181 lines
6.7 KiB
Python
181 lines
6.7 KiB
Python
#!/usr/bin/env python
|
|
|
|
# Copyright (C) 2011 Jeff Forcier <jeff@bitprophet.org>
|
|
#
|
|
# This file is part of ssh.
|
|
#
|
|
# 'ssh' 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.
|
|
#
|
|
# 'ssh' is distrubuted 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 'ssh'; if not, write to the Free Software Foundation, Inc.,
|
|
# 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA.
|
|
|
|
"""
|
|
Sample script showing how to do local port forwarding over ssh.
|
|
|
|
This script connects to the requested SSH server and sets up local port
|
|
forwarding (the openssh -L option) from a local port through a tunneled
|
|
connection to a destination reachable from the SSH server machine.
|
|
"""
|
|
|
|
import getpass
|
|
import os
|
|
import socket
|
|
import select
|
|
import SocketServer
|
|
import sys
|
|
from optparse import OptionParser
|
|
|
|
import ssh
|
|
|
|
SSH_PORT = 22
|
|
DEFAULT_PORT = 4000
|
|
|
|
g_verbose = True
|
|
|
|
|
|
class ForwardServer (SocketServer.ThreadingTCPServer):
|
|
daemon_threads = True
|
|
allow_reuse_address = True
|
|
|
|
|
|
class Handler (SocketServer.BaseRequestHandler):
|
|
|
|
def handle(self):
|
|
try:
|
|
chan = self.ssh_transport.open_channel('direct-tcpip',
|
|
(self.chain_host, self.chain_port),
|
|
self.request.getpeername())
|
|
except Exception, e:
|
|
verbose('Incoming request to %s:%d failed: %s' % (self.chain_host,
|
|
self.chain_port,
|
|
repr(e)))
|
|
return
|
|
if chan is None:
|
|
verbose('Incoming request to %s:%d was rejected by the SSH server.' %
|
|
(self.chain_host, self.chain_port))
|
|
return
|
|
|
|
verbose('Connected! Tunnel open %r -> %r -> %r' % (self.request.getpeername(),
|
|
chan.getpeername(), (self.chain_host, self.chain_port)))
|
|
while True:
|
|
r, w, x = select.select([self.request, chan], [], [])
|
|
if self.request in r:
|
|
data = self.request.recv(1024)
|
|
if len(data) == 0:
|
|
break
|
|
chan.send(data)
|
|
if chan in r:
|
|
data = chan.recv(1024)
|
|
if len(data) == 0:
|
|
break
|
|
self.request.send(data)
|
|
chan.close()
|
|
self.request.close()
|
|
verbose('Tunnel closed from %r' % (self.request.getpeername(),))
|
|
|
|
|
|
def forward_tunnel(local_port, remote_host, remote_port, transport):
|
|
# this is a little convoluted, but lets me configure things for the Handler
|
|
# object. (SocketServer doesn't give Handlers any way to access the outer
|
|
# server normally.)
|
|
class SubHander (Handler):
|
|
chain_host = remote_host
|
|
chain_port = remote_port
|
|
ssh_transport = transport
|
|
ForwardServer(('', local_port), SubHander).serve_forever()
|
|
|
|
|
|
def verbose(s):
|
|
if g_verbose:
|
|
print s
|
|
|
|
|
|
HELP = """\
|
|
Set up a forward tunnel across an SSH server, using ssh. A local port
|
|
(given with -p) is forwarded across an SSH session to an address:port from
|
|
the SSH server. This is similar to the openssh -L option.
|
|
"""
|
|
|
|
|
|
def get_host_port(spec, default_port):
|
|
"parse 'hostname:22' into a host and port, with the port optional"
|
|
args = (spec.split(':', 1) + [default_port])[:2]
|
|
args[1] = int(args[1])
|
|
return args[0], args[1]
|
|
|
|
|
|
def parse_options():
|
|
global g_verbose
|
|
|
|
parser = OptionParser(usage='usage: %prog [options] <ssh-server>[:<server-port>]',
|
|
version='%prog 1.0', description=HELP)
|
|
parser.add_option('-q', '--quiet', action='store_false', dest='verbose', default=True,
|
|
help='squelch all informational output')
|
|
parser.add_option('-p', '--local-port', action='store', type='int', dest='port',
|
|
default=DEFAULT_PORT,
|
|
help='local port to forward (default: %d)' % DEFAULT_PORT)
|
|
parser.add_option('-u', '--user', action='store', type='string', dest='user',
|
|
default=getpass.getuser(),
|
|
help='username for SSH authentication (default: %s)' % getpass.getuser())
|
|
parser.add_option('-K', '--key', action='store', type='string', dest='keyfile',
|
|
default=None,
|
|
help='private key file to use for SSH authentication')
|
|
parser.add_option('', '--no-key', action='store_false', dest='look_for_keys', default=True,
|
|
help='don\'t look for or use a private key file')
|
|
parser.add_option('-P', '--password', action='store_true', dest='readpass', default=False,
|
|
help='read password (for key or password auth) from stdin')
|
|
parser.add_option('-r', '--remote', action='store', type='string', dest='remote', default=None, metavar='host:port',
|
|
help='remote host and port to forward to')
|
|
options, args = parser.parse_args()
|
|
|
|
if len(args) != 1:
|
|
parser.error('Incorrect number of arguments.')
|
|
if options.remote is None:
|
|
parser.error('Remote address required (-r).')
|
|
|
|
g_verbose = options.verbose
|
|
server_host, server_port = get_host_port(args[0], SSH_PORT)
|
|
remote_host, remote_port = get_host_port(options.remote, SSH_PORT)
|
|
return options, (server_host, server_port), (remote_host, remote_port)
|
|
|
|
|
|
def main():
|
|
options, server, remote = parse_options()
|
|
|
|
password = None
|
|
if options.readpass:
|
|
password = getpass.getpass('Enter SSH password: ')
|
|
|
|
client = ssh.SSHClient()
|
|
client.load_system_host_keys()
|
|
client.set_missing_host_key_policy(ssh.WarningPolicy())
|
|
|
|
verbose('Connecting to ssh host %s:%d ...' % (server[0], server[1]))
|
|
try:
|
|
client.connect(server[0], server[1], username=options.user, key_filename=options.keyfile,
|
|
look_for_keys=options.look_for_keys, password=password)
|
|
except Exception, e:
|
|
print '*** Failed to connect to %s:%d: %r' % (server[0], server[1], e)
|
|
sys.exit(1)
|
|
|
|
verbose('Now forwarding port %d to %s:%d ...' % (options.port, remote[0], remote[1]))
|
|
|
|
try:
|
|
forward_tunnel(options.port, remote[0], remote[1], client.get_transport())
|
|
except KeyboardInterrupt:
|
|
print 'C-c: Port forwarding stopped.'
|
|
sys.exit(0)
|
|
|
|
|
|
if __name__ == '__main__':
|
|
main()
|