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package Net::DNS::Resolver::cygwin;
#
# $Id: cygwin.pm 1282 2014-10-27 09:45:19Z willem $
#
use vars qw($VERSION);
$VERSION = (qw$LastChangedRevision: 1282 $)[1];
=head1 NAME
Net::DNS::Resolver::cygwin - Cygwin resolver class
=cut
use strict;
use base qw(Net::DNS::Resolver::Base);
sub getregkey {
my $key = join '/', @_;
local *LM;
open( LM, "<$key" ) or return '';
my $value = <LM>;
$value =~ s/\0+$// if $value;
close(LM);
return $value || '';
}
sub _untaint { map defined && /^(.+)$/ ? $1 : (), @_; }
sub init {
my $defaults = shift->defaults;
local *LM;
my $root = '/proc/registry/HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/Tcpip/Parameters';
unless ( -d $root ) {
# Doesn't exist, maybe we are on 95/98/Me?
$root = '/proc/registry/HKEY_LOCAL_MACHINE/SYSTEM/CurrentControlSet/Services/VxD/MSTCP';
-d $root || Carp::croak "can't read registry: $!";
}
# Best effort to find a useful domain name for the current host
# if domain ends up blank, we're probably (?) not connected anywhere
# a DNS server is interesting either...
my $domain = getregkey( $root, 'Domain' ) || getregkey( $root, 'DhcpDomain' );
# If nothing else, the searchlist should probably contain our own domain
# also see below for domain name devolution if so configured
# (also remove any duplicates later)
my $devolution = getregkey( $root, 'UseDomainNameDevolution' );
my $searchlist = getregkey( $root, 'SearchList' );
my @searchlist = _untaint $domain;
$defaults->domain(@searchlist);
push @searchlist, split m/[\s,]+/, $searchlist;
# This is (probably) adequate on NT4
my @nt4nameservers;
foreach ( grep length, getregkey( $root, 'NameServer' ), getregkey( $root, 'DhcpNameServer' ) ) {
push @nt4nameservers, split;
last;
}
# but on W2K/XP the registry layout is more advanced due to dynamically
# appearing connections. So we attempt to handle them, too...
# opt to silently fail if something isn't ok (maybe we're on NT4)
# If this doesn't fail override any NT4 style result we found, as it
# may be there but is not valid.
# drop any duplicates later
my @nameservers;
my $dnsadapters = join '/', $root, 'DNSRegisteredAdapters';
if ( opendir( LM, $dnsadapters ) ) {
my @adapters = grep !/^\.\.?$/, readdir(LM);
closedir(LM);
foreach my $adapter (@adapters) {
my $ns = getregkey( $dnsadapters, $adapter, 'DNSServerAddresses' );
until ( length($ns) < 4 ) {
push @nameservers, join '.', unpack( 'C4', $ns );
substr( $ns, 0, 4 ) = '';
}
}
}
my $interfaces = join '/', $root, 'Interfaces';
if ( opendir( LM, $interfaces ) ) {
my @ifacelist = grep !/^\.\.?$/, readdir(LM);
closedir(LM);
foreach my $iface (@ifacelist) {
my $ip = getregkey( $interfaces, $iface, 'DhcpIPAddress' )
|| getregkey( $interfaces, $iface, 'IPAddress' );
next unless $ip;
next if $ip eq '0.0.0.0';
foreach (
grep length,
getregkey( $interfaces, $iface, 'NameServer' ),
getregkey( $interfaces, $iface, 'DhcpNameServer' )
) {
push @nameservers, split;
last;
}
}
}
@nameservers = @nt4nameservers unless @nameservers;
$defaults->nameservers( _untaint @nameservers );
# fix devolution if configured, and simultaneously
# make sure no dups (but keep the order)
my @list;
my %seen;
foreach my $entry (@searchlist) {
push @list, $entry unless $seen{$entry}++;
next unless $devolution;
# as long there are more than two pieces, cut
while ( $entry =~ m#\..+\.# ) {
$entry =~ s#^[^\.]+\.(.+)$#$1#;
push @list, $entry unless $seen{$entry}++;
}
}
$defaults->searchlist( _untaint @list );
$defaults->read_env;
}
1;
__END__
=head1 SYNOPSIS
use Net::DNS::Resolver;
=head1 DESCRIPTION
This class implements the OS specific portions of C<Net::DNS::Resolver>.
No user serviceable parts inside, see L<Net::DNS::Resolver|Net::DNS::Resolver>
for all your resolving needs.
=head1 COPYRIGHT
Copyright (c)1997-2002 Michael Fuhr.
Portions Copyright (c)2002-2004 Chris Reinhardt.
All rights reserved. This program is free software; you may redistribute
it and/or modify it under the same terms as Perl itself.
=head1 SEE ALSO
L<perl>, L<Net::DNS>, L<Net::DNS::Resolver>
=cut
|
