Add a route backwards from the DUT to the test host

server/site_wifitest.py

Index: server/site_wifitest.py
diff --git a/server/site_wifitest.py b/server/site_wifitest.py
index e05f303334b749fa3395df7f5d313fd017f42114..1274e36c3d79d9cd59ec8eb5b9a86aad9be3fa4d 100644
--- a/server/site_wifitest.py
+++ b/server/site_wifitest.py
@@ -9,6 +9,7 @@ from autotest_lib.server import site_bsd_router
 from autotest_lib.server import site_linux_router
 from autotest_lib.server import site_linux_server
 from autotest_lib.server import site_host_attributes
+from autotest_lib.server import site_host_route
 from autotest_lib.server import site_eap_certs
 from autotest_lib.server import test
 from autotest_lib.client.common_lib import error
@@ -154,6 +155,7 @@ class WiFiTest(object):
         self.__client_discover_commands(client)
         self.profile_save({})
         self.firewall_rules = []
+        self.host_route_args = {}
 
         # interface name on client
         self.client_wlanif = client.get('wlandev',
@@ -1230,6 +1232,10 @@ class WiFiTest(object):
         # Must get 'ca_certificate', 'client-certificate' and 'client-key'.
         cert_pathnames = params.get('files', {})
 
+        # Set up a host route on the DUT so that the VPN doesn't prevent us

[thutt, 2011/04/01 21:43:06]

Can you make this comment more clear?  It's rather convoluted at written.

+        # from having IP traffic from it return to us

[thutt, 2011/04/01 21:43:06]

This comment too.
In my implementation, I split the if/elif starting at line 1239 into an if/if.  

I put the route addition between lines 1240 and 1240.  It's a negligible amount
of time, but at least you won't end up creating the route for error cases.

Conversely, the route is removed only if there is an actual VPN kind in
vpn_client_kill.

Feel free to ignore.

[Paul Stewart, 2011/04/01 21:52:45]

Feel free to move it where you'd like, and change the comment as well.  This is
just a suggestion, and I understand you're still actively working on this.

+        __add_host_route(self.client)
+
         if self.vpn_kind is None:
             raise error.TestFail('No VPN kind specified for this test.')
         elif self.vpn_kind == 'openvpn':
@@ -1268,6 +1274,28 @@ class WiFiTest(object):
                                      'for VPN kind (%s)' % self.vpn_kind)
             self.vpn_kind = None
 
+        __del_host_route(self.client)
+
+    def __add_host_route(self, host):
+        # What is the local address we use to get to the test host?
+        local_ip = site_host_route.LocalHostRoute(host.ip).route_info["src"]
+
+        # How does the test host currently get to this local address?
+        host_route = site_host_route.RemoteHostRoute(host, local_ip).route_info
+
+        # Flatten the returned dict into a single string
+        route_args = " ".join(" ".join(x) for x in host_route.iteritems())
+
+        self.host_route_args[host.ip] = "%s %s" % (local_ip, route_args)
+        host.run("ip route add %s" % self.host_route_args[host.ip])
+
+    def __del_host_route(self, host):
+        if host.ip not in self.host_route_args:
+            return
+
+        host.run("ip route del %s" % self.host_route_args.pop(host.ip))
+
+
 class HelperThread(threading.Thread):
     # Class that wraps a ping command in a thread so it can run in the bg.
     def __init__(self, client, cmd):