Open Source Monorail

appengine/monorail/framework/banned.py

+# Copyright 2016 The Chromium Authors. All rights reserved.
+# Use of this source code is govered by a BSD-style
+# license that can be found in the LICENSE file or at
+# https://developers.google.com/open-source/licenses/bsd
+
+"""A class to display the a message explaining that the user has been banned.
+
+We can ban a user for anti-social behavior.  We indicate that the user is
+banned by adding a 'banned' field to his/her User PB in the DB.  Whenever
+a user with a banned indicator visits any page, AssertBasePermission()
+checks has_banned and redirects to this page.
+"""
+
+import logging
+
+from framework import permissions
+from framework import servlet
+
+
+class Banned(servlet.Servlet):
+  """The Banned page shows a message explaining that the user is banned."""
+
+  _PAGE_TEMPLATE = 'framework/banned-page.ezt'
+
+  def AssertBasePermission(self, mr):
+    """Allow banned users to see this page, and prevent non-banned users."""
+    # Note, we do not call Servlet.AssertBasePermission because
+    # that would redirect banned users here again in an endless loop.
+
+    # We only show this page to users who are banned.  If a non-banned user
+    # follows a link to this URL, don't show the banned message, because that
+    # would lead to a big misunderstanding.
+    if not permissions.IsBanned(mr.auth.user_pb, mr.auth.user_view):
+      logging.info('non-banned user: %s', mr.auth.user_pb)
+      self.abort(404)
+
+  def GatherPageData(self, _mr):
+    """Build up a dictionary of data values to use when rendering the page."""
+    return {
+        # We do not actually display the specific reason for banning.
+        # That info is available via command-line tools..
+
+        # Make the "Sign Out" link just sign out, don't try to bring the
+        # user back to this page after they sign out.
+        'currentPageURLEncoded': None,
+        }