[MAC rand] Avoid null Object of mac address

Bug: 140309663
Test: unit tests

Merged-In: I914a2678e62f1e2ef6dc1b358a76a306b9cc0cc4
Change-Id: Ibf281c5e25c21c17652d718c346c8b560aedcc72
(cherry picked from commit I914a2678e62f1e2ef6dc1b358a76a306b9cc0cc4)

2 files changed, 20 insertions, 3 deletions

diff --git a/service/java/com/android/server/wifi/ClientModeImpl.java b/service/java/com/android/server/wifi/ClientModeImpl.java
index b80371285..fa2f4a980 100644
--- a/service/java/com/android/server/wifi/ClientModeImpl.java
+++ b/service/java/com/android/server/wifi/ClientModeImpl.java
@@ -3380,12 +3380,14 @@ public class ClientModeImpl extends StateMachine {
             Log.e(TAG, "No config to change MAC address to");
             return;
         }
-        MacAddress currentMac = MacAddress.fromString(mWifiNative.getMacAddress(mInterfaceName));
+        String currentMacString = mWifiNative.getMacAddress(mInterfaceName);
+        MacAddress currentMac = currentMacString == null ? null :
+                MacAddress.fromString(currentMacString);
         MacAddress newMac = config.getOrCreateRandomizedMacAddress();
         mWifiConfigManager.setNetworkRandomizedMacAddress(config.networkId, newMac);
         if (!WifiConfiguration.isValidMacAddressForRandomization(newMac)) {
             Log.wtf(TAG, "Config generated an invalid MAC address");
-        } else if (currentMac.equals(newMac)) {
+        } else if (newMac.equals(currentMac)) {
             Log.d(TAG, "No changes in MAC address");
         } else {
             mWifiMetrics.logStaEvent(StaEvent.TYPE_MAC_CHANGE, config);
@@ -3393,7 +3395,7 @@ public class ClientModeImpl extends StateMachine {
                     mWifiNative.setMacAddress(mInterfaceName, newMac);
             Log.d(TAG, "ConnectedMacRandomization SSID(" + config.getPrintableSsid()
                     + "). setMacAddress(" + newMac.toString() + ") from "
-                    + currentMac.toString() + " = " + setMacSuccess);
+                    + currentMacString + " = " + setMacSuccess);
         }
     }
 
diff --git a/tests/wifitests/src/com/android/server/wifi/ClientModeImplTest.java b/tests/wifitests/src/com/android/server/wifi/ClientModeImplTest.java
index 7896a8f0b..f0e9d2c10 100644
--- a/tests/wifitests/src/com/android/server/wifi/ClientModeImplTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/ClientModeImplTest.java
@@ -2748,6 +2748,21 @@ public class ClientModeImplTest {
     }
 
     /**
+     * Verify that we don't crash when WifiNative returns null as the current MAC address.
+     * @throws Exception
+     */
+    @Test
+    public void testMacRandomizationWifiNativeReturningNull() throws Exception {
+        when(mWifiNative.getMacAddress(anyString())).thenReturn(null);
+        initializeAndAddNetworkAndVerifySuccess();
+        assertEquals(ClientModeImpl.CONNECT_MODE, mCmi.getOperationalModeForTest());
+        assertEquals(WifiManager.WIFI_STATE_ENABLED, mCmi.syncGetWifiState());
+
+        connect();
+        verify(mWifiNative).setMacAddress(WIFI_IFACE_NAME, TEST_LOCAL_MAC_ADDRESS);
+    }
+
+    /**
      * Verifies that CMD_START_CONNECT make WifiDiagnostics report
      * CONNECTION_EVENT_STARTED
      * @throws Exception