uinput.c

来自「linux 内核源代码」· C语言 代码 · 共 661 行 · 第 1/2 页

	memcpy(dev->absflat, user_dev->absflat, size);

	/* check if absmin/absmax/absfuzz/absflat are filled as
	 * told in Documentation/input/input-programming.txt */
	if (test_bit(EV_ABS, dev->evbit)) {
		retval = uinput_validate_absbits(dev);
		if (retval < 0)
			goto exit;
	}

	udev->state = UIST_SETUP_COMPLETE;
	retval = count;

 exit:
	kfree(user_dev);
	return retval;
}

static inline ssize_t uinput_inject_event(struct uinput_device *udev, const char __user *buffer, size_t count)
{
	struct input_event ev;

	if (count != sizeof(struct input_event))
		return -EINVAL;

	if (copy_from_user(&ev, buffer, sizeof(struct input_event)))
		return -EFAULT;

	input_event(udev->dev, ev.type, ev.code, ev.value);

	return sizeof(struct input_event);
}

static ssize_t uinput_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
	struct uinput_device *udev = file->private_data;
	int retval;

	retval = mutex_lock_interruptible(&udev->mutex);
	if (retval)
		return retval;

	retval = udev->state == UIST_CREATED ?
			uinput_inject_event(udev, buffer, count) :
			uinput_setup_device(udev, buffer, count);

	mutex_unlock(&udev->mutex);

	return retval;
}

static ssize_t uinput_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
	struct uinput_device *udev = file->private_data;
	int retval = 0;

	if (udev->state != UIST_CREATED)
		return -ENODEV;

	if (udev->head == udev->tail && (file->f_flags & O_NONBLOCK))
		return -EAGAIN;

	retval = wait_event_interruptible(udev->waitq,
			udev->head != udev->tail || udev->state != UIST_CREATED);
	if (retval)
		return retval;

	retval = mutex_lock_interruptible(&udev->mutex);
	if (retval)
		return retval;

	if (udev->state != UIST_CREATED) {
		retval = -ENODEV;
		goto out;
	}

	while (udev->head != udev->tail && retval + sizeof(struct input_event) <= count) {
		if (copy_to_user(buffer + retval, &udev->buff[udev->tail], sizeof(struct input_event))) {
			retval = -EFAULT;
			goto out;
		}
		udev->tail = (udev->tail + 1) % UINPUT_BUFFER_SIZE;
		retval += sizeof(struct input_event);
	}

 out:
	mutex_unlock(&udev->mutex);

	return retval;
}

static unsigned int uinput_poll(struct file *file, poll_table *wait)
{
	struct uinput_device *udev = file->private_data;

	poll_wait(file, &udev->waitq, wait);

	if (udev->head != udev->tail)
		return POLLIN | POLLRDNORM;

	return 0;
}

static int uinput_release(struct inode *inode, struct file *file)
{
	struct uinput_device *udev = file->private_data;

	uinput_destroy_device(udev);
	kfree(udev);

	return 0;
}

#define uinput_set_bit(_arg, _bit, _max)		\
({							\
	int __ret = 0;					\
	if (udev->state == UIST_CREATED)		\
		__ret =  -EINVAL;			\
	else if ((_arg) > (_max))			\
		__ret = -EINVAL;			\
	else set_bit((_arg), udev->dev->_bit);		\
	__ret;						\
})

static long uinput_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	int			retval;
	struct uinput_device	*udev;
	void __user             *p = (void __user *)arg;
	struct uinput_ff_upload ff_up;
	struct uinput_ff_erase  ff_erase;
	struct uinput_request   *req;
	int                     length;
	char			*phys;

	udev = file->private_data;

	retval = mutex_lock_interruptible(&udev->mutex);
	if (retval)
		return retval;

	if (!udev->dev) {
		retval = uinput_allocate_device(udev);
		if (retval)
			goto out;
	}

	switch (cmd) {
		case UI_DEV_CREATE:
			retval = uinput_create_device(udev);
			break;

		case UI_DEV_DESTROY:
			uinput_destroy_device(udev);
			break;

		case UI_SET_EVBIT:
			retval = uinput_set_bit(arg, evbit, EV_MAX);
			break;

		case UI_SET_KEYBIT:
			retval = uinput_set_bit(arg, keybit, KEY_MAX);
			break;

		case UI_SET_RELBIT:
			retval = uinput_set_bit(arg, relbit, REL_MAX);
			break;

		case UI_SET_ABSBIT:
			retval = uinput_set_bit(arg, absbit, ABS_MAX);
			break;

		case UI_SET_MSCBIT:
			retval = uinput_set_bit(arg, mscbit, MSC_MAX);
			break;

		case UI_SET_LEDBIT:
			retval = uinput_set_bit(arg, ledbit, LED_MAX);
			break;

		case UI_SET_SNDBIT:
			retval = uinput_set_bit(arg, sndbit, SND_MAX);
			break;

		case UI_SET_FFBIT:
			retval = uinput_set_bit(arg, ffbit, FF_MAX);
			break;

		case UI_SET_SWBIT:
			retval = uinput_set_bit(arg, swbit, SW_MAX);
			break;

		case UI_SET_PHYS:
			if (udev->state == UIST_CREATED) {
				retval = -EINVAL;
				goto out;
			}
			length = strnlen_user(p, 1024);
			if (length <= 0) {
				retval = -EFAULT;
				break;
			}
			kfree(udev->dev->phys);
			udev->dev->phys = phys = kmalloc(length, GFP_KERNEL);
			if (!phys) {
				retval = -ENOMEM;
				break;
			}
			if (copy_from_user(phys, p, length)) {
				udev->dev->phys = NULL;
				kfree(phys);
				retval = -EFAULT;
				break;
			}
			phys[length - 1] = '\0';
			break;

		case UI_BEGIN_FF_UPLOAD:
			if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
				retval = -EFAULT;
				break;
			}
			req = uinput_request_find(udev, ff_up.request_id);
			if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
				retval = -EINVAL;
				break;
			}
			ff_up.retval = 0;
			memcpy(&ff_up.effect, req->u.upload.effect, sizeof(struct ff_effect));
			if (req->u.upload.old)
				memcpy(&ff_up.old, req->u.upload.old, sizeof(struct ff_effect));
			else
				memset(&ff_up.old, 0, sizeof(struct ff_effect));

			if (copy_to_user(p, &ff_up, sizeof(ff_up))) {
				retval = -EFAULT;
				break;
			}
			break;

		case UI_BEGIN_FF_ERASE:
			if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
				retval = -EFAULT;
				break;
			}
			req = uinput_request_find(udev, ff_erase.request_id);
			if (!(req && req->code == UI_FF_ERASE)) {
				retval = -EINVAL;
				break;
			}
			ff_erase.retval = 0;
			ff_erase.effect_id = req->u.effect_id;
			if (copy_to_user(p, &ff_erase, sizeof(ff_erase))) {
				retval = -EFAULT;
				break;
			}
			break;

		case UI_END_FF_UPLOAD:
			if (copy_from_user(&ff_up, p, sizeof(ff_up))) {
				retval = -EFAULT;
				break;
			}
			req = uinput_request_find(udev, ff_up.request_id);
			if (!(req && req->code == UI_FF_UPLOAD && req->u.upload.effect)) {
				retval = -EINVAL;
				break;
			}
			req->retval = ff_up.retval;
			uinput_request_done(udev, req);
			break;

		case UI_END_FF_ERASE:
			if (copy_from_user(&ff_erase, p, sizeof(ff_erase))) {
				retval = -EFAULT;
				break;
			}
			req = uinput_request_find(udev, ff_erase.request_id);
			if (!(req && req->code == UI_FF_ERASE)) {
				retval = -EINVAL;
				break;
			}
			req->retval = ff_erase.retval;
			uinput_request_done(udev, req);
			break;

		default:
			retval = -EINVAL;
	}

 out:
	mutex_unlock(&udev->mutex);
	return retval;
}

static const struct file_operations uinput_fops = {
	.owner		= THIS_MODULE,
	.open		= uinput_open,
	.release	= uinput_release,
	.read		= uinput_read,
	.write		= uinput_write,
	.poll		= uinput_poll,
	.unlocked_ioctl	= uinput_ioctl,
};

static struct miscdevice uinput_misc = {
	.fops		= &uinput_fops,
	.minor		= UINPUT_MINOR,
	.name		= UINPUT_NAME,
};

static int __init uinput_init(void)
{
	return misc_register(&uinput_misc);
}

static void __exit uinput_exit(void)
{
	misc_deregister(&uinput_misc);
}

MODULE_AUTHOR("Aristeu Sergio Rozanski Filho");
MODULE_DESCRIPTION("User level driver support for input subsystem");
MODULE_LICENSE("GPL");
MODULE_VERSION("0.3");

module_init(uinput_init);
module_exit(uinput_exit);