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