Merge branch 'feature/network_check' into develop

Conflicts:
	src/leap/baseapp/mainwindow.py
	src/leap/eip/tests/test_checks.py

5 files changed, 404 insertions, 0 deletions

diff --git a/src/leap/base/checks.py b/src/leap/base/checks.py
new file mode 100644
index 00000000..84f9dd46
--- /dev/null
+++ b/src/leap/base/checks.py
@@ -0,0 +1,139 @@
+# -*- coding: utf-8 -*-
+import logging
+import platform
+
+import netifaces
+import ping
+import requests
+
+from leap.base import constants
+from leap.base import exceptions
+
+logger = logging.getLogger(name=__name__)
+
+
+class LeapNetworkChecker(object):
+    """
+    all network related checks
+    """
+    # #718
+    # XXX get provider gateway as a parameter
+    # for constructor.
+    # def __init__(self, *args, **kwargs):
+    # ...
+    #   provider_gw = kwargs.pop('provider_gw', None)
+    #   self.provider_gateway = provider_gw
+
+    def run_all(self, checker=None):
+        if not checker:
+            checker = self
+        self.error = None  # ?
+
+        # for MVS
+        checker.check_tunnel_default_interface()
+        checker.check_internet_connection()
+        checker.is_internet_up()
+
+        # XXX We are pinging the default gateway for our connection right?
+        # kali: 2012-10-05 20:59 -- I think we should get
+        # also the default gateway and ping it instead.
+        checker.ping_gateway()
+
+        # something like: ?
+        # see __init__ above
+        # if self.provider_gateway:
+        #     checker.ping_gateway(self.provider_gateway)
+
+    def check_internet_connection(self):
+        try:
+            # XXX remove this hardcoded random ip
+            # ping leap.se or eip provider instead...?
+            requests.get('http://216.172.161.165')
+
+        except (requests.HTTPError, requests.RequestException) as e:
+            raise exceptions.NoInternetConnection(e.message)
+        except requests.ConnectionError as e:
+            error = "Unidentified Connection Error"
+            if e.message == "[Errno 113] No route to host":
+                if not self.is_internet_up():
+                    error = "No valid internet connection found."
+                else:
+                    error = "Provider server appears to be down."
+            logger.error(error)
+            raise exceptions.NoInternetConnection(error)
+        logger.debug('Network appears to be up.')
+
+    def is_internet_up(self):
+        iface, gateway = self.get_default_interface_gateway()
+        self.ping_gateway(self)
+
+    def check_tunnel_default_interface(self):
+        """
+        Raises an TunnelNotDefaultRouteError
+        (including when no routes are present)
+        """
+        if not platform.system() == "Linux":
+            raise NotImplementedError
+
+        f = open("/proc/net/route")
+        route_table = f.readlines()
+        f.close()
+        #toss out header
+        route_table.pop(0)
+
+        if not route_table:
+            raise exceptions.TunnelNotDefaultRouteError()
+
+        line = route_table.pop(0)
+        iface, destination = line.split('\t')[0:2]
+        if not destination == '00000000' or not iface == 'tun0':
+            raise exceptions.TunnelNotDefaultRouteError()
+
+    def get_default_interface_gateway(self):
+        """only impletemented for linux so far."""
+        if not platform.system() == "Linux":
+            raise NotImplementedError
+
+        # XXX use psutil
+        f = open("/proc/net/route")
+        route_table = f.readlines()
+        f.close()
+        #toss out header
+        route_table.pop(0)
+
+        default_iface = None
+        gateway = None
+        while route_table:
+            line = route_table.pop(0)
+            iface, destination, gateway = line.split('\t')[0:3]
+            if destination == '00000000':
+                default_iface = iface
+                break
+
+        if not default_iface:
+            raise exceptions.NoDefaultInterfaceFoundError
+
+        if default_iface not in netifaces.interfaces():
+            raise exceptions.InterfaceNotFoundError
+
+        return default_iface, gateway
+
+    def ping_gateway(self, gateway):
+        # TODO: Discuss how much packet loss (%) is acceptable.
+
+        # XXX -- validate gateway
+        # -- is it a valid ip? (there's something in util)
+        # -- is it a domain?
+        # -- can we resolve? -- raise NoDNSError if not.
+        packet_loss = ping.quiet_ping(gateway)[0]
+        if packet_loss > constants.MAX_ICMP_PACKET_LOSS:
+            raise exceptions.NoConnectionToGateway
+
+     # XXX check for name resolution servers
+     # dunno what's the best way to do this...
+     # check for etc/resolv entries or similar?
+     # just try to resolve?
+     # is there something in psutil?
+
+     # def check_name_resolution(self):
+     #     pass
diff --git a/src/leap/base/constants.py b/src/leap/base/constants.py
index 48a18dc3..f7be8d98 100644
--- a/src/leap/base/constants.py
+++ b/src/leap/base/constants.py
@@ -28,3 +28,5 @@ DEFAULT_PROVIDER_DEFINITION = {
     u'version': u'0.1.0'}
 
 MAX_ICMP_PACKET_LOSS = 10
+
+ROUTE_CHECK_INTERVAL = 10
diff --git a/src/leap/base/exceptions.py b/src/leap/base/exceptions.py
index 9c4aa77b..f12a49d5 100644
--- a/src/leap/base/exceptions.py
+++ b/src/leap/base/exceptions.py
@@ -1,6 +1,72 @@
+"""
+Exception attributes and their meaning/uses
+-------------------------------------------
+
+* critical:    if True, will abort execution prematurely,
+               after attempting any cleaning
+               action.
+
+* failfirst:   breaks any error_check loop that is examining
+               the error queue.
+
+* message:     the message that will be used in the __repr__ of the exception.
+
+* usermessage: the message that will be passed to user in ErrorDialogs
+               in Qt-land.
+"""
+
+
+class LeapException(Exception):
+    """
+    base LeapClient exception
+    sets some parameters that we will check
+    during error checking routines
+    """
+    critical = False
+    failfirst = False
+    warning = False
+
+
+class CriticalError(LeapException):
+    """
+    we cannot do anything about it
+    """
+    critical = True
+    failfirst = True
+
+
+# In use ???
+# don't thing so. purge if not...
+
 class MissingConfigFileError(Exception):
     pass
 
 
 class ImproperlyConfigured(Exception):
     pass
+
+
+class NoDefaultInterfaceFoundError(LeapException):
+    message = "no default interface found"
+    usermessage = "Looks like your computer is not connected to the internet"
+
+
+class InterfaceNotFoundError(LeapException):
+    # XXX should take iface arg on init maybe?
+    message = "interface not found"
+
+
+class NoConnectionToGateway(CriticalError):
+    message = "no connection to gateway"
+    usermessage = "Looks like there are problems with your internet connection"
+
+
+class NoInternetConnection(CriticalError):
+    message = "No Internet connection found"
+    usermessage = "It looks like there is no internet connection."
+    # and now we try to connect to our web to troubleshoot LOL :P
+
+
+class TunnelNotDefaultRouteError(CriticalError):
+    message = "Tunnel connection dissapeared. VPN down?"
+    usermessage = "The Encrypted Connection was lost. Shutting down..."
diff --git a/src/leap/base/network.py b/src/leap/base/network.py
new file mode 100644
index 00000000..e90139c4
--- /dev/null
+++ b/src/leap/base/network.py
@@ -0,0 +1,80 @@
+# -*- coding: utf-8 -*-
+from __future__ import (print_function)
+import logging
+import threading
+
+from leap.base.checks import LeapNetworkChecker
+from leap.base.constants import ROUTE_CHECK_INTERVAL
+from leap.base.exceptions import TunnelNotDefaultRouteError
+from leap.util.coroutines import (launch_thread, process_events)
+
+from time import sleep
+
+logger = logging.getLogger(name=__name__)
+
+
+class NetworkCheckerThread(object):
+    """
+    Manages network checking thread that makes sure we have a working network
+    connection.
+    """
+    def __init__(self, *args, **kwargs):
+        self.status_signals = kwargs.pop('status_signals', None)
+        #self.watcher_cb = kwargs.pop('status_signals', None)
+        self.error_cb = kwargs.pop(
+            'error_cb',
+            lambda exc: logger.error("%s", exc.message))
+        self.shutdown = threading.Event()
+
+        # XXX get provider_gateway and pass it to checker
+        # see in eip.config for function
+        # #718
+        self.checker = LeapNetworkChecker()
+
+    def start(self):
+        self.process_handle = self._launch_recurrent_network_checks(
+            (self.error_cb,))
+
+    def stop(self):
+        self.shutdown.set()
+        logger.debug("network checked stopped.")
+
+    def run_checks(self):
+        pass
+
+    #private methods
+
+    #here all the observers in fail_callbacks expect one positional argument,
+    #which is exception so we can try by passing a lambda with logger to
+    #check it works.
+    def _network_checks_thread(self, fail_callbacks):
+        #TODO: replace this with waiting for a signal from openvpn
+        while True:
+            try:
+                self.checker.check_tunnel_default_interface()
+                break
+            except TunnelNotDefaultRouteError:
+                # XXX ??? why do we sleep here???
+                sleep(1)
+
+        fail_observer_dict = dict(((
+            observer,
+            process_events(observer)) for observer in fail_callbacks))
+        while not self.shutdown.is_set():
+            try:
+                self.checker.check_tunnel_default_interface()
+                self.checker.check_internet_connection()
+                sleep(ROUTE_CHECK_INTERVAL)
+            except Exception as exc:
+                for obs in fail_observer_dict:
+                    fail_observer_dict[obs].send(exc)
+                sleep(ROUTE_CHECK_INTERVAL)
+        #reset event
+        self.shutdown.clear()
+
+    def _launch_recurrent_network_checks(self, fail_callbacks):
+        #we need to wrap the fail callback in a tuple
+        watcher = launch_thread(
+            self._network_checks_thread,
+            (fail_callbacks,))
+        return watcher
diff --git a/src/leap/base/tests/test_checks.py b/src/leap/base/tests/test_checks.py
new file mode 100644
index 00000000..bec09ce6
--- /dev/null
+++ b/src/leap/base/tests/test_checks.py
@@ -0,0 +1,117 @@
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
+import os
+
+from mock import (patch, Mock)
+from StringIO import StringIO
+
+import ping
+import requests
+
+from leap.base import checks
+from leap.base import exceptions
+from leap.testing.basetest import BaseLeapTest
+
+_uid = os.getuid()
+
+
+class LeapNetworkCheckTest(BaseLeapTest):
+    __name__ = "leap_network_check_tests"
+
+    def setUp(self):
+        pass
+
+    def tearDown(self):
+        pass
+
+    def test_checker_should_implement_check_methods(self):
+        checker = checks.LeapNetworkChecker()
+
+        self.assertTrue(hasattr(checker, "check_internet_connection"),
+                        "missing meth")
+        self.assertTrue(hasattr(checker, "check_tunnel_default_interface"),
+                        "missing meth")
+        self.assertTrue(hasattr(checker, "is_internet_up"),
+                        "missing meth")
+        self.assertTrue(hasattr(checker, "ping_gateway"),
+                        "missing meth")
+
+    def test_checker_should_actually_call_all_tests(self):
+        checker = checks.LeapNetworkChecker()
+
+        mc = Mock()
+        checker.run_all(checker=mc)
+        self.assertTrue(mc.check_internet_connection.called, "not called")
+        self.assertTrue(mc.check_tunnel_default_interface.called, "not called")
+        self.assertTrue(mc.ping_gateway.called, "not called")
+        self.assertTrue(mc.is_internet_up.called, "not called")
+
+    def test_get_default_interface_no_interface(self):
+        checker = checks.LeapNetworkChecker()
+        with patch('leap.base.checks.open', create=True) as mock_open:
+            with self.assertRaises(exceptions.NoDefaultInterfaceFoundError):
+                mock_open.return_value = StringIO(
+                    "Iface\tDestination Gateway\t"
+                    "Flags\tRefCntd\tUse\tMetric\t"
+                    "Mask\tMTU\tWindow\tIRTT")
+                checker.get_default_interface_gateway()
+
+    def test_check_tunnel_default_interface(self):
+        checker = checks.LeapNetworkChecker()
+        with patch('leap.base.checks.open', create=True) as mock_open:
+            with self.assertRaises(exceptions.TunnelNotDefaultRouteError):
+                mock_open.return_value = StringIO(
+                    "Iface\tDestination Gateway\t"
+                    "Flags\tRefCntd\tUse\tMetric\t"
+                    "Mask\tMTU\tWindow\tIRTT")
+                checker.check_tunnel_default_interface()
+
+        with patch('leap.base.checks.open', create=True) as mock_open:
+            with self.assertRaises(exceptions.TunnelNotDefaultRouteError):
+                mock_open.return_value = StringIO(
+                    "Iface\tDestination Gateway\t"
+                    "Flags\tRefCntd\tUse\tMetric\t"
+                    "Mask\tMTU\tWindow\tIRTT\n"
+                    "wlan0\t00000000\t0102A8C0\t"
+                    "0003\t0\t0\t0\t00000000\t0\t0\t0")
+                checker.check_tunnel_default_interface()
+
+        with patch('leap.base.checks.open', create=True) as mock_open:
+            mock_open.return_value = StringIO(
+                "Iface\tDestination Gateway\t"
+                "Flags\tRefCntd\tUse\tMetric\t"
+                "Mask\tMTU\tWindow\tIRTT\n"
+                "tun0\t00000000\t01002A0A\t0003\t0\t0\t0\t00000080\t0\t0\t0")
+            checker.check_tunnel_default_interface()
+
+    def test_ping_gateway_fail(self):
+        checker = checks.LeapNetworkChecker()
+        with patch.object(ping, "quiet_ping") as mocked_ping:
+            with self.assertRaises(exceptions.NoConnectionToGateway):
+                mocked_ping.return_value = [11, "", ""]
+                checker.ping_gateway("4.2.2.2")
+
+    def test_check_internet_connection_failures(self):
+        checker = checks.LeapNetworkChecker()
+        with patch.object(requests, "get") as mocked_get:
+            mocked_get.side_effect = requests.HTTPError
+            with self.assertRaises(exceptions.NoInternetConnection):
+                checker.check_internet_connection()
+
+        with patch.object(requests, "get") as mocked_get:
+            mocked_get.side_effect = requests.RequestException
+            with self.assertRaises(exceptions.NoInternetConnection):
+                checker.check_internet_connection()
+
+        #TODO: Mock possible errors that can be raised by is_internet_up
+        with patch.object(requests, "get") as mocked_get:
+            mocked_get.side_effect = requests.ConnectionError
+            with self.assertRaises(exceptions.NoInternetConnection):
+                checker.check_internet_connection()
+
+    @unittest.skipUnless(_uid == 0, "root only")
+    def test_ping_gateway(self):
+        checker = checks.LeapNetworkChecker()
+        checker.ping_gateway("4.2.2.2")