upstream/bind9
1
0
Fork 0
mirror of https://github.com/isc-projects/bind9.git synced 2026-05-26 19:34:04 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 2

Reimplement 'resolver/ans3' server using AsyncDnsServer

Browse source 
Ensure packet-for-packet compatibility with the old server including
bugs.

(cherry picked from commit 5004d278e4)
This commit is contained in:
Štěpán Balážik 2025-12-25 17:03:20 +01:00
parent aa658f80d7
commit fdcdcbc0e2
2 changed files with 233 additions and 234 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

234
bin/tests/system/resolver/ans3/ans.pl
View file

@ -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;
}
}

233
bin/tests/system/resolver/ans3/ans.py Normal file
View file

@ -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()