Merge pull request #101 from matrix-org/neaten-federation-servlets

Neaten federation servlets

1 files changed, 157 insertions, 182 deletions

diff --git a/synapse/federation/transport/server.py b/synapse/federation/transport/server.py
index ece6dbcf62..6c624977d7 100644
--- a/synapse/federation/transport/server.py
+++ b/synapse/federation/transport/server.py
@@ -19,6 +19,7 @@ from synapse.api.urls import FEDERATION_PREFIX as PREFIX
 from synapse.api.errors import Codes, SynapseError
 from synapse.util.logutils import log_function
 
+import functools
 import logging
 import simplejson as json
 import re
@@ -30,8 +31,9 @@ logger = logging.getLogger(__name__)
 class TransportLayerServer(object):
     """Handles incoming federation HTTP requests"""
 
+    # A method just so we can pass 'self' as the authenticator to the Servlets
     @defer.inlineCallbacks
-    def _authenticate_request(self, request):
+    def authenticate_request(self, request):
         json_request = {
             "method": request.method,
             "uri": request.uri,
@@ -93,28 +95,6 @@ class TransportLayerServer(object):
 
         defer.returnValue((origin, content))
 
-    def _with_authentication(self, handler):
-        @defer.inlineCallbacks
-        def new_handler(request, *args, **kwargs):
-            try:
-                (origin, content) = yield self._authenticate_request(request)
-                with self.ratelimiter.ratelimit(origin) as d:
-                    yield d
-                    response = yield handler(
-                        origin, content, request.args, *args, **kwargs
-                    )
-            except:
-                logger.exception("_authenticate_request failed")
-                raise
-            defer.returnValue(response)
-        return new_handler
-
-    def rate_limit_origin(self, handler):
-        def new_handler(origin, *args, **kwargs):
-            response = yield handler(origin, *args, **kwargs)
-            defer.returnValue(response)
-        return new_handler()
-
     @log_function
     def register_received_handler(self, handler):
         """ Register a handler that will be fired when we receive data.
@@ -122,14 +102,12 @@ class TransportLayerServer(object):
         Args:
             handler (TransportReceivedHandler)
         """
-        self.received_handler = handler
-
-        # This is when someone is trying to send us a bunch of data.
-        self.server.register_path(
-            "PUT",
-            re.compile("^" + PREFIX + "/send/([^/]*)/$"),
-            self._with_authentication(self._on_send_request)
-        )
+        FederationSendServlet(
+            handler,
+            authenticator=self,
+            ratelimiter=self.ratelimiter,
+            server_name=self.server_name,
+        ).register(self.server)
 
     @log_function
     def register_request_handler(self, handler):
@@ -138,136 +116,61 @@ class TransportLayerServer(object):
         Args:
             handler (TransportRequestHandler)
         """
-        self.request_handler = handler
-
-        # This is for when someone asks us for everything since version X
-        self.server.register_path(
-            "GET",
-            re.compile("^" + PREFIX + "/pull/$"),
-            self._with_authentication(
-                lambda origin, content, query:
-                handler.on_pull_request(query["origin"][0], query["v"])
-            )
-        )
+        for servletclass in SERVLET_CLASSES:
+            servletclass(
+                handler,
+                authenticator=self,
+                ratelimiter=self.ratelimiter,
+            ).register(self.server)
 
-        # This is when someone asks for a data item for a given server
-        # data_id pair.
-        self.server.register_path(
-            "GET",
-            re.compile("^" + PREFIX + "/event/([^/]*)/$"),
-            self._with_authentication(
-                lambda origin, content, query, event_id:
-                handler.on_pdu_request(origin, event_id)
-            )
-        )
 
-        # This is when someone asks for all data for a given context.
-        self.server.register_path(
-            "GET",
-            re.compile("^" + PREFIX + "/state/([^/]*)/$"),
-            self._with_authentication(
-                lambda origin, content, query, context:
-                handler.on_context_state_request(
-                    origin,
-                    context,
-                    query.get("event_id", [None])[0],
-                )
-            )
-        )
+class BaseFederationServlet(object):
+    def __init__(self, handler, authenticator, ratelimiter):
+        self.handler = handler
+        self.authenticator = authenticator
+        self.ratelimiter = ratelimiter
 
-        self.server.register_path(
-            "GET",
-            re.compile("^" + PREFIX + "/backfill/([^/]*)/$"),
-            self._with_authentication(
-                lambda origin, content, query, context:
-                self._on_backfill_request(
-                    origin, context, query["v"], query["limit"]
-                )
-            )
-        )
+    def _wrap(self, code):
+        authenticator = self.authenticator
+        ratelimiter = self.ratelimiter
 
-        # This is when we receive a server-server Query
-        self.server.register_path(
-            "GET",
-            re.compile("^" + PREFIX + "/query/([^/]*)$"),
-            self._with_authentication(
-                lambda origin, content, query, query_type:
-                handler.on_query_request(
-                    query_type,
-                    {k: v[0].decode("utf-8") for k, v in query.items()}
-                )
-            )
-        )
+        @defer.inlineCallbacks
+        @functools.wraps(code)
+        def new_code(request, *args, **kwargs):
+            try:
+                (origin, content) = yield authenticator.authenticate_request(request)
+                with ratelimiter.ratelimit(origin) as d:
+                    yield d
+                    response = yield code(
+                        origin, content, request.args, *args, **kwargs
+                    )
+            except:
+                logger.exception("authenticate_request failed")
+                raise
+            defer.returnValue(response)
+        return new_code
 
-        self.server.register_path(
-            "GET",
-            re.compile("^" + PREFIX + "/make_join/([^/]*)/([^/]*)$"),
-            self._with_authentication(
-                lambda origin, content, query, context, user_id:
-                self._on_make_join_request(
-                    origin, content, query, context, user_id
-                )
-            )
-        )
+    def register(self, server):
+        pattern = re.compile("^" + PREFIX + self.PATH + "$")
 
-        self.server.register_path(
-            "GET",
-            re.compile("^" + PREFIX + "/event_auth/([^/]*)/([^/]*)$"),
-            self._with_authentication(
-                lambda origin, content, query, context, event_id:
-                handler.on_event_auth(
-                    origin, context, event_id,
-                )
-            )
-        )
+        for method in ("GET", "PUT", "POST"):
+            code = getattr(self, "on_%s" % (method), None)
+            if code is None:
+                continue
 
-        self.server.register_path(
-            "PUT",
-            re.compile("^" + PREFIX + "/send_join/([^/]*)/([^/]*)$"),
-            self._with_authentication(
-                lambda origin, content, query, context, event_id:
-                self._on_send_join_request(
-                    origin, content, query,
-                )
-            )
-        )
+            server.register_path(method, pattern, self._wrap(code))
 
-        self.server.register_path(
-            "PUT",
-            re.compile("^" + PREFIX + "/invite/([^/]*)/([^/]*)$"),
-            self._with_authentication(
-                lambda origin, content, query, context, event_id:
-                self._on_invite_request(
-                    origin, content, query,
-                )
-            )
-        )
 
-        self.server.register_path(
-            "POST",
-            re.compile("^" + PREFIX + "/query_auth/([^/]*)/([^/]*)$"),
-            self._with_authentication(
-                lambda origin, content, query, context, event_id:
-                self._on_query_auth_request(
-                    origin, content, event_id,
-                )
-            )
-        )
+class FederationSendServlet(BaseFederationServlet):
+    PATH = "/send/([^/]*)/"
 
-        self.server.register_path(
-            "POST",
-            re.compile("^" + PREFIX + "/get_missing_events/([^/]*)/?$"),
-            self._with_authentication(
-                lambda origin, content, query, room_id:
-                self._get_missing_events(
-                    origin, content, room_id,
-                )
-            )
-        )
+    def __init__(self, handler, server_name, **kwargs):
+        super(FederationSendServlet, self).__init__(handler, **kwargs)
+        self.server_name = server_name
 
+    # This is when someone is trying to send us a bunch of data.
     @defer.inlineCallbacks
-    @log_function
-    def _on_send_request(self, origin, content, query, transaction_id):
+    def on_PUT(self, origin, content, query, transaction_id):
         """ Called on PUT /send/<transaction_id>/
 
         Args:
@@ -305,8 +208,7 @@ class TransportLayerServer(object):
             return
 
         try:
-            handler = self.received_handler
-            code, response = yield handler.on_incoming_transaction(
+            code, response = yield self.handler.on_incoming_transaction(
                 transaction_data
             )
         except:
@@ -315,65 +217,123 @@ class TransportLayerServer(object):
 
         defer.returnValue((code, response))
 
-    @log_function
-    def _on_backfill_request(self, origin, context, v_list, limits):
+
+class FederationPullServlet(BaseFederationServlet):
+    PATH = "/pull/"
+
+    # This is for when someone asks us for everything since version X
+    def on_GET(self, origin, content, query):
+        return self.handler.on_pull_request(query["origin"][0], query["v"])
+
+
+class FederationEventServlet(BaseFederationServlet):
+    PATH = "/event/([^/]*)/"
+
+    # This is when someone asks for a data item for a given server data_id pair.
+    def on_GET(self, origin, content, query, event_id):
+        return self.handler.on_pdu_request(origin, event_id)
+
+
+class FederationStateServlet(BaseFederationServlet):
+    PATH = "/state/([^/]*)/"
+
+    # This is when someone asks for all data for a given context.
+    def on_GET(self, origin, content, query, context):
+        return self.handler.on_context_state_request(
+            origin,
+            context,
+            query.get("event_id", [None])[0],
+        )
+
+
+class FederationBackfillServlet(BaseFederationServlet):
+    PATH = "/backfill/([^/]*)/"
+
+    def on_GET(self, origin, content, query, context):
+        versions = query["v"]
+        limits = query["limit"]
+
         if not limits:
-            return defer.succeed(
-                (400, {"error": "Did not include limit param"})
-            )
+            return defer.succeed((400, {"error": "Did not include limit param"}))
 
         limit = int(limits[-1])
 
-        versions = v_list
+        return self.handler.on_backfill_request(origin, context, versions, limit)
 
-        return self.request_handler.on_backfill_request(
-            origin, context, versions, limit
+
+class FederationQueryServlet(BaseFederationServlet):
+    PATH = "/query/([^/]*)"
+
+    # This is when we receive a server-server Query
+    def on_GET(self, origin, content, query, query_type):
+        return self.handler.on_query_request(
+            query_type,
+            {k: v[0].decode("utf-8") for k, v in query.items()}
         )
 
+
+class FederationMakeJoinServlet(BaseFederationServlet):
+    PATH = "/make_join/([^/]*)/([^/]*)"
+
     @defer.inlineCallbacks
-    @log_function
-    def _on_make_join_request(self, origin, content, query, context, user_id):
-        content = yield self.request_handler.on_make_join_request(
-            context, user_id,
-        )
+    def on_GET(self, origin, content, query, context, user_id):
+        content = yield self.handler.on_make_join_request(context, user_id)
         defer.returnValue((200, content))
 
-    @defer.inlineCallbacks
-    @log_function
-    def _on_send_join_request(self, origin, content, query):
-        content = yield self.request_handler.on_send_join_request(
-            origin, content,
-        )
 
-        defer.returnValue((200, content))
+class FederationEventAuthServlet(BaseFederationServlet):
+    PATH = "/event_auth/([^/]*)/([^/]*)"
+
+    def on_GET(self, origin, content, query, context, event_id):
+        return self.handler.on_event_auth(origin, context, event_id)
+
+
+class FederationSendJoinServlet(BaseFederationServlet):
+    PATH = "/send_join/([^/]*)/([^/]*)"
 
     @defer.inlineCallbacks
-    @log_function
-    def _on_invite_request(self, origin, content, query):
-        content = yield self.request_handler.on_invite_request(
-            origin, content,
-        )
+    def on_PUT(self, origin, content, query, context, event_id):
+        # TODO(paul): assert that context/event_id parsed from path actually
+        #   match those given in content
+        content = yield self.handler.on_send_join_request(origin, content)
+        defer.returnValue((200, content))
+
+
+class FederationInviteServlet(BaseFederationServlet):
+    PATH = "/invite/([^/]*)/([^/]*)"
 
+    @defer.inlineCallbacks
+    def on_PUT(self, origin, content, query, context, event_id):
+        # TODO(paul): assert that context/event_id parsed from path actually
+        #   match those given in content
+        content = yield self.handler.on_invite_request(origin, content)
         defer.returnValue((200, content))
 
+
+class FederationQueryAuthServlet(BaseFederationServlet):
+    PATH = "/query_auth/([^/]*)/([^/]*)"
+
     @defer.inlineCallbacks
-    @log_function
-    def _on_query_auth_request(self, origin, content, event_id):
-        new_content = yield self.request_handler.on_query_auth_request(
+    def on_POST(self, origin, content, query, context, event_id):
+        new_content = yield self.handler.on_query_auth_request(
             origin, content, event_id
         )
 
         defer.returnValue((200, new_content))
 
+
+class FederationGetMissingEventsServlet(BaseFederationServlet):
+    # TODO(paul): Why does this path alone end with "/?" optional?
+    PATH = "/get_missing_events/([^/]*)/?"
+
     @defer.inlineCallbacks
-    @log_function
-    def _get_missing_events(self, origin, content, room_id):
+    def on_POST(self, origin, content, query, room_id):
         limit = int(content.get("limit", 10))
         min_depth = int(content.get("min_depth", 0))
         earliest_events = content.get("earliest_events", [])
         latest_events = content.get("latest_events", [])
 
-        content = yield self.request_handler.on_get_missing_events(
+        content = yield self.handler.on_get_missing_events(
             origin,
             room_id=room_id,
             earliest_events=earliest_events,
@@ -383,3 +343,18 @@ class TransportLayerServer(object):
         )
 
         defer.returnValue((200, content))
+
+
+SERVLET_CLASSES = (
+    FederationPullServlet,
+    FederationEventServlet,
+    FederationStateServlet,
+    FederationBackfillServlet,
+    FederationQueryServlet,
+    FederationMakeJoinServlet,
+    FederationEventServlet,
+    FederationSendJoinServlet,
+    FederationInviteServlet,
+    FederationQueryAuthServlet,
+    FederationGetMissingEventsServlet,
+)