commit 2ed7d4182af623b87d0f7144e8781e60463302a9
author Junyu Lai <junyulai@google.com> Fri Oct 07 16:52:21 2022 +0800
committer Junyu Lai <junyulai@google.com> Tue Oct 25 15:27:53 2022 +0800
tree 83d919ac0357ce7d9f7666246fca7fe89d1c3498
parent 3e7778805b069729c151e752ebacc46b457c5f59

Notify NetworkStats only when interfaces changed in updateLinkProperties

In ConnectivityService, updateLinkProperties calls NetworkStats
even though the ip address or interface name has not changed and
only the tcp buffer size has changed. This is noisy and could
be problematic when RAT change occurs frequently, since when
RAT changes tcp buffer size configuration also changes.

This CL also fixes a wrong nullability annotation where the oldLp
of updateLinkProperties could be null when updateNetworkInfo
is called.

Test: atest ConnectivityServiceTest#testStatsIfacesChanged
Fix: 232048480
Change-Id: Ic226eb4a8aa1f38cba293510813f1cb55f0ea658

service/src/com/android/server/ConnectivityService.java

diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index 93265e5..dfa132e 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -7435,7 +7435,7 @@
     }
 
     private void updateLinkProperties(NetworkAgentInfo networkAgent, @NonNull LinkProperties newLp,
-            @NonNull LinkProperties oldLp) {
+            @Nullable LinkProperties oldLp) {
         int netId = networkAgent.network.getNetId();
 
         // The NetworkAgent does not know whether clatd is running on its network or not, or whether
@@ -7487,7 +7487,13 @@
             }
             // Start or stop DNS64 detection and 464xlat according to network state.
             networkAgent.clatd.update();
-            notifyIfacesChangedForNetworkStats();
+            // Notify NSS when relevant events happened. Currently, NSS only cares about
+            // interface changed to update clat interfaces accounting.
+            final boolean interfacesChanged = oldLp == null
+                    || !Objects.equals(newLp.getAllInterfaceNames(), oldLp.getAllInterfaceNames());
+            if (interfacesChanged) {
+                notifyIfacesChangedForNetworkStats();
+            }
             networkAgent.networkMonitor().notifyLinkPropertiesChanged(
                     new LinkProperties(newLp, true /* parcelSensitiveFields */));
             notifyNetworkCallbacks(networkAgent, ConnectivityManager.CALLBACK_IP_CHANGED);
@@ -8246,7 +8252,8 @@
         }
     }
 
-    public void handleUpdateLinkProperties(NetworkAgentInfo nai, LinkProperties newLp) {
+    public void handleUpdateLinkProperties(@NonNull NetworkAgentInfo nai,
+            @NonNull LinkProperties newLp) {
         ensureRunningOnConnectivityServiceThread();
 
         if (!mNetworkAgentInfos.contains(nai)) {