Merge pull request #6349 from matrix-org/babolivier/msc1802

Implement v2 APIs for send_join and send_leave

5 files changed, 141 insertions, 28 deletions

diff --git a/changelog.d/6349.feature b/changelog.d/6349.feature
new file mode 100644
index 0000000000..56c4fbf78e
--- /dev/null
+++ b/changelog.d/6349.feature
@@ -0,0 +1 @@
+Implement v2 APIs for the `send_join` and `send_leave` federation endpoints (as described in [MSC1802](https://github.com/matrix-org/matrix-doc/pull/1802)).
diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index d396e6564f..af652a7659 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -526,13 +526,7 @@ class FederationClient(FederationBase):
 
         @defer.inlineCallbacks
         def send_request(destination):
-            time_now = self._clock.time_msec()
-            _, content = yield self.transport_layer.send_join(
-                destination=destination,
-                room_id=pdu.room_id,
-                event_id=pdu.event_id,
-                content=pdu.get_pdu_json(time_now),
-            )
+            content = yield self._do_send_join(destination, pdu)
 
             logger.debug("Got content: %s", content)
 
@@ -600,6 +594,44 @@ class FederationClient(FederationBase):
         return self._try_destination_list("send_join", destinations, send_request)
 
     @defer.inlineCallbacks
+    def _do_send_join(self, destination, pdu):
+        time_now = self._clock.time_msec()
+
+        try:
+            content = yield self.transport_layer.send_join_v2(
+                destination=destination,
+                room_id=pdu.room_id,
+                event_id=pdu.event_id,
+                content=pdu.get_pdu_json(time_now),
+            )
+
+            return content
+        except HttpResponseException as e:
+            if e.code in [400, 404]:
+                err = e.to_synapse_error()
+
+                # If we receive an error response that isn't a generic error, or an
+                # unrecognised endpoint error, we  assume that the remote understands
+                # the v2 invite API and this is a legitimate error.
+                if err.errcode not in [Codes.UNKNOWN, Codes.UNRECOGNIZED]:
+                    raise err
+            else:
+                raise e.to_synapse_error()
+
+        logger.debug("Couldn't send_join with the v2 API, falling back to the v1 API")
+
+        resp = yield self.transport_layer.send_join_v1(
+            destination=destination,
+            room_id=pdu.room_id,
+            event_id=pdu.event_id,
+            content=pdu.get_pdu_json(time_now),
+        )
+
+        # We expect the v1 API to respond with [200, content], so we only return the
+        # content.
+        return resp[1]
+
+    @defer.inlineCallbacks
     def send_invite(self, destination, room_id, event_id, pdu):
         room_version = yield self.store.get_room_version(room_id)
 
@@ -708,18 +740,50 @@ class FederationClient(FederationBase):
 
         @defer.inlineCallbacks
         def send_request(destination):
-            time_now = self._clock.time_msec()
-            _, content = yield self.transport_layer.send_leave(
+            content = yield self._do_send_leave(destination, pdu)
+
+            logger.debug("Got content: %s", content)
+            return None
+
+        return self._try_destination_list("send_leave", destinations, send_request)
+
+    @defer.inlineCallbacks
+    def _do_send_leave(self, destination, pdu):
+        time_now = self._clock.time_msec()
+
+        try:
+            content = yield self.transport_layer.send_leave_v2(
                 destination=destination,
                 room_id=pdu.room_id,
                 event_id=pdu.event_id,
                 content=pdu.get_pdu_json(time_now),
             )
 
-            logger.debug("Got content: %s", content)
-            return None
+            return content
+        except HttpResponseException as e:
+            if e.code in [400, 404]:
+                err = e.to_synapse_error()
 
-        return self._try_destination_list("send_leave", destinations, send_request)
+                # If we receive an error response that isn't a generic error, or an
+                # unrecognised endpoint error, we  assume that the remote understands
+                # the v2 invite API and this is a legitimate error.
+                if err.errcode not in [Codes.UNKNOWN, Codes.UNRECOGNIZED]:
+                    raise err
+            else:
+                raise e.to_synapse_error()
+
+        logger.debug("Couldn't send_leave with the v2 API, falling back to the v1 API")
+
+        resp = yield self.transport_layer.send_leave_v1(
+            destination=destination,
+            room_id=pdu.room_id,
+            event_id=pdu.event_id,
+            content=pdu.get_pdu_json(time_now),
+        )
+
+        # We expect the v1 API to respond with [200, content], so we only return the
+        # content.
+        return resp[1]
 
     def get_public_rooms(
         self,
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 84d4eca041..d7ce333822 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -384,15 +384,10 @@ class FederationServer(FederationBase):
 
         res_pdus = await self.handler.on_send_join_request(origin, pdu)
         time_now = self._clock.time_msec()
-        return (
-            200,
-            {
-                "state": [p.get_pdu_json(time_now) for p in res_pdus["state"]],
-                "auth_chain": [
-                    p.get_pdu_json(time_now) for p in res_pdus["auth_chain"]
-                ],
-            },
-        )
+        return {
+            "state": [p.get_pdu_json(time_now) for p in res_pdus["state"]],
+            "auth_chain": [p.get_pdu_json(time_now) for p in res_pdus["auth_chain"]],
+        }
 
     async def on_make_leave_request(self, origin, room_id, user_id):
         origin_host, _ = parse_server_name(origin)
@@ -419,7 +414,7 @@ class FederationServer(FederationBase):
         pdu = await self._check_sigs_and_hash(room_version, pdu)
 
         await self.handler.on_send_leave_request(origin, pdu)
-        return 200, {}
+        return {}
 
     async def on_event_auth(self, origin, room_id, event_id):
         with (await self._server_linearizer.queue((origin, room_id))):
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index 46dba84cac..198257414b 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -243,7 +243,7 @@ class TransportLayerClient(object):
 
     @defer.inlineCallbacks
     @log_function
-    def send_join(self, destination, room_id, event_id, content):
+    def send_join_v1(self, destination, room_id, event_id, content):
         path = _create_v1_path("/send_join/%s/%s", room_id, event_id)
 
         response = yield self.client.put_json(
@@ -254,7 +254,18 @@ class TransportLayerClient(object):
 
     @defer.inlineCallbacks
     @log_function
-    def send_leave(self, destination, room_id, event_id, content):
+    def send_join_v2(self, destination, room_id, event_id, content):
+        path = _create_v2_path("/send_join/%s/%s", room_id, event_id)
+
+        response = yield self.client.put_json(
+            destination=destination, path=path, data=content
+        )
+
+        return response
+
+    @defer.inlineCallbacks
+    @log_function
+    def send_leave_v1(self, destination, room_id, event_id, content):
         path = _create_v1_path("/send_leave/%s/%s", room_id, event_id)
 
         response = yield self.client.put_json(
@@ -272,6 +283,24 @@ class TransportLayerClient(object):
 
     @defer.inlineCallbacks
     @log_function
+    def send_leave_v2(self, destination, room_id, event_id, content):
+        path = _create_v2_path("/send_leave/%s/%s", room_id, event_id)
+
+        response = yield self.client.put_json(
+            destination=destination,
+            path=path,
+            data=content,
+            # we want to do our best to send this through. The problem is
+            # that if it fails, we won't retry it later, so if the remote
+            # server was just having a momentary blip, the room will be out of
+            # sync.
+            ignore_backoff=True,
+        )
+
+        return response
+
+    @defer.inlineCallbacks
+    @log_function
     def send_invite_v1(self, destination, room_id, event_id, content):
         path = _create_v1_path("/invite/%s/%s", room_id, event_id)
 
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index fefc789c85..b4cbf23394 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -506,11 +506,21 @@ class FederationMakeLeaveServlet(BaseFederationServlet):
         return 200, content
 
 
-class FederationSendLeaveServlet(BaseFederationServlet):
+class FederationV1SendLeaveServlet(BaseFederationServlet):
     PATH = "/send_leave/(?P<room_id>[^/]*)/(?P<event_id>[^/]*)"
 
     async def on_PUT(self, origin, content, query, room_id, event_id):
         content = await self.handler.on_send_leave_request(origin, content, room_id)
+        return 200, (200, content)
+
+
+class FederationV2SendLeaveServlet(BaseFederationServlet):
+    PATH = "/send_leave/(?P<room_id>[^/]*)/(?P<event_id>[^/]*)"
+
+    PREFIX = FEDERATION_V2_PREFIX
+
+    async def on_PUT(self, origin, content, query, room_id, event_id):
+        content = await self.handler.on_send_leave_request(origin, content, room_id)
         return 200, content
 
 
@@ -521,9 +531,21 @@ class FederationEventAuthServlet(BaseFederationServlet):
         return await self.handler.on_event_auth(origin, context, event_id)
 
 
-class FederationSendJoinServlet(BaseFederationServlet):
+class FederationV1SendJoinServlet(BaseFederationServlet):
+    PATH = "/send_join/(?P<context>[^/]*)/(?P<event_id>[^/]*)"
+
+    async def on_PUT(self, origin, content, query, context, event_id):
+        # TODO(paul): assert that context/event_id parsed from path actually
+        #   match those given in content
+        content = await self.handler.on_send_join_request(origin, content, context)
+        return 200, (200, content)
+
+
+class FederationV2SendJoinServlet(BaseFederationServlet):
     PATH = "/send_join/(?P<context>[^/]*)/(?P<event_id>[^/]*)"
 
+    PREFIX = FEDERATION_V2_PREFIX
+
     async def on_PUT(self, origin, content, query, context, event_id):
         # TODO(paul): assert that context/event_id parsed from path actually
         #   match those given in content
@@ -1367,8 +1389,10 @@ FEDERATION_SERVLET_CLASSES = (
     FederationMakeJoinServlet,
     FederationMakeLeaveServlet,
     FederationEventServlet,
-    FederationSendJoinServlet,
-    FederationSendLeaveServlet,
+    FederationV1SendJoinServlet,
+    FederationV2SendJoinServlet,
+    FederationV1SendLeaveServlet,
+    FederationV2SendLeaveServlet,
     FederationV1InviteServlet,
     FederationV2InviteServlet,
     FederationQueryAuthServlet,