[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent/DNS.pm

Comparing AnyEvent/lib/AnyEvent/DNS.pm (file contents):
Revision 1.9 by root, Fri May 23 06:02:16 2008 UTC vs.
Revision 1.53 by root, Fri May 30 09:40:41 2008 UTC

…		…
3	AnyEvent::DNS - fully asynchronous DNS resolution	3	AnyEvent::DNS - fully asynchronous DNS resolution
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use AnyEvent::DNS;	7	use AnyEvent::DNS;
		8
		9	my $cv = AnyEvent->condvar;
		10	AnyEvent::DNS::a "www.google.de", $cv;
		11	# ... later
		12	my @addrs = $cv->recv;
8		13
9	=head1 DESCRIPTION	14	=head1 DESCRIPTION
10		15
11	This module offers both a number of DNS convenience functions as well	16	This module offers both a number of DNS convenience functions as well
12	as a fully asynchronous and high-performance pure-perl stub resolver.	17	as a fully asynchronous and high-performance pure-perl stub resolver.
13		18
		19	The stub resolver supports DNS over IPv4 and IPv6, UDP and TCP, optional
		20	EDNS0 support for up to 4kiB datagrams and automatically falls back to
		21	virtual circuit mode for large responses.
		22
14	=head2 CONVENIENCE FUNCTIONS	23	=head2 CONVENIENCE FUNCTIONS
15		24
16	=over 4	25	=over 4
17		26
18	=cut	27	=cut
…		…
20	package AnyEvent::DNS;	29	package AnyEvent::DNS;
21		30
22	no warnings;	31	no warnings;
23	use strict;	32	use strict;
24		33
		34	use Socket qw(AF_INET SOCK_DGRAM SOCK_STREAM);
		35
25	use AnyEvent::Util ();	36	use AnyEvent ();
26	use AnyEvent::Handle ();	37	use AnyEvent::Handle ();
		38	use AnyEvent::Util qw(AF_INET6);
27		39
28	=item AnyEvent::DNS::addr $node, $service, $family, $type, $cb->(@addrs)	40	our $VERSION = '1.0';
29		41
30	NOT YET IMPLEMENTED	42	our @DNS_FALLBACK = (v208.67.220.220, v208.67.222.222);
31
32	Tries to resolve the given nodename and service name into sockaddr
33	structures usable to connect to this node and service in a
34	protocol-independent way. It works similarly to the getaddrinfo posix
35	function.
36
37	Example:
38
39	AnyEvent::DNS::addr "google.com", "http", AF_UNSPEC, SOCK_STREAM, sub { ... };
40		43
41	=item AnyEvent::DNS::a $domain, $cb->(@addrs)	44	=item AnyEvent::DNS::a $domain, $cb->(@addrs)
42		45
43	Tries to resolve the given domain to IPv4 address(es).	46	Tries to resolve the given domain to IPv4 address(es).
		47
		48	=item AnyEvent::DNS::aaaa $domain, $cb->(@addrs)
		49
		50	Tries to resolve the given domain to IPv6 address(es).
44		51
45	=item AnyEvent::DNS::mx $domain, $cb->(@hostnames)	52	=item AnyEvent::DNS::mx $domain, $cb->(@hostnames)
46		53
47	Tries to resolve the given domain into a sorted (lower preference value	54	Tries to resolve the given domain into a sorted (lower preference value
48	first) list of domain names.	55	first) list of domain names.
…		…
58	=item AnyEvent::DNS::srv $service, $proto, $domain, $cb->(@srv_rr)	65	=item AnyEvent::DNS::srv $service, $proto, $domain, $cb->(@srv_rr)
59		66
60	Tries to resolve the given service, protocol and domain name into a list	67	Tries to resolve the given service, protocol and domain name into a list
61	of service records.	68	of service records.
62		69
63	Each srv_rr is an arrayref with the following contents:	70	Each srv_rr is an array reference with the following contents:
64	C<[$priority, $weight, $transport, $target]>.	71	C<[$priority, $weight, $transport, $target]>.
65		72
66	They will be sorted with lowest priority, highest weight first (TODO:	73	They will be sorted with lowest priority first, then randomly
67	should use the rfc algorithm to reorder same-priority records for weight).	74	distributed by weight as per RFC 2782.
68		75
69	Example:	76	Example:
70		77
71	AnyEvent::DNS::srv "sip", "udp", "schmorp.de", sub { ...	78	AnyEvent::DNS::srv "sip", "udp", "schmorp.de", sub { ...
72	# @_ = ( [10, 10, 5060, "sip1.schmorp.de" ] )	79	# @_ = ( [10, 10, 5060, "sip1.schmorp.de" ] )
73		80
74	=item AnyEvent::DNS::ptr $ipv4_or_6, $cb->(@hostnames)	81	=item AnyEvent::DNS::ptr $domain, $cb->(@hostnames)
		82
		83	Tries to make a PTR lookup on the given domain. See C<reverse_lookup>
		84	and C<reverse_verify> if you want to resolve an IP address to a hostname
		85	instead.
		86
		87	=item AnyEvent::DNS::any $domain, $cb->(@rrs)
		88
		89	Tries to resolve the given domain and passes all resource records found to
		90	the callback.
		91
		92	=item AnyEvent::DNS::reverse_lookup $ipv4_or_6, $cb->(@hostnames)
75		93
76	Tries to reverse-resolve the given IPv4 or IPv6 address (in textual form)	94	Tries to reverse-resolve the given IPv4 or IPv6 address (in textual form)
77	into it's hostname(s).	95	into it's hostname(s). Handles V4MAPPED and V4COMPAT IPv6 addresses
		96	transparently.
78		97
79	Requires the Socket6 module for IPv6 support.	98	=item AnyEvent::DNS::reverse_verify $ipv4_or_6, $cb->(@hostnames)
		99
		100	The same as C<reverse_lookup>, but does forward-lookups to verify that
		101	the resolved hostnames indeed point to the address, which makes spoofing
		102	harder.
		103
		104	If you want to resolve an address into a hostname, this is the preferred
		105	method: The DNS records could still change, but at least this function
		106	verified that the hostname, at one point in the past, pointed at the IP
		107	address you originally resolved.
80		108
81	Example:	109	Example:
82		110
83	AnyEvent::DNS::ptr "2001:500:2f::f", sub { print shift };	111	AnyEvent::DNS::ptr "2001:500:2f::f", sub { print shift };
84	# => f.root-servers.net	112	# => f.root-servers.net
85		113
86	=item AnyEvent::DNS::any $domain, $cb->(@rrs)
87
88	Tries to resolve the given domain and passes all resource records found to
89	the callback.
90
91	=cut	114	=cut
		115
		116	sub MAX_PKT() { 4096 } # max packet size we advertise and accept
		117
		118	sub DOMAIN_PORT() { 53 } # if this changes drop me a note
92		119
93	sub resolver;	120	sub resolver;
94		121
95	sub a($$) {	122	sub a($$) {
96	my ($domain, $cb) = @_;	123	my ($domain, $cb) = @_;
…		…
98	resolver->resolve ($domain => "a", sub {	125	resolver->resolve ($domain => "a", sub {
99	$cb->(map $_->[3], @_);	126	$cb->(map $_->[3], @_);
100	});	127	});
101	}	128	}
102		129
		130	sub aaaa($$) {
		131	my ($domain, $cb) = @_;
		132
		133	resolver->resolve ($domain => "aaaa", sub {
		134	$cb->(map $_->[3], @_);
		135	});
		136	}
		137
103	sub mx($$) {	138	sub mx($$) {
104	my ($domain, $cb) = @_;	139	my ($domain, $cb) = @_;
105		140
106	resolver->resolve ($domain => "mx", sub {	141	resolver->resolve ($domain => "mx", sub {
107	$cb->(map $_->[4], sort { $a->[3] <=> $b->[3] } @_);	142	$cb->(map $_->[4], sort { $a->[3] <=> $b->[3] } @_);
…		…
127	sub srv($$$$) {	162	sub srv($$$$) {
128	my ($service, $proto, $domain, $cb) = @_;	163	my ($service, $proto, $domain, $cb) = @_;
129		164
130	# todo, ask for any and check glue records	165	# todo, ask for any and check glue records
131	resolver->resolve ("_$service._$proto.$domain" => "srv", sub {	166	resolver->resolve ("_$service._$proto.$domain" => "srv", sub {
132	$cb->(map [@$_[3,4,5,6]], sort { $a->[3] <=> $b->[3] \|\| $b->[4] <=> $a->[4] } @_);	167	my @res;
		168
		169	# classify by priority
		170	my %pri;
		171	push @{ $pri{$_->[3]} }, [ @$_[3,4,5,6] ]
		172	for @_;
		173
		174	# order by priority
		175	for my $pri (sort { $a->[0] <=> $b->[0] } keys %pri) {
		176	# order by weight
		177	my @rr = sort { $a->[1] <=> $b->[1] } @{ delete $pri{$pri} };
		178
		179	my $sum; $sum += $_->[1] for @rr;
		180
		181	while (@rr) {
		182	my $w = int rand $sum + 1;
		183	for (0 .. $#rr) {
		184	if (($w -= $rr[$_][1]) <= 0) {
		185	$sum -= $rr[$_][1];
		186	push @res, splice @rr, $_, 1, ();
		187	last;
		188	}
		189	}
		190	}
		191	}
		192
		193	$cb->(@res);
133	});	194	});
134	}	195	}
135		196
136	sub ptr($$) {	197	sub ptr($$) {
137	my ($ip, $cb) = @_;	198	my ($domain, $cb) = @_;
138		199
139	my $name;
140
141	if (AnyEvent::Util::dotted_quad $ip) {
142	$name = join ".", (reverse split /\./, $ip), "in-addr.arpa.";
143	} else {
144	require Socket6;
145	$name = join ".",
146	(reverse split //,
147	unpack "H*", Socket6::inet_pton (Socket::AF_INET6, $ip)),
148	"ip6.arpa.";
149	}
150
151	resolver->resolve ($name => "ptr", sub {	200	resolver->resolve ($domain => "ptr", sub {
152	$cb->(map $_->[3], @_);	201	$cb->(map $_->[3], @_);
153	});	202	});
154	}	203	}
155		204
156	sub any($$) {	205	sub any($$) {
157	my ($domain, $cb) = @_;	206	my ($domain, $cb) = @_;
158		207
159	resolver->resolve ($domain => "*", $cb);	208	resolver->resolve ($domain => "*", $cb);
160	}	209	}
161		210
		211	# convert textual ip address into reverse lookup form
		212	sub _munge_ptr($) {
		213	my $ipn = $_[0]
		214	or return;
		215
		216	my $ptr;
		217
		218	my $af = AnyEvent::Socket::address_family ($ipn);
		219
		220	if ($af == AF_INET6) {
		221	$ipn = substr $ipn, 0, 16; # anticipate future expansion
		222
		223	# handle v4mapped and v4compat
		224	if ($ipn =~ s/^\x00{10}(?:\xff\xff\|\x00\x00)//) {
		225	$af = AF_INET;
		226	} else {
		227	$ptr = join ".", (reverse split //, unpack "H32", $ipn), "ip6.arpa.";
		228	}
		229	}
		230
		231	if ($af == AF_INET) {
		232	$ptr = join ".", (reverse unpack "C4", $ipn), "in-addr.arpa.";
		233	}
		234
		235	$ptr
		236	}
		237
		238	sub reverse_lookup($$) {
		239	my ($ip, $cb) = @_;
		240
		241	$ip = _munge_ptr AnyEvent::Socket::parse_address ($ip)
		242	or return $cb->();
		243
		244	resolver->resolve ($ip => "ptr", sub {
		245	$cb->(map $_->[3], @_);
		246	});
		247	}
		248
		249	sub reverse_verify($$) {
		250	my ($ip, $cb) = @_;
		251
		252	my $ipn = AnyEvent::Socket::parse_address ($ip)
		253	or return $cb->();
		254
		255	my $af = AnyEvent::Socket::address_family ($ipn);
		256
		257	my @res;
		258	my $cnt;
		259
		260	my $ptr = _munge_ptr $ipn
		261	or return $cb->();
		262
		263	$ip = AnyEvent::Socket::format_address ($ipn); # normalise into the same form
		264
		265	ptr $ptr, sub {
		266	for my $name (@_) {
		267	++$cnt;
		268
		269	# () around AF_INET to work around bug in 5.8
		270	resolver->resolve ($name => ($af == (AF_INET) ? "a" : "aaaa"), sub {
		271	for (@_) {
		272	push @res, $name
		273	if $_->[3] eq $ip;
		274	}
		275	$cb->(@res) unless --$cnt;
		276	});
		277	}
		278
		279	$cb->() unless $cnt;
		280	};
		281	}
		282
		283	#################################################################################
		284
		285	=back
		286
162	=head2 DNS EN-/DECODING FUNCTIONS	287	=head2 LOW-LEVEL DNS EN-/DECODING FUNCTIONS
163		288
164	=over 4	289	=over 4
165		290
		291	=item $AnyEvent::DNS::EDNS0
		292
		293	This variable decides whether dns_pack automatically enables EDNS0
		294	support. By default, this is disabled (C<0>), unless overridden by
		295	C<$ENV{PERL_ANYEVENT_EDNS0}>, but when set to C<1>, AnyEvent::DNS will use
		296	EDNS0 in all requests.
		297
166	=cut	298	=cut
		299
		300	our $EDNS0 = $ENV{PERL_ANYEVENT_EDNS0} * 1; # set to 1 to enable (partial) edns0
167		301
168	our %opcode_id = (	302	our %opcode_id = (
169	query => 0,	303	query => 0,
170	iquery => 1,	304	iquery => 1,
171	status => 2,	305	status => 2,
…		…
217	minfo => 14,	351	minfo => 14,
218	mx => 15,	352	mx => 15,
219	txt => 16,	353	txt => 16,
220	aaaa => 28,	354	aaaa => 28,
221	srv => 33,	355	srv => 33,
		356	naptr => 35, # rfc2915
222	opt => 41,	357	opt => 41,
223	spf => 99,	358	spf => 99,
224	tkey => 249,	359	tkey => 249,
225	tsig => 250,	360	tsig => 250,
226	ixfr => 251,	361	ixfr => 251,
…		…
239	"*" => 255,	374	"*" => 255,
240	);	375	);
241		376
242	our %class_str = reverse %class_id;	377	our %class_str = reverse %class_id;
243		378
244	# names MUST have a trailing dot
245	sub _enc_qname($) {	379	sub _enc_name($) {
246	pack "(C/a)*", (split /\./, shift), ""	380	pack "(C/a)", (split /\./, shift), ""
247	}	381	}
248		382
249	sub _enc_qd() {	383	sub _enc_qd() {
250	(_enc_qname $_->[0]) . pack "nn",	384	(_enc_name $_->[0]) . pack "nn",
251	($_->[1] > 0 ? $_->[1] : $type_id {$_->[1]}),	385	($_->[1] > 0 ? $_->[1] : $type_id {$_->[1]}),
252	($_->[2] > 0 ? $_->[2] : $class_id{$_->[2] \|\| "in"})	386	($_->[2] > 0 ? $_->[2] : $class_id{$_->[2] \|\| "in"})
253	}	387	}
254		388
255	sub _enc_rr() {	389	sub _enc_rr() {
256	die "encoding of resource records is not supported";	390	die "encoding of resource records is not supported";
257	}	391	}
258		392
259	=item $pkt = AnyEvent::DNS::dns_pack $dns	393	=item $pkt = AnyEvent::DNS::dns_pack $dns
260		394
261	Packs a perl data structure into a DNS packet. Reading RFC1034 is strongly	395	Packs a perl data structure into a DNS packet. Reading RFC 1035 is strongly
262	recommended, then everything will be totally clear. Or maybe not.	396	recommended, then everything will be totally clear. Or maybe not.
263		397
264	Resource records are not yet encodable.	398	Resource records are not yet encodable.
265		399
266	Examples:	400	Examples:
…		…
309	+ $rcode_id{$req->{rc}} * 0x0001,	443	+ $rcode_id{$req->{rc}} * 0x0001,
310		444
311	scalar @{ $req->{qd} \|\| [] },	445	scalar @{ $req->{qd} \|\| [] },
312	scalar @{ $req->{an} \|\| [] },	446	scalar @{ $req->{an} \|\| [] },
313	scalar @{ $req->{ns} \|\| [] },	447	scalar @{ $req->{ns} \|\| [] },
314	scalar @{ $req->{ar} \|\| [] }, # include EDNS0 option here	448	$EDNS0 + scalar @{ $req->{ar} \|\| [] }, # EDNS0 option included here
315		449
316	(join "", map _enc_qd, @{ $req->{qd} \|\| [] }),	450	(join "", map _enc_qd, @{ $req->{qd} \|\| [] }),
317	(join "", map _enc_rr, @{ $req->{an} \|\| [] }),	451	(join "", map _enc_rr, @{ $req->{an} \|\| [] }),
318	(join "", map _enc_rr, @{ $req->{ns} \|\| [] }),	452	(join "", map _enc_rr, @{ $req->{ns} \|\| [] }),
319	(join "", map _enc_rr, @{ $req->{ar} \|\| [] }),	453	(join "", map _enc_rr, @{ $req->{ar} \|\| [] }),
320		454
321	# (pack "C nnNn", 0, 41, 4096, 0, 0) # EDNS0, 4kiB udp payload size	455	($EDNS0 ? pack "C nnNn", 0, 41, MAX_PKT, 0, 0 : "") # EDNS0 option
322	}	456	}
323		457
324	our $ofs;	458	our $ofs;
325	our $pkt;	459	our $pkt;
326		460
327	# bitches	461	# bitches
328	sub _dec_qname {	462	sub _dec_name {
329	my @res;	463	my @res;
330	my $redir;	464	my $redir;
331	my $ptr = $ofs;	465	my $ptr = $ofs;
332	my $cnt;	466	my $cnt;
333		467
334	while () {	468	while () {
335	return undef if ++$cnt >= 256; # to avoid DoS attacks	469	return undef if ++$cnt >= 256; # to avoid DoS attacks
336		470
337	my $len = ord substr $pkt, $ptr++, 1;	471	my $len = ord substr $pkt, $ptr++, 1;
338		472
339	if ($len & 0xc0) {	473	if ($len >= 0xc0) {
340	$ptr++;	474	$ptr++;
341	$ofs = $ptr if $ptr > $ofs;	475	$ofs = $ptr if $ptr > $ofs;
342	$ptr = (unpack "n", substr $pkt, $ptr - 2, 2) & 0x3fff;	476	$ptr = (unpack "n", substr $pkt, $ptr - 2, 2) & 0x3fff;
343	} elsif ($len) {	477	} elsif ($len) {
344	push @res, substr $pkt, $ptr, $len;	478	push @res, substr $pkt, $ptr, $len;
…		…
349	}	483	}
350	}	484	}
351	}	485	}
352		486
353	sub _dec_qd {	487	sub _dec_qd {
354	my $qname = _dec_qname;	488	my $qname = _dec_name;
355	my ($qt, $qc) = unpack "nn", substr $pkt, $ofs; $ofs += 4;	489	my ($qt, $qc) = unpack "nn", substr $pkt, $ofs; $ofs += 4;
356	[$qname, $type_str{$qt} \|\| $qt, $class_str{$qc} \|\| $qc]	490	[$qname, $type_str{$qt} \|\| $qt, $class_str{$qc} \|\| $qc]
357	}	491	}
358		492
359	our %dec_rr = (	493	our %dec_rr = (
360	1 => sub { Socket::inet_ntoa $_ }, # a	494	1 => sub { join ".", unpack "C4", $_ }, # a
361	2 => sub { local $ofs = $ofs - length; _dec_qname }, # ns	495	2 => sub { local $ofs = $ofs - length; _dec_name }, # ns
362	5 => sub { local $ofs = $ofs - length; _dec_qname }, # cname	496	5 => sub { local $ofs = $ofs - length; _dec_name }, # cname
363	6 => sub {	497	6 => sub {
364	local $ofs = $ofs - length;	498	local $ofs = $ofs - length;
365	my $mname = _dec_qname;	499	my $mname = _dec_name;
366	my $rname = _dec_qname;	500	my $rname = _dec_name;
367	($mname, $rname, unpack "NNNNN", substr $pkt, $ofs)	501	($mname, $rname, unpack "NNNNN", substr $pkt, $ofs)
368	}, # soa	502	}, # soa
369	11 => sub { ((Socket::inet_aton substr $_, 0, 4), unpack "C a*", substr $_, 4) }, # wks	503	11 => sub { ((join ".", unpack "C4", $_), unpack "C a*", substr $_, 4) }, # wks
370	12 => sub { local $ofs = $ofs - length; _dec_qname }, # ptr	504	12 => sub { local $ofs = $ofs - length; _dec_name }, # ptr
371	13 => sub { unpack "C/a C/a", $_ }, # hinfo	505	13 => sub { unpack "C/a* C/a*", $_ }, # hinfo
372	15 => sub { local $ofs = $ofs + 2 - length; ((unpack "n", $_), _dec_qname) }, # mx	506	15 => sub { local $ofs = $ofs + 2 - length; ((unpack "n", $_), _dec_name) }, # mx
373	16 => sub { unpack "(C/a)*", $_ }, # txt	507	16 => sub { unpack "(C/a)", $_ }, # txt
374	28 => sub { sprintf "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x", unpack "n8" }, # aaaa	508	28 => sub { AnyEvent::Socket::format_address ($_) }, # aaaa
375	33 => sub { local $ofs = $ofs + 6 - length; ((unpack "nnn", $_), _dec_qname) }, # srv	509	33 => sub { local $ofs = $ofs + 6 - length; ((unpack "nnn", $_), _dec_name) }, # srv
		510	35 => sub { # naptr
		511	my ($order, $preference, $flags, $service, $regexp, $offset) = unpack "nn C/a* C/a* C/a* .", $_;
		512	local $ofs = $ofs + $offset - length;
		513	($order, $preference, $flags, $service, $regexp, _dec_name)
		514	},
376	99 => sub { unpack "(C/a)*", $_ }, # spf	515	99 => sub { unpack "(C/a)", $_ }, # spf
377	);	516	);
378		517
379	sub _dec_rr {	518	sub _dec_rr {
380	my $qname = _dec_qname;	519	my $name = _dec_name;
381		520
382	my ($rt, $rc, $ttl, $rdlen) = unpack "nn N n", substr $pkt, $ofs; $ofs += 10;	521	my ($rt, $rc, $ttl, $rdlen) = unpack "nn N n", substr $pkt, $ofs; $ofs += 10;
383	local $_ = substr $pkt, $ofs, $rdlen; $ofs += $rdlen;	522	local $_ = substr $pkt, $ofs, $rdlen; $ofs += $rdlen;
384		523
385	[	524	[
386	$qname,	525	$name,
387	$type_str{$rt} \|\| $rt,	526	$type_str{$rt} \|\| $rt,
388	$class_str{$rc} \|\| $rc,	527	$class_str{$rc} \|\| $rc,
389	($dec_rr{$rt} \|\| sub { $_ })->(),	528	($dec_rr{$rt} \|\| sub { $_ })->(),
390	]	529	]
391	}	530	}
…		…
394		533
395	Unpacks a DNS packet into a perl data structure.	534	Unpacks a DNS packet into a perl data structure.
396		535
397	Examples:	536	Examples:
398		537
399	# a non-successful reply	538	# an unsuccessful reply
400	{	539	{
401	'qd' => [	540	'qd' => [
402	[ 'ruth.plan9.de.mach.uni-karlsruhe.de', '*', 'in' ]	541	[ 'ruth.plan9.de.mach.uni-karlsruhe.de', '*', 'in' ]
403	],	542	],
404	'rc' => 'nxdomain',	543	'rc' => 'nxdomain',
…		…
408	'uni-karlsruhe.de',	547	'uni-karlsruhe.de',
409	'soa',	548	'soa',
410	'in',	549	'in',
411	'netserv.rz.uni-karlsruhe.de',	550	'netserv.rz.uni-karlsruhe.de',
412	'hostmaster.rz.uni-karlsruhe.de',	551	'hostmaster.rz.uni-karlsruhe.de',
413	2008052201,	552	2008052201, 10800, 1800, 2592000, 86400
414	10800,
415	1800,
416	2592000,
417	86400
418	]	553	]
419	],	554	],
420	'tc' => '',	555	'tc' => '',
421	'ra' => 1,	556	'ra' => 1,
422	'qr' => 1,	557	'qr' => 1,
…		…
488		623
489	=back	624	=back
490		625
491	=head2 THE AnyEvent::DNS RESOLVER CLASS	626	=head2 THE AnyEvent::DNS RESOLVER CLASS
492		627
493	This is the class which deos the actual protocol work.	628	This is the class which does the actual protocol work.
494		629
495	=over 4	630	=over 4
496		631
497	=cut	632	=cut
498		633
…		…
518	our $RESOLVER;	653	our $RESOLVER;
519		654
520	sub resolver() {	655	sub resolver() {
521	$RESOLVER \|\| do {	656	$RESOLVER \|\| do {
522	$RESOLVER = new AnyEvent::DNS;	657	$RESOLVER = new AnyEvent::DNS;
523	$RESOLVER->load_resolv_conf;	658	$RESOLVER->os_config;
524	$RESOLVER	659	$RESOLVER
525	}	660	}
526	}	661	}
527		662
528	=item $resolver = new AnyEvent::DNS key => value...	663	=item $resolver = new AnyEvent::DNS key => value...
…		…
533		668
534	=over 4	669	=over 4
535		670
536	=item server => [...]	671	=item server => [...]
537		672
538	A list of server addressses (default C<v127.0.0.1>) in network format (4	673	A list of server addresses (default: C<v127.0.0.1>) in network format
539	octets for IPv4, 16 octets for IPv6 - not yet supported).	674	(i.e. as returned by C<AnyEvent::Socket::parse_address> - both IPv4 and
		675	IPv6 are supported).
540		676
541	=item timeout => [...]	677	=item timeout => [...]
542		678
543	A list of timeouts to use (also determines the number of retries). To make	679	A list of timeouts to use (also determines the number of retries). To make
544	three retries with individual time-outs of 2, 5 and 5 seconds, use C<[2,	680	three retries with individual time-outs of 2, 5 and 5 seconds, use C<[2,
…		…
553	The number of dots (default: C<1>) that a name must have so that the resolver	689	The number of dots (default: C<1>) that a name must have so that the resolver
554	tries to resolve the name without any suffixes first.	690	tries to resolve the name without any suffixes first.
555		691
556	=item max_outstanding => $integer	692	=item max_outstanding => $integer
557		693
558	Most name servers do not handle many parallel requests very well. This option	694	Most name servers do not handle many parallel requests very well. This
559	limits the numbe rof outstanding requests to C<$n> (default: C<10>), that means	695	option limits the number of outstanding requests to C<$integer>
560	if you request more than this many requests, then the additional requests will be queued	696	(default: C<10>), that means if you request more than this many requests,
561	until some other requests have been resolved.	697	then the additional requests will be queued until some other requests have
		698	been resolved.
		699
		700	=item reuse => $seconds
		701
		702	The number of seconds (default: C<300>) that a query id cannot be re-used
		703	after a timeout. If there as no time-out then query id's can be reused
		704	immediately.
562		705
563	=back	706	=back
564		707
565	=cut	708	=cut
566		709
567	sub new {	710	sub new {
568	my ($class, %arg) = @_;	711	my ($class, %arg) = @_;
569		712
		713	# try to create a ipv4 and an ipv6 socket
		714	# only fail when we cnanot create either
		715
570	socket my $fh, &Socket::AF_INET, &Socket::SOCK_DGRAM, 0	716	socket my $fh4, AF_INET , &Socket::SOCK_DGRAM, 0;
571	or Carp::croak "socket: $!";	717	socket my $fh6, AF_INET6, &Socket::SOCK_DGRAM, 0;
572		718
573	AnyEvent::Util::fh_nonblocking $fh, 1;	719	$fh4 \|\| $fh6
		720	or Carp::croak "unable to create either an IPv6 or an IPv4 socket";
574		721
575	my $self = bless {	722	my $self = bless {
576	server => [v127.0.0.1],	723	server => [],
577	timeout => [2, 5, 5],	724	timeout => [2, 5, 5],
578	search => [],	725	search => [],
579	ndots => 1,	726	ndots => 1,
580	max_outstanding => 10,	727	max_outstanding => 10,
581	reuse => 300, # reuse id's after 5 minutes only, if possible	728	reuse => 300, # reuse id's after 5 minutes only, if possible
582	%arg,	729	%arg,
583	fh => $fh,
584	reuse_q => [],	730	reuse_q => [],
585	}, $class;	731	}, $class;
586		732
587	# search should default to gethostname's domain	733	# search should default to gethostname's domain
588	# but perl lacks a good posix module	734	# but perl lacks a good posix module
589		735
590	Scalar::Util::weaken (my $wself = $self);	736	Scalar::Util::weaken (my $wself = $self);
		737
		738	if ($fh4) {
		739	AnyEvent::Util::fh_nonblocking $fh4, 1;
		740	$self->{fh4} = $fh4;
591	$self->{rw} = AnyEvent->io (fh => $fh, poll => "r", cb => sub { $wself->_recv });	741	$self->{rw4} = AnyEvent->io (fh => $fh4, poll => "r", cb => sub {
		742	if (my $peer = recv $fh4, my $pkt, MAX_PKT, 0) {
		743	$wself->_recv ($pkt, $peer);
		744	}
		745	});
		746	}
		747
		748	if ($fh6) {
		749	$self->{fh6} = $fh6;
		750	AnyEvent::Util::fh_nonblocking $fh6, 1;
		751	$self->{rw6} = AnyEvent->io (fh => $fh6, poll => "r", cb => sub {
		752	if (my $peer = recv $fh6, my $pkt, MAX_PKT, 0) {
		753	$wself->_recv ($pkt, $peer);
		754	}
		755	});
		756	}
592		757
593	$self->_compile;	758	$self->_compile;
594		759
595	$self	760	$self
596	}	761	}
597		762
598	=item $resolver->parse_resolv_conv ($string)	763	=item $resolver->parse_resolv_conv ($string)
599		764
600	Parses the given string a sif it were a F<resolv.conf> file. The following	765	Parses the given string as if it were a F<resolv.conf> file. The following
601	directives are supported:	766	directives are supported (but not necessarily implemented).
602		767
603	C<#>-style comments, C<nameserver>, C<domain>, C<search>, C<sortlist>,	768	C<#>-style comments, C<nameserver>, C<domain>, C<search>, C<sortlist>,
604	C<options> (C<timeout>, C<attempts>, C<ndots>).	769	C<options> (C<timeout>, C<attempts>, C<ndots>).
605		770
606	Everything else is silently ignored.	771	Everything else is silently ignored.
…		…
618	for (split /\n/, $resolvconf) {	783	for (split /\n/, $resolvconf) {
619	if (/^\s*#/) {	784	if (/^\s*#/) {
620	# comment	785	# comment
621	} elsif (/^\snameserver\s+(\S+)\s$/i) {	786	} elsif (/^\snameserver\s+(\S+)\s$/i) {
622	my $ip = $1;	787	my $ip = $1;
623	if (AnyEvent::Util::dotted_quad $ip) {	788	if (my $ipn = AnyEvent::Socket::parse_address ($ip)) {
624	push @{ $self->{server} }, AnyEvent::Util::socket_inet_aton $ip;	789	push @{ $self->{server} }, $ipn;
625	} else {	790	} else {
626	warn "nameserver $ip invalid and ignored\n";	791	warn "nameserver $ip invalid and ignored\n";
627	}	792	}
628	} elsif (/^\sdomain\s+(\S)\s+$/i) {	793	} elsif (/^\sdomain\s+(\S)\s+$/i) {
629	$self->{search} = [$1];	794	$self->{search} = [$1];
…		…
650	if $attempts;	815	if $attempts;
651		816
652	$self->_compile;	817	$self->_compile;
653	}	818	}
654		819
655	=item $resolver->load_resolv_conf	820	=item $resolver->os_config
656		821
657	Tries to load and parse F</etc/resolv.conf>. If there will ever be windows	822	Tries so load and parse F</etc/resolv.conf> on portable operating systems. Tries various
658	support, then this function will do the right thing under windows, too.	823	egregious hacks on windows to force the DNS servers and searchlist out of the system.
659		824
660	=cut	825	=cut
661		826
662	sub load_resolv_conf {	827	sub os_config {
663	my ($self) = @_;	828	my ($self) = @_;
664		829
		830	$self->{server} = [];
		831	$self->{search} = [];
		832
		833	if (AnyEvent::WIN32 \|\| $^O =~ /cygwin/i) {
		834	no strict 'refs';
		835
		836	# there are many options to find the current nameservers etc. on windows
		837	# all of them don't work consistently:
		838	# - the registry thing needs separate code on win32 native vs. cygwin
		839	# - the registry layout differs between windows versions
		840	# - calling windows api functions doesn't work on cygwin
		841	# - ipconfig uses locale-specific messages
		842
		843	# we use ipconfig parsing because, despite all it's brokenness,
		844	# it seems most stable in practise.
		845	# for good measure, we append a fallback nameserver to our list.
		846
		847	if (open my $fh, "ipconfig /all \|") {
		848	# parsing strategy: we go through the output and look for
		849	# :-lines with DNS in them. everything in those is regarded as
		850	# either a nameserver (if it parses as an ip address), or a suffix
		851	# (all else).
		852
		853	my $dns;
		854	while (<$fh>) {
		855	if (s/^\s.\bdns\b.://i) {
		856	$dns = 1;
		857	} elsif (/^\S/ \|\| /^\s[^:]{16,}: /) {
		858	$dns = 0;
		859	}
		860	if ($dns && /^\s(\S+)\s$/) {
		861	my $s = $1;
		862	$s =~ s/%\d+(?!\S)//; # get rid of scope id
		863	if (my $ipn = AnyEvent::Socket::parse_address ($s)) {
		864	push @{ $self->{server} }, $ipn;
		865	} else {
		866	push @{ $self->{search} }, $s;
		867	}
		868	}
		869	}
		870
		871	# always add one fallback server
		872	push @{ $self->{server} }, $DNS_FALLBACK[rand @DNS_FALLBACK];
		873
		874	$self->_compile;
		875	}
		876	} else {
		877	# try resolv.conf everywhere
		878
665	open my $fh, "</etc/resolv.conf"	879	if (open my $fh, "</etc/resolv.conf") {
666	or return;
667
668	local $/;	880	local $/;
669	$self->parse_resolv_conf (<$fh>);	881	$self->parse_resolv_conf (<$fh>);
		882	}
		883	}
		884	}
		885
		886	=item $resolver->timeout ($timeout, ...)
		887
		888	Sets the timeout values. See the C<timeout> constructor argument (and note
		889	that this method uses the values itselt, not an array-reference).
		890
		891	=cut
		892
		893	sub timeout {
		894	my ($self, @timeout) = @_;
		895
		896	$self->{timeout} = \@timeout;
		897	$self->_compile;
		898	}
		899
		900	=item $resolver->max_outstanding ($nrequests)
		901
		902	Sets the maximum number of outstanding requests to C<$nrequests>. See the
		903	C<max_outstanding> constructor argument.
		904
		905	=cut
		906
		907	sub max_outstanding {
		908	my ($self, $max) = @_;
		909
		910	$self->{max_outstanding} = $max;
		911	$self->_scheduler;
670	}	912	}
671		913
672	sub _compile {	914	sub _compile {
673	my $self = shift;	915	my $self = shift;
		916
		917	my %search; $self->{search} = [grep 0 < length, grep !$search{$_}++, @{ $self->{search} }];
		918	my %server; $self->{server} = [grep 0 < length, grep !$server{$_}++, @{ $self->{server} }];
		919
		920	unless (@{ $self->{server} }) {
		921	# use 127.0.0.1 by default, and one opendns nameserver as fallback
		922	$self->{server} = [v127.0.0.1, $DNS_FALLBACK[rand @DNS_FALLBACK]];
		923	}
674		924
675	my @retry;	925	my @retry;
676		926
677	for my $timeout (@{ $self->{timeout} }) {	927	for my $timeout (@{ $self->{timeout} }) {
678	for my $server (@{ $self->{server} }) {	928	for my $server (@{ $self->{server} }) {
…		…
696	$NOW = time;	946	$NOW = time;
697	$id->[1]->($res);	947	$id->[1]->($res);
698	}	948	}
699		949
700	sub _recv {	950	sub _recv {
701	my ($self) = @_;	951	my ($self, $pkt, $peer) = @_;
702		952
703	while (my $peer = recv $self->{fh}, my $res, 4096, 0) {	953	# we ignore errors (often one gets port unreachable, but there is
		954	# no good way to take advantage of that.
		955
704	my ($port, $host) = Socket::unpack_sockaddr_in $peer;	956	my ($port, $host) = AnyEvent::Socket::unpack_sockaddr ($peer);
705		957
706	return unless $port == 53 && grep $_ eq $host, @{ $self->{server} };	958	return unless $port == 53 && grep $_ eq $host, @{ $self->{server} };
707		959
708	$self->_feed ($res);	960	$self->_feed ($pkt);
		961	}
		962
		963	sub _free_id {
		964	my ($self, $id, $timeout) = @_;
		965
		966	if ($timeout) {
		967	# we need to block the id for a while
		968	$self->{id}{$id} = 1;
		969	push @{ $self->{reuse_q} }, [$NOW + $self->{reuse}, $id];
		970	} else {
		971	# we can quickly recycle the id
		972	delete $self->{id}{$id};
709	}	973	}
710	}
711		974
		975	--$self->{outstanding};
		976	$self->_scheduler;
		977	}
		978
		979	# execute a single request, involves sending it with timeouts to multiple servers
712	sub _exec {	980	sub _exec {
713	my ($self, $req, $retry) = @_;	981	my ($self, $req) = @_;
714		982
		983	my $retry; # of retries
		984	my $do_retry;
		985
		986	$do_retry = sub {
715	if (my $retry_cfg = $self->{retry}[$retry]) {	987	my $retry_cfg = $self->{retry}[$retry++]
		988	or do {
		989	# failure
		990	$self->_free_id ($req->[2], $retry > 1);
		991	undef $do_retry; return $req->[1]->();
		992	};
		993
716	my ($server, $timeout) = @$retry_cfg;	994	my ($server, $timeout) = @$retry_cfg;
717		995
718	$self->{id}{$req->[2]} = [AnyEvent->timer (after => $timeout, cb => sub {	996	$self->{id}{$req->[2]} = [AnyEvent->timer (after => $timeout, cb => sub {
719	$NOW = time;	997	$NOW = time;
720		998
721	# timeout, try next	999	# timeout, try next
722	$self->_exec ($req, $retry + 1);	1000	&$do_retry;
723	}), sub {	1001	}), sub {
724	my ($res) = @_;	1002	my ($res) = @_;
725		1003
726	if ($res->{tc}) {	1004	if ($res->{tc}) {
727	# success, but truncated, so use tcp	1005	# success, but truncated, so use tcp
728	AnyEvent::Util::tcp_connect +(Socket::inet_ntoa $server), 53, sub {	1006	AnyEvent::Socket::tcp_connect (AnyEvent::Socket::format_address ($server), DOMAIN_PORT, sub {
		1007	return unless $do_retry; # some other request could have invalidated us already
		1008
729	my ($fh) = @_	1009	my ($fh) = @_
730	or return $self->_exec ($req, $retry + 1);	1010	or return &$do_retry;
731		1011
732	my $handle = new AnyEvent::Handle	1012	my $handle; $handle = new AnyEvent::Handle
733	fh => $fh,	1013	fh => $fh,
		1014	timeout => $timeout,
734	on_error => sub {	1015	on_error => sub {
		1016	undef $handle;
		1017	return unless $do_retry; # some other request could have invalidated us already
735	# failure, try next	1018	# failure, try next
736	$self->_exec ($req, $retry + 1);	1019	&$do_retry;
737	};	1020	};
738		1021
739	$handle->push_write (pack "n/a", $req->[0]);	1022	$handle->push_write (pack "n/a", $req->[0]);
740	$handle->push_read_chunk (2, sub {	1023	$handle->push_read (chunk => 2, sub {
741	$handle->unshift_read_chunk ((unpack "n", $_[1]), sub {	1024	$handle->unshift_read (chunk => (unpack "n", $_[1]), sub {
		1025	undef $handle;
742	$self->_feed ($_[1]);	1026	$self->_feed ($_[1]);
743	});	1027	});
744	});	1028	});
745	shutdown $fh, 1;
746		1029
747	}, sub { $timeout };	1030	}, sub { $timeout });
748		1031
749	} else {	1032	} else {
750	# success	1033	# success
751	$self->{id}{$req->[2]} = 1;	1034	$self->_free_id ($req->[2], $retry > 1);
752	push @{ $self->{reuse_q} }, [$NOW + $self->{reuse}, $req->[2]];	1035	undef $do_retry; return $req->[1]->($res);
753	--$self->{outstanding};
754	$self->_scheduler;
755
756	$req->[1]->($res);
757	}	1036	}
758	}];	1037	}];
		1038
		1039	my $sa = AnyEvent::Socket::pack_sockaddr (DOMAIN_PORT, $server);
759		1040
760	send $self->{fh}, $req->[0], 0, Socket::pack_sockaddr_in 53, $server;	1041	my $fh = AF_INET == Socket::sockaddr_family ($sa)
761	} else {	1042	? $self->{fh4} : $self->{fh6}
762	# failure	1043	or return &$do_retry;
763	$self->{id}{$req->[2]} = 1;
764	push @{ $self->{reuse_q} }, [$NOW + $self->{reuse}, $req->[2]];
765	--$self->{outstanding};
766	$self->_scheduler;
767		1044
768	$req->[1]->();	1045	send $fh, $req->[0], 0, $sa;
769	}	1046	};
		1047
		1048	&$do_retry;
770	}	1049	}
771		1050
772	sub _scheduler {	1051	sub _scheduler {
773	my ($self) = @_;	1052	my ($self) = @_;
774		1053
		1054	no strict 'refs';
		1055
775	$NOW = time;	1056	$NOW = time;
776		1057
777	# first clear id reuse queue	1058	# first clear id reuse queue
778	delete $self->{id}{ (shift @{ $self->{reuse_q} })->[1] }	1059	delete $self->{id}{ (shift @{ $self->{reuse_q} })->[1] }
779	while @{ $self->{reuse_q} } && $self->{reuse_q}[0] <= $NOW;	1060	while @{ $self->{reuse_q} } && $self->{reuse_q}[0][0] <= $NOW;
780		1061
781	while ($self->{outstanding} < $self->{max_outstanding}) {	1062	while ($self->{outstanding} < $self->{max_outstanding}) {
782	my $req = shift @{ $self->{queue} }	1063
		1064	if (@{ $self->{reuse_q} } >= 30000) {
		1065	# we ran out of ID's, wait a bit
		1066	$self->{reuse_to} \|\|= AnyEvent->timer (after => $self->{reuse_q}[0][0] - $NOW, cb => sub {
		1067	delete $self->{reuse_to};
		1068	$self->_scheduler;
		1069	});
783	or last;	1070	last;
784
785	while () {
786	$req->[2] = int rand 65536;
787	last unless exists $self->{id}{$req->[2]};
788	}	1071	}
789		1072
		1073	if (my $req = shift @{ $self->{queue} }) {
		1074	# found a request in the queue, execute it
		1075	while () {
		1076	$req->[2] = int rand 65536;
		1077	last unless exists $self->{id}{$req->[2]};
		1078	}
		1079
		1080	++$self->{outstanding};
790	$self->{id}{$req->[2]} = 1;	1081	$self->{id}{$req->[2]} = 1;
791	substr $req->[0], 0, 2, pack "n", $req->[2];	1082	substr $req->[0], 0, 2, pack "n", $req->[2];
792		1083
793	++$self->{outstanding};
794	$self->_exec ($req, 0);	1084	$self->_exec ($req);
		1085
		1086	} elsif (my $cb = shift @{ $self->{wait} }) {
		1087	# found a wait_for_slot callback, call that one first
		1088	$cb->($self);
		1089
		1090	} else {
		1091	# nothing to do, just exit
		1092	last;
		1093	}
795	}	1094	}
796	}	1095	}
797		1096
798	=item $resolver->request ($req, $cb->($res))	1097	=item $resolver->request ($req, $cb->($res))
799		1098
…		…
811	$self->_scheduler;	1110	$self->_scheduler;
812	}	1111	}
813		1112
814	=item $resolver->resolve ($qname, $qtype, %options, $cb->($rcode, @rr))	1113	=item $resolver->resolve ($qname, $qtype, %options, $cb->($rcode, @rr))
815		1114
816	Queries the DNS for the given domain name C<$qname> of type C<$qtype> (a	1115	Queries the DNS for the given domain name C<$qname> of type C<$qtype>.
817	qtype of "*" is supported and means "any").	1116
		1117	A C<$qtype> is either a numerical query type (e.g. C<1> for A recods) or
		1118	a lowercase name (you have to look at the source to see which aliases are
		1119	supported, but all types from RFC 1035, C<aaaa>, C<srv>, C<spf> and a few
		1120	more are known to this module). A qtype of "*" is supported and means
		1121	"any" record type.
818		1122
819	The callback will be invoked with a list of matching result records or	1123	The callback will be invoked with a list of matching result records or
820	none on any error or if the name could not be found.	1124	none on any error or if the name could not be found.
821		1125
822	CNAME chains (although illegal) are followed up to a length of 8.	1126	CNAME chains (although illegal) are followed up to a length of 8.
823		1127
		1128	The callback will be invoked with an result code in string form (noerror,
		1129	formerr, servfail, nxdomain, notimp, refused and so on), or numerical
		1130	form if the result code is not supported. The remaining arguments are
		1131	arraryefs of the form C<[$name, $type, $class, @data>], where C<$name> is
		1132	the domain name, C<$type> a type string or number, C<$class> a class name
		1133	and @data is resource-record-dependent data. For C<a> records, this will
		1134	be the textual IPv4 addresses, for C<ns> or C<cname> records this will be
		1135	a domain name, for C<txt> records these are all the strings and so on.
		1136
		1137	All types mentioned in RFC 1035, C<aaaa>, C<srv> and C<spf> are
		1138	decoded. All resource records not known to this module will just return
		1139	the raw C<rdata> field as fourth entry.
		1140
824	Note that this resolver is just a stub resolver: it requires a nameserver	1141	Note that this resolver is just a stub resolver: it requires a name server
825	supporting recursive queries, will not do any recursive queries itself and	1142	supporting recursive queries, will not do any recursive queries itself and
826	is not secure when used against an untrusted name server.	1143	is not secure when used against an untrusted name server.
827		1144
828	The following options are supported:	1145	The following options are supported:
829		1146
…		…
838		1155
839	=item accept => [$type...]	1156	=item accept => [$type...]
840		1157
841	Lists the acceptable result types: only result types in this set will be	1158	Lists the acceptable result types: only result types in this set will be
842	accepted and returned. The default includes the C<$qtype> and nothing	1159	accepted and returned. The default includes the C<$qtype> and nothing
843	else.	1160	else. If this list includes C<cname>, then CNAME-chains will not be
		1161	followed (because you asked for the CNAME record).
844		1162
845	=item class => "class"	1163	=item class => "class"
846		1164
847	Specify the query class ("in" for internet, "ch" for chaosnet and "hs" for	1165	Specify the query class ("in" for internet, "ch" for chaosnet and "hs" for
848	hesiod are the only ones making sense). The default is "in", of course.	1166	hesiod are the only ones making sense). The default is "in", of course.
849		1167
850	=back	1168	=back
851		1169
852	Examples:	1170	Examples:
853		1171
854	$res->resolve ("ruth.plan9.de", "a", sub {	1172	# full example, you can paste this into perl:
855	warn Dumper [@_];	1173	use Data::Dumper;
856	});	1174	use AnyEvent::DNS;
		1175	AnyEvent::DNS::resolver->resolve (
		1176	"google.com", "*", my $cv = AnyEvent->condvar);
		1177	warn Dumper [$cv->recv];
857		1178
		1179	# shortened result:
858	[	1180	# [
		1181	# [ 'google.com', 'soa', 'in', 'ns1.google.com', 'dns-admin.google.com',
		1182	# 2008052701, 7200, 1800, 1209600, 300 ],
859	[	1183	# [
860	'ruth.schmorp.de',	1184	# 'google.com', 'txt', 'in',
861	'a',	1185	# 'v=spf1 include:_netblocks.google.com ~all'
862	'in',	1186	# ],
863	'129.13.162.95'	1187	# [ 'google.com', 'a', 'in', '64.233.187.99' ],
		1188	# [ 'google.com', 'mx', 'in', 10, 'smtp2.google.com' ],
		1189	# [ 'google.com', 'ns', 'in', 'ns2.google.com' ],
864	]	1190	# ]
		1191
		1192	# resolve a records:
		1193	$res->resolve ("ruth.plan9.de", "a", sub { warn Dumper [@_] });
		1194
		1195	# result:
		1196	# [
		1197	# [ 'ruth.schmorp.de', 'a', 'in', '129.13.162.95' ]
865	]	1198	# ]
866		1199
		1200	# resolve any records, but return only a and aaaa records:
867	$res->resolve ("test1.laendle", "*",	1201	$res->resolve ("test1.laendle", "*",
868	accept => ["a", "aaaa"],	1202	accept => ["a", "aaaa"],
869	sub {	1203	sub {
870	warn Dumper [@_];	1204	warn Dumper [@_];
871	}	1205	}
872	);	1206	);
873		1207
874	[	1208	# result:
875	[	1209	# [
876	'test1.laendle',	1210	# [ 'test1.laendle', 'a', 'in', '10.0.0.255' ],
877	'a',	1211	# [ 'test1.laendle', 'aaaa', 'in', '3ffe:1900:4545:0002:0240:0000:0000:f7e1' ]
878	'in',
879	'10.0.0.255'
880	],
881	[
882	'test1.laendle',
883	'aaaa',
884	'in',
885	'3ffe:1900:4545:0002:0240:0000:0000:f7e1'
886	]	1212	# ]
887	]
888		1213
889	=cut	1214	=cut
890		1215
891	sub resolve($%) {	1216	sub resolve($%) {
892	my $cb = pop;	1217	my $cb = pop;
…		…
905	my %atype = $opt{accept}	1230	my %atype = $opt{accept}
906	? map +($_ => 1), @{ $opt{accept} }	1231	? map +($_ => 1), @{ $opt{accept} }
907	: ($qtype => 1);	1232	: ($qtype => 1);
908		1233
909	# advance in searchlist	1234	# advance in searchlist
910	my $do_search; $do_search = sub {	1235	my ($do_search, $do_req);
		1236
		1237	$do_search = sub {
911	@search	1238	@search
912	or return $cb->();	1239	or (undef $do_search), (undef $do_req), return $cb->();
913		1240
914	(my $name = lc "$qname." . shift @search) =~ s/\.$//;	1241	(my $name = lc "$qname." . shift @search) =~ s/\.$//;
915	my $depth = 2;	1242	my $depth = 2;
916		1243
917	# advance in cname-chain	1244	# advance in cname-chain
918	my $do_req; $do_req = sub {	1245	$do_req = sub {
919	$self->request ({	1246	$self->request ({
920	rd => 1,	1247	rd => 1,
921	qd => [[$name, $qtype, $class]],	1248	qd => [[$name, $qtype, $class]],
922	}, sub {	1249	}, sub {
923	my ($res) = @_	1250	my ($res) = @_
…		…
927		1254
928	while () {	1255	while () {
929	# results found?	1256	# results found?
930	my @rr = grep $name eq lc $_->[0] && ($atype{"*"} \|\| $atype{$_->[1]}), @{ $res->{an} };	1257	my @rr = grep $name eq lc $_->[0] && ($atype{"*"} \|\| $atype{$_->[1]}), @{ $res->{an} };
931		1258
932	return $cb->(@rr)	1259	(undef $do_search), (undef $do_req), return $cb->(@rr)
933	if @rr;	1260	if @rr;
934		1261
935	# see if there is a cname we can follow	1262	# see if there is a cname we can follow
936	my @rr = grep $name eq lc $_->[0] && $_->[1] eq "cname", @{ $res->{an} };	1263	my @rr = grep $name eq lc $_->[0] && $_->[1] eq "cname", @{ $res->{an} };
937		1264
…		…
958	};	1285	};
959		1286
960	$do_search->();	1287	$do_search->();
961	}	1288	}
962		1289
		1290	=item $resolver->wait_for_slot ($cb->($resolver))
		1291
		1292	Wait until a free request slot is available and call the callback with the
		1293	resolver object.
		1294
		1295	A request slot is used each time a request is actually sent to the
		1296	nameservers: There are never more than C<max_outstanding> of them.
		1297
		1298	Although you can submit more requests (they will simply be queued until
		1299	a request slot becomes available), sometimes, usually for rate-limiting
		1300	purposes, it is useful to instead wait for a slot before generating the
		1301	request (or simply to know when the request load is low enough so one can
		1302	submit requests again).
		1303
		1304	This is what this method does: The callback will be called when submitting
		1305	a DNS request will not result in that request being queued. The callback
		1306	may or may not generate any requests in response.
		1307
		1308	Note that the callback will only be invoked when the request queue is
		1309	empty, so this does not play well if somebody else keeps the request queue
		1310	full at all times.
		1311
		1312	=cut
		1313
		1314	sub wait_for_slot {
		1315	my ($self, $cb) = @_;
		1316
		1317	push @{ $self->{wait} }, $cb;
		1318	$self->_scheduler;
		1319	}
		1320
		1321	use AnyEvent::Socket (); # circular dependency, so do not import anything and do it at the end
		1322
963	1;	1323	1;
964		1324
965	=back	1325	=back
966		1326
967	=head1 AUTHOR	1327	=head1 AUTHOR

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Comparing AnyEvent/lib/AnyEvent/DNS.pm (file contents): Revision 1.9 by root, Fri May 23 06:02:16 2008 UTC vs. Revision 1.53 by root, Fri May 30 09:40:41 2008 UTC

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Comparing AnyEvent/lib/AnyEvent/DNS.pm (file contents):
Revision 1.9 by root, Fri May 23 06:02:16 2008 UTC vs.
Revision 1.53 by root, Fri May 30 09:40:41 2008 UTC