import os
import sys
[docs]class SoftChrootInitError(IOError):
"""Error during soft-chroot initialization"""
pass
[docs]class SoftChroot:
"""Soft Chroot module
Provides chroot feature for interation with Web-UI. Since it is not real chroot, so the name is SOFT CHROOT.
The module prevents access to entire file-system, allowing access only to subdirs of SOFT-CHROOT directory.
"""
def __init__(self):
self.enabled = None
self.chdir = None
[docs] def initialize(self, chdir):
""" initialize module, by setting soft-chroot-directory
Sets soft-chroot directory and 'enabled'-flag
Args:
self (SoftChroot) : self
chdir (string) : absolute path to soft-chroot
Raises:
SoftChrootInitError: when chdir doesn't exist
"""
orig_chdir = chdir
if chdir:
chdir = chdir.strip()
if (chdir):
# enabling soft-chroot:
if not os.path.isdir(chdir):
raise SoftChrootInitError(2, 'SOFT-CHROOT is requested, but the folder doesn\'t exist', orig_chdir)
self.enabled = True
self.chdir = chdir.rstrip(os.path.sep) + os.path.sep
else:
self.enabled = False
[docs] def get_chroot(self):
"""Returns root in chrooted environment
Raises:
RuntimeError: when `SoftChroot` is not initialized OR enabled
"""
if None == self.enabled:
raise RuntimeError('SoftChroot is not initialized')
if not self.enabled:
raise RuntimeError('SoftChroot is not enabled')
return self.chdir
[docs] def is_root_abs(self, abspath):
""" Checks whether absolute path @abspath is the root in the soft-chrooted environment"""
if None == self.enabled:
raise RuntimeError('SoftChroot is not initialized')
if None == abspath:
raise ValueError('abspath can not be None')
if not self.enabled:
# if not chroot environment : check, whether parent is the same dir:
parent = os.path.dirname(abspath.rstrip(os.path.sep))
return parent==abspath
# in soft-chrooted env: check, that path == chroot
path = abspath.rstrip(os.path.sep) + os.path.sep
return self.chdir == path
[docs] def is_subdir(self, abspath):
""" Checks whether @abspath is subdir (on any level) of soft-chroot"""
if None == self.enabled:
raise RuntimeError('SoftChroot is not initialized')
if None == abspath:
return False
if not self.enabled:
return True
if not abspath.endswith(os.path.sep):
abspath += os.path.sep
return abspath.startswith(self.chdir)
[docs] def chroot2abs(self, path):
""" Converts chrooted path to absolute path"""
if None == self.enabled:
raise RuntimeError('SoftChroot is not initialized')
if not self.enabled:
return path
if None == path or len(path)==0:
return self.chdir
if not path.startswith(os.path.sep):
path = os.path.sep + path
return self.chdir[:-1] + path
[docs] def abs2chroot(self, path, force = False):
""" Converts absolute path to chrooted path"""
if None == self.enabled:
raise RuntimeError('SoftChroot is not initialized')
if None == path:
raise ValueError('path is empty')
if not self.enabled:
return path
if path == self.chdir.rstrip(os.path.sep):
return '/'
resulst = None
if not path.startswith(self.chdir):
if (force):
result = self.get_chroot()
else:
raise ValueError("path must starts with 'chdir': %s" % path)
else:
l = len(self.chdir)-1
result = path[l:]
return result