#!/usr/bin/perl -w
#
# $Id: wcdns,v 1.5 2003/09/16 22:25:52 jmates Exp $
#
# The author disclaims all copyrights and releases this script into th
+e
# public domain.
#
# Checks whether domain(s) listed on command line (or failing that
# STDIN) are wildcard domains.
#
# Run perldoc(1) on this file for more documentation.
use strict;
# how to match Top Level Domains (TLD)
my $tld_re = qr/( \.\w+ )/x;
# domain portion option so can handle just TLD input
my $domain_re = qr/( (?:[\w-]+)? $tld_re )/x;
use Net::DNS;
my $dns = Net::DNS::Resolver->new;
$dns->defnames(0); # do not search default domain
chomp(@ARGV = <STDIN>) unless @ARGV;
for my $input (@ARGV) {
my ($domain, $tld) = $input =~ / $domain_re \W* $ /x;
# real TLD should have SOA records
unless ($dns->query($tld, 'SOA')) {
warn "notice: skipping as no SOA record: $tld\n";
next;
}
my $wildcard = '*' . $tld;
my @wc_ip = get_ip_list($dns, $wildcard);
# no wildcards for this TLD
next unless @wc_ip;
if ($domain eq $tld) {
print "tld $tld wildcard @wc_ip\n";
} else {
my @dom_ip = get_ip_list($dns, $domain);
die "error: no addresses for domain $domain\n" unless @dom_ip;
my (%union, %isect);
for my $ip (@wc_ip, @dom_ip) { $union{$ip}++ && $isect{$ip}++ }
if (keys %isect) {
print "domain $domain wildcard ", join (" ", keys %isect), "\n";
}
}
}
# Accepts Net::DNS::Resolver object and item to lookup for A records,
# returns undef or list of ip addresses
sub get_ip_list {
my $dns = shift;
my $what = shift;
my $query = $dns->query($what, 'A');
return unless $query;
my @ips;
for my $rr ($query->answer) {
push @ips, $rr->address if $rr->type eq 'A';
}
return @ips;
}
__END__
=head1 NAME
wcdns - report wildcard DNS domains
=head1 SYNOPSIS
List Top Level Domains (TLD) with wildcard records enabled.
$ wcdns .com .net .org .edu
tld .com wildcard 64.94.110.11
tld .net wildcard 64.94.110.11
Check whether host is a wildcard domain.
$ wcdns an17iqz4dhxm6es532feaxrkyidvoh7fkav.net
domain an17iqz4dhxm6es532feaxrkyidvoh7fkav.net wildcard 64.94.110.11
=head1 DESCRIPTION
=head2 Overview
Provides means to determine which TLD have wildcard DNS records, or
whether particular domains resolve to the wildcard address(es).
=head2 Normal Usage
$ wcdns domain [domain2 ...]
If no domains (top level domains, domain names, hostnames, or domainis
+h
input) are listed on the command line, the script will attempt to read
the list from standard input, which allows input from a file or pipe:
$ wcdns < domainlistfile
Output will be sent to stdout, errors to stderr. Problems will result
+in
a non-zero exit code. No news is good news; TLD or domains will only b
+e
listed if there are wildcard entries infesting the data. See
L<"SYNOPSIS"> for the two output formats; one is whether the TLD
speicifed has wildcard support; the other is whether a domain is
wildcarded.
=head1 BUGS
=head2 Reporting Bugs
Newer versions of this script may be available from:
http://sial.org/code/perl/
If the bug is in the latest version, send a report to the author.
Patches that fix problems or add new features are welcome.
=head2 Known Issues
No known issues.
=head1 TODO
More sanity checking, especially on multiple IP address results where
there is only a partial overlap between the TLD wildcard addresses and
the addresses for the domain in question.
=head1 SEE ALSO
perl(1), Net::DNS
=head1 AUTHOR
Jeremy Mates, http://sial.org/contact/
Based heavily on code posted by John Rowan Littell to the MIMEDefang
mailing list.
http://lists.roaringpenguin.com/pipermail/mimedefang/2003-September/00
+8061.html
=head1 COPYRIGHT
The author disclaims all copyrights and releases this script into the
public domain.
=head1 VERSION
$Id: wcdns,v 1.5 2003/09/16 22:25:52 jmates Exp $
=cut
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