CasperSecurity
# Copyright © 2012 Piotr Ożarowski <piotr@debian.org>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
import logging
import os
import re
from os.path import join, split
from debpython import execute
from debpython.version import Version
SHEBANG_RE = re.compile(r'''
(?:\#!\s*){0,1} # shebang prefix
(?P<path>
.*?/bin/.*?)?
(?P<name>
python|pypy)
(?P<version>
\d[\.\d]*)?
(?P<debug>
-dbg)?
(?P<options>.*)
''', re.VERBOSE)
EXTFILE_RE = re.compile(r'''
(?P<name>.*?)
(?:\.
(?P<stableabi>abi\d+)
|(?:\.
(?P<soabi>
(?P<impl>cpython|pypy)
-
(?P<ver>\d{2})
(?P<flags>[a-z]*?)
)
(?:
-(?P<multiarch>[^/]*?)
)?
))?
(?P<debug>_d)?
\.so$''', re.VERBOSE)
log = logging.getLogger(__name__)
class Interpreter:
path = None
name = 'python'
version = None
debug = False
impl = 'cpython' # implementation
options = ()
_cache = {}
def __init__(self, value=None, path=None, name=None, version=None,
debug=None, impl=None, options=None):
params = locals()
del params['self']
del params['value']
if isinstance(value, Interpreter):
for key in params.keys():
if params[key] is None:
params[key] = getattr(value, key)
elif value:
if value.replace('.', '').isdigit() and not version:
params['version'] = Version(value)
else:
for key, val in self.parse(value).items():
if params[key] is None:
params[key] = val
for key, val in params.items():
setattr(self, key, val)
def __setattr__(self, name, value):
if name == 'name' and value:
if value.startswith('python'):
self.__dict__['impl'] = 'cpython'
elif value.startswith('pypy'):
self.__dict__['impl'] = 'pypy'
if '-dbg' in value:
self.__dict__['debug'] = True
elif name == 'version' and value is not None:
value = Version(value)
if name in ('name', 'impl', 'debug', 'options') and value is None:
# get the class default instead
self.__dict__[name] = getattr(Interpreter, name)
else:
self.__dict__[name] = value
def __repr__(self):
result = self.path or ''
result += self._vstr(self.version)
if self.options:
result += ' ' + ' '.join(self.options)
return result
def __str__(self):
return self._vstr(self.version)
def _vstr(self, version):
if self.impl == 'pypy':
# TODO: will Debian support more than one PyPy version?
return self.name
if version and str(version) not in self.name:
if self.debug:
return 'python{}-dbg'.format(version)
return self.name + str(version)
return self.name
@staticmethod
def parse(shebang):
"""Return dict with parsed shebang
>>> sorted(Interpreter.parse('pypy').items())
[('debug', None), ('name', 'pypy'), ('options', ()), ('path', None), ('version', None)]
>>> sorted(Interpreter.parse('/usr/bin/python3.3-dbg').items())
[('debug', '-dbg'), ('name', 'python'), ('options', ()), ('path', '/usr/bin/'), ('version', '3.3')]
>>> sorted(Interpreter.parse('#! /usr/bin/pypy --foo').items())
[('debug', None), ('name', 'pypy'), ('options', ('--foo',)), ('path', '/usr/bin/'), ('version', None)]
>>> sorted(Interpreter.parse('#! /usr/bin/python3.2').items())
[('debug', None), ('name', 'python'), ('options', ()), ('path', '/usr/bin/'), ('version', '3.2')]
>>> sorted(Interpreter.parse('/usr/bin/python3.2-dbg --foo --bar').items())
[('debug', '-dbg'), ('name', 'python'), ('options', ('--foo', '--bar')),\
('path', '/usr/bin/'), ('version', '3.2')]
"""
result = SHEBANG_RE.search(shebang)
if not result:
return {}
result = result.groupdict()
if 'options' in result:
# TODO: do we need "--key value" here?
result['options'] = tuple(result['options'].split())
return result
def sitedir(self, gdb=False, package=None, version=None):
"""Return path to site-packages directory.
Note that returned path is not the final location of .py files
>>> i = Interpreter('python')
>>> i.sitedir(version='3.1')
'/usr/lib/python3/dist-packages/'
>>> i.sitedir(version='2.5')
'/usr/lib/python2.5/site-packages/'
>>> i.sitedir(version=Version('2.7'))
'/usr/lib/python2.7/dist-packages/'
>>> i.sitedir(version='3.1', gdb=True, package='python3-foo')
'debian/python3-foo/usr/lib/debug/usr/lib/python3/dist-packages/'
>>> i.sitedir(version=Version('3.2'))
'/usr/lib/python3/dist-packages/'
>>> Interpreter('pypy').sitedir(version='2.0')
'/usr/lib/pypy/dist-packages/'
"""
version = Version(version or self.version)
#if not version:
# version = Version(DEFAULT)
if self.impl == 'pypy':
path = '/usr/lib/pypy/dist-packages/'
elif version << Version('2.6'):
path = "/usr/lib/python%s/site-packages/" % version
elif version << Version('3.0'):
path = "/usr/lib/python%s/dist-packages/" % version
else:
path = '/usr/lib/python3/dist-packages/'
if gdb:
path = "/usr/lib/debug%s" % path
if package:
path = "debian/%s%s" % (package, path)
return path
def cache_file(self, fpath, version=None):
"""Given path to a .py file, return path to its .pyc/.pyo file.
This function is inspired by Python 3.2's imp.cache_from_source.
:param fpath: path to file name
:param version: Python version
>>> i = Interpreter('python')
>>> i.cache_file('foo.py', Version('3.1'))
'foo.pyc'
>>> i.cache_file('bar/foo.py', '3.2')
'bar/__pycache__/foo.cpython-32.pyc'
"""
version = Version(version or self.version)
last_char = 'o' if '-O' in self.options else 'c'
if version <= Version('3.1'):
return fpath + last_char
fdir, fname = split(fpath)
if not fname.endswith('.py'):
fname += '.py'
return join(fdir, '__pycache__', "%s.%s.py%s" %
(fname[:-3], self.magic_tag(version), last_char))
def ext_file(self, name, version=None):
"""Return extension name with soname and multiarch tags."""
version = Version(version or self.version)
soabi, multiarch = self._get_config(version)
result = name.split('.', 1)[0]
if soabi:
result += '.{}'.format(soabi)
if multiarch:
result += '-{}'.format(multiarch)
if self.debug and self.impl == 'cpython'\
and version << Version('3'):
result += '_d'
return '{}.so'.format(result)
def magic_number(self, version=None):
"""Return magic number."""
version = Version(version or self.version)
if self.impl == 'cpython' and version << Version('3'):
return ''
result = self._execute('import imp; print(imp.get_magic())', version)
return eval(result)
def magic_tag(self, version=None):
"""Return Python magic tag (used in __pycache__ dir to tag files).
>>> i = Interpreter('python')
>>> i.magic_tag(version='3.2')
'cpython-32'
"""
version = Version(version or self.version)
if self.impl == 'cpython' and version << Version('3.2'):
return ''
return self._execute('import imp; print(imp.get_tag())', version)
def multiarch(self, version=None):
"""Return multiarch tag."""
version = Version(version or self.version)
try:
soabi, multiarch = self._get_config(version)
except Exception:
log.debug('cannot get multiarch', exc_info=True)
# interpreter without multiach support
return ''
return multiarch
def stableabi(self, version=None):
version = Version(version or self.version)
# stable ABI was introduced in Python 3.3
if self.impl == 'cpython' and version >> Version('3.2'):
return 'abi{}'.format(version.major)
def soabi(self, version=None):
"""Return SOABI flag (used to in .so files).
>>> i = Interpreter('python')
>>> i.soabi(version=Version('3.3'))
'cpython-33m'
"""
version = Version(version or self.version)
# NOTE: it's not the same as magic_tag
try:
soabi, multiarch = self._get_config(version)
except Exception:
log.debug('cannot get soabi', exc_info=True)
# interpreter without soabi support
return ''
return soabi
def check_extname(self, fname, version=None):
"""Return extension file name if file can be renamed.
>>> i = Interpreter('python')
>>> i.check_extname('foo.so', version='3.3') # doctest: +ELLIPSIS
'foo.cpython-33m-....so'
>>> i.check_extname('foo.abi3.so', version='3.3')
>>> i.check_extname('foo/bar/bazmodule.so', version='3.3') # doctest: +ELLIPSIS
'foo/bar/baz.cpython-33m-....so'
"""
version = Version(version or self.version)
if '/' in fname:
fdir, fname = fname.rsplit('/', 1) # in case full path was passed
else:
fdir = ''
info = EXTFILE_RE.search(fname)
if not info:
return
info = info.groupdict()
if info['stableabi']:
# files with stable ABI in name don't need changes
return
i = Interpreter(self, version=version)
if info['ver']:
i.version = "{}.{}".format(info['ver'][0], info['ver'][1])
if not i.debug and (info['debug'] or 'd' in (info['flags'] or '')):
i.debug = True
try:
soabi, multiarch = i._get_config()
except Exception:
log.debug('cannot get soabi/multiarch', exc_info=True)
return
result = info['name']
if i.impl == 'cpython' and i.version >> '3.2' and result.endswith('module'):
result = result[:-6]
if info['soabi'] or soabi:
result = "{}.{}".format(result, info['soabi'] or soabi)
if info['multiarch'] or multiarch:
result = "{}-{}".format(result, info['multiarch'] or multiarch)
result += '.so'
if fname == result:
return
return join(fdir, result)
def _get_config(self, version=None):
version = Version(version or self.version)
# sysconfig module is available since Python 3.2
# (also backported to Python 2.7)
if self.impl == 'pypy' or self.impl == 'cpython' and (
version >> '2.6' and version << '3'
or version >> '3.1' or version == '3'):
cmd = 'import sysconfig as s;'
else:
cmd = 'from distutils import sysconfig as s;'
cmd += 'print("__SEP__".join(i or "" ' \
'for i in s.get_config_vars("SOABI", "MULTIARCH")))'
conf_vars = self._execute(cmd, version).split('__SEP__')
try:
conf_vars[1] = os.environ['DEB_HOST_MULTIARCH']
except KeyError:
pass
return conf_vars
def _execute(self, command, version=None, cache=True):
version = Version(version or self.version)
command = "{} -c '{}'".format(self._vstr(version), command.replace("'", "\'"))
if cache and command in self.__class__._cache:
return self.__class__._cache[command]
output = execute(command)
if output['returncode'] != 0:
log.debug(output['stderr'])
raise Exception('{} failed with status code {}'.format(command, output['returncode']))
result = output['stdout'].splitlines()
if len(result) == 1:
result = result[0]
if cache:
self.__class__._cache[command] = result
return result