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 Ian Jackson
10 * Copyright (C) 1999-2000,2003,2006 Tony Finch
11 * Copyright (C) 1991 Massachusetts Institute of Technology
12 * (See the file INSTALL for full details.)
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 #ifndef ADNS_INTERNAL_H_INCLUDED
30 #define ADNS_INTERNAL_H_INCLUDED
33 typedef unsigned char byte
;
48 #ifdef ADNS_REGRESS_TEST
49 # include "hredirect.h"
52 /* Configuration and constants */
55 #define MAXSORTLIST 15
56 #define UDPMAXRETRIES 15
57 #define UDPRETRYMS 2000
58 #define TCPWAITMS 30000
59 #define TCPCONNMS 14000
60 #define TCPIDLEMS 30000
61 #define MAXTTLBELIEVE (7*86400) /* any TTL > 7 days is capped */
64 #define DNS_MAXUDP 512
65 #define DNS_MAXLABEL 63
66 #define DNS_MAXDOMAIN 255
67 #define DNS_HDRSIZE 12
68 #define DNS_IDOFFSET 0
69 #define DNS_CLASS_IN 1
71 #define DNS_INADDR_ARPA "in-addr", "arpa"
72 #define DNS_IP6_ARPA "ip6", "arpa"
74 #define MAX_POLLFDS ADNS_POLLFDS_RECOMMENDED
76 /* Some preprocessor hackery */
78 #define GLUE(x, y) GLUE_(x, y)
79 #define GLUE_(x, y) x##y
81 /* C99 macro `...' must match at least one argument, so the naive definition
82 * `#define CAR(car, ...) car' won't work. But it's easy to arrange for the
83 * tail to be nonempty if we're just going to discard it anyway. */
84 #define CAR(...) CAR_(__VA_ARGS__, _)
85 #define CAR_(car, ...) car
87 /* Extracting the tail of an argument list is rather more difficult. The
88 * following trick is based on one by Laurent Deniau to count the number of
89 * arguments to a macro, simplified in two ways: (a) it only handles up to
90 * eight arguments, and (b) it only needs to distinguish the one-argument
91 * case from many arguments. */
92 #define CDR(...) CDR_(__VA_ARGS__, m, m, m, m, m, m, m, 1, _)(__VA_ARGS__)
93 #define CDR_(_1, _2, _3, _4, _5, _6, _7, _8, n, ...) CDR_##n
95 #define CDR_m(_, ...) __VA_ARGS__
101 } consistency_checks
;
112 /* Shared data structures */
124 int dglen
, nsstart
, nscount
, arcount
;
133 struct af_addr
{ int af
; union gen_addr addr
; };
135 #define NREVDOMAINS 2 /* keep in sync with addrfam! */
136 struct revparse_state
{
137 unsigned map
; /* which domains are still live */
138 byte ipv
[NREVDOMAINS
][32]; /* address components so far */
141 union checklabel_state
{
142 struct revparse_state ptr
;
147 void (*callback
)(adns_query parent
, adns_query child
);
151 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 *label
, int lablen
);
200 /* Check a label from the query domain string. The label is not
201 * necessarily null-terminated. The hook can refuse the query's submission
202 * by returning a nonzero status. State can be stored in *cls between
203 * calls, and useful information can be stashed in ctx->tinfo, to be stored
204 * with the query (e.g., it will be available to the parse hook). This
205 * hook can detect a first call because labnum is zero, and a final call
206 * because lablen is zero.
209 void (*postsort
)(adns_state ads
, void *array
, int nrrs
,int rrsz
,
210 const struct typeinfo
*typei
);
211 /* Called immediately after the RRs have been sorted, and may rearrange
212 * them. (This is really for the benefit of SRV's bizarre weighting
213 * stuff.) May be 0 to mean nothing needs to be done.
216 int (*getrrsz
)(const struct typeinfo
*typei
, adns_rrtype type
);
217 /* Return the output resource-record element size; if this is null, then
218 * the rrsz member can be used.
222 adns_status
adns__ckl_hostname(adns_state ads
, adns_queryflags flags
,
223 union checklabel_state
*cls
,
224 qcontext
*ctx
, int labnum
,
225 const char *label
, int lablen
);
226 /* implemented in query.c, used by types.c as default
227 * and as part of implementation for some fancier types
228 * doesn't require any state */
230 typedef struct allocnode
{
231 struct allocnode
*next
, *back
;
245 enum { query_tosend
, query_tcpw
, query_childw
, query_done
} state
;
246 adns_query back
, next
, parent
;
247 struct { adns_query head
, tail
; } children
;
248 struct { adns_query back
, next
; } siblings
;
249 struct { allocnode
*head
, *tail
; } allocations
;
250 int interim_allocd
, preserved_allocd
;
251 void *final_allocspace
;
253 const typeinfo
*typei
;
258 /* General-purpose messing-about buffer.
259 * Wherever a `big' interface is crossed, this may be corrupted/changed
260 * unless otherwise specified.
264 /* This is allocated when a query is submitted, to avoid being unable
265 * to relate errors to queries if we run out of memory. During
266 * query processing status, rrs is 0. cname is set if
267 * we found a cname (this corresponds to cname_dgram in the query
268 * structure). type is set from the word go. nrrs and rrs
269 * are set together, when we find how many rrs there are.
270 * owner is set during querying unless we're doing searchlist,
271 * in which case it is set only when we find an answer.
275 int cname_dglen
, cname_begin
;
276 /* If non-0, has been allocated using . */
279 int search_origlen
, search_pos
, search_doneabs
;
280 /* Used by the searching algorithm. The query domain in textual form
281 * is copied into the vbuf, and _origlen set to its length. Then
282 * we walk the searchlist, if we want to. _pos says where we are
283 * (next entry to try), and _doneabs says whether we've done the
284 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
285 * but not done yet). If flags doesn't have adns_qf_search then
286 * the vbuf is initialised but empty and everything else is zero.
289 int id
, flags
, retries
;
291 unsigned long udpsent
; /* bitmap indexed by server */
292 struct timeval timeout
;
293 time_t expires
; /* Earliest expiry time of any record we used. */
299 * state Queue child id nextudpserver udpsent tcpfailed
301 * tosend NONE null >=0 0 zero zero
302 * tosend udpw null >=0 any nonzero zero
303 * tosend NONE null >=0 any nonzero zero
305 * tcpw tcpw null >=0 irrelevant any any
307 * child childw set >=0 irrelevant irrelevant irrelevant
308 * child NONE null >=0 irrelevant irrelevant irrelevant
309 * done output null -1 irrelevant irrelevant irrelevant
311 * Queries are only not on a queue when they are actually being processed.
312 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
313 * iff the tcp connection is in state server_ok.
315 * +------------------------+
316 * START -----> | tosend/NONE |
317 * +------------------------+
319 * too big for UDP / UDP timeout \ \ send via UDP
320 * send via TCP / more retries \ \
321 * when conn'd / desired \ \
324 * +-----------+ +-------------+
325 * | tcpw/tcpw | ________ | tosend/udpw |
326 * +-----------+ \ +-------------+
327 * | | | UDP timeout | |
330 * \ | TCP died | desired | |
332 * \ \ servers | TCP / |
333 * \ \ to try | timeout / |
335 * reply \ _| +------------------+ / reply
336 * \ | done/output FAIL | /
337 * \ +------------------+ /
340 * (..... got reply ....)
342 * need child query/ies / \ no child query
345 * +---------------+ +----------------+
346 * | childw/childw | ----------------> | done/output OK |
347 * +---------------+ children done +----------------+
351 struct query_queue
{ adns_query head
, tail
; };
356 adns_initflags iflags
;
357 adns_logcallbackfn
*logfn
;
360 struct query_queue udpw
, tcpw
, childw
, output
;
361 adns_query forallnext
;
362 int nextid
, tcpsocket
;
363 struct udpsocket
{ int af
; int fd
; } udpsocket
[MAXUDP
];
365 vbuf tcpsend
, tcprecv
;
366 int nservers
, nsortlist
, nsearchlist
, searchndots
, tcpserver
, tcprecv_skip
;
367 enum adns__tcpstate
{
368 server_disconnected
, server_connecting
,
369 server_ok
, server_broken
371 struct timeval tcptimeout
;
372 /* This will have tv_sec==0 if it is not valid. It will always be
373 * valid if tcpstate _connecting. When _ok, it will be nonzero if
374 * we are idle (ie, tcpw queue is empty), in which case it is the
375 * absolute time when we will close the connection.
377 struct sigaction stdsigpipe
;
379 struct pollfd pollfds_buf
[MAX_POLLFDS
];
380 adns_rr_addr servers
[MAXSERVERS
];
383 union gen_addr base
, mask
;
384 } sortlist
[MAXSORTLIST
];
386 unsigned short rand48xsubi
[3];
389 /* From addrfam.c: */
391 extern int adns__af_supported_p(int af
);
392 /* Return nonzero if the address family af known to the library and supported
393 * by the other addrfam operations. Note that the other operations will
394 * abort on an unrecognized address family rather than returning an error
398 extern int adns__genaddr_equal_p(int af
, const union gen_addr
*a
,
399 int bf
, const void *b
);
400 /* b should point to a `struct in_addr' or equivalent for the address family
401 * bf. Returns nonzero if the two addresses are equal.
404 extern int adns__sockaddr_equal_p(const struct sockaddr
*sa
,
405 const struct sockaddr
*sb
);
406 /* Return nonzero if the two socket addresses are equal (in all significant
410 extern int adns__addr_width(int af
);
411 /* Return the width of addresses of family af, in bits. */
413 extern void adns__prefix_mask(int af
, int len
, union gen_addr
*mask_r
);
414 /* Store in mask_r an address mask for address family af, whose first len
415 * bits are set and the remainder are clear. This is what you want for
416 * converting a prefix length into a netmask.
419 extern int adns__guess_prefix_length(int af
, const union gen_addr
*addr
);
420 /* Given a network base address, guess the appropriate prefix length based on
421 * the appropriate rules for the address family (e.g., for IPv4, this uses
422 * the old address classes).
425 extern int adns__addr_match_p(int addraf
, const union gen_addr
*addr
,
426 int netaf
, const union gen_addr
*base
,
427 const union gen_addr
*mask
);
428 /* Given an address af (with family addraf) and a network (with family netaf,
429 * base address base, and netmask mask), return nonzero if the address lies
430 * within the network.
433 extern void adns__sockaddr_extract(const struct sockaddr
*sa
,
434 union gen_addr
*a_r
, int *port_r
);
435 /* Extract fields from the socket address, filling in *a_r and *port_r with
436 * the address and (integer, host byte-order) port number, respectively.
437 * Either (or, pointlessly, both) of a_r and port_r may be null to mean
441 extern void adns__sockaddr_inject(const union gen_addr
*a
, int port
,
442 struct sockaddr
*sa
);
443 /* Inject fields into the socket adress sa. If a is not null, copy the
444 * address in; if port is not -1, then copy the port (converting from host
445 * byte-order). Assumes that sa->sa_family is already set correctly.
448 char *adns__sockaddr_ntoa(const struct sockaddr
*sa
, char *buf
);
449 /* Convert sa to a string, and write it to buf, which must be at least
450 * ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Return buf; can't fail.
453 extern int adns__make_reverse_domain(const struct sockaddr
*sa
,
455 char **buf_io
, size_t bufsz
,
457 /* Construct a reverse domain string, given a socket address and a parent
458 * zone. If zone is null, then use the standard reverse-lookup zone for the
459 * address family. If the length of the resulting string is no larger than
460 * bufsz, then the result is stored starting at *buf_io; otherwise a new
461 * buffer is allocated is used, and a pointer to it is stored in both *buf_io
462 * and *buf_free_r (the latter of which should be null on entry). If
463 * something goes wrong, then an errno value is returned: ENOSYS if the
464 * address family of sa isn't recognized, or ENOMEM if the attempt to
465 * allocate an output buffer failed.
468 extern int adns__revparse_label(struct revparse_state
*rps
, int labnum
,
469 const char *label
, int lablen
);
470 /* Parse a label in a reverse-domain name, given its index labnum (starting
471 * from zero), a pointer to its contents (which need not be null-terminated),
472 * and its length. The state in *rps is initialized implicitly when labnum
475 * Returns zero if the parse was successful, nonzero if the domain name is
476 * definitely invalid and the parse must be abandoned.
479 extern int adns__revparse_done(struct revparse_state
*rps
, int nlabels
,
480 adns_rrtype
*rrtype_r
, struct af_addr
*addr_r
);
481 /* Finishes parsing a reverse-domain name, given the total number of labels
482 * in the name. On success, fills in the address in *addr_r, and the forward
483 * query type in *rrtype_r (because that turns out to be useful). Returns
484 * nonzero if the parse must be abandoned.
489 int adns__setnonblock(adns_state ads
, int fd
); /* => errno value */
491 /* From general.c: */
493 void adns__vlprintf(adns_state ads
, const char *fmt
, va_list al
);
494 void adns__lprintf(adns_state ads
, const char *fmt
,
495 ...) PRINTFFORMAT(2,3);
497 void adns__vdiag(adns_state ads
, const char *pfx
, adns_initflags prevent
,
498 int serv
, adns_query qu
, const char *fmt
, va_list al
);
500 void adns__debug(adns_state ads
, int serv
, adns_query qu
,
501 const char *fmt
, ...) PRINTFFORMAT(4,5);
502 void adns__warn(adns_state ads
, int serv
, adns_query qu
,
503 const char *fmt
, ...) PRINTFFORMAT(4,5);
504 void adns__diag(adns_state ads
, int serv
, adns_query qu
,
505 const char *fmt
, ...) PRINTFFORMAT(4,5);
507 int adns__vbuf_ensure(vbuf
*vb
, int want
);
508 int adns__vbuf_appendstr(vbuf
*vb
, const char *data
); /* doesn't include nul */
509 int adns__vbuf_append(vbuf
*vb
, const byte
*data
, int len
);
510 /* 1=>success, 0=>realloc failed */
511 void adns__vbuf_appendq(vbuf
*vb
, const byte
*data
, int len
);
512 void adns__vbuf_init(vbuf
*vb
);
513 void adns__vbuf_free(vbuf
*vb
);
515 const char *adns__diag_domain(adns_state ads
, int serv
, adns_query qu
,
517 const byte
*dgram
, int dglen
, int cbyte
);
518 /* Unpicks a domain in a datagram and returns a string suitable for
519 * printing it as. Never fails - if an error occurs, it will
520 * return some kind of string describing the error.
522 * serv may be -1 and qu may be 0. vb must have been initialised,
523 * and will be left in an arbitrary consistent state.
525 * Returns either vb->buf, or a pointer to a string literal. Do not modify
526 * vb before using the return value.
529 int adns__getrrsz_default(const typeinfo
*typei
, adns_rrtype type
);
530 /* Default function for the `getrrsz' type hook; returns the `fixed_rrsz'
531 * value from the typeinfo entry.
534 void adns__isort(void *array
, int nobjs
, int sz
, void *tempbuf
,
535 int (*needswap
)(void *context
, const void *a
, const void *b
),
537 /* Does an insertion sort of array which must contain nobjs objects
538 * each sz bytes long. tempbuf must point to a buffer at least
539 * sz bytes long. needswap should return !0 if a>b (strictly, ie
540 * wrong order) 0 if a<=b (ie, order is fine).
543 void adns__sigpipe_protect(adns_state
);
544 void adns__sigpipe_unprotect(adns_state
);
545 /* If SIGPIPE protection is not disabled, will block all signals except
546 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
547 * Each call to _protect must be followed by a call to _unprotect before
548 * any significant amount of code gets to run, since the old signal mask
549 * is stored in the adns structure.
552 /* From transmit.c: */
554 adns_status
adns__mkquery(adns_state ads
, vbuf
*vb
, int *id_r
,
555 const char *owner
, int ol
,
556 const typeinfo
*typei
, adns_rrtype type
,
557 adns_queryflags flags
);
558 /* Assembles a query packet in vb. A new id is allocated and returned.
561 adns_status
adns__mkquery_frdgram(adns_state ads
, vbuf
*vb
, int *id_r
,
562 const byte
*qd_dgram
, int qd_dglen
,
564 adns_rrtype type
, adns_queryflags flags
);
565 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
566 * That domain must be correct and untruncated.
569 void adns__querysend_tcp(adns_query qu
, struct timeval now
);
570 /* Query must be in state tcpw/tcpw; it will be sent if possible and
571 * no further processing can be done on it for now. The connection
572 * might be broken, but no reconnect will be attempted.
575 struct udpsocket
*adns__udpsocket_by_af(adns_state ads
, int af
);
576 /* Find the UDP socket structure in ads which has the given address family.
577 * Return null if there isn't one.
579 * This is used during initialization, so ads is only partially filled in.
580 * The requirements are that nudp is set, and that udpsocket[i].af are
581 * defined for 0<=i<nudp.
584 void adns__query_send(adns_query qu
, struct timeval now
);
585 /* Query must be in state tosend/NONE; it will be moved to a new state,
586 * and no further processing can be done on it for now.
587 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
588 * connected), tcpsent/timew, child/childw or done/output.)
589 * __query_send may decide to use either UDP or TCP depending whether
590 * _qf_usevc is set (or has become set) and whether the query is too
596 adns_status
adns__internal_submit(adns_state ads
, adns_query
*query_r
,
597 const typeinfo
*typei
, adns_rrtype type
,
598 vbuf
*qumsg_vb
, int id
,
599 adns_queryflags flags
, struct timeval now
,
601 /* Submits a query (for internal use, called during external submits).
603 * The new query is returned in *query_r, or we return adns_s_nomemory.
605 * The query datagram should already have been assembled in qumsg_vb;
606 * the memory for it is _taken over_ by this routine whether it
607 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
609 * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo
610 * field may be modified by type hooks.
612 * When the child query is done, ctx->callback will be called. The
613 * child will already have been taken off both the global list of
614 * queries in ads and the list of children in the parent. The child
615 * will be freed when the callback returns. The parent will have been
616 * taken off the global childw queue.
618 * The callback should either call adns__query_done, if it is
619 * complete, or adns__query_fail, if an error has occurred, in which
620 * case the other children (if any) will be cancelled. If the parent
621 * has more unfinished children (or has just submitted more) then the
622 * callback may choose to wait for them - it must then put the parent
623 * back on the childw queue.
626 void adns__search_next(adns_state ads
, adns_query qu
, struct timeval now
);
627 /* Walks down the searchlist for a query with adns_qf_search.
628 * The query should have just had a negative response, or not had
629 * any queries sent yet, and should not be on any queue.
630 * The query_dgram if any will be freed and forgotten and a new
631 * one constructed from the search_* members of the query.
633 * Cannot fail (in case of error, calls adns__query_fail).
636 void *adns__alloc_interim(adns_query qu
, size_t sz
);
637 void *adns__alloc_preserved(adns_query qu
, size_t sz
);
638 /* Allocates some memory, and records which query it came from
639 * and how much there was.
641 * If an error occurs in the query, all the memory from _interim is
642 * simply freed. If the query succeeds, one large buffer will be made
643 * which is big enough for all these allocations, and then
644 * adns__alloc_final will get memory from this buffer.
646 * _alloc_interim can fail (and return 0).
647 * The caller must ensure that the query is failed.
649 * The memory from _preserved is is kept and transferred into the
650 * larger buffer - unless we run out of memory, in which case it too
651 * is freed. When you use _preserved you have to add code to the
652 * x_nomem error exit case in adns__makefinal_query to clear out the
653 * pointers you made to those allocations, because that's when they're
654 * thrown away; you should also make a note in the declaration of
655 * those pointer variables, to note that they are _preserved rather
656 * than _interim. If they're in the answer, note it here:
657 * answer->cname and answer->owner are _preserved.
660 void adns__transfer_interim(adns_query from
, adns_query to
,
661 void *block
, size_t sz
);
662 /* Transfers an interim allocation from one query to another, so that
663 * the `to' query will have room for the data when we get to makefinal
664 * and so that the free will happen when the `to' query is freed
665 * rather than the `from' query.
667 * It is legal to call adns__transfer_interim with a null pointer; this
670 * _transfer_interim also ensures that the expiry time of the `to' query
671 * is no later than that of the `from' query, so that child queries'
672 * TTLs get inherited by their parents.
675 void *adns__alloc_mine(adns_query qu
, size_t sz
);
676 /* Like _interim, but does not record the length for later
677 * copying into the answer. This just ensures that the memory
678 * will be freed when we're done with the query.
681 void *adns__alloc_final(adns_query qu
, size_t sz
);
682 /* Cannot fail, and cannot return 0.
685 void adns__makefinal_block(adns_query qu
, void **blpp
, size_t sz
);
686 void adns__makefinal_str(adns_query qu
, char **strp
);
688 void adns__reset_preserved(adns_query qu
);
689 /* Resets all of the memory management stuff etc. to take account of
690 * only the _preserved stuff from _alloc_preserved. Used when we find
691 * an error somewhere and want to just report the error (with perhaps
692 * CNAME, owner, etc. info), and also when we're halfway through RRs
693 * in a datagram and discover that we need to retry the query.
696 void adns__query_done(adns_query qu
);
697 void adns__query_fail(adns_query qu
, adns_status stat
);
701 void adns__procdgram(adns_state ads
, const byte
*dgram
, int len
,
702 int serv
, int viatcp
, struct timeval now
);
703 /* This function is allowed to cause new datagrams to be constructed
704 * and sent, or even new queries to be started. However,
705 * query-sending functions are not allowed to call any general event
706 * loop functions in case they accidentally call this.
708 * Ie, receiving functions may call sending functions.
709 * Sending functions may NOT call receiving functions.
714 const typeinfo
*adns__findtype(adns_rrtype type
);
723 int dglen
, max
, cbyte
, namelen
;
727 void adns__findlabel_start(findlabel_state
*fls
, adns_state ads
,
728 int serv
, adns_query qu
,
729 const byte
*dgram
, int dglen
, int max
,
730 int dmbegin
, int *dmend_rlater
);
731 /* Finds labels in a domain in a datagram.
733 * Call this routine first.
734 * dmend_rlater may be null. ads (and of course fls) may not be.
735 * serv may be -1, qu may be null - they are for error reporting.
738 adns_status
adns__findlabel_next(findlabel_state
*fls
,
739 int *lablen_r
, int *labstart_r
);
740 /* Then, call this one repeatedly.
742 * It will return adns_s_ok if all is well, and tell you the length
743 * and start of successive labels. labstart_r may be null, but
744 * lablen_r must not be.
746 * After the last label, it will return with *lablen_r zero.
747 * Do not then call it again; instead, just throw away the findlabel_state.
749 * *dmend_rlater will have been set to point to the next part of
750 * the datagram after the label (or after the uncompressed part,
751 * if compression was used). *namelen_rlater will have been set
752 * to the length of the domain name (total length of labels plus
753 * 1 for each intervening dot).
755 * If the datagram appears to be truncated, *lablen_r will be -1.
756 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
757 * Do not call _next again.
759 * There may also be errors, in which case *dmend_rlater,
760 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
761 * Do not then call findlabel_next again.
768 adns_status
adns__parse_domain(adns_state ads
, int serv
, adns_query qu
,
769 vbuf
*vb
, parsedomain_flags flags
,
770 const byte
*dgram
, int dglen
, int *cbyte_io
,
772 /* vb must already have been initialised; it will be reset if necessary.
773 * If there is truncation, vb->used will be set to 0; otherwise
774 * (if there is no error) vb will be null-terminated.
775 * If there is an error vb and *cbyte_io may be left indeterminate.
777 * serv may be -1 and qu may be 0 - they are used for error reporting only.
780 adns_status
adns__parse_domain_more(findlabel_state
*fls
, adns_state ads
,
781 adns_query qu
, vbuf
*vb
,
782 parsedomain_flags flags
,
784 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
785 * for continuing an existing domain or some such of some kind. Also, unlike
786 * _parse_domain, the domain data will be appended to vb, rather than replacing
787 * the existing contents.
790 adns_status
adns__findrr(adns_query qu
, int serv
,
791 const byte
*dgram
, int dglen
, int *cbyte_io
,
792 int *type_r
, int *class_r
, unsigned long *ttl_r
,
793 int *rdlen_r
, int *rdstart_r
,
794 int *ownermatchedquery_r
);
795 /* Finds the extent and some of the contents of an RR in a datagram
796 * and does some checks. The datagram is *dgram, length dglen, and
797 * the RR starts at *cbyte_io (which is updated afterwards to point
798 * to the end of the RR).
800 * The type, class, TTL and RRdata length and start are returned iff
801 * the corresponding pointer variables are not null. type_r, class_r
802 * and ttl_r may not be null. The TTL will be capped.
804 * If ownermatchedquery_r != 0 then the owner domain of this
805 * RR will be compared with that in the query (or, if the query
806 * has gone to a CNAME lookup, with the canonical name).
807 * In this case, *ownermatchedquery_r will be set to 0 or 1.
808 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
810 * If there is truncation then *type_r will be set to -1 and
811 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
814 * qu must obviously be non-null.
816 * If an error is returned then *type_r will be undefined too.
819 adns_status
adns__findrr_anychk(adns_query qu
, int serv
,
820 const byte
*dgram
, int dglen
, int *cbyte_io
,
821 int *type_r
, int *class_r
,
822 unsigned long *ttl_r
,
823 int *rdlen_r
, int *rdstart_r
,
824 const byte
*eo_dgram
, int eo_dglen
,
825 int eo_cbyte
, int *eo_matched_r
);
826 /* Like adns__findrr_checked, except that the datagram and
827 * owner to compare with can be specified explicitly.
829 * If the caller thinks they know what the owner of the RR ought to
830 * be they can pass in details in eo_*: this is another (or perhaps
831 * the same datagram), and a pointer to where the putative owner
832 * starts in that datagram. In this case *eo_matched_r will be set
833 * to 1 if the datagram matched or 0 if it did not. Either
834 * both eo_dgram and eo_matched_r must both be non-null, or they
835 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
836 * The eo datagram and contained owner domain MUST be valid and
840 void adns__update_expires(adns_query qu
, unsigned long ttl
,
842 /* Updates the `expires' field in the query, so that it doesn't exceed
846 int vbuf__append_quoted1035(vbuf
*vb
, const byte
*buf
, int len
);
850 void adns__tcp_broken(adns_state ads
, const char *what
, const char *why
);
851 /* what and why may be both 0, or both non-0. */
853 void adns__tcp_tryconnect(adns_state ads
, struct timeval now
);
855 void adns__autosys(adns_state ads
, struct timeval now
);
856 /* Make all the system calls we want to if the application wants us to.
857 * Must not be called from within adns internal processing functions,
858 * lest we end up in recursive descent !
861 void adns__must_gettimeofday(adns_state ads
, const struct timeval
**now_io
,
862 struct timeval
*tv_buf
);
864 int adns__pollfds(adns_state ads
, struct pollfd pollfds_buf
[MAX_POLLFDS
]);
865 void adns__fdevents(adns_state ads
,
866 const struct pollfd
*pollfds
, int npollfds
,
867 int maxfd
, const fd_set
*readfds
,
868 const fd_set
*writefds
, const fd_set
*exceptfds
,
869 struct timeval now
, int *r_r
);
870 int adns__internal_check(adns_state ads
,
871 adns_query
*query_io
,
872 adns_answer
**answer
,
875 void adns__timeouts(adns_state ads
, int act
,
876 struct timeval
**tv_io
, struct timeval
*tvbuf
,
878 /* If act is !0, then this will also deal with the TCP connection
879 * if previous events broke it or require it to be connected.
884 void adns__consistency(adns_state ads
, adns_query qu
, consistency_checks cc
);
886 /* Useful static inline functions: */
888 static inline int ctype_whitespace(int c
) {
889 return c
==' ' || c
=='\n' || c
=='\t';
891 static inline int ctype_digit(int c
) { return c
>='0' && c
<='9'; }
892 static inline int ctype_alpha(int c
) {
893 return (c
>= 'a' && c
<= 'z') || (c
>= 'A' && c
<= 'Z');
895 static inline int ctype_822special(int c
) {
896 return strchr("()<>@,;:\\\".[]",c
) != 0;
898 static inline int ctype_domainunquoted(int c
) {
899 return ctype_alpha(c
) || ctype_digit(c
) || (strchr("-_/+",c
) != 0);
902 static inline int errno_resources(int e
) { return e
==ENOMEM
|| e
==ENOBUFS
; }
906 #define MEM_ROUND(sz) \
907 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
908 * sizeof(union maxalign) )
910 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
911 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
912 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
913 #define GET_L(cb,tv) ( (tv)=0, \
914 (tv)|=(GETIL_B((cb))<<24), \
915 (tv)|=(GETIL_B((cb))<<16), \
916 (tv)|=(GETIL_B((cb))<<8), \