import os
import pathlib
from django.core.exceptions import SuspiciousFileOperation
def validate_file_name(name, allow_relative_path=False):
# Remove potentially dangerous names
if os.path.basename(name) in {'', '.', '..'}:
raise SuspiciousFileOperation("Could not derive file name from '%s'" % name)
if allow_relative_path:
# Use PurePosixPath() because this branch is checked only in
# FileField.generate_filename() where all file paths are expected to be
# Unix style (with forward slashes).
path = pathlib.PurePosixPath(name)
if path.is_absolute() or '..' in path.parts:
raise SuspiciousFileOperation(
"Detected path traversal attempt in '%s'" % name
)
elif name != os.path.basename(name):
raise SuspiciousFileOperation("File name '%s' includes path elements" % name)
return name
class FileProxyMixin:
"""
A mixin class used to forward file methods to an underlaying file
object. The internal file object has to be called "file"::
class FileProxy(FileProxyMixin):
def __init__(self, file):
self.file = file
"""
encoding = property(lambda self: self.file.encoding)
fileno = property(lambda self: self.file.fileno)
flush = property(lambda self: self.file.flush)
isatty = property(lambda self: self.file.isatty)
newlines = property(lambda self: self.file.newlines)
read = property(lambda self: self.file.read)
readinto = property(lambda self: self.file.readinto)
readline = property(lambda self: self.file.readline)
readlines = property(lambda self: self.file.readlines)
seek = property(lambda self: self.file.seek)
tell = property(lambda self: self.file.tell)
truncate = property(lambda self: self.file.truncate)
write = property(lambda self: self.file.write)
writelines = property(lambda self: self.file.writelines)
@property
def closed(self):
return not self.file or self.file.closed
def readable(self):
if self.closed:
return False
if hasattr(self.file, 'readable'):
return self.file.readable()
return True
def writable(self):
if self.closed:
return False
if hasattr(self.file, 'writable'):
return self.file.writable()
return 'w' in getattr(self.file, 'mode', '')
def seekable(self):
if self.closed:
return False
if hasattr(self.file, 'seekable'):
return self.file.seekable()
return True
def __iter__(self):
return iter(self.file)