WifiStateTracker: add support for overriding DCHP max retry count in an overlay

Bug: 5551068

Change-Id: I7817eeb1409af2056a63548104c3c64f93ee7def
Signed-off-by: Mike Lockwood <lockwood@google.com>

packages/SettingsProvider/res/values/defaults.xml

@@ -142,4 +142,8 @@
 
     <!-- Development settings -->
     <bool name="def_stay_on_while_plugged_in">false</bool>
+
+    <!-- Number of retries for connecting to DHCP.
+         Value here is the same as WifiStateMachine.DEFAULT_MAX_DHCP_RETRIES -->
+    <integer name="def_max_dhcp_retries">9</integer>
 </resources>

packages/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java

@@ -1565,6 +1565,9 @@ public class DatabaseHelper extends SQLiteOpenHelper {
 
             loadBooleanSetting(stmt, Settings.Secure.NETSTATS_ENABLED,
                     R.bool.def_netstats_enabled);
+
+            loadIntegerSetting(stmt, Settings.Secure.WIFI_MAX_DHCP_RETRY_COUNT,
+                    R.integer.def_max_dhcp_retries);
         } finally {
             if (stmt != null) stmt.close();
         }

wifi/java/android/net/wifi/WifiStateMachine.java

@@ -1742,7 +1742,9 @@ public class WifiStateMachine extends StateMachine {
          * If we've exceeded the maximum number of retries for DHCP
          * to a given network, disable the network
          */
-        if (++mReconnectCount > getMaxDhcpRetries()) {
+        int maxRetries = getMaxDhcpRetries();
+        // maxRetries == 0 means keep trying forever
+        if (maxRetries > 0 && ++mReconnectCount > maxRetries) {
             loge("Failed " +
                     mReconnectCount + " times, Disabling " + mLastNetworkId);
             WifiConfigStore.disableNetwork(mLastNetworkId,