Mailman 3 Re: [Twisted-Python] twisted python conch SSH shell? - Twisted

Aug. 21, 2008


      conchClient.py is libarary. Running it from the command line was an
afterthought just for testing.
To run multiple commands in the same session you just give sshCmds a
list of commands to run and it will return the output of all of them.
Here is an example script that creates a function to up a port and
another to return the wwn (this is from a SAN switch) of a port.

#!/usr/bin/env python
# Eli Criffield

__version__ = 0.1186070837
__author__ = 'Eli Criffield <python AT zendo.net>'

import sys
import re
import time
import os
from conchClient import sshCmds

dryRun = False
Confirm = True
echo = False

class reError(Exception):
    pass

def execList(switch,cmds,change=False):
    global echo, dryRun, Confirm
    # if change is False, the commands arn't suppose to do any damage
    # always exec them, they need the info
    if not change:
        return sshCmds(switch,cmds,echo=echo)

    if dryRun:
        print 'DRY RUN'
        print 'ssh %s'%switch
        for cmd in cmds:
            print cmd
        print 'ENTER to continue:',
        sys.stdin.readline()
        return ('dryrun','')


    if Confirm:
        print "I'm going to run:"
        print '\nssh %s'%switch
        for cmd in cmds:
            print cmd
        ans = raw_input('Does that look ok (yes/no)? ')
        while ans.lower() not in ('yes', 'no'):
            ans = raw_input("Please type 'yes' or 'no': ")
        if ans == 'no':
            print 'exiting out'
            sys.exit(1)
        else:
            return sshCmds(switch,cmds,echo=echo)

    # No dryRun or Confirm just execute it
    return sshCmds(switch,cmds,echo=echo)

def upPort(switch,port):
    cmds=[ 'config term', 'interface fc%s'%port, 'no shutdown' ,'end'
    ,'exit' ]
    execList(switch,cmds,change=True)

def wwnFromPort(switch,port):
    portre = re.compile(r'%s '%port)
    linere = re.compile(r'(\S*)\s*(\S*)\s*(\S*)\s*(\S*)\s*(\S*)')
    (out,err) = execList(switch,['show flogi database'])
    for line in out.split('fc'):
        if portre.match(line):
            #print 'line:',line #DEBUG
            wwn = linere.match(line).groups()[3]
            #print wwn #DEBUG
            return wwn


On Thu, Aug 21, 2008 at 2:07 AM, The Noob <thenoob06@gmail.com> wrote:
...
Hello,
If I understand your code, you can't find a way to run a real shell on Cisco
?
For example if I connect to a router, I send a "sh log" , " conf t "
commands but I do not know them before. With the actual script:
conchClient.py 192.168.0.254 sh log
The script disconnects us from the router
conchClient.py 192.168.0.254 conf t
The script disconnects us  disconnect from the router
I think the problem with your script it is for each command you are
disconnected The best will be to find a solution to do this:
conchClient.py 192.168.0.254 sh log
conchClient.py 192.168.0.254 conf t
conchClient.py 192.168.0.254 exit
disconnect from server
I try to do this with a custom ssh server which permits to connect to others
ssh servers and have a shell. But I don't know how to communicate between my
custom ssh server and my child ( an expect script which launch ssh root@host
and permits to have a real shell)
Best Regards
TheNoob06
2008/8/21 Eli Criffield <elicriffield@gmail.com>
...
check out
http://twistedmatrix.com/pipermail/twisted-python/2007-July/015793.html
Eli Criffield
On Tue, Aug 12, 2008 at 3:40 PM, Bill Zeller <wzeller@cs.princeton.edu>
wrote:
...
Hi,
I've been playing around with Twisted's Conch client (which looks
extremely
well done, thanks!). I've been able to connect to a conch server and
also
connect to other ssh servers and execuate various commands. I'd like to
be
able to connect to an arbitrary SSH server and run /bin/bash.
I'm able to execute a command like so:
---------------------
class CommandChannel(channel.SSHChannel):
    ....
    def channelOpen(self, data):
        self.conn.sendRequest(
            self, 'exec', common.NS(self.command),
wantReply=True).addCallback(
            self._gotResponse)
---------------------
Looking through the SSH spec (connect protocol, rfc4254), it looks like
shells are opened with this command.
---------------------
byte      SSH_MSG_CHANNEL_REQUEST
uint32    recipient channel
      string    "shell"
      boolean   want reply
---------------------
It doesn't look like Conch supports these requests (here's how
CHANNEL_REQUESTs are currently sent out)
---------------------
(Twisted-8.1.0)
twisted/conch/ssh/connection.py (413):
        self.transport.sendPacket(MSG_CHANNEL_REQUEST, struct.pack('>L',
self.channelsToRemoteChannel[channel])
                                  +
common.NS(requestType)+chr(wantReply)
                                  + data)
---------------------
I may be misunderstanding how remote shells are started, so any help
would
be appreciated.
Again, I'm trying to launch an interactive /bin/bash shell from a Conch
SSH
client on an arbitrary remote SSH server.
Thanks for your time.
Best Regards,
Bill Zeller
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Re: [Twisted-Python] twisted python conch SSH shell?

Eli Criffield

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