1 files changed, 111 insertions, 0 deletions
diff --git a/diplomacy/server/connection_handler.py b/diplomacy/server/connection_handler.py
new file mode 100644
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+++ b/diplomacy/server/connection_handler.py
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+# ==============================================================================
+# Copyright (C) 2019 - Philip Paquette, Steven Bocco
+#
+#  This program is free software: you can redistribute it and/or modify it under
+#  the terms of the GNU Affero General Public License as published by the Free
+#  Software Foundation, either version 3 of the License, or (at your option) any
+#  later version.
+#
+#  This program is distributed in the hope that it will be useful, but WITHOUT
+#  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+#  FOR A PARTICULAR PURPOSE.  See the GNU Affero General Public License for more
+#  details.
+#
+#  You should have received a copy of the GNU Affero General Public License along
+#  with this program.  If not, see <https://www.gnu.org/licenses/>.
+# ==============================================================================
+""" Tornado connection handler class, used internally to manage data received by server application. """
+import logging
+
+from urllib.parse import urlparse
+from tornado import gen
+from tornado.websocket import WebSocketHandler, WebSocketClosedError
+
+import ujson as json
+
+from diplomacy.communication import responses, requests
+from diplomacy.server import request_managers
+from diplomacy.utils import exceptions, strings
+
+
+LOGGER = logging.getLogger(__name__)
+
+class ConnectionHandler(WebSocketHandler):
+    """ ConnectionHandler class. Properties:
+        - server: server object representing running server.
+    """
+    # pylint: disable=abstract-method
+
+    def __init__(self, *args, **kwargs):
+        self.server = None
+        super(ConnectionHandler, self).__init__(*args, **kwargs)
+
+    def initialize(self, server=None):
+        """ Initialize the connection handler.
+            :param server: a Server object.
+            :type server: diplomacy.Server
+        """
+        # pylint: disable=arguments-differ
+        if self.server is None:
+            self.server = server
+
+    def get_compression_options(self):
+        """ Return compression options for the connection (see parent method).
+            Non-None enables compression with default options.
+        """
+        return {}
+
+    def check_origin(self, origin):
+        """ Return True if we should accept connexion from given origin (str). """
+
+        # It seems origin may be 'null', e.g. if client is a web page loaded from disk (`file:///my_test_file.html`).
+        # Accept it.
+        if origin == 'null':
+            return True
+
+        # Try to check if origin matches host (without regarding port).
+        # Adapted from parent method code (tornado 4.5.3).
+        parsed_origin = urlparse(origin)
+        origin = parsed_origin.netloc.split(':')[0]
+        origin = origin.lower()
+        # Split host with ':' and keep only first piece to ignore eventual port.
+        host = self.request.headers.get("Host").split(':')[0]
+        return origin == host
+
+    def on_close(self):
+        """ Invoked when the socket is closed (see parent method).
+            Detach this connection handler from server users.
+        """
+        self.server.users.remove_connection(self, remove_tokens=False)
+        LOGGER.info("Removed connection. Remaining %d connection(s).", self.server.users.count_connections())
+
+    @gen.coroutine
+    def on_message(self, message):
+        """ Parse given message and manage parsed data (expected a string representation of a request). """
+        try:
+            json_request = json.loads(message)
+            if not isinstance(json_request, dict):
+                raise ValueError("Unable to convert a JSON string to a dictionary.")
+        except ValueError as exc:
+            # Error occurred because either message is not a JSON string or parsed JSON object is not a dict.
+            response = responses.Error(message='%s/%s' % (type(exc).__name__, str(exc)))
+        else:
+            try:
+                request = requests.parse_dict(json_request)
+
+                if request.level is not None:
+                    # Link request token to this connection handler.
+                    self.server.users.attach_connection_handler(request.token, self)
+
+                response = yield request_managers.handle_request(self.server, request, self)
+                if response is None:
+                    response = responses.Ok(request_id=request.request_id)
+
+            except exceptions.ResponseException as exc:
+                response = responses.Error(message='%s/%s' % (type(exc).__name__, exc.message),
+                                           request_id=json_request.get(strings.REQUEST_ID, None))
+
+        try:
+            yield self.write_message(response.json())
+        except WebSocketClosedError:
+            LOGGER.error('Websocket is closed.')