oreore.c

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/security.h>

/* should we print out debug messages */
static int debug = 0;

module_param(debug, bool, 0600);
MODULE_PARM_DESC(debug, "Debug enabled or not");

static struct dentry *dir_ino, *config_ino;

static ssize_t read_server_config(struct file *filp, char __user *buf,
                                  size_t count, loff_t *ppos)
{
        char tmp[256];
        ssize_t len;
        len = scnprintf(tmp, sizeof(tmp), "%s:%d\n", "192.168.0.1", 80);
        return simple_read_from_buffer(buf, count, ppos, tmp, len);
}

static int ioctl_server_config(struct inode *inode, struct file *filp,
                               unsigned int cmd, unsigned long arg)
{
        printk(KERN_INFO "cmd is %d, arg is %s", cmd, (const char *)arg);
        return 0;
}

static long ioctl2_server_config(struct file *filp, unsigned int cmd,
                                 unsigned long arg)
{
        printk(KERN_INFO "cmd is %d, arg is %s", cmd, (const char *)arg);
        return 0;
}

static struct file_operations rootconn_file_ops = {
        .read  = read_server_config,
        .ioctl = ioctl_server_config,
        .unlocked_ioctl = ioctl2_server_config,
        .compat_ioctl   = ioctl2_server_config,
};

static int __init rootplug_init (void)
{
        int rc = 0;
        
        dir_ino = securityfs_create_dir("rootconn", NULL);
        config_ino = securityfs_create_file("server", S_IRUGO, dir_ino, NULL,
                                            &rootconn_file_ops);
        if (IS_ERR(config_ino)) { 
                rc = PTR_ERR(config_ino); 
                securityfs_remove(dir_ino); 
                return PTR_ERR(config_ino); 
        }
        
	printk (KERN_INFO "oreore module registerd\n");
	return 0;
}

static void __exit rootplug_exit (void)
{
        securityfs_remove(config_ino);
        securityfs_remove(dir_ino);
	printk (KERN_INFO "oreore module removed\n");
}

security_initcall (rootplug_init);
module_exit (rootplug_exit);
MODULE_DESCRIPTION("Root Plug sample LSM module, written for Linux Journal article");
MODULE_LICENSE("GPL");