commit ec180d57f14e883710729d2c3f47e4d02b3850a0
author Hugo Benichi <hugobenichi@google.com> Fri Feb 03 14:18:44 2017 +0900
committer Hugo Benichi <hugobenichi@google.com> Tue Feb 14 16:01:40 2017 +0900
tree 5174355da17156a3c3fa3b5d0357b809cd4c6992
parent 50068e5fdd30550f0f685b987018628ee7390904

ConnectivityManager: fix potential NPE

ConnectivityManager static sCallbackHandler is referenced and directly
used in a way that is not ensuring its proper initialization.

This patch fixes this potential NPE by using getHandler() instead.

Also this patch changes sendRequestForNetwork's signature to only accept
the subtype CallbackHandler instead of Handler: without using
CallbackHandler the NetworkCallbacks are not triggered properly and
bookkeeping of sCallbacks does not happen. sendRequestForNetwork's
signature now makes this explicit.

This step prepares the addition of overloaded versions of
registerNetworkCallback and cie that takes custom Handlers.

Test: build, flashed, manually checked connectivity
Change-Id: I52e8a2cb5075e7aef7b35e30c9845cacba927d13

core/java/android/net/ConnectivityManager.java

diff --git a/core/java/android/net/ConnectivityManager.java b/core/java/android/net/ConnectivityManager.java
index 82e3093..4885550 100644
--- a/core/java/android/net/ConnectivityManager.java
+++ b/core/java/android/net/ConnectivityManager.java
@@ -1432,8 +1432,9 @@
     private void sendExpireMsgForFeature(NetworkCapabilities netCap, int seqNum, int delay) {
         if (delay >= 0) {
             Log.d(TAG, "sending expire msg with seqNum " + seqNum + " and delay " + delay);
-            Message msg = sCallbackHandler.obtainMessage(EXPIRE_LEGACY_REQUEST, seqNum, 0, netCap);
-            sCallbackHandler.sendMessageDelayed(msg, delay);
+            CallbackHandler handler = getHandler();
+            Message msg = handler.obtainMessage(EXPIRE_LEGACY_REQUEST, seqNum, 0, netCap);
+            handler.sendMessageDelayed(msg, delay);
         }
     }
 
@@ -2868,19 +2869,19 @@
         }
     }
 
-    static final HashMap<NetworkRequest, NetworkCallback> sCallbacks = new HashMap<>();
-    static CallbackHandler sCallbackHandler;
+    private static final HashMap<NetworkRequest, NetworkCallback> sCallbacks = new HashMap<>();
+    private static CallbackHandler sCallbackHandler;
 
-    private final static int LISTEN  = 1;
-    private final static int REQUEST = 2;
+    private static final int LISTEN  = 1;
+    private static final int REQUEST = 2;
 
     private NetworkRequest sendRequestForNetwork(NetworkCapabilities need,
             NetworkCallback callback, int timeoutMs, int action, int legacyType) {
-        return sendRequestForNetwork(need, callback, getHandler(), timeoutMs, action, legacyType);
+        return sendRequestForNetwork(need, callback, timeoutMs, action, legacyType, getHandler());
     }
 
-    private NetworkRequest sendRequestForNetwork(NetworkCapabilities need,
-            NetworkCallback callback, Handler handler, int timeoutMs, int action, int legacyType) {
+    private NetworkRequest sendRequestForNetwork(NetworkCapabilities need, NetworkCallback callback,
+            int timeoutMs, int action, int legacyType, CallbackHandler handler) {
         if (callback == null) {
             throw new IllegalArgumentException("null NetworkCallback");
         }