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-rwxr-xr-xpkg/linux/bitmask-root332
-rwxr-xr-xpkg/linux/resolv-update90
-rwxr-xr-xpkg/linux/update-resolv-conf58
3 files changed, 55 insertions, 425 deletions
diff --git a/pkg/linux/bitmask-root b/pkg/linux/bitmask-root
index 3ffd0eee..4463dbaa 100755
--- a/pkg/linux/bitmask-root
+++ b/pkg/linux/bitmask-root
@@ -60,24 +60,12 @@ IP = "/bin/ip"
IPTABLES = "/sbin/iptables"
IP6TABLES = "/sbin/ip6tables"
-RESOLVCONF_SYSTEM_BIN = "/sbin/resolvconf"
-RESOLVCONF_LEAP_BIN = "/usr/local/sbin/leap-resolvconf"
-
OPENVPN_USER = "nobody"
OPENVPN_GROUP = "nogroup"
LEAPOPENVPN = "LEAPOPENVPN"
OPENVPN_SYSTEM_BIN = "/usr/sbin/openvpn" # Debian location
OPENVPN_LEAP_BIN = "/usr/local/sbin/leap-openvpn" # installed by bundle
-
-"""
-The path to the script to update resolv.conf
-"""
-# XXX We have to check if we have a valid resolvconf, and use
-# the old resolv-update if not.
-LEAP_UPDATE_RESOLVCONF_FILE = "/etc/leap/update-resolv-conf"
-LEAP_RESOLV_UPDATE = "/etc/leap/resolv-update"
-
FIXED_FLAGS = [
"--setenv", "LEAPOPENVPN", "1",
"--nobind",
@@ -137,7 +125,6 @@ syslog.openlog(SCRIPT)
## UTILITY
##
-
def is_valid_address(value):
"""
Validate that the passed ip is a valid IP address.
@@ -154,33 +141,6 @@ def is_valid_address(value):
return False
-def has_system_resolvconf():
- """
- Return True if resolvconf is found in the system.
-
- :rtype: bool
- """
- return os.path.isfile(RESOLVCONF)
-
-
-def has_valid_update_resolvconf():
- """
- Return True if a valid update-resolv-conf script is found in the system.
-
- :rtype: bool
- """
- return os.path.isfile(LEAP_UPDATE_RESOLVCONF_FILE)
-
-
-def has_valid_leap_resolv_update():
- """
- Return True if a valid resolv-update script is found in the system.
-
- :rtype: bool
- """
- return os.path.isfile(LEAP_RESOLV_UPDATE)
-
-
def split_list(_list, regex):
"""
Split a list based on a regex:
@@ -235,135 +195,6 @@ def get_process_list():
return filter(None, res)
-class Daemon(object):
- """
- A generic daemon class.
- """
- def __init__(self, pidfile, stdin='/dev/null',
- stdout='/dev/null', stderr='/dev/null'):
- self.stdin = stdin
- self.stdout = stdout
- self.stderr = stderr
- self.pidfile = pidfile
-
- def daemonize(self):
- """
- Do the UNIX double-fork magic, see Stevens' "Advanced
- Programming in the UNIX Environment" for details (ISBN 0201563177)
- http://www.erlenstar.demon.co.uk/unix/faq_2.html#SEC16
- """
- try:
- pid = os.fork()
- if pid > 0:
- # exit first parent
- sys.exit(0)
- except OSError, e:
- sys.stderr.write(
- "fork #1 failed: %d (%s)\n" % (e.errno, e.strerror))
- sys.exit(1)
-
- # decouple from parent environment
- os.chdir("/")
- os.setsid()
- os.umask(0)
-
- # do second fork
- try:
- pid = os.fork()
- if pid > 0:
- # exit from second parent
- sys.exit(0)
- except OSError, e:
- sys.stderr.write(
- "fork #2 failed: %d (%s)\n" % (e.errno, e.strerror))
- sys.exit(1)
-
- # redirect standard file descriptors
- sys.stdout.flush()
- sys.stderr.flush()
- si = file(self.stdin, 'r')
- so = file(self.stdout, 'a+')
- se = file(self.stderr, 'a+', 0)
- os.dup2(si.fileno(), sys.stdin.fileno())
- os.dup2(so.fileno(), sys.stdout.fileno())
- os.dup2(se.fileno(), sys.stderr.fileno())
-
- # write pidfile
- atexit.register(self.delpid)
- pid = str(os.getpid())
- file(self.pidfile, 'w+').write("%s\n" % pid)
-
- def delpid(self):
- """
- Delete the pidfile.
- """
- os.remove(self.pidfile)
-
- def start(self, *args):
- """
- Start the daemon.
- """
- # Check for a pidfile to see if the daemon already runs
- try:
- pf = file(self.pidfile, 'r')
- pid = int(pf.read().strip())
- pf.close()
- except IOError:
- pid = None
-
- if pid:
- message = "pidfile %s already exist. Daemon already running?\n"
- sys.stderr.write(message % self.pidfile)
- sys.exit(1)
-
- # Start the daemon
- self.daemonize()
- self.run(args)
-
- def stop(self):
- """
- Stop the daemon.
- """
- # Get the pid from the pidfile
- try:
- pf = file(self.pidfile, 'r')
- pid = int(pf.read().strip())
- pf.close()
- except IOError:
- pid = None
-
- if not pid:
- message = "pidfile %s does not exist. Daemon not running?\n"
- sys.stderr.write(message % self.pidfile)
- return # not an error in a restart
-
- # Try killing the daemon process
- try:
- while 1:
- os.kill(pid, signal.SIGTERM)
- time.sleep(0.1)
- except OSError, err:
- err = str(err)
- if err.find("No such process") > 0:
- if os.path.exists(self.pidfile):
- os.remove(self.pidfile)
- else:
- log(str(err))
- sys.exit(1)
-
- def restart(self):
- """
- Restart the daemon.
- """
- self.stop()
- self.start()
-
- def run(self):
- """
- This should be overridden by derived classes.
- """
-
-
def run(command, *args, **options):
"""
Run an external command.
@@ -400,11 +231,11 @@ def run(command, *args, **options):
subprocess.check_call(parts, stdout=devnull, stderr=devnull)
return 0
except subprocess.CalledProcessError as exc:
- if DEBUG:
- logger.exception(exc)
if _exitcode:
- debug("ERROR: Could not run %s: %s" % (exc.cmd, exc.output),
- exception=exc)
+ 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
@@ -452,7 +283,6 @@ def bail(msg=None, exception=None):
## OPENVPN
##
-
def get_openvpn_bin():
"""
Return the path for either the system openvpn or the one the
@@ -543,85 +373,9 @@ def openvpn_stop(args):
os.kill(int(pid), signal.SIGTERM)
##
-## DNS
-##
-
-
-def get_resolvconf_bin():
- """
- Return the path for either the system resolvconf or the one the
- bundle has put there.
- """
- if os.path.isfile(RESOLVCONF_SYSTEM_BIN):
- return RESOLVCONF_SYSTEM_BIN
-
- # the bundle option should be removed from the debian package.
- if os.path.isfile(RESOLVCONF_LEAP_BIN):
- return RESOLVCONF_LEAP_BIN
-
-RESOLVCONF = get_resolvconf_bin()
-
-
-class NameserverSetter(Daemon):
- """
- A daemon that will add leap nameserver inside the tunnel
- to the system `resolv.conf`
- """
-
- def run(self, *args):
- """
- Run when daemonized.
- """
- if args:
- ip_address = args[0]
- self.set_dns_nameserver(ip_address)
-
- def set_dns_nameserver(self, ip_address):
- """
- Add the tunnel DNS server to `resolv.conf`
-
- :param ip_address: the ip to add to `resolv.conf`
- :type ip_address: str
- """
- if os.path.isfile(RESOLVCONF):
- process = run(RESOLVCONF, "-a", "bitmask", input=True)
- process.communicate("nameserver %s\n" % ip_address)
- else:
- bail("ERROR: package openresolv or resolvconf not installed.")
-
-nameserver_setter = NameserverSetter('/tmp/leap-dns-up.pid')
-
-
-class NameserverRestorer(Daemon):
- """
- A daemon that will restore the previous nameservers.
- """
-
- def run(self, *args):
- """
- Run when daemonized.
- """
- self.restore_dns_nameserver()
-
- def restore_dns_nameserver(self):
- """
- Remove tunnel DNS server from `resolv.conf`
- """
- if os.path.isfile(RESOLVCONF):
- run(RESOLVCONF, "-d", "bitmask")
- else:
- log("%s: ERROR: package openresolv "
- "or resolvconf not installed." %
- (SCRIPT,))
-
-nameserver_restorer = NameserverRestorer('/tmp/leap-dns-down.pid')
-
-
-##
## FIREWALL
##
-
def get_gateways(gateways):
"""
Filter a passed sequence of gateways, returning only the valid ones.
@@ -738,15 +492,19 @@ def ip6tables(*args, **options):
# the chain.
#
-def ipv4_chain_exists(chain):
+def ipv4_chain_exists(chain, table=None):
"""
- Check if a given chain exists.
+ 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
"""
- code = run(IPTABLES, "--list", chain, "--numeric", exitcode=True)
+ if table:
+ 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:
@@ -758,7 +516,7 @@ def ipv4_chain_exists(chain):
def ipv6_chain_exists(chain):
"""
- Check if a given chain exists.
+ see ipv4_chain_exists()
:param chain: the chain to check against
:type chain: str
@@ -773,6 +531,13 @@ def ipv6_chain_exists(chain):
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.
+ """
+ file = open('/proc/sys/net/ipv4/ip_forward', 'w')
+ file.write('1\n')
+ file.close
def firewall_start(args):
"""
@@ -786,23 +551,29 @@ def firewall_start(args):
local_network_ipv6 = get_local_network_ipv6(default_device)
gateways = get_gateways(args)
- # add custom chain "bitmask" to front of OUTPUT chain
+ # 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'):
+ ip4tables("--table", "nat", "--new-chain", BITMASK_CHAIN)
if not ipv6_chain_exists(BITMASK_CHAIN):
ip6tables("--new-chain", BITMASK_CHAIN)
+ ip4tables("--table", "nat", "--insert", "OUTPUT", "--jump", BITMASK_CHAIN)
iptables("--insert", "OUTPUT", "--jump", BITMASK_CHAIN)
- # allow DNS over VPN
- for allowed_dns in [NAMESERVER, "127.0.0.1", "127.0.1.1"]:
- ip4tables("--append", BITMASK_CHAIN, "--protocol", "udp",
- "--dport", "53", "--destination", allowed_dns,
- "--jump", "ACCEPT")
-
- # block DNS requests to anyone but the service provider or localhost
- # (when we actually route ipv6, we will need DNS rules for it too)
- ip4tables("--append", BITMASK_CHAIN, "--protocol", "udp", "--dport", "53",
- "--jump", "REJECT")
+ # 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, "--protocol", "udp",
+ "--dport", "53", "--jump", "DNAT", "--to", NAMESERVER+":53")
+ ip4tables("-t", "nat", "--append", BITMASK_CHAIN, "--protocol", "tcp",
+ "--dport", "53", "--jump", "DNAT", "--to", NAMESERVER+":53")
# allow traffic to IPs on local network
if local_network_ipv4:
@@ -846,8 +617,7 @@ def firewall_start(args):
"--log-level", "7")
# for now, ensure all other ipv6 packets get rejected (regardless of
- # device)
- # (not sure why, but "-p any" doesn't work)
+ # 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")
@@ -868,30 +638,41 @@ def firewall_stop():
"""
ok = True
try:
- iptables("--wait", "--delete", "OUTPUT", "--jump", BITMASK_CHAIN, throw=True)
+ 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
+ try:
+ ip4tables("-t", "nat", "--delete", "OUTPUT", "--jump", BITMASK_CHAIN, throw=True)
except subprocess.CalledProcessError as exc:
- log("INFO: not able to remove bitmask firewall from OUTPUT chain (maybe it is already removed?)", exc)
+ debug("INFO: not able to remove bitmask firewall from OUTPUT chain in 'nat' table (maybe it is already removed?)", exc)
ok = False
try:
ip4tables("--flush", BITMASK_CHAIN, throw=True)
ip4tables("--delete-chain", BITMASK_CHAIN, throw=True)
except subprocess.CalledProcessError as exc:
- log("INFO: not able to flush and delete bitmask ipv4 firewall chain (maybe it is already destroyed?)", exc)
+ debug("INFO: not able to flush and delete bitmask ipv4 firewall chain (maybe it is already destroyed?)", exc)
+ ok = False
+ try:
+ ip4tables("-t", "nat", "--flush", BITMASK_CHAIN, throw=True)
+ ip4tables("-t", "nat", "--delete-chain", BITMASK_CHAIN, 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
try:
ip6tables("--flush", BITMASK_CHAIN, throw=True)
ip6tables("--delete-chain", BITMASK_CHAIN, throw=True)
except subprocess.CalledProcessError as exc:
- log("INFO: not able to flush and delete bitmask ipv6 firewall chain (maybe it is already destroyed?)", exc)
+ debug("INFO: not able to flush and delete bitmask ipv6 firewall chain (maybe it is already destroyed?)", exc)
ok = False
- if not ok:
+ if not (ok or ipv4_chain_exists or ipv6_chain_exists):
raise Exception("firewall might still be left up. Please try `firewall stop` again.")
+
##
## MAIN
##
-
def main():
"""
Entry point for cmdline execution.
@@ -923,17 +704,14 @@ def main():
elif command == "firewall_start":
try:
firewall_start(args)
- nameserver_setter.start(NAMESERVER)
except Exception as ex:
if not is_restart:
- nameserver_restorer.start()
firewall_stop()
bail("ERROR: could not start firewall", ex)
elif command == "firewall_stop":
try:
firewall_stop()
- nameserver_restorer.start()
except Exception as ex:
bail("ERROR: could not stop firewall", ex)
@@ -951,5 +729,5 @@ def main():
if __name__ == "__main__":
debug(" ".join(sys.argv))
main()
- log("%s: done" % (SCRIPT,))
+ log("done")
exit(0)
diff --git a/pkg/linux/resolv-update b/pkg/linux/resolv-update
deleted file mode 100755
index c308b788..00000000
--- a/pkg/linux/resolv-update
+++ /dev/null
@@ -1,90 +0,0 @@
-#!/bin/bash
-#
-# Parses options from openvpn to update resolv.conf
-#
-# The only way to enforce that a linux system will not leak DNS
-# queries is to replace /etc/resolv.conf with a file that only
-# has the DNS resolver specified by the VPN.
-#
-# That is what this script does. This is what resolvconf is for,
-# but sadly it does not always work.
-#
-# Example envs set from openvpn:
-# foreign_option_1='dhcp-option DNS 193.43.27.132'
-# foreign_option_2='dhcp-option DNS 193.43.27.133'
-# foreign_option_3='dhcp-option DOMAIN be.bnc.ch'
-#
-
-function up() {
-
- comment=$(
-cat <<SETVAR
-#
-# This is a temporary resolv.conf set by the Bitmask in order to
-# strictly enforce that DNS lookups are secured by the VPN.
-#
-# When Bitmask quits or the VPN connection it manages is dropped,
-# this file will be replace with the regularly scheduled /etc/resolv.conf
-#
-# If you want custom entries to appear in this file while Bitmask is running,
-# put them in /etc/leap/resolv-head or /etc/leap/resolv-tail. These files
-# should only be writable by root.
-#
-
-SETVAR
-)
-
- if [ -f /etc/leap/resolv-head ] ; then
- custom_head=$(cat /etc/leap/resolv-head)
- else
- custom_head=""
- fi
-
- if [ -f /etc/leap/resolv-tail ] ; then
- custom_tail=$(cat /etc/leap/resolv-tail)
- else
- custom_tail=""
- fi
-
- for optionname in ${!foreign_option_*} ; do
- option="${!optionname}"
- echo $option
- part1=$(echo "$option" | cut -d " " -f 1)
- if [ "$part1" == "dhcp-option" ] ; then
- part2=$(echo "$option" | cut -d " " -f 2)
- part3=$(echo "$option" | cut -d " " -f 3)
- if [ "$part2" == "DNS" ] ; then
- IF_DNS_NAMESERVERS="$IF_DNS_NAMESERVERS $part3"
- fi
- if [ "$part2" == "DOMAIN" ] ; then
- IF_DNS_SEARCH="$IF_DNS_SEARCH $part3"
- fi
- fi
- done
- R=""
- for SS in $IF_DNS_SEARCH ; do
- R="${R}search $SS
-"
- done
- for NS in $IF_DNS_NAMESERVERS ; do
- R="${R}nameserver $NS
-"
- done
- cp /etc/resolv.conf /etc/resolv.conf.bak
- echo "$comment
-$custom_head
-$R
-$custom_tail" > /etc/resolv.conf
-}
-
-function down() {
- if [ -f /etc/resolv.conf.bak ] ; then
- cat /etc/resolv.conf.bak > /etc/resolv.conf
- rm /etc/resolv.conf.bak
- fi
-}
-
-case $script_type in
- up) up ;;
- down) down ;;
-esac
diff --git a/pkg/linux/update-resolv-conf b/pkg/linux/update-resolv-conf
deleted file mode 100755
index 76c69413..00000000
--- a/pkg/linux/update-resolv-conf
+++ /dev/null
@@ -1,58 +0,0 @@
-#!/bin/bash
-#
-# Parses DHCP options from openvpn to update resolv.conf
-# To use set as 'up' and 'down' script in your openvpn *.conf:
-# up /etc/leap/update-resolv-conf
-# down /etc/leap/update-resolv-conf
-#
-# Used snippets of resolvconf script by Thomas Hood and Chris Hanson.
-# Licensed under the GNU GPL. See /usr/share/common-licenses/GPL.
-#
-# Example envs set from openvpn:
-#
-# foreign_option_1='dhcp-option DNS 193.43.27.132'
-# foreign_option_2='dhcp-option DNS 193.43.27.133'
-# foreign_option_3='dhcp-option DOMAIN be.bnc.ch'
-#
-
-[ -x /sbin/resolvconf ] || exit 0
-[ "$script_type" ] || exit 0
-[ "$dev" ] || exit 0
-
-split_into_parts()
-{
- part1="$1"
- part2="$2"
- part3="$3"
-}
-
-case "$script_type" in
- up)
- NMSRVRS=""
- SRCHS=""
- for optionvarname in ${!foreign_option_*} ; do
- option="${!optionvarname}"
- echo "$option"
- split_into_parts $option
- if [ "$part1" = "dhcp-option" ] ; then
- if [ "$part2" = "DNS" ] ; then
- NMSRVRS="${NMSRVRS:+$NMSRVRS }$part3"
- elif [ "$part2" = "DOMAIN" ] ; then
- SRCHS="${SRCHS:+$SRCHS }$part3"
- fi
- fi
- done
- R=""
- [ "$SRCHS" ] && R="search $SRCHS
-"
- for NS in $NMSRVRS ; do
- R="${R}nameserver $NS
-"
- done
- echo -n "$R" | /sbin/resolvconf -a "${dev}.openvpn"
- ;;
- down)
- /sbin/resolvconf -d "${dev}.openvpn"
- ;;
-esac
-
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-11 02:16:33 +0000