2 files changed, 38 insertions, 3 deletions
diff --git a/synapse/handlers/federation.py b/synapse/handlers/federation.py
index 533b82c783..0dffd44e22 100644
--- a/synapse/handlers/federation.py
+++ b/synapse/handlers/federation.py
@@ -30,7 +30,12 @@ from unpaddedbase64 import decode_base64
 
 from twisted.internet import defer
 
-from synapse.api.constants import EventTypes, Membership, RejectedReason
+from synapse.api.constants import (
+    KNOWN_ROOM_VERSIONS,
+    EventTypes,
+    Membership,
+    RejectedReason,
+)
 from synapse.api.errors import (
     AuthError,
     CodeMessageException,
@@ -922,6 +927,9 @@ class FederationHandler(BaseHandler):
             joinee,
             "join",
             content,
+            params={
+                "ver": KNOWN_ROOM_VERSIONS,
+            },
         )
 
         # This shouldn't happen, because the RoomMemberHandler has a
@@ -1187,13 +1195,14 @@ class FederationHandler(BaseHandler):
 
     @defer.inlineCallbacks
     def _make_and_verify_event(self, target_hosts, room_id, user_id, membership,
-                               content={},):
+                               content={}, params=None):
         origin, pdu = yield self.federation_client.make_membership_event(
             target_hosts,
             room_id,
             user_id,
             membership,
             content,
+            params=params,
         )
 
         logger.debug("Got response to make_%s: %s", membership, pdu)
diff --git a/synapse/handlers/room.py b/synapse/handlers/room.py
index 7b7804d9b2..6a17c42238 100644
--- a/synapse/handlers/room.py
+++ b/synapse/handlers/room.py
@@ -21,9 +21,17 @@ import math
 import string
 from collections import OrderedDict
 
+from six import string_types
+
 from twisted.internet import defer
 
-from synapse.api.constants import EventTypes, JoinRules, RoomCreationPreset
+from synapse.api.constants import (
+    DEFAULT_ROOM_VERSION,
+    KNOWN_ROOM_VERSIONS,
+    EventTypes,
+    JoinRules,
+    RoomCreationPreset,
+)
 from synapse.api.errors import AuthError, Codes, StoreError, SynapseError
 from synapse.types import RoomAlias, RoomID, RoomStreamToken, StreamToken, UserID
 from synapse.util import stringutils
@@ -99,6 +107,21 @@ class RoomCreationHandler(BaseHandler):
         if ratelimit:
             yield self.ratelimit(requester)
 
+        room_version = config.get("room_version", DEFAULT_ROOM_VERSION)
+        if not isinstance(room_version, string_types):
+            raise SynapseError(
+                400,
+                "room_version must be a string",
+                Codes.BAD_JSON,
+            )
+
+        if room_version not in KNOWN_ROOM_VERSIONS:
+            raise SynapseError(
+                400,
+                "Your homeserver does not support this room version",
+                Codes.UNSUPPORTED_ROOM_VERSION,
+            )
+
         if "room_alias_name" in config:
             for wchar in string.whitespace:
                 if wchar in config["room_alias_name"]:
@@ -184,6 +207,9 @@ class RoomCreationHandler(BaseHandler):
 
         creation_content = config.get("creation_content", {})
 
+        # override any attempt to set room versions via the creation_content
+        creation_content["room_version"] = room_version
+
         room_member_handler = self.hs.get_room_member_handler()
 
         yield self._send_events_for_new_room(