[RTT] Add NPE checks for invalid MAC addresses from Aware

RTT requests for Aware peers may use PeerHandles. The RTT service
queries the Aware service for their corresponding MAC addresses. In
some corner cases, e.g. the Aware peer just disappeared, a null MAC
address may be returned.

This was not handled, resulting in an NPE.

Bug: 111646773
Test: new unit test added, passes
Change-Id: I7d7c37322848fe7e7dd4f9f412f1e1339321e9a8

2 files changed, 17 insertions, 6 deletions

diff --git a/service/java/com/android/server/wifi/rtt/RttServiceImpl.java b/service/java/com/android/server/wifi/rtt/RttServiceImpl.java
index 75e75aa0f..258bdb67f 100644
--- a/service/java/com/android/server/wifi/rtt/RttServiceImpl.java
+++ b/service/java/com/android/server/wifi/rtt/RttServiceImpl.java
@@ -1016,8 +1016,14 @@ public class RttServiceImpl extends IWifiRttManager.Stub {
             RangingRequest.Builder newRequestBuilder = new RangingRequest.Builder();
             for (ResponderConfig rttPeer : request.request.mRttPeers) {
                 if (rttPeer.peerHandle != null && rttPeer.macAddress == null) {
+                    byte[] mac = peerIdToMacMap.get(rttPeer.peerHandle.peerId);
+                    if (mac == null || mac.length != 6) {
+                        Log.e(TAG, "processReceivedAwarePeerMacAddresses: received an invalid MAC "
+                                + "address for peerId=" + rttPeer.peerHandle.peerId);
+                        continue;
+                    }
                     newRequestBuilder.addResponder(new ResponderConfig(
-                            MacAddress.fromBytes(peerIdToMacMap.get(rttPeer.peerHandle.peerId)),
+                            MacAddress.fromBytes(mac),
                             rttPeer.peerHandle, rttPeer.responderType, rttPeer.supports80211mc,
                             rttPeer.channelWidth, rttPeer.frequency, rttPeer.centerFreq0,
                             rttPeer.centerFreq1, rttPeer.preamble));
diff --git a/tests/wifitests/src/com/android/server/wifi/rtt/RttServiceImplTest.java b/tests/wifitests/src/com/android/server/wifi/rtt/RttServiceImplTest.java
index d1c1b028b..e1f35239f 100644
--- a/tests/wifitests/src/com/android/server/wifi/rtt/RttServiceImplTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/rtt/RttServiceImplTest.java
@@ -305,13 +305,16 @@ public class RttServiceImplTest {
         RangingRequest request = RttTestUtils.getDummyRangingRequest((byte) 0xA);
         PeerHandle peerHandle1 = new PeerHandle(1022);
         PeerHandle peerHandle2 = new PeerHandle(1023);
+        PeerHandle peerHandle3 = new PeerHandle(1024);
         request.mRttPeers.add(ResponderConfig.fromWifiAwarePeerHandleWithDefaults(peerHandle1));
         request.mRttPeers.add(ResponderConfig.fromWifiAwarePeerHandleWithDefaults(peerHandle2));
+        request.mRttPeers.add(ResponderConfig.fromWifiAwarePeerHandleWithDefaults(peerHandle3));
         Map<Integer, MacAddress> peerHandleToMacMap = new HashMap<>();
         MacAddress macAwarePeer1 = MacAddress.fromString("AA:BB:CC:DD:EE:FF");
         MacAddress macAwarePeer2 = MacAddress.fromString("BB:BB:BB:EE:EE:EE");
         peerHandleToMacMap.put(peerHandle1.peerId, macAwarePeer1);
         peerHandleToMacMap.put(peerHandle2.peerId, macAwarePeer2);
+        peerHandleToMacMap.put(peerHandle3.peerId, null); // bad answer from Aware (expired?)
 
         AwareTranslatePeerHandlesToMac answer = new AwareTranslatePeerHandlesToMac(mDefaultUid,
                 peerHandleToMacMap);
@@ -327,7 +330,8 @@ public class RttServiceImplTest {
 
         RangingRequest finalRequest = mRequestCaptor.getValue();
         assertNotEquals("Request to native is not null", null, finalRequest);
-        assertEquals("Size of request", request.mRttPeers.size(), finalRequest.mRttPeers.size());
+        assertEquals("Size of request", request.mRttPeers.size() - 1,
+                finalRequest.mRttPeers.size());
         assertEquals("Aware peer 1 MAC", macAwarePeer1,
                 finalRequest.mRttPeers.get(finalRequest.mRttPeers.size() - 2).macAddress);
         assertEquals("Aware peer 2 MAC", macAwarePeer2,
@@ -1452,12 +1456,13 @@ public class RttServiceImplTest {
 
             Map<Integer, byte[]> result = new HashMap<>();
             for (Integer peerId: peerIds) {
-                byte[] mac = mPeerIdToMacMap.get(peerId).toByteArray();
-                if (mac == null) {
-                    continue;
+                byte[] macBytes = null;
+                MacAddress macAddr = mPeerIdToMacMap.get(peerId);
+                if (macAddr != null) {
+                    macBytes = macAddr.toByteArray();
                 }
 
-                result.put(peerId, mac);
+                result.put(peerId, macBytes);
             }
 
             try {