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Diffstat (limited to 'bin/tests/system/digdelv/ans5/ans.pl')
| -rw-r--r-- | bin/tests/system/digdelv/ans5/ans.pl | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/bin/tests/system/digdelv/ans5/ans.pl b/bin/tests/system/digdelv/ans5/ans.pl new file mode 100644 index 0000000..6396406 --- /dev/null +++ b/bin/tests/system/digdelv/ans5/ans.pl @@ -0,0 +1,176 @@ +#!/usr/bin/perl + +# Copyright (C) Internet Systems Consortium, Inc. ("ISC") +# +# SPDX-License-Identifier: MPL-2.0 +# +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, you can obtain one at https://mozilla.org/MPL/2.0/. +# +# See the COPYRIGHT file distributed with this work for additional +# information regarding copyright ownership. + +# This is a TCP-only DNS server whose aim is to facilitate testing how dig +# copes with prematurely closed TCP connections. +# +# This server can be configured (through a separate control socket) with a +# series of responses to send for subsequent incoming TCP DNS queries. Only +# one query is handled before closing each connection. In order to keep things +# simple, the server is not equipped with any mechanism for handling malformed +# queries. +# +# Available response types are defined in the %response_types hash in the +# getAnswerSection() function below. Each RR returned is generated dynamically +# based on the QNAME found in the incoming query. + +use IO::File; +use Net::DNS; +use Net::DNS::Packet; + +use strict; + +# Ignore SIGPIPE so we won't fail if peer closes a TCP socket early +local $SIG{PIPE} = 'IGNORE'; + +# Flush logged output after every line +local $| = 1; + +my $server_addr = "10.53.0.5"; +if (@ARGV > 0) { + $server_addr = @ARGV[0]; +} + +my $mainport = int($ENV{'PORT'}); +if (!$mainport) { $mainport = 5300; } +my $ctrlport = int($ENV{'EXTRAPORT1'}); +if (!$ctrlport) { $ctrlport = 5301; } + +my $ctlsock = IO::Socket::INET->new(LocalAddr => "$server_addr", + LocalPort => $ctrlport, Proto => "tcp", Listen => 5, Reuse => 1) or die "$!"; + +my $tcpsock = IO::Socket::INET->new(LocalAddr => "$server_addr", + LocalPort => $mainport, Proto => "tcp", Listen => 5, Reuse => 1) or die "$!"; + +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; + +my @response_sequence = ("complete_axfr"); +my $connection_counter = 0; + +# Return the next answer type to send, incrementing the connection counter and +# making sure the latter does not exceed the size of the array holding the +# configured response sequence. +sub getNextResponseType { + my $response_type = $response_sequence[$connection_counter]; + + $connection_counter++; + $connection_counter %= scalar(@response_sequence); + + return $response_type; +} + +# Return an array of resource records comprising the answer section of a given +# response type. +sub getAnswerSection { + my ($response_type, $qname) = @_; + + my %response_types = ( + no_response => [], + + partial_axfr => [ + Net::DNS::RR->new("$qname 300 IN SOA . . 0 0 0 0 300"), + Net::DNS::RR->new("$qname NS ."), + ], + + complete_axfr => [ + Net::DNS::RR->new("$qname 300 IN SOA . . 0 0 0 0 300"), + Net::DNS::RR->new("$qname NS ."), + Net::DNS::RR->new("$qname 300 IN SOA . . 0 0 0 0 300"), + ], + ); + + return $response_types{$response_type}; +} + + +# Generate a Net::DNS::Packet containing the response to send on the current +# TCP connection. If the answer section of the response is determined to be +# empty, no data will be sent on the connection at all (immediate EOF). +sub generateResponse { + my ($buf) = @_; + my $request; + + if ($Net::DNS::VERSION > 0.68) { + $request = new Net::DNS::Packet(\$buf, 0); + $@ and die $@; + } else { + my $err; + ($request, $err) = new Net::DNS::Packet(\$buf, 0); + $err and die $err; + } + + my @questions = $request->question; + my $qname = $questions[0]->qname; + my $qtype = $questions[0]->qtype; + my $qclass = $questions[0]->qclass; + my $id = $request->header->id; + + my $packet = new Net::DNS::Packet($qname, $qtype, $qclass); + $packet->header->qr(1); + $packet->header->aa(1); + $packet->header->id($id); + + my $response_type = getNextResponseType(); + my $answers = getAnswerSection($response_type, $qname); + for my $rr (@$answers) { + $packet->push("answer", $rr); + } + + print " Sending \"$response_type\" response\n"; + + return $packet->data if @$answers; +} + +my $rin; +my $rout; +for (;;) { + $rin = ''; + vec($rin, fileno($ctlsock), 1) = 1; + vec($rin, fileno($tcpsock), 1) = 1; + + select($rout = $rin, undef, undef, undef); + + if (vec($rout, fileno($ctlsock), 1)) { + my $conn = $ctlsock->accept; + @response_sequence = split(' ', $conn->getline); + $connection_counter = 0; + print "Response sequence set to: @response_sequence\n"; + $conn->close; + } elsif (vec($rout, fileno($tcpsock), 1)) { + my $buf; + my $lenbuf; + my $conn = $tcpsock->accept; + my $n = $conn->sysread($lenbuf, 2); + die unless $n == 2; + my $len = unpack("n", $lenbuf); + $n = $conn->sysread($buf, $len); + die unless $n == $len; + print "TCP request\n"; + my $response = generateResponse($buf); + if ($response) { + $len = length($response); + $n = $conn->syswrite(pack("n", $len), 2); + $n = $conn->syswrite($response, $len); + print " Sent: $n chars via TCP\n"; + } else { + print " No response sent\n"; + } + $conn->close; + } +} |