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Diffstat (limited to 'forward.py')
| -rw-r--r-- | forward.py | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/forward.py b/forward.py new file mode 100644 index 0000000..f91e969 --- /dev/null +++ b/forward.py @@ -0,0 +1,219 @@ +#!/usr/bin/python + +# Copyright (C) 2003-2005 Robey Pointer <robey@lag.net> +# +# 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 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 Paramiko; if not, write to the Free Software Foundation, Inc., +# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + +""" +Sample script showing how to do local port forwarding over paramiko. + +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 sys +import os +import socket +import select +import SocketServer +import getpass +import base64 +from optparse import OptionParser + +import paramiko + +DEFAULT_PORT = 4000 +SSH_PORT = 22 +VERBOSE = True +READPASS = False + + +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 + + verbose('Connected! Tunnel open.') + 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.') + + +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 find_default_key_file(): + filename = os.path.expanduser('~/.ssh/id_rsa') + if os.access(filename, os.R_OK): + return filename + filename = os.path.expanduser('~/ssh/id_rsa') + if os.access(filename, os.R_OK): + return filename + filename = os.path.expanduser('~/.ssh/id_dsa') + if os.access(filename, os.R_OK): + return filename + filename = os.path.expanduser('~/ssh/id_dsa') + if os.access(filename, os.R_OK): + return filename + return '' + +def verbose(s): + if VERBOSE: + print s + + +##### + + +parser = OptionParser(usage='usage: %prog [options] <remote-addr>:<remote-port>', + version='%prog 1.0') +parser.add_option('-q', '--quiet', action='store_false', dest='verbose', default=VERBOSE, + help='squelch all informational output') +parser.add_option('-l', '--local-port', action='store', type='int', dest='port', + default=DEFAULT_PORT, + help='local port to forward (default: %d)' % DEFAULT_PORT) +parser.add_option('-r', '--host', action='store', type='string', dest='ssh_host', + help='SSH host to tunnel through (required)') +parser.add_option('-p', '--port', action='store', type='int', dest='ssh_port', default=SSH_PORT, + help='SSH port to tunnel through (default: %d)' % SSH_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=find_default_key_file(), + help='private key file to use for SSH authentication') +parser.add_option('', '--no-key', action='store_false', dest='use_key', default=True, + help='don\'t look for or use a private key file') +parser.add_option('-P', '--password', action='store_true', dest='readpass', default=READPASS, + help='read password (for key or password auth) from stdin') +options, args = parser.parse_args() + +VERBOSE = options.verbose +READPASS = options.readpass + + +if len(args) != 1: + parser.error('Incorrect number of arguments.') +remote_host = args[0] +if ':' not in remote_host: + parser.error('Remote port missing.') +remote_host, remote_port = remote_host.split(':', 1) +try: + remote_port = int(remote_port) +except: + parser.error('Remote port must be a number.') + +if not options.ssh_host: + parser.error('SSH host is required.') +if ':' in options.ssh_host: + options.ssh_host, options.ssh_port = options.ssh_host.split(':', 1) + try: + options.ssh_port = int(options.ssh_port) + except: + parser.error('SSH port must be a number.') + +try: + host_keys = paramiko.util.load_host_keys(os.path.expanduser('~/.ssh/known_hosts')) +except IOError: + try: + host_keys = paramiko.util.load_host_keys(os.path.expanduser('~/ssh/known_hosts')) + except IOError: + print '*** Unable to open host keys file' + host_keys = {} + +if not host_keys.has_key(options.ssh_host): + print '*** Warning: no host key for %s' % options.ssh_host + expected_host_key_type = None + expected_host_key = None +else: + expected_host_key_type = host_keys[options.ssh_host].keys()[0] + expected_host_key = host_keys[options.ssh_host][expected_host_key_type] + +key = None +password = None +if options.use_key: + try: + key = paramiko.RSAKey.from_private_key_file(options.keyfile) + except paramiko.PasswordRequiredException: + if not READPASS: + print '*** Password needed for keyfile (use -P): %s' % options.keyfile + sys.exit(1) + key_password = getpass.getpass('Enter password for key: ') + try: + key = paramiko.RSAKey.from_private_key_file(options.keyfile, key_password) + except: + print '*** Unable to read keyfile: %s' % options.keyfile + sys.exit(1) + except: + pass + +if key is None: + # try reading a password then + if not READPASS: + print '*** Either a valid private key or password is required (use -K or -P).' + sys.exit(1) + password = getpass.getpass('Enter password: ') + +verbose('Connecting to ssh host %s:%d ...' % (options.ssh_host, options.ssh_port)) + +transport = paramiko.Transport((options.ssh_host, options.ssh_port)) +transport.connect(hostkeytype=expected_host_key_type, + hostkey=expected_host_key, + username=options.user, + password=password, + pkey=key) + +verbose('Now forwarding port %d to %s:%d ...' % (options.port, remote_host, remote_port)) + +try: + forward_tunnel(options.port, remote_host, remote_port, transport) +except KeyboardInterrupt: + print 'Port forwarding stopped.' + sys.exit(0) |