# encoding=utf-8
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2016 Marek Marczykowski-Górecki
# <marmarek@invisiblethingslab.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser 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.
'''qvm-firewall tool'''
import argparse
import datetime
import sys
import itertools
import qubesadmin.exc
import qubesadmin.firewall
import qubesadmin.tools
class RuleAction(argparse.Action):
# pylint: disable=too-few-public-methods
'''Parser action for a single firewall rule. It accept syntax:
- <action> [<dsthost> [<proto> [<dstports>|<icmptype>]]]
- action=<action> [specialtarget=dns] [dsthost=<dsthost>]
[proto=<proto>] [dstports=<dstports>] [icmptype=<icmptype>]
Or a mix of them.
'''
def __call__(self, _parser, namespace, values, option_string=None):
if not values:
setattr(namespace, self.dest, None)
return
assumed_order = ['action', 'dsthost', 'proto', 'dstports', 'icmptype']
allowed_opts = assumed_order + ['specialtarget', 'comment', 'expire']
kwargs = {}
for opt in values:
opt_elements = opt.split('=')
if len(opt_elements) == 2:
key, value = opt_elements
elif len(opt_elements) == 1:
key, value = assumed_order[0], opt
else:
raise argparse.ArgumentError(None,
'invalid rule description: {}'.format(opt))
if key in ['dst4', 'dst6']:
key = 'dsthost'
if key not in allowed_opts:
raise argparse.ArgumentError(None,
'Invalid rule element: {}'.format(opt))
if key == 'expire' and value.startswith('+'):
value = (datetime.datetime.now() +
datetime.timedelta(seconds=int(value[1:]))).\
strftime('%s')
kwargs[key] = value
if key in assumed_order:
assumed_order.remove(key)
if key == 'proto' and value in ['tcp', 'udp']:
assumed_order.remove('icmptype')
elif key == 'proto' and value in ['icmp']:
assumed_order.remove('dstports')
rule = qubesadmin.firewall.Rule(None, **kwargs)
setattr(namespace, self.dest, rule)
epilog = """
Rules can be given as positional arguments:
<action> [<dsthost> [<proto> [<dstports>|<icmptype>]]]
And as keyword arguments:
action=<action> [specialtarget=dns] [dsthost=<dsthost>]
[proto=<proto>] [dstports=<dstports>] [icmptype=<icmptype>]
[expire=<expire>]
Both formats, positional and keyword arguments, can be used
interchangeably.
Available matches:
action: accept or drop
dst4 synonym for dsthost
dst6 synonym for dsthost
dsthost IP, network or hostname
(e.g. 10.5.3.2, 192.168.0.0/16,
www.example.com, fd00::/8)
dstports port or port range
(e.g. 443 or 1200-1400)
icmptype icmp type number (e.g. 8 for echo requests)
proto icmp, tcp or udp
specialtarget only the value dns is currently supported,
it matches the configured dns servers of
a VM
expire the rule is automatically removed at the time given as
seconds since 1/1/1970, or +seconds (e.g. +300 for a rule
to expire in 5 minutes)
"""
parser = qubesadmin.tools.QubesArgumentParser(vmname_nargs=1, epilog=epilog,
formatter_class=argparse.RawTextHelpFormatter)
action = parser.add_subparsers(dest='command', help='action to perform')
action_add = action.add_parser('add', help='add rule')
action_add.add_argument('--before', type=int, default=None,
help='Add rule before rule with given number instead at the end')
action_add.add_argument('rule', metavar='match', nargs='+', action=RuleAction,
help='rule description')
action_del = action.add_parser('del', help='remove rule')
action_del.add_argument('--rule-no', dest='rule_no', type=int,
action='store', help='rule number')
action_del.add_argument('rule', metavar='match', nargs='*', action=RuleAction,
help='rule to be removed')
action_list = action.add_parser('list', help='list rules')
action_reset = action.add_parser(
'reset',
help='remove all firewall rules and reset to default '
'(accept all connections)')
parser.add_argument('--reload', '-r', action='store_true',
help='force reload of rules even when unchanged')
parser.add_argument('--raw', action='store_true',
help='output rules as raw strings, instead of nice table')
def rules_list_table(vm):
'''Print rules to stdout in human-readable form (table)
:param vm: VM object
:return: None
'''
header = ['NO', 'ACTION', 'HOST', 'PROTOCOL', 'PORT(S)',
'SPECIAL TARGET', 'ICMP TYPE', 'EXPIRE', 'COMMENT']
rows = []
for (rule, rule_no) in zip(vm.firewall.rules, itertools.count()):
row = [x.pretty_value if x is not None else '-' for x in [
rule.action,
rule.dsthost,
rule.proto,
rule.dstports,
rule.specialtarget,
rule.icmptype,
rule.expire,
rule.comment,
]]
rows.append([str(rule_no)] + row)
qubesadmin.tools.print_table([header] + rows)
def rules_list_raw(vm):
'''Print rules in machine-readable form (as specified in Admin API)
:param vm: VM object
:return: None
'''
for rule in vm.firewall.rules:
sys.stdout.write(rule.rule + '\n')
def rules_add(vm, args):
'''Add a rule defined by args.rule'''
if args.before is not None:
vm.firewall.rules.insert(args.before, args.rule)
else:
vm.firewall.rules.append(args.rule)
vm.firewall.save_rules()
def rules_del(vm, args):
'''Delete a rule according to args.rule/args.rule_no'''
if args.rule_no is not None:
vm.firewall.rules.pop(args.rule_no)
else:
vm.firewall.rules.remove(args.rule)
vm.firewall.save_rules()
def main(args=None, app=None):
'''Main routine of :program:`qvm-firewall`.'''
try:
args = parser.parse_args(args, app=app)
vm = args.domains[0]
if args.command == 'add':
rules_add(vm, args)
elif args.command == 'del':
rules_del(vm, args)
elif args.command == 'reset':
vm.firewall.rules.clear()
vm.firewall.rules.append(qubesadmin.firewall.Rule('action=accept'))
vm.firewall.save_rules()
else:
if args.raw:
rules_list_raw(vm)
else:
rules_list_table(vm)
if args.reload:
vm.firewall.reload()
except qubesadmin.exc.QubesException as e:
parser.print_error(str(e))
return 1
return 0
if __name__ == '__main__':
sys.exit(main())