#!/usr/bin/python2
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2010  Rafal Wojtczuk  <rafal@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.
#
#
import os
import subprocess
import sys
import fcntl
import shutil
import time

from qubes.qubes import QubesVmCollection
from qubes.qubes import QubesException
from qubes.qubes import QubesDaemonPidfile
from qubes.qubes import QubesDispVmLabels
from qubes.notify import tray_notify,tray_notify_error,tray_notify_init

current_savefile = '/var/run/qubes/current-savefile'
current_dvm_conf = '/var/run/qubes/current-dvm.conf'
current_savefile_vmdir = '/var/lib/qubes/dvmdata/vmdir'

class QfileDaemonDvm:
    def __init__(self, name):
        self.name = name

    def get_disp_templ(self):
        vmdir = os.readlink(current_savefile_vmdir)
        return vmdir.split('/')[-1]
        
    def do_get_dvm(self):
        tray_notify("red", "Starting new DispVM...")

        qvm_collection = QubesVmCollection()
        qvm_collection.lock_db_for_writing()

        tar_process = subprocess.Popen(['tar', '-C', current_savefile_vmdir,
            '-xSUf', os.path.join(current_savefile_vmdir, 'saved-cows.tar')])

        qvm_collection.load()
        print >>sys.stderr, "time=%s, collection loaded" % (str(time.time()))

        vm = qvm_collection.get_vm_by_name(self.name)
        if vm is None:
            sys.stderr.write( 'Domain ' + self.name + ' does not exist ?')
            qvm_collection.unlock_db()
            return None
        label = vm.label
        if len(sys.argv) > 4 and len(sys.argv[4]) > 0:
            assert sys.argv[4] in QubesDispVmLabels.keys(), "Invalid label"
            label = QubesDispVmLabels[sys.argv[4]]
        disp_templ = self.get_disp_templ()
        vm_disptempl = qvm_collection.get_vm_by_name(disp_templ);
        if vm_disptempl is None:
            sys.stderr.write( 'Domain ' + disptempl + ' does not exist ?')
            qvm_collection.unlock_db()
            return None
        dispvm=qvm_collection.add_new_vm('QubesDisposableVm', disp_template=vm_disptempl, label=label)
        print >>sys.stderr, "time=%s, VM created" % (str(time.time()))
        # By default inherit firewall rules from calling VM
        if os.path.exists(vm.firewall_conf):
            disp_firewall_conf = '/var/run/qubes/%s-firewall.xml' % disp_name
            shutil.copy(vm.firewall_conf, disp_firewall_conf)
            dispvm.firewall_conf = disp_firewall_conf
        if len(sys.argv) > 5 and len(sys.argv[5]) > 0:
            assert os.path.exists(sys.argv[5]), "Invalid firewall.conf location"
            dispvm.firewall_conf = sys.argv[5]
        # Wait for tar to finish
        if tar_process.wait() != 0:
            sys.stderr.write('Failed to unpack saved-cows.tar')
            qvm_collection.unlock_db()
            return None
        print >>sys.stderr, "time=%s, VM starting" % (str(time.time()))
        dispvm.start()
        print >>sys.stderr, "time=%s, VM started" % (str(time.time()))
        qvm_collection.save()
        qvm_collection.unlock_db()
        # Reload firewall rules
        print >>sys.stderr, "time=%s, reloading firewall" % (str(time.time()))
        for vm in qvm_collection.values():
            if vm.is_proxyvm() and vm.is_running():
                vm.write_iptables_xenstore_entry()

        return dispvm

    def dvm_setup_ok(self):
        dvmdata_dir = '/var/lib/qubes/dvmdata/'
        if not os.path.isfile(current_savefile):
            return False
        if not os.path.isfile(dvmdata_dir+'default-savefile') or not os.path.isfile(dvmdata_dir+'savefile-root'):
            return False
        dvm_mtime = os.stat(current_savefile).st_mtime
        root_mtime = os.stat(dvmdata_dir+'savefile-root').st_mtime
        if dvm_mtime < root_mtime:
            template_name = os.path.basename(os.path.dirname(os.readlink(dvmdata_dir+'savefile-root')))
            if subprocess.call(["xl", "domid", template_name]) == 0:
                tray_notify("For optimum performance, you should not "
                                  "start DispVM when its template is running.", "red")
            return False       
        return True

    def get_dvm(self):
        if not self.dvm_setup_ok():
            if os.system("/usr/lib/qubes/qubes-update-dispvm-savefile-with-progress.sh >/dev/null </dev/null" ) != 0:
                tray_notify_error("DVM savefile creation failed")
                return None 
        return self.do_get_dvm()

    def remove_disposable_from_qdb(self, name):
        qvm_collection = QubesVmCollection()
        qvm_collection.lock_db_for_writing()
        qvm_collection.load()
        vm = qvm_collection.get_vm_by_name(name)
        if vm is None:
            qvm_collection.unlock_db()
            return False
        qvm_collection.pop(vm.qid)
        qvm_collection.save()
        qvm_collection.unlock_db()

def main():
    global notify_object
    exec_index = sys.argv[1]
    src_vmname = sys.argv[2]
    user = sys.argv[3]
    #accessed directly by get_dvm()
    # sys.argv[4] - override label
    # sys.argv[5] - override firewall

    print >>sys.stderr, "time=%s, qfile-daemon-dvm init" % (str(time.time()))
    tray_notify_init()
    print >>sys.stderr, "time=%s, creating DispVM" % (str(time.time()))
    qfile = QfileDaemonDvm(src_vmname)
    dispvm = qfile.get_dvm()
    if dispvm is not None:
        print >>sys.stderr, "time=%s, starting VM process" % (str(time.time()))
        subprocess.call(['/usr/lib/qubes/qrexec-client', '-d', dispvm.name,
            user+':exec /usr/lib/qubes/qubes-rpc-multiplexer ' + exec_index + " " + src_vmname])
        dispvm.force_shutdown()
        qfile.remove_disposable_from_qdb(dispvm.name)

main()