3 files changed, 20 insertions, 0 deletions
diff --git a/synapse/rest/client/v2_alpha/_base.py b/synapse/rest/client/v2_alpha/_base.py
index 20e765f48f..1f5bc24cc3 100644
--- a/synapse/rest/client/v2_alpha/_base.py
+++ b/synapse/rest/client/v2_alpha/_base.py
@@ -47,3 +47,13 @@ def client_v2_patterns(path_regex, releases=(0,),
         new_prefix = CLIENT_V2_ALPHA_PREFIX.replace("/v2_alpha", "/r%d" % release)
         patterns.append(re.compile("^" + new_prefix + path_regex))
     return patterns
+
+
+def set_timeline_upper_limit(filter_json, filter_timeline_limit):
+    if filter_timeline_limit < 0:
+        return  # no upper limits
+    timeline = filter_json.get('room', {}).get('timeline', {})
+    if 'limit' in timeline:
+        filter_json['room']['timeline']["limit"] = min(
+            filter_json['room']['timeline']['limit'],
+            filter_timeline_limit)
diff --git a/synapse/rest/client/v2_alpha/filter.py b/synapse/rest/client/v2_alpha/filter.py
index b4084fec62..d2b2fd66e6 100644
--- a/synapse/rest/client/v2_alpha/filter.py
+++ b/synapse/rest/client/v2_alpha/filter.py
@@ -20,6 +20,7 @@ from synapse.http.servlet import RestServlet, parse_json_object_from_request
 from synapse.types import UserID
 
 from ._base import client_v2_patterns
+from ._base import set_timeline_upper_limit
 
 import logging
 
@@ -85,6 +86,11 @@ class CreateFilterRestServlet(RestServlet):
             raise AuthError(403, "Can only create filters for local users")
 
         content = parse_json_object_from_request(request)
+        set_timeline_upper_limit(
+            content,
+            self.hs.config.filter_timeline_limit
+        )
+
         filter_id = yield self.filtering.add_user_filter(
             user_localpart=target_user.localpart,
             user_filter=content,
diff --git a/synapse/rest/client/v2_alpha/sync.py b/synapse/rest/client/v2_alpha/sync.py
index f30eab76fd..771e127ab9 100644
--- a/synapse/rest/client/v2_alpha/sync.py
+++ b/synapse/rest/client/v2_alpha/sync.py
@@ -28,6 +28,7 @@ from synapse.api.filtering import FilterCollection, DEFAULT_FILTER_COLLECTION
 from synapse.api.errors import SynapseError
 from synapse.api.constants import PresenceState
 from ._base import client_v2_patterns
+from ._base import set_timeline_upper_limit
 
 import itertools
 import logging
@@ -78,6 +79,7 @@ class SyncRestServlet(RestServlet):
 
     def __init__(self, hs):
         super(SyncRestServlet, self).__init__()
+        self.hs = hs
         self.auth = hs.get_auth()
         self.sync_handler = hs.get_sync_handler()
         self.clock = hs.get_clock()
@@ -121,6 +123,8 @@ class SyncRestServlet(RestServlet):
             if filter_id.startswith('{'):
                 try:
                     filter_object = json.loads(filter_id)
+                    set_timeline_upper_limit(filter_object,
+                                             self.hs.config.filter_timeline_limit)
                 except:
                     raise SynapseError(400, "Invalid filter JSON")
                 self.filtering.check_valid_filter(filter_object)