"""General SFTP storage. Subclass it the way you want!"""
import os
import itertools
from pysftpserver.abstractstorage import SFTPAbstractServerStorage
from pysftpserver.futimes import futimes
from pysftpserver.stat_helpers import stat_to_longname
class SFTPServerStorage(SFTPAbstractServerStorage):
"""Simple storage class. Subclass it and override the methods."""
def __init__(self, home, umask=None):
"""Home sweet home.
Set your home to something comfortable and chdir to it.
You should support umask changing too.
"""
self.home = os.path.realpath(home)
os.chdir(self.home)
if umask:
os.umask(umask)
def verify(self, filename):
"""Verify that requested filename is accessible.
In this simple storage class this is always True
(and thus possibly insecure).
"""
return True
def stat(self, filename, lstat=False, fstat=False, parent=None):
"""stat, lstat and fstat requests.
Return a dictionary of stats.
Filename is an handle in the fstat variant.
If parent is not None, then filename is inside parent,
and a join is needed.
This happens in case of readdir responses:
a filename (not a path) has to be returned,
but the stat call need (obviously) a full path.
"""
if not lstat and fstat:
# filename is an handle
_stat = os.fstat(filename)
elif lstat:
_stat = os.lstat(filename)
else:
try:
_stat = os.stat(
filename if not parent
else os.path.join(parent, filename)
)
except:
# we could have a broken symlink
# but lstat could be false:
# this happens in case of readdir responses
_stat = os.lstat(
filename if not parent
else os.path.join(parent, filename)
)
if fstat:
longname = None # not needed in case of fstat
else:
longname = stat_to_longname( # see stat_helpers.py
_stat, filename
)
return {
b'size': _stat.st_size,
b'uid': _stat.st_uid,
b'gid': _stat.st_gid,
b'perm': _stat.st_mode,
b'atime': _stat.st_atime,
b'mtime': _stat.st_mtime,
b'longname': longname
}
def setstat(self, filename, attrs, fsetstat=False):
"""setstat and fsetstat requests.
Filename is an handle in the fstat variant.
If you're using Python < 3.3,
you could find useful the futimes file / function.
"""
if not fsetstat:
f = os.open(filename, os.O_WRONLY)
chown = os.chown
chmod = os.chmod
else: # filename is a fd
f = filename
chown = os.fchown
chmod = os.fchmod
if b'size' in attrs:
os.ftruncate(f, attrs[b'size'])
if all(k in attrs for k in (b'uid', b'gid')):
chown(filename, attrs[b'uid'], attrs[b'gid'])
if b'perm' in attrs:
chmod(filename, attrs[b'perm'])
if all(k in attrs for k in (b'atime', b'mtime')):
if not fsetstat:
os.utime(filename, (attrs[b'atime'], attrs[b'mtime']))
else:
futimes(filename, (attrs[b'atime'], attrs[b'mtime']))
def opendir(self, filename):
"""Return an iterator over the files in filename."""
return itertools.chain(iter([b'.', b'..']), iter(os.listdir(filename)))
def open(self, filename, flags, mode):
"""Return the file handle."""
return os.open(filename, flags, mode)
def mkdir(self, filename, mode):
"""Create directory with given mode."""
os.mkdir(filename, mode)
def rmdir(self, filename):
"""Remove directory."""
os.rmdir(filename)
def rm(self, filename):
"""Remove file."""
os.remove(filename)
def rename(self, oldpath, newpath):
"""Move/rename file."""
os.rename(oldpath, newpath)
def symlink(self, linkpath, targetpath):
"""Symlink file."""
os.symlink(targetpath, linkpath)
def readlink(self, filename):
"""Readlink of filename."""
return os.readlink(filename)
def write(self, handle, off, chunk):
"""Write chunk at offset of handle."""
os.lseek(handle, off, os.SEEK_SET)
rlen = os.write(handle, chunk)
if rlen == len(chunk):
return True
def read(self, handle, off, size):
"""Read from the handle size, starting from offset off."""
os.lseek(handle, off, os.SEEK_SET)
return os.read(handle, size)
def close(self, handle):
"""Close the file handle."""
try:
handle.close()
except AttributeError:
pass
