63 lines
2.3 KiB
Python
63 lines
2.3 KiB
Python
|
import os
|
||
|
|
import tempfile
|
||
|
|
from os.path import abspath, dirname, join, normcase, sep
|
||
|
|
from pathlib import Path
|
||
|
|
|
||
|
|
from django.core.exceptions import SuspiciousFileOperation
|
||
|
|
|
||
|
|
|
||
|
|
def safe_join(base, *paths):
|
||
|
|
"""
|
||
|
|
Join one or more path components to the base path component intelligently.
|
||
|
|
Return a normalized, absolute version of the final path.
|
||
|
|
|
||
|
|
Raise ValueError if the final path isn't located inside of the base path
|
||
|
|
component.
|
||
|
|
"""
|
||
|
|
final_path = abspath(join(base, *paths))
|
||
|
|
base_path = abspath(base)
|
||
|
|
# Ensure final_path starts with base_path (using normcase to ensure we
|
||
|
|
# don't false-negative on case insensitive operating systems like Windows),
|
||
|
|
# further, one of the following conditions must be true:
|
||
|
|
# a) The next character is the path separator (to prevent conditions like
|
||
|
|
# safe_join("/dir", "/../d"))
|
||
|
|
# b) The final path must be the same as the base path.
|
||
|
|
# c) The base path must be the most root path (meaning either "/" or "C:\\")
|
||
|
|
if (
|
||
|
|
not normcase(final_path).startswith(normcase(base_path + sep))
|
||
|
|
and normcase(final_path) != normcase(base_path)
|
||
|
|
and dirname(normcase(base_path)) != normcase(base_path)
|
||
|
|
):
|
||
|
|
raise SuspiciousFileOperation(
|
||
|
|
"The joined path ({}) is located outside of the base path "
|
||
|
|
"component ({})".format(final_path, base_path)
|
||
|
|
)
|
||
|
|
return final_path
|
||
|
|
|
||
|
|
|
||
|
|
def symlinks_supported():
|
||
|
|
"""
|
||
|
|
Return whether or not creating symlinks are supported in the host platform
|
||
|
|
and/or if they are allowed to be created (e.g. on Windows it requires admin
|
||
|
|
permissions).
|
||
|
|
"""
|
||
|
|
with tempfile.TemporaryDirectory() as temp_dir:
|
||
|
|
original_path = os.path.join(temp_dir, "original")
|
||
|
|
symlink_path = os.path.join(temp_dir, "symlink")
|
||
|
|
os.makedirs(original_path)
|
||
|
|
try:
|
||
|
|
os.symlink(original_path, symlink_path)
|
||
|
|
supported = True
|
||
|
|
except (OSError, NotImplementedError):
|
||
|
|
supported = False
|
||
|
|
return supported
|
||
|
|
|
||
|
|
|
||
|
|
def to_path(value):
|
||
|
|
"""Convert value to a pathlib.Path instance, if not already a Path."""
|
||
|
|
if isinstance(value, Path):
|
||
|
|
return value
|
||
|
|
elif not isinstance(value, str):
|
||
|
|
raise TypeError("Invalid path type: %s" % type(value).__name__)
|
||
|
|
return Path(value)
|