From 5b54d51d1e98450451b8ffe3a57ad98373e8f5e6 Mon Sep 17 00:00:00 2001
From: Luke Barnard <lukeb@openmarket.com>
Date: Tue, 18 Oct 2016 17:04:09 +0100
Subject: [PATCH] Allow Configurable Rate Limiting Per AS

This adds a flag loaded from the registration file of an AS that will determine whether or not its users are rate limited (by ratelimit in _base.py). Needed for IRC bridge reasons - see https://github.com/matrix-org/matrix-appservice-irc/issues/240.
---
 synapse/appservice/__init__.py |  7 ++++++-
 synapse/config/appservice.py   |  6 ++++++
 synapse/handlers/_base.py      | 14 ++++++++++++++
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/synapse/appservice/__init__.py b/synapse/appservice/__init__.py
index 126a10efb7..91471f7e89 100644
--- a/synapse/appservice/__init__.py
+++ b/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 @@ class ApplicationService(object):
         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 @@ class ApplicationService(object):
     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__,)
diff --git a/synapse/config/appservice.py b/synapse/config/appservice.py
index d7537e8d44..82c50b8240 100644
--- a/synapse/config/appservice.py
+++ b/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
     )
diff --git a/synapse/handlers/_base.py b/synapse/handlers/_base.py
index 4981643166..a377b1225b 100644
--- a/synapse/handlers/_base.py
+++ b/synapse/handlers/_base.py
@@ -57,10 +57,24 @@ class BaseHandler(object):
         time_now = self.clock.time()
         user_id = requester.user.to_string()
 
+        # 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).
+        # 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
 
+        should_rate_limit = True
+
+        for service in self.store.get_app_services():
+            if service.is_interested_in_user(user_id):
+                should_rate_limit = service.is_rate_limited()
+                break
+
+        if not should_rate_limit:
+            return
+
         allowed, time_allowed = self.ratelimiter.send_message(
             user_id, time_now,
             msg_rate_hz=self.hs.config.rc_messages_per_second,