'captive can be either run redirecting to a specified url (--portalurl), serve the payload locally (no argument) or
start an instance of SimpleHTTPServer to serve the LOCALDIR (--portaldir)'

def options(self, options):

    group = options.add_mutually_exclusive_group(required=False)
    group.add_argument('--portalurl', dest='portalurl', metavar='URL', help='Specify    the    URL    where    the    portal    is    located,    e.g.    http://example.com.')
    group.add_argument('--portaldir', dest='portaldir', metavar='LOCALDIR', help='Specify    a    local    path    containg    the    portal    files    served    with    a    SimpleHTTPServer    on    a    different    port    (see    config).')
    options.add_argument('--use-dns', dest='usedns', action='store_true', help='Whether    we    use    dns    spoofing    to    serve    from    a    fancier    portal    URL    captive.portal    when    used    without    options    or    portaldir.    Requires    DNS    for    "captive.portal"    to    resolve,    e.g.    via    configured    dns    spoofing    --dns.')
