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
;
113 adns__qf_addr_answer
= 0x01000000,/* addr query received an answer */
114 adns__qf_addr_cname
= 0x02000000 /* addr subquery performed on cname */
117 /* Shared data structures */
129 int dglen
, nsstart
, nscount
, arcount
;
138 struct af_addr
{ int af
; union gen_addr addr
; };
140 #define NREVDOMAINS 2 /* keep in sync with addrfam! */
141 struct revparse_state
{
142 unsigned map
; /* which domains are still live */
143 byte ipv
[NREVDOMAINS
][32]; /* address components so far */
146 union checklabel_state
{
147 struct revparse_state ptr
;
152 void (*callback
)(adns_query parent
, adns_query child
);
156 adns_rrtype rev_rrtype
;
162 } tinfo
; /* type-specific state for the query itself: zero-init if you
163 * don't know better. */
166 adns_rr_hostaddr
*hostaddr
;
167 } pinfo
; /* state for use by parent's callback function */
170 typedef struct typeinfo
{
176 void (*makefinal
)(adns_query qu
, void *data
);
177 /* Change memory management of *data.
178 * Previously, used alloc_interim, now use alloc_final.
181 adns_status (*convstring
)(vbuf
*vb
, const void *data
);
182 /* Converts the RR data to a string representation in vbuf.
183 * vbuf will be appended to (it must have been initialised),
184 * and will not be null-terminated by convstring.
187 adns_status (*parse
)(const parseinfo
*pai
, int cbyte
,
188 int max
, void *store_r
);
189 /* Parse one RR, in dgram of length dglen, starting at cbyte and
190 * extending until at most max.
192 * The RR should be stored at *store_r, of length qu->typei->getrrsz().
194 * If there is an overrun which might indicate truncation, it should set
195 * *rdstart to -1; otherwise it may set it to anything else positive.
197 * nsstart is the offset of the authority section.
200 int (*diff_needswap
)(adns_state ads
,const void *datap_a
,const void *datap_b
);
201 /* Returns !0 if RR a should be strictly after RR b in the sort order,
202 * 0 otherwise. Must not fail.
205 adns_status (*checklabel
)(adns_state ads
, adns_queryflags flags
,
206 union checklabel_state
*cls
, qcontext
*ctx
,
207 int labnum
, const char *label
, int lablen
);
208 /* Check a label from the query domain string. The label is not
209 * necessarily null-terminated. The hook can refuse the query's submission
210 * by returning a nonzero status. State can be stored in *cls between
211 * calls, and useful information can be stashed in ctx->tinfo, to be stored
212 * with the query (e.g., it will be available to the parse hook). This
213 * hook can detect a first call because labnum is zero, and a final call
214 * because lablen is zero.
217 void (*postsort
)(adns_state ads
, void *array
, int nrrs
,int rrsz
,
218 const struct typeinfo
*typei
);
219 /* Called immediately after the RRs have been sorted, and may rearrange
220 * them. (This is really for the benefit of SRV's bizarre weighting
221 * stuff.) May be 0 to mean nothing needs to be done.
224 int (*getrrsz
)(const struct typeinfo
*typei
, adns_rrtype type
);
225 /* Return the output resource-record element size; if this is null, then
226 * the rrsz member can be used.
229 void (*query_send
)(adns_query qu
, struct timeval now
);
230 /* Send the query to nameservers, and hook it into the appropriate queue.
231 * Normal behaviour is to call adns__query_send, but this can be overridden
232 * for special effects.
236 adns_status
adns__ckl_hostname(adns_state ads
, adns_queryflags flags
,
237 union checklabel_state
*cls
,
238 qcontext
*ctx
, int labnum
,
239 const char *label
, int lablen
);
240 /* implemented in query.c, used by types.c as default
241 * and as part of implementation for some fancier types
242 * doesn't require any state */
244 typedef struct allocnode
{
245 struct allocnode
*next
, *back
;
260 enum { query_tosend
, query_tcpw
, query_childw
, query_done
} state
;
261 adns_query back
, next
, parent
;
262 struct { adns_query head
, tail
; } children
;
263 struct { adns_query back
, next
; } siblings
;
264 struct { allocnode
*head
, *tail
; } allocations
;
265 int interim_allocd
, preserved_allocd
;
266 void *final_allocspace
;
268 const typeinfo
*typei
;
273 /* General-purpose messing-about buffer.
274 * Wherever a `big' interface is crossed, this may be corrupted/changed
275 * unless otherwise specified.
279 /* This is allocated when a query is submitted, to avoid being unable
280 * to relate errors to queries if we run out of memory. During
281 * query processing status, rrs is 0. cname is set if
282 * we found a cname (this corresponds to cname_dgram in the query
283 * structure). type is set from the word go. nrrs and rrs
284 * are set together, when we find how many rrs there are.
285 * owner is set during querying unless we're doing searchlist,
286 * in which case it is set only when we find an answer.
290 int cname_dglen
, cname_begin
;
291 /* If non-0, has been allocated using . */
294 int search_origlen
, search_pos
, search_doneabs
;
295 /* Used by the searching algorithm. The query domain in textual form
296 * is copied into the vbuf, and _origlen set to its length. Then
297 * we walk the searchlist, if we want to. _pos says where we are
298 * (next entry to try), and _doneabs says whether we've done the
299 * absolute query yet (0=not yet, 1=done, -1=must do straight away,
300 * but not done yet). If flags doesn't have adns_qf_search then
301 * the vbuf is initialised but empty and everything else is zero.
304 int id
, flags
, retries
;
306 unsigned long udpsent
; /* bitmap indexed by server */
307 struct timeval timeout
;
308 time_t expires
; /* Earliest expiry time of any record we used. */
314 * state Queue child id nextudpserver udpsent tcpfailed
316 * tosend NONE null >=0 0 zero zero
317 * tosend udpw null >=0 any nonzero zero
318 * tosend NONE null >=0 any nonzero zero
320 * tcpw tcpw null >=0 irrelevant any any
322 * child childw set >=0 irrelevant irrelevant irrelevant
323 * child NONE null >=0 irrelevant irrelevant irrelevant
324 * done output null -1 irrelevant irrelevant irrelevant
326 * Queries are only not on a queue when they are actually being processed.
327 * Queries in state tcpw/tcpw have been sent (or are in the to-send buffer)
328 * iff the tcp connection is in state server_ok.
330 * +------------------------+
331 * START -----> | tosend/NONE |
332 * +------------------------+
334 * too big for UDP / UDP timeout \ \ send via UDP
335 * send via TCP / more retries \ \
336 * when conn'd / desired \ \
339 * +-----------+ +-------------+
340 * | tcpw/tcpw | ________ | tosend/udpw |
341 * +-----------+ \ +-------------+
342 * | | | UDP timeout | |
345 * \ | TCP died | desired | |
347 * \ \ servers | TCP / |
348 * \ \ to try | timeout / |
350 * reply \ _| +------------------+ / reply
351 * \ | done/output FAIL | /
352 * \ +------------------+ /
355 * (..... got reply ....)
357 * need child query/ies / \ no child query
360 * +---------------+ +----------------+
361 * | childw/childw | ----------------> | done/output OK |
362 * +---------------+ children done +----------------+
366 struct query_queue
{ adns_query head
, tail
; };
371 adns_initflags iflags
;
372 adns_logcallbackfn
*logfn
;
375 struct query_queue udpw
, tcpw
, childw
, output
;
376 adns_query forallnext
;
377 int nextid
, tcpsocket
;
378 struct udpsocket
{ int af
; int fd
; } udpsocket
[MAXUDP
];
380 vbuf tcpsend
, tcprecv
;
381 int nservers
, nsortlist
, nsearchlist
, searchndots
, tcpserver
, tcprecv_skip
;
382 enum adns__tcpstate
{
383 server_disconnected
, server_connecting
,
384 server_ok
, server_broken
386 struct timeval tcptimeout
;
387 /* This will have tv_sec==0 if it is not valid. It will always be
388 * valid if tcpstate _connecting. When _ok, it will be nonzero if
389 * we are idle (ie, tcpw queue is empty), in which case it is the
390 * absolute time when we will close the connection.
392 struct sigaction stdsigpipe
;
394 struct pollfd pollfds_buf
[MAX_POLLFDS
];
395 adns_rr_addr servers
[MAXSERVERS
];
398 union gen_addr base
, mask
;
399 } sortlist
[MAXSORTLIST
];
401 unsigned short rand48xsubi
[3];
404 /* From addrfam.c: */
406 extern int adns__af_supported_p(int af
);
407 /* Return nonzero if the address family af known to the library and supported
408 * by the other addrfam operations. Note that the other operations will
409 * abort on an unrecognized address family rather than returning an error
413 extern int adns__genaddr_equal_p(int af
, const union gen_addr
*a
,
414 int bf
, const void *b
);
415 /* b should point to a `struct in_addr' or equivalent for the address family
416 * bf. Returns nonzero if the two addresses are equal.
419 extern int adns__sockaddr_equal_p(const struct sockaddr
*sa
,
420 const struct sockaddr
*sb
);
421 /* Return nonzero if the two socket addresses are equal (in all significant
425 extern int adns__addr_width(int af
);
426 /* Return the width of addresses of family af, in bits. */
428 extern void adns__prefix_mask(int af
, int len
, union gen_addr
*mask_r
);
429 /* Store in mask_r an address mask for address family af, whose first len
430 * bits are set and the remainder are clear. This is what you want for
431 * converting a prefix length into a netmask.
434 extern int adns__guess_prefix_length(int af
, const union gen_addr
*addr
);
435 /* Given a network base address, guess the appropriate prefix length based on
436 * the appropriate rules for the address family (e.g., for IPv4, this uses
437 * the old address classes).
440 extern int adns__addr_match_p(int addraf
, const union gen_addr
*addr
,
441 int netaf
, const union gen_addr
*base
,
442 const union gen_addr
*mask
);
443 /* Given an address af (with family addraf) and a network (with family netaf,
444 * base address base, and netmask mask), return nonzero if the address lies
445 * within the network.
448 extern void adns__sockaddr_extract(const struct sockaddr
*sa
,
449 union gen_addr
*a_r
, int *port_r
);
450 /* Extract fields from the socket address, filling in *a_r and *port_r with
451 * the address and (integer, host byte-order) port number, respectively.
452 * Either (or, pointlessly, both) of a_r and port_r may be null to mean
456 extern void adns__sockaddr_inject(const union gen_addr
*a
, int port
,
457 struct sockaddr
*sa
);
458 /* Inject fields into the socket adress sa. If a is not null, copy the
459 * address in; if port is not -1, then copy the port (converting from host
460 * byte-order). Assumes that sa->sa_family is already set correctly.
463 char *adns__sockaddr_ntoa(const struct sockaddr
*sa
, char *buf
);
464 /* Convert sa to a string, and write it to buf, which must be at least
465 * ADNS_ADDR2TEXT_BUFLEN bytes long (unchecked). Return buf; can't fail.
468 extern int adns__make_reverse_domain(const struct sockaddr
*sa
,
470 char **buf_io
, size_t bufsz
,
472 /* Construct a reverse domain string, given a socket address and a parent
473 * zone. If zone is null, then use the standard reverse-lookup zone for the
474 * address family. If the length of the resulting string is no larger than
475 * bufsz, then the result is stored starting at *buf_io; otherwise a new
476 * buffer is allocated is used, and a pointer to it is stored in both *buf_io
477 * and *buf_free_r (the latter of which should be null on entry). If
478 * something goes wrong, then an errno value is returned: ENOSYS if the
479 * address family of sa isn't recognized, or ENOMEM if the attempt to
480 * allocate an output buffer failed.
483 extern int adns__revparse_label(struct revparse_state
*rps
, int labnum
,
484 const char *label
, int lablen
);
485 /* Parse a label in a reverse-domain name, given its index labnum (starting
486 * from zero), a pointer to its contents (which need not be null-terminated),
487 * and its length. The state in *rps is initialized implicitly when labnum
490 * Returns zero if the parse was successful, nonzero if the domain name is
491 * definitely invalid and the parse must be abandoned.
494 extern int adns__revparse_done(struct revparse_state
*rps
, int nlabels
,
495 adns_rrtype
*rrtype_r
, struct af_addr
*addr_r
);
496 /* Finishes parsing a reverse-domain name, given the total number of labels
497 * in the name. On success, fills in the address in *addr_r, and the forward
498 * query type in *rrtype_r (because that turns out to be useful). Returns
499 * nonzero if the parse must be abandoned.
504 int adns__setnonblock(adns_state ads
, int fd
); /* => errno value */
506 /* From general.c: */
508 void adns__vlprintf(adns_state ads
, const char *fmt
, va_list al
);
509 void adns__lprintf(adns_state ads
, const char *fmt
,
510 ...) PRINTFFORMAT(2,3);
512 void adns__vdiag(adns_state ads
, const char *pfx
, adns_initflags prevent
,
513 int serv
, adns_query qu
, const char *fmt
, va_list al
);
515 void adns__debug(adns_state ads
, int serv
, adns_query qu
,
516 const char *fmt
, ...) PRINTFFORMAT(4,5);
517 void adns__warn(adns_state ads
, int serv
, adns_query qu
,
518 const char *fmt
, ...) PRINTFFORMAT(4,5);
519 void adns__diag(adns_state ads
, int serv
, adns_query qu
,
520 const char *fmt
, ...) PRINTFFORMAT(4,5);
522 int adns__vbuf_ensure(vbuf
*vb
, int want
);
523 int adns__vbuf_appendstr(vbuf
*vb
, const char *data
); /* doesn't include nul */
524 int adns__vbuf_append(vbuf
*vb
, const byte
*data
, int len
);
525 /* 1=>success, 0=>realloc failed */
526 void adns__vbuf_appendq(vbuf
*vb
, const byte
*data
, int len
);
527 void adns__vbuf_init(vbuf
*vb
);
528 void adns__vbuf_free(vbuf
*vb
);
530 const char *adns__diag_domain(adns_state ads
, int serv
, adns_query qu
,
532 const byte
*dgram
, int dglen
, int cbyte
);
533 /* Unpicks a domain in a datagram and returns a string suitable for
534 * printing it as. Never fails - if an error occurs, it will
535 * return some kind of string describing the error.
537 * serv may be -1 and qu may be 0. vb must have been initialised,
538 * and will be left in an arbitrary consistent state.
540 * Returns either vb->buf, or a pointer to a string literal. Do not modify
541 * vb before using the return value.
544 int adns__getrrsz_default(const typeinfo
*typei
, adns_rrtype type
);
545 /* Default function for the `getrrsz' type hook; returns the `fixed_rrsz'
546 * value from the typeinfo entry.
549 void adns__isort(void *array
, int nobjs
, int sz
, void *tempbuf
,
550 int (*needswap
)(void *context
, const void *a
, const void *b
),
552 /* Does an insertion sort of array which must contain nobjs objects
553 * each sz bytes long. tempbuf must point to a buffer at least
554 * sz bytes long. needswap should return !0 if a>b (strictly, ie
555 * wrong order) 0 if a<=b (ie, order is fine).
558 void adns__sigpipe_protect(adns_state
);
559 void adns__sigpipe_unprotect(adns_state
);
560 /* If SIGPIPE protection is not disabled, will block all signals except
561 * SIGPIPE, and set SIGPIPE's disposition to SIG_IGN. (And then restore.)
562 * Each call to _protect must be followed by a call to _unprotect before
563 * any significant amount of code gets to run, since the old signal mask
564 * is stored in the adns structure.
567 /* From transmit.c: */
569 adns_status
adns__mkquery(adns_state ads
, vbuf
*vb
, int *id_r
,
570 const char *owner
, int ol
,
571 const typeinfo
*typei
, adns_rrtype type
,
572 adns_queryflags flags
);
573 /* Assembles a query packet in vb. A new id is allocated and returned.
576 adns_status
adns__mkquery_frdgram(adns_state ads
, vbuf
*vb
, int *id_r
,
577 const byte
*qd_dgram
, int qd_dglen
,
579 adns_rrtype type
, adns_queryflags flags
);
580 /* Same as adns__mkquery, but takes the owner domain from an existing datagram.
581 * That domain must be correct and untruncated.
584 void adns__querysend_tcp(adns_query qu
, struct timeval now
);
585 /* Query must be in state tcpw/tcpw; it will be sent if possible and
586 * no further processing can be done on it for now. The connection
587 * might be broken, but no reconnect will be attempted.
590 struct udpsocket
*adns__udpsocket_by_af(adns_state ads
, int af
);
591 /* Find the UDP socket structure in ads which has the given address family.
592 * Return null if there isn't one.
594 * This is used during initialization, so ads is only partially filled in.
595 * The requirements are that nudp is set, and that udpsocket[i].af are
596 * defined for 0<=i<nudp.
599 void adns__query_send(adns_query qu
, struct timeval now
);
600 /* Query must be in state tosend/NONE; it will be moved to a new state,
601 * and no further processing can be done on it for now.
602 * (Resulting state is one of udp/timew, tcpwait/timew (if server not
603 * connected), tcpsent/timew, child/childw or done/output.)
604 * __query_send may decide to use either UDP or TCP depending whether
605 * _qf_usevc is set (or has become set) and whether the query is too
611 adns_status
adns__internal_submit(adns_state ads
, adns_query
*query_r
,
612 const typeinfo
*typei
, adns_rrtype type
,
613 vbuf
*qumsg_vb
, int id
,
614 adns_queryflags flags
, struct timeval now
,
616 /* Submits a query (for internal use, called during external submits).
618 * The new query is returned in *query_r, or we return adns_s_nomemory.
620 * The query datagram should already have been assembled in qumsg_vb;
621 * the memory for it is _taken over_ by this routine whether it
622 * succeeds or fails (if it succeeds, the vbuf is reused for qu->vb).
624 * *ctx is copied byte-for-byte into the query. Before doing this, its tinfo
625 * field may be modified by type hooks.
627 * When the child query is done, ctx->callback will be called. The
628 * child will already have been taken off both the global list of
629 * queries in ads and the list of children in the parent. The child
630 * will be freed when the callback returns. The parent will have been
631 * taken off the global childw queue.
633 * The callback should either call adns__query_done, if it is
634 * complete, or adns__query_fail, if an error has occurred, in which
635 * case the other children (if any) will be cancelled. If the parent
636 * has more unfinished children (or has just submitted more) then the
637 * callback may choose to wait for them - it must then put the parent
638 * back on the childw queue.
641 void adns__search_next(adns_state ads
, adns_query qu
, struct timeval now
);
642 /* Walks down the searchlist for a query with adns_qf_search.
643 * The query should have just had a negative response, or not had
644 * any queries sent yet, and should not be on any queue.
645 * The query_dgram if any will be freed and forgotten and a new
646 * one constructed from the search_* members of the query.
648 * Cannot fail (in case of error, calls adns__query_fail).
651 void *adns__alloc_interim(adns_query qu
, size_t sz
);
652 void *adns__alloc_preserved(adns_query qu
, size_t sz
);
653 /* Allocates some memory, and records which query it came from
654 * and how much there was.
656 * If an error occurs in the query, all the memory from _interim is
657 * simply freed. If the query succeeds, one large buffer will be made
658 * which is big enough for all these allocations, and then
659 * adns__alloc_final will get memory from this buffer.
661 * _alloc_interim can fail (and return 0).
662 * The caller must ensure that the query is failed.
664 * The memory from _preserved is is kept and transferred into the
665 * larger buffer - unless we run out of memory, in which case it too
666 * is freed. When you use _preserved you have to add code to the
667 * x_nomem error exit case in adns__makefinal_query to clear out the
668 * pointers you made to those allocations, because that's when they're
669 * thrown away; you should also make a note in the declaration of
670 * those pointer variables, to note that they are _preserved rather
671 * than _interim. If they're in the answer, note it here:
672 * answer->cname and answer->owner are _preserved.
675 void adns__transfer_interim(adns_query from
, adns_query to
, void *block
);
676 /* Transfers an interim allocation from one query to another, so that
677 * the `to' query will have room for the data when we get to makefinal
678 * and so that the free will happen when the `to' query is freed
679 * rather than the `from' query.
681 * It is legal to call adns__transfer_interim with a null pointer; this
684 * _transfer_interim also ensures that the expiry time of the `to' query
685 * is no later than that of the `from' query, so that child queries'
686 * TTLs get inherited by their parents.
689 void adns__free_interim(adns_query qu
, void *p
);
690 /* Forget about a block allocated by adns__alloc_interim.
693 void *adns__alloc_mine(adns_query qu
, size_t sz
);
694 /* Like _interim, but does not record the length for later
695 * copying into the answer. This just ensures that the memory
696 * will be freed when we're done with the query.
699 void *adns__alloc_final(adns_query qu
, size_t sz
);
700 /* Cannot fail, and cannot return 0.
703 void adns__makefinal_block(adns_query qu
, void **blpp
, size_t sz
);
704 void adns__makefinal_str(adns_query qu
, char **strp
);
706 void adns__reset_preserved(adns_query qu
);
707 /* Resets all of the memory management stuff etc. to take account of
708 * only the _preserved stuff from _alloc_preserved. Used when we find
709 * an error somewhere and want to just report the error (with perhaps
710 * CNAME, owner, etc. info), and also when we're halfway through RRs
711 * in a datagram and discover that we need to retry the query.
714 void adns__query_done(adns_query qu
);
715 void adns__query_fail(adns_query qu
, adns_status stat
);
716 void adns__cancel_children(adns_query qu
);
720 void adns__procdgram(adns_state ads
, const byte
*dgram
, int len
,
721 int serv
, int viatcp
, struct timeval now
);
722 /* This function is allowed to cause new datagrams to be constructed
723 * and sent, or even new queries to be started. However,
724 * query-sending functions are not allowed to call any general event
725 * loop functions in case they accidentally call this.
727 * Ie, receiving functions may call sending functions.
728 * Sending functions may NOT call receiving functions.
733 const typeinfo
*adns__findtype(adns_rrtype type
);
742 int dglen
, max
, cbyte
, namelen
;
746 void adns__findlabel_start(findlabel_state
*fls
, adns_state ads
,
747 int serv
, adns_query qu
,
748 const byte
*dgram
, int dglen
, int max
,
749 int dmbegin
, int *dmend_rlater
);
750 /* Finds labels in a domain in a datagram.
752 * Call this routine first.
753 * dmend_rlater may be null. ads (and of course fls) may not be.
754 * serv may be -1, qu may be null - they are for error reporting.
757 adns_status
adns__findlabel_next(findlabel_state
*fls
,
758 int *lablen_r
, int *labstart_r
);
759 /* Then, call this one repeatedly.
761 * It will return adns_s_ok if all is well, and tell you the length
762 * and start of successive labels. labstart_r may be null, but
763 * lablen_r must not be.
765 * After the last label, it will return with *lablen_r zero.
766 * Do not then call it again; instead, just throw away the findlabel_state.
768 * *dmend_rlater will have been set to point to the next part of
769 * the datagram after the label (or after the uncompressed part,
770 * if compression was used). *namelen_rlater will have been set
771 * to the length of the domain name (total length of labels plus
772 * 1 for each intervening dot).
774 * If the datagram appears to be truncated, *lablen_r will be -1.
775 * *dmend_rlater, *labstart_r and *namelen_r may contain garbage.
776 * Do not call _next again.
778 * There may also be errors, in which case *dmend_rlater,
779 * *namelen_rlater, *lablen_r and *labstart_r may contain garbage.
780 * Do not then call findlabel_next again.
787 adns_status
adns__parse_domain(adns_state ads
, int serv
, adns_query qu
,
788 vbuf
*vb
, parsedomain_flags flags
,
789 const byte
*dgram
, int dglen
, int *cbyte_io
,
791 /* vb must already have been initialised; it will be reset if necessary.
792 * If there is truncation, vb->used will be set to 0; otherwise
793 * (if there is no error) vb will be null-terminated.
794 * If there is an error vb and *cbyte_io may be left indeterminate.
796 * serv may be -1 and qu may be 0 - they are used for error reporting only.
799 adns_status
adns__parse_domain_more(findlabel_state
*fls
, adns_state ads
,
800 adns_query qu
, vbuf
*vb
,
801 parsedomain_flags flags
,
803 /* Like adns__parse_domain, but you pass it a pre-initialised findlabel_state,
804 * for continuing an existing domain or some such of some kind. Also, unlike
805 * _parse_domain, the domain data will be appended to vb, rather than replacing
806 * the existing contents.
809 adns_status
adns__findrr(adns_query qu
, int serv
,
810 const byte
*dgram
, int dglen
, int *cbyte_io
,
811 int *type_r
, int *class_r
, unsigned long *ttl_r
,
812 int *rdlen_r
, int *rdstart_r
,
813 int *ownermatchedquery_r
);
814 /* Finds the extent and some of the contents of an RR in a datagram
815 * and does some checks. The datagram is *dgram, length dglen, and
816 * the RR starts at *cbyte_io (which is updated afterwards to point
817 * to the end of the RR).
819 * The type, class, TTL and RRdata length and start are returned iff
820 * the corresponding pointer variables are not null. type_r, class_r
821 * and ttl_r may not be null. The TTL will be capped.
823 * If ownermatchedquery_r != 0 then the owner domain of this
824 * RR will be compared with that in the query (or, if the query
825 * has gone to a CNAME lookup, with the canonical name).
826 * In this case, *ownermatchedquery_r will be set to 0 or 1.
827 * The query datagram (or CNAME datagram) MUST be valid and not truncated.
829 * If there is truncation then *type_r will be set to -1 and
830 * *cbyte_io, *class_r, *rdlen_r, *rdstart_r and *eo_matched_r will be
833 * qu must obviously be non-null.
835 * If an error is returned then *type_r will be undefined too.
838 adns_status
adns__findrr_anychk(adns_query qu
, int serv
,
839 const byte
*dgram
, int dglen
, int *cbyte_io
,
840 int *type_r
, int *class_r
,
841 unsigned long *ttl_r
,
842 int *rdlen_r
, int *rdstart_r
,
843 const byte
*eo_dgram
, int eo_dglen
,
844 int eo_cbyte
, int *eo_matched_r
);
845 /* Like adns__findrr_checked, except that the datagram and
846 * owner to compare with can be specified explicitly.
848 * If the caller thinks they know what the owner of the RR ought to
849 * be they can pass in details in eo_*: this is another (or perhaps
850 * the same datagram), and a pointer to where the putative owner
851 * starts in that datagram. In this case *eo_matched_r will be set
852 * to 1 if the datagram matched or 0 if it did not. Either
853 * both eo_dgram and eo_matched_r must both be non-null, or they
854 * must both be null (in which case eo_dglen and eo_cbyte will be ignored).
855 * The eo datagram and contained owner domain MUST be valid and
859 void adns__update_expires(adns_query qu
, unsigned long ttl
,
861 /* Updates the `expires' field in the query, so that it doesn't exceed
865 int vbuf__append_quoted1035(vbuf
*vb
, const byte
*buf
, int len
);
869 void adns__tcp_broken(adns_state ads
, const char *what
, const char *why
);
870 /* what and why may be both 0, or both non-0. */
872 void adns__tcp_tryconnect(adns_state ads
, struct timeval now
);
874 void adns__autosys(adns_state ads
, struct timeval now
);
875 /* Make all the system calls we want to if the application wants us to.
876 * Must not be called from within adns internal processing functions,
877 * lest we end up in recursive descent !
880 void adns__must_gettimeofday(adns_state ads
, const struct timeval
**now_io
,
881 struct timeval
*tv_buf
);
883 int adns__pollfds(adns_state ads
, struct pollfd pollfds_buf
[MAX_POLLFDS
]);
884 void adns__fdevents(adns_state ads
,
885 const struct pollfd
*pollfds
, int npollfds
,
886 int maxfd
, const fd_set
*readfds
,
887 const fd_set
*writefds
, const fd_set
*exceptfds
,
888 struct timeval now
, int *r_r
);
889 int adns__internal_check(adns_state ads
,
890 adns_query
*query_io
,
891 adns_answer
**answer
,
894 void adns__timeouts(adns_state ads
, int act
,
895 struct timeval
**tv_io
, struct timeval
*tvbuf
,
897 /* If act is !0, then this will also deal with the TCP connection
898 * if previous events broke it or require it to be connected.
903 void adns__consistency(adns_state ads
, adns_query qu
, consistency_checks cc
);
905 /* Useful static inline functions: */
907 static inline int ctype_whitespace(int c
) {
908 return c
==' ' || c
=='\n' || c
=='\t';
910 static inline int ctype_digit(int c
) { return c
>='0' && c
<='9'; }
911 static inline int ctype_alpha(int c
) {
912 return (c
>= 'a' && c
<= 'z') || (c
>= 'A' && c
<= 'Z');
914 static inline int ctype_822special(int c
) {
915 return strchr("()<>@,;:\\\".[]",c
) != 0;
917 static inline int ctype_domainunquoted(int c
) {
918 return ctype_alpha(c
) || ctype_digit(c
) || (strchr("-_/+",c
) != 0);
921 static inline int errno_resources(int e
) { return e
==ENOMEM
|| e
==ENOBUFS
; }
925 #define MEM_ROUND(sz) \
926 (( ((sz)+sizeof(union maxalign)-1) / sizeof(union maxalign) ) \
927 * sizeof(union maxalign) )
929 #define GETIL_B(cb) (((dgram)[(cb)++]) & 0x0ff)
930 #define GET_B(cb,tv) ((tv)= GETIL_B((cb)))
931 #define GET_W(cb,tv) ((tv)=0,(tv)|=(GETIL_B((cb))<<8), (tv)|=GETIL_B(cb), (tv))
932 #define GET_L(cb,tv) ( (tv)=0, \
933 (tv)|=(GETIL_B((cb))<<24), \
934 (tv)|=(GETIL_B((cb))<<16), \
935 (tv)|=(GETIL_B((cb))<<8), \