>= 'a' && c
<= 'z') || (c
>= 'A' || c
<= 'Z');
581 #define MEM_ROUND(sz) \
582 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
583 * sizeof(union maxalign) )
585 #define LIST_INIT(list) ((list).head= (list).tail= 0)
587 #define LIST_UNLINK_PART(list,node,part) \
589 if ((node)->part back) (node)->part back->part next= (node)->part next; \
590 else (list).head= (node)->part next; \
591 if ((node)->part next) (node)->part next->part back= (node)->part back; \
592 else (list).tail= (node)->part back; \
595 #define LIST_LINK_TAIL_PART(list,node,part) \
597 (node)->part next= 0; \
598 (node)->part back= (list).tail; \
599 if ((list).tail) (list).tail->part next= (node); else (list).head= (node); \
600 (list).tail= (node); \
603 #define LIST_UNLINK(list,node) LIST_UNLINK_PART(list,node,)
604 #define LIST_LINK_TAIL(list,node) LIST_LINK_TAIL_PART(list,node,)
606 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
607 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
608 #define GET_W(cb,tv) ((tv)=0, (tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))