1 files changed, 73 insertions, 0 deletions
diff --git a/src/leap/bitmask/vpn/_observer.py b/src/leap/bitmask/vpn/_observer.py
new file mode 100644
index 0000000..1bb363d
--- /dev/null
+++ b/src/leap/bitmask/vpn/_observer.py
@@ -0,0 +1,73 @@
+from twisted.logger import Logger
+
+logger = Logger()
+
+
+class VPNObserver(object):
+    """
+    A class containing different patterns in the openvpn output that
+    we can react upon.
+    """
+
+    _events = {
+        'NETWORK_UNREACHABLE': (
+            'Network is unreachable (code=101)',),
+        'PROCESS_RESTART_TLS': (
+            "SIGTERM[soft,tls-error]",),
+        'PROCESS_RESTART_PING': (
+            "SIGTERM[soft,ping-restart]",),
+        'INITIALIZATION_COMPLETED': (
+            "Initialization Sequence Completed",),
+    }
+
+    def __init__(self, signaler=None):
+        self._signaler = signaler
+
+    def watch(self, line):
+        """
+        Inspects line searching for the different patterns. If a match
+        is found, try to emit the corresponding signal.
+
+        :param line: a line of openvpn output
+        :type line: str
+        """
+        chained_iter = chain(*[
+            zip(repeat(key, len(l)), l)
+            for key, l in self._events.iteritems()])
+        for event, pattern in chained_iter:
+            if pattern in line:
+                logger.debug('pattern matched! %s' % pattern)
+                break
+        else:
+            return
+
+        sig = self._get_signal(event)
+        if sig is not None:
+            if self._signaler is not None:
+                self._signaler.signal(sig)
+            return
+        else:
+            logger.debug('We got %s event from openvpn output but we could '
+                         'not find a matching signal for it.' % event)
+
+    def _get_signal(self, event):
+        """
+        Tries to get the matching signal from the eip signals
+        objects based on the name of the passed event (in lowercase)
+
+        :param event: the name of the event that we want to get a signal for
+        :type event: str
+        :returns: a Signaler signal or None
+        :rtype: str or None
+        """
+        if self._signaler is None:
+            return
+        sig = self._signaler
+        signals = {
+            "network_unreachable": sig.eip_network_unreachable,
+            "process_restart_tls": sig.eip_process_restart_tls,
+            "process_restart_ping": sig.eip_process_restart_ping,
+            "initialization_completed": sig.eip_connected
+        }
+        return signals.get(event.lower())
+