1*00b67f09SDavid van Moolenbroek#!/usr/bin/perl 2*00b67f09SDavid van Moolenbroek# 3*00b67f09SDavid van Moolenbroek# Copyright (C) 2004, 2007, 2009, 2012 Internet Systems Consortium, Inc. ("ISC") 4*00b67f09SDavid van Moolenbroek# Copyright (C) 2000, 2001 Internet Software Consortium. 5*00b67f09SDavid van Moolenbroek# 6*00b67f09SDavid van Moolenbroek# Permission to use, copy, modify, and/or distribute this software for any 7*00b67f09SDavid van Moolenbroek# purpose with or without fee is hereby granted, provided that the above 8*00b67f09SDavid van Moolenbroek# copyright notice and this permission notice appear in all copies. 9*00b67f09SDavid van Moolenbroek# 10*00b67f09SDavid van Moolenbroek# THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 11*00b67f09SDavid van Moolenbroek# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 12*00b67f09SDavid van Moolenbroek# AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 13*00b67f09SDavid van Moolenbroek# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 14*00b67f09SDavid van Moolenbroek# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 15*00b67f09SDavid van Moolenbroek# OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 16*00b67f09SDavid van Moolenbroek# PERFORMANCE OF THIS SOFTWARE. 17*00b67f09SDavid van Moolenbroek 18*00b67f09SDavid van Moolenbroek# Id: ans.pl,v 1.12 2009/11/04 02:15:30 marka Exp 19*00b67f09SDavid van Moolenbroek 20*00b67f09SDavid van Moolenbroek# 21*00b67f09SDavid van Moolenbroek# Ad hoc name server 22*00b67f09SDavid van Moolenbroek# 23*00b67f09SDavid van Moolenbroek 24*00b67f09SDavid van Moolenbroekuse IO::File; 25*00b67f09SDavid van Moolenbroekuse IO::Socket; 26*00b67f09SDavid van Moolenbroekuse Net::DNS; 27*00b67f09SDavid van Moolenbroekuse Net::DNS::Packet; 28*00b67f09SDavid van Moolenbroek 29*00b67f09SDavid van Moolenbroekmy $sock = IO::Socket::INET->new(LocalAddr => "10.53.0.3", 30*00b67f09SDavid van Moolenbroek LocalPort => 5300, Proto => "udp") or die "$!"; 31*00b67f09SDavid van Moolenbroek 32*00b67f09SDavid van Moolenbroekmy $pidf = new IO::File "ans.pid", "w" or die "cannot open pid file: $!"; 33*00b67f09SDavid van Moolenbroekprint $pidf "$$\n" or die "cannot write pid file: $!"; 34*00b67f09SDavid van Moolenbroek$pidf->close or die "cannot close pid file: $!"; 35*00b67f09SDavid van Moolenbroeksub rmpid { unlink "ans.pid"; exit 1; }; 36*00b67f09SDavid van Moolenbroek 37*00b67f09SDavid van Moolenbroek$SIG{INT} = \&rmpid; 38*00b67f09SDavid van Moolenbroek$SIG{TERM} = \&rmpid; 39*00b67f09SDavid van Moolenbroek 40*00b67f09SDavid van Moolenbroekfor (;;) { 41*00b67f09SDavid van Moolenbroek $sock->recv($buf, 512); 42*00b67f09SDavid van Moolenbroek 43*00b67f09SDavid van Moolenbroek print "**** request from " , $sock->peerhost, " port ", $sock->peerport, "\n"; 44*00b67f09SDavid van Moolenbroek 45*00b67f09SDavid van Moolenbroek my $packet; 46*00b67f09SDavid van Moolenbroek 47*00b67f09SDavid van Moolenbroek if ($Net::DNS::VERSION > 0.68) { 48*00b67f09SDavid van Moolenbroek $packet = new Net::DNS::Packet(\$buf, 0); 49*00b67f09SDavid van Moolenbroek $@ and die $@; 50*00b67f09SDavid van Moolenbroek } else { 51*00b67f09SDavid van Moolenbroek my $err; 52*00b67f09SDavid van Moolenbroek ($packet, $err) = new Net::DNS::Packet(\$buf, 0); 53*00b67f09SDavid van Moolenbroek $err and die $err; 54*00b67f09SDavid van Moolenbroek } 55*00b67f09SDavid van Moolenbroek 56*00b67f09SDavid van Moolenbroek print "REQUEST:\n"; 57*00b67f09SDavid van Moolenbroek $packet->print; 58*00b67f09SDavid van Moolenbroek 59*00b67f09SDavid van Moolenbroek $packet->header->qr(1); 60*00b67f09SDavid van Moolenbroek $packet->header->aa(1); 61*00b67f09SDavid van Moolenbroek 62*00b67f09SDavid van Moolenbroek my @questions = $packet->question; 63*00b67f09SDavid van Moolenbroek my $qname = $questions[0]->qname; 64*00b67f09SDavid van Moolenbroek 65*00b67f09SDavid van Moolenbroek if ($qname eq "badcname.example.net") { 66*00b67f09SDavid van Moolenbroek $packet->push("answer", 67*00b67f09SDavid van Moolenbroek new Net::DNS::RR($qname . 68*00b67f09SDavid van Moolenbroek " 300 CNAME badcname.example.org")); 69*00b67f09SDavid van Moolenbroek } elsif ($qname eq "foo.baddname.example.net") { 70*00b67f09SDavid van Moolenbroek $packet->push("answer", 71*00b67f09SDavid van Moolenbroek new Net::DNS::RR("baddname.example.net" . 72*00b67f09SDavid van Moolenbroek " 300 DNAME baddname.example.org")); 73*00b67f09SDavid van Moolenbroek } elsif ($qname eq "foo.gooddname.example.net") { 74*00b67f09SDavid van Moolenbroek $packet->push("answer", 75*00b67f09SDavid van Moolenbroek new Net::DNS::RR("gooddname.example.net" . 76*00b67f09SDavid van Moolenbroek " 300 DNAME gooddname.example.org")); 77*00b67f09SDavid van Moolenbroek } elsif ($qname eq "goodcname.example.net") { 78*00b67f09SDavid van Moolenbroek $packet->push("answer", 79*00b67f09SDavid van Moolenbroek new Net::DNS::RR($qname . 80*00b67f09SDavid van Moolenbroek " 300 CNAME goodcname.example.org")); 81*00b67f09SDavid van Moolenbroek } elsif ($qname eq "cname.sub.example.org") { 82*00b67f09SDavid van Moolenbroek $packet->push("answer", 83*00b67f09SDavid van Moolenbroek new Net::DNS::RR($qname . 84*00b67f09SDavid van Moolenbroek " 300 CNAME ok.sub.example.org")); 85*00b67f09SDavid van Moolenbroek } elsif ($qname eq "ok.sub.example.org") { 86*00b67f09SDavid van Moolenbroek $packet->push("answer", 87*00b67f09SDavid van Moolenbroek new Net::DNS::RR($qname . " 300 A 192.0.2.1")); 88*00b67f09SDavid van Moolenbroek } elsif ($qname eq "www.dname.sub.example.org") { 89*00b67f09SDavid van Moolenbroek $packet->push("answer", 90*00b67f09SDavid van Moolenbroek new Net::DNS::RR("dname.sub.example.org" . 91*00b67f09SDavid van Moolenbroek " 300 DNAME ok.sub.example.org")); 92*00b67f09SDavid van Moolenbroek } elsif ($qname eq "www.ok.sub.example.org") { 93*00b67f09SDavid van Moolenbroek $packet->push("answer", 94*00b67f09SDavid van Moolenbroek new Net::DNS::RR($qname . " 300 A 192.0.2.1")); 95*00b67f09SDavid van Moolenbroek } else { 96*00b67f09SDavid van Moolenbroek $packet->push("answer", new Net::DNS::RR("www.example.com 300 A 1.2.3.4")); 97*00b67f09SDavid van Moolenbroek } 98*00b67f09SDavid van Moolenbroek 99*00b67f09SDavid van Moolenbroek $sock->send($packet->data); 100*00b67f09SDavid van Moolenbroek 101*00b67f09SDavid van Moolenbroek print "RESPONSE:\n"; 102*00b67f09SDavid van Moolenbroek $packet->print; 103*00b67f09SDavid van Moolenbroek print "\n"; 104*00b67f09SDavid van Moolenbroek} 105