vmware-nsx/bin/quantum-rootwrap
Thierry Carrez 39e4c97856 Restore SIGPIPE default action for subprocesses
Python ignores SIGPIPE on startup, because it prefers to check every
write and raise an IOError exception rather than taking the signal. Most
Unix subprocesses don't expect to work this way. This patch (adapted
from Colin Watson's post at http://tinyurl.com/2a7mzh5) sets SIGPIPE
back to the default action for quantum.agent.linux.utils.execute,
quantum.common.utils.execute and quantum-rootwrap created subprocesses.

Fixes bug 1053364

Change-Id: Ib805f1f8846c245b75a5ea64278c840b823c1fb2
2012-09-20 15:22:47 +02:00

101 lines
3.4 KiB
Python
Executable File

#!/usr/bin/env 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.
"""Root wrapper for Quantum
Filters which commands quantum is allowed to run as another user.
To use this, you should set the following in quantum.conf and the
various .ini files for the agent plugins:
root_helper=sudo quantum-rootwrap /etc/quantum/rootwrap.conf
You also need to let the quantum user run quantum-rootwrap as root in
/etc/sudoers:
quantum ALL = (root) NOPASSWD: /usr/bin/quantum-rootwrap
/etc/quantum/rootwrap.conf *
Filter specs live in /etc/quantum/rootwrap.d/*.filters, or
other locations pointed to by /etc/quantum/rootwrap.conf.
To make allowed commands node-specific, your packaging should only
install apropriate .filters for commands which are needed on each
node.
"""
import ConfigParser
import os
import signal
import subprocess
import sys
RC_UNAUTHORIZED = 99
RC_NOCOMMAND = 98
RC_BADCONFIG = 97
def _subprocess_setup():
# Python installs a SIGPIPE handler by default. This is usually not what
# non-Python subprocesses expect.
signal.signal(signal.SIGPIPE, signal.SIG_DFL)
if __name__ == '__main__':
# Split arguments, require at least a command
execname = sys.argv.pop(0)
# argv[0] required; path to conf file
if len(sys.argv) < 2:
print "%s: %s" % (execname, "No command specified")
sys.exit(RC_NOCOMMAND)
configfile = sys.argv.pop(0)
userargs = sys.argv[:]
# Load configuration
config = ConfigParser.RawConfigParser()
config.read(configfile)
try:
filters_path = config.get("DEFAULT", "filters_path").split(",")
filters = None
except ConfigParser.Error:
print "%s: Incorrect configuration file: %s" % (execname, configfile)
sys.exit(RC_BADCONFIG)
# Add ../ to sys.path to allow running from branch
possible_topdir = os.path.normpath(os.path.join(os.path.abspath(execname),
os.pardir, os.pardir))
if os.path.exists(os.path.join(possible_topdir, "quantum", "__init__.py")):
sys.path.insert(0, possible_topdir)
from quantum.rootwrap import wrapper
# Execute command if it matches any of the loaded filters
filters = wrapper.load_filters(filters_path)
filtermatch = wrapper.match_filter(filters, userargs)
if filtermatch:
obj = subprocess.Popen(filtermatch.get_command(userargs),
stdin=sys.stdin,
stdout=sys.stdout,
stderr=sys.stderr,
preexec_fn=_subprocess_setup,
env=filtermatch.get_environment(userargs))
obj.wait()
sys.exit(obj.returncode)
print "Unauthorized command: %s" % ' '.join(userargs)
sys.exit(RC_UNAUTHORIZED)