core-admin/qvm-tools/qvm-firewall
2013-03-16 19:56:51 +01:00

334 lines
11 KiB
Python
Executable File

#!/usr/bin/python2
#
# The Qubes OS Project, http://www.qubes-os.org
#
# Copyright (C) 2012 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
from optparse import OptionParser;
import subprocess
import sys
import re
import os
services = list()
def load_services():
global services
services = list()
pattern = re.compile("(?P<name>[a-z][a-z0-9-]+)\s+(?P<port>[0-9]+)/(?P<protocol>[a-z]+)", re.IGNORECASE)
f = open('/etc/services', 'r')
for line in f:
match = pattern.match(line)
if match is not None:
service = match.groupdict()
services.append( (service["name"], int(service["port"]), service["protocol"]) )
f.close()
def get_service_name(port):
for service in services:
if service[1] == port:
return service[0]
return str(port)
def get_service_port(name):
for service in services:
if service[0] == name:
return int(service[1])
return None
def parse_rule(args):
if len(args) < 2:
print >>sys.stderr, "ERROR: Rule must have at least address and protocol"
return None
address = args[0]
netmask = 32
proto = args[1]
port = args[2] if len(args) > 2 else None
port_end = None
unmask = address.split("/", 1)
if len(unmask) == 2:
address = unmask[0]
netmask = unmask[1]
if netmask.isdigit():
if re.match("^([0-9]{1,3}\.){3}[0-9]{1,3}$", address) is None:
print >>sys.stderr, "ERROR: Only IP is allowed when specyfying netmask"
return None
if netmask != "":
netmask = int(unmask[1])
if netmask < 0 or netmask > 32:
print >>sys.stderr, "ERROR: Invalid netmask"
return None
else:
print >>sys.stderr, "ERROR: Invalid netmask"
return None
if address[-1:] == ".":
address = address[:-1]
allowed = re.compile("(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
if not all(allowed.match(x) for x in address.split(".")):
print >>sys.stderr, "ERROR: Invalid hostname"
return None
proto_split = proto.split('/', 1)
if len(proto_split) == 2:
proto = proto_split[0]
port = proto_split[1]
if proto not in ['tcp', 'udp', 'any']:
print >>sys.stderr, "ERROR: Protocol must be one of: 'tcp', 'udp', 'any'"
return None
if proto != "any" and port is None:
print >>sys.stderr, "ERROR: Port required for protocol %s" % args[1]
return None
if port is not None:
port_range = port.split('-', 1)
if len(port_range) == 2:
port = port_range[0]
port_end = port_range[1]
if get_service_port(port):
port = get_service_port(port)
elif not port.isdigit():
print >>sys.stderr, "ERROR: Invalid port/service name '%s'" % port
return None
else:
port = int(port)
if port_end is not None and not port_end.isdigit():
print >>sys.stderr, "ERROR: Invalid port '%s'" % port_end
return None
if port_end is not None:
port_end = int(port_end)
rule = {}
rule['address'] = address
rule['netmask'] = netmask
rule['proto'] = proto
rule['portBegin'] = port
rule['portEnd'] = port_end
return rule
def list_rules(rules):
fields = [ "num", "address", "proto", "port(s)" ]
rules_to_display = list()
counter = 1
for rule in rules:
parsed_rule = {
'num': "{0:>2}".format(counter),
'address': rule['address'] + ('/' + str(rule['netmask']) if rule['netmask'] < 32 else ""),
'proto': rule['proto'],
'port(s)': '',
}
if rule['proto'] in ['tcp', 'udp']:
parsed_rule['port(s)'] = str(rule['portBegin']) + \
('-' + str(rule['portEnd']) if rule['portEnd'] is not None else '')
if rule['portBegin'] is not None and rule['portEnd'] is None:
parsed_rule['port(s)'] = get_service_name(rule['portBegin'])
rules_to_display.append(parsed_rule)
counter += 1
fields_width = {}
for f in fields:
fields_width[f] = len(f)
for r in rules_to_display:
if len(r[f]) > fields_width[f]:
fields_width[f] = len(r[f])
# Display the header
s = ""
for f in fields:
fmt="{{0:-^{0}}}-+".format(fields_width[f] + 1)
s += fmt.format('-')
print s
s = ""
for f in fields:
fmt=" {{0:^{0}}} |".format(fields_width[f])
s += fmt.format(f)
print s
s = ""
for f in fields:
fmt="{{0:-^{0}}}-+".format(fields_width[f] + 1)
s += fmt.format('-')
print s
# And the content
for r in rules_to_display:
s = ""
for f in fields:
fmt=" {{0:<{0}}} |".format(fields_width[f])
s += fmt.format(r[f])
print s
def display_firewall(conf):
print "Firewall policy: %s" % (
"ALLOW all traffic except" if conf['allow'] else "DENY all traffic except")
print "ICMP: %s" % ("ALLOW" if conf['allowIcmp'] else 'DENY')
print "DNS: %s" % ("ALLOW" if conf['allowDns'] else 'DENY')
print "Qubes yum proxy: %s" % ("ALLOW" if conf['allowYumProxy'] else 'DENY')
list_rules(conf['rules'])
def add_rule(conf, args):
rule = parse_rule(args)
if rule is None:
return False
conf['rules'].append(rule)
return True
def del_rule(conf, args):
if len(args) == 1 and args[0].isdigit():
rulenum = int(args[0])
if rulenum < 1 or rulenum > len(conf['rules']):
print >>sys.stderr, "ERROR: Rule number out of range"
return False
conf['rules'].pop(rulenum-1)
else:
rule = parse_rule(args)
#print "PARSED: %s" % str(rule)
#print "ALL: %s" % str(conf['rules'])
if rule is None:
return False
try:
conf['rules'].remove(rule)
except ValueError:
print >>sys.stderr, "ERROR: Rule not found"
return False
return True
def allow_deny_value(s):
value = None
if s == "allow":
value = True
elif s == "deny":
value = False
else:
print >>sys.stderr, 'ERROR: Only "allow" or "deny" allowed'
exit(1)
return value
def main():
usage = "usage: %prog [-n] <vm-name> [action] [rule spec]\n"
usage += " rule specification can be one of:\n"
usage += " address|hostname[/netmask] tcp|udp port[-port]\n"
usage += " address|hostname[/netmask] tcp|udp service_name\n"
usage += " address|hostname[/netmask] any\n"
parser = OptionParser (usage)
parser.add_option ("-l", "--list", dest="do_list", action="store_true", default=True,
help="List firewall settings (default action)")
parser.add_option ("-a", "--add", dest="do_add", action="store_true", default=False,
help="Add rule")
parser.add_option ("-d", "--del", dest="do_del", action="store_true", default=False,
help="Remove rule (given by number or by rule spec)")
parser.add_option ("-P", "--policy", dest="set_policy", action="store", default=None,
help="Set firewall policy (allow/deny)")
parser.add_option ("-i", "--icmp", dest="set_icmp", action="store", default=None,
help="Set ICMP access (allow/deny)")
parser.add_option ("-D", "--dns", dest="set_dns", action="store", default=None,
help="Set DNS access (allow/deny)")
parser.add_option ("-Y", "--yum-proxy", dest="set_yum_proxy", action="store", default=None,
help="Set access to Qubes yum proxy (allow/deny)")
parser.add_option ("-n", "--numeric", dest="numeric", action="store_true", default=False,
help="Display port numbers instead of services (makes sense only with --list)")
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 (len (args) < 1):
parser.error ("You must specify VM name!")
vmname = args[0]
args = args[1:]
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_add or options.do_del or options.set_policy or options.set_icmp or options.set_dns or options.set_yum_proxy:
options.do_list = False
qvm_collection = QubesVmCollection()
if options.do_list:
qvm_collection.lock_db_for_reading()
qvm_collection.load()
qvm_collection.unlock_db()
else:
qvm_collection.lock_db_for_writing()
qvm_collection.load()
vm = qvm_collection.get_vm_by_name(vmname)
if vm is None:
print >> sys.stderr, "A VM with the name '{0}' does not exist in the system.".format(vmname)
exit(1)
changed = False
conf = vm.get_firewall_conf()
if options.set_policy:
conf['allow'] = allow_deny_value(options.set_policy)
changed = True
if options.set_icmp:
conf['allowIcmp'] = allow_deny_value(options.set_icmp)
changed = True
if options.set_dns:
conf['allowDns'] = allow_deny_value(options.set_dns)
changed = True
if options.set_yum_proxy:
conf['allowYumProxy'] = allow_deny_value(options.set_yum_proxy)
changed = True
if options.do_add:
load_services()
changed = add_rule(conf, args)
elif options.do_del:
load_services()
changed = del_rule(conf, args)
elif options.do_list:
if not options.numeric:
load_services()
if not vm.has_firewall():
print "INFO: This VM has no firewall rules set, below defaults are listed"
display_firewall(conf)
if changed:
vm.write_firewall_conf(conf)
if vm.is_running():
if vm.netvm is not None and vm.netvm.is_proxyvm():
vm.netvm.write_iptables_xenstore_entry()
qvm_collection.save()
if not options.do_list:
qvm_collection.unlock_db()
main()