#!/usr/bin/env python
# -*- coding: iso-8859-1 -*-

"""Command line interface.
"""

# Copyright (C) 2004, 2005, 2006 Juan M. Bello Rivas <jmbr+halberd@superadditive.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA


import sys

import Halberd.shell
import Halberd.logger
import Halberd.ScanTask
import Halberd.version as version


def make_parser():
    """Sets up the command line option parser.
    """
    import optparse

    notice = version.version.v_gnu + '\n\n' + \
r"""Copyright (C) 2004, 2005, 2006 Juan M. Bello Rivas <jmbr@superadditive.com>

This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE."""

    parser = optparse.OptionParser(usage='%prog [OPTION]... URL',
                                   version=notice)
    parser.set_description("Discover web servers behind HTTP load balancers.")

    parser.add_option('-v', '--verbose', action='store_true', dest='verbose',
                      help='explain what is being done', default=True)
    parser.add_option('-q', '--quiet', action='store_false', dest='verbose',
                      help='run quietly', default=True)
    # xxx - use increment over verbosity level instead of this
    parser.add_option('-d', '--debug', action='store_true', dest='debug',
                      help='enable debugging information', default=False)

    parser.add_option('-t', '--time',
                      action='store', type='int', dest='scantime',
                      help='time (in seconds) to spend scanning the target',
                      metavar='NUM', default=Halberd.ScanTask.default_scantime)

    parser.add_option('-p', '--parallelism', action='store', type='int',
                      dest='parallelism',
                      help='specify the number of parallel threads to use',
                      metavar='NUM', default=Halberd.ScanTask.default_parallelism)

    parser.add_option('-u', '--urlfile', action='store', dest='urlfile',
                      help='read URLs from FILE', metavar='FILE')

    parser.add_option('-o', '--out', action='store', dest='output',
                      help='write report to the specified file',
                      metavar='FILE', default='')

    parser.add_option('-a', '--address', action='store', dest='addr',
                      help='specify address to scan',
                      metavar='ADDR', default='')

    parser.add_option('-r', '--read', action='store', dest='cluefile',
                      help='load clues from the specified file',
                      metavar='FILE', default='')
    parser.add_option('-w', '--write', action='store', dest='save',
                      help='save clues to the specified directory',
                      metavar='DIR', default='')

    parser.add_option('', '--config', action='store', dest='confname',
                      help='use alternative configuration file',
                      metavar='FILE',
                      default=Halberd.ScanTask.default_conf_file)

    return parser


def make_url(url):
    """Ensures the URL is a valid one.

    Characters aren't escaped, so strings like 'htt%xx://' won't be parsed.

    @param url: An incomplete (or not) URL.
    @type url: C{str}
    """
    if url.startswith('http://') or url.startswith('https://'):
        newurl = url
    else:
        newurl = 'http://' + url

    return newurl


def scannerFactory(opts, args):
    """Instantiates a scanner of the appropriate flavour.

    It selects which scanning strategy to follow depending on how the user
    invoked the program.
    """
    scantask = Halberd.ScanTask.ScanTask()

    scantask.scantime = opts.scantime
    scantask.parallelism = opts.parallelism
    scantask.verbose = opts.verbose
    scantask.debug = opts.debug
    scantask.conf_file = opts.confname
    scantask.cluefile = opts.cluefile
    scantask.save = opts.save
    scantask.output = opts.output

    # Set logging level.
    if not scantask.verbose:
        Halberd.logger.setError()
    if scantask.debug:
        Halberd.logger.setDebug()

    scantask.readConf()

    if opts.cluefile:
        # Read and analyze clues.
        scanner = Halberd.shell.ClueReaderStrategy
    elif opts.urlfile:
        # MultiScan
        scantask.urlfile = opts.urlfile
        scanner = Halberd.shell.MultiScanStrategy
    elif len(args) > 0:
        # UniScan
        scantask.url = make_url(args[0])
        scantask.addr = opts.addr
        scanner = Halberd.shell.UniScanStrategy
    else:
        return None

    return scanner(scantask)


def main(argv):
    """Command line interface.
    """
    parser = make_parser()

    (opts, args) = parser.parse_args(argv[1:])

    if opts.verbose:
        print version.version.v_gnu
        print

    try:
        scanner = scannerFactory(opts, args)
        if scanner is None:
            parser.error('incorrect number of arguments')
        scanner.execute()
    except Halberd.shell.ScanError, msg:
        sys.stderr.write('\n*** %s ***\n' % msg)
    except KeyboardInterrupt:
        sys.stderr.write('\r*** interrupted by the user ***\n')


if __name__ == '__main__':
#    import gc
#    gc.set_debug(gc.DEBUG_LEAK)
    main(sys.argv)


# vim: ts=4 sw=4 et