File Coverage

blib/lib/POE/Component/Client/DNS/Recursive.pm

Criterion	Covered	Total	%
statement	193	257	75.1
branch	45	78	57.6
condition	12	25	48.0
subroutine	21	22	95.4
pod	1	1	100.0
total	272	383	71.0

package POE::Component::Client::DNS::Recursive;
$POE::Component::Client::DNS::Recursive::VERSION = '1.10';
#ABSTRACT: A recursive DNS client for POE

use strict;
use warnings;
use Carp;
use Socket qw[:all];
use Net::IP::Minimal qw(:PROC);
use IO::Socket::IP;
use POE qw(NFA);
use Net::DNS::Packet;

my @hc_hints = qw(
198.41.0.4
192.228.79.201
192.33.4.12
128.8.10.90
192.203.230.10
192.5.5.241
192.112.36.4
128.63.2.53
192.36.148.17
);

sub resolve {
  my $package = shift;
  my %opts = @_;
  $opts{lc $_} = delete $opts{$_} for keys %opts;
  croak "$package requires a 'host' argument\n"
	unless $opts{host};
  croak "$package requires an 'event' argument\n"
	unless $opts{event};
  $opts{nameservers} = [ ] unless $opts{nameservers} and ref $opts{nameservers} eq 'ARRAY';
  @{ $opts{nameservers} } = grep { ip_get_version( $_ ) } @{ $opts{nameservers} };
  my $options = delete $opts{options};
  my $self = bless \%opts, $package;
  my $sender = $poe_kernel->get_active_session();
  $self->{_sender} = $sender;
  POE::NFA->spawn(
  object_states => {
    initial => [
	$self => { setup => '_start' },
	$self => [qw(_default)],
    ],
    hints   => [
	$self => {
	_init  => '_hints_go',
        _setup => '_send',
        _read  => '_hints',
        _timeout => '_hints_timeout',
	},
    ],
    query   => [
	$self => {
        _setup => '_send',
        _read  => '_query',
        _timeout => '_query_timeout',
	},
    ],
    done    => [
        $self => [qw(_close _error)],
    ],
  },
  runstate => $self,
  )->goto_state( 'initial' => 'setup' );
  return $self;
}

sub _default {
  return 0;
}

sub _start {
  my ($kernel,$machine,$runstate) = @_[KERNEL,MACHINE,RUNSTATE];
  my $sender = $runstate->{_sender};
  if ( $kernel == $sender and !$runstate->{session} ) {
	croak "Not called from another POE session and 'session' wasn't set\n";
  }
  my $sender_id;
  if ( $runstate->{session} ) {
    if ( my $ref = $kernel->alias_resolve( $runstate->{session} ) ) {
	$sender_id = $ref->ID();
    }
    else {
	croak "Could not resolve 'session' to a valid POE session\n";
    }
  }
  else {
    $sender_id = $sender->ID();
  }
  $kernel->refcount_increment( $sender_id, __PACKAGE__ )
     unless ref $runstate->{event} eq 'POE::Session::AnonEvent';
  $kernel->detach_myself();
  $runstate->{sender_id} = $sender_id;
  my $type = $runstate->{type} || ( ip_get_version( $runstate->{host} ) ? 'PTR' : 'A' );
  my $class = $runstate->{class} || 'IN';
  $runstate->{qstack} = [ ];
  $runstate->{current} = {
        query => $runstate->{host},
        type  => $type,
        packet => Net::DNS::Packet->new($runstate->{host},$type,$class),
  };
  $runstate->{socket} = IO::Socket::IP->new( Proto => 'udp' );
  $machine->goto_state( 'hints', '_init' );
  return;
}

sub _hints_go {
  my ($kernel,$machine,$runstate) = @_[KERNEL,MACHINE,RUNSTATE];
  my $hints;
  if ( scalar @{ $runstate->{nameservers} } ) {
     $hints = $runstate->{nameservers};
  }
  else {
     $hints = [ @hc_hints ];
  }
  $runstate->{_hints} = $hints;
  $machine->goto_state( 'hints', '_setup', Net::DNS::Packet->new('.','NS','IN'), splice( @$hints, rand($#{$hints}), 1) );
  return;
}

sub _send {
  my ($machine,$runstate,$state,$packet,$ns) = @_[MACHINE,RUNSTATE,STATE,ARG0,ARG1];
  my $socket = $runstate->{socket};
  my $data = $packet->data;
  my $ai;
  {
    my %hints = (flags => AI_NUMERICHOST, socktype => SOCK_DGRAM, protocol => IPPROTO_UDP);
    my ($err, @res) = getaddrinfo($ns, '53', \%hints);
    if ( $err ) {
      warn "'$ns' didn't produce an valid server address\n";
      $machine->goto_state( 'done', '_error', $err );
      return;
    }
    $ai = shift @res;
  }
  $socket->socket( $ai->{family}, $ai->{socktype}, $ai->{protocol} );
  unless ( send( $socket, $data, 0, $ai->{addr} ) == length($data) ) {
     $machine->goto_state( 'done', '_error', "$ns: $!" );
     return;
  }
  $poe_kernel->select_read( $socket, '_read' );
  $poe_kernel->delay( '_timeout', $runstate->{timeout} || 5 );
  return;
}

sub _hints {
  my ($machine,$runstate,$socket) = @_[MACHINE,RUNSTATE,ARG0];
  $poe_kernel->delay( '_timeout' );
  my $packet = _read_socket( $socket );
    my %hints;
    if (my @ans = $packet->answer) {
      foreach my $rr (@ans) {
        if ($rr->name =~ /^\.?$/ and
            $rr->type eq "NS") {
          # Found root authority
          my $server = lc $rr->rdatastr;
          $server =~ s/\.$//;
          $hints{$server} = [];
        }
      }
      foreach my $rr ($packet->additional) {
        if (my $server = lc $rr->name){
          if ( $rr->type eq "A") {
            if ($hints{$server}) {
              push @{ $hints{$server} }, $rr->rdatastr;
            }
          }
        }
      }
    }
  if ( $runstate->{trace} ) {
    if ( ref $runstate->{trace} eq 'POE::Session::AnonEvent' ) {
       $runstate->{trace}->( $packet );
    }
    else {
       $poe_kernel->post( $runstate->{sender_id}, $runstate->{trace}, $packet );
    }
  }
  $runstate->{hints} = \%hints;
  my @ns = _ns_from_cache( $runstate->{hints} );
  unless ( scalar @ns ) {
     $machine->goto_state( 'hints', '_init' );
     return;
  }
  my $query = $runstate->{current};
  $query->{servers} = \@ns;
  my ($nameserver) = splice @ns, rand($#ns), 1;
  $machine->goto_state( 'query', '_setup', $query->{packet}, $nameserver );
  return;
}

sub _hints_timeout {
  my ($machine,$runstate) = @_[MACHINE,RUNSTATE];
  my $hints = $runstate->{_hints};
  if ( scalar @{ $hints } ) {
     $machine->goto_state( 'hints', '_setup', Net::DNS::Packet->new('.','NS','IN'), splice( @$hints, rand($#{$hints}), 1) );
  }
  elsif ( defined $runstate->{nameservers} ) {
     $machine->goto_state( 'hints', '_init' );
     return;
  }
  else {
     $machine->goto_state( 'done', '_error', 'Ran out of authority records' );
  }
  return;
}

sub _query {
  my ($machine,$runstate,$socket) = @_[MACHINE,RUNSTATE,ARG0];
  $poe_kernel->delay( '_timeout' );
  my $packet = _read_socket( $socket );
  my @ns;
  my $status = $packet->header->rcode;
  if ( $status ne 'NOERROR' ) {
	$machine->goto_state( 'done', '_error', $status );
        return;
  }
  if (my @ans = $packet->answer) {
     # This is the end of the chain.
     unless ( scalar @{ $runstate->{qstack} } ) {
	$machine->goto_state( 'done', '_close', $packet );
        return;
     }
     # Okay we have queries pending.
     push @ns, $_->rdatastr for grep { $_->type eq 'A' } @ans;
     $runstate->{current} = pop @{ $runstate->{qstack} };
  }
  else {
     if ( $runstate->{trace} ) {
        $poe_kernel->post( $runstate->{sender_id}, $runstate->{trace}, $packet );
     }
     my $authority = _authority( $packet );
     @ns = _ns_from_cache( $authority );
     unless ( scalar @ns ) {
        $runstate->{current}->{authority} = $authority;
        push @{ $runstate->{qstack} }, $runstate->{current};
        my $host = ( keys %{ $authority } )[rand scalar keys %{ $authority }];
        delete $authority->{$host};
        $runstate->{current} = {
           query => $host,
           type  => 'A',
           packet => Net::DNS::Packet->new($host,'A','IN'),
        };
        @ns = _ns_from_cache( $runstate->{hints} );
     }
  }
  my $query = $runstate->{current};
  $query->{servers} = \@ns;
  my ($nameserver) = splice @ns, rand($#ns), 1;
  $poe_kernel->yield( '_setup', $query->{packet}, $nameserver );
  return;
}

sub _query_timeout {
  my ($machine,$runstate) = @_[MACHINE,RUNSTATE];
  my $query = $runstate->{current};
  my $servers = $query->{servers};
  my ($nameserver) = splice @{ $servers }, rand($#{ $servers }), 1;
  # actually check here if there is something on the stack.
  # pop off the most recent, and get the next authority record
  # push back on to the stack and do a lookup for the authority
  # record. No authority records left, then complain and bailout.
  unless ( $nameserver ) {
    if ( scalar @{ $runstate->{qstack} } ) {
        $runstate->{current} = pop @{ $runstate->{qstack} };
        my $host = ( keys %{ $runstate->{current}->{authority} } )[rand scalar keys %{ $runstate->{current}->{authority} }];
        unless ( $host ) { # Oops
           $machine->goto_state( 'done', '_error', 'Ran out of authority records' );
           return; # OMG
	}
        delete $runstate->{current}->{authority}->{ $host };
        push @{ $runstate->{qstack} }, $runstate->{current};
        $runstate->{current} = {
           query => $host,
           type  => 'A',
           packet => Net::DNS::Packet->new($host,'A','IN'),
        };
        my @ns = _ns_from_cache( $runstate->{hints} );
        $runstate->{current}->{servers} = \@ns;
        ($nameserver) = splice @ns, rand($#ns), 1;
    }
    else {
        $machine->goto_state( 'done', '_error', 'Ran out of authority records' );
        return; # OMG
    }
  }
  unless ( $nameserver ) {  # SERVFAIL? maybe
    $machine->goto_state( 'done', '_error', 'Ran out of nameservers to query' );
    return;
  }
  $poe_kernel->yield( '_setup', $query->{packet}, $nameserver );
  return;
}

sub _error {
  my ($kernel,$machine,$runstate,$error) = @_[KERNEL,MACHINE,RUNSTATE,ARG0];
  $kernel->select_read( $runstate->{socket} ); # Just in case
  my $resp = {};
  $resp->{$_} = $runstate->{$_} for qw(host type class context);
  $resp->{response} = undef;
  $resp->{error} = $error;
  delete $runstate->{trace};
  if ( ref $runstate->{event} eq 'POE::Session::AnonEvent' ) {
     my $postback = delete $runstate->{event};
     $postback->( $resp );
  }
  else {
     $kernel->post( $runstate->{sender_id}, $runstate->{event}, $resp );
     $kernel->refcount_decrement( $runstate->{sender_id}, __PACKAGE__ );
  }
  return;
}

sub _close {
  my ($kernel,$machine,$runstate,$packet) = @_[KERNEL,MACHINE,RUNSTATE,ARG0];
  $kernel->select_read( $runstate->{socket} ); # Just in case
  my $resp = {};
  $resp->{$_} = $runstate->{$_} for qw(host type class context);
  $resp->{response} = $packet;
  delete $runstate->{trace};
  if ( ref $runstate->{event} eq 'POE::Session::AnonEvent' ) {
     my $postback = delete $runstate->{event};
     $postback->( $resp );
  }
  else {
     $kernel->post( $runstate->{sender_id}, $runstate->{event}, $resp );
     $kernel->refcount_decrement( $runstate->{sender_id}, __PACKAGE__ );
  }
  return;
}

sub _authority {
  my $packet = shift || return;
    my %hints;
    if (my @ans = $packet->authority) {
      foreach my $rr (@ans) {
            if ( $rr->type eq 'NS') {
          # Found root authority
          my $server = lc $rr->rdatastr;
          $server =~ s/\.$//;
          $hints{$server} = [];
        }
      }
      foreach my $rr ($packet->additional) {
        if (my $server = lc $rr->name){
              push @{ $hints{$server} }, $rr->rdatastr if $rr->type eq 'A' and $hints{$server};
        }
      }
    }
  return \%hints;
}

sub _read_socket {
  my $socket = shift || return;
  $poe_kernel->select_read( $socket );
  my $message;
  unless ( $socket->recv( $message, 512 ) ) {
     warn "$!\n";
     return;
  }
  my ($in, $len) = Net::DNS::Packet->new( \$message, 0 );
  if ( $@ ) {
     warn "$@\n";
     return;
  }
  unless ( $len ) {
     warn "Bad size\n";
     return;
  }
  return $in;
}

sub _ns_from_cache {
  my $hashref = shift || return;
  my @ns;
  foreach my $ns (keys %{ $hashref }) {
    push @ns, @{ $hashref->{$ns} } if scalar @{ $hashref->{$ns} };
  }
  return @ns;
}

'Recursive lookup, recursive lookup, recursive lookup ....';

__END__