[9.20] chg: test: Use isctest.asyncserver in the "ixfr" test

Backport of MR !11403

Merge branch 'backport-stepan/ixfr-asyncserver-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!11453

bin/tests/system/chain/ans3/ans.py

@@ -114,7 +114,7 @@ class Cve202125215(DomainHandler):
 
 def main() -> None:
     server = AsyncDnsServer(acknowledge_manual_dname_handling=True, default_aa=True)
-    server.install_response_handlers([CnameThenDnameHandler(), Cve202125215()])
+    server.install_response_handlers(CnameThenDnameHandler(), Cve202125215())
     server.run()
 
 

bin/tests/system/cookie/cookie_ans.py

@@ -194,13 +194,11 @@ def cookie_server(evil: bool) -> AsyncDnsServer:
         keyring=KEYRING, default_aa=True, default_rcode=dns.rcode.NOERROR
     )
     server.install_response_handlers(
-        [
-            NsHandler(evil),
-            GlueHandler(evil),
-            TcpAHandler(),
-            WithtsigUdpAHandler(),
-            UdpAHandler(),
-            FallbackHandler(),
-        ]
+        NsHandler(evil),
+        GlueHandler(evil),
+        TcpAHandler(),
+        WithtsigUdpAHandler(),
+        UdpAHandler(),
     )
+    server.install_response_handler(FallbackHandler())
     return server

bin/tests/system/digdelv/ans7/ans.py

@@ -63,11 +63,9 @@ class SilentThenServfailHandler(DomainHandler):
 def main() -> None:
     server = AsyncDnsServer()
     server.install_response_handlers(
-        [
-            CloseHandler(),
-            SilentHandler(),
-            SilentThenServfailHandler(),
-        ]
+        CloseHandler(),
+        SilentHandler(),
+        SilentThenServfailHandler(),
     )
     server.run()
 

bin/tests/system/dnssec/ans10/ans.py

@@ -57,7 +57,7 @@ class AddNsecToTxtHandler(ResponseHandler):
 
 def main() -> None:
     server = AsyncDnsServer()
-    server.install_response_handlers([AddRrsigToAHandler(), AddNsecToTxtHandler()])
+    server.install_response_handlers(AddNsecToTxtHandler(), AddRrsigToAHandler())
     server.run()
 
 

bin/tests/system/isctest/asyncserver.py

@@ -21,6 +21,7 @@ from typing import (
     List,
     Optional,
     Set,
+    Sequence,
     Tuple,
     Union,
     cast,
@@ -887,10 +888,18 @@ class AsyncDnsServer(AsyncServer):
         else:
             self._response_handlers.append(handler)
 
-    def install_response_handlers(self, handlers: List[ResponseHandler]) -> None:
+    def install_response_handlers(self, *handlers: ResponseHandler) -> None:
         for handler in handlers:
             self.install_response_handler(handler)
 
+    def replace_response_handlers(self, *new_handlers: ResponseHandler) -> None:
+        """
+        Uninstall all currently installed handlers and install the provided ones.
+        """
+        logging.info("Uninstalling response handlers: %s", str(self._response_handlers))
+        self._response_handlers.clear()
+        self.install_response_handlers(*new_handlers)
+
     def uninstall_response_handler(self, handler: ResponseHandler) -> None:
         """
         Remove the specified handler from the list of response handlers.
@@ -1380,7 +1389,7 @@ class ControllableAsyncDnsServer(AsyncDnsServer):
     def _commands(self) -> Dict[dns.name.Name, "ControlCommand"]:
         return {}
 
-    def install_control_commands(self, commands: List["ControlCommand"]) -> None:
+    def install_control_commands(self, *commands: "ControlCommand") -> None:
         for command in commands:
             self.install_control_command(command)
 
@@ -1556,3 +1565,30 @@ class ToggleResponsesCommand(ControlCommand):
         logging.error("Unrecognized response sending mode '%s'", mode)
         qctx.response.set_rcode(dns.rcode.SERVFAIL)
         return f"unrecognized response sending mode '{mode}'"
+
+
+class SwitchControlCommand(ControlCommand):
+    """
+    Switch the server's response handlers based on the control query.
+
+    A sequence of response handlers is associated with each key.  When a
+    control query is received, the server's response handlers are replaced
+    with the sequence associated with the key extracted from the control
+    query.
+    """
+
+    control_subdomain = "switch"
+
+    def __init__(self, handler_mapping: Dict[str, Sequence[ResponseHandler]]):
+        self._handler_mapping = handler_mapping
+
+    def handle(
+        self, args: List[str], server: ControllableAsyncDnsServer, qctx: QueryContext
+    ) -> Optional[str]:
+        if len(args) != 1 or args[0] not in self._handler_mapping:
+            logging.error("Invalid %s query %s", self, qctx.qname)
+            qctx.response.set_rcode(dns.rcode.SERVFAIL)
+            return f"invalid query; exactly one of {list(self._handler_mapping.keys())} is expected in QNAME"
+
+        server.replace_response_handlers(*self._handler_mapping[args[0]])
+        return f"switched to handler set '{args[0]}'"

bin/tests/system/ixfr/ans2/ans.py

@@ -0,0 +1,265 @@
+"""
+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.
+"""
+
+import abc
+
+import dns.rcode
+import dns.rdataclass
+import dns.rdatatype
+import dns.rrset
+
+from typing import AsyncGenerator, Collection, Iterable
+
+from isctest.asyncserver import (
+    ControllableAsyncDnsServer,
+    DnsResponseSend,
+    QueryContext,
+    ResponseHandler,
+    SwitchControlCommand,
+)
+
+
+def rrset(owner: str, rdtype: dns.rdatatype.RdataType, rdata: str) -> dns.rrset.RRset:
+    return dns.rrset.from_text(
+        owner,
+        300,
+        dns.rdataclass.IN,
+        rdtype,
+        rdata,
+    )
+
+
+def soa(serial: int, *, owner: str = "nil.") -> dns.rrset.RRset:
+    return rrset(
+        owner,
+        dns.rdatatype.SOA,
+        f"ns.nil. root.nil. {serial} 300 300 604800 300",
+    )
+
+
+def ns() -> dns.rrset.RRset:
+    return rrset(
+        "nil.",
+        dns.rdatatype.NS,
+        "ns.nil.",
+    )
+
+
+def a(address: str, *, owner: str) -> dns.rrset.RRset:
+    return rrset(
+        owner,
+        dns.rdatatype.A,
+        address,
+    )
+
+
+def txt(data: str, *, owner: str = "nil.") -> dns.rrset.RRset:
+    return rrset(
+        owner,
+        dns.rdatatype.TXT,
+        f'"{data}"',
+    )
+
+
+class SoaHandler(ResponseHandler):
+    def __init__(self, serial: int):
+        self._serial = serial
+
+    def match(self, qctx: QueryContext) -> bool:
+        return qctx.qtype == dns.rdatatype.SOA
+
+    async def get_responses(
+        self, qctx: QueryContext
+    ) -> AsyncGenerator[DnsResponseSend, None]:
+        qctx.response.answer.append(soa(self._serial))
+        yield DnsResponseSend(qctx.response)
+
+
+class AxfrHandler(ResponseHandler):
+    @property
+    @abc.abstractmethod
+    def answers(self) -> Iterable[Collection[dns.rrset.RRset]]:
+        """
+        Answer sections of response packets sent in response to
+        AXFR queries.
+        """
+        raise NotImplementedError
+
+    def match(self, qctx: QueryContext) -> bool:
+        return qctx.qtype == dns.rdatatype.AXFR
+
+    async def get_responses(
+        self, qctx: QueryContext
+    ) -> AsyncGenerator[DnsResponseSend, None]:
+        for answer in self.answers:
+            response = qctx.prepare_new_response()
+            for rrset_ in answer:
+                response.answer.append(rrset_)
+            yield DnsResponseSend(response)
+
+
+class IxfrHandler(ResponseHandler):
+    @property
+    @abc.abstractmethod
+    def answer(self) -> Collection[dns.rrset.RRset]:
+        """
+        Answer section of a response packet sent in response to
+        IXFR queries.
+        """
+        raise NotImplementedError
+
+    def match(self, qctx: QueryContext) -> bool:
+        return qctx.qtype == dns.rdatatype.IXFR
+
+    async def get_responses(
+        self, qctx: QueryContext
+    ) -> AsyncGenerator[DnsResponseSend, None]:
+        for rrset_ in self.answer:
+            qctx.response.answer.append(rrset_)
+        yield DnsResponseSend(qctx.response)
+
+
+class InitialAfxrHandler(AxfrHandler):
+    answers = (
+        (soa(1),),
+        (
+            ns(),
+            txt("initial AXFR"),
+            a("10.0.0.61", owner="a.nil."),
+            a("10.0.0.62", owner="b.nil."),
+        ),
+        (soa(1),),
+    )
+
+
+class SuccessfulIfxrHandler(IxfrHandler):
+    answer = (
+        soa(3),
+        soa(1),
+        a("10.0.0.61", owner="a.nil."),
+        txt("initial AXFR"),
+        soa(2),
+        txt("successful IXFR"),
+        a("10.0.1.61", owner="a.nil."),
+        soa(2),
+        soa(3),
+        soa(3),
+    )
+
+
+class NotExactIxfrHandler(IxfrHandler):
+    answer = (
+        soa(4),
+        soa(3),
+        txt("delete-nonexistent-txt-record"),
+        soa(4),
+        txt("this-txt-record-would-be-added"),
+        soa(4),
+    )
+
+
+class FallbackNotExactAxfrHandler(AxfrHandler):
+    answers = (
+        (soa(3),),
+        (
+            ns(),
+            txt("fallback AXFR"),
+        ),
+        (soa(3),),
+    )
+
+
+class TooManyRecordsIxfrHandler(IxfrHandler):
+    answer = (
+        soa(4),
+        soa(3),
+        soa(4),
+        txt("text 1"),
+        txt("text 2"),
+        txt("text 3"),
+        txt("text 4"),
+        txt("text 5"),
+        txt("text 6: causing too many records"),
+        soa(4),
+    )
+
+
+class FallbackTooManyRecordsAxfrHandler(AxfrHandler):
+    answers = (
+        (
+            soa(3),
+            ns(),
+            txt("fallback AXFR on too many records"),
+        ),
+        (soa(3),),
+    )
+
+
+class BadSoaOwnerIxfrHandler(IxfrHandler):
+    answer = (
+        soa(4),
+        soa(3),
+        soa(4, owner="bad-owner."),
+        txt("serial 4, malformed IXFR", owner="test.nil."),
+        soa(4),
+    )
+
+
+class FallbackBadSoaOwnerAxfrHandler(AxfrHandler):
+    answers = (
+        (soa(4),),
+        (
+            ns(),
+            txt("serial 4, fallback AXFR", owner="test.nil."),
+        ),
+        (soa(4),),
+    )
+
+
+def main() -> None:
+    server = ControllableAsyncDnsServer(
+        default_aa=True, default_rcode=dns.rcode.NOERROR
+    )
+    switch_command = SwitchControlCommand(
+        {
+            "initial_axfr": (
+                SoaHandler(1),
+                InitialAfxrHandler(),
+            ),
+            "successful_ixfr": (
+                SoaHandler(3),
+                SuccessfulIfxrHandler(),
+            ),
+            "not_exact": (
+                SoaHandler(4),
+                NotExactIxfrHandler(),
+                FallbackNotExactAxfrHandler(),
+            ),
+            "too_many_records": (
+                SoaHandler(4),
+                TooManyRecordsIxfrHandler(),
+                FallbackTooManyRecordsAxfrHandler(),
+            ),
+            "bad_soa_owner": (
+                SoaHandler(4),
+                BadSoaOwnerIxfrHandler(),
+                FallbackBadSoaOwnerAxfrHandler(),
+            ),
+        }
+    )
+    server.install_control_command(switch_command)
+    server.run()
+
+
+if __name__ == "__main__":
+    main()

bin/tests/system/ixfr/tests.sh

@@ -32,27 +32,16 @@ n=0
 DIGOPTS="+tcp +noadd +nosea +nostat +noquest +nocomm +nocmd -p ${PORT}"
 RNDCCMD="$RNDC -p ${CONTROLPORT} -c ../_common/rndc.conf -s"
 
-sendcmd() {
-  send 10.53.0.2 "${EXTRAPORT1}"
+switch_responses() {
+  RESPONSES_KEY="${1}"
+  $DIG $DIGOPTS "@10.53.0.2" "${RESPONSES_KEY}.switch._control." TXT +time=5 +tries=1 +tcp >/dev/null 2>&1
 }
 
 n=$((n + 1))
 echo_i "testing initial AXFR ($n)"
 ret=0
 
-sendcmd <<EOF
-/SOA/
-nil.      	300	SOA	ns.nil. root.nil. 1 300 300 604800 300
-/AXFR/
-nil.      	300	SOA	ns.nil. root.nil. 1 300 300 604800 300
-/AXFR/
-nil.      	300	NS	ns.nil.
-nil.		300	TXT	"initial AXFR"
-a.nil.		60	A	10.0.0.61
-b.nil.		60	A	10.0.0.62
-/AXFR/
-nil.      	300	SOA	ns.nil. root.nil. 1 300 300 604800 300
-EOF
+switch_responses "initial_axfr"
 
 sleep 1
 
@@ -84,21 +73,7 @@ ret=0
 # We change the IP address of a.nil., and the TXT record at the apex.
 # Then we do a SOA-only update.
 
-sendcmd <<EOF
-/SOA/
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-/IXFR/
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-nil.      	300	SOA	ns.nil. root.nil. 1 300 300 604800 300
-a.nil.      	60	A	10.0.0.61
-nil.		300	TXT	"initial AXFR"
-nil.      	300	SOA	ns.nil. root.nil. 2 300 300 604800 300
-nil.		300	TXT	"successful IXFR"
-a.nil.      	60	A	10.0.1.61
-nil.      	300	SOA	ns.nil. root.nil. 2 300 300 604800 300
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-EOF
+switch_responses "successful_ixfr"
 
 sleep 1
 
@@ -115,25 +90,7 @@ echo_i "testing AXFR fallback after IXFR failure (not exact error) ($n)"
 ret=0
 
 # Provide a broken IXFR response and a working fallback AXFR response
-
-sendcmd <<EOF
-/SOA/
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-/IXFR/
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-nil.      	300	TXT	"delete-nonexistent-txt-record"
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-nil.      	300	TXT	"this-txt-record-would-be-added"
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-/AXFR/
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-/AXFR/
-nil.      	300	NS	ns.nil.
-nil.      	300	TXT	"fallback AXFR"
-/AXFR/
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-EOF
+switch_responses "not_exact"
 
 sleep 1
 
@@ -150,28 +107,7 @@ echo_i "testing AXFR fallback after IXFR failure (too many records) ($n)"
 ret=0
 
 # Provide an IXFR response that would cause a "too many records" condition
-
-sendcmd <<EOF
-/SOA/
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-/IXFR/
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-nil.      	300	TXT	"text 1"
-nil.      	300	TXT	"text 2"
-nil.      	300	TXT	"text 3"
-nil.      	300	TXT	"text 4"
-nil.      	300	TXT	"text 5"
-nil.      	300	TXT	"text 6: causing too many records"
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-/AXFR/
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-nil.      	300	NS	ns.nil.
-nil.      	300	TXT	"fallback AXFR on too many records"
-/AXFR/
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-EOF
+switch_responses "too_many_records"
 
 sleep 1
 
@@ -196,23 +132,7 @@ ret=0
 nextpart ns1/named.run >/dev/null
 
 # Provide a broken IXFR response and a working fallback AXFR response.
-sendcmd <<EOF
-/SOA/
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-/IXFR/
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-nil.      	300	SOA	ns.nil. root.nil. 3 300 300 604800 300
-bad-owner.    	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-test.nil.	300	TXT	"serial 4, malformed IXFR"
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-/AXFR/
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-/AXFR/
-nil.      	300	NS	ns.nil.
-test.nil.      	300	TXT	"serial 4, fallback AXFR"
-/AXFR/
-nil.      	300	SOA	ns.nil. root.nil. 4 300 300 604800 300
-EOF
+switch_responses "bad_soa_owner"
 $RNDCCMD 10.53.0.1 refresh nil | sed 's/^/ns1 /' | cat_i
 
 # A broken server would accept the malformed IXFR and apply its contents to the

bin/tests/system/ixfr/tests_sh_ixfr.py

@@ -11,6 +11,9 @@
 
 import pytest
 
+# isctest.asyncserver requires dnspython >= 2.0.0
+pytest.importorskip("dns", minversion="2.0.0")
+
 pytestmark = pytest.mark.extra_artifacts(
     [
         "dig.out*",

bin/tests/system/qmin/ans2/ans.py

@@ -100,13 +100,11 @@ class StaleHandler(DomainHandler):
 def main() -> None:
     server = AsyncDnsServer()
     server.install_response_handlers(
-        [
-            QueryLogger(),
-            BadHandler(),
-            UglyHandler(),
-            SlowHandler(),
-            StaleHandler(),
-        ]
+        QueryLogger(),
+        BadHandler(),
+        UglyHandler(),
+        SlowHandler(),
+        StaleHandler(),
     )
     server.run()
 

bin/tests/system/qmin/ans3/ans.py

@@ -40,12 +40,10 @@ class ZoopBoingSlowHandler(DelayedResponseHandler):
 def main() -> None:
     server = AsyncDnsServer()
     server.install_response_handlers(
-        [
-            QueryLogger(),
-            ZoopBoingBadHandler(),
-            ZoopBoingUglyHandler(),
-            ZoopBoingSlowHandler(),
-        ]
+        QueryLogger(),
+        ZoopBoingBadHandler(),
+        ZoopBoingUglyHandler(),
+        ZoopBoingSlowHandler(),
     )
     server.run()
 

bin/tests/system/qmin/ans4/ans.py

@@ -87,13 +87,11 @@ class IckyPtangZoopBoingSlowHandler(DelayedResponseHandler):
 def main() -> None:
     server = AsyncDnsServer()
     server.install_response_handlers(
-        [
-            QueryLogger(),
-            StaleHandler(),
-            IckyPtangZoopBoingBadHandler(),
-            IckyPtangZoopBoingUglyHandler(),
-            IckyPtangZoopBoingSlowHandler(),
-        ]
+        QueryLogger(),
+        StaleHandler(),
+        IckyPtangZoopBoingBadHandler(),
+        IckyPtangZoopBoingUglyHandler(),
+        IckyPtangZoopBoingSlowHandler(),
     )
     server.run()
 

bin/tests/system/rpzrecurse/ans5/ans.py

@@ -52,7 +52,7 @@ class IgnoreNs(ResponseHandler):
 
 def main() -> None:
     server = AsyncDnsServer(default_aa=True, default_rcode=dns.rcode.NOERROR)
-    server.install_response_handlers([ReplyA(), IgnoreNs()])
+    server.install_response_handlers(ReplyA(), IgnoreNs())
     server.run()
 
 

bin/tests/system/statistics/ans4/ans.py

@@ -162,18 +162,16 @@ class FallbackHandler(ResponseHandler):
 def main() -> None:
     server = AsyncDnsServer(default_rcode=dns.rcode.NOERROR)
     server.install_response_handlers(
-        [
-            BadGoodCnameHandler(),
-            Cname1Handler(),
-            Cname2Handler(),
-            ExampleHandler(),
-            FooInfoHandler(),
-            NoDataHandler(),
-            NxdomainHandler(),
-            SubHandler(),
-            FallbackHandler(),
-        ]
+        BadGoodCnameHandler(),
+        Cname1Handler(),
+        Cname2Handler(),
+        ExampleHandler(),
+        FooInfoHandler(),
+        NoDataHandler(),
+        NxdomainHandler(),
+        SubHandler(),
     )
+    server.install_response_handler(FallbackHandler())
     server.run()