From 0f87b912aba7e678041632bc9a6d1f7c2d24342c Mon Sep 17 00:00:00 2001
From: Amber Brown <hawkowl@atleastfornow.net>
Date: Thu, 28 Nov 2019 08:54:07 +1100
Subject: [PATCH] Implementation of MSC2314 (#6176)

---
 changelog.d/6176.feature                   |  1 +
 synapse/federation/federation_server.py    | 26 ++++++---
 synapse/federation/transport/server.py     |  6 +-
 sytest-blacklist                           |  6 +-
 tests/federation/test_complexity.py        | 28 +--------
 tests/federation/test_federation_sender.py |  4 +-
 tests/federation/test_federation_server.py | 63 ++++++++++++++++++++
 tests/handlers/test_typing.py              |  3 +
 tests/replication/slave/storage/_base.py   |  3 +
 tests/replication/tcp/streams/_base.py     |  4 ++
 tests/storage/test_roommember.py           | 26 +--------
 tests/unittest.py                          | 68 +++++++++++++++++++++-
 tests/utils.py                             |  1 +
 13 files changed, 174 insertions(+), 65 deletions(-)
 create mode 100644 changelog.d/6176.feature

diff --git a/changelog.d/6176.feature b/changelog.d/6176.feature
new file mode 100644
index 000000000..3c66d689d
--- /dev/null
+++ b/changelog.d/6176.feature
@@ -0,0 +1 @@
+Implement the `/_matrix/federation/unstable/net.atleastfornow/state/<context>` API as drafted in MSC2314.
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index d942d77a7..84d4eca04 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 # Copyright 2015, 2016 OpenMarket Ltd
 # Copyright 2018 New Vector Ltd
+# Copyright 2019 Matrix.org Federation C.I.C
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -73,6 +74,7 @@ class FederationServer(FederationBase):
 
         self.auth = hs.get_auth()
         self.handler = hs.get_handlers().federation_handler
+        self.state = hs.get_state_handler()
 
         self._server_linearizer = Linearizer("fed_server")
         self._transaction_linearizer = Linearizer("fed_txn_handler")
@@ -264,9 +266,6 @@ class FederationServer(FederationBase):
         await self.registry.on_edu(edu_type, origin, content)
 
     async def on_context_state_request(self, origin, room_id, event_id):
-        if not event_id:
-            raise NotImplementedError("Specify an event")
-
         origin_host, _ = parse_server_name(origin)
         await self.check_server_matches_acl(origin_host, room_id)
 
@@ -280,13 +279,18 @@ class FederationServer(FederationBase):
         # - but that's non-trivial to get right, and anyway somewhat defeats
         # the point of the linearizer.
         with (await self._server_linearizer.queue((origin, room_id))):
-            resp = await self._state_resp_cache.wrap(
-                (room_id, event_id),
-                self._on_context_state_request_compute,
-                room_id,
-                event_id,
+            resp = dict(
+                await self._state_resp_cache.wrap(
+                    (room_id, event_id),
+                    self._on_context_state_request_compute,
+                    room_id,
+                    event_id,
+                )
             )
 
+        room_version = await self.store.get_room_version(room_id)
+        resp["room_version"] = room_version
+
         return 200, resp
 
     async def on_state_ids_request(self, origin, room_id, event_id):
@@ -306,7 +310,11 @@ class FederationServer(FederationBase):
         return 200, {"pdu_ids": state_ids, "auth_chain_ids": auth_chain_ids}
 
     async def _on_context_state_request_compute(self, room_id, event_id):
-        pdus = await self.handler.get_state_for_pdu(room_id, event_id)
+        if event_id:
+            pdus = await self.handler.get_state_for_pdu(room_id, event_id)
+        else:
+            pdus = (await self.state.get_current_state(room_id)).values()
+
         auth_chain = await self.store.get_auth_chain([pdu.event_id for pdu in pdus])
 
         return {
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index 09baa9c57..fefc789c8 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -421,7 +421,7 @@ class FederationEventServlet(BaseFederationServlet):
         return await self.handler.on_pdu_request(origin, event_id)
 
 
-class FederationStateServlet(BaseFederationServlet):
+class FederationStateV1Servlet(BaseFederationServlet):
     PATH = "/state/(?P<context>[^/]*)/?"
 
     # This is when someone asks for all data for a given context.
@@ -429,7 +429,7 @@ class FederationStateServlet(BaseFederationServlet):
         return await self.handler.on_context_state_request(
             origin,
             context,
-            parse_string_from_args(query, "event_id", None, required=True),
+            parse_string_from_args(query, "event_id", None, required=False),
         )
 
 
@@ -1360,7 +1360,7 @@ class RoomComplexityServlet(BaseFederationServlet):
 FEDERATION_SERVLET_CLASSES = (
     FederationSendServlet,
     FederationEventServlet,
-    FederationStateServlet,
+    FederationStateV1Servlet,
     FederationStateIdsServlet,
     FederationBackfillServlet,
     FederationQueryServlet,
diff --git a/sytest-blacklist b/sytest-blacklist
index 11785fd43..411cce069 100644
--- a/sytest-blacklist
+++ b/sytest-blacklist
@@ -1,6 +1,6 @@
 # This file serves as a blacklist for SyTest tests that we expect will fail in
 # Synapse.
-# 
+#
 # Each line of this file is scanned by sytest during a run and if the line
 # exactly matches the name of a test, it will be marked as "expected fail",
 # meaning the test will still run, but failure will not mark the entire test
@@ -29,3 +29,7 @@ Enabling an unknown default rule fails with 404
 
 # Blacklisted due to https://github.com/matrix-org/synapse/issues/1663
 New federated private chats get full presence information (SYN-115)
+
+# Blacklisted due to https://github.com/matrix-org/matrix-doc/pull/2314 removing
+# this requirement from the spec
+Inbound federation of state requires event_id as a mandatory paramater
diff --git a/tests/federation/test_complexity.py b/tests/federation/test_complexity.py
index 51714a2b0..24fa8dbb4 100644
--- a/tests/federation/test_complexity.py
+++ b/tests/federation/test_complexity.py
@@ -18,17 +18,14 @@ from mock import Mock
 from twisted.internet import defer
 
 from synapse.api.errors import Codes, SynapseError
-from synapse.config.ratelimiting import FederationRateLimitConfig
-from synapse.federation.transport import server
 from synapse.rest import admin
 from synapse.rest.client.v1 import login, room
 from synapse.types import UserID
-from synapse.util.ratelimitutils import FederationRateLimiter
 
 from tests import unittest
 
 
-class RoomComplexityTests(unittest.HomeserverTestCase):
+class RoomComplexityTests(unittest.FederatingHomeserverTestCase):
 
     servlets = [
         admin.register_servlets,
@@ -41,25 +38,6 @@ class RoomComplexityTests(unittest.HomeserverTestCase):
         config["limit_remote_rooms"] = {"enabled": True, "complexity": 0.05}
         return config
 
-    def prepare(self, reactor, clock, homeserver):
-        class Authenticator(object):
-            def authenticate_request(self, request, content):
-                return defer.succeed("otherserver.nottld")
-
-        ratelimiter = FederationRateLimiter(
-            clock,
-            FederationRateLimitConfig(
-                window_size=1,
-                sleep_limit=1,
-                sleep_msec=1,
-                reject_limit=1000,
-                concurrent_requests=1000,
-            ),
-        )
-        server.register_servlets(
-            homeserver, self.resource, Authenticator(), ratelimiter
-        )
-
     def test_complexity_simple(self):
 
         u1 = self.register_user("u1", "pass")
@@ -105,7 +83,7 @@ class RoomComplexityTests(unittest.HomeserverTestCase):
 
         d = handler._remote_join(
             None,
-            ["otherserver.example"],
+            ["other.example.com"],
             "roomid",
             UserID.from_string(u1),
             {"membership": "join"},
@@ -146,7 +124,7 @@ class RoomComplexityTests(unittest.HomeserverTestCase):
 
         d = handler._remote_join(
             None,
-            ["otherserver.example"],
+            ["other.example.com"],
             room_1,
             UserID.from_string(u1),
             {"membership": "join"},
diff --git a/tests/federation/test_federation_sender.py b/tests/federation/test_federation_sender.py
index cce8d8c6d..d456267b8 100644
--- a/tests/federation/test_federation_sender.py
+++ b/tests/federation/test_federation_sender.py
@@ -19,7 +19,7 @@ from twisted.internet import defer
 
 from synapse.types import ReadReceipt
 
-from tests.unittest import HomeserverTestCase
+from tests.unittest import HomeserverTestCase, override_config
 
 
 class FederationSenderTestCases(HomeserverTestCase):
@@ -29,6 +29,7 @@ class FederationSenderTestCases(HomeserverTestCase):
             federation_transport_client=Mock(spec=["send_transaction"]),
         )
 
+    @override_config({"send_federation": True})
     def test_send_receipts(self):
         mock_state_handler = self.hs.get_state_handler()
         mock_state_handler.get_current_hosts_in_room.return_value = ["test", "host2"]
@@ -69,6 +70,7 @@ class FederationSenderTestCases(HomeserverTestCase):
             ],
         )
 
+    @override_config({"send_federation": True})
     def test_send_receipts_with_backoff(self):
         """Send two receipts in quick succession; the second should be flushed, but
         only after 20ms"""
diff --git a/tests/federation/test_federation_server.py b/tests/federation/test_federation_server.py
index b08be451a..1ec8c4090 100644
--- a/tests/federation/test_federation_server.py
+++ b/tests/federation/test_federation_server.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2018 New Vector Ltd
+# Copyright 2019 Matrix.org Federation C.I.C
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -16,6 +17,8 @@ import logging
 
 from synapse.events import FrozenEvent
 from synapse.federation.federation_server import server_matches_acl_event
+from synapse.rest import admin
+from synapse.rest.client.v1 import login, room
 
 from tests import unittest
 
@@ -41,6 +44,66 @@ class ServerACLsTestCase(unittest.TestCase):
         self.assertTrue(server_matches_acl_event("1:2:3:4", e))
 
 
+class StateQueryTests(unittest.FederatingHomeserverTestCase):
+
+    servlets = [
+        admin.register_servlets,
+        room.register_servlets,
+        login.register_servlets,
+    ]
+
+    def test_without_event_id(self):
+        """
+        Querying v1/state/<room_id> without an event ID will return the current
+        known state.
+        """
+        u1 = self.register_user("u1", "pass")
+        u1_token = self.login("u1", "pass")
+
+        room_1 = self.helper.create_room_as(u1, tok=u1_token)
+        self.inject_room_member(room_1, "@user:other.example.com", "join")
+
+        request, channel = self.make_request(
+            "GET", "/_matrix/federation/v1/state/%s" % (room_1,)
+        )
+        self.render(request)
+        self.assertEquals(200, channel.code, channel.result)
+
+        self.assertEqual(
+            channel.json_body["room_version"],
+            self.hs.config.default_room_version.identifier,
+        )
+
+        members = set(
+            map(
+                lambda x: x["state_key"],
+                filter(
+                    lambda x: x["type"] == "m.room.member", channel.json_body["pdus"]
+                ),
+            )
+        )
+
+        self.assertEqual(members, set(["@user:other.example.com", u1]))
+        self.assertEqual(len(channel.json_body["pdus"]), 6)
+
+    def test_needs_to_be_in_room(self):
+        """
+        Querying v1/state/<room_id> requires the server
+        be in the room to provide data.
+        """
+        u1 = self.register_user("u1", "pass")
+        u1_token = self.login("u1", "pass")
+
+        room_1 = self.helper.create_room_as(u1, tok=u1_token)
+
+        request, channel = self.make_request(
+            "GET", "/_matrix/federation/v1/state/%s" % (room_1,)
+        )
+        self.render(request)
+        self.assertEquals(403, channel.code, channel.result)
+        self.assertEqual(channel.json_body["errcode"], "M_FORBIDDEN")
+
+
 def _create_acl_event(content):
     return FrozenEvent(
         {
diff --git a/tests/handlers/test_typing.py b/tests/handlers/test_typing.py
index 5ec568f4e..f6d866028 100644
--- a/tests/handlers/test_typing.py
+++ b/tests/handlers/test_typing.py
@@ -24,6 +24,7 @@ from synapse.api.errors import AuthError
 from synapse.types import UserID
 
 from tests import unittest
+from tests.unittest import override_config
 from tests.utils import register_federation_servlets
 
 # Some local users to test with
@@ -174,6 +175,7 @@ class TypingNotificationsTestCase(unittest.HomeserverTestCase):
             ],
         )
 
+    @override_config({"send_federation": True})
     def test_started_typing_remote_send(self):
         self.room_members = [U_APPLE, U_ONION]
 
@@ -237,6 +239,7 @@ class TypingNotificationsTestCase(unittest.HomeserverTestCase):
             ],
         )
 
+    @override_config({"send_federation": True})
     def test_stopped_typing(self):
         self.room_members = [U_APPLE, U_BANANA, U_ONION]
 
diff --git a/tests/replication/slave/storage/_base.py b/tests/replication/slave/storage/_base.py
index 4f924ce45..e7472e3a9 100644
--- a/tests/replication/slave/storage/_base.py
+++ b/tests/replication/slave/storage/_base.py
@@ -48,7 +48,10 @@ class BaseSlavedStoreTestCase(unittest.HomeserverTestCase):
         server_factory = ReplicationStreamProtocolFactory(self.hs)
         self.streamer = server_factory.streamer
 
+        handler_factory = Mock()
         self.replication_handler = ReplicationClientHandler(self.slaved_store)
+        self.replication_handler.factory = handler_factory
+
         client_factory = ReplicationClientFactory(
             self.hs, "client_name", self.replication_handler
         )
diff --git a/tests/replication/tcp/streams/_base.py b/tests/replication/tcp/streams/_base.py
index ce3835ae6..1d14e7725 100644
--- a/tests/replication/tcp/streams/_base.py
+++ b/tests/replication/tcp/streams/_base.py
@@ -12,6 +12,8 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+from mock import Mock
+
 from synapse.replication.tcp.commands import ReplicateCommand
 from synapse.replication.tcp.protocol import ClientReplicationStreamProtocol
 from synapse.replication.tcp.resource import ReplicationStreamProtocolFactory
@@ -30,7 +32,9 @@ class BaseStreamTestCase(unittest.HomeserverTestCase):
         server = server_factory.buildProtocol(None)
 
         # build a replication client, with a dummy handler
+        handler_factory = Mock()
         self.test_handler = TestReplicationClientHandler()
+        self.test_handler.factory = handler_factory
         self.client = ClientReplicationStreamProtocol(
             "client", "test", clock, self.test_handler
         )
diff --git a/tests/storage/test_roommember.py b/tests/storage/test_roommember.py
index 9ddd17f73..105a0c2b0 100644
--- a/tests/storage/test_roommember.py
+++ b/tests/storage/test_roommember.py
@@ -16,8 +16,7 @@
 
 from unittest.mock import Mock
 
-from synapse.api.constants import EventTypes, Membership
-from synapse.api.room_versions import RoomVersions
+from synapse.api.constants import Membership
 from synapse.rest.admin import register_servlets_for_client_rest_resource
 from synapse.rest.client.v1 import login, room
 from synapse.types import Requester, UserID
@@ -44,9 +43,6 @@ class RoomMemberStoreTestCase(unittest.HomeserverTestCase):
         # We can't test the RoomMemberStore on its own without the other event
         # storage logic
         self.store = hs.get_datastore()
-        self.storage = hs.get_storage()
-        self.event_builder_factory = hs.get_event_builder_factory()
-        self.event_creation_handler = hs.get_event_creation_handler()
 
         self.u_alice = self.register_user("alice", "pass")
         self.t_alice = self.login("alice", "pass")
@@ -55,26 +51,6 @@ class RoomMemberStoreTestCase(unittest.HomeserverTestCase):
         # User elsewhere on another host
         self.u_charlie = UserID.from_string("@charlie:elsewhere")
 
-    def inject_room_member(self, room, user, membership, replaces_state=None):
-        builder = self.event_builder_factory.for_room_version(
-            RoomVersions.V1,
-            {
-                "type": EventTypes.Member,
-                "sender": user,
-                "state_key": user,
-                "room_id": room,
-                "content": {"membership": membership},
-            },
-        )
-
-        event, context = self.get_success(
-            self.event_creation_handler.create_new_client_event(builder)
-        )
-
-        self.get_success(self.storage.persistence.persist_event(event, context))
-
-        return event
-
     def test_one_member(self):
 
         # Alice creates the room, and is automatically joined
diff --git a/tests/unittest.py b/tests/unittest.py
index 561cebc22..31997a0f3 100644
--- a/tests/unittest.py
+++ b/tests/unittest.py
@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 # Copyright 2014-2016 OpenMarket Ltd
 # Copyright 2018 New Vector
+# Copyright 2019 Matrix.org Federation C.I.C
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -13,6 +14,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
 import gc
 import hashlib
 import hmac
@@ -27,13 +29,17 @@ from twisted.internet.defer import Deferred, succeed
 from twisted.python.threadpool import ThreadPool
 from twisted.trial import unittest
 
-from synapse.api.constants import EventTypes
+from synapse.api.constants import EventTypes, Membership
+from synapse.api.room_versions import KNOWN_ROOM_VERSIONS
 from synapse.config.homeserver import HomeServerConfig
+from synapse.config.ratelimiting import FederationRateLimitConfig
+from synapse.federation.transport import server as federation_server
 from synapse.http.server import JsonResource
 from synapse.http.site import SynapseRequest
 from synapse.logging.context import LoggingContext
 from synapse.server import HomeServer
 from synapse.types import Requester, UserID, create_requester
+from synapse.util.ratelimitutils import FederationRateLimiter
 
 from tests.server import get_clock, make_request, render, setup_test_homeserver
 from tests.test_utils.logging_setup import setup_logging
@@ -559,6 +565,66 @@ class HomeserverTestCase(TestCase):
         self.render(request)
         self.assertEqual(channel.code, 403, channel.result)
 
+    def inject_room_member(self, room: str, user: str, membership: Membership) -> None:
+        """
+        Inject a membership event into a room.
+
+        Args:
+            room: Room ID to inject the event into.
+            user: MXID of the user to inject the membership for.
+            membership: The membership type.
+        """
+        event_builder_factory = self.hs.get_event_builder_factory()
+        event_creation_handler = self.hs.get_event_creation_handler()
+
+        room_version = self.get_success(self.hs.get_datastore().get_room_version(room))
+
+        builder = event_builder_factory.for_room_version(
+            KNOWN_ROOM_VERSIONS[room_version],
+            {
+                "type": EventTypes.Member,
+                "sender": user,
+                "state_key": user,
+                "room_id": room,
+                "content": {"membership": membership},
+            },
+        )
+
+        event, context = self.get_success(
+            event_creation_handler.create_new_client_event(builder)
+        )
+
+        self.get_success(
+            self.hs.get_storage().persistence.persist_event(event, context)
+        )
+
+
+class FederatingHomeserverTestCase(HomeserverTestCase):
+    """
+    A federating homeserver that authenticates incoming requests as `other.example.com`.
+    """
+
+    def prepare(self, reactor, clock, homeserver):
+        class Authenticator(object):
+            def authenticate_request(self, request, content):
+                return succeed("other.example.com")
+
+        ratelimiter = FederationRateLimiter(
+            clock,
+            FederationRateLimitConfig(
+                window_size=1,
+                sleep_limit=1,
+                sleep_msec=1,
+                reject_limit=1000,
+                concurrent_requests=1000,
+            ),
+        )
+        federation_server.register_servlets(
+            homeserver, self.resource, Authenticator(), ratelimiter
+        )
+
+        return super().prepare(reactor, clock, homeserver)
+
 
 def override_config(extra_config):
     """A decorator which can be applied to test functions to give additional HS config
diff --git a/tests/utils.py b/tests/utils.py
index 7dc9bdc50..de2ac1ed3 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -109,6 +109,7 @@ def default_config(name, parse=False):
     """
     config_dict = {
         "server_name": name,
+        "send_federation": False,
         "media_store_path": "media",
         "uploads_path": "uploads",
         # the test signing key is just an arbitrary ed25519 key to keep the config