144 lines
4.7 KiB
Python
144 lines
4.7 KiB
Python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
|
|
|
|
# Copyright (c) 2012 Openstack, LLC.
|
|
# All Rights Reserved.
|
|
#
|
|
# 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 os
|
|
import re
|
|
|
|
|
|
class CommandFilter(object):
|
|
"""Command filter only checking that the 1st argument matches exec_path"""
|
|
|
|
def __init__(self, exec_path, run_as, *args):
|
|
self.exec_path = exec_path
|
|
self.run_as = run_as
|
|
self.args = args
|
|
|
|
def match(self, userargs):
|
|
"""Only check that the first argument (command) matches exec_path"""
|
|
if (os.path.basename(self.exec_path) == userargs[0]):
|
|
return True
|
|
return False
|
|
|
|
def get_command(self, userargs):
|
|
"""Returns command to execute (with sudo -u if run_as != root)."""
|
|
if (self.run_as != 'root'):
|
|
# Used to run commands at lesser privileges
|
|
return ['sudo', '-u', self.run_as, self.exec_path] + userargs[1:]
|
|
return [self.exec_path] + userargs[1:]
|
|
|
|
def get_environment(self, userargs):
|
|
"""Returns specific environment to set, None if none"""
|
|
return None
|
|
|
|
|
|
class RegExpFilter(CommandFilter):
|
|
"""Command filter doing regexp matching for every argument"""
|
|
|
|
def match(self, userargs):
|
|
# Early skip if command or number of args don't match
|
|
if (len(self.args) != len(userargs)):
|
|
# DENY: argument numbers don't match
|
|
return False
|
|
# Compare each arg (anchoring pattern explicitly at end of string)
|
|
for (pattern, arg) in zip(self.args, userargs):
|
|
try:
|
|
if not re.match(pattern + '$', arg):
|
|
break
|
|
except re.error:
|
|
# DENY: Badly-formed filter
|
|
return False
|
|
else:
|
|
# ALLOW: All arguments matched
|
|
return True
|
|
|
|
# DENY: Some arguments did not match
|
|
return False
|
|
|
|
|
|
class DnsmasqFilter(CommandFilter):
|
|
"""Specific filter for the dnsmasq call (which includes env)"""
|
|
|
|
def match(self, userargs):
|
|
if (userargs[0].startswith("FLAGFILE=") and
|
|
userargs[1].startswith("NETWORK_ID=") and
|
|
userargs[2] == "dnsmasq"):
|
|
return True
|
|
return False
|
|
|
|
def get_command(self, userargs):
|
|
return [self.exec_path] + userargs[3:]
|
|
|
|
def get_environment(self, userargs):
|
|
env = os.environ.copy()
|
|
env['FLAGFILE'] = userargs[0].split('=')[-1]
|
|
env['NETWORK_ID'] = userargs[1].split('=')[-1]
|
|
return env
|
|
|
|
|
|
class KillFilter(CommandFilter):
|
|
"""Specific filter for the kill calls.
|
|
1st argument is a list of accepted signals (emptystring means no signal)
|
|
2nd argument is a list of accepted affected executables.
|
|
|
|
This filter relies on /proc to accurately determine affected
|
|
executable, so it will only work on procfs-capable systems (not OSX).
|
|
"""
|
|
|
|
def match(self, userargs):
|
|
if userargs[0] != "kill":
|
|
return False
|
|
args = list(userargs)
|
|
if len(args) == 3:
|
|
signal = args.pop(1)
|
|
if signal not in self.args[0]:
|
|
# Requested signal not in accepted list
|
|
return False
|
|
else:
|
|
if len(args) != 2:
|
|
# Incorrect number of arguments
|
|
return False
|
|
if '' not in self.args[0]:
|
|
# No signal, but list doesn't include empty string
|
|
return False
|
|
try:
|
|
command = os.readlink("/proc/%d/exe" % int(args[1]))
|
|
if command not in self.args[1]:
|
|
# Affected executable not in accepted list
|
|
return False
|
|
except (ValueError, OSError):
|
|
# Incorrect PID
|
|
return False
|
|
return True
|
|
|
|
|
|
class ReadFileFilter(CommandFilter):
|
|
"""Specific filter for the utils.read_file_as_root call"""
|
|
|
|
def __init__(self, file_path, *args):
|
|
self.file_path = file_path
|
|
super(ReadFileFilter, self).__init__("/bin/cat", "root", *args)
|
|
|
|
def match(self, userargs):
|
|
if userargs[0] != 'cat':
|
|
return False
|
|
if userargs[1] != self.file_path:
|
|
return False
|
|
if len(userargs) != 2:
|
|
return False
|
|
return True
|