Merge change 6823

* changes:
  wifi: Keep the WLAN network interface up whenever wifi is enabled.

core/java/android/net/NetworkUtils.java

@@ -25,6 +25,9 @@ import java.net.UnknownHostException;
  * {@hide}
  */
 public class NetworkUtils {
+    /** Bring the named network interface up. */
+    public native static int enableInterface(String interfaceName);
+
     /** Bring the named network interface down. */
     public native static int disableInterface(String interfaceName);
 

core/jni/android_net_NetUtils.cpp

@@ -23,6 +23,7 @@
 #include <arpa/inet.h>
 
 extern "C" {
+int ifc_enable(const char *ifname);
 int ifc_disable(const char *ifname);
 int ifc_add_host_route(const char *ifname, uint32_t addr);
 int ifc_remove_host_routes(const char *ifname);
@@ -66,6 +67,16 @@ static struct fieldIds {
     jfieldID leaseDuration;
 } dhcpInfoFieldIds;
 
+static jint android_net_utils_enableInterface(JNIEnv* env, jobject clazz, jstring ifname)
+{
+    int result;
+
+    const char *nameStr = env->GetStringUTFChars(ifname, NULL);
+    result = ::ifc_enable(nameStr);
+    env->ReleaseStringUTFChars(ifname, nameStr);
+    return (jint)result;
+}
+
 static jint android_net_utils_disableInterface(JNIEnv* env, jobject clazz, jstring ifname)
 {
     int result;
@@ -209,6 +220,7 @@ static jboolean android_net_utils_configureInterface(JNIEnv* env,
 static JNINativeMethod gNetworkUtilMethods[] = {
     /* name, signature, funcPtr */
 
+    { "enableInterface", "(Ljava/lang/String;)I",  (void *)android_net_utils_enableInterface },
     { "disableInterface", "(Ljava/lang/String;)I",  (void *)android_net_utils_disableInterface },
     { "addHostRoute", "(Ljava/lang/String;I)I",  (void *)android_net_utils_addHostRoute },
     { "removeHostRoutes", "(Ljava/lang/String;)I",  (void *)android_net_utils_removeHostRoutes },

services/java/com/android/server/WifiService.java

@@ -41,6 +41,7 @@ import android.net.wifi.WifiConfiguration;
 import android.net.wifi.SupplicantState;
 import android.net.NetworkStateTracker;
 import android.net.DhcpInfo;
+import android.net.NetworkUtils;
 import android.os.Binder;
 import android.os.Handler;
 import android.os.HandlerThread;
@@ -344,7 +345,7 @@ public class WifiService extends IWifiManager.Stub {
             }
 
             // We must reset the interface before we unload the driver
-            mWifiStateTracker.resetInterface();
+            mWifiStateTracker.resetInterface(false);
 
             if (!WifiNative.unloadDriver()) {
                 Log.e(TAG, "Failed to unload Wi-Fi driver.");
@@ -1045,7 +1046,13 @@ public class WifiService extends IWifiManager.Stub {
         enforceChangePermission();
 
         synchronized (mWifiStateTracker) {
-            return WifiNative.enableNetworkCommand(netId, disableOthers);
+            String ifname = mWifiStateTracker.getInterfaceName();
+            NetworkUtils.enableInterface(ifname);
+            boolean result = WifiNative.enableNetworkCommand(netId, disableOthers);
+            if (!result) {
+                NetworkUtils.disableInterface(ifname);
+            }
+            return result;
         }
     }
 

wifi/java/android/net/wifi/WifiStateTracker.java

@@ -377,6 +377,14 @@ public class WifiStateTracker extends NetworkStateTracker {
         return getNameServerList(sDnsPropNames);
     }
 
+    /**
+     * Return the name of our WLAN network interface.
+     * @return the name of our interface.
+     */
+    public String getInterfaceName() {
+        return mInterfaceName;
+    }
+
     /**
      * Return the system properties name associated with the tcp buffer sizes
      * for this network.
@@ -784,7 +792,7 @@ public class WifiStateTracker extends NetworkStateTracker {
                     WifiNative.closeSupplicantConnection();
                 }
                 if (died) {
-                    resetInterface();
+                    resetInterface(false);
                 }
                 // When supplicant dies, kill the DHCP thread
                 if (mDhcpTarget != null) {
@@ -1195,7 +1203,7 @@ public class WifiStateTracker extends NetworkStateTracker {
             cancelDisconnect();
         }
         mDisconnectExpected = false;
-        resetInterface();
+        resetInterface(true);
         setDetailedState(newState);
         sendNetworkStateChangeBroadcast(mLastBssid);
         mWifiInfo.setBSSID(null);
@@ -1208,7 +1216,7 @@ public class WifiStateTracker extends NetworkStateTracker {
      * Resets the Wi-Fi interface by clearing any state, resetting any sockets
      * using the interface, stopping DHCP, and disabling the interface.
      */
-    public void resetInterface() {
+    public void resetInterface(boolean reenable) {
         mHaveIpAddress = false;
         mObtainingIpAddress = false;
         mWifiInfo.setIpAddress(0);
@@ -1229,6 +1237,9 @@ public class WifiStateTracker extends NetworkStateTracker {
         }
         
         NetworkUtils.disableInterface(mInterfaceName);
+        if (reenable) {
+            NetworkUtils.enableInterface(mInterfaceName);
+        }
     }
 
     /**
@@ -1872,7 +1883,7 @@ public class WifiStateTracker extends NetworkStateTracker {
                         oDns2 != mDhcpInfo.dns2));
 
             if (changed) {
-                resetInterface();
+                resetInterface(true);
                 configureInterface();
                 if (mUseStaticIp) {
                     mTarget.sendEmptyMessage(EVENT_CONFIGURATION_CHANGED);