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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:59:48 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 15:59:48 +0000 |
commit | 3b9b6d0b8e7f798023c9d109c490449d528fde80 (patch) | |
tree | 2e1c188dd7b8d7475cd163de9ae02c428343669b /bin/tests/system/reclimit/ans2/ans.pl | |
parent | Initial commit. (diff) | |
download | bind9-0cd617f6bad00b68e380aeb0024ef4dc1985191c.tar.xz bind9-0cd617f6bad00b68e380aeb0024ef4dc1985191c.zip |
Adding upstream version 1:9.18.19.upstream/1%9.18.19upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | bin/tests/system/reclimit/ans2/ans.pl | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/bin/tests/system/reclimit/ans2/ans.pl b/bin/tests/system/reclimit/ans2/ans.pl new file mode 100644 index 0000000..4576951 --- /dev/null +++ b/bin/tests/system/reclimit/ans2/ans.pl @@ -0,0 +1,235 @@ +#!/usr/bin/env 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. + +use strict; +use warnings; + +use IO::File; +use IO::Socket; +use Net::DNS; + +my $localaddr = "10.53.0.2"; +my $limit = getlimit(); +my $no_more_waiting = 0; +my @delayed_response; +my $timeout; + +my $localport = int($ENV{'PORT'}); +if (!$localport) { $localport = 5300; } + +my $udpsock = IO::Socket::INET->new(LocalAddr => "$localaddr", + LocalPort => $localport, Proto => "udp", Reuse => 1) or die "$!"; + +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 $count = 0; +my $send_response = 0; + +sub getlimit { + if ( -e "ans.limit") { + open(FH, "<", "ans.limit"); + my $line = <FH>; + chomp $line; + close FH; + if ($line =~ /^\d+$/) { + return $line; + } + } + + return 0; +} + +# If $wait == 0 is returned, returned reply will be sent immediately. +# If $wait == 1 is returned, sending the returned reply might be delayed; see +# comments inside handle_UDP() for details. +sub reply_handler { + my ($qname, $qclass, $qtype) = @_; + my ($rcode, @ans, @auth, @add, $wait); + + print ("request: $qname/$qtype\n"); + STDOUT->flush(); + + $wait = 0; + $count += 1; + + if ($qname eq "count" ) { + if ($qtype eq "TXT") { + my ($ttl, $rdata) = (0, "$count"); + my $rr = new Net::DNS::RR("$qname $ttl $qclass $qtype $rdata"); + push @ans, $rr; + print ("\tcount: $count\n"); + } + $rcode = "NOERROR"; + } elsif ($qname eq "reset" ) { + $count = 0; + $send_response = 0; + $limit = getlimit(); + $rcode = "NOERROR"; + print ("\tlimit: $limit\n"); + } elsif ($qname eq "direct.example.org" ) { + if ($qtype eq "A") { + my ($ttl, $rdata) = (3600, $localaddr); + my $rr = new Net::DNS::RR("$qname $ttl $qclass $qtype $rdata"); + push @ans, $rr; + } + $rcode = "NOERROR"; + } elsif ($qname eq "indirect1.example.org" || + $qname eq "indirect2.example.org" || + $qname eq "indirect3.example.org" || + $qname eq "indirect4.example.org" || + $qname eq "indirect5.example.org" || + $qname eq "indirect6.example.org" || + $qname eq "indirect7.example.org" || + $qname eq "indirect8.example.org") { + if (! $send_response) { + my $rr = new Net::DNS::RR("$qname 86400 $qclass NS ns1.1.example.org"); + push @auth, $rr; + } elsif ($qtype eq "A") { + my ($ttl, $rdata) = (3600, $localaddr); + my $rr = new Net::DNS::RR("$qname $ttl $qclass $qtype $rdata"); + push @ans, $rr; + } + $rcode = "NOERROR"; + } elsif ($qname =~ /^ns1\.(\d+)\.example\.org$/) { + my $next = $1 + 1; + $wait = 1; + if ($limit == 0 || (! $send_response && $next <= $limit)) { + my $rr = new Net::DNS::RR("$1.example.org 86400 $qclass NS ns1.$next.example.org"); + push @auth, $rr; + } else { + $send_response = 1; + if ($qtype eq "A") { + my ($ttl, $rdata) = (3600, "10.53.0.4"); + my $rr = new Net::DNS::RR("$qname $ttl $qclass $qtype $rdata"); + print("\tresponse: $qname $ttl $qclass $qtype $rdata\n"); + push @ans, $rr; + } + } + $rcode = "NOERROR"; + } elsif ($qname eq "direct.example.net" ) { + if ($qtype eq "A") { + my ($ttl, $rdata) = (3600, $localaddr); + my $rr = new Net::DNS::RR("$qname $ttl $qclass $qtype $rdata"); + push @ans, $rr; + } + $rcode = "NOERROR"; + } elsif( $qname =~ /^ns1\.(\d+)\.example\.net$/ ) { + my $next = ($1 + 1) * 16; + for (my $i = 1; $i < 16; $i++) { + my $s = $next + $i; + my $rr = new Net::DNS::RR("$1.example.net 86400 $qclass NS ns1.$s.example.net"); + push @auth, $rr; + $rr = new Net::DNS::RR("ns1.$s.example.net 86400 $qclass A 10.53.0.7"); + push @add, $rr; + } + $rcode = "NOERROR"; + } else { + $rcode = "NXDOMAIN"; + } + + return ($rcode, \@ans, \@auth, \@add, $wait); +} + +sub handleUDP { + my ($buf, $peer) = @_; + my ($request, $rcode, $ans, $auth, $add, $wait); + + $request = new Net::DNS::Packet(\$buf, 0); + $@ and die $@; + + my ($question) = $request->question; + my $qname = $question->qname; + my $qclass = $question->qclass; + my $qtype = $question->qtype; + + ($rcode, $ans, $auth, $add, $wait) = reply_handler($qname, $qclass, $qtype); + + my $reply = $request->reply(); + + $reply->header->rcode($rcode); + $reply->header->aa(@$ans ? 1 : 0); + $reply->header->id($request->header->id); + $reply->{answer} = $ans if $ans; + $reply->{authority} = $auth if $auth; + $reply->{additional} = $add if $add; + + if ($wait) { + # reply_handler() asked us to delay sending this reply until + # another reply with $wait == 1 is generated or a timeout + # occurs. + if (@delayed_response) { + # A delayed reply is already queued, so we can now send + # both the delayed reply and the current reply. + send_delayed_response(); + return $reply; + } elsif ($no_more_waiting) { + # It was determined before that there is no point in + # waiting for "accompanying" queries. Thus, send the + # current reply immediately. + return $reply; + } else { + # No delayed reply is queued and the client is expected + # to send an "accompanying" query shortly. Do not send + # the current reply right now, just save it for later + # and wait for an "accompanying" query to be received. + @delayed_response = ($reply, $peer); + $timeout = 0.5; + return; + } + } else { + # Send reply immediately. + return $reply; + } +} + +sub send_delayed_response { + my ($reply, $peer) = @delayed_response; + # Truncation to 512 bytes is required for triggering "NS explosion" on + # builds without IPv6 support + $udpsock->send($reply->data(512), 0, $peer); + undef @delayed_response; + undef $timeout; +} + +# Main +my $rin; +my $rout; +for (;;) { + $rin = ''; + vec($rin, fileno($udpsock), 1) = 1; + + select($rout = $rin, undef, undef, $timeout); + + if (vec($rout, fileno($udpsock), 1)) { + my ($buf, $peer, $reply); + $udpsock->recv($buf, 512); + $peer = $udpsock->peername(); + $reply = handleUDP($buf, $peer); + # Truncation to 512 bytes is required for triggering "NS + # explosion" on builds without IPv6 support + $udpsock->send($reply->data(512), 0, $peer) if $reply; + } else { + # An "accompanying" query was expected to come in, but did not. + # Assume the client never sends "accompanying" queries to + # prevent pointlessly waiting for them ever again. + $no_more_waiting = 1; + # Send the delayed reply to the query which caused us to wait. + send_delayed_response(); + } +} |