#!/usr/bin/perl # # Copyright (C) 2004, 2007, 2009 Internet Systems Consortium, Inc. ("ISC") # Copyright (C) 2000, 2001 Internet Software Consortium. # # Permission to use, copy, modify, and/or distribute this software for any # purpose with or without fee is hereby granted, provided that the above # copyright notice and this permission notice appear in all copies. # # THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH # REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY # AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, # INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM # LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE # OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR # PERFORMANCE OF THIS SOFTWARE. # $Id: ans.pl,v 1.12 2009-11-04 02:15:30 marka Exp $ # # Ad hoc name server # use IO::File; use IO::Socket; use Net::DNS; use Net::DNS::Packet; my $sock = IO::Socket::INET->new(LocalAddr => "10.53.0.3", LocalPort => 5300, Proto => "udp") or die "$!"; my $pidf = new IO::File "ans.pid", "w" or die "cannot open pid file: $!"; print $pidf "$$\n" or die "cannot write pid file: $!"; $pidf->close or die "cannot close pid file: $!"; sub rmpid { unlink "ans.pid"; exit 1; }; $SIG{INT} = \&rmpid; $SIG{TERM} = \&rmpid; for (;;) { $sock->recv($buf, 512); print "**** request from " , $sock->peerhost, " port ", $sock->peerport, "\n"; my ($packet, $err) = new Net::DNS::Packet(\$buf, 0); $err and die $err; print "REQUEST:\n"; $packet->print; $packet->header->qr(1); $packet->header->aa(1); my @questions = $packet->question; my $qname = $questions[0]->qname; if ($qname eq "badcname.example.net") { $packet->push("answer", new Net::DNS::RR($qname . " 300 CNAME badcname.example.org")); } elsif ($qname eq "foo.baddname.example.net") { $packet->push("answer", new Net::DNS::RR("baddname.example.net" . " 300 DNAME baddname.example.org")); } elsif ($qname eq "foo.gooddname.example.net") { $packet->push("answer", new Net::DNS::RR("gooddname.example.net" . " 300 DNAME gooddname.example.org")); } elsif ($qname eq "goodcname.example.net") { $packet->push("answer", new Net::DNS::RR($qname . " 300 CNAME goodcname.example.org")); } elsif ($qname eq "cname.sub.example.org") { $packet->push("answer", new Net::DNS::RR($qname . " 300 CNAME ok.sub.example.org")); } elsif ($qname eq "ok.sub.example.org") { $packet->push("answer", new Net::DNS::RR($qname . " 300 A 192.0.2.1")); } elsif ($qname eq "www.dname.sub.example.org") { $packet->push("answer", new Net::DNS::RR("dname.sub.example.org" . " 300 DNAME ok.sub.example.org")); } elsif ($qname eq "www.ok.sub.example.org") { $packet->push("answer", new Net::DNS::RR($qname . " 300 A 192.0.2.1")); } else { $packet->push("answer", new Net::DNS::RR("www.example.com 300 A 1.2.3.4")); } $sock->send($packet->data); print "RESPONSE:\n"; $packet->print; print "\n"; }