Source code for google.appengine.api.dosinfo

#!/usr/bin/env python
#
# Copyright 2007 Google Inc.
#
# 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
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"""DOS configuration tools.

Library for parsing dos.yaml files and working with these in memory.
"""

from __future__ import absolute_import
from __future__ import unicode_literals







import os
import re
import google
from google.appengine._internal import six_subset



if six_subset.PY2:
  import ipaddr
else:
  ipaddr = None


if os.environ.get('APPENGINE_RUNTIME') == 'python27':
  from google.appengine.api import appinfo
  from google.appengine.api import validation
  from google.appengine.api import yaml_builder
  from google.appengine.api import yaml_listener
  from google.appengine.api import yaml_object
else:
  from google.appengine.api import appinfo
  from google.appengine.api import validation
  from google.appengine.api import yaml_builder
  from google.appengine.api import yaml_listener
  from google.appengine.api import yaml_object


_DESCRIPTION_REGEX = r'^.{0,499}$'

BLACKLIST = 'blacklist'
DESCRIPTION = 'description'
SUBNET = 'subnet'


[docs]class SubnetValidator(validation.Validator): """Checks that a subnet can be parsed and is a valid IPv4 or IPv6 subnet."""
[docs] def Validate(self, value, unused_key=None): """Validates a subnet.""" if value is None: raise validation.MissingAttribute('subnet must be specified') if not isinstance(value, six_subset.string_types): raise validation.ValidationError('subnet must be a string, not \'%r\'' % type(value)) if ipaddr: try: ipaddr.IPNetwork(value) except ValueError: raise validation.ValidationError( '%s is not a valid IPv4 or IPv6 subnet' % value) parts = value.split('/') if len(parts) == 2 and not re.match('^[0-9]+$', parts[1]): raise validation.ValidationError('Prefix length of subnet %s must be an ' 'integer (quad-dotted masks are not ' 'supported)' % value) return value
[docs]class MalformedDosConfiguration(Exception): """Configuration file for DOS API is malformed."""
[docs]class BlacklistEntry(validation.Validated): """A blacklist entry describes a blocked IP address or subnet.""" ATTRIBUTES = { DESCRIPTION: validation.Optional(_DESCRIPTION_REGEX), SUBNET: SubnetValidator(), }
[docs]class DosInfoExternal(validation.Validated): """Describes the format of a dos.yaml file.""" ATTRIBUTES = { appinfo.APPLICATION: validation.Optional(appinfo.APPLICATION_RE_STRING), BLACKLIST: validation.Optional(validation.Repeated(BlacklistEntry)), }
[docs]def LoadSingleDos(dos_info, open_fn=None): """Load a dos.yaml file or string and return a DosInfoExternal object. Args: dos_info: The contents of a dos.yaml file as a string, or an open file object. open_fn: Function for opening files. Unused. Returns: A DosInfoExternal instance which represents the contents of the parsed yaml file. Raises: MalformedDosConfiguration: The yaml file contains multiple blacklist sections. yaml_errors.EventError: An error occured while parsing the yaml file. """ builder = yaml_object.ObjectBuilder(DosInfoExternal) handler = yaml_builder.BuilderHandler(builder) listener = yaml_listener.EventListener(handler) listener.Parse(dos_info) parsed_yaml = handler.GetResults() if not parsed_yaml: return DosInfoExternal() if len(parsed_yaml) > 1: raise MalformedDosConfiguration('Multiple blacklist: sections ' 'in configuration.') return parsed_yaml[0]