sshtunnel.py

#! /usr/bin/python
# -*- coding: utf-8 -*-
#
# Copyright (c) 2009-2010 Sauce Labs Inc
# Copyright (c) 2001-2004 Twisted Matrix Laboratories.
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# 'Software'), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

import time
import struct
import sys
import os
import saucerest

from twisted.conch.ssh import (connection, channel,
                               userauth, keys, common,
                               transport, forwarding)
from twisted.internet import defer, protocol, reactor, task
from twisted.internet.task import LoopingCall

class TunnelTransport(transport.SSHClientTransport):

    def __init__(self,
                 user,
                 password,
                 forward_host,
                 forward_port,
                 forward_remote_port,
                 connected_callback=None,
                 diagnostic=False):
        try:
            transport.SSHClientTransport.__init__(self)
        except AttributeError:
            pass
        self.user = user
        self.password = password
        self.forward_host = forward_host
        self.forward_port = forward_port
        self.forward_remote_port = forward_remote_port
        self.connected_callback = connected_callback
        self.diagnostic = diagnostic

    def verifyHostKey(self, hostKey, fingerprint):
        return defer.succeed(1)

    def connectionSecure(self):
        self.requestService(
            TunnelUserAuth(self.user,
                           TunnelConnection(self.forward_host,
                           self.forward_port,
                           self.forward_remote_port,
                           self.connected_callback,
                           self.diagnostic),
                           self.password))


class TunnelUserAuth(userauth.SSHUserAuthClient):

    def __init__(self, user, connection, password):
        userauth.SSHUserAuthClient.__init__(self, user, connection)
        self.password = password

    def getPassword(self):
        return defer.succeed(self.password)

    def getGenericAnswers(self, name, instruction, questions):
        print "name:", name
        print "instruction:", instruction
        print "questions:", questions
        answers = []
        for prompt, echo in questions:
            answer = self.password
            answers.append(answer)
        return defer.succeed(answers)

    def getPublicKey(self):
        return

    def getPrivateKey(self):
        return


class _KeepAlive:

    def __init__(self, conn):
        self.conn = conn
        self.globalTimeout = None
        self.lc = task.LoopingCall(self.sendGlobal)
        self.lc.start(300)

    def sendGlobal(self):
        d = self.conn.sendGlobalRequest("tunnel-keep-alive@saucelabs.com",
                                        "",
                                        wantReply = 1)
        d.addBoth(self._cbGlobal)
        self.globalTimeout = reactor.callLater(30, self._ebGlobal)

    def _cbGlobal(self, res):
        if self.globalTimeout:
            self.globalTimeout.cancel()
            self.globalTimeout = None

    def _ebGlobal(self):
        if self.globalTimeout:
            self.globalTimeout = None
            self.conn.transport.loseConnection()


class TunnelConnection(connection.SSHConnection):

    def __init__(self,
                 forward_host,
                 forward_port,
                 forward_remote_port,
                 connected_callback=None,
                 diagnostic=False):
        try:
            connection.SSHConnection.__init__(self)
        except AttributeError:
            pass

        self.forward_host = forward_host
        self.forward_port = forward_port
        self.forward_remote_port = forward_remote_port
        self.connected_callback = connected_callback
        self.diagnostic = diagnostic

    def serviceStarted(self):
        self.remoteForwards = {}
        if hasattr(self.transport, 'sendIgnore'):
            _KeepAlive(self)
        self.requestRemoteForwarding(self.forward_remote_port,
                                    (self.forward_host, self.forward_port))
        self.openChannel(NullChannel())

    def requestRemoteForwarding(self, remotePort, hostport):
        data = forwarding.packGlobal_tcpip_forward(('0.0.0.0', remotePort))
        d = self.sendGlobalRequest('tcpip-forward',
                                   data,
                                   wantReply=1)
        print('requesting remote forwarding %s=>%s:%s' %(remotePort, hostport[0],hostport[1]))
        d.addCallback(self._cbRemoteForwarding, remotePort, hostport)
        d.addErrback(self._ebRemoteForwarding, remotePort, hostport)

    def _cbRemoteForwarding(self, result, remotePort, hostport):
        print('accepted remote forwarding %s=>%s:%s' %(remotePort, hostport[0],hostport[1]))
        self.remoteForwards[remotePort] = hostport
        if self.connected_callback:
            self.connected_callback()

    def _ebRemoteForwarding(self, f, remotePort, hostport):
        print('remote forwarding %s=>%s:%s failed' %(remotePort, hostport[0],hostport[1]))
        print(f)

    def cancelRemoteForwarding(self, remotePort):
        data = forwarding.packGlobal_tcpip_forward(('0.0.0.0', remotePort))
        self.sendGlobalRequest('cancel-tcpip-forward', data)
        print('cancelling remote forwarding %s' % remotePort)
        try:
            del self.remoteForwards[remotePort]
        except:
            pass

    def channel_forwarded_tcpip(self, winSize, maxP, data):
        if self.diagnostic:
            print('FTCP %s' % repr(data))
        remoteHP, origHP = forwarding.unpackOpen_forwarded_tcpip(data)
        if self.diagnostic:
            print(remoteHP)
        if remoteHP[1] in self.remoteForwards:
            connectHP = self.remoteForwards[remoteHP[1]]
            if self.diagnostic:
                print('connect forwarding ', connectHP)
            return forwarding.SSHConnectForwardingChannel(connectHP,
                                                          remoteWindow=winSize,
                                                          remoteMaxPacket=maxP,
                                                          conn = self)
        else:
            raise ConchError(connection.OPEN_CONNECT_FAILED,
                             "don't know about that port")

    def channelClosed(self, channel):
        if self.diagnostic:
            print('connection closing %s' % channel)
            print(self.channels)
        if len(self.channels) == 1: # just us left
            print('stopping connection to a closed tunnel')
            try:
                #dont stop reactor when one connection is closed
                self.__class__.__bases__[0].channelClosed(self, channel)
            except:
                pass
        else:
            # because of the unix thing
            self.__class__.__bases__[0].channelClosed(self, channel)


class NullChannel(channel.SSHChannel):

    name = 'session'

    def openFailed(self, reason):
        print 'NullChannel open failed', reason

    def channelOpen(self, ignoredData):
        return

    def closeReceived(self):
        print('remote side closed %s' % self)
        self.conn.sendClose(self)

    def closed(self):
        global old
        print('closing channel')

"""
Tunnel handling:
"""

open_tunnels = 0

def connect_tunnel(tunnel_id,
                 base_url,
                 username,
                 access_key,
                 local_host,
                 remote_host,
                 ports,
                 connected_callback,
                 shutdown_callback,
                 diagnostic):

    def check_n_call():
        global open_tunnels
        open_tunnels += 1
        if open_tunnels >= len(ports) and connected_callback:
            connected_callback()

    for (local_port, remote_port) in ports:
        d = protocol.ClientCreator(reactor,
                                   TunnelTransport,
                                   username,
                                   access_key,
                                   local_host,
                                   local_port,
                                   remote_port,
                                   check_n_call,
                                   diagnostic).connectTCP(remote_host, 22)

    reactor.addSystemEventTrigger("before", "shutdown", shutdown_callback)