Must let you understand what Netlink is

Both the kernel netlink socket and the user space netlink socket will call the following function to create a sock

/*
	调用流程:
	 0xffffff80089c7790 : __netlink_create+0x0/0xe4 [kernel]
	 0xffffff80089c7d70 : netlink_create+0x1ec/0x26c [kernel]
	 0xffffff8008989d50 : __sock_create+0x11c/0x180 [kernel]
	 0xffffff8008989e00 : sock_create+0x4c/0x5c [kernel]
	 0xffffff800898ad6c : SyS_socket+0x48/0xd0 [kernel]
	 0xffffff8008082f30 : el0_svc_naked+0x24/0x28 [kernel]
	 0x0 (inexact)
*/
static int __netlink_create(struct net *net, 
									struct socket *sock,
			    					struct mutex *cb_mutex, 
			    					int protocol,
			    					int kern)
{
    
    
	....
	/*
		用户空间调用 bind() connect() .....
		会在这里进行响应:
		
		static const struct proto_ops netlink_ops = {
    
    
		.family =	PF_NETLINK,
		.owner =	THIS_MODULE,
		.release =	netlink_release,
		.bind =		netlink_bind,
		...
		.shutdown =	sock_no_shutdown,
		.setsockopt =	netlink_setsockopt,
	};
	*/
	sock->ops = &netlink_ops;
}