Allow Configurable Rate Limiting Per AS

synapse/api/auth.py

@@ -603,10 +603,12 @@ def get_user_by_req(self, request, allow_guest=False, rights="access"):
         """
         # Can optionally look elsewhere in the request (e.g. headers)
         try:
-            user_id = yield self._get_appservice_user_id(request)
+            user_id, app_service = yield self._get_appservice_user_id(request)
             if user_id:
                 request.authenticated_entity = user_id
-                defer.returnValue(synapse.types.create_requester(user_id))
+                defer.returnValue(
+                    synapse.types.create_requester(user_id, app_service=app_service)
+                )
 
             access_token = get_access_token_from_request(
                 request, self.TOKEN_NOT_FOUND_HTTP_STATUS
@@ -644,7 +646,8 @@ def get_user_by_req(self, request, allow_guest=False, rights="access"):
             request.authenticated_entity = user.to_string()
 
             defer.returnValue(synapse.types.create_requester(
-                user, token_id, is_guest, device_id))
+                user, token_id, is_guest, device_id, app_service=app_service)
+            )
         except KeyError:
             raise AuthError(
                 self.TOKEN_NOT_FOUND_HTTP_STATUS, "Missing access token.",
@@ -659,14 +662,14 @@ def _get_appservice_user_id(self, request):
             )
         )
         if app_service is None:
-            defer.returnValue(None)
+            defer.returnValue((None, None))
 
         if "user_id" not in request.args:
-            defer.returnValue(app_service.sender)
+            defer.returnValue((app_service.sender, app_service))
 
         user_id = request.args["user_id"][0]
         if app_service.sender == user_id:
-            defer.returnValue(app_service.sender)
+            defer.returnValue((app_service.sender, app_service))
 
         if not app_service.is_interested_in_user(user_id):
             raise AuthError(
@@ -678,7 +681,7 @@ def _get_appservice_user_id(self, request):
                 403,
                 "Application service has not registered this user"
             )
-        defer.returnValue(user_id)
+        defer.returnValue((user_id, app_service))
 
     @defer.inlineCallbacks
     def get_user_by_access_token(self, token, rights="access"):

synapse/appservice/__init__.py

@@ -81,7 +81,7 @@ class ApplicationService(object):
     NS_LIST = [NS_USERS, NS_ALIASES, NS_ROOMS]
 
     def __init__(self, token, url=None, namespaces=None, hs_token=None,
-                 sender=None, id=None, protocols=None):
+                 sender=None, id=None, protocols=None, rate_limited=True):
         self.token = token
         self.url = url
         self.hs_token = hs_token
@@ -95,6 +95,8 @@ def __init__(self, token, url=None, namespaces=None, hs_token=None,
         else:
             self.protocols = set()
 
+        self.rate_limited = rate_limited
+
     def _check_namespaces(self, namespaces):
         # Sanity check that it is of the form:
         # {
@@ -234,5 +236,8 @@ def is_exclusive_alias(self, alias):
     def is_exclusive_room(self, room_id):
         return self._is_exclusive(ApplicationService.NS_ROOMS, room_id)
 
+    def is_rate_limited(self):
+        return self.rate_limited
+
     def __str__(self):
         return "ApplicationService: %s" % (self.__dict__,)

synapse/config/appservice.py

@@ -110,6 +110,11 @@ def _load_appservice(hostname, as_info, config_filename):
     user = UserID(localpart, hostname)
     user_id = user.to_string()
 
+    # Rate limiting for users of this AS is on by default (excludes sender)
+    rate_limited = True
+    if isinstance(as_info.get("rate_limited"), bool):
+        rate_limited = as_info.get("rate_limited")
+
     # namespace checks
     if not isinstance(as_info.get("namespaces"), dict):
         raise KeyError("Requires 'namespaces' object.")
@@ -155,4 +160,5 @@ def _load_appservice(hostname, as_info, config_filename):
         sender=user_id,
         id=as_info["id"],
         protocols=protocols,
+        rate_limited=rate_limited
     )

synapse/handlers/_base.py

@@ -57,10 +57,16 @@ def ratelimit(self, requester):
         time_now = self.clock.time()
         user_id = requester.user.to_string()
 
+        # The AS user itself is never rate limited.
         app_service = self.store.get_app_service_by_user_id(user_id)
         if app_service is not None:
             return  # do not ratelimit app service senders
 
+        # Disable rate limiting of users belonging to any AS that is configured
+        # not to be rate limited in its registration file (rate_limited: true|false).
+        if requester.app_service and not requester.app_service.is_rate_limited():
+            return
+
         allowed, time_allowed = self.ratelimiter.send_message(
             user_id, time_now,
             msg_rate_hz=self.hs.config.rc_messages_per_second,

synapse/types.py

@@ -19,7 +19,7 @@
 
 
 Requester = namedtuple("Requester",
-                       ["user", "access_token_id", "is_guest", "device_id"])
+                       ["user", "access_token_id", "is_guest", "device_id", "app_service"])
 """
 Represents the user making a request
 
@@ -29,11 +29,12 @@
         request, or None if it came via the appservice API or similar
     is_guest (bool):  True if the user making this request is a guest user
     device_id (str|None):  device_id which was set at authentication time
+    app_service (ApplicationService|None):  the AS requesting on behalf of the user
 """
 
 
 def create_requester(user_id, access_token_id=None, is_guest=False,
-                     device_id=None):
+                     device_id=None, app_service=None):
     """
     Create a new ``Requester`` object
 
@@ -43,13 +44,14 @@ def create_requester(user_id, access_token_id=None, is_guest=False,
             request, or None if it came via the appservice API or similar
         is_guest (bool):  True if the user making this request is a guest user
         device_id (str|None):  device_id which was set at authentication time
+        app_service (ApplicationService|None):  the AS requesting on behalf of the user
 
     Returns:
         Requester
     """
     if not isinstance(user_id, UserID):
         user_id = UserID.from_string(user_id)
-    return Requester(user_id, access_token_id, is_guest, device_id)
+    return Requester(user_id, access_token_id, is_guest, device_id, app_service)
 
 
 def get_domain_from_id(string):