1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
|
#!/usr/bin/env python
# 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.
"""
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 getpass
import os
import socket
import select
import SocketServer
import sys
from optparse import OptionParser
import paramiko
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)
peername = self.request.getpeername()
chan.close()
self.request.close()
verbose('Tunnel closed from %r' % (peername,))
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 paramiko. 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 = paramiko.SSHClient()
client.load_system_host_keys()
client.set_missing_host_key_policy(paramiko.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()
|
