# Copyright (C) 2003-2007 Robey Pointer <robeypointer@gmail.com>
#
# This file is part of paramiko.
#
# Paramiko is free software; you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation; either version 2.1 of the License, or (at your option)
# any later version.
#
# Paramiko is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
"""
Client-mode SFTP support.
"""
from binascii import hexlify
import errno
import os
import stat
import threading
import time
import weakref
from paramiko.sftp import *
from paramiko.sftp_attr import SFTPAttributes
from paramiko.ssh_exception import SSHException
from paramiko.sftp_file import SFTPFile
def _to_unicode(s):
"""
decode a string as ascii or utf8 if possible (as required by the sftp
protocol). if neither works, just return a byte string because the server
probably doesn't know the filename's encoding.
"""
try:
return s.encode('ascii')
except UnicodeError:
try:
return s.decode('utf-8')
except UnicodeError:
return s
class SFTPClient (BaseSFTP):
"""
SFTP client object. C{SFTPClient} is used to open an sftp session across
an open ssh L{Transport} and do remote file operations.
"""
def __init__(self, sock):
"""
Create an SFTP client from an existing L{Channel}. The channel
should already have requested the C{"sftp"} subsystem.
An alternate way to create an SFTP client context is by using
L{from_transport}.
@param sock: an open L{Channel} using the C{"sftp"} subsystem
@type sock: L{Channel}
@raise SSHException: if there's an exception while negotiating
sftp
"""
BaseSFTP.__init__(self)
self.sock = sock
self.ultra_debug = False
self.request_number = 1
# lock for request_number
self._lock = threading.Lock()
self._cwd = None
# request # -> SFTPFile
self._expecting = weakref.WeakValueDictionary()
if type(sock) is Channel:
# override default logger
transport = self.sock.get_transport()
self.logger = util.get_logger(transport.get_log_channel() + '.sftp')
self.ultra_debug = transport.get_hexdump()
try:
server_version = self._send_version()
except EOFError, x:
raise SSHException('EOF during negotiation')
self._log(INFO, 'Opened sftp connection (server version %d)' % server_version)
def from_transport(cls, t):
"""
Create an SFTP client channel from an open L{Transport}.
@param t: an open L{Transport} which is already authenticated
@type t: L{Transport}
@return: a new L{SFTPClient} object, referring to an sftp session
(channel) across the transport
@rtype: L{SFTPClient}
"""
chan = t.open_session()
if chan is None:
return None
chan.invoke_subsystem('sftp')
return cls(chan)
from_transport = classmethod(from_transport)
def _log(self, level, msg, *args):
if isinstance(msg, list):
for m in msg:
super(SFTPClient, self)._log(level, "[chan %s] " + m, *([ self.sock.get_name() ] + list(args)))
else:
super(SFTPClient, self)._log(level, "[chan %s] " + msg, *([ self.sock.get_name() ] + list(args)))
def close(self):
"""
Close the SFTP session and its underlying channel.
@since: 1.4
"""
self._log(INFO, 'sftp session closed.')
self.sock.close()
def get_channel(self):
"""
Return the underlying L{Channel} object for this SFTP session. This
might be useful for doing things like setting a timeout on the channel.
@return: the SSH channel
@rtype: L{Channel}
@since: 1.7.1
"""
return self.sock
def listdir(self, path='.'):
"""
Return a list containing the names of the entries in the given C{path}.
The list is in arbitrary order. It does not include the special
entries C{'.'} and C{'..'} even if they are present in the folder.
This method is meant to mirror C{os.listdir} as closely as possible.
For a list of full L{SFTPAttributes} objects, see L{listdir_attr}.
@param path: path to list (defaults to C{'.'})
@type path: str
@return: list of filenames
@rtype: list of str
"""
return [f.filename for f in self.listdir_attr(path)]
def listdir_attr(self, path='.'):
"""
Return a list containing L{SFTPAttributes} objects corresponding to
files in the given C{path}. The list is in arbitrary order. It does
not include the special entries C{'.'} and C{'..'} even if they are
present in the folder.
The returned L{SFTPAttributes} objects will each have an additional
field: C{longname}, which may contain a formatted string of the file's
attributes, in unix format. The content of this string will probably
depend on the SFTP server implementation.
@param path: path to list (defaults to C{'.'})
@type path: str
@return: list of attributes
@rtype: list of L{SFTPAttributes}
@since: 1.2
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'listdir(%r)' % path)
t, msg = self._request(CMD_OPENDIR, path)
if t != CMD_HANDLE:
raise SFTPError('Expected handle')
handle = msg.get_string()
filelist = []
while True:
try:
t, msg = self._request(CMD_READDIR, handle)
except EOFError, e:
# done with handle
break
if t != CMD_NAME:
raise SFTPError('Expected name response')
count = msg.get_int()
for i in range(count):
filename = _to_unicode(msg.get_string())
longname = _to_unicode(msg.get_string())
attr = SFTPAttributes._from_msg(msg, filename, longname)
if (filename != '.') and (filename != '..'):
filelist.append(attr)
self._request(CMD_CLOSE, handle)
return filelist
def open(self, filename, mode='r', bufsize=-1):
"""
Open a file on the remote server. The arguments are the same as for
python's built-in C{file} (aka C{open}). A file-like object is
returned, which closely mimics the behavior of a normal python file
object, including the ability to be used as a context manager.
The mode indicates how the file is to be opened: C{'r'} for reading,
C{'w'} for writing (truncating an existing file), C{'a'} for appending,
C{'r+'} for reading/writing, C{'w+'} for reading/writing (truncating an
existing file), C{'a+'} for reading/appending. The python C{'b'} flag
is ignored, since SSH treats all files as binary. The C{'U'} flag is
supported in a compatible way.
Since 1.5.2, an C{'x'} flag indicates that the operation should only
succeed if the file was created and did not previously exist. This has
no direct mapping to python's file flags, but is commonly known as the
C{O_EXCL} flag in posix.
The file will be buffered in standard python style by default, but
can be altered with the C{bufsize} parameter. C{0} turns off
buffering, C{1} uses line buffering, and any number greater than 1
(C{>1}) uses that specific buffer size.
@param filename: name of the file to open
@type filename: str
@param mode: mode (python-style) to open in
@type mode: str
@param bufsize: desired buffering (-1 = default buffer size)
@type bufsize: int
@return: a file object representing the open file
@rtype: SFTPFile
@raise IOError: if the file could not be opened.
"""
filename = self._adjust_cwd(filename)
self._log(DEBUG, 'open(%r, %r)' % (filename, mode))
imode = 0
if ('r' in mode) or ('+' in mode):
imode |= SFTP_FLAG_READ
if ('w' in mode) or ('+' in mode) or ('a' in mode):
imode |= SFTP_FLAG_WRITE
if ('w' in mode):
imode |= SFTP_FLAG_CREATE | SFTP_FLAG_TRUNC
if ('a' in mode):
imode |= SFTP_FLAG_CREATE | SFTP_FLAG_APPEND
if ('x' in mode):
imode |= SFTP_FLAG_CREATE | SFTP_FLAG_EXCL
attrblock = SFTPAttributes()
t, msg = self._request(CMD_OPEN, filename, imode, attrblock)
if t != CMD_HANDLE:
raise SFTPError('Expected handle')
handle = msg.get_string()
self._log(DEBUG, 'open(%r, %r) -> %s' % (filename, mode, hexlify(handle)))
return SFTPFile(self, handle, mode, bufsize)
# python continues to vacillate about "open" vs "file"...
file = open
def remove(self, path):
"""
Remove the file at the given path. This only works on files; for
removing folders (directories), use L{rmdir}.
@param path: path (absolute or relative) of the file to remove
@type path: str
@raise IOError: if the path refers to a folder (directory)
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'remove(%r)' % path)
self._request(CMD_REMOVE, path)
unlink = remove
def rename(self, oldpath, newpath):
"""
Rename a file or folder from C{oldpath} to C{newpath}.
@param oldpath: existing name of the file or folder
@type oldpath: str
@param newpath: new name for the file or folder
@type newpath: str
@raise IOError: if C{newpath} is a folder, or something else goes
wrong
"""
oldpath = self._adjust_cwd(oldpath)
newpath = self._adjust_cwd(newpath)
self._log(DEBUG, 'rename(%r, %r)' % (oldpath, newpath))
self._request(CMD_RENAME, oldpath, newpath)
def mkdir(self, path, mode=0777):
"""
Create a folder (directory) named C{path} with numeric mode C{mode}.
The default mode is 0777 (octal). On some systems, mode is ignored.
Where it is used, the current umask value is first masked out.
@param path: name of the folder to create
@type path: str
@param mode: permissions (posix-style) for the newly-created folder
@type mode: int
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'mkdir(%r, %r)' % (path, mode))
attr = SFTPAttributes()
attr.st_mode = mode
self._request(CMD_MKDIR, path, attr)
def rmdir(self, path):
"""
Remove the folder named C{path}.
@param path: name of the folder to remove
@type path: str
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'rmdir(%r)' % path)
self._request(CMD_RMDIR, path)
def stat(self, path):
"""
Retrieve information about a file on the remote system. The return
value is an object whose attributes correspond to the attributes of
python's C{stat} structure as returned by C{os.stat}, except that it
contains fewer fields. An SFTP server may return as much or as little
info as it wants, so the results may vary from server to server.
Unlike a python C{stat} object, the result may not be accessed as a
tuple. This is mostly due to the author's slack factor.
The fields supported are: C{st_mode}, C{st_size}, C{st_uid}, C{st_gid},
C{st_atime}, and C{st_mtime}.
@param path: the filename to stat
@type path: str
@return: an object containing attributes about the given file
@rtype: SFTPAttributes
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'stat(%r)' % path)
t, msg = self._request(CMD_STAT, path)
if t != CMD_ATTRS:
raise SFTPError('Expected attributes')
return SFTPAttributes._from_msg(msg)
def lstat(self, path):
"""
Retrieve information about a file on the remote system, without
following symbolic links (shortcuts). This otherwise behaves exactly
the same as L{stat}.
@param path: the filename to stat
@type path: str
@return: an object containing attributes about the given file
@rtype: SFTPAttributes
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'lstat(%r)' % path)
t, msg = self._request(CMD_LSTAT, path)
if t != CMD_ATTRS:
raise SFTPError('Expected attributes')
return SFTPAttributes._from_msg(msg)
def symlink(self, source, dest):
"""
Create a symbolic link (shortcut) of the C{source} path at
C{destination}.
@param source: path of the original file
@type source: str
@param dest: path of the newly created symlink
@type dest: str
"""
dest = self._adjust_cwd(dest)
self._log(DEBUG, 'symlink(%r, %r)' % (source, dest))
if type(source) is unicode:
source = source.encode('utf-8')
self._request(CMD_SYMLINK, source, dest)
def chmod(self, path, mode):
"""
Change the mode (permissions) of a file. The permissions are
unix-style and identical to those used by python's C{os.chmod}
function.
@param path: path of the file to change the permissions of
@type path: str
@param mode: new permissions
@type mode: int
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'chmod(%r, %r)' % (path, mode))
attr = SFTPAttributes()
attr.st_mode = mode
self._request(CMD_SETSTAT, path, attr)
def chown(self, path, uid, gid):
"""
Change the owner (C{uid}) and group (C{gid}) of a file. As with
python's C{os.chown} function, you must pass both arguments, so if you
only want to change one, use L{stat} first to retrieve the current
owner and group.
@param path: path of the file to change the owner and group of
@type path: str
@param uid: new owner's uid
@type uid: int
@param gid: new group id
@type gid: int
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'chown(%r, %r, %r)' % (path, uid, gid))
attr = SFTPAttributes()
attr.st_uid, attr.st_gid = uid, gid
self._request(CMD_SETSTAT, path, attr)
def utime(self, path, times):
"""
Set the access and modified times of the file specified by C{path}. If
C{times} is C{None}, then the file's access and modified times are set
to the current time. Otherwise, C{times} must be a 2-tuple of numbers,
of the form C{(atime, mtime)}, which is used to set the access and
modified times, respectively. This bizarre API is mimicked from python
for the sake of consistency -- I apologize.
@param path: path of the file to modify
@type path: str
@param times: C{None} or a tuple of (access time, modified time) in
standard internet epoch time (seconds since 01 January 1970 GMT)
@type times: tuple(int)
"""
path = self._adjust_cwd(path)
if times is None:
times = (time.time(), time.time())
self._log(DEBUG, 'utime(%r, %r)' % (path, times))
attr = SFTPAttributes()
attr.st_atime, attr.st_mtime = times
self._request(CMD_SETSTAT, path, attr)
def truncate(self, path, size):
"""
Change the size of the file specified by C{path}. This usually extends
or shrinks the size of the file, just like the C{truncate()} method on
python file objects.
@param path: path of the file to modify
@type path: str
@param size: the new size of the file
@type size: int or long
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'truncate(%r, %r)' % (path, size))
attr = SFTPAttributes()
attr.st_size = size
self._request(CMD_SETSTAT, path, attr)
def readlink(self, path):
"""
Return the target of a symbolic link (shortcut). You can use
L{symlink} to create these. The result may be either an absolute or
relative pathname.
@param path: path of the symbolic link file
@type path: str
@return: target path
@rtype: str
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'readlink(%r)' % path)
t, msg = self._request(CMD_READLINK, path)
if t != CMD_NAME:
raise SFTPError('Expected name response')
count = msg.get_int()
if count == 0:
return None
if count != 1:
raise SFTPError('Readlink returned %d results' % count)
return _to_unicode(msg.get_string())
def normalize(self, path):
"""
Return the normalized path (on the server) of a given path. This
can be used to quickly resolve symbolic links or determine what the
server is considering to be the "current folder" (by passing C{'.'}
as C{path}).
@param path: path to be normalized
@type path: str
@return: normalized form of the given path
@rtype: str
@raise IOError: if the path can't be resolved on the server
"""
path = self._adjust_cwd(path)
self._log(DEBUG, 'normalize(%r)' % path)
t, msg = self._request(CMD_REALPATH, path)
if t != CMD_NAME:
raise SFTPError('Expected name response')
count = msg.get_int()
if count != 1:
raise SFTPError('Realpath returned %d results' % count)
return _to_unicode(msg.get_string())
def chdir(self, path):
"""
Change the "current directory" of this SFTP session. Since SFTP
doesn't really have the concept of a current working directory, this
is emulated by paramiko. Once you use this method to set a working
directory, all operations on this SFTPClient object will be relative
to that path. You can pass in C{None} to stop using a current working
directory.
@param path: new current working directory
@type path: str
@raise IOError: if the requested path doesn't exist on the server
@since: 1.4
"""
if path is None:
self._cwd = None
return
if not stat.S_ISDIR(self.stat(path).st_mode):
raise SFTPError(errno.ENOTDIR, "%s: %s" % (os.strerror(errno.ENOTDIR), path))
self._cwd = self.normalize(path).encode('utf-8')
def getcwd(self):
"""
Return the "current working directory" for this SFTP session, as
emulated by paramiko. If no directory has been set with L{chdir},
this method will return C{None}.
@return: the current working directory on the server, or C{None}
@rtype: str
@since: 1.4
"""
return self._cwd
def putfo(self, fl, remotepath, file_size=0, callback=None, confirm=True):
"""
Copy the contents of an open file object (C{fl}) to the SFTP server as
C{remotepath}. Any exception raised by operations will be passed through.
The SFTP operations use pipelining for speed.
@param fl: opened file or file-like object to copy
@type localpath: object
@param remotepath: the destination path on the SFTP server
@type remotepath: str
@param file_size: optional size parameter passed to callback. If none is
specified, size defaults to 0
@type file_size: int
@param callback: optional callback function that accepts the bytes
transferred so far and the total bytes to be transferred
(since 1.7.4)
@type callback: function(int, int)
@param confirm: whether to do a stat() on the file afterwards to
confirm the file size (since 1.7.7)
@type confirm: bool
@return: an object containing attributes about the given file
(since 1.7.4)
@rtype: SFTPAttributes
@since: 1.4
"""
fr = self.file(remotepath, 'wb')
fr.set_pipelined(True)
size = 0
try:
while True:
data = fl.read(32768)
fr.write(data)
size += len(data)
if callback is not None:
callback(size, file_size)
if len(data) == 0:
break
finally:
fr.close()
if confirm:
s = self.stat(remotepath)
if s.st_size != size:
raise IOError('size mismatch in put! %d != %d' % (s.st_size, size))
else:
s = SFTPAttributes()
return s
def put(self, localpath, remotepath, callback=None, confirm=True):
"""
Copy a local file (C{localpath}) to the SFTP server as C{remotepath}.
Any exception raised by operations will be passed through. This
method is primarily provided as a convenience.
The SFTP operations use pipelining for speed.
@param localpath: the local file to copy
@type localpath: str
@param remotepath: the destination path on the SFTP server
@type remotepath: str
@param callback: optional callback function that accepts the bytes
transferred so far and the total bytes to be transferred
(since 1.7.4)
@type callback: function(int, int)
@param confirm: whether to do a stat() on the file afterwards to
confirm the file size (since 1.7.7)
@type confirm: bool
@return: an object containing attributes about the given file
(since 1.7.4)
@rtype: SFTPAttributes
@since: 1.4
"""
file_size = os.stat(localpath).st_size
fl = file(localpath, 'rb')
try:
return self.putfo(fl, remotepath, os.stat(localpath).st_size, callback, confirm)
finally:
fl.close()
def getfo(self, remotepath, fl, callback=None):
"""
Copy a remote file (C{remotepath}) from the SFTP server and write to
an open file or file-like object, C{fl}. Any exception raised by
operations will be passed through. This method is primarily provided
as a convenience.
@param remotepath: opened file or file-like object to copy to
@type remotepath: object
@param fl: the destination path on the local host or open file
object
@type localpath: str
@param callback: optional callback function that accepts the bytes
transferred so far and the total bytes to be transferred
(since 1.7.4)
@type callback: function(int, int)
@return: the number of bytes written to the opened file object
@since: 1.4
"""
fr = self.file(remotepath, 'rb')
file_size = self.stat(remotepath).st_size
fr.prefetch()
try:
size = 0
while True:
data = fr.read(32768)
fl.write(data)
size += len(data)
if callback is not None:
callback(size, file_size)
if len(data) == 0:
break
finally:
fr.close()
return size
def get(self, remotepath, localpath, callback=None):
"""
Copy a remote file (C{remotepath}) from the SFTP server to the local
host as C{localpath}. Any exception raised by operations will be
passed through. This method is primarily provided as a convenience.
@param remotepath: the remote file to copy
@type remotepath: str
@param localpath: the destination path on the local host
@type localpath: str
@param callback: optional callback function that accepts the bytes
transferred so far and the total bytes to be transferred
(since 1.7.4)
@type callback: function(int, int)
@since: 1.4
"""
file_size = self.stat(remotepath).st_size
fl = file(localpath, 'wb')
try:
size = self.getfo(remotepath, fl, callback)
finally:
fl.close()
s = os.stat(localpath)
if s.st_size != size:
raise IOError('size mismatch in get! %d != %d' % (s.st_size, size))
### internals...
def _request(self, t, *arg):
num = self._async_request(type(None), t, *arg)
return self._read_response(num)
def _async_request(self, fileobj, t, *arg):
# this method may be called from other threads (prefetch)
self._lock.acquire()
try:
msg = Message()
msg.add_int(self.request_number)
for item in arg:
if isinstance(item, int):
msg.add_int(item)
elif isinstance(item, long):
msg.add_int64(item)
elif isinstance(item, str):
msg.add_string(item)
elif isinstance(item, SFTPAttributes):
item._pack(msg)
else:
raise Exception('unknown type for %r type %r' % (item, type(item)))
num = self.request_number
self._expecting[num] = fileobj
self._send_packet(t, str(msg))
self.request_number += 1
finally:
self._lock.release()
return num
def _read_response(self, waitfor=None):
while True:
try:
t, data = self._read_packet()
except EOFError, e:
raise SSHException('Server connection dropped: %s' % (str(e),))
msg = Message(data)
num = msg.get_int()
if num not in self._expecting:
# might be response for a file that was closed before responses came back
self._log(DEBUG, 'Unexpected response #%d' % (num,))
if waitfor is None:
# just doing a single check
break
continue
fileobj = self._expecting[num]
del self._expecting[num]
if num == waitfor:
# synchronous
if t == CMD_STATUS:
self._convert_status(msg)
return t, msg
if fileobj is not type(None):
fileobj._async_response(t, msg, num)
if waitfor is None:
# just doing a single check
break
return (None, None)
def _finish_responses(self, fileobj):
while fileobj in self._expecting.values():
self._read_response()
fileobj._check_exception()
def _convert_status(self, msg):
"""
Raises EOFError or IOError on error status; otherwise does nothing.
"""
code = msg.get_int()
text = msg.get_string()
if code == SFTP_OK:
return
elif code == SFTP_EOF:
raise EOFError(text)
elif code == SFTP_NO_SUCH_FILE:
# clever idea from john a. meinel: map the error codes to errno
raise IOError(errno.ENOENT, text)
elif code == SFTP_PERMISSION_DENIED:
raise IOError(errno.EACCES, text)
else:
raise IOError(text)
def _adjust_cwd(self, path):
"""
Return an adjusted path if we're emulating a "current working
directory" for the server.
"""
if type(path) is unicode:
path = path.encode('utf-8')
if self._cwd is None:
return path
if (len(path) > 0) and (path[0] == '/'):
# absolute path
return path
if self._cwd == '/':
return self._cwd + path
return self._cwd + '/' + path
class SFTP (SFTPClient):
"an alias for L{SFTPClient} for backwards compatability"
pass