Android10.0 iptables uses IOemNetd to realize the function of app Internet whitelist

1 Introduction

In the 10.0 system rom customization development, in the product requirements of the netd network in the system, it will be required to set the whitelist function for the app to access the Internet. The iptables command
in liunx is also more important. Next, it will be implemented in the IOemNetd area. The relevant function of the white list of app Internet access is that
only one app can be allowed to access the Internet in the system, that is, other apps except this app cannot access the Internet, and finally implement the interface call in the framework custom service

2. iptables uses IOemNetd to realize the core class of app Internet whitelist function

system\netd\server\binder\com\android\internal\net\IOemNetd.aidl
system\netd\server\OemNetdListener.cpp
system\netd\server\OemNetdListener.h

3. Analysis and implementation of the core functions of iptables using IOemNetd to realize the whitelist function of app Internet access

In the android native system, iptables is very important in the network filtering packet module. Iptabels is a packet filtering firewall system integrated with the Linux kernel. Both linux and android include the function of Iptables.
Iptables facilitate better control of IP packet filtering and firewall configuration on a Linux system if the Linux system is connected to the Internet or a LAN, a server, or a proxy server that connects the LAN to the Internet.
Another important advantage of netfilter/iptables is that it gives the user complete control over firewall configuration and packet filtering. You can customize your own rules to meet your specific needs

The commonly used commands of iptables are as follows:
Command Description

-L --list <chain name> View iptables rule list
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