#!/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.qmemman_client import QMemmanClient
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'

class QfileDaemonDvm:
    def __init__(self, name):
        self.name = name
        
    def do_get_dvm(self):
        qmemman_client = QMemmanClient()
        if not qmemman_client.request_memory(400*1024*1024):
            qmemman_client.close()
            errmsg = 'Not enough memory to create DVM. '
            errmsg +='Terminate some appVM and retry.'
            tray_notify_error(errmsg)
            return None

        tray_notify("Starting new DispVM...", "red")

        qvm_collection = QubesVmCollection()
        qvm_collection.lock_db_for_writing()
        qvm_collection.load()

        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()
            qmemman_client.close()
            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]]
        print >>sys.stderr, "time=%s, starting qubes-restore" % (str(time.time()))
        retcode = subprocess.call(['/usr/lib/qubes/qubes-restore',
            current_savefile,
            current_dvm_conf,
            '-u', str(vm.default_user),
            '-c', label.color,
            '-i', label.icon_path,
            '-l', str(label.index)])
        qmemman_client.close()
        if retcode != 0:
            tray_notify_error('DisposableVM creation failed, see qubes-restore.log')
            qvm_collection.unlock_db()
            return None
        f = open('/var/run/qubes/dispVM.xid', 'r');
        disp_xid = f.readline().rstrip('\n')
        disp_name = f.readline().rstrip('\n')
        disptempl = f.readline().rstrip('\n')
        f.close()
        print >>sys.stderr, "time=%s, adding to qubes.xml" % (str(time.time()))
        vm_disptempl = qvm_collection.get_vm_by_name(disptempl);
        if vm_disptempl is None:
            sys.stderr.write( 'Domain ' + disptempl + ' does not exist ?')
            qvm_collection.unlock_db()
            return None
        dispid=int(disp_name[4:])
        dispvm=qvm_collection.add_new_disposablevm(disp_name, vm_disptempl.template, label=label, dispid=dispid, netvm=vm_disptempl.netvm)
        # 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]
        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 disp_name

    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)
    lockf = open("/var/run/qubes/qfile-daemon-dvm.lock", 'a')
    fcntl.fcntl(lockf, fcntl.F_SETFD, fcntl.FD_CLOEXEC)
    fcntl.flock(lockf, fcntl.LOCK_EX)
    dispname = qfile.get_dvm()
    lockf.close()
    if dispname is not None:
        print >>sys.stderr, "time=%s, starting VM process" % (str(time.time()))
        subprocess.call(['/usr/lib/qubes/qrexec-client', '-d', dispname,
            user+':exec /usr/lib/qubes/qubes-rpc-multiplexer ' + exec_index + " " + src_vmname])
        subprocess.call(['/usr/sbin/xl', 'destroy', dispname])
        qfile.remove_disposable_from_qdb(dispname)

main()