Adds middleware to limit request body sizes.

Fixes LP Bug #962515.

Change-Id: Ic1be1459515654d45febd89da58b19e0840aaf9d

2 files changed, 105 insertions, 0 deletions

diff --git a/nova/api/sizelimit.py b/nova/api/sizelimit.py
new file mode 100644
index 000000000..69eee19bb
--- /dev/null
+++ b/nova/api/sizelimit.py
@@ -0,0 +1,54 @@
+# vim: tabstop=4 shiftwidth=4 softtabstop=4
+
+# Copyright (c) 2012 OpenStack, LLC
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+"""
+Request Body limiting middleware.
+
+"""
+
+import webob.dec
+import webob.exc
+
+from nova import context
+from nova import flags
+from nova import log as logging
+from nova.openstack.common import cfg
+from nova import wsgi
+
+
+#default request size is 112k
+max_request_body_size_opt = cfg.BoolOpt('osapi_max_request_body_size',
+        default=114688,
+        help='')
+
+FLAGS = flags.FLAGS
+FLAGS.register_opt(max_request_body_size_opt)
+LOG = logging.getLogger(__name__)
+
+
+class RequestBodySizeLimiter(wsgi.Middleware):
+    """Add a 'nova.context' to WSGI environ."""
+
+    def __init__(self, *args, **kwargs):
+        super(RequestBodySizeLimiter, self).__init__(*args, **kwargs)
+
+    @webob.dec.wsgify(RequestClass=wsgi.Request)
+    def __call__(self, req):
+        if (req.content_length > FLAGS.osapi_max_request_body_size
+            or len(req.body) > FLAGS.osapi_max_request_body_size):
+            msg = _("Request is too large.")
+            raise webob.exc.HTTPBadRequest(explanation=msg)
+        else:
+            return self.application
diff --git a/nova/tests/api/test_sizelimit.py b/nova/tests/api/test_sizelimit.py
new file mode 100644
index 000000000..170198b6b
--- /dev/null
+++ b/nova/tests/api/test_sizelimit.py
@@ -0,0 +1,51 @@
+# Copyright (c) 2012 OpenStack, LLC
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+import webob
+
+import nova.api.sizelimit
+from nova import flags
+from nova import test
+
+FLAGS = flags.FLAGS
+MAX_REQUEST_BODY_SIZE = FLAGS.osapi_max_request_body_size
+
+
+class TestRequestBodySizeLimiter(test.TestCase):
+
+    def setUp(self):
+        super(TestRequestBodySizeLimiter, self).setUp()
+
+        @webob.dec.wsgify()
+        def fake_app(req):
+            return webob.Response()
+
+        self.middleware = nova.api.sizelimit.RequestBodySizeLimiter(fake_app)
+        self.request = webob.Request.blank('/', method='POST')
+
+    def test_content_length_acceptable(self):
+        self.request.headers['Content-Length'] = MAX_REQUEST_BODY_SIZE
+        self.request.body = "0" * MAX_REQUEST_BODY_SIZE
+        response = self.request.get_response(self.middleware)
+        self.assertEqual(response.status_int, 200)
+
+    def test_content_length_to_large(self):
+        self.request.headers['Content-Length'] = MAX_REQUEST_BODY_SIZE + 1
+        response = self.request.get_response(self.middleware)
+        self.assertEqual(response.status_int, 400)
+
+    def test_request_to_large(self):
+        self.request.body = "0" * (MAX_REQUEST_BODY_SIZE + 1)
+        response = self.request.get_response(self.middleware)
+        self.assertEqual(response.status_int, 400)