openstack/designate
Code Issues Proposed changes

Switch to oslo.rootwrap

Browse Source 
Change-Id: I3f69edfd96aa0bf60e5321560706e12074fc0c58
This commit is contained in:
Endre Karlson 2014-02-20 13:29:12 +01:00 committed by Kiall Mac Innes
parent daf03c3a73
commit 894f24f165
7 changed files with 3 additions and 623 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

0
designate/openstack/common/rootwrap/__init__.py
View File

136
designate/openstack/common/rootwrap/cmd.py
View File

@ -1,136 +0,0 @@
# Copyright (c) 2011 OpenStack Foundation.
# 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 OpenStack services
Filters which commands a service is allowed to run as another user.
To use this with designate, you should set the following in
designate.conf:
rootwrap_config=/etc/designate/rootwrap.conf
You also need to let the designate user run designate-rootwrap
as root in sudoers:
designate ALL = (root) NOPASSWD: /usr/bin/designate-rootwrap
/etc/designate/rootwrap.conf *
Service packaging should deploy .filters files only on nodes where
they are needed, to avoid allowing more than is necessary.
"""
from __future__ import print_function
import ConfigParser
import logging
import os
import pwd
import signal
import subprocess
import sys
RC_UNAUTHORIZED = 99
RC_NOCOMMAND = 98
RC_BADCONFIG = 97
RC_NOEXECFOUND = 96
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)
def _exit_error(execname, message, errorcode, log=True):
print("%s: %s" % (execname, message), file=sys.stderr)
if log:
logging.error(message)
sys.exit(errorcode)
def _getlogin():
try:
return os.getlogin()
except OSError:
return (os.getenv('USER') or
os.getenv('USERNAME') or
os.getenv('LOGNAME'))
def main():
# Split arguments, require at least a command
execname = sys.argv.pop(0)
if len(sys.argv) < 2:
_exit_error(execname, "No command specified", RC_NOCOMMAND, log=False)
configfile = sys.argv.pop(0)
userargs = sys.argv[:]
# 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, "designate", "__init__.py")):
sys.path.insert(0, possible_topdir)
from designate.openstack.common.rootwrap import wrapper
# Load configuration
try:
rawconfig = ConfigParser.RawConfigParser()
rawconfig.read(configfile)
config = wrapper.RootwrapConfig(rawconfig)
except ValueError as exc:
msg = "Incorrect value in %s: %s" % (configfile, exc.message)
_exit_error(execname, msg, RC_BADCONFIG, log=False)
except ConfigParser.Error:
_exit_error(execname, "Incorrect configuration file: %s" % configfile,
RC_BADCONFIG, log=False)
if config.use_syslog:
wrapper.setup_syslog(execname,
config.syslog_log_facility,
config.syslog_log_level)
# Execute command if it matches any of the loaded filters
filters = wrapper.load_filters(config.filters_path)
try:
filtermatch = wrapper.match_filter(filters, userargs,
exec_dirs=config.exec_dirs)
if filtermatch:
command = filtermatch.get_command(userargs,
exec_dirs=config.exec_dirs)
if config.use_syslog:
logging.info("(%s > %s) Executing %s (filter match = %s)" % (
_getlogin(), pwd.getpwuid(os.getuid())[0],
command, filtermatch.name))
obj = subprocess.Popen(command,
stdin=sys.stdin,
stdout=sys.stdout,
stderr=sys.stderr,
preexec_fn=_subprocess_setup,
env=filtermatch.get_environment(userargs))
obj.wait()
sys.exit(obj.returncode)
except wrapper.FilterMatchNotExecutable as exc:
msg = ("Executable not found: %s (filter match = %s)"
% (exc.match.exec_path, exc.match.name))
_exit_error(execname, msg, RC_NOEXECFOUND, log=config.use_syslog)
except wrapper.NoFilterMatched:
msg = ("Unauthorized command: %s (no filter matched)"
% ' '.join(userargs))
_exit_error(execname, msg, RC_UNAUTHORIZED, log=config.use_syslog)

316
designate/openstack/common/rootwrap/filters.py
View File

@ -1,316 +0,0 @@
# Copyright (c) 2011 OpenStack Foundation.
# 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.name = ''
self.exec_path = exec_path
self.run_as = run_as
self.args = args
self.real_exec = None
def get_exec(self, exec_dirs=[]):
"""Returns existing executable, or empty string if none found."""
if self.real_exec is not None:
return self.real_exec
self.real_exec = ""
if os.path.isabs(self.exec_path):
if os.access(self.exec_path, os.X_OK):
self.real_exec = self.exec_path
else:
for binary_path in exec_dirs:
expanded_path = os.path.join(binary_path, self.exec_path)
if os.access(expanded_path, os.X_OK):
self.real_exec = expanded_path
break
return self.real_exec
def match(self, userargs):
"""Only check that the first argument (command) matches exec_path."""
return userargs and os.path.basename(self.exec_path) == userargs[0]
def get_command(self, userargs, exec_dirs=[]):
"""Returns command to execute (with sudo -u if run_as != root)."""
to_exec = self.get_exec(exec_dirs=exec_dirs) or self.exec_path
if (self.run_as != 'root'):
# Used to run commands at lesser privileges
return ['sudo', '-u', self.run_as, to_exec] + userargs[1:]
return [to_exec] + 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 (not userargs or 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 PathFilter(CommandFilter):
"""Command filter checking that path arguments are within given dirs
One can specify the following constraints for command arguments:
1) pass - pass an argument as is to the resulting command
2) some_str - check if an argument is equal to the given string
3) abs path - check if a path argument is within the given base dir
A typical rootwrapper filter entry looks like this:
# cmdname: filter name, raw command, user, arg_i_constraint [, ...]
chown: PathFilter, /bin/chown, root, nova, /var/lib/images
"""
def match(self, userargs):
if not userargs or len(userargs) < 2:
return False
command, arguments = userargs[0], userargs[1:]
equal_args_num = len(self.args) == len(arguments)
exec_is_valid = super(PathFilter, self).match(userargs)
args_equal_or_pass = all(
arg == 'pass' or arg == value
for arg, value in zip(self.args, arguments)
if not os.path.isabs(arg) # arguments not specifying abs paths
)
paths_are_within_base_dirs = all(
os.path.commonprefix([arg, os.path.realpath(value)]) == arg
for arg, value in zip(self.args, arguments)
if os.path.isabs(arg) # arguments specifying abs paths
)
return (equal_args_num and
exec_is_valid and
args_equal_or_pass and
paths_are_within_base_dirs)
def get_command(self, userargs, exec_dirs=[]):
command, arguments = userargs[0], userargs[1:]
# convert path values to canonical ones; copy other args as is
args = [os.path.realpath(value) if os.path.isabs(arg) else value
for arg, value in zip(self.args, arguments)]
return super(PathFilter, self).get_command([command] + args,
exec_dirs)
class KillFilter(CommandFilter):
"""Specific filter for the kill calls.
1st argument is the user to run /bin/kill under
2nd argument is the location of the affected executable
if the argument is not absolute, it is checked against $PATH
Subsequent arguments list the accepted signals (if any)
This filter relies on /proc to accurately determine affected
executable, so it will only work on procfs-capable systems (not OSX).
"""
def __init__(self, *args):
super(KillFilter, self).__init__("/bin/kill", *args)
def match(self, userargs):
if not userargs or userargs[0] != "kill":
return False
args = list(userargs)
if len(args) == 3:
# A specific signal is requested
signal = args.pop(1)
if signal not in self.args[1:]:
# Requested signal not in accepted list
return False
else:
if len(args) != 2:
# Incorrect number of arguments
return False
if len(self.args) > 1:
# No signal requested, but filter requires specific signal
return False
try:
command = os.readlink("/proc/%d/exe" % int(args[1]))
except (ValueError, OSError):
# Incorrect PID
return False
# NOTE(yufang521247): /proc/PID/exe may have '\0' on the
# end, because python doesn't stop at '\0' when read the
# target path.
command = command.partition('\0')[0]
# NOTE(dprince): /proc/PID/exe may have ' (deleted)' on
# the end if an executable is updated or deleted
if command.endswith(" (deleted)"):
command = command[:-len(" (deleted)")]
kill_command = self.args[0]
if os.path.isabs(kill_command):
return kill_command == command
return (os.path.isabs(command) and
kill_command == os.path.basename(command) and
os.path.dirname(command) in os.environ.get('PATH', ''
).split(':'))
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):
return (userargs == ['cat', self.file_path])
class IpFilter(CommandFilter):
"""Specific filter for the ip utility to that does not match exec."""
def match(self, userargs):
if userargs[0] == 'ip':
if userargs[1] == 'netns':
return (userargs[2] in ('list', 'add', 'delete'))
else:
return True
class EnvFilter(CommandFilter):
"""Specific filter for the env utility.
Behaves like CommandFilter, except that it handles
leading env A=B.. strings appropriately.
"""
def _extract_env(self, arglist):
"""Extract all leading NAME=VALUE arguments from arglist."""
envs = set()
for arg in arglist:
if '=' not in arg:
break
envs.add(arg.partition('=')[0])
return envs
def __init__(self, exec_path, run_as, *args):
super(EnvFilter, self).__init__(exec_path, run_as, *args)
env_list = self._extract_env(self.args)
# Set exec_path to X when args are in the form of
# env A=a B=b C=c X Y Z
if "env" in exec_path and len(env_list) < len(self.args):
self.exec_path = self.args[len(env_list)]
def match(self, userargs):
# ignore leading 'env'
if userargs[0] == 'env':
userargs.pop(0)
# require one additional argument after configured ones
if len(userargs) < len(self.args):
return False
# extract all env args
user_envs = self._extract_env(userargs)
filter_envs = self._extract_env(self.args)
user_command = userargs[len(user_envs):len(user_envs) + 1]
# match first non-env argument with CommandFilter
return (super(EnvFilter, self).match(user_command)
and len(filter_envs) and user_envs == filter_envs)
def exec_args(self, userargs):
args = userargs[:]
# ignore leading 'env'
if args[0] == 'env':
args.pop(0)
# Throw away leading NAME=VALUE arguments
while args and '=' in args[0]:
args.pop(0)
return args
def get_command(self, userargs, exec_dirs=[]):
to_exec = self.get_exec(exec_dirs=exec_dirs) or self.exec_path
return [to_exec] + self.exec_args(userargs)[1:]
def get_environment(self, userargs):
env = os.environ.copy()
# ignore leading 'env'
if userargs[0] == 'env':
userargs.pop(0)
# Handle leading NAME=VALUE pairs
for a in userargs:
env_name, equals, env_value = a.partition('=')
if not equals:
break
if env_name and env_value:
env[env_name] = env_value
return env
class ChainingFilter(CommandFilter):
def exec_args(self, userargs):
return []
class IpNetnsExecFilter(ChainingFilter):
"""Specific filter for the ip utility to that does match exec."""
def match(self, userargs):
# Network namespaces currently require root
# require <ns> argument
if self.run_as != "root" or len(userargs) < 4:
return False
return (userargs[:3] == ['ip', 'netns', 'exec'])
def exec_args(self, userargs):
args = userargs[4:]
if args:
args[0] = os.path.basename(args[0])
return args

169
designate/openstack/common/rootwrap/wrapper.py
View File

@ -1,169 +0,0 @@
# Copyright (c) 2011 OpenStack Foundation.
# 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 logging
import logging.handlers
import os
import string
from six import moves
from designate.openstack.common.rootwrap import filters
class NoFilterMatched(Exception):
"""This exception is raised when no filter matched."""
pass
class FilterMatchNotExecutable(Exception):
"""Raised when a filter matched but no executable was found."""
def __init__(self, match=None, **kwargs):
self.match = match
class RootwrapConfig(object):
def __init__(self, config):
# filters_path
self.filters_path = config.get("DEFAULT", "filters_path").split(",")
# exec_dirs
if config.has_option("DEFAULT", "exec_dirs"):
self.exec_dirs = config.get("DEFAULT", "exec_dirs").split(",")
else:
self.exec_dirs = []
# Use system PATH if exec_dirs is not specified
if "PATH" in os.environ:
self.exec_dirs = os.environ['PATH'].split(':')
# syslog_log_facility
if config.has_option("DEFAULT", "syslog_log_facility"):
v = config.get("DEFAULT", "syslog_log_facility")
facility_names = logging.handlers.SysLogHandler.facility_names
self.syslog_log_facility = getattr(logging.handlers.SysLogHandler,
v, None)
if self.syslog_log_facility is None and v in facility_names:
self.syslog_log_facility = facility_names.get(v)
if self.syslog_log_facility is None:
raise ValueError('Unexpected syslog_log_facility: %s' % v)
else:
default_facility = logging.handlers.SysLogHandler.LOG_SYSLOG
self.syslog_log_facility = default_facility
# syslog_log_level
if config.has_option("DEFAULT", "syslog_log_level"):
v = config.get("DEFAULT", "syslog_log_level")
self.syslog_log_level = logging.getLevelName(v.upper())
if (self.syslog_log_level == "Level %s" % v.upper()):
raise ValueError('Unexpected syslog_log_level: %s' % v)
else:
self.syslog_log_level = logging.ERROR
# use_syslog
if config.has_option("DEFAULT", "use_syslog"):
self.use_syslog = config.getboolean("DEFAULT", "use_syslog")
else:
self.use_syslog = False
# use_syslog_rfc_format
if config.has_option("DEFAULT", "use_syslog_rfc_format"):
self.use_syslog_rfc_format = config.getboolean(
"DEFAULT", "use_syslog_rfc_format")
else:
self.use_syslog_rfc_format = False
def setup_syslog(execname, facility, level):
rootwrap_logger = logging.getLogger()
rootwrap_logger.setLevel(level)
handler = logging.handlers.SysLogHandler(address='/dev/log',
facility=facility)
handler.setFormatter(logging.Formatter(
os.path.basename(execname) + ': %(message)s'))
rootwrap_logger.addHandler(handler)
def build_filter(class_name, *args):
"""Returns a filter object of class class_name."""
if not hasattr(filters, class_name):
logging.warning("Skipping unknown filter class (%s) specified "
"in filter definitions" % class_name)
return None
filterclass = getattr(filters, class_name)
return filterclass(*args)
def load_filters(filters_path):
"""Load filters from a list of directories."""
filterlist = []
for filterdir in filters_path:
if not os.path.isdir(filterdir):
continue
for filterfile in filter(lambda f: not f.startswith('.'),
os.listdir(filterdir)):
filterconfig = moves.configparser.RawConfigParser()
filterconfig.read(os.path.join(filterdir, filterfile))
for (name, value) in filterconfig.items("Filters"):
filterdefinition = [string.strip(s) for s in value.split(',')]
newfilter = build_filter(*filterdefinition)
if newfilter is None:
continue
newfilter.name = name
filterlist.append(newfilter)
return filterlist
def match_filter(filter_list, userargs, exec_dirs=[]):
"""Checks user command and arguments through command filters.
Returns the first matching filter.
Raises NoFilterMatched if no filter matched.
Raises FilterMatchNotExecutable if no executable was found for the
best filter match.
"""
first_not_executable_filter = None
for f in filter_list:
if f.match(userargs):
if isinstance(f, filters.ChainingFilter):
# This command calls exec verify that remaining args
# matches another filter.
def non_chain_filter(fltr):
return (fltr.run_as == f.run_as
and not isinstance(fltr, filters.ChainingFilter))
leaf_filters = [fltr for fltr in filter_list
if non_chain_filter(fltr)]
args = f.exec_args(userargs)
if (not args or not match_filter(leaf_filters,
args, exec_dirs=exec_dirs)):
continue
# Try other filters if executable is absent
if not f.get_exec(exec_dirs=exec_dirs):
if not first_not_executable_filter:
first_not_executable_filter = f
continue
# Otherwise return matching filter for execution
return f
if first_not_executable_filter:
# A filter matched, but no executable was found for it
raise FilterMatchNotExecutable(match=first_not_executable_filter)
# No filter matched
raise NoFilterMatched()

2
etc/designate/designate.conf.sample
View File

@ -20,7 +20,7 @@ debug = False
# Use "sudo designate-rootwrap /etc/designate/rootwrap.conf" to use the real # Use "sudo designate-rootwrap /etc/designate/rootwrap.conf" to use the real
# root filter facility. # root filter facility.
# Change to "sudo" to skip the filtering and just run the comand directly # Change to "sudo" to skip the filtering and just run the comand directly
root_helper = sudo # root_helper = sudo designate-rootwrap /etc/designate/rootwrap.conf
# Which networking API to use, Defaults to neutron # Which networking API to use, Defaults to neutron
# network_api = neutron # network_api = neutron

1
requirements.txt
View File

@ -8,6 +8,7 @@ jsonschema>=2.0.0,<3.0.0
kombu>=2.4.8 kombu>=2.4.8
netaddr>=0.7.6 netaddr>=0.7.6
oslo.config>=1.2.0 oslo.config>=1.2.0
oslo.rootwrap
Paste Paste
PasteDeploy>=1.5.0 PasteDeploy>=1.5.0
pbr>=0.6,<1.0 pbr>=0.6,<1.0

2
setup.cfg
View File

@ -28,11 +28,11 @@ setup-hooks =
packages = packages =
designate designate
scripts = scripts =
bin/designate-rootwrap
bin/designate-rpc-zmq-receiver bin/designate-rpc-zmq-receiver
[entry_points] [entry_points]
console_scripts = console_scripts =
designate-rootwrap = oslo.rootwrap.cmd:main
designate-agent = designate.cmd.agent:main designate-agent = designate.cmd.agent:main
designate-api = designate.cmd.api:main designate-api = designate.cmd.api:main
designate-central = designate.cmd.central:main designate-central = designate.cmd.central:main