Make disconnect due to NUD_FAILURE optional

Provide a special dumpsys parameter to inhibit disconnect due to IP
connectivity failure.  Running "dumpsys wifi set-ipreach-disconnect disabled"
will enable this functionality.  This will be useful for performing tests
where we would like to understand what happens if we stay online after
a NUD_FAILURE.

Bug: 32331899
Test: run "adb shell dumpsys wifi set-ipreach-disconnect" on DUT

Change-Id: I12474671e22871c4e1c2f755af2a1cac8f652f5b

2 files changed, 37 insertions, 2 deletions

diff --git a/service/java/com/android/server/wifi/WifiServiceImpl.java b/service/java/com/android/server/wifi/WifiServiceImpl.java
index b71bf39ae..3539cc249 100644
--- a/service/java/com/android/server/wifi/WifiServiceImpl.java
+++ b/service/java/com/android/server/wifi/WifiServiceImpl.java
@@ -119,6 +119,11 @@ public class WifiServiceImpl extends IWifiManager.Stub {
     private static final boolean DBG = true;
     private static final boolean VDBG = false;
 
+    // Dumpsys argument to enable/disable disconnect on IP reachability failures.
+    private static final String DUMP_ARG_SET_IPREACH_DISCONNECT = "set-ipreach-disconnect";
+    private static final String DUMP_ARG_SET_IPREACH_DISCONNECT_ENABLED = "enabled";
+    private static final String DUMP_ARG_SET_IPREACH_DISCONNECT_DISABLED = "disabled";
+
     final WifiStateMachine mWifiStateMachine;
 
     private final Context mContext;
@@ -1396,6 +1401,17 @@ public class WifiServiceImpl extends IWifiManager.Stub {
             String[] ipManagerArgs = new String[args.length - 1];
             System.arraycopy(args, 1, ipManagerArgs, 0, ipManagerArgs.length);
             mWifiStateMachine.dumpIpManager(fd, pw, ipManagerArgs);
+        } else if (args.length > 0 && DUMP_ARG_SET_IPREACH_DISCONNECT.equals(args[0])) {
+            if (args.length > 1) {
+                if (DUMP_ARG_SET_IPREACH_DISCONNECT_ENABLED.equals(args[1])) {
+                    mWifiStateMachine.setIpReachabilityDisconnectEnabled(true);
+                } else if (DUMP_ARG_SET_IPREACH_DISCONNECT_DISABLED.equals(args[1])) {
+                    mWifiStateMachine.setIpReachabilityDisconnectEnabled(false);
+                }
+            }
+            pw.println("IPREACH_DISCONNECT state is "
+                    + mWifiStateMachine.getIpReachabilityDisconnectEnabled());
+            return;
         } else {
             pw.println("Wi-Fi is " + mWifiStateMachine.syncGetWifiStateByName());
             pw.println("Stay-awake conditions: " +
diff --git a/service/java/com/android/server/wifi/WifiStateMachine.java b/service/java/com/android/server/wifi/WifiStateMachine.java
index 859bbb241..8e5d904dd 100644
--- a/service/java/com/android/server/wifi/WifiStateMachine.java
+++ b/service/java/com/android/server/wifi/WifiStateMachine.java
@@ -231,6 +231,7 @@ public class WifiStateMachine extends StateMachine implements WifiNative.WifiRss
     private boolean mIsLinkDebouncing = false;
     private final StateMachineDeathRecipient mDeathRecipient =
             new StateMachineDeathRecipient(this, CMD_CLIENT_INTERFACE_BINDER_DEATH);
+    private boolean mIpReachabilityDisconnectEnabled = true;
 
     @Override
     public void onRssiThresholdBreached(byte curRssi) {
@@ -5612,8 +5613,12 @@ public class WifiStateMachine extends StateMachine implements WifiNative.WifiRss
                     break;
                 case CMD_IP_REACHABILITY_LOST:
                     if (mVerboseLoggingEnabled && message.obj != null) log((String) message.obj);
-                    handleIpReachabilityLost();
-                    transitionTo(mDisconnectingState);
+                    if (mIpReachabilityDisconnectEnabled) {
+                        handleIpReachabilityLost();
+                        transitionTo(mDisconnectingState);
+                    } else {
+                        logd("CMD_IP_REACHABILITY_LOST but disconnect disabled -- ignore");
+                    }
                     break;
                 case CMD_DISCONNECT:
                     mWifiNative.disconnect();
@@ -6919,4 +6924,18 @@ public class WifiStateMachine extends StateMachine implements WifiNative.WifiRss
     private boolean hasConnectionRequests() {
         return mConnectionReqCount > 0 || mUntrustedReqCount > 0;
     }
+
+    /**
+     * Returns whether CMD_IP_REACHABILITY_LOST events should trigger disconnects.
+     */
+    public boolean getIpReachabilityDisconnectEnabled() {
+        return mIpReachabilityDisconnectEnabled;
+    }
+
+    /**
+     * Sets whether CMD_IP_REACHABILITY_LOST events should trigger disconnects.
+     */
+    public void setIpReachabilityDisconnectEnabled(boolean enabled) {
+        mIpReachabilityDisconnectEnabled = enabled;
+    }
 }