VPN: reset legacy VPN when resetting IPv4 addresses.

Currently legacy VPN only works on IPv4, and it should always
turn down when the addresses are changed. It assumed that the
interface will be brought down and up, so the event can be
detected via interfaceStatusChanged(). However, the assumption
was incorrect and the event is actually driver-dependent. To
fix this issue, ConnectivityService now tells VPN that the
interface is down when resetting IPv4 addresses.

Change-Id: I76d15e56552d86635c5b274ca980be5da905a6fb

2 files changed, 11 insertions, 3 deletions

diff --git a/services/java/com/android/server/ConnectivityService.java b/services/java/com/android/server/ConnectivityService.java
index a506636..81dc1a8 100644
--- a/services/java/com/android/server/ConnectivityService.java
+++ b/services/java/com/android/server/ConnectivityService.java
@@ -1780,14 +1780,20 @@ public class ConnectivityService extends IConnectivityManager.Stub {
         mCurrentLinkProperties[netType] = newLp;
         boolean resetDns = updateRoutes(newLp, curLp, mNetConfigs[netType].isDefault());
 
-        if (doReset || resetMask != 0 || resetDns) {
+        if (resetMask != 0 || resetDns) {
             LinkProperties linkProperties = mNetTrackers[netType].getLinkProperties();
             if (linkProperties != null) {
                 String iface = linkProperties.getInterfaceName();
                 if (TextUtils.isEmpty(iface) == false) {
-                    if (doReset || resetMask != 0) {
+                    if (resetMask != 0) {
                         if (DBG) log("resetConnections(" + iface + ", " + resetMask + ")");
                         NetworkUtils.resetConnections(iface, resetMask);
+
+                        // Tell VPN the interface is down. It is a temporary
+                        // but effective fix to make VPN aware of the change.
+                        if ((resetMask & NetworkUtils.RESET_IPV4_ADDRESSES) != 0) {
+                            mVpn.interfaceStatusChanged(iface, false);
+                        }
                     }
                     if (resetDns) {
                         if (DBG) log("resetting DNS cache for " + iface);
diff --git a/services/java/com/android/server/connectivity/Vpn.java b/services/java/com/android/server/connectivity/Vpn.java
index d9da92c..6b65e07 100644
--- a/services/java/com/android/server/connectivity/Vpn.java
+++ b/services/java/com/android/server/connectivity/Vpn.java
@@ -265,7 +265,6 @@ public class Vpn extends INetworkManagementEventObserver.Stub {
     // INetworkManagementEventObserver.Stub
     @Override
     public void interfaceLinkStateChanged(String interfaze, boolean up) {
-        interfaceStatusChanged(interfaze, up);
     }
 
     // INetworkManagementEventObserver.Stub
@@ -280,6 +279,9 @@ public class Vpn extends INetworkManagementEventObserver.Stub {
             if (mConnection != null) {
                 mContext.unbindService(mConnection);
                 mConnection = null;
+            } else if (mLegacyVpnRunner != null) {
+                mLegacyVpnRunner.exit();
+                mLegacyVpnRunner = null;
             }
         }
     }