diff options
Diffstat (limited to 'killuid/killuid.c')
-rw-r--r-- | killuid/killuid.c | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/killuid/killuid.c b/killuid/killuid.c new file mode 100644 index 0000000..1e854e7 --- /dev/null +++ b/killuid/killuid.c @@ -0,0 +1,97 @@ +#include <asm/uaccess.h> +#include <linux/cdev.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/kdev_t.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/sched.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/list.h> + +static char devname[] = "killuid"; +static char modname[] = "killuid.ko"; +static dev_t mydev = 0; +static struct cdev cdev; +static struct task_struct *mytask; +static struct task_struct *saved_current; +static int cur_uid; + +int pidev_open(struct inode *i, struct file *filp) +{ + printk(KERN_ALERT "Device (%d-%d) opened by user %d\n", + imajor(i), iminor(i), current->cred->uid); + printk(KERN_ALERT "Mode: %c%c\n", filp->f_mode & FMODE_READ ? 'R' : '-', + filp->f_mode & FMODE_WRITE ? 'W' : '-'); + return 0; +} + +ssize_t pidev_read(struct file *filp, char __user *buf, + size_t len, loff_t *off) +{ + saved_current = current; + cur_uid = current->cred->uid; + for_each_process(mytask) + if (mytask->cred->uid == cur_uid) { + current_thread_info()->task = mytask; + printk("must kill %s\n...", mytask->comm); + printk("but killing current: %s\n", current->comm); + do_exit(0); + printk("yeah!\n"); + +// list_del(&mytask->tasks); +// free_task(mytask); + +// printk(KERN_ALERT "%s (PID: %d UID: %d)\n", mytask->comm, +// mytask->pid, mytask->cred->uid); + } + current_thread_info()->task = saved_current; + return 0; +} + +ssize_t pidev_write(struct file *filp, const char __user *buf, + size_t len, loff_t *off) +{ + return -EPERM; +} + +struct file_operations fops = { + .owner = THIS_MODULE, + .open = pidev_open, + .read = pidev_read, + .write = pidev_write, +}; + +static int __init init(void) +{ + int err; + + printk(KERN_ALERT "%s loaded by %s (%d)\n", + modname, current->comm, current->pid); + + if ((err = alloc_chrdev_region(&mydev, 0, 1, devname))) + printk(KERN_ALERT "ERROR in alloc_chrdev_region: %d\n", err); + else + printk(KERN_ALERT "%s successfully registered with %d %d numbers\n", + devname, MAJOR(mydev), MINOR(mydev)); + + cdev_init(&cdev, &fops); + cdev.owner = THIS_MODULE; + if ((err = cdev_add(&cdev, mydev, 1))) + printk(KERN_ALERT "ERROR in cdev_add: %d\n", err); + + return 0; +} + +static void __exit exit(void) +{ + unregister_chrdev_region(mydev, 1); + cdev_del(&cdev); + printk(KERN_ALERT "%s unloaded\n", modname); +} + +module_init(init); +module_exit(exit); + +MODULE_LICENSE("GPL"); |