Source code for qubesadmin.tools.qvm_firewall

# encoding=utf-8
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2016 Marek Marczykowski-Górecki
#                               <[email protected]>
#
# 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


[docs]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') 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')
[docs]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)
[docs]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')
[docs]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()
[docs]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()
[docs]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) 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())