Allow rejecting invites

This is done by using the same /leave flow as you would use if you had
already accepted the invite and wanted to leave.

4 files changed, 117 insertions, 8 deletions

diff --git a/synapse/federation/federation_client.py b/synapse/federation/federation_client.py
index f5b430e046..723f571284 100644
--- a/synapse/federation/federation_client.py
+++ b/synapse/federation/federation_client.py
@@ -17,6 +17,7 @@
 from twisted.internet import defer
 
 from .federation_base import FederationBase
+from synapse.api.constants import Membership
 from .units import Edu
 
 from synapse.api.errors import (
@@ -357,7 +358,34 @@ class FederationClient(FederationBase):
         defer.returnValue(signed_auth)
 
     @defer.inlineCallbacks
-    def make_join(self, destinations, room_id, user_id, content):
+    def make_membership_event(self, destinations, room_id, user_id, membership, content):
+        """
+        Creates an m.room.member event, with context, without participating in the room.
+
+        Does so by asking one of the already participating servers to create an
+        event with proper context.
+
+        Note that this does not append any events to any graphs.
+
+        Args:
+            destinations (str): Candidate homeservers which are probably
+                participating in the room.
+            room_id (str): The room in which the event will happen.
+            user_id (str): The user whose membership is being evented.
+            membership (str): The "membership" property of the event. Must be
+                one of "join" or "leave".
+            content (object): Any additional data to put into the content field
+                of the event.
+        Return:
+            A tuple of (origin (str), event (object)) where origin is the remote
+            homeserver which generated the event.
+        """
+        valid_memberships = {Membership.JOIN, Membership.LEAVE}
+        if membership not in valid_memberships:
+            raise RuntimeError(
+                "make_membership_event called with membership='%s', must be one of %s" %
+                (membership, ",".join(valid_memberships))
+            )
         for destination in destinations:
             if destination == self.server_name:
                 continue
@@ -368,13 +396,13 @@ class FederationClient(FederationBase):
                     content["third_party_invite"]
                 )
             try:
-                ret = yield self.transport_layer.make_join(
-                    destination, room_id, user_id, args
+                ret = yield self.transport_layer.make_membership_event(
+                    destination, room_id, user_id, membership, args
                 )
 
                 pdu_dict = ret["event"]
 
-                logger.debug("Got response to make_join: %s", pdu_dict)
+                logger.debug("Got response to make_%s: %s", membership, pdu_dict)
 
                 defer.returnValue(
                     (destination, self.event_from_pdu_json(pdu_dict))
@@ -384,8 +412,8 @@ class FederationClient(FederationBase):
                 raise
             except Exception as e:
                 logger.warn(
-                    "Failed to make_join via %s: %s",
-                    destination, e.message
+                    "Failed to make_%s via %s: %s",
+                    membership, destination, e.message
                 )
 
         raise RuntimeError("Failed to send to any server.")
@@ -492,6 +520,33 @@ class FederationClient(FederationBase):
         defer.returnValue(pdu)
 
     @defer.inlineCallbacks
+    def send_leave(self, destinations, pdu):
+        for destination in destinations:
+            if destination == self.server_name:
+                continue
+
+            try:
+                time_now = self._clock.time_msec()
+                _, content = yield self.transport_layer.send_leave(
+                    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)
+                defer.returnValue(None)
+            except CodeMessageException:
+                raise
+            except Exception as e:
+                logger.exception(
+                    "Failed to send_leave via %s: %s",
+                    destination, e.message
+                )
+
+        raise RuntimeError("Failed to send to any server.")
+
+    @defer.inlineCallbacks
     def query_auth(self, destination, room_id, event_id, local_auth):
         """
         Params:
diff --git a/synapse/federation/federation_server.py b/synapse/federation/federation_server.py
index 7934f740e0..9e2d9ee74c 100644
--- a/synapse/federation/federation_server.py
+++ b/synapse/federation/federation_server.py
@@ -268,6 +268,20 @@ class FederationServer(FederationBase):
         }))
 
     @defer.inlineCallbacks
+    def on_make_leave_request(self, room_id, user_id):
+        pdu = yield self.handler.on_make_leave_request(room_id, user_id)
+        time_now = self._clock.time_msec()
+        defer.returnValue({"event": pdu.get_pdu_json(time_now)})
+
+    @defer.inlineCallbacks
+    def on_send_leave_request(self, origin, content):
+        logger.debug("on_send_leave_request: content: %s", content)
+        pdu = self.event_from_pdu_json(content)
+        logger.debug("on_send_leave_request: pdu sigs: %s", pdu.signatures)
+        yield self.handler.on_send_leave_request(origin, pdu)
+        defer.returnValue((200, {}))
+
+    @defer.inlineCallbacks
     def on_event_auth(self, origin, room_id, event_id):
         time_now = self._clock.time_msec()
         auth_pdus = yield self.handler.on_event_auth(event_id)
diff --git a/synapse/federation/transport/client.py b/synapse/federation/transport/client.py
index ae4195e83a..a81b3c4345 100644
--- a/synapse/federation/transport/client.py
+++ b/synapse/federation/transport/client.py
@@ -14,6 +14,7 @@
 # limitations under the License.
 
 from twisted.internet import defer
+from synapse.api.constants import Membership
 
 from synapse.api.urls import FEDERATION_PREFIX as PREFIX
 from synapse.util.logutils import log_function
@@ -160,8 +161,14 @@ class TransportLayerClient(object):
 
     @defer.inlineCallbacks
     @log_function
-    def make_join(self, destination, room_id, user_id, args={}):
-        path = PREFIX + "/make_join/%s/%s" % (room_id, user_id)
+    def make_membership_event(self, destination, room_id, user_id, membership, args={}):
+        valid_memberships = {Membership.JOIN, Membership.LEAVE}
+        if membership not in valid_memberships:
+            raise RuntimeError(
+                "make_membership_event called with membership='%s', must be one of %s" %
+                (membership, ",".join(valid_memberships))
+            )
+        path = PREFIX + "/make_%s/%s/%s" % (membership, room_id, user_id)
 
         content = yield self.client.get_json(
             destination=destination,
@@ -187,6 +194,19 @@ class TransportLayerClient(object):
 
     @defer.inlineCallbacks
     @log_function
+    def send_leave(self, destination, room_id, event_id, content):
+        path = PREFIX + "/send_leave/%s/%s" % (room_id, event_id)
+
+        response = yield self.client.put_json(
+            destination=destination,
+            path=path,
+            data=content,
+        )
+
+        defer.returnValue(response)
+
+    @defer.inlineCallbacks
+    @log_function
     def send_invite(self, destination, room_id, event_id, content):
         path = PREFIX + "/invite/%s/%s" % (room_id, event_id)
 
diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index 6e394f039e..8184159210 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -296,6 +296,24 @@ class FederationMakeJoinServlet(BaseFederationServlet):
         defer.returnValue((200, content))
 
 
+class FederationMakeLeaveServlet(BaseFederationServlet):
+    PATH = "/make_leave/([^/]*)/([^/]*)"
+
+    @defer.inlineCallbacks
+    def on_GET(self, origin, content, query, context, user_id):
+        content = yield self.handler.on_make_leave_request(context, user_id)
+        defer.returnValue((200, content))
+
+
+class FederationSendLeaveServlet(BaseFederationServlet):
+    PATH = "/send_leave/([^/]*)/([^/]*)"
+
+    @defer.inlineCallbacks
+    def on_PUT(self, origin, content, query, room_id, txid):
+        content = yield self.handler.on_send_leave_request(origin, content)
+        defer.returnValue((200, content))
+
+
 class FederationEventAuthServlet(BaseFederationServlet):
     PATH = "/event_auth/([^/]*)/([^/]*)"
 
@@ -385,8 +403,10 @@ SERVLET_CLASSES = (
     FederationBackfillServlet,
     FederationQueryServlet,
     FederationMakeJoinServlet,
+    FederationMakeLeaveServlet,
     FederationEventServlet,
     FederationSendJoinServlet,
+    FederationSendLeaveServlet,
     FederationInviteServlet,
     FederationQueryAuthServlet,
     FederationGetMissingEventsServlet,