wbbd.py

#!/usr/bin/env python

"""
Copyright (c) 2011 Locker537 <github.com/Locker537>

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.
"""

#Imports
from optparse import OptionParser
import subprocess
import urllib2
import sys
import os
import re

def validateParameters(options):
    """
    Who needs documentation
    TODO: Add some...
    """

    #options.identity should be a valid file
    if os.path.isfile(options.identity):
        try:
            f = open(options.identity, "r")
        except IOError as err:
            print "Could not open the identity file %s for reading, exiting." % options.identity
            sys.exit(1)
        finally:
            f.close()
    else:
        print "Could not find the identity file %s, exiting." % options.identity
        sys.exit(1)

    #options.rport, options.lport, and options.port should be numeric
    if not options.rport.isdigit() or not options.lport.isdigit() or not options.port.isdigit():
        print "rport:%s lport:%s port:%s" % (options.rport, options.lport, options.port)
        print "rport, lport, and port options must all be numbers, exiting."
        sys.exit(1)

    #options.host should be an IP or a hostname
    validIpAddressRegex = "^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])$"

    validHostnameRegex = "^(([a-zA-Z]|[a-zA-Z][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])$"

    if not re.match(validIpAddressRegex, options.host) and  not re.match(validHostnameRegex, options.host):
        print "Supplied host: %s" % options.host
        print "Host appears to not be a valid host, exiting."
        sys.exit(1)

    #If we made it this far, we can return True
    return True
    
def currentlyRunning(cmd):
    """
    Who needs documentation...
    TODO: Add some...
    """
    
    s = "ps -elf | grep \"%s\" | grep -v grep | wc -l" % cmd[0:10]
    x = subprocess.Popen(s, shell=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    out, err = x.communicate()

    if int(out.strip()):
        return True
    
    return False
    
def popShell(identity, rport, lport, port, username, host):
    """
    Who needs documentation...
    TODO: Add some...
    """

    #TODO: Probably should not redirect stdout and stderr so forcefully. Let Popen handle it.
    cmd = "ssh -R %s:127.0.0.1:%s -i %s -p %s -l %s %s -N  > /dev/null 2>&1 &" % \
        (rport, lport, identity, port, username, host)

    #Check to see if cmd is already running
    if not currentlyRunning(cmd):
        print "Trying to open a new SSH session..."
        x = subprocess.Popen(cmd, shell=True)
    
    else:
        print "SSH with those parameters already running..."

def fetchPage(url):
    """
    Who needs documentation...
    TODO: Add some...
    """
    
    #TODO: Add some URL validation. Mo' regex...
    try:
        page = urllib2.urlopen(url)
    
    except ValueError as err:
        #User gave a funky URL...
        print err
        print "You gave a weird url: %s" % url
        print "Exiting."
        sys.exit(1)

    except urllib2.HTTPError as err:
        #We got an HTTP Error, such as a 404 Not Found...
        return False
    
    else:
        #No error, so check and see if we got "good" results
        if page:
            return True

if __name__ == "__main__":
    
    #Handle all the command line args...
    parser = OptionParser()

    parser.add_option("-i", "--identity", action = "store", type = "string", \
                          dest = "identity", help = "SSH identity file (full path helps)", default = None)

    parser.add_option("-r", "--rport", action = "store", type = "string", \
                          dest = "rport", help = "Remote port to listen on and forward back to lport", \
                          default = "12345")

    parser.add_option("-L", "--lport", action = "store", type = "string", \
                          dest = "lport", help = "Local port to forward back to", default = "22")

    parser.add_option("-p", "--port", action = "store", type = "string", \
                          dest = "port", help = "SSH port for initial outbound connect", default = "22")

    parser.add_option("-l", "--user", action = "store", type = "string", dest = "user", \
                           help = "SSH User name", default = None)

    parser.add_option("-H", "--host", action = "store", type = "string", dest = "host", \
                          help = "Remote hostname or ip", default = None)

    parser.add_option("-u", "--url", action = "store", type = "string", dest = "url", \
                          help = "URL to fetch and use as switch for running the SSH session", \
                          default = None)
    
    (options, args) = parser.parse_args()

    #Validate basic args
    if not options.url:
        print "URL is a mandatory option!"
        print "See help for more information. \n"
        parser.print_help()

    elif not options.identity or not options.user or not options.host:
        print "Identity, user, and host are currently all mandatory options!"
        print "See help for more information.\n"
        parser.print_help()

    else:
        #Then really validate some args for data
        if validateParameters(options):
            print "Parameters look good, fetching url..."
            
            if fetchPage(options.url):
                print "Fetched page, trying to SSH..."
                popShell(options.identity, options.rport, options.lport, \
                             options.port, options.user, options.host)

            else:
                print "No page to fetch, exiting without trying to SSH..."
                sys.exit(0)