From: Štěpán Balážik Date: Thu, 25 Dec 2025 16:03:20 +0000 (+0100) Subject: Reimplement 'resolver/ans3' server using AsyncDnsServer X-Git-Tag: v9.21.18~11^2~3 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5004d278e49d84bd80479c0c5a842b3fb4d58c19;p=thirdparty%2Fbind9.git Reimplement 'resolver/ans3' server using AsyncDnsServer Ensure packet-for-packet compatibility with the old server including bugs. --- diff --git a/bin/tests/system/resolver/ans3/ans.pl b/bin/tests/system/resolver/ans3/ans.pl deleted file mode 100644 index 02a8c1d6a60..00000000000 --- a/bin/tests/system/resolver/ans3/ans.pl +++ /dev/null @@ -1,234 +0,0 @@ -#!/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. - -# -# Ad hoc name server -# - -use IO::File; -use IO::Socket; -use Net::DNS; -use Net::DNS::Packet; - -# 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 $localport = int($ENV{'PORT'}); -if (!$localport) { $localport = 5300; } - -my $server_addr = "10.53.0.3"; - -my $udpsock = IO::Socket::INET->new(LocalAddr => "$server_addr", - LocalPort => $localport, Proto => "udp", Reuse => 1) or die "$!"; -my $tcpsock = IO::Socket::INET->new(LocalAddr => "$server_addr", - LocalPort => $localport, Proto => "tcp", Listen => 5, Reuse => 1) or die "$!"; - -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; - -sub handleQuery { - my $buf = shift; - my $packet; - - if ($Net::DNS::VERSION > 0.68) { - $packet = new Net::DNS::Packet(\$buf, 0); - $@ and die $@; - } else { - my $err; - ($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; - my $qtype = $questions[0]->qtype; - - if ($qname eq "example.net" && $qtype eq "NS") { - $packet->push("answer", new Net::DNS::RR($qname . " 300 NS ns.example.net")); - $packet->push("additional", new Net::DNS::RR("ns.example.net 300 A 10.53.0.3")); - } elsif ($qname eq "ns.example.net") { - $packet->push("answer", new Net::DNS::RR($qname . " 300 A 10.53.0.3")); - } elsif ($qname eq "nodata.example.net") { - # Do not add a SOA RRset. - } elsif ($qname eq "noresponse.example.net") { - # Do not response. - print "RESPONSE:\n"; - return ""; - } elsif ($qname eq "nxdomain.example.net") { - # Do not add a SOA RRset. - $packet->header->rcode(NXDOMAIN); - } elsif ($qname eq "www.example.net") { - # Data for address/alias filtering. - if ($qtype eq "A") { - $packet->push("answer", new Net::DNS::RR($qname . " 300 A 192.0.2.1")); - } elsif ($qtype eq "AAAA") { - $packet->push("answer", new Net::DNS::RR($qname . " 300 AAAA 2001:db8:beef::1")); - } - } elsif ($qname eq "badcname.example.net") { - $packet->push("answer", - new Net::DNS::RR($qname . - " 300 CNAME badcname.example.org")); - } elsif (($qname eq "baddname.example.net" || $qname eq "gooddname.example.net") && $qtype eq "NS") { - $packet->push("authority", new Net::DNS::RR("example.net IN SOA (1 2 3 4 5)")) - } elsif ($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 =~ /^longcname/) { - $cname = $qname =~ s/longcname/longcnamex/r; - $packet->push("answer", new Net::DNS::RR($qname . " 300 CNAME " . $cname)); - } elsif ($qname =~ /^nodata\.example\.net$/i) { - $packet->header->aa(1); - } elsif ($qname =~ /^nxdomain\.example\.net$/i) { - $packet->header->aa(1); - $packet->header->rcode(NXDOMAIN); - } elsif ($qname =~ /lame\.example\.org/) { - $packet->header->ad(0); - $packet->header->aa(0); - $packet->push("authority", new Net::DNS::RR("lame.example.org 300 NS ns.lame.example.org")); - $packet->push("additional", new Net::DNS::RR("ns.lame.example.org 300 A 10.53.0.3")); - } elsif ($qname eq "large-referral.example.net") { - for (my $i = 1; $i < 1000; $i++) { - $packet->push("authority", new Net::DNS::RR("large-referral.example.net 300 NS ns" . $i . ".fake.redirect.com")); - } - # No glue records - } elsif ($qname eq "foo.bar.sub.tld1") { - $packet->push("answer", new Net::DNS::RR("$qname 300 TXT baz")); - } 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")); - } elsif ($qname eq "foo.glue-in-answer.example.org") { - $packet->push("answer", new Net::DNS::RR($qname . " 300 A 192.0.2.1")); - } elsif ($qname eq "ns.example.net") { - $packet->push("answer", - new Net::DNS::RR($qname . - " 300 A 10.53.0.3")); - } elsif ($qname =~ /\.partial-formerr/) { - $packet->push("answer", - new Net::DNS::RR($qname . " 1 A 10.53.0.3")); - } elsif ($qname eq "gl6412") { - if ($qtype eq "SOA") { - $packet->push("answer", - new Net::DNS::RR($qname . " 300 SOA . . 0 0 0 0 0")); - } elsif ($qtype eq "NS") { - $packet->push("answer", - new Net::DNS::RR($qname . " 300 NS ns2" . $qname)); - $packet->push("answer", - new Net::DNS::RR($qname . " 300 NS ns3" . $qname)); - } else { - $packet->push("authority", - new Net::DNS::RR($qname . " 300 SOA . . 0 0 0 0 0")); - } - } elsif ($qname eq "a.gl6412" || $qname eq "a.a.gl6412") { - $packet->push("authority", - new Net::DNS::RR($qname . " 300 SOA . . 0 0 0 0 0")); - } elsif ($qname eq "ns2.gl6412") { - if ($qtype eq "A") { - $packet->push("answer", - new Net::DNS::RR($qname . " 300 A 10.53.0.2")); - } else { - $packet->push("authority", - new Net::DNS::RR($qname . " 300 SOA . . 0 0 0 0 0")); - } - } elsif ($qname eq "ns3.gl6412") { - if ($qtype eq "A") { - $packet->push("answer", - new Net::DNS::RR($qname . " 300 A 10.53.0.3")); - } else { - $packet->push("authority", - new Net::DNS::RR($qname . " 300 SOA . . 0 0 0 0 0")); - } - } else { - $packet->push("answer", new Net::DNS::RR("www.example.com 300 A 1.2.3.4")); - } - - print "RESPONSE:\n"; - $packet->print; - - return $packet->data; -} - -# Main -my $rin; -my $rout; -for (;;) { - $rin = ''; - vec($rin, fileno($tcpsock), 1) = 1; - vec($rin, fileno($udpsock), 1) = 1; - - select($rout = $rin, undef, undef, undef); - - if (vec($rout, fileno($udpsock), 1)) { - printf "UDP request\n"; - my $buf; - $udpsock->recv($buf, 512); - my $result = handleQuery($buf); - my $num_chars = $udpsock->send($result); - print " Sent $num_chars bytes via UDP\n"; - } elsif (vec($rout, fileno($tcpsock), 1)) { - my $conn = $tcpsock->accept; - my $buf; - for (;;) { - my $lenbuf; - my $n = $conn->sysread($lenbuf, 2); - last unless $n == 2; - my $len = unpack("n", $lenbuf); - $n = $conn->sysread($buf, $len); - last unless $n == $len; - print "TCP request\n"; - my $result = handleQuery($buf); - $len = length($result); - if ($len != 0) { - $conn->syswrite(pack("n", $len), 2); - $n = $conn->syswrite($result, $len); - } else { - $n = 0; - } - print " Sent: $n chars via TCP\n"; - } - $conn->close; - } -} diff --git a/bin/tests/system/resolver/ans3/ans.py b/bin/tests/system/resolver/ans3/ans.py new file mode 100644 index 00000000000..2594c98a243 --- /dev/null +++ b/bin/tests/system/resolver/ans3/ans.py @@ -0,0 +1,233 @@ +""" +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. +""" + +from typing import AsyncGenerator + +import dns.name +import dns.rcode +import dns.rdatatype + +from isctest.asyncserver import ( + AsyncDnsServer, + DnsResponseSend, + DomainHandler, + IgnoreAllQueries, + QnameHandler, + QnameQtypeHandler, + QueryContext, + StaticResponseHandler, + ResponseHandler, +) + +from resolver_ans import ( + DelegationHandler, + Gl6412AHandler, + Gl6412Handler, + Gl6412Ns2Handler, + Gl6412Ns3Handler, + rrset, + rrset_from_list, + soa_rrset, +) + + +class ApexNSHandler(QnameHandler, StaticResponseHandler): + qnames = ["example.net."] + qtypes = [dns.rdatatype.NS] + answer = [rrset(qnames[0], dns.rdatatype.NS, f"ns.{qnames[0]}")] + additional = [rrset(f"ns.{qnames[0]}", dns.rdatatype.A, "10.53.0.3")] + + +class BadCnameHandler(QnameHandler, StaticResponseHandler): + qnames = ["badcname.example.net."] + answer = [rrset(qnames[0], dns.rdatatype.CNAME, "badcname.example.org.")] + + +class BadGoodDnameNsHandler(QnameQtypeHandler, StaticResponseHandler): + qnames = ["baddname.example.net.", "gooddname.example.net."] + qtypes = [dns.rdatatype.NS] + # XXX: This should really be, for brevity: + # authority = [soa_rrset("example.net.")] + # But we are reproducing the exact behavior of the original server. + authority = [ + rrset("example.net.", dns.rdatatype.SOA, "1. 2. 3 4 5 1814400 3600", ttl=0) + ] + + +class CnameSubHandler(QnameHandler, StaticResponseHandler): + qnames = ["cname.sub.example.org."] + answer = [rrset(qnames[0], dns.rdatatype.CNAME, "ok.sub.example.org.")] + + +class FooBadDnameHandler(QnameHandler, StaticResponseHandler): + qnames = ["foo.baddname.example.net."] + answer = [ + rrset("baddname.example.net.", dns.rdatatype.DNAME, "baddname.example.org.") + ] + + +class FooBarSubTld1Handler(QnameHandler, StaticResponseHandler): + qnames = ["foo.bar.sub.tld1."] + answer = [rrset(qnames[0], dns.rdatatype.TXT, "baz")] + + +class FooGlueInAnswerHandler(QnameHandler, StaticResponseHandler): + qnames = ["foo.glue-in-answer.example.org."] + answer = [rrset(qnames[0], dns.rdatatype.A, "192.0.2.1")] + + +class FooGoodDnameHandler(QnameHandler, StaticResponseHandler): + qnames = ["foo.gooddname.example.net."] + answer = [ + rrset("gooddname.example.net.", dns.rdatatype.DNAME, "gooddname.example.org.") + ] + + +class GoodCnameHandler(QnameHandler, StaticResponseHandler): + qnames = ["goodcname.example.net."] + answer = [rrset(qnames[0], dns.rdatatype.CNAME, "goodcname.example.org.")] + + +class LameExampleOrgDelegation(DelegationHandler): + domains = ["lame.example.org."] + server_number = 3 + + +class LargeReferralHandler(QnameHandler, StaticResponseHandler): + qnames = ["large-referral.example.net."] + qtypes = [dns.rdatatype.NS] + authority = [ + rrset_from_list( + qnames[0], + dns.rdatatype.NS, + [f"ns{i}.fake.redirect.com." for i in range(1, 1000)], + ) + ] + + +class LongCnameHandler(ResponseHandler): + def match(self, qctx: QueryContext) -> bool: + return qctx.qname.labels[0].startswith(b"longcname") + + async def get_responses( + self, qctx: QueryContext + ) -> AsyncGenerator[DnsResponseSend, None]: + first_label = qctx.qname.labels[0].replace(b"longcname", b"longcnamex") + cname_target = f"{dns.name.Name((first_label,) + qctx.qname.labels[1:])}" + qctx.response.answer.append( + rrset(qctx.qname, dns.rdatatype.CNAME, cname_target) + ) + yield DnsResponseSend(qctx.response) + + +class NodataHandler(QnameHandler, StaticResponseHandler): + qnames = ["nodata.example.net."] + + +class NoresponseHandler(QnameHandler, IgnoreAllQueries): + qnames = ["noresponse.example.net."] + + +class NsHandler(QnameHandler, StaticResponseHandler): + qnames = ["ns.example.net."] + answer = [rrset(qnames[0], dns.rdatatype.A, "10.53.0.3")] + + +class NxdomainHandler(QnameHandler, StaticResponseHandler): + qnames = ["nxdomain.example.net."] + rcode = dns.rcode.NXDOMAIN + + +class OkSubHandler(QnameHandler): + qnames = ["ok.sub.example.org.", "www.ok.sub.example.org."] + + async def get_responses( + self, qctx: QueryContext + ) -> AsyncGenerator[DnsResponseSend, None]: + qctx.response.answer.append(rrset(qctx.qname, dns.rdatatype.A, "192.0.2.1")) + yield DnsResponseSend(qctx.response) + + +class PartialFormerrHandler(DomainHandler): + domains = ["partial-formerr."] + + async def get_responses( + self, qctx: QueryContext + ) -> AsyncGenerator[DnsResponseSend, None]: + qctx.response.answer.append( + rrset(qctx.qname, dns.rdatatype.A, "10.53.0.3", ttl=1) + ) + yield DnsResponseSend(qctx.response) + + +class WwwDnameSubHandler(QnameHandler, StaticResponseHandler): + qnames = ["www.dname.sub.example.org."] + answer = [ + rrset("dname.sub.example.org.", dns.rdatatype.DNAME, "ok.sub.example.org.") + ] + + +class WwwHandler(QnameHandler): + qnames = ["www.example.net."] + + async def get_responses( + self, qctx: QueryContext + ) -> AsyncGenerator[DnsResponseSend, None]: + if qctx.qtype == dns.rdatatype.A: + qctx.response.answer.append(rrset(qctx.qname, dns.rdatatype.A, "192.0.2.1")) + elif qctx.qtype == dns.rdatatype.AAAA: + qctx.response.answer.append( + rrset(qctx.qname, dns.rdatatype.AAAA, "2001:db8:beef::1") + ) + yield DnsResponseSend(qctx.response) + + +class FallbackHandler(StaticResponseHandler): + answer = [rrset("www.example.com.", dns.rdatatype.A, "1.2.3.4")] + + +def main() -> None: + server = AsyncDnsServer(default_aa=True, default_rcode=dns.rcode.NOERROR) + server.install_response_handlers( + ApexNSHandler(), + BadCnameHandler(), + BadGoodDnameNsHandler(), + CnameSubHandler(), + FooBadDnameHandler(), + FooBarSubTld1Handler(), + FooGoodDnameHandler(), + FooGlueInAnswerHandler(), + Gl6412AHandler(), + Gl6412Handler(), + Gl6412Ns2Handler(), + Gl6412Ns3Handler(), + GoodCnameHandler(), + LameExampleOrgDelegation(), + LargeReferralHandler(), + LongCnameHandler(), + NodataHandler(), + NoresponseHandler(), + NsHandler(), + NxdomainHandler(), + OkSubHandler(), + PartialFormerrHandler(), + WwwDnameSubHandler(), + WwwHandler(), + ) + + server.install_response_handler(FallbackHandler()) + server.run() + + +if __name__ == "__main__": + main()