add null checks, fix error on get_default_device. Closes: #5732

Also:

-make firewall aware of restarts, and not tear down the fw if an error
 happens while a restart is going on.

-notify errors to syslog.

1 files changed, 18 insertions, 8 deletions

diff --git a/pkg/linux/bitmask-root b/pkg/linux/bitmask-root
index 82e8799f..d1bf656e 100755
--- a/pkg/linux/bitmask-root
+++ b/pkg/linux/bitmask-root
@@ -22,14 +22,15 @@ It should only be called by the Bitmask application.
 
 USAGE:
   bitmask-root firewall stop
-  bitmask-root firewall start GATEWAY1 GATEWAY2 ...
+  bitmask-root firewall start [restart] GATEWAY1 GATEWAY2 ...
   bitmask-root openvpn stop
   bitmask-root openvpn start CONFIG1 CONFIG1 ...
 
 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.
+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
@@ -38,12 +39,12 @@ import os
 import re
 import signal
 import socket
+import syslog
 import subprocess
 import sys
 import time
 import traceback
 
-
 cmdcheck = subprocess.check_output
 
 ##
@@ -129,6 +130,8 @@ if DEBUG:
     logger.setLevel(logging.DEBUG)
     logger.addHandler(ch)
 
+syslog.openlog(SCRIPT)
+
 ##
 ## UTILITY
 ##
@@ -413,6 +416,7 @@ def bail(msg=None, exception=None):
     """
     if msg is not None:
         print("%s: %s" % (SCRIPT, msg))
+        syslog.syslog(syslog.LOG_ERR, msg)
     if exception is not None:
         traceback.print_exc()
     exit(1)
@@ -614,7 +618,7 @@ def get_default_device():
     """
     routes = subprocess.check_output([IP, "route", "show"])
     match = re.search("^default .*dev ([^\s]*) .*$", routes, flags=re.M)
-    if match.groups():
+    if match and match.groups():
         return match.group(1)
     else:
         bail("Could not find default device")
@@ -629,7 +633,7 @@ def get_local_network_ipv4(device):
     """
     addresses = cmdcheck([IP, "-o", "address", "show", "dev", device])
     match = re.search("^.*inet ([^ ]*) .*$", addresses, flags=re.M)
-    if match.groups():
+    if match and match.groups():
         return match.group(1)
     else:
         return None
@@ -644,7 +648,7 @@ def get_local_network_ipv6(device):
     """
     addresses = cmdcheck([IP, "-o", "address", "show", "dev", device])
     match = re.search("^.*inet6 ([^ ]*) .*$", addresses, flags=re.M)
-    if match.groups():
+    if match and match.groups():
         return match.group(1)
     else:
         return None
@@ -819,6 +823,11 @@ def main():
         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 == "openvpn_start":
             openvpn_start(args)
 
@@ -830,8 +839,9 @@ def main():
                 firewall_start(args)
                 nameserver_setter.start(NAMESERVER)
             except Exception as ex:
-                nameserver_restorer.start()
-                firewall_stop()
+                if not is_restart:
+		    nameserver_restorer.start()
+		    firewall_stop()
                 bail("ERROR: could not start firewall", ex)
 
         elif command == "firewall_stop":