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
9 * Copyright (C) 1997-2000,2003,2006,2014 Ian Jackson
10 * Copyright (C) 2014 Mark Wooding
11 * Copyright (C) 1999-2000,2003,2006 Tony Finch
12 * Copyright (C) 1991 Massachusetts Institute of Technology
13 * (See the file INSTALL for full details.)
15 * This program is free software; you can redistribute it and/or modify
16 * it under the terms of the GNU General Public License as published by
17 * the Free Software Foundation; either version 3, or (at your option)
20 * This program is distributed in the hope that it will be useful,
21 * but WITHOUT ANY WARRANTY; without even the implied warranty of
22 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 * GNU General Public License for more details.
25 * You should have received a copy of the GNU General Public License
26 * along with this program; if not, write to the Free Software Foundation.
29 #ifndef ADNS_INTERNAL_H_INCLUDED
30 #define ADNS_INTERNAL_H_INCLUDED
33 typedef unsigned char byte
;
46 #define ADNS_FEATURE_MANYAF
50 #ifdef ADNS_REGRESS_TEST
51 # include "hredirect.h"
54 /* Configuration and constants */
57 #define MAXSORTLIST 15
58 #define UDPMAXRETRIES 15
59 #define UDPRETRYMS 2000
60 #define TCPWAITMS 30000
61 #define TCPCONNMS 14000
62 #define TCPIDLEMS 30000
63 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
66 #define DNS_MAXUDP 512
67 #define DNS_MAXLABEL 63
68 #define DNS_MAXDOMAIN 255
69 #define DNS_HDRSIZE 12
70 #define DNS_IDOFFSET 0
71 #define DNS_CLASS_IN 1
73 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
75 /* Some preprocessor hackery */
77 #define GLUE(x, y) GLUE_(x, y)
78 #define GLUE_(x, y) x##y
80 /* C99 macro `...' must match at least one argument, so the naive definition
81 * `#define CAR(car, ...) car' won't work. But it's easy to arrange for the
82 * tail to be nonempty if we're just going to discard it anyway. */
83 #define CAR(...) CAR_(__VA_ARGS__, _)
84 #define CAR_(car, ...) car
86 /* Extracting the tail of an argument list is rather more difficult. The
87 * following trick is based on one by Laurent Deniau to count the number of
88 * arguments to a macro, simplified in two ways: (a) it only handles up to
89 * eight arguments, and (b) it only needs to distinguish the one-argument
90 * case from many arguments. */
91 #define CDR(...) CDR_(__VA_ARGS__, m, m, m, m, m, m, m, 1, _)(__VA_ARGS__)
92 #define CDR_(_1, _2, _3, _4, _5, _6, _7, _8, n, ...) CDR_##n
94 #define CDR_m(_, ...) __VA_ARGS__
100 } consistency_checks
;
112 adns__qf_addr_answer
= 0x01000000,/* addr query received an answer */
113 adns__qf_addr_cname
= 0x02000000 /* addr subquery performed on cname */
116 /* Shared data structures */
128 int dglen
, nsstart
, nscount
, arcount
;
132 #define MAXREVLABELS 34 /* keep in sync with addrfam! */
133 struct revparse_state
{
134 uint16_t labstart
[MAXREVLABELS
];
135 uint8_t lablen
[MAXREVLABELS
];
138 union checklabel_state
{
139 struct revparse_state ptr
;
144 void (*callback
)(adns_query parent
, adns_query child
);
148 adns_rrtype rev_rrtype
;
154 } tinfo
; /* type-specific state for the query itself: zero-init if you
155 * don't know better. */
158 adns_rr_hostaddr
*hostaddr
;
159 } pinfo
; /* state for use by parent's callback function */
162 typedef struct typeinfo
{
168 void (*makefinal
)(adns_query qu
, void *data
);
169 /* Change memory management of *data.
170 * Previously, used alloc_interim, now use alloc_final.
173 adns_status (*convstring
)(vbuf
*vb
, const void *data
);
174 /* Converts the RR data to a string representation in vbuf.
175 * vbuf will be appended to (it must have been initialised),
176 * and will not be null-terminated by convstring.
179 adns_status (*parse
)(const parseinfo
*pai
, int cbyte
,
180 int max
, void *store_r
);
181 /* Parse one RR, in dgram of length dglen, starting at cbyte and
182 * extending until at most max.
184 * The RR should be stored at *store_r, of length qu->typei->getrrsz().
186 * If there is an overrun which might indicate truncation, it should set
187 * *rdstart to -1; otherwise it may set it to anything else positive.
189 * nsstart is the offset of the authority section.
192 int (*diff_needswap
)(adns_state ads
,const void *datap_a
,const void *datap_b
);
193 /* Returns !0 if RR a should be strictly after RR b in the sort order,
194 * 0 otherwise. Must not fail.
197 adns_status (*checklabel
)(adns_state ads
, adns_queryflags flags
,
198 union checklabel_state
*cls
, qcontext
*ctx
,
199 int labnum
, const char *dgram
,
200 int labstart
, int lablen
);
201 /* Check a label from the query domain string. The label is not
202 * necessarily null-terminated. The hook can refuse the query's submission
203 * by returning a nonzero status. State can be stored in *cls between
204 * calls, and useful information can be stashed in ctx->tinfo, to be stored
205 * with the query (e.g., it will be available to the parse hook). This
206 * hook can detect a first call because labnum is zero, and a final call
207 * because lablen is zero.
210 void (*postsort
)(adns_state ads
, void *array
, int nrrs
, int rrsz
,
211 const struct typeinfo
*typei
);
212 /* Called immediately after the RRs have been sorted, and may rearrange
213 * them. (This is really for the benefit of SRV's bizarre weighting
214 * stuff.) May be 0 to mean nothing needs to be done.
217 int (*getrrsz
)(const struct typeinfo
*typei
, adns_rrtype type
);
218 /* Return the output resource-record element size; if this is null, then
219 * the rrsz member can be used.
222 void (*query_send
)(adns_query qu
, struct timeval now
);
223 /* Send the query to nameservers, and hook it into the appropriate queue.
224 * Normal behaviour is to call adns__query_send, but this can be overridden
225 * for special effects.
229 adns_status
adns__ckl_hostname(adns_state ads
, adns_queryflags flags
,
230 union checklabel_state
*cls
,
231 qcontext
*ctx
, int labnum
,
232 const char *dgram
, int labstart
, int lablen
);
233 /* implemented in query.c, used by types.c as default
234 * and as part of implementation for some fancier types
235 * doesn't require any state */
237 typedef struct allocnode
{
238 struct allocnode
*next
, *back
;
253 enum { query_tosend
, query_tcpw
, query_childw
, query_done
} state
;
254 adns_query back
, next
, parent
;
255 struct { adns_query head
, tail
; } children
;
256 struct { adns_query back
, next
; } siblings
;
257 struct { allocnode
*head
, *tail
; } allocations
;
258 int interim_allocd
, preserved_allocd
;
259 void *final_allocspace
;
261 const typeinfo
*typei
;
266 /* General-purpose messing-about buffer.
267 * Wherever a `big' interface is crossed, this may be corrupted/changed
268 * unless otherwise specified.
272 /* This is allocated when a query is submitted, to avoid being unable
273 * to relate errors to queries if we run out of memory. During
274 * query processing status, rrs is 0. cname is set if
275 * we found a cname (this corresponds to cname_dgram in the query
276 * structure). type is set from the word go. nrrs and rrs
277 * are set together, when we find how many rrs there are.
278 * owner is set during querying unless we're doing searchlist,
279 * in which case it is set only when we find an answer.
283 int cname_dglen
, cname_begin
;
284 /* If non-0, has been allocated using . */
287 int search_origlen
, search_pos
, search_doneabs
;
288 /* Used by the searching algorithm. The query domain in textual form
289 * is copied into the vbuf, and _origlen set to its length. Then
290 * we walk the searchlist, if we want to. _pos says where we are
291 * (next entry to try), and _doneabs says whether we've done the
292 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
293 * but not done yet). If flags doesn't have adns_qf_search then
294 * the vbuf is initialised but empty and everything else is zero.
297 int id
, flags
, retries
;
299 unsigned long udpsent
; /* bitmap indexed by server */
300 struct timeval timeout
;
301 time_t expires
; /* Earliest expiry time of any record we used. */
307 * state Queue child id nextudpserver udpsent tcpfailed
309 * tosend NONE null >=0 0 zero zero
310 * tosend udpw null >=0 any nonzero zero
311 * tosend NONE null >=0 any nonzero zero
313 * tcpw tcpw null >=0 irrelevant any any
315 * child childw set >=0 irrelevant irrelevant irrelevant
316 * child NONE null >=0 irrelevant irrelevant irrelevant
317 * done output null -1 irrelevant irrelevant irrelevant
319 * Queries are only not on a queue when they are actually being processed.
320 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
321 * iff the tcp connection is in state server_ok.
323 * Internal queries (from adns__submit_internal) end up on intdone
324 * instead of output, and the callbacks are made on the way out of
325 * adns, to avoid reentrancy hazards.
327 * +------------------------+
328 * START -----> | tosend/NONE |
329 * +------------------------+
331 * too big for UDP / UDP timeout \ \ send via UDP
332 * send via TCP / more retries \ \
333 * when conn'd / desired \ \
336 * +-----------+ +-------------+
337 * | tcpw/tcpw | ________ | tosend/udpw |
338 * +-----------+ \ +-------------+
339 * | | | UDP timeout | |
342 * \ | TCP died | desired | |
344 * \ \ servers | TCP / |
345 * \ \ to try | timeout / |
347 * reply \ _| +------------------+ / reply
348 * \ | done/output FAIL | /
349 * \ +------------------+ /
352 * (..... got reply ....)
354 * need child query/ies / \ no child query
357 * +---------------+ +----------------+
358 * | childw/childw | ----------------> | done/output OK |
359 * +---------------+ children done +----------------+
363 struct query_queue
{ adns_query head
, tail
; };
368 adns_initflags iflags
;
369 adns_logcallbackfn
*logfn
;
372 struct query_queue udpw
, tcpw
, childw
, output
, intdone
;
373 adns_query forallnext
;
374 int nextid
, tcpsocket
;
375 struct udpsocket
{ int af
; int fd
; } udpsockets
[MAXUDP
];
377 vbuf tcpsend
, tcprecv
;
378 int nservers
, nsortlist
, nsearchlist
, searchndots
, tcpserver
, tcprecv_skip
;
379 enum adns__tcpstate
{
380 server_disconnected
, server_connecting
,
381 server_ok
, server_broken
383 struct timeval tcptimeout
;
384 /* This will have tv_sec==0 if it is not valid. It will always be
385 * valid if tcpstate _connecting. When _ok, it will be nonzero if
386 * we are idle (ie, tcpw queue is empty), in which case it is the
387 * absolute time when we will close the connection.
389 struct sigaction stdsigpipe
;
391 struct pollfd pollfds_buf
[MAX_POLLFDS
];
392 adns_rr_addr servers
[MAXSERVERS
];
394 adns_sockaddr base
, mask
;
395 } sortlist
[MAXSORTLIST
];
397 unsigned config_report_unknown
:1;
398 unsigned short rand48xsubi
[3];
401 /* From addrfam.c: */
403 extern int adns__addrs_equal_raw(const struct sockaddr
*a
,
404 int bf
, const void *b
);
405 /* Returns nonzero a's family is bf and a's protocol address field
406 * refers to the same protocol address as that stored at ba.
409 extern int adns__addrs_equal(const adns_sockaddr
*a
,
410 const adns_sockaddr
*b
);
411 /* Returns nonzero if the two refer to the same protocol address
412 * (disregarding port, IPv6 scope, etc).
415 extern int adns__sockaddrs_equal(const struct sockaddr
*sa
,
416 const struct sockaddr
*sb
);
417 /* Return nonzero if the two socket addresses are equal (in all significant
421 extern int adns__addr_width(int af
);
422 /* Return the width of addresses of family af, in bits. */
424 extern void adns__prefix_mask(adns_sockaddr
*sa
, int len
);
425 /* Stores in sa's protocol address field an address mask for address
426 * family af, whose first len bits are set and the remainder are
427 * clear. On entry, sa's af field must be set. This is what you want
428 * for converting a prefix length into a netmask.
431 extern int adns__guess_prefix_length(const adns_sockaddr
*addr
);
432 /* Given a network base address, guess the appropriate prefix length based on
433 * the appropriate rules for the address family (e.g., for IPv4, this uses
434 * the old address classes).
437 extern int adns__addr_matches(int af
, const void *addr
,
438 const adns_sockaddr
*base
,
439 const adns_sockaddr
*mask
);
440 /* Return nonzero if the protocol address specified by af and addr
441 * lies within the network specified by base and mask.
444 extern void adns__addr_inject(const void *a
, adns_sockaddr
*sa
);
445 /* Injects the protocol address *a into the socket adress sa. Assumes
446 * that sa->sa_family is already set correctly.
449 extern const void *adns__sockaddr_addr(const struct sockaddr
*sa
);
450 /* Returns the address of the protocol address field in sa.
453 char *adns__sockaddr_ntoa(const struct sockaddr
*sa
, char *buf
);
454 /* Converts sa to a string, and writes it to buf, which must be at
455 * least ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Returns buf;
459 extern int adns__make_reverse_domain(const struct sockaddr
*sa
,
461 char **buf_io
, size_t bufsz
,
463 /* Construct a reverse domain string, given a socket address and a parent
464 * zone. If zone is null, then use the standard reverse-lookup zone for the
465 * address family. If the length of the resulting string is no larger than
466 * bufsz, then the result is stored starting at *buf_io; otherwise a new
467 * buffer is allocated is used, and a pointer to it is stored in both *buf_io
468 * and *buf_free_r (the latter of which should be null on entry). If
469 * something goes wrong, then an errno value is returned: ENOSYS if the
470 * address family of sa isn't recognized, or ENOMEM if the attempt to
471 * allocate an output buffer failed.
474 extern bool adns__revparse_label(struct revparse_state
*rps
, int labnum
,
476 int labstart
, int lablen
);
477 /* Parse a label in a reverse-domain name, given its index labnum (starting
478 * from zero), a pointer to its contents (which need not be null-terminated),
479 * and its length. The state in *rps is initialized implicitly when labnum
482 * Returns 1 if the parse is proceeding successfully, 0 if the domain
483 * name is definitely invalid and the parse must be abandoned.
486 extern bool adns__revparse_done(struct revparse_state
*rps
,
487 const char *dgram
, int nlabels
,
488 adns_rrtype
*rrtype_r
, adns_sockaddr
*addr_r
);
489 /* Finishes parsing a reverse-domain name, given the total number of
490 * labels in the name. On success, fills in the af and protocol
491 * address in *addr_r, and the forward query type in *rrtype_r
492 * (because that turns out to be useful). Returns 1 if the parse
498 int adns__setnonblock(adns_state ads
, int fd
); /* => errno value */
500 /* From general.c: */
502 void adns__vlprintf(adns_state ads
, const char *fmt
, va_list al
);
503 void adns__lprintf(adns_state ads
, const char *fmt
,
504 ...) PRINTFFORMAT(2,3);
506 void adns__vdiag(adns_state ads
, const char *pfx
, adns_initflags prevent
,
507 int serv
, adns_query qu
, const char *fmt
, va_list al
);
509 void adns__debug(adns_state ads
, int serv
, adns_query qu
,
510 const char *fmt
, ...) PRINTFFORMAT(4,5);
511 void adns__warn(adns_state ads
, int serv
, adns_query qu
,
512 const char *fmt
, ...) PRINTFFORMAT(4,5);
513 void adns__diag(adns_state ads
, int serv
, adns_query qu
,
514 const char *fmt
, ...) PRINTFFORMAT(4,5);
516 int adns__vbuf_ensure(vbuf
*vb
, int want
);
517 int adns__vbuf_appendstr(vbuf
*vb
, const char *data
); /* doesn't include nul */
518 int adns__vbuf_append(vbuf
*vb
, const byte
*data
, int len
);
519 /* 1=>success, 0=>realloc failed */
520 void adns__vbuf_appendq(vbuf
*vb
, const byte
*data
, int len
);
521 void adns__vbuf_init(vbuf
*vb
);
522 void adns__vbuf_free(vbuf
*vb
);
524 const char *adns__diag_domain(adns_state ads
, int serv
, adns_query qu
,
526 const byte
*dgram
, int dglen
, int cbyte
);
527 /* Unpicks a domain in a datagram and returns a string suitable for
528 * printing it as. Never fails - if an error occurs, it will
529 * return some kind of string describing the error.
531 * serv may be -1 and qu may be 0. vb must have been initialised,
532 * and will be left in an arbitrary consistent state.
534 * Returns either vb->buf, or a pointer to a string literal. Do not modify
535 * vb before using the return value.
538 int adns__getrrsz_default(const typeinfo
*typei
, adns_rrtype type
);
539 /* Default function for the `getrrsz' type hook; returns the `fixed_rrsz'
540 * value from the typeinfo entry.
543 void adns__isort(void *array
, int nobjs
, int sz
, void *tempbuf
,
544 int (*needswap
)(void *context
, const void *a
, const void *b
),
546 /* Does an insertion sort of array which must contain nobjs objects
547 * each sz bytes long. tempbuf must point to a buffer at least
548 * sz bytes long. needswap should return !0 if a>b (strictly, ie
549 * wrong order) 0 if a<=b (ie, order is fine).
552 void adns__sigpipe_protect(adns_state
);
553 void adns__sigpipe_unprotect(adns_state
);
554 /* If SIGPIPE protection is not disabled, will block all signals except
555 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
556 * Each call to _protect must be followed by a call to _unprotect before
557 * any significant amount of code gets to run, since the old signal mask
558 * is stored in the adns structure.
561 /* From transmit.c: */
563 adns_status
adns__mkquery(adns_state ads
, vbuf
*vb
, int *id_r
,
564 const char *owner
, int ol
,
565 const typeinfo
*typei
, adns_rrtype type
,
566 adns_queryflags flags
);
567 /* Assembles a query packet in vb. A new id is allocated and returned.
570 adns_status
adns__mkquery_frdgram(adns_state ads
, vbuf
*vb
, int *id_r
,
571 const byte
*qd_dgram
, int qd_dglen
,
573 adns_rrtype type
, adns_queryflags flags
);
574 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
575 * That domain must be correct and untruncated.
578 void adns__querysend_tcp(adns_query qu
, struct timeval now
);
579 /* Query must be in state tcpw/tcpw; it will be sent if possible and
580 * no further processing can be done on it for now. The connection
581 * might be broken, but no reconnect will be attempted.
584 struct udpsocket
*adns__udpsocket_by_af(adns_state ads
, int af
);
585 /* Find the UDP socket structure in ads which has the given address family.
586 * Return null if there isn't one.
588 * This is used during initialization, so ads is only partially filled in.
589 * The requirements are that nudp is set, and that udpsocket[i].af are
590 * defined for 0<=i<nudp.
593 void adns__query_send(adns_query qu
, struct timeval now
);
594 /* Query must be in state tosend/NONE; it will be moved to a new state,
595 * and no further processing can be done on it for now.
596 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
597 * connected), tcpsent/timew, child/childw or done/output.)
598 * __query_send may decide to use either UDP or TCP depending whether
599 * _qf_usevc is set (or has become set) and whether the query is too
605 adns_status
adns__internal_submit(adns_state ads
, adns_query
*query_r
,
607 const typeinfo
*typei
, adns_rrtype type
,
608 vbuf
*qumsg_vb
, int id
,
609 adns_queryflags flags
, struct timeval now
,
611 /* Submits a query (for internal use, called during external submits).
613 * The new query is returned in *query_r, or we return adns_s_nomemory.
615 * The query datagram should already have been assembled in qumsg_vb;
616 * the memory for it is _taken over_ by this routine whether it
617 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
619 * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo
620 * field may be modified by type hooks.
622 * When the child query is done, ctx->callback will be called. The
623 * child will already have been taken off both the global list of
624 * queries in ads and the list of children in the parent. The child
625 * will be freed when the callback returns. The parent will have been
626 * taken off the global childw queue.
628 * The callback should either call adns__query_done, if it is
629 * complete, or adns__query_fail, if an error has occurred, in which
630 * case the other children (if any) will be cancelled. If the parent
631 * has more unfinished children (or has just submitted more) then the
632 * callback may choose to wait for them - it must then put the parent
633 * back on the childw queue.
636 void adns__search_next(adns_state ads
, adns_query qu
, struct timeval now
);
637 /* Walks down the searchlist for a query with adns_qf_search.
638 * The query should have just had a negative response, or not had
639 * any queries sent yet, and should not be on any queue.
640 * The query_dgram if any will be freed and forgotten and a new
641 * one constructed from the search_* members of the query.
643 * Cannot fail (in case of error, calls adns__query_fail).
646 void *adns__alloc_interim(adns_query qu
, size_t sz
);
647 void *adns__alloc_preserved(adns_query qu
, size_t sz
);
648 /* Allocates some memory, and records which query it came from
649 * and how much there was.
651 * If an error occurs in the query, all the memory from _interim is
652 * simply freed. If the query succeeds, one large buffer will be made
653 * which is big enough for all these allocations, and then
654 * adns__alloc_final will get memory from this buffer.
656 * _alloc_interim can fail (and return 0).
657 * The caller must ensure that the query is failed.
659 * The memory from _preserved is is kept and transferred into the
660 * larger buffer - unless we run out of memory, in which case it too
661 * is freed. When you use _preserved you have to add code to the
662 * x_nomem error exit case in adns__makefinal_query to clear out the
663 * pointers you made to those allocations, because that's when they're
664 * thrown away; you should also make a note in the declaration of
665 * those pointer variables, to note that they are _preserved rather
666 * than _interim. If they're in the answer, note it here:
667 * answer->cname and answer->owner are _preserved.
670 void adns__transfer_interim(adns_query from
, adns_query to
, void *block
);
671 /* Transfers an interim allocation from one query to another, so that
672 * the `to' query will have room for the data when we get to makefinal
673 * and so that the free will happen when the `to' query is freed
674 * rather than the `from' query.
676 * It is legal to call adns__transfer_interim with a null pointer; this
679 * _transfer_interim also ensures that the expiry time of the `to' query
680 * is no later than that of the `from' query, so that child queries'
681 * TTLs get inherited by their parents.
684 void adns__free_interim(adns_query qu
, void *p
);
685 /* Forget about a block allocated by adns__alloc_interim.
688 void *adns__alloc_mine(adns_query qu
, size_t sz
);
689 /* Like _interim, but does not record the length for later
690 * copying into the answer. This just ensures that the memory
691 * will be freed when we're done with the query.
694 void *adns__alloc_final(adns_query qu
, size_t sz
);
695 /* Cannot fail, and cannot return 0.
698 void adns__makefinal_block(adns_query qu
, void **blpp
, size_t sz
);
699 void adns__makefinal_str(adns_query qu
, char **strp
);
701 void adns__reset_preserved(adns_query qu
);
702 /* Resets all of the memory management stuff etc. to take account of
703 * only the _preserved stuff from _alloc_preserved. Used when we find
704 * an error somewhere and want to just report the error (with perhaps
705 * CNAME, owner, etc. info), and also when we're halfway through RRs
706 * in a datagram and discover that we need to retry the query.
709 void adns__cancel(adns_query qu
);
710 void adns__query_done(adns_query qu
);
711 void adns__query_fail(adns_query qu
, adns_status st
);
712 void adns__cancel_children(adns_query qu
);
714 void adns__returning(adns_state ads
, adns_query qu
);
715 /* Must be called before returning from adns any time that we have
716 * progressed (including made, finished or destroyed) queries.
718 * Might reenter adns via internal query callbacks, so
719 * external-faciing functions which call adns__returning should
720 * normally be avoided in internal code. */
724 void adns__procdgram(adns_state ads
, const byte
*dgram
, int len
,
725 int serv
, int viatcp
, struct timeval now
);
726 /* This function is allowed to cause new datagrams to be constructed
727 * and sent, or even new queries to be started. However,
728 * query-sending functions are not allowed to call any general event
729 * loop functions in case they accidentally call this.
731 * Ie, receiving functions may call sending functions.
732 * Sending functions may NOT call receiving functions.
737 const typeinfo
*adns__findtype(adns_rrtype type
);
746 int dglen
, max
, cbyte
, namelen
;
750 void adns__findlabel_start(findlabel_state
*fls
, adns_state ads
,
751 int serv
, adns_query qu
,
752 const byte
*dgram
, int dglen
, int max
,
753 int dmbegin
, int *dmend_rlater
);
754 /* Finds labels in a domain in a datagram.
756 * Call this routine first.
757 * dmend_rlater may be null. ads (and of course fls) may not be.
758 * serv may be -1, qu may be null - they are for error reporting.
761 adns_status
adns__findlabel_next(findlabel_state
*fls
,
762 int *lablen_r
, int *labstart_r
);
763 /* Then, call this one repeatedly.
765 * It will return adns_s_ok if all is well, and tell you the length
766 * and start of successive labels. labstart_r may be null, but
767 * lablen_r must not be.
769 * After the last label, it will return with *lablen_r zero.
770 * Do not then call it again; instead, just throw away the findlabel_state.
772 * *dmend_rlater will have been set to point to the next part of
773 * the datagram after the label (or after the uncompressed part,
774 * if compression was used). *namelen_rlater will have been set
775 * to the length of the domain name (total length of labels plus
776 * 1 for each intervening dot).
778 * If the datagram appears to be truncated, *lablen_r will be -1.
779 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
780 * Do not call _next again.
782 * There may also be errors, in which case *dmend_rlater,
783 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
784 * Do not then call findlabel_next again.
791 adns_status
adns__parse_domain(adns_state ads
, int serv
, adns_query qu
,
792 vbuf
*vb
, parsedomain_flags flags
,
793 const byte
*dgram
, int dglen
, int *cbyte_io
,
795 /* vb must already have been initialised; it will be reset if necessary.
796 * If there is truncation, vb->used will be set to 0; otherwise
797 * (if there is no error) vb will be null-terminated.
798 * If there is an error vb and *cbyte_io may be left indeterminate.
800 * serv may be -1 and qu may be 0 - they are used for error reporting only.
803 adns_status
adns__parse_domain_more(findlabel_state
*fls
, adns_state ads
,
804 adns_query qu
, vbuf
*vb
,
805 parsedomain_flags flags
,
807 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
808 * for continuing an existing domain or some such of some kind. Also, unlike
809 * _parse_domain, the domain data will be appended to vb, rather than replacing
810 * the existing contents.
813 adns_status
adns__findrr(adns_query qu
, int serv
,
814 const byte
*dgram
, int dglen
, int *cbyte_io
,
815 int *type_r
, int *class_r
, unsigned long *ttl_r
,
816 int *rdlen_r
, int *rdstart_r
,
817 int *ownermatchedquery_r
);
818 /* Finds the extent and some of the contents of an RR in a datagram
819 * and does some checks. The datagram is *dgram, length dglen, and
820 * the RR starts at *cbyte_io (which is updated afterwards to point
821 * to the end of the RR).
823 * The type, class, TTL and RRdata length and start are returned iff
824 * the corresponding pointer variables are not null. type_r, class_r
825 * and ttl_r may not be null. The TTL will be capped.
827 * If ownermatchedquery_r != 0 then the owner domain of this
828 * RR will be compared with that in the query (or, if the query
829 * has gone to a CNAME lookup, with the canonical name).
830 * In this case, *ownermatchedquery_r will be set to 0 or 1.
831 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
833 * If there is truncation then *type_r will be set to -1 and
834 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
837 * qu must obviously be non-null.
839 * If an error is returned then *type_r will be undefined too.
842 adns_status
adns__findrr_anychk(adns_query qu
, int serv
,
843 const byte
*dgram
, int dglen
, int *cbyte_io
,
844 int *type_r
, int *class_r
,
845 unsigned long *ttl_r
,
846 int *rdlen_r
, int *rdstart_r
,
847 const byte
*eo_dgram
, int eo_dglen
,
848 int eo_cbyte
, int *eo_matched_r
);
849 /* Like adns__findrr_checked, except that the datagram and
850 * owner to compare with can be specified explicitly.
852 * If the caller thinks they know what the owner of the RR ought to
853 * be they can pass in details in eo_*: this is another (or perhaps
854 * the same datagram), and a pointer to where the putative owner
855 * starts in that datagram. In this case *eo_matched_r will be set
856 * to 1 if the datagram matched or 0 if it did not. Either
857 * both eo_dgram and eo_matched_r must both be non-null, or they
858 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
859 * The eo datagram and contained owner domain MUST be valid and
863 void adns__update_expires(adns_query qu
, unsigned long ttl
,
865 /* Updates the `expires' field in the query, so that it doesn't exceed
869 bool adns__labels_equal(const byte
*a
, int al
, const byte
*b
, int bl
);
873 void adns__tcp_broken(adns_state ads
, const char *what
, const char *why
);
874 /* what and why may be both 0, or both non-0. */
876 void adns__tcp_tryconnect(adns_state ads
, struct timeval now
);
878 void adns__autosys(adns_state ads
, struct timeval now
);
879 /* Make all the system calls we want to if the application wants us to.
880 * Must not be called from within adns internal processing functions,
881 * lest we end up in recursive descent !
884 void adns__must_gettimeofday(adns_state ads
, const struct timeval
**now_io
,
885 struct timeval
*tv_buf
);
886 /* Call with care - might reentrantly cause queries to be completed! */
888 int adns__pollfds(adns_state ads
, struct pollfd pollfds_buf
[MAX_POLLFDS
]);
889 void adns__fdevents(adns_state ads
,
890 const struct pollfd
*pollfds
, int npollfds
,
891 int maxfd
, const fd_set
*readfds
,
892 const fd_set
*writefds
, const fd_set
*exceptfds
,
893 struct timeval now
, int *r_r
);
894 int adns__internal_check(adns_state ads
,
895 adns_query
*query_io
,
896 adns_answer
**answer
,
899 void adns__timeouts(adns_state ads
, int act
,
900 struct timeval
**tv_io
, struct timeval
*tvbuf
,
902 /* If act is !0, then this will also deal with the TCP connection
903 * if previous events broke it or require it to be connected.
908 void adns__consistency(adns_state ads
, adns_query qu
, consistency_checks cc
);
910 /* Useful static inline functions: */
912 static inline int ctype_whitespace(int c
) {
913 return c
==' ' || c
=='\n' || c
=='\t';
915 static inline int ctype_digit(int c
) { return c
>='0' && c
<='9'; }
916 static inline int ctype_alpha(int c
) {
917 return (c
>= 'a' && c
<= 'z') || (c
>= 'A' && c
<= 'Z');
919 static inline int ctype_toupper(int c
) {
920 return ctype_alpha(c
) ?
(c
& ~32) : c
;
922 static inline int ctype_822special(int c
) {
923 return strchr("()<>@,;:\\\".[]",c
) != 0;
925 static inline int ctype_domainunquoted(int c
) {
926 return ctype_alpha(c
) || ctype_digit(c
) || (strchr("-_/+",c
) != 0);
929 static inline int errno_resources(int e
) { return e
==ENOMEM
|| e
==ENOBUFS
; }
933 #define MEM_ROUND(sz) \
934 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
935 * sizeof(union maxalign) )
937 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
938 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
939 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
940 #define GET_L(cb,tv) ( (tv)=0, \
941 (tv)|=(GETIL_B((cb))<<24), \
942 (tv)|=(GETIL_B((cb))<<16), \
943 (tv)|=(GETIL_B((cb))<<8), \