252 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			Python
		
	
	
			
		
		
	
	
			252 lines
		
	
	
		
			8.9 KiB
		
	
	
	
		
			Python
		
	
	
| #  Copyright 2021 The Matrix.org Foundation C.I.C.
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| #
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| #  Licensed under the Apache License, Version 2.0 (the "License");
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| #  you may not use this file except in compliance with the License.
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| #  You may obtain a copy of the License at
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| #
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| #      http://www.apache.org/licenses/LICENSE-2.0
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| #
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| #  Unless required by applicable law or agreed to in writing, software
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| #  distributed under the License is distributed on an "AS IS" BASIS,
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| #  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| #  See the License for the specific language governing permissions and
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| #  limitations under the License.
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| 
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| from io import BytesIO
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| from typing import Tuple, Union
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| from unittest.mock import Mock
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| 
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| from netaddr import IPSet
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| 
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| from twisted.internet.defer import Deferred
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| from twisted.internet.error import DNSLookupError
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| from twisted.python.failure import Failure
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| from twisted.test.proto_helpers import AccumulatingProtocol
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| from twisted.web.client import Agent, ResponseDone
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| from twisted.web.iweb import UNKNOWN_LENGTH
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| 
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| from synapse.api.errors import SynapseError
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| from synapse.http.client import (
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|     BlocklistingAgentWrapper,
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|     BlocklistingReactorWrapper,
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|     BodyExceededMaxSize,
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|     _DiscardBodyWithMaxSizeProtocol,
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|     read_body_with_max_size,
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| )
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| 
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| from tests.server import FakeTransport, get_clock
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| from tests.unittest import TestCase
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| 
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| 
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| class ReadBodyWithMaxSizeTests(TestCase):
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|     def _build_response(
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|         self, length: Union[int, str] = UNKNOWN_LENGTH
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|     ) -> Tuple[BytesIO, "Deferred[int]", _DiscardBodyWithMaxSizeProtocol]:
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|         """Start reading the body, returns the response, result and proto"""
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|         response = Mock(length=length)
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|         result = BytesIO()
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|         deferred = read_body_with_max_size(response, result, 6)
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| 
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|         # Fish the protocol out of the response.
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|         protocol = response.deliverBody.call_args[0][0]
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|         protocol.transport = Mock()
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| 
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|         return result, deferred, protocol
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| 
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|     def _assert_error(
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|         self, deferred: "Deferred[int]", protocol: _DiscardBodyWithMaxSizeProtocol
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|     ) -> None:
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|         """Ensure that the expected error is received."""
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|         assert isinstance(deferred.result, Failure)
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|         self.assertIsInstance(deferred.result.value, BodyExceededMaxSize)
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|         assert protocol.transport is not None
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|         # type-ignore: presumably abortConnection has been replaced with a Mock.
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|         protocol.transport.abortConnection.assert_called_once()  # type: ignore[attr-defined]
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| 
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|     def _cleanup_error(self, deferred: "Deferred[int]") -> None:
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|         """Ensure that the error in the Deferred is handled gracefully."""
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|         called = [False]
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| 
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|         def errback(f: Failure) -> None:
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|             called[0] = True
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| 
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|         deferred.addErrback(errback)
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|         self.assertTrue(called[0])
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| 
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|     def test_no_error(self) -> None:
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|         """A response that is NOT too large."""
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|         result, deferred, protocol = self._build_response()
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| 
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|         # Start sending data.
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|         protocol.dataReceived(b"12345")
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|         # Close the connection.
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|         protocol.connectionLost(Failure(ResponseDone()))
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| 
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|         self.assertEqual(result.getvalue(), b"12345")
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|         self.assertEqual(deferred.result, 5)
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| 
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|     def test_too_large(self) -> None:
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|         """A response which is too large raises an exception."""
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|         result, deferred, protocol = self._build_response()
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| 
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|         # Start sending data.
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|         protocol.dataReceived(b"1234567890")
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| 
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|         self.assertEqual(result.getvalue(), b"1234567890")
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|         self._assert_error(deferred, protocol)
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|         self._cleanup_error(deferred)
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| 
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|     def test_multiple_packets(self) -> None:
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|         """Data should be accumulated through mutliple packets."""
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|         result, deferred, protocol = self._build_response()
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| 
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|         # Start sending data.
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|         protocol.dataReceived(b"12")
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|         protocol.dataReceived(b"34")
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|         # Close the connection.
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|         protocol.connectionLost(Failure(ResponseDone()))
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| 
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|         self.assertEqual(result.getvalue(), b"1234")
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|         self.assertEqual(deferred.result, 4)
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| 
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|     def test_additional_data(self) -> None:
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|         """A connection can receive data after being closed."""
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|         result, deferred, protocol = self._build_response()
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| 
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|         # Start sending data.
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|         protocol.dataReceived(b"1234567890")
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|         self._assert_error(deferred, protocol)
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| 
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|         # More data might have come in.
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|         protocol.dataReceived(b"1234567890")
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| 
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|         self.assertEqual(result.getvalue(), b"1234567890")
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|         self._assert_error(deferred, protocol)
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|         self._cleanup_error(deferred)
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| 
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|     def test_content_length(self) -> None:
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|         """The body shouldn't be read (at all) if the Content-Length header is too large."""
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|         result, deferred, protocol = self._build_response(length=10)
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| 
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|         # Deferred shouldn't be called yet.
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|         self.assertFalse(deferred.called)
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| 
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|         # Start sending data.
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|         protocol.dataReceived(b"12345")
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|         self._assert_error(deferred, protocol)
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|         self._cleanup_error(deferred)
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| 
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|         # The data is never consumed.
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|         self.assertEqual(result.getvalue(), b"")
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| 
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| 
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| class BlocklistingAgentTest(TestCase):
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|     def setUp(self) -> None:
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|         self.reactor, self.clock = get_clock()
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| 
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|         self.safe_domain, self.safe_ip = b"safe.test", b"1.2.3.4"
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|         self.unsafe_domain, self.unsafe_ip = b"danger.test", b"5.6.7.8"
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|         self.allowed_domain, self.allowed_ip = b"allowed.test", b"5.1.1.1"
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| 
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|         # Configure the reactor's DNS resolver.
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|         for domain, ip in (
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|             (self.safe_domain, self.safe_ip),
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|             (self.unsafe_domain, self.unsafe_ip),
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|             (self.allowed_domain, self.allowed_ip),
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|         ):
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|             self.reactor.lookups[domain.decode()] = ip.decode()
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|             self.reactor.lookups[ip.decode()] = ip.decode()
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| 
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|         self.ip_allowlist = IPSet([self.allowed_ip.decode()])
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|         self.ip_blocklist = IPSet(["5.0.0.0/8"])
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| 
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|     def test_reactor(self) -> None:
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|         """Apply the blocklisting reactor and ensure it properly blocks connections to particular domains and IPs."""
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|         agent = Agent(
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|             BlocklistingReactorWrapper(
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|                 self.reactor,
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|                 ip_allowlist=self.ip_allowlist,
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|                 ip_blocklist=self.ip_blocklist,
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|             ),
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|         )
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| 
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|         # The unsafe domains and IPs should be rejected.
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|         for domain in (self.unsafe_domain, self.unsafe_ip):
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|             self.failureResultOf(
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|                 agent.request(b"GET", b"http://" + domain), DNSLookupError
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|             )
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| 
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|         # The safe domains IPs should be accepted.
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|         for domain in (
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|             self.safe_domain,
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|             self.allowed_domain,
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|             self.safe_ip,
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|             self.allowed_ip,
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|         ):
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|             d = agent.request(b"GET", b"http://" + domain)
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| 
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|             # Grab the latest TCP connection.
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|             (
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|                 host,
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|                 port,
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|                 client_factory,
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|                 _timeout,
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|                 _bindAddress,
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|             ) = self.reactor.tcpClients[-1]
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| 
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|             # Make the connection and pump data through it.
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|             client = client_factory.buildProtocol(None)
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|             server = AccumulatingProtocol()
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|             server.makeConnection(FakeTransport(client, self.reactor))
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|             client.makeConnection(FakeTransport(server, self.reactor))
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|             client.dataReceived(
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|                 b"HTTP/1.0 200 OK\r\nContent-Length: 0\r\nContent-Type: text/html\r\n\r\n"
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|             )
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| 
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|             response = self.successResultOf(d)
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|             self.assertEqual(response.code, 200)
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| 
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|     def test_agent(self) -> None:
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|         """Apply the blocklisting agent and ensure it properly blocks connections to particular IPs."""
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|         agent = BlocklistingAgentWrapper(
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|             Agent(self.reactor),
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|             ip_blocklist=self.ip_blocklist,
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|             ip_allowlist=self.ip_allowlist,
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|         )
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| 
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|         # The unsafe IPs should be rejected.
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|         self.failureResultOf(
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|             agent.request(b"GET", b"http://" + self.unsafe_ip), SynapseError
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|         )
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| 
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|         # The safe and unsafe domains and safe IPs should be accepted.
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|         for domain in (
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|             self.safe_domain,
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|             self.unsafe_domain,
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|             self.allowed_domain,
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|             self.safe_ip,
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|             self.allowed_ip,
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|         ):
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|             d = agent.request(b"GET", b"http://" + domain)
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| 
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|             # Grab the latest TCP connection.
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|             (
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|                 host,
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|                 port,
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|                 client_factory,
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|                 _timeout,
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|                 _bindAddress,
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|             ) = self.reactor.tcpClients[-1]
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| 
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|             # Make the connection and pump data through it.
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|             client = client_factory.buildProtocol(None)
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|             server = AccumulatingProtocol()
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|             server.makeConnection(FakeTransport(client, self.reactor))
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|             client.makeConnection(FakeTransport(server, self.reactor))
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|             client.dataReceived(
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|                 b"HTTP/1.0 200 OK\r\nContent-Length: 0\r\nContent-Type: text/html\r\n\r\n"
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|             )
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| 
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|             response = self.successResultOf(d)
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|             self.assertEqual(response.code, 200)
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