#include #include #include #include #include #include #include #include #include #include static char devname[] = "pidevice"; static char modname[] = "pidevice.ko"; static dev_t mydev = 0; static struct cdev cdev; static struct task_struct *mytask; static struct task_struct *parent; static int count = 1; int pidev_open(struct inode *i, struct file *filp) { count = 1; printk(KERN_ALERT "Device (%d-%d) opened\n", imajor(i), iminor(i)); 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) { if (count--) { copy_to_user(buf, modname, 12); return 12; } else { return 0; } } ssize_t pidev_write(struct file *filp, const char __user *buf, size_t len, loff_t *off) { char localbuf[40]; copy_from_user(localbuf, buf, 40); localbuf[len] = '\0'; printk(KERN_ALERT "Recibido: %s", localbuf); return -EPERM; } struct file_operations fops = { .owner = THIS_MODULE, .open = pidev_open, .read = pidev_read, .write = pidev_write, }; static void show_processes(void) { mytask = current; parent = mytask->parent; while (mytask->pid != parent->pid) { printk(KERN_ALERT "current: %s (%d) - parent: %s (%d)\n", mytask->comm, mytask->pid, parent->comm, parent->pid); mytask = mytask->parent; parent = mytask->parent; } } 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");