[feature] add install/uninstall command for helpers

1 files changed, 0 insertions, 971 deletions

diff --git a/src/leap/bitmask/vpn/fw/bitmask-root b/src/leap/bitmask/vpn/fw/bitmask-root
deleted file mode 100755
index 80ac12e..0000000
--- a/src/leap/bitmask/vpn/fw/bitmask-root
+++ /dev/null
@@ -1,971 +0,0 @@
-#!/usr/bin/python2.7
-# -*- coding: utf-8 -*-
-#
-# Copyright (C) 2014 LEAP
-#
-# 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 3 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, see <http://www.gnu.org/licenses/>.
-#
-"""
-This is a privileged helper script for safely running certain commands as root.
-It should only be called by the Bitmask application.
-
-USAGE:
-  bitmask-root firewall stop
-  bitmask-root firewall start [restart] GATEWAY1 GATEWAY2 ...
-  bitmask-root openvpn stop
-  bitmask-root openvpn start CONFIG1 CONFIG1 ...
-  bitmask-root fw-email stop
-  bitmask-root fw-email start uid
-
-All actions return exit code 0 for success, non-zero otherwise.
-
-The `openvpn start` action is special: it calls exec on openvpn and replaces
-the current process. If the `restart` parameter is passed, the firewall will
-not be teared down in the case of an error during launch.
-"""
-# TODO should be tested with python3, which can be the default on some distro.
-from __future__ import print_function
-import os
-import re
-import signal
-import socket
-import syslog
-import subprocess
-import sys
-import traceback
-
-cmdcheck = subprocess.check_output
-
-#
-# CONSTANTS
-#
-
-
-def get_no_group_name():
-    """
-    Return the right group name to use for the current OS.
-    Examples:
-        - Ubuntu: nogroup
-        - Arch: nobody
-
-    :rtype: str or None
-    """
-    import grp
-    try:
-        grp.getgrnam('nobody')
-        return 'nobody'
-    except KeyError:
-        try:
-            grp.getgrnam('nogroup')
-            return 'nogroup'
-        except KeyError:
-            return None
-
-
-VERSION = "6"
-SCRIPT = "bitmask-root"
-NAMESERVER = "10.42.0.1"
-BITMASK_CHAIN = "bitmask"
-BITMASK_CHAIN_NAT_OUT = "bitmask"
-BITMASK_CHAIN_NAT_POST = "bitmask_postrouting"
-BITMASK_CHAIN_EMAIL = "bitmask_email"
-BITMASK_CHAIN_EMAIL_OUT = "bitmask_email_output"
-LOCAL_INTERFACE = "lo"
-IMAP_PORT = "1984"
-SMTP_PORT = "2013"
-
-IP = "/sbin/ip"
-IPTABLES = "/sbin/iptables"
-IP6TABLES = "/sbin/ip6tables"
-
-OPENVPN_USER = "nobody"
-OPENVPN_GROUP = get_no_group_name()
-LEAPOPENVPN = "LEAPOPENVPN"
-OPENVPN_SYSTEM_BIN = "/usr/sbin/openvpn"  # Debian location
-OPENVPN_LEAP_BIN = "/usr/local/sbin/leap-openvpn"  # installed by bundle
-
-FIXED_FLAGS = [
-    "--setenv", "LEAPOPENVPN", "1",
-    "--nobind",
-    "--client",
-    "--dev", "tun",
-    "--tls-client",
-    "--remote-cert-tls", "server",
-    "--management-signal",
-    "--script-security", "1",
-    "--user", "nobody",
-    "--remap-usr1", "SIGTERM",
-]
-
-if OPENVPN_GROUP is not None:
-    FIXED_FLAGS.extend(["--group", OPENVPN_GROUP])
-
-ALLOWED_FLAGS = {
-    "--remote": ["IP", "NUMBER", "PROTO"],
-    "--tls-cipher": ["CIPHER"],
-    "--cipher": ["CIPHER"],
-    "--auth": ["CIPHER"],
-    "--management": ["DIR", "UNIXSOCKET"],
-    "--management-client-user": ["USER"],
-    "--cert": ["FILE"],
-    "--key": ["FILE"],
-    "--ca": ["FILE"],
-    "--fragment": ["NUMBER"]
-}
-
-PARAM_FORMATS = {
-    "NUMBER": lambda s: re.match("^\d+$", s),
-    "PROTO": lambda s: re.match("^(tcp|udp)$", s),
-    "IP": lambda s: is_valid_address(s),
-    "CIPHER": lambda s: re.match("^[A-Z0-9-]+$", s),
-    "USER": lambda s: re.match(
-        "^[a-zA-Z0-9_\.\@][a-zA-Z0-9_\-\.\@]*\$?$", s),  # IEEE Std 1003.1-2001
-    "FILE": lambda s: os.path.isfile(s),
-    "DIR": lambda s: os.path.isdir(os.path.split(s)[0]),
-    "UNIXSOCKET": lambda s: s == "unix",
-    "UID": lambda s: re.match("^[a-zA-Z0-9]+$", s)
-}
-
-
-DEBUG = os.getenv("DEBUG")
-TEST = os.getenv("TEST")
-
-if DEBUG:
-    import logging
-    formatter = logging.Formatter(
-        "%(asctime)s - %(name)s - %(levelname)s - %(message)s")
-    ch = logging.StreamHandler()
-    ch.setLevel(logging.DEBUG)
-    ch.setFormatter(formatter)
-    logger = logging.getLogger(__name__)
-    logger.setLevel(logging.DEBUG)
-    logger.addHandler(ch)
-
-syslog.openlog(SCRIPT)
-
-#
-# UTILITY
-#
-
-
-def is_valid_address(value):
-    """
-    Validate that the passed ip is a valid IP address.
-
-    :param value: the value to be validated
-    :type value: str
-    :rtype: bool
-    """
-    try:
-        socket.inet_aton(value)
-        return True
-    except Exception:
-        log("%s: ERROR: MALFORMED IP: %s!" % (SCRIPT, value))
-        return False
-
-
-def split_list(_list, regex):
-    """
-    Split a list based on a regex:
-    e.g. split_list(["xx", "yy", "x1", "zz"], "^x") => [["xx", "yy"], ["x1",
-    "zz"]]
-
-    :param _list: the list to be split.
-    :type _list: list
-    :param regex: the regex expression to filter with.
-    :type regex: str
-
-    :rtype: list
-    """
-    if not hasattr(regex, "match"):
-        regex = re.compile(regex)
-    result = []
-    i = 0
-    if not _list:
-        return result
-    while True:
-        if regex.match(_list[i]):
-            result.append([])
-            while True:
-                result[-1].append(_list[i])
-                i += 1
-                if i >= len(_list) or regex.match(_list[i]):
-                    break
-        else:
-            i += 1
-        if i >= len(_list):
-            break
-    return result
-
-
-def get_process_list():
-    """
-    Get a process list by reading `/proc` filesystem.
-
-    :return: a list of tuples, each containing pid and command string.
-    :rtype: tuple if lists
-    """
-    res = []
-    pids = [pid for pid in os.listdir('/proc') if pid.isdigit()]
-
-    for pid in pids:
-        try:
-            res.append((pid, open(
-                os.path.join(
-                    '/proc', pid, 'cmdline'), 'rb').read()))
-        except IOError:  # proc has already terminated
-            continue
-    return filter(None, res)
-
-
-def run(command, *args, **options):
-    """
-    Run an external command.
-
-    Options:
-
-      `check`: If True, check the command's output. bail if non-zero. (the
-               default is true unless detach or input is true)
-      `exitcode`: like `check`, but return exitcode instead of bailing.
-      `detach`: If True, run in detached process.
-      `input`: If True, open command for writing stream to, returning the Popen
-               object.
-      `throw`: If True, raise an exception if there is an error instead
-               of bailing.
-    """
-    parts = [command]
-    parts.extend(args)
-    debug("%s run: %s " % (SCRIPT, " ".join(parts)))
-
-    _check = options.get("check", True)
-    _detach = options.get("detach", False)
-    _input = options.get("input", False)
-    _exitcode = options.get("exitcode", False)
-    _throw = options.get("throw", False)
-
-    if not (_check or _throw) or _detach or _input:
-        if _input:
-            return subprocess.Popen(parts, stdin=subprocess.PIPE)
-        else:
-            subprocess.Popen(parts)
-            return None
-    else:
-        try:
-            devnull = open('/dev/null', 'w')
-            subprocess.check_call(parts, stdout=devnull, stderr=devnull)
-            return 0
-        except subprocess.CalledProcessError as exc:
-            if _exitcode:
-                if exc.returncode != 1:
-                    # 0 or 1 is to be expected, but anything else
-                    # should be logged.
-                    debug("ERROR: Could not run %s: %s" %
-                          (exc.cmd, exc.output), exception=exc)
-                return exc.returncode
-            elif _throw:
-                raise exc
-            else:
-                bail("ERROR: Could not run %s: %s" % (exc.cmd, exc.output),
-                     exception=exc)
-
-
-def log(msg=None, exception=None, priority=syslog.LOG_INFO):
-    """
-    print and log warning message or exception.
-
-    :param msg: optional error message.
-    :type msg: str
-    :param msg: optional exception.
-    :type msg: Exception
-    :param msg: syslog level
-    :type msg: one of LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR,
-               LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG
-    """
-    if msg is not None:
-        print("%s: %s" % (SCRIPT, msg))
-        syslog.syslog(priority, msg)
-    if exception is not None:
-        if TEST or DEBUG:
-            traceback.print_exc()
-        syslog.syslog(priority, traceback.format_exc())
-
-
-def debug(msg=None, exception=None):
-    """
-    Just like log, but is skipped unless DEBUG. Use syslog.LOG_INFO
-    even for debug messages (we don't want to miss them).
-    """
-    if TEST or DEBUG:
-        log(msg, exception)
-
-
-def bail(msg=None, exception=None):
-    """
-    abnormal exit. like log(), but exits with error status code.
-    """
-    log(msg, exception)
-    exit(1)
-
-#
-# OPENVPN
-#
-
-
-def get_openvpn_bin():
-    """
-    Return the path for either the system openvpn or the one the
-    bundle has put there.
-    """
-    if os.path.isfile(OPENVPN_SYSTEM_BIN):
-        return OPENVPN_SYSTEM_BIN
-
-    # the bundle option should be removed from the debian package.
-    if os.path.isfile(OPENVPN_LEAP_BIN):
-        return OPENVPN_LEAP_BIN
-
-
-def parse_openvpn_flags(args):
-    """
-    Take argument list from the command line and parse it, only allowing some
-    configuration flags.
-
-    :type args: list
-    """
-    result = []
-    try:
-        for flag in split_list(args, "^--"):
-            flag_name = flag[0]
-            if flag_name in ALLOWED_FLAGS:
-                result.append(flag_name)
-                required_params = ALLOWED_FLAGS[flag_name]
-                if required_params:
-                    flag_params = flag[1:]
-                    if len(flag_params) != len(required_params):
-                        log("%s: ERROR: not enough params for %s" %
-                            (SCRIPT, flag_name))
-                        return None
-                    for param, param_type in zip(flag_params, required_params):
-                        if PARAM_FORMATS[param_type](param):
-                            result.append(param)
-                        else:
-                            log("%s: ERROR: Bad argument %s" %
-                                (SCRIPT, param))
-                            return None
-            else:
-                log("WARNING: unrecognized openvpn flag %s" % flag_name)
-        return result
-    except Exception as exc:
-        log("%s: ERROR PARSING FLAGS: %s" % (SCRIPT, exc))
-        if DEBUG:
-            logger.exception(exc)
-        return None
-
-
-def openvpn_start(args):
-    """
-    Launch openvpn, sanitizing input, and replacing the current process with
-    the openvpn process.
-
-    :param args: arguments to be passed to openvpn
-    :type args: list
-    """
-    openvpn_flags = parse_openvpn_flags(args)
-    if openvpn_flags:
-        OPENVPN = get_openvpn_bin()
-        flags = [OPENVPN] + FIXED_FLAGS + openvpn_flags
-        if DEBUG:
-            log("%s: running openvpn with flags:" % (SCRIPT,))
-            log(flags)
-        # note: first argument to command is ignored, but customarily set to
-        # the command.
-        os.execv(OPENVPN, flags)
-    else:
-        bail('ERROR: could not parse openvpn options')
-
-
-def openvpn_stop(args):
-    """
-    Stop the openvpn that has likely been launched by bitmask.
-
-    :param args: arguments to openvpn
-    :type args: list
-    """
-    plist = get_process_list()
-    OPENVPN_BIN = get_openvpn_bin()
-    found_leap_openvpn = filter(
-        lambda (p, s): s.startswith(OPENVPN_BIN) and LEAPOPENVPN in s,
-        plist)
-
-    if found_leap_openvpn:
-        pid = found_leap_openvpn[0][0]
-        os.kill(int(pid), signal.SIGTERM)
-
-#
-# FIREWALL
-#
-
-
-def get_gateways(gateways):
-    """
-    Filter a passed sequence of gateways, returning only the valid ones.
-
-    :param gateways: a sequence of gateways to filter.
-    :type gateways: iterable
-    :rtype: iterable
-    """
-    result = filter(is_valid_address, gateways)
-    if not result:
-        bail("ERROR: No valid gateways specified")
-    else:
-        return result
-
-
-def get_default_device():
-    """
-    Retrieve the current default network device.
-
-    :rtype: str
-    """
-    routes = subprocess.check_output([IP, "route", "show"])
-    match = re.search("^default .*dev ([^\s]*) .*$", routes, flags=re.M)
-    if match and match.groups():
-        return match.group(1)
-    else:
-        bail("Could not find default device")
-
-
-def get_local_network_ipv4(device):
-    """
-    Get the local ipv4 addres for a given device.
-
-    :param device:
-    :type device: str
-    """
-    addresses = cmdcheck([IP, "-o", "address", "show", "dev", device])
-    match = re.search("^.*inet ([^ ]*) .*$", addresses, flags=re.M)
-    if match and match.groups():
-        return match.group(1)
-    else:
-        return None
-
-
-def get_local_network_ipv6(device):
-    """
-    Get the local ipv6 addres for a given device.
-
-    :param device:
-    :type device: str
-    """
-    addresses = cmdcheck([IP, "-o", "address", "show", "dev", device])
-    match = re.search("^.*inet6 ([^ ]*) .*$", addresses, flags=re.M)
-    if match and match.groups():
-        return match.group(1)
-    else:
-        return None
-
-
-def run_iptable_with_check(cmd, *args, **options):
-    """
-    Run an iptables command checking to see if it should:
-      for --append: run only if rule does not already exist.
-      for --insert: run only if rule does not already exist.
-      for --delete: run only if rule does exist.
-    other commands are run normally.
-    """
-    if "--insert" in args:
-        check_args = [arg.replace("--insert", "--check") for arg in args]
-        check_code = run(cmd, *check_args, exitcode=True)
-        if check_code != 0:
-            run(cmd, *args, **options)
-    elif "--append" in args:
-        check_args = [arg.replace("--append", "--check") for arg in args]
-        check_code = run(cmd, *check_args, exitcode=True)
-        if check_code != 0:
-            run(cmd, *args, **options)
-    elif "--delete" in args:
-        check_args = [arg.replace("--delete", "--check") for arg in args]
-        check_code = run(cmd, *check_args, exitcode=True)
-        if check_code == 0:
-            run(cmd, *args, **options)
-    else:
-        run(cmd, *args, **options)
-
-
-def iptables(*args, **options):
-    """
-    Run iptables4 and iptables6.
-    """
-    ip4tables(*args, **options)
-    ip6tables(*args, **options)
-
-
-def ip4tables(*args, **options):
-    """
-    Run iptables4 with checks.
-    """
-    run_iptable_with_check(IPTABLES, *args, **options)
-
-
-def ip6tables(*args, **options):
-    """
-    Run iptables6 with checks.
-    """
-    run_iptable_with_check(IP6TABLES, *args, **options)
-
-#
-# NOTE: these tests to see if a chain exists might incorrectly return false.
-# This happens when there is an error in calling `iptables --list bitmask`.
-#
-# For this reason, when stopping the firewall, we do not trust the
-# output of ipvx_chain_exists() but instead always attempt to delete
-# the chain.
-#
-
-
-def ipv4_chain_exists(chain, table=None):
-    """
-    Check if a given chain exists. Only returns true if it actually exists,
-    but might return false if it exists and iptables failed to run.
-
-    :param chain: the chain to check against
-    :type chain: str
-    :rtype: bool
-    """
-    if table is not None:
-        code = run(IPTABLES, "-t", table,
-                   "--list", chain, "--numeric", exitcode=True)
-    else:
-        code = run(IPTABLES, "--list", chain, "--numeric", exitcode=True)
-    if code == 0:
-        return True
-    elif code == 1:
-        return False
-    else:
-        log("ERROR: Could not determine state of iptable chain")
-        return False
-
-
-def ipv6_chain_exists(chain):
-    """
-    see ipv4_chain_exists()
-
-    :param chain: the chain to check against
-    :type chain: str
-    :rtype: bool
-    """
-    code = run(IP6TABLES, "--list", chain, "--numeric", exitcode=True)
-    if code == 0:
-        return True
-    elif code == 1:
-        return False
-    else:
-        log("ERROR: Could not determine state of iptable chain")
-        return False
-
-
-def enable_ip_forwarding():
-    """
-    ip_fowarding must be enabled for the firewall to work.
-    """
-    with open('/proc/sys/net/ipv4/ip_forward', 'w') as f:
-        f.write('1\n')
-
-
-def firewall_start(args):
-    """
-    Bring up the firewall.
-
-    :param args: list of gateways, to be sanitized.
-    :type args: list
-    """
-    default_device = get_default_device()
-    local_network_ipv4 = get_local_network_ipv4(default_device)
-    local_network_ipv6 = get_local_network_ipv6(default_device)
-    gateways = get_gateways(args)
-
-    # add custom chain "bitmask" to front of OUTPUT chain for both
-    # the 'filter' and the 'nat' tables.
-    if not ipv4_chain_exists(BITMASK_CHAIN):
-        ip4tables("--new-chain", BITMASK_CHAIN)
-    if not ipv4_chain_exists(BITMASK_CHAIN_NAT_OUT, 'nat'):
-        ip4tables("--table", "nat", "--new-chain", BITMASK_CHAIN_NAT_OUT)
-    if not ipv4_chain_exists(BITMASK_CHAIN_NAT_POST, 'nat'):
-        ip4tables("--table", "nat", "--new-chain", BITMASK_CHAIN_NAT_POST)
-    if not ipv6_chain_exists(BITMASK_CHAIN):
-        ip6tables("--new-chain", BITMASK_CHAIN)
-    ip4tables("--table", "nat", "--insert", "OUTPUT",
-              "--jump", BITMASK_CHAIN_NAT_OUT)
-    ip4tables("--table", "nat", "--insert", "POSTROUTING",
-              "--jump", BITMASK_CHAIN_NAT_POST)
-    iptables("--insert", "OUTPUT", "--jump", BITMASK_CHAIN)
-
-    # route all ipv4 DNS over VPN
-    # (note: NAT does not work with ipv6 until kernel 3.7)
-    enable_ip_forwarding()
-    # allow dns to localhost
-    ip4tables("-t", "nat", "--append", BITMASK_CHAIN, "--protocol", "udp",
-              "--dest", "127.0.1.1,127.0.0.1", "--dport", "53",
-              "--jump", "ACCEPT")
-    # rewrite all outgoing packets to use VPN DNS server
-    # (DNS does sometimes use TCP!)
-    ip4tables("-t", "nat", "--append", BITMASK_CHAIN_NAT_OUT, "-p", "udp",
-              "--dport", "53", "--jump", "DNAT", "--to", NAMESERVER+":53")
-    ip4tables("-t", "nat", "--append", BITMASK_CHAIN_NAT_OUT, "-p", "tcp",
-              "--dport", "53", "--jump", "DNAT", "--to", NAMESERVER+":53")
-    # enable masquerading, so that DNS packets rewritten by DNAT will
-    # have the correct source IPs
-    ip4tables("-t", "nat", "--append", BITMASK_CHAIN_NAT_POST,
-              "--protocol", "udp", "--dport", "53", "--jump", "MASQUERADE")
-    ip4tables("-t", "nat", "--append", BITMASK_CHAIN_NAT_POST,
-              "--protocol", "tcp", "--dport", "53", "--jump", "MASQUERADE")
-
-    # allow local network traffic
-    if local_network_ipv4:
-        # allow local network destinations
-        ip4tables("--append", BITMASK_CHAIN,
-                  "--destination", local_network_ipv4, "-o", default_device,
-                  "--jump", "ACCEPT")
-        # allow local network sources for DNS
-        # (required to allow local network DNS that gets rewritten by NAT
-        #  to get passed through so that MASQUERADE can set correct source IP)
-        ip4tables("--append", BITMASK_CHAIN,
-                  "--source", local_network_ipv4, "-o", default_device,
-                  "-p", "udp", "--dport", "53", "--jump", "ACCEPT")
-        ip4tables("--append", BITMASK_CHAIN,
-                  "--source", local_network_ipv4, "-o", default_device,
-                  "-p", "tcp", "--dport", "53", "--jump", "ACCEPT")
-        # allow multicast Simple Service Discovery Protocol
-        ip4tables("--append", BITMASK_CHAIN,
-                  "--protocol", "udp",
-                  "--destination", "239.255.255.250", "--dport", "1900",
-                  "-o", default_device, "--jump", "RETURN")
-        # allow multicast Bonjour/mDNS
-        ip4tables("--append", BITMASK_CHAIN,
-                  "--protocol", "udp",
-                  "--destination", "224.0.0.251", "--dport", "5353",
-                  "-o", default_device, "--jump", "RETURN")
-    if local_network_ipv6:
-        ip6tables("--append", BITMASK_CHAIN,
-                  "--destination", local_network_ipv6, "-o", default_device,
-                  "--jump", "ACCEPT")
-        # allow multicast Simple Service Discovery Protocol
-        ip6tables("--append", BITMASK_CHAIN,
-                  "--protocol", "udp",
-                  "--destination", "FF05::C", "--dport", "1900",
-                  "-o", default_device, "--jump", "RETURN")
-        # allow multicast Bonjour/mDNS
-        ip6tables("--append", BITMASK_CHAIN,
-                  "--protocol", "udp",
-                  "--destination", "FF02::FB", "--dport", "5353",
-                  "-o", default_device, "--jump", "RETURN")
-
-    # allow ipv4 traffic to gateways
-    for gateway in gateways:
-        ip4tables("--append", BITMASK_CHAIN, "--destination", gateway,
-                  "-o", default_device, "--jump", "ACCEPT")
-
-    # log rejected packets to syslog
-    if DEBUG:
-        iptables("--append", BITMASK_CHAIN, "-o", default_device,
-                 "--jump", "LOG", "--log-prefix", "iptables denied: ",
-                 "--log-level", "7")
-
-    # for now, ensure all other ipv6 packets get rejected (regardless of
-    # device). not sure why, but "-p any" doesn't work.
-    ip6tables("--append", BITMASK_CHAIN, "-p", "tcp", "--jump", "REJECT")
-    ip6tables("--append", BITMASK_CHAIN, "-p", "udp", "--jump", "REJECT")
-
-    # reject all other ipv4 sent over the default device
-    ip4tables("--append", BITMASK_CHAIN, "-o",
-              default_device, "--jump", "REJECT")
-
-
-def firewall_stop():
-    """
-    Stop the firewall. Because we really really always want the firewall to
-    be stopped if at all possible, this function is cautious and contains a
-    lot of trys and excepts.
-
-    If there were any problems, we raise an exception at the end. This allows
-    the calling code to retry stopping the firewall. Stopping the firewall
-    can fail if iptables is being run by another process (only one iptables
-    command can be run at a time).
-    """
-    ok = True
-
-    # -t filter -D OUTPUT -j bitmask
-    try:
-        iptables("--delete", "OUTPUT", "--jump", BITMASK_CHAIN, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to remove bitmask firewall from OUTPUT chain "
-              "(maybe it is already removed?)", exc)
-        ok = False
-
-    # -t nat -D OUTPUT -j bitmask
-    try:
-        ip4tables("-t", "nat", "--delete", "OUTPUT",
-                  "--jump", BITMASK_CHAIN_NAT_OUT, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to remove bitmask firewall from OUTPUT chain "
-              "in 'nat' table (maybe it is already removed?)", exc)
-        ok = False
-
-    # -t nat -D POSTROUTING -j bitmask_postrouting
-    try:
-        ip4tables("-t", "nat", "--delete", "POSTROUTING",
-                  "--jump", BITMASK_CHAIN_NAT_POST, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to remove bitmask firewall from POSTROUTING "
-              "chain in 'nat' table (maybe it is already removed?)", exc)
-        ok = False
-
-    # -t filter --delete-chain bitmask
-    try:
-        ip4tables("--flush", BITMASK_CHAIN, throw=True)
-        ip4tables("--delete-chain", BITMASK_CHAIN, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to flush and delete bitmask ipv4 firewall "
-              "chain (maybe it is already destroyed?)", exc)
-        ok = False
-
-    # -t nat --delete-chain bitmask
-    try:
-        ip4tables("-t", "nat", "--flush", BITMASK_CHAIN_NAT_OUT, throw=True)
-        ip4tables("-t", "nat", "--delete-chain",
-                  BITMASK_CHAIN_NAT_OUT, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to flush and delete bitmask ipv4 firewall "
-              "chain in 'nat' table (maybe it is already destroyed?)", exc)
-        ok = False
-
-    # -t nat --delete-chain bitmask_postrouting
-    try:
-        ip4tables("-t", "nat", "--flush", BITMASK_CHAIN_NAT_POST, throw=True)
-        ip4tables("-t", "nat", "--delete-chain",
-                  BITMASK_CHAIN_NAT_POST, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to flush and delete bitmask ipv4 firewall "
-              "chain in 'nat' table (maybe it is already destroyed?)", exc)
-        ok = False
-
-    # -t filter --delete-chain bitmask (ipv6)
-    try:
-        ip6tables("--flush", BITMASK_CHAIN, throw=True)
-        ip6tables("--delete-chain", BITMASK_CHAIN, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to flush and delete bitmask ipv6 firewall "
-              "chain (maybe it is already destroyed?)", exc)
-        ok = False
-
-    if not (ok or ipv4_chain_exists or ipv6_chain_exists):
-        raise Exception("firewall might still be left up. "
-                        "Please try `firewall stop` again.")
-
-
-def fw_email_start(args):
-    """
-    Bring up the email firewall.
-
-    :param args: the user uid of the bitmask process
-    :type args: list
-    """
-    # add custom chain "bitmask_email" to front of INPUT chain
-    if not ipv4_chain_exists(BITMASK_CHAIN_EMAIL):
-        ip4tables("--new-chain", BITMASK_CHAIN_EMAIL)
-    if not ipv6_chain_exists(BITMASK_CHAIN_EMAIL):
-        ip6tables("--new-chain", BITMASK_CHAIN_EMAIL)
-    iptables("--insert", "INPUT", "--jump", BITMASK_CHAIN_EMAIL)
-
-    # add custom chain "bitmask_email_output" to front of OUTPUT chain
-    if not ipv4_chain_exists(BITMASK_CHAIN_EMAIL_OUT):
-        ip4tables("--new-chain", BITMASK_CHAIN_EMAIL_OUT)
-    if not ipv6_chain_exists(BITMASK_CHAIN_EMAIL_OUT):
-        ip6tables("--new-chain", BITMASK_CHAIN_EMAIL_OUT)
-    iptables("--insert", "OUTPUT", "--jump", BITMASK_CHAIN_EMAIL_OUT)
-
-    # Disable the access to imap and smtp from outside
-    iptables("--append", BITMASK_CHAIN_EMAIL,
-             "--in-interface", LOCAL_INTERFACE, "--protocol", "tcp",
-             "--dport", IMAP_PORT, "--jump", "ACCEPT")
-    iptables("--append", BITMASK_CHAIN_EMAIL,
-             "--in-interface", LOCAL_INTERFACE, "--protocol", "tcp",
-             "--dport", SMTP_PORT, "--jump", "ACCEPT")
-    iptables("--append", BITMASK_CHAIN_EMAIL,
-             "--protocol", "tcp", "--dport", IMAP_PORT, "--jump", "REJECT")
-    iptables("--append", BITMASK_CHAIN_EMAIL,
-             "--protocol", "tcp", "--dport", SMTP_PORT, "--jump", "REJECT")
-
-    if not args or not PARAM_FORMATS["UID"](args[0]):
-        raise Exception("No uid given")
-    uid = args[0]
-
-    # Only the unix 'uid' have access to the email imap and smtp ports
-    iptables("--append", BITMASK_CHAIN_EMAIL_OUT,
-             "--out-interface", LOCAL_INTERFACE,
-             "--match", "owner", "--uid-owner", uid, "--protocol", "tcp",
-             "--dport", IMAP_PORT, "--jump", "ACCEPT")
-    iptables("--append", BITMASK_CHAIN_EMAIL_OUT,
-             "--out-interface", LOCAL_INTERFACE,
-             "--match", "owner", "--uid-owner", uid, "--protocol", "tcp",
-             "--dport", SMTP_PORT, "--jump", "ACCEPT")
-    iptables("--append", BITMASK_CHAIN_EMAIL_OUT,
-             "--out-interface", LOCAL_INTERFACE,
-             "--protocol", "tcp", "--dport", IMAP_PORT, "--jump", "REJECT")
-    iptables("--append", BITMASK_CHAIN_EMAIL_OUT,
-             "--out-interface", LOCAL_INTERFACE,
-             "--protocol", "tcp", "--dport", SMTP_PORT, "--jump", "REJECT")
-
-
-def fw_email_stop():
-    """
-    Stop the email firewall.
-    """
-    ok = True
-
-    try:
-        iptables("--delete", "INPUT", "--jump", BITMASK_CHAIN_EMAIL,
-                 throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to remove bitmask email firewall from INPUT "
-              "chain (maybe it is already removed?)", exc)
-        ok = False
-
-    try:
-        iptables("--delete", "OUTPUT", "--jump", BITMASK_CHAIN_EMAIL_OUT,
-                 throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to remove bitmask email firewall from OUTPUT "
-              "chain (maybe it is already removed?)", exc)
-        ok = False
-
-    try:
-        ip4tables("--flush", BITMASK_CHAIN_EMAIL, throw=True)
-        ip4tables("--delete-chain", BITMASK_CHAIN_EMAIL, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to flush and delete bitmask ipv4 email firewall "
-              "chain (maybe it is already destroyed?)", exc)
-        ok = False
-
-    try:
-        ip6tables("--flush", BITMASK_CHAIN_EMAIL, throw=True)
-        ip6tables("--delete-chain", BITMASK_CHAIN_EMAIL, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to flush and delete bitmask ipv6 email firewall "
-              "chain (maybe it is already destroyed?)", exc)
-        ok = False
-
-    try:
-        ip4tables("--flush", BITMASK_CHAIN_EMAIL_OUT, throw=True)
-        ip4tables("--delete-chain", BITMASK_CHAIN_EMAIL_OUT, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to flush and delete bitmask ipv4 email firewall "
-              "chain (maybe it is already destroyed?)", exc)
-        ok = False
-
-    try:
-        ip6tables("--flush", BITMASK_CHAIN_EMAIL_OUT, throw=True)
-        ip6tables("--delete-chain", BITMASK_CHAIN_EMAIL_OUT, throw=True)
-    except subprocess.CalledProcessError as exc:
-        debug("INFO: not able to flush and delete bitmask ipv6 email firewall "
-              "chain (maybe it is already destroyed?)", exc)
-        ok = False
-
-    if not (ok or ipv4_chain_exists or ipv6_chain_exists):
-        raise Exception("email firewall might still be left up. "
-                        "Please try `fw-email stop` again.")
-
-
-#
-# MAIN
-#
-
-
-def main():
-    """
-    Entry point for cmdline execution.
-    """
-    # TODO use argparse instead.
-
-    if len(sys.argv) >= 2:
-        command = "_".join(sys.argv[1:3])
-        args = sys.argv[3:]
-
-        is_restart = False
-        if args and args[0] == "restart":
-            is_restart = True
-            args.remove('restart')
-
-        if command == "version":
-            print(VERSION)
-            exit(0)
-
-        if os.getuid() != 0:
-            bail("ERROR: must be run as root")
-
-        if command == "openvpn_start":
-            openvpn_start(args)
-
-        elif command == "openvpn_stop":
-            openvpn_stop(args)
-
-        elif command == "firewall_start":
-            try:
-                firewall_start(args)
-            except Exception as ex:
-                if not is_restart:
-                    firewall_stop()
-                bail("ERROR: could not start firewall", ex)
-
-        elif command == "firewall_stop":
-            try:
-                firewall_stop()
-            except Exception as ex:
-                bail("ERROR: could not stop firewall", ex)
-
-        elif command == "firewall_isup":
-            if ipv4_chain_exists(BITMASK_CHAIN):
-                log("%s: INFO: bitmask firewall is up" % (SCRIPT,))
-            else:
-                bail("INFO: bitmask firewall is down")
-
-        elif command == "fw-email_start":
-            try:
-                fw_email_start(args)
-            except Exception as ex:
-                if not is_restart:
-                    fw_email_stop()
-                bail("ERROR: could not start email firewall", ex)
-
-        elif command == "fw-email_stop":
-            try:
-                fw_email_stop()
-            except Exception as ex:
-                bail("ERROR: could not stop email firewall", ex)
-
-        elif command == "fw-email_isup":
-            if ipv4_chain_exists(BITMASK_CHAIN_EMAIL):
-                log("%s: INFO: bitmask email firewall is up" % (SCRIPT,))
-            else:
-                bail("INFO: bitmask email firewall is down")
-
-        else:
-            bail("ERROR: No such command")
-    else:
-        bail("ERROR: No such command")
-
-if __name__ == "__main__":
-    debug(" ".join(sys.argv))
-    main()
-    log("done")
-    exit(0)