| … | |
… | |
| 2 | |
2 | |
| 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 | |
8 | |
| 9 | my $cv = AnyEvent->condvar; |
9 | my $cv = AnyEvent->condvar; |
| 10 | AnyEvent::DNS::a "www.google.de", $cv; |
10 | AnyEvent::DNS::a "www.google.de", $cv; |
| 11 | # ... later |
11 | # ... later |
| 12 | my @addrs = $cv->recv; |
12 | my @addrs = $cv->recv; |
| 13 | |
13 | |
| 14 | =head1 DESCRIPTION |
14 | =head1 DESCRIPTION |
| 15 | |
15 | |
| 16 | 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 |
| 17 | as a fully asynchronous and high-performance pure-perl stub resolver. |
17 | as a fully asynchronous and high-performance pure-perl stub resolver. |
| … | |
… | |
| 35 | |
35 | |
| 36 | use AnyEvent (); |
36 | use AnyEvent (); |
| 37 | use AnyEvent::Handle (); |
37 | use AnyEvent::Handle (); |
| 38 | use AnyEvent::Util qw(AF_INET6); |
38 | use AnyEvent::Util qw(AF_INET6); |
| 39 | |
39 | |
| 40 | our $VERSION = '1.0'; |
40 | our $VERSION = 4.341; |
| 41 | |
41 | |
| 42 | our @DNS_FALLBACK = (v208.67.220.220, v208.67.222.222); |
42 | our @DNS_FALLBACK = (v208.67.220.220, v208.67.222.222); |
| 43 | |
43 | |
| 44 | =item AnyEvent::DNS::a $domain, $cb->(@addrs) |
44 | =item AnyEvent::DNS::a $domain, $cb->(@addrs) |
| 45 | |
45 | |
| … | |
… | |
| 65 | =item AnyEvent::DNS::srv $service, $proto, $domain, $cb->(@srv_rr) |
65 | =item AnyEvent::DNS::srv $service, $proto, $domain, $cb->(@srv_rr) |
| 66 | |
66 | |
| 67 | Tries to resolve the given service, protocol and domain name into a list |
67 | Tries to resolve the given service, protocol and domain name into a list |
| 68 | of service records. |
68 | of service records. |
| 69 | |
69 | |
| 70 | Each srv_rr is an array reference with the following contents: |
70 | Each C<$srv_rr> is an array reference with the following contents: |
| 71 | C<[$priority, $weight, $transport, $target]>. |
71 | C<[$priority, $weight, $transport, $target]>. |
| 72 | |
72 | |
| 73 | They will be sorted with lowest priority first, then randomly |
73 | They will be sorted with lowest priority first, then randomly |
| 74 | distributed by weight as per RFC 2782. |
74 | distributed by weight as per RFC 2782. |
| 75 | |
75 | |
| … | |
… | |
| 170 | my %pri; |
170 | my %pri; |
| 171 | push @{ $pri{$_->[3]} }, [ @$_[3,4,5,6] ] |
171 | push @{ $pri{$_->[3]} }, [ @$_[3,4,5,6] ] |
| 172 | for @_; |
172 | for @_; |
| 173 | |
173 | |
| 174 | # order by priority |
174 | # order by priority |
| 175 | for my $pri (sort { $a->[0] <=> $b->[0] } keys %pri) { |
175 | for my $pri (sort { $a <=> $b } keys %pri) { |
| 176 | # order by weight |
176 | # order by weight |
| 177 | my @rr = sort { $a->[1] <=> $b->[1] } @{ delete $pri{$pri} }; |
177 | my @rr = sort { $a->[1] <=> $b->[1] } @{ delete $pri{$pri} }; |
| 178 | |
178 | |
| 179 | my $sum; $sum += $_->[1] for @rr; |
179 | my $sum; $sum += $_->[1] for @rr; |
| 180 | |
180 | |
| … | |
… | |
| 397 | |
397 | |
| 398 | Resource records are not yet encodable. |
398 | Resource records are not yet encodable. |
| 399 | |
399 | |
| 400 | Examples: |
400 | Examples: |
| 401 | |
401 | |
| 402 | # very simple request, using lots of default values: |
402 | # very simple request, using lots of default values: |
| 403 | { rd => 1, qd => [ [ "host.domain", "a"] ] } |
403 | { rd => 1, qd => [ [ "host.domain", "a"] ] } |
| 404 | |
404 | |
| 405 | # more complex example, showing how flags etc. are named: |
405 | # more complex example, showing how flags etc. are named: |
| 406 | |
406 | |
| 407 | { |
407 | { |
| 408 | id => 10000, |
408 | id => 10000, |
| 409 | op => "query", |
409 | op => "query", |
| 410 | rc => "nxdomain", |
410 | rc => "nxdomain", |
| 411 | |
411 | |
| 412 | # flags |
412 | # flags |
| 413 | qr => 1, |
413 | qr => 1, |
| 414 | aa => 0, |
414 | aa => 0, |
| 415 | tc => 0, |
415 | tc => 0, |
| 416 | rd => 0, |
416 | rd => 0, |
| 417 | ra => 0, |
417 | ra => 0, |
| 418 | ad => 0, |
418 | ad => 0, |
| 419 | cd => 0, |
419 | cd => 0, |
| 420 | |
420 | |
| 421 | qd => [@rr], # query section |
421 | qd => [@rr], # query section |
| 422 | an => [@rr], # answer section |
422 | an => [@rr], # answer section |
| 423 | ns => [@rr], # authority section |
423 | ns => [@rr], # authority section |
| 424 | ar => [@rr], # additional records section |
424 | ar => [@rr], # additional records section |
| 425 | } |
425 | } |
| 426 | |
426 | |
| 427 | =cut |
427 | =cut |
| 428 | |
428 | |
| 429 | sub dns_pack($) { |
429 | sub dns_pack($) { |
| 430 | my ($req) = @_; |
430 | my ($req) = @_; |
| … | |
… | |
| 506 | 15 => sub { local $ofs = $ofs + 2 - length; ((unpack "n", $_), _dec_name) }, # mx |
506 | 15 => sub { local $ofs = $ofs + 2 - length; ((unpack "n", $_), _dec_name) }, # mx |
| 507 | 16 => sub { unpack "(C/a*)*", $_ }, # txt |
507 | 16 => sub { unpack "(C/a*)*", $_ }, # txt |
| 508 | 28 => sub { AnyEvent::Socket::format_address ($_) }, # aaaa |
508 | 28 => sub { AnyEvent::Socket::format_address ($_) }, # aaaa |
| 509 | 33 => sub { local $ofs = $ofs + 6 - length; ((unpack "nnn", $_), _dec_name) }, # srv |
509 | 33 => sub { local $ofs = $ofs + 6 - length; ((unpack "nnn", $_), _dec_name) }, # srv |
| 510 | 35 => sub { # naptr |
510 | 35 => sub { # naptr |
|
|
511 | # requires perl 5.10, sorry |
| 511 | my ($order, $preference, $flags, $service, $regexp, $offset) = unpack "nn C/a* C/a* C/a* .", $_; |
512 | my ($order, $preference, $flags, $service, $regexp, $offset) = unpack "nn C/a* C/a* C/a* .", $_; |
| 512 | local $ofs = $ofs + $offset - length; |
513 | local $ofs = $ofs + $offset - length; |
| 513 | ($order, $preference, $flags, $service, $regexp, _dec_name) |
514 | ($order, $preference, $flags, $service, $regexp, _dec_name) |
| 514 | }, |
515 | }, |
| 515 | 99 => sub { unpack "(C/a*)*", $_ }, # spf |
516 | 99 => sub { unpack "(C/a*)*", $_ }, # spf |
| … | |
… | |
| 533 | |
534 | |
| 534 | Unpacks a DNS packet into a perl data structure. |
535 | Unpacks a DNS packet into a perl data structure. |
| 535 | |
536 | |
| 536 | Examples: |
537 | Examples: |
| 537 | |
538 | |
| 538 | # an unsuccessful reply |
539 | # an unsuccessful reply |
| 539 | { |
540 | { |
| 540 | 'qd' => [ |
541 | 'qd' => [ |
| 541 | [ 'ruth.plan9.de.mach.uni-karlsruhe.de', '*', 'in' ] |
542 | [ 'ruth.plan9.de.mach.uni-karlsruhe.de', '*', 'in' ] |
| 542 | ], |
543 | ], |
| 543 | 'rc' => 'nxdomain', |
544 | 'rc' => 'nxdomain', |
| 544 | 'ar' => [], |
545 | 'ar' => [], |
| 545 | 'ns' => [ |
546 | 'ns' => [ |
| 546 | [ |
547 | [ |
| 547 | 'uni-karlsruhe.de', |
548 | 'uni-karlsruhe.de', |
| 548 | 'soa', |
549 | 'soa', |
| 549 | 'in', |
550 | 'in', |
| 550 | 'netserv.rz.uni-karlsruhe.de', |
551 | 'netserv.rz.uni-karlsruhe.de', |
| 551 | 'hostmaster.rz.uni-karlsruhe.de', |
552 | 'hostmaster.rz.uni-karlsruhe.de', |
| 552 | 2008052201, 10800, 1800, 2592000, 86400 |
553 | 2008052201, 10800, 1800, 2592000, 86400 |
| 553 | ] |
554 | ] |
| 554 | ], |
555 | ], |
| 555 | 'tc' => '', |
556 | 'tc' => '', |
| 556 | 'ra' => 1, |
557 | 'ra' => 1, |
| 557 | 'qr' => 1, |
558 | 'qr' => 1, |
| 558 | 'id' => 45915, |
559 | 'id' => 45915, |
| 559 | 'aa' => '', |
560 | 'aa' => '', |
| 560 | 'an' => [], |
561 | 'an' => [], |
| 561 | 'rd' => 1, |
562 | 'rd' => 1, |
| 562 | 'op' => 'query' |
563 | 'op' => 'query' |
| 563 | } |
564 | } |
| 564 | |
565 | |
| 565 | # a successful reply |
566 | # a successful reply |
| 566 | |
567 | |
| 567 | { |
568 | { |
| 568 | 'qd' => [ [ 'www.google.de', 'a', 'in' ] ], |
569 | 'qd' => [ [ 'www.google.de', 'a', 'in' ] ], |
| 569 | 'rc' => 0, |
570 | 'rc' => 0, |
| 570 | 'ar' => [ |
571 | 'ar' => [ |
| 571 | [ 'a.l.google.com', 'a', 'in', '209.85.139.9' ], |
572 | [ 'a.l.google.com', 'a', 'in', '209.85.139.9' ], |
| 572 | [ 'b.l.google.com', 'a', 'in', '64.233.179.9' ], |
573 | [ 'b.l.google.com', 'a', 'in', '64.233.179.9' ], |
| 573 | [ 'c.l.google.com', 'a', 'in', '64.233.161.9' ], |
574 | [ 'c.l.google.com', 'a', 'in', '64.233.161.9' ], |
| 574 | ], |
575 | ], |
| 575 | 'ns' => [ |
576 | 'ns' => [ |
| 576 | [ 'l.google.com', 'ns', 'in', 'a.l.google.com' ], |
577 | [ 'l.google.com', 'ns', 'in', 'a.l.google.com' ], |
| 577 | [ 'l.google.com', 'ns', 'in', 'b.l.google.com' ], |
578 | [ 'l.google.com', 'ns', 'in', 'b.l.google.com' ], |
| 578 | ], |
579 | ], |
| 579 | 'tc' => '', |
580 | 'tc' => '', |
| 580 | 'ra' => 1, |
581 | 'ra' => 1, |
| 581 | 'qr' => 1, |
582 | 'qr' => 1, |
| 582 | 'id' => 64265, |
583 | 'id' => 64265, |
| 583 | 'aa' => '', |
584 | 'aa' => '', |
| 584 | 'an' => [ |
585 | 'an' => [ |
| 585 | [ 'www.google.de', 'cname', 'in', 'www.google.com' ], |
586 | [ 'www.google.de', 'cname', 'in', 'www.google.com' ], |
| 586 | [ 'www.google.com', 'cname', 'in', 'www.l.google.com' ], |
587 | [ 'www.google.com', 'cname', 'in', 'www.l.google.com' ], |
| 587 | [ 'www.l.google.com', 'a', 'in', '66.249.93.104' ], |
588 | [ 'www.l.google.com', 'a', 'in', '66.249.93.104' ], |
| 588 | [ 'www.l.google.com', 'a', 'in', '66.249.93.147' ], |
589 | [ 'www.l.google.com', 'a', 'in', '66.249.93.147' ], |
| 589 | ], |
590 | ], |
| 590 | 'rd' => 1, |
591 | 'rd' => 1, |
| 591 | 'op' => 0 |
592 | 'op' => 0 |
| 592 | } |
593 | } |
| 593 | |
594 | |
| 594 | =cut |
595 | =cut |
| 595 | |
596 | |
| 596 | sub dns_unpack($) { |
597 | sub dns_unpack($) { |
| 597 | local $pkt = shift; |
598 | local $pkt = shift; |
| … | |
… | |
| 708 | =cut |
709 | =cut |
| 709 | |
710 | |
| 710 | sub new { |
711 | sub new { |
| 711 | my ($class, %arg) = @_; |
712 | my ($class, %arg) = @_; |
| 712 | |
713 | |
| 713 | # try to create a ipv4 and an ipv6 socket |
|
|
| 714 | # only fail when we cnanot create either |
|
|
| 715 | |
|
|
| 716 | socket my $fh4, AF_INET , &Socket::SOCK_DGRAM, 0; |
|
|
| 717 | socket my $fh6, AF_INET6, &Socket::SOCK_DGRAM, 0; |
|
|
| 718 | |
|
|
| 719 | $fh4 || $fh6 |
|
|
| 720 | or Carp::croak "unable to create either an IPv6 or an IPv4 socket"; |
|
|
| 721 | |
|
|
| 722 | my $self = bless { |
714 | my $self = bless { |
| 723 | server => [], |
715 | server => [], |
| 724 | timeout => [2, 5, 5], |
716 | timeout => [2, 5, 5], |
| 725 | search => [], |
717 | search => [], |
| 726 | ndots => 1, |
718 | ndots => 1, |
| … | |
… | |
| 731 | }, $class; |
723 | }, $class; |
| 732 | |
724 | |
| 733 | # search should default to gethostname's domain |
725 | # search should default to gethostname's domain |
| 734 | # but perl lacks a good posix module |
726 | # but perl lacks a good posix module |
| 735 | |
727 | |
|
|
728 | # try to create an ipv4 and an ipv6 socket |
|
|
729 | # only fail when we cannot create either |
|
|
730 | my $got_socket; |
|
|
731 | |
| 736 | Scalar::Util::weaken (my $wself = $self); |
732 | Scalar::Util::weaken (my $wself = $self); |
| 737 | |
733 | |
| 738 | if ($fh4) { |
734 | if (socket my $fh4, AF_INET , &Socket::SOCK_DGRAM, 0) { |
|
|
735 | ++$got_socket; |
|
|
736 | |
| 739 | AnyEvent::Util::fh_nonblocking $fh4, 1; |
737 | AnyEvent::Util::fh_nonblocking $fh4, 1; |
| 740 | $self->{fh4} = $fh4; |
738 | $self->{fh4} = $fh4; |
| 741 | $self->{rw4} = AnyEvent->io (fh => $fh4, poll => "r", cb => sub { |
739 | $self->{rw4} = AnyEvent->io (fh => $fh4, poll => "r", cb => sub { |
| 742 | if (my $peer = recv $fh4, my $pkt, MAX_PKT, 0) { |
740 | if (my $peer = recv $fh4, my $pkt, MAX_PKT, 0) { |
| 743 | $wself->_recv ($pkt, $peer); |
741 | $wself->_recv ($pkt, $peer); |
| 744 | } |
742 | } |
| 745 | }); |
743 | }); |
| 746 | } |
744 | } |
| 747 | |
745 | |
| 748 | if ($fh6) { |
746 | if (AF_INET6 && socket my $fh6, AF_INET6, &Socket::SOCK_DGRAM, 0) { |
|
|
747 | ++$got_socket; |
|
|
748 | |
| 749 | $self->{fh6} = $fh6; |
749 | $self->{fh6} = $fh6; |
| 750 | AnyEvent::Util::fh_nonblocking $fh6, 1; |
750 | AnyEvent::Util::fh_nonblocking $fh6, 1; |
| 751 | $self->{rw6} = AnyEvent->io (fh => $fh6, poll => "r", cb => sub { |
751 | $self->{rw6} = AnyEvent->io (fh => $fh6, poll => "r", cb => sub { |
| 752 | if (my $peer = recv $fh6, my $pkt, MAX_PKT, 0) { |
752 | if (my $peer = recv $fh6, my $pkt, MAX_PKT, 0) { |
| 753 | $wself->_recv ($pkt, $peer); |
753 | $wself->_recv ($pkt, $peer); |
| 754 | } |
754 | } |
| 755 | }); |
755 | }); |
| 756 | } |
756 | } |
|
|
757 | |
|
|
758 | $got_socket |
|
|
759 | or Carp::croak "unable to create either an IPv4 or an IPv6 socket"; |
| 757 | |
760 | |
| 758 | $self->_compile; |
761 | $self->_compile; |
| 759 | |
762 | |
| 760 | $self |
763 | $self |
| 761 | } |
764 | } |
| … | |
… | |
| 995 | |
998 | |
| 996 | $self->{id}{$req->[2]} = [AnyEvent->timer (after => $timeout, cb => sub { |
999 | $self->{id}{$req->[2]} = [AnyEvent->timer (after => $timeout, cb => sub { |
| 997 | $NOW = time; |
1000 | $NOW = time; |
| 998 | |
1001 | |
| 999 | # timeout, try next |
1002 | # timeout, try next |
| 1000 | &$do_retry; |
1003 | &$do_retry if $do_retry; |
| 1001 | }), sub { |
1004 | }), sub { |
| 1002 | my ($res) = @_; |
1005 | my ($res) = @_; |
| 1003 | |
1006 | |
| 1004 | if ($res->{tc}) { |
1007 | if ($res->{tc}) { |
| 1005 | # success, but truncated, so use tcp |
1008 | # success, but truncated, so use tcp |
| … | |
… | |
| 1113 | |
1116 | |
| 1114 | push @{ $self->{queue} }, [dns_pack $req, $cb]; |
1117 | push @{ $self->{queue} }, [dns_pack $req, $cb]; |
| 1115 | $self->_scheduler; |
1118 | $self->_scheduler; |
| 1116 | } |
1119 | } |
| 1117 | |
1120 | |
| 1118 | =item $resolver->resolve ($qname, $qtype, %options, $cb->($rcode, @rr)) |
1121 | =item $resolver->resolve ($qname, $qtype, %options, $cb->(@rr)) |
| 1119 | |
1122 | |
| 1120 | Queries the DNS for the given domain name C<$qname> of type C<$qtype>. |
1123 | Queries the DNS for the given domain name C<$qname> of type C<$qtype>. |
| 1121 | |
1124 | |
| 1122 | A C<$qtype> is either a numerical query type (e.g. C<1> for A records) or |
1125 | A C<$qtype> is either a numerical query type (e.g. C<1> for A records) or |
| 1123 | a lowercase name (you have to look at the source to see which aliases are |
1126 | a lowercase name (you have to look at the source to see which aliases are |
| … | |
… | |
| 1126 | "any" record type. |
1129 | "any" record type. |
| 1127 | |
1130 | |
| 1128 | The callback will be invoked with a list of matching result records or |
1131 | The callback will be invoked with a list of matching result records or |
| 1129 | none on any error or if the name could not be found. |
1132 | none on any error or if the name could not be found. |
| 1130 | |
1133 | |
| 1131 | CNAME chains (although illegal) are followed up to a length of 8. |
1134 | CNAME chains (although illegal) are followed up to a length of 10. |
| 1132 | |
1135 | |
| 1133 | The callback will be invoked with an result code in string form (noerror, |
1136 | The callback will be invoked with arraryefs of the form C<[$name, $type, |
| 1134 | formerr, servfail, nxdomain, notimp, refused and so on), or numerical |
1137 | $class, @data>], where C<$name> is the domain name, C<$type> a type string |
| 1135 | form if the result code is not supported. The remaining arguments are |
1138 | or number, C<$class> a class name and @data is resource-record-dependent |
| 1136 | arraryefs of the form C<[$name, $type, $class, @data>], where C<$name> is |
1139 | data. For C<a> records, this will be the textual IPv4 addresses, for C<ns> |
| 1137 | the domain name, C<$type> a type string or number, C<$class> a class name |
1140 | or C<cname> records this will be a domain name, for C<txt> records these |
| 1138 | and @data is resource-record-dependent data. For C<a> records, this will |
1141 | are all the strings and so on. |
| 1139 | be the textual IPv4 addresses, for C<ns> or C<cname> records this will be |
|
|
| 1140 | a domain name, for C<txt> records these are all the strings and so on. |
|
|
| 1141 | |
1142 | |
| 1142 | All types mentioned in RFC 1035, C<aaaa>, C<srv>, C<naptr> and C<spf> are |
1143 | All types mentioned in RFC 1035, C<aaaa>, C<srv>, C<naptr> and C<spf> are |
| 1143 | decoded. All resource records not known to this module will have |
1144 | decoded. All resource records not known to this module will have |
| 1144 | the raw C<rdata> field as fourth entry. |
1145 | the raw C<rdata> field as fourth entry. |
| 1145 | |
1146 | |
| … | |
… | |
| 1243 | $do_search = sub { |
1244 | $do_search = sub { |
| 1244 | @search |
1245 | @search |
| 1245 | or (undef $do_search), (undef $do_req), return $cb->(); |
1246 | or (undef $do_search), (undef $do_req), return $cb->(); |
| 1246 | |
1247 | |
| 1247 | (my $name = lc "$qname." . shift @search) =~ s/\.$//; |
1248 | (my $name = lc "$qname." . shift @search) =~ s/\.$//; |
| 1248 | my $depth = 2; |
1249 | my $depth = 10; |
| 1249 | |
1250 | |
| 1250 | # advance in cname-chain |
1251 | # advance in cname-chain |
| 1251 | $do_req = sub { |
1252 | $do_req = sub { |
| 1252 | $self->request ({ |
1253 | $self->request ({ |
| 1253 | rd => 1, |
1254 | rd => 1, |
| … | |
… | |
| 1330 | |
1331 | |
| 1331 | =back |
1332 | =back |
| 1332 | |
1333 | |
| 1333 | =head1 AUTHOR |
1334 | =head1 AUTHOR |
| 1334 | |
1335 | |
| 1335 | Marc Lehmann <schmorp@schmorp.de> |
1336 | Marc Lehmann <schmorp@schmorp.de> |
| 1336 | http://home.schmorp.de/ |
1337 | http://home.schmorp.de/ |
| 1337 | |
1338 | |
| 1338 | =cut |
1339 | =cut |
| 1339 | |
1340 | |
