JezK
Edit File: unpacking.py
"""Utilities related archives. """ import logging import os import shutil import stat import tarfile import zipfile from typing import Iterable, List, Optional from zipfile import ZipInfo from pip._internal.exceptions import InstallationError from pip._internal.utils.filetypes import ( BZ2_EXTENSIONS, TAR_EXTENSIONS, XZ_EXTENSIONS, ZIP_EXTENSIONS, ) from pip._internal.utils.misc import ensure_dir logger = logging.getLogger(__name__) SUPPORTED_EXTENSIONS = ZIP_EXTENSIONS + TAR_EXTENSIONS try: import bz2 # noqa SUPPORTED_EXTENSIONS += BZ2_EXTENSIONS except ImportError: logger.debug("bz2 module is not available") try: # Only for Python 3.3+ import lzma # noqa SUPPORTED_EXTENSIONS += XZ_EXTENSIONS except ImportError: logger.debug("lzma module is not available") def current_umask() -> int: """Get the current umask which involves having to set it temporarily.""" mask = os.umask(0) os.umask(mask) return mask def split_leading_dir(path: str) -> List[str]: path = path.lstrip("/").lstrip("\\") if "/" in path and ( ("\\" in path and path.find("/") < path.find("\\")) or "\\" not in path ): return path.split("/", 1) elif "\\" in path: return path.split("\\", 1) else: return [path, ""] def has_leading_dir(paths: Iterable[str]) -> bool: """Returns true if all the paths have the same leading path name (i.e., everything is in one subdirectory in an archive)""" common_prefix = None for path in paths: prefix, rest = split_leading_dir(path) if not prefix: return False elif common_prefix is None: common_prefix = prefix elif prefix != common_prefix: return False return True def is_within_directory(directory: str, target: str) -> bool: """ Return true if the absolute path of target is within the directory """ abs_directory = os.path.abspath(directory) abs_target = os.path.abspath(target) prefix = os.path.commonprefix([abs_directory, abs_target]) return prefix == abs_directory def set_extracted_file_to_default_mode_plus_executable(path: str) -> None: """ Make file present at path have execute for user/group/world (chmod +x) is no-op on windows per python docs """ os.chmod(path, (0o777 & ~current_umask() | 0o111)) def zip_item_is_executable(info: ZipInfo) -> bool: mode = info.external_attr >> 16 # if mode and regular file and any execute permissions for # user/group/world? return bool(mode and stat.S_ISREG(mode) and mode & 0o111) def unzip_file(filename: str, location: str, flatten: bool = True) -> None: """ Unzip the file (with path `filename`) to the destination `location`. All files are written based on system defaults and umask (i.e. permissions are not preserved), except that regular file members with any execute permissions (user, group, or world) have "chmod +x" applied after being written. Note that for windows, any execute changes using os.chmod are no-ops per the python docs. """ ensure_dir(location) zipfp = open(filename, "rb") try: zip = zipfile.ZipFile(zipfp, allowZip64=True) leading = has_leading_dir(zip.namelist()) and flatten for info in zip.infolist(): name = info.filename fn = name if leading: fn = split_leading_dir(name)[1] fn = os.path.join(location, fn) dir = os.path.dirname(fn) if not is_within_directory(location, fn): message = ( "The zip file ({}) has a file ({}) trying to install " "outside target directory ({})" ) raise InstallationError(message.format(filename, fn, location)) if fn.endswith("/") or fn.endswith("\\"): # A directory ensure_dir(fn) else: ensure_dir(dir) # Don't use read() to avoid allocating an arbitrarily large # chunk of memory for the file's content fp = zip.open(name) try: with open(fn, "wb") as destfp: shutil.copyfileobj(fp, destfp) finally: fp.close() if zip_item_is_executable(info): set_extracted_file_to_default_mode_plus_executable(fn) finally: zipfp.close() def untar_file(filename: str, location: str) -> None: """ Untar the file (with path `filename`) to the destination `location`. All files are written based on system defaults and umask (i.e. permissions are not preserved), except that regular file members with any execute permissions (user, group, or world) have "chmod +x" applied after being written. Note that for windows, any execute changes using os.chmod are no-ops per the python docs. """ ensure_dir(location) if filename.lower().endswith(".gz") or filename.lower().endswith(".tgz"): mode = "r:gz" elif filename.lower().endswith(BZ2_EXTENSIONS): mode = "r:bz2" elif filename.lower().endswith(XZ_EXTENSIONS): mode = "r:xz" elif filename.lower().endswith(".tar"): mode = "r" else: logger.warning( "Cannot determine compression type for file %s", filename, ) mode = "r:*" tar = tarfile.open(filename, mode, encoding="utf-8") try: leading = has_leading_dir([member.name for member in tar.getmembers()]) for member in tar.getmembers(): fn = member.name if leading: fn = split_leading_dir(fn)[1] path = os.path.join(location, fn) if not is_within_directory(location, path): message = ( "The tar file ({}) has a file ({}) trying to install " "outside target directory ({})" ) raise InstallationError(message.format(filename, path, location)) if member.isdir(): ensure_dir(path) elif member.issym(): try: tar._extract_member(member, path) except Exception as exc: # Some corrupt tar files seem to produce this # (specifically bad symlinks) logger.warning( "In the tar file %s the member %s is invalid: %s", filename, member.name, exc, ) continue else: try: fp = tar.extractfile(member) except (KeyError, AttributeError) as exc: # Some corrupt tar files seem to produce this # (specifically bad symlinks) logger.warning( "In the tar file %s the member %s is invalid: %s", filename, member.name, exc, ) continue ensure_dir(os.path.dirname(path)) assert fp is not None with open(path, "wb") as destfp: shutil.copyfileobj(fp, destfp) fp.close() # Update the timestamp (useful for cython compiled files) tar.utime(member, path) # member have any execute permissions for user/group/world? if member.mode & 0o111: set_extracted_file_to_default_mode_plus_executable(path) finally: tar.close() def unpack_file( filename: str, location: str, content_type: Optional[str] = None, ) -> None: filename = os.path.realpath(filename) if ( content_type == "application/zip" or filename.lower().endswith(ZIP_EXTENSIONS) or zipfile.is_zipfile(filename) ): unzip_file(filename, location, flatten=not filename.endswith(".whl")) elif ( content_type == "application/x-gzip" or tarfile.is_tarfile(filename) or filename.lower().endswith(TAR_EXTENSIONS + BZ2_EXTENSIONS + XZ_EXTENSIONS) ): untar_file(filename, location) else: # FIXME: handle? # FIXME: magic signatures? logger.critical( "Cannot unpack file %s (downloaded from %s, content-type: %s); " "cannot detect archive format", filename, location, content_type, ) raise InstallationError(f"Cannot determine archive format of {location}")