Give native strings to selinux library functions. (#17184)

* Give native strings to selinux library functions.

SELinux takes pathnames as native strings.  That means we need to
convert to bytes on python2 and convert to text on python3.

Fixes #17155

* Read kitchen documentation, make module_utils params more like kitchen API

* Remove none nonstring strategy and add strict
* Raise TypeError on invalid nonstring strategy

* Document to_native()

* Make unittests for testing module_utils.text
This commit is contained in:
Toshio Kuratomi 2016-08-22 16:44:13 -07:00 committed by GitHub
parent 384a01fcff
commit 57701d7115
4 changed files with 242 additions and 29 deletions

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@ -0,0 +1,171 @@
# This code is part of Ansible, but is an independent component.
# This particular file snippet, and this file snippet only, is BSD licensed.
# Modules you write using this snippet, which is embedded dynamically by Ansible
# still belong to the author of the module, and may assign their own license
# to the complete work.
#
# Copyright (c), Toshio Kuratomi <a.badger@gmail.com>, 2016
#
# Redistribution and use in source and binary forms, with or without modification,
# are permitted provided that the following conditions are met:
#
# * Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
# this list of conditions and the following disclaimer in the documentation
# and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
# USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
"""
.. warn:: This module_util is currently internal implementation.
We want to evaluate this code for stability and API suitability before
making backwards compatibility guarantees. The API may change between
releases. Do not use this unless you are willing to port your module code.
"""
from ansible.module_utils.six import PY3, text_type, binary_type
def to_bytes(obj, encoding='utf-8', errors=None, nonstring='simplerepr'):
"""Make sure that a string is a byte string
:arg obj: An object to make sure is a byte string. In most cases this
will be either a text string or a byte string. However, with
``nonstring='simplerepr'``, this can be used as a traceback-free
version of ``str(obj)``.
:kwarg encoding: The encoding to use to transform from a text string to
a byte string. Defaults to using 'utf-8'.
:kwarg errors: The error handler to use if the text string is not
encodable using the specified encoding. Any valid `codecs error
handler <https://docs.python.org/2/library/codecs.html#codec-base-classes>`_
may be specified. On Python3 this defaults to 'surrogateescape'. On
Python2, this defaults to 'replace'.
:kwarg nonstring: The strategy to use if a nonstring is specified in
``obj``. Default is 'simplerepr'. Valid values are:
:simplerepr: The default. This takes the ``str`` of the object and
then returns the bytes version of that string.
:empty: Return an empty byte string
:passthru: Return the object passed in
:strict: Raise a :exc:`TypeError`
:returns: Typically this returns a byte string. If a nonstring object is
passed in this may be a different type depending on the strategy
specified by nonstring. This will never return a text string.
.. note:: If passed a byte string, this function does not check that the
string is valid in the specified encoding. If it's important that the
byte string is in the specified encoding do::
encoded_string = to_bytes(to_text(input_string, 'latin-1'), 'utf-8')
"""
if isinstance(obj, binary_type):
return obj
if errors is None:
if PY3:
errors = 'surrogateescape'
else:
errors = 'replace'
if isinstance(obj, text_type):
return obj.encode(encoding, errors)
# Note: We do these last even though we have to call to_bytes again on the
# value because we're optimizing the common case
if nonstring == 'simplerepr':
value = str(obj)
elif nonstring == 'passthru':
return obj
elif nonstring == 'empty':
# python2.4 doesn't have b''
return to_bytes('')
elif nonstring == 'strict':
raise TypeError('obj must be a string type')
else:
raise TypeError('Invalid value %s for to_bytes\' nonstring parameter' % nonstring)
return to_bytes(value, encoding, errors)
def to_text(obj, encoding='utf-8', errors=None, nonstring='simplerepr'):
"""Make sure that a string is a text string
:arg obj: An object to make sure is a text string. In most cases this
will be either a text string or a byte string. However, with
``nonstring='simplerepr'``, this can be used as a traceback-free
version of ``str(obj)``.
:kwarg encoding: The encoding to use to transform from a byte string to
a text string. Defaults to using 'utf-8'.
:kwarg errors: The error handler to use if the byte string is not
decodable using the specified encoding. Any valid `codecs error
handler <https://docs.python.org/2/library/codecs.html#codec-base-classes>`_
may be specified. On Python3 this defaults to 'surrogateescape'. On
Python2, this defaults to 'replace'.
:kwarg nonstring: The strategy to use if a nonstring is specified in
``obj``. Default is 'simplerepr'. Valid values are:
:simplerepr: The default. This takes the ``str`` of the object and
then returns the text version of that string.
:empty: Return an empty text string
:passthru: Return the object passed in
:strict: Raise a :exc:`TypeError`
:returns: Typically this returns a text string. If a nonstring object is
passed in this may be a different type depending on the strategy
specified by nonstring. This will never return a byte string.
"""
if isinstance(obj, text_type):
return obj
if errors is None:
if PY3:
errors = 'surrogateescape'
else:
errors = 'replace'
if isinstance(obj, binary_type):
return obj.decode(encoding, errors)
# Note: We do these last even though we have to call to_text again on the
# value because we're optimizing the common case
if nonstring == 'simplerepr':
value = str(obj)
elif nonstring == 'passthru':
return obj
elif nonstring == 'empty':
return u''
elif nonstring == 'strict':
raise TypeError('obj must be a string type')
else:
raise TypeError('Invalid value %s for to_text\'s nonstring parameter' % nonstring)
return to_text(value, encoding, errors)
#: :py:func:`to_native`
#: Transform a variable into the native str type for the python version
#:
#: On Python2, this is an alias for
#: :func:`~ansible.module_utils.to_bytes`. On Python3 it is an alias for
#: :func:`~ansible.module_utils.to_text`. It makes it easier to
#: transform a variable into the native str type for the python version
#: the code is running on. Use this when constructing the message to
#: send to exceptions or when dealing with an API that needs to take
#: a native string. Example::
#:
#: try:
#: 1//0
#: except ZeroDivisionError as e:
#: raise MyException('Encountered and error: %s' % to_native(e))
if PY3:
to_native = to_text
else:
to_native = to_bytes

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@ -181,6 +181,7 @@ from ansible.module_utils.six import (PY2, PY3, b, binary_type, integer_types,
iteritems, text_type, string_types)
from ansible.module_utils.six.moves import map, reduce
from ansible.module_utils.pycompat24 import get_exception
from ansible.module_utils._text import to_native
_NUMBERTYPES = tuple(list(integer_types) + [float])
@ -773,26 +774,13 @@ class AnsibleModule(object):
context.append(None)
return context
def _to_filesystem_str(self, path):
'''Returns filesystem path as a str, if it wasn't already.
Used in selinux interactions because it cannot accept unicode
instances, and specifying complex args in a playbook leaves
you with unicode instances. This method currently assumes
that your filesystem encoding is UTF-8.
'''
if isinstance(path, text_type):
path = path.encode("utf-8")
return path
# If selinux fails to find a default, return an array of None
def selinux_default_context(self, path, mode=0):
context = self.selinux_initial_context()
if not HAVE_SELINUX or not self.selinux_enabled():
return context
try:
ret = selinux.matchpathcon(self._to_filesystem_str(path), mode)
ret = selinux.matchpathcon(to_native(path, 'strict'), mode)
except OSError:
return context
if ret[0] == -1:
@ -807,7 +795,7 @@ class AnsibleModule(object):
if not HAVE_SELINUX or not self.selinux_enabled():
return context
try:
ret = selinux.lgetfilecon_raw(self._to_filesystem_str(path))
ret = selinux.lgetfilecon_raw(to_native(path, 'strict'))
except OSError:
e = get_exception()
if e.errno == errno.ENOENT:
@ -895,7 +883,7 @@ class AnsibleModule(object):
try:
if self.check_mode:
return True
rc = selinux.lsetfilecon(self._to_filesystem_str(path),
rc = selinux.lsetfilecon(to_native(path),
str(':'.join(new_context)))
except OSError:
e = get_exception()

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@ -0,0 +1,65 @@
# -*- coding: utf-8 -*-
# (c) 2016 Toshio Kuratomi <tkuratomi@ansible.com>
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible. If not, see <http://www.gnu.org/licenses/>.
# Make coding more python3-ish
from __future__ import (absolute_import, division)
__metaclass__ = type
from ansible.compat.six import PY3
from ansible.compat.tests import unittest
from units.mock.generator import add_method
# Internal API while this is still being developed. Eventually move to
# module_utils.text
from ansible.module_utils._text import to_text, to_bytes, to_native
# Format: byte representation, text representation, encoding of byte representation
VALID_STRINGS = (
(b'abcde', u'abcde', 'ascii'),
(b'caf\xc3\xa9', u'caf\xe9', 'utf-8'),
(b'caf\xe9', u'caf\xe9', 'latin-1'),
# u'くらとみ'
(b'\xe3\x81\x8f\xe3\x82\x89\xe3\x81\xa8\xe3\x81\xbf', u'\u304f\u3089\u3068\u307f', 'utf-8'),
(b'\x82\xad\x82\xe7\x82\xc6\x82\xdd', u'\u304f\u3089\u3068\u307f', 'shift-jis'),
)
def _check_to_text(self, in_string, encoding, expected):
"""test happy path of decoding to text"""
self.assertEqual(to_text(in_string, encoding), expected)
def _check_to_bytes(self, in_string, encoding, expected):
"""test happy path of encoding to bytes"""
self.assertEqual(to_bytes(in_string, encoding), expected)
def _check_to_native(self, in_string, encoding, py2_expected, py3_expected):
"""test happy path of encoding to native strings"""
if PY3:
self.assertEqual(to_native(in_string, encoding), py3_expected)
else:
self.assertEqual(to_native(in_string, encoding), py2_expected)
@add_method(_check_to_text, [(i[0], i[2], i[1]) for i in VALID_STRINGS])
@add_method(_check_to_text, [(i[1], i[2], i[1]) for i in VALID_STRINGS])
@add_method(_check_to_bytes, [(i[0], i[2], i[0]) for i in VALID_STRINGS])
@add_method(_check_to_bytes, [(i[1], i[2], i[0]) for i in VALID_STRINGS])
@add_method(_check_to_native, [(i[0], i[2], i[0], i[1]) for i in VALID_STRINGS])
@add_method(_check_to_native, [(i[1], i[2], i[0], i[1]) for i in VALID_STRINGS])
class TestModuleUtilsText(unittest.TestCase):
pass

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@ -580,17 +580,6 @@ class TestModuleUtilsBasic(ModuleTestCase):
self.assertEqual(am.is_special_selinux_path('/some/path/that/should/be/nfs'), (True, ['foo_u', 'foo_r', 'foo_t', 's0']))
self.assertEqual(am.is_special_selinux_path('/weird/random/fstype/path'), (True, ['foo_u', 'foo_r', 'foo_t', 's0']))
def test_module_utils_basic_ansible_module_to_filesystem_str(self):
from ansible.module_utils import basic
basic._ANSIBLE_ARGS = None
am = basic.AnsibleModule(
argument_spec = dict(),
)
self.assertEqual(am._to_filesystem_str(u'foo'), b'foo')
self.assertEqual(am._to_filesystem_str(u'föö'), b'f\xc3\xb6\xc3\xb6')
def test_module_utils_basic_ansible_module_user_and_group(self):
from ansible.module_utils import basic
@ -653,7 +642,7 @@ class TestModuleUtilsBasic(ModuleTestCase):
with patch.dict('sys.modules', {'selinux': basic.selinux}):
with patch('selinux.lsetfilecon', return_value=0) as m:
self.assertEqual(am.set_context_if_different('/path/to/file', ['foo_u', 'foo_r', 'foo_t', 's0'], False), True)
m.assert_called_with(b'/path/to/file', 'foo_u:foo_r:foo_t:s0')
m.assert_called_with('/path/to/file', 'foo_u:foo_r:foo_t:s0')
m.reset_mock()
am.check_mode = True
self.assertEqual(am.set_context_if_different('/path/to/file', ['foo_u', 'foo_r', 'foo_t', 's0'], False), True)
@ -670,7 +659,7 @@ class TestModuleUtilsBasic(ModuleTestCase):
with patch('selinux.lsetfilecon', return_value=0) as m:
self.assertEqual(am.set_context_if_different('/path/to/file', ['foo_u', 'foo_r', 'foo_t', 's0'], False), True)
m.assert_called_with(b'/path/to/file', 'sp_u:sp_r:sp_t:s0')
m.assert_called_with('/path/to/file', 'sp_u:sp_r:sp_t:s0')
delattr(basic, 'selinux')