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
# limitations under the License.
#
"""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 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]