#!/usr/bin/python2
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2010  Marek Marczykowski <marmarek@invisiblethingslab.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., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
#
#

from qubes.qubes import QubesVmCollection, QubesException
from qubes.qubesutils import block_list,block_attach,block_detach,block_detach_all,block_check_attached
from qubes.qubesutils import kbytes_to_kmg, bytes_to_kmg
from optparse import OptionParser
import subprocess
import sys
import os

def main():
    usage = "usage: %prog -l [options]\n"\
            "usage: %prog -a [options] <vm-name> <device-vm-name>:<device>\n"\
            "usage: %prog -A [options] <vm-name> <file-vm-name>:<file>\n"\
            "usage: %prog -d [options] <device-vm-name>:<device>\n"\
            "usage: %prog -d [options] <vm-name>\n"\
            "List/set VM block devices."

    parser = OptionParser (usage)
    parser.add_option ("-l", "--list", action="store_true", dest="do_list", default=False)
    parser.add_option ("-A", "--attach-file", action="store_true", dest="do_file_attach", default=False,
                        help="Attach specified file instead of physical device")
    parser.add_option ("-a", "--attach", action="store_true", dest="do_attach", default=False)
    parser.add_option ("-d", "--detach", action="store_true", dest="do_detach", default=False)
    parser.add_option ("-f", "--frontend", dest="frontend", 
                        help="Specify device name at destination VM [default: xvdi]")
    parser.add_option ("--ro", dest="ro", action="store_true", default=False,
                        help="Force read-only mode")
    parser.add_option ("--no-auto-detach", dest="auto_detach", action="store_false", default=True,
                        help="Fail when device already connected to other VM")
    parser.add_option ("--show-system-disks", dest="system_disks", action="store_true", default=False,
                        help="List also system disks")
    parser.add_option ("--force-root", action="store_true", dest="force_root", default=False,
                       help="Force to run, even with root privileges")

    (options, args) = parser.parse_args ()

    if os.geteuid() == 0:
        if not options.force_root:
            print >> sys.stderr, "*** Running this tool as root is strongly discouraged, this will lead you in permissions problems."
            print >> sys.stderr, "Retry as unprivileged user."
            print >> sys.stderr, "... or use --force-root to continue anyway."
            exit(1)

    if options.do_file_attach:
        options.do_attach = True

    if options.do_list + options.do_attach + options.do_detach > 1:
        print >> sys.stderr, "Only one of -l -a/-A -d is allowed!"
        exit (1)

    if options.do_attach or options.do_detach:
        qvm_collection = QubesVmCollection()
        qvm_collection.lock_db_for_reading()
        qvm_collection.load()
        qvm_collection.unlock_db()

    if options.do_attach:
        if (len (args) < 2):
            parser.error ("You must provide device and vm name!")
        vm = qvm_collection.get_vm_by_name(args[0])
        if vm is None:
            parser.error ("Invalid VM name: %s" % args[0])
        # FIXME: here we assume that device is always in form "domain:dev", which can be changed in the future
        if args[1].find(":") < 0:
            parser.error ("Invalid device syntax" % args[1])
        if options.do_file_attach:
            dev = {}
            (dev['vm'], dev['device']) = args[1].split(":")
            dev['mode'] = 'w'
        else:
            dev_list = block_list()
            if not args[1] in dev_list.keys():
                parser.error ("Invalid device name: %s" % args[1])
            dev = dev_list[args[1]]
        backend_vm = qvm_collection.get_vm_by_name(dev['vm'])
        assert backend_vm is not None
        kwargs = {}
        if options.frontend:
            kwargs['frontend'] = options.frontend
        if options.ro:
            kwargs['mode'] = "r"
        else:
            kwargs['mode'] = dev['mode']
        kwargs['auto_detach'] = options.auto_detach
        try:
            block_attach(vm, backend_vm, dev['device'], **kwargs)
        except QubesException as e:
            print >> sys.stderr, "ERROR: %s" % str(e)
            sys.exit(1)
    elif options.do_detach:
        if (len (args) < 1):
            parser.error ("You must provide device or vm name!")
        # Check if provided name is VM
        vm = qvm_collection.get_vm_by_name(args[0])
        if vm is not None:
            kwargs = {}
            if options.frontend:
                kwargs['frontend'] = options.frontend
                block_detach(vm, **kwargs)
            else:
                block_detach_all(vm)
        else:
            # Maybe device?
            dev_list = block_list()
            if not args[0] in dev_list.keys():
                parser.error ("Invalid VM or device name: %s" % args[0])
            dev = dev_list[args[0]]
            attached_to = block_check_attached(None, dev['device'], backend_xid = dev['xid'])
            if attached_to is None:
                print >> sys.stderr, "WARNING: Device not connected to any VM"
                exit(0)
            block_detach(None, attached_to['devid'], vm_xid=attached_to['xid'])
    else:
        # do_list
        kwargs = {}
        kwargs['system_disks'] = options.system_disks
        for dev in block_list(**kwargs).values():
            attached_to = block_check_attached(None, dev['device'], backend_xid = dev['xid'])
            attached_to_str = ""
            if attached_to:
                attached_to_str = " (attached to '%s' as '%s')" % (attached_to['vm'], attached_to['frontend'])
            size_str = bytes_to_kmg(dev['size'])
            print "%s\t%s %s%s" % (dev['name'], dev['desc'], size_str, attached_to_str)
        exit (0)

main()