If you want to scan the interface list from kernel space you can do something like:

{
	struct device *dev;

	for (dev = dev_base; dev != NULL; dev = dev->next)
        {
		/* your code here */
		/* example */

		if (dev->family == AF_INET)
		{
			/* this is an inet device */
		}

		if (dev->type == ARPHRD_ETHER)
		{
			/* this is ethernet */
		}
	}
}

./Pedro.