incorporate PR feedback

synapse/config/server.py

@@ -55,14 +55,16 @@ class ServerConfig(Config):
             "block_non_admin_invites", False,
         )
 
+        # FIXME: federation_domain_whitelist needs sytests
+        self.federation_domain_whitelist = None
         federation_domain_whitelist = config.get(
-            "federation_domain_whitelist", []
+            "federation_domain_whitelist", None
         )
         # turn the whitelist into a hash for speed of lookup
-        self.federation_domain_whitelist = {}
+        if federation_domain_whitelist is not None:
-        for domain in federation_domain_whitelist:
+            self.federation_domain_whitelist = {}
-            self.federation_domain_whitelist[domain] = True
+            for domain in federation_domain_whitelist:
-        # FIXME: federation_domain_whitelist needs sytests
+                self.federation_domain_whitelist[domain] = True
 
         if self.public_baseurl is not None:
             if self.public_baseurl[-1] != '/':
@@ -222,7 +224,8 @@ class ServerConfig(Config):
         # Restrict federation to the following whitelist of domains.
         # N.B. we recommend also firewalling your federation listener to limit
         # inbound federation traffic as early as possible, rather than relying
-        # purely on this application-layer restriction.
+        # purely on this application-layer restriction.  If not specified, the
+        # default is to whitelist nothing.
         #
         # federation_domain_whitelist:
         #  - lon.example.com

synapse/federation/federation_client.py

@@ -267,7 +267,7 @@ class FederationClient(FederationBase):
                 logger.info(e.message)
                 continue
             except FederationDeniedError as e:
-                logger.debug(e.message)
+                logger.info(e.message)
                 continue
             except Exception as e:
                 pdu_attempts[destination] = now

synapse/federation/transaction_queue.py

@@ -491,7 +491,7 @@ class TransactionQueue(object):
                 ),
             )
         except FederationDeniedError as e:
-            logger.debug(e)
+            logger.info(e)
         except Exception as e:
             logger.warn(
                 "TX [%s] Failed to send transaction: %s",

synapse/federation/transport/server.py

@@ -94,7 +94,7 @@ class Authenticator(object):
         }
 
         if (
-            self.federation_domain_whitelist and
+            self.federation_domain_whitelist is not None and
             self.server_name not in self.federation_domain_whitelist
         ):
             raise FederationDeniedError(self.server_name)

synapse/handlers/device.py

@@ -515,7 +515,7 @@ class DeviceListEduUpdater(object):
                     # eventually become consistent.
                     return
                 except FederationDeniedError as e:
-                    logger.debug(e)
+                    logger.info(e)
                     return
                 except Exception:
                     # TODO: Remember that we are now out of sync and try again

synapse/handlers/federation.py

@@ -784,7 +784,7 @@ class FederationHandler(BaseHandler):
                     logger.info(e.message)
                     continue
                 except FederationDeniedError as e:
-                    logger.debug(e)
+                    logger.info(e)
                     continue
                 except Exception as e:
                     logger.exception(

synapse/rest/key/v2/remote_key_resource.py

@@ -139,7 +139,7 @@ class RemoteKey(Resource):
         store_queries = []
         for server_name, key_ids in query.items():
             if (
-                self.federation_domain_whitelist and
+                self.federation_domain_whitelist is not None and
                 server_name not in self.federation_domain_whitelist
             ):
                 logger.debug("Federation denied with %s", server_name)

synapse/rest/media/v1/media_repository.py

@@ -226,7 +226,7 @@ class MediaRepository(object):
                 to request
         """
         if (
-            self.federation_domain_whitelist and
+            self.federation_domain_whitelist is not None and
             server_name not in self.federation_domain_whitelist
         ):
             raise FederationDeniedError(server_name)
@@ -266,7 +266,7 @@ class MediaRepository(object):
             Deferred[dict]: The media_info of the file
         """
         if (
-            self.federation_domain_whitelist and
+            self.federation_domain_whitelist is not None and
             server_name not in self.federation_domain_whitelist
         ):
             raise FederationDeniedError(server_name)
@@ -387,8 +387,8 @@ class MediaRepository(object):
                 logger.warn("Not retrying destination %r", server_name)
                 raise SynapseError(502, "Failed to fetch remote media")
             except FederationDeniedError as e:
-                logger.debug(e)
+                logger.info(e)
-                raise SynapseError(403, e.message)
+                raise e
             except Exception:
                 logger.exception("Failed to fetch remote media %s/%s",
                                  server_name, media_id)