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Editing: sandbox.py
import os import sys import tempfile import operator import functools import itertools import re import contextlib import pickle import textwrap from setuptools.extern import six from setuptools.extern.six.moves import builtins, map import pkg_resources.py31compat if sys.platform.startswith('java'): import org.python.modules.posix.PosixModule as _os else: _os = sys.modules[os.name] try: _file = file except NameError: _file = None _open = open from distutils.errors import DistutilsError from pkg_resources import working_set __all__ = [ "AbstractSandbox", "DirectorySandbox", "SandboxViolation", "run_setup", ] def _execfile(filename, globals, locals=None): """ Python 3 implementation of execfile. """ mode = 'rb' with open(filename, mode) as stream: script = stream.read() if locals is None: locals = globals code = compile(script, filename, 'exec') exec(code, globals, locals) @contextlib.contextmanager def save_argv(repl=None): saved = sys.argv[:] if repl is not None: sys.argv[:] = repl try: yield saved finally: sys.argv[:] = saved @contextlib.contextmanager def save_path(): saved = sys.path[:] try: yield saved finally: sys.path[:] = saved @contextlib.contextmanager def override_temp(replacement): """ Monkey-patch tempfile.tempdir with replacement, ensuring it exists """ pkg_resources.py31compat.makedirs(replacement, exist_ok=True) saved = tempfile.tempdir tempfile.tempdir = replacement try: yield finally: tempfile.tempdir = saved @contextlib.contextmanager def pushd(target): saved = os.getcwd() os.chdir(target) try: yield saved finally: os.chdir(saved) class UnpickleableException(Exception): """ An exception representing another Exception that could not be pickled. """ @staticmethod def dump(type, exc): """ Always return a dumped (pickled) type and exc. If exc can't be pickled, wrap it in UnpickleableException first. """ try: return pickle.dumps(type), pickle.dumps(exc) except Exception: # get UnpickleableException inside the sandbox from setuptools.sandbox import UnpickleableException as cls return cls.dump(cls, cls(repr(exc))) class ExceptionSaver: """ A Context Manager that will save an exception, serialized, and restore it later. """ def __enter__(self): return self def __exit__(self, type, exc, tb): if not exc: return # dump the exception self._saved = UnpickleableException.dump(type, exc) self._tb = tb # suppress the exception return True def resume(self): "restore and re-raise any exception" if '_saved' not in vars(self): return type, exc = map(pickle.loads, self._saved) six.reraise(type, exc, self._tb) @contextlib.contextmanager def save_modules(): """ Context in which imported modules are saved. Translates exceptions internal to the context into the equivalent exception outside the context. """ saved = sys.modules.copy() with ExceptionSaver() as saved_exc: yield saved sys.modules.update(saved) # remove any modules imported since del_modules = ( mod_name for mod_name in sys.modules if mod_name not in saved # exclude any encodings modules. See #285 and not mod_name.startswith('encodings.') ) _clear_modules(del_modules) saved_exc.resume() def _clear_modules(module_names): for mod_name in list(module_names): del sys.modules[mod_name] @contextlib.contextmanager def save_pkg_resources_state(): saved = pkg_resources.__getstate__() try: yield saved finally: pkg_resources.__setstate__(saved) @contextlib.contextmanager def setup_context(setup_dir): temp_dir = os.path.join(setup_dir, 'temp') with save_pkg_resources_state(): with save_modules(): hide_setuptools() with save_path(): with save_argv(): with override_temp(temp_dir): with pushd(setup_dir): # ensure setuptools commands are available __import__('setuptools') yield def _needs_hiding(mod_name): """ >>> _needs_hiding('setuptools') True >>> _needs_hiding('pkg_resources') True >>> _needs_hiding('setuptools_plugin') False >>> _needs_hiding('setuptools.__init__') True >>> _needs_hiding('distutils') True >>> _needs_hiding('os') False >>> _needs_hiding('Cython') True """ pattern = re.compile(r'(setuptools|pkg_resources|distutils|Cython)(\.|$)') return bool(pattern.match(mod_name)) def hide_setuptools(): """ Remove references to setuptools' modules from sys.modules to allow the invocation to import the most appropriate setuptools. This technique is necessary to avoid issues such as #315 where setuptools upgrading itself would fail to find a function declared in the metadata. """ modules = filter(_needs_hiding, sys.modules) _clear_modules(modules) def run_setup(setup_script, args): """Run a distutils setup script, sandboxed in its directory""" setup_dir = os.path.abspath(os.path.dirname(setup_script)) with setup_context(setup_dir): try: sys.argv[:] = [setup_script] + list(args) sys.path.insert(0, setup_dir) # reset to include setup dir, w/clean callback list working_set.__init__() working_set.callbacks.append(lambda dist: dist.activate()) # __file__ should be a byte string on Python 2 (#712) dunder_file = ( setup_script if isinstance(setup_script, str) else setup_script.encode(sys.getfilesystemencoding()) ) with DirectorySandbox(setup_dir): ns = dict(__file__=dunder_file, __name__='__main__') _execfile(setup_script, ns) except SystemExit as v: if v.args and v.args[0]: raise # Normal exit, just return class AbstractSandbox: """Wrap 'os' module and 'open()' builtin for virtualizing setup scripts""" _active = False def __init__(self): self._attrs = [ name for name in dir(_os) if not name.startswith('_') and hasattr(self, name) ] def _copy(self, source): for name in self._attrs: setattr(os, name, getattr(source, name)) def __enter__(self): self._copy(self) if _file: builtins.file = self._file builtins.open = self._open self._active = True def __exit__(self, exc_type, exc_value, traceback): self._active = False if _file: builtins.file = _file builtins.open = _open self._copy(_os) def run(self, func): """Run 'func' under os sandboxing""" with self: return func() def _mk_dual_path_wrapper(name): original = getattr(_os, name) def wrap(self, src, dst, *args, **kw): if self._active: src, dst = self._remap_pair(name, src, dst, *args, **kw) return original(src, dst, *args, **kw) return wrap for name in ["rename", "link", "symlink"]: if hasattr(_os, name): locals()[name] = _mk_dual_path_wrapper(name) def _mk_single_path_wrapper(name, original=None): original = original or getattr(_os, name) def wrap(self, path, *args, **kw): if self._active: path = self._remap_input(name, path, *args, **kw) return original(path, *args, **kw) return wrap if _file: _file = _mk_single_path_wrapper('file', _file) _open = _mk_single_path_wrapper('open', _open) for name in [ "stat", "listdir", "chdir", "open", "chmod", "chown", "mkdir", "remove", "unlink", "rmdir", "utime", "lchown", "chroot", "lstat", "startfile", "mkfifo", "mknod", "pathconf", "access" ]: if hasattr(_os, name): locals()[name] = _mk_single_path_wrapper(name) def _mk_single_with_return(name): original = getattr(_os, name) def wrap(self, path, *args, **kw): if self._active: path = self._remap_input(name, path, *args, **kw) return self._remap_output(name, original(path, *args, **kw)) return original(path, *args, **kw) return wrap for name in ['readlink', 'tempnam']: if hasattr(_os, name): locals()[name] = _mk_single_with_return(name) def _mk_query(name): original = getattr(_os, name) def wrap(self, *args, **kw): retval = original(*args, **kw) if self._active: return self._remap_output(name, retval) return retval return wrap for name in ['getcwd', 'tmpnam']: if hasattr(_os, name): locals()[name] = _mk_query(name) def _validate_path(self, path): """Called to remap or validate any path, whether input or output""" return path def _remap_input(self, operation, path, *args, **kw): """Called for path inputs""" return self._validate_path(path) def _remap_output(self, operation, path): """Called for path outputs""" return self._validate_path(path) def _remap_pair(self, operation, src, dst, *args, **kw): """Called for path pairs like rename, link, and symlink operations""" return ( self._remap_input(operation + '-from', src, *args, **kw), self._remap_input(operation + '-to', dst, *args, **kw) ) if hasattr(os, 'devnull'): _EXCEPTIONS = [os.devnull,] else: _EXCEPTIONS = [] class DirectorySandbox(AbstractSandbox): """Restrict operations to a single subdirectory - pseudo-chroot""" write_ops = dict.fromkeys([ "open", "chmod", "chown", "mkdir", "remove", "unlink", "rmdir", "utime", "lchown", "chroot", "mkfifo", "mknod", "tempnam", ]) _exception_patterns = [ # Allow lib2to3 to attempt to save a pickled grammar object (#121) r'.*lib2to3.*\.pickle$', ] "exempt writing to paths that match the pattern" def __init__(self, sandbox, exceptions=_EXCEPTIONS): self._sandbox = os.path.normcase(os.path.realpath(sandbox)) self._prefix = os.path.join(self._sandbox, '') self._exceptions = [ os.path.normcase(os.path.realpath(path)) for path in exceptions ] AbstractSandbox.__init__(self) def _violation(self, operation, *args, **kw): from setuptools.sandbox import SandboxViolation raise SandboxViolation(operation, args, kw) if _file: def _file(self, path, mode='r', *args, **kw): if mode not in ('r', 'rt', 'rb', 'rU', 'U') and not self._ok(path): self._violation("file", path, mode, *args, **kw) return _file(path, mode, *args, **kw) def _open(self, path, mode='r', *args, **kw): if mode not in ('r', 'rt', 'rb', 'rU', 'U') and not self._ok(path): self._violation("open", path, mode, *args, **kw) return _open(path, mode, *args, **kw) def tmpnam(self): self._violation("tmpnam") def _ok(self, path): active = self._active try: self._active = False realpath = os.path.normcase(os.path.realpath(path)) return ( self._exempted(realpath) or realpath == self._sandbox or realpath.startswith(self._prefix) ) finally: self._active = active def _exempted(self, filepath): start_matches = ( filepath.startswith(exception) for exception in self._exceptions ) pattern_matches = ( re.match(pattern, filepath) for pattern in self._exception_patterns ) candidates = itertools.chain(start_matches, pattern_matches) return any(candidates) def _remap_input(self, operation, path, *args, **kw): """Called for path inputs""" if operation in self.write_ops and not self._ok(path): self._violation(operation, os.path.realpath(path), *args, **kw) return path def _remap_pair(self, operation, src, dst, *args, **kw): """Called for path pairs like rename, link, and symlink operations""" if not self._ok(src) or not self._ok(dst): self._violation(operation, src, dst, *args, **kw) return (src, dst) def open(self, file, flags, mode=0o777, *args, **kw): """Called for low-level os.open()""" if flags & WRITE_FLAGS and not self._ok(file): self._violation("os.open", file, flags, mode, *args, **kw) return _os.open(file, flags, mode, *args, **kw) WRITE_FLAGS = functools.reduce( operator.or_, [getattr(_os, a, 0) for a in "O_WRONLY O_RDWR O_APPEND O_CREAT O_TRUNC O_TEMPORARY".split()] ) class SandboxViolation(DistutilsError): """A setup script attempted to modify the filesystem outside the sandbox""" tmpl = textwrap.dedent(""" SandboxViolation: {cmd}{args!r} {kwargs} The package setup script has attempted to modify files on your system that are not within the EasyInstall build area, and has been aborted. This package cannot be safely installed by EasyInstall, and may not support alternate installation locations even if you run its setup script by hand. Please inform the package's author and the EasyInstall maintainers to find out if a fix or workaround is available. """).lstrip() def __str__(self): cmd, args, kwargs = self.args return self.tmpl.format(**locals())
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