在Android中只有一个有效的网络接口 -- wi-fi 领域 和 networking 领域 和 connection-issues 领域 和 mobile-data 领域 和 mobile-network 领域 android 相关 的问题

I was looking into the network configurations in Android devices. Android makes WI-FI as the default network preference. And I noticed only one network interface can be active at a time in Android. Even ifconfig shows both wi-fi and rmnet_data0 interfaces UP, the routing table has routing rules applied for only one interface.

The rmnet_data0 interface doesn't have RUNNING state when wi-fi is ON. Can you please point me to which file in AOSP file that this restriction implementation has been made (like register only one net_device)? In ConnectivityManager.java file I saw that TYPE_WI-FI was made the default interface, but I could not find how and where they register and unregister network interfaces when WI-FI is present or not.