static long usblp_ioctl()

in class/usblp.c [519:717]

• 170 lines of code
• 38 McCabe index (conditional complexity)

static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
	struct usblp *usblp = file->private_data;
	int length, err, i;
	unsigned char newChannel;
	int status;
	int twoints[2];
	int retval = 0;

	mutex_lock(&usblp->mut);
	if (!usblp->present) {
		retval = -ENODEV;
		goto done;
	}

	dev_dbg(&usblp->intf->dev,
		"usblp_ioctl: cmd=0x%x (%c nr=%d len=%d dir=%d)\n", cmd,
		_IOC_TYPE(cmd), _IOC_NR(cmd), _IOC_SIZE(cmd), _IOC_DIR(cmd));

	if (_IOC_TYPE(cmd) == 'P')	/* new-style ioctl number */

		switch (_IOC_NR(cmd)) {

		case IOCNR_GET_DEVICE_ID: /* get the DEVICE_ID string */
			if (_IOC_DIR(cmd) != _IOC_READ) {
				retval = -EINVAL;
				goto done;
			}

			length = usblp_cache_device_id_string(usblp);
			if (length < 0) {
				retval = length;
				goto done;
			}
			if (length > _IOC_SIZE(cmd))
				length = _IOC_SIZE(cmd); /* truncate */

			if (copy_to_user((void __user *) arg,
					usblp->device_id_string,
					(unsigned long) length)) {
				retval = -EFAULT;
				goto done;
			}

			break;

		case IOCNR_GET_PROTOCOLS:
			if (_IOC_DIR(cmd) != _IOC_READ ||
			    _IOC_SIZE(cmd) < sizeof(twoints)) {
				retval = -EINVAL;
				goto done;
			}

			twoints[0] = usblp->current_protocol;
			twoints[1] = 0;
			for (i = USBLP_FIRST_PROTOCOL;
			     i <= USBLP_LAST_PROTOCOL; i++) {
				if (usblp->protocol[i].alt_setting >= 0)
					twoints[1] |= (1<<i);
			}

			if (copy_to_user((void __user *)arg,
					(unsigned char *)twoints,
					sizeof(twoints))) {
				retval = -EFAULT;
				goto done;
			}

			break;

		case IOCNR_SET_PROTOCOL:
			if (_IOC_DIR(cmd) != _IOC_WRITE) {
				retval = -EINVAL;
				goto done;
			}

#ifdef DEBUG
			if (arg == -10) {
				usblp_dump(usblp);
				break;
			}
#endif

			usblp_unlink_urbs(usblp);
			retval = usblp_set_protocol(usblp, arg);
			if (retval < 0) {
				usblp_set_protocol(usblp,
					usblp->current_protocol);
			}
			break;

		case IOCNR_HP_SET_CHANNEL:
			if (_IOC_DIR(cmd) != _IOC_WRITE ||
			    le16_to_cpu(usblp->dev->descriptor.idVendor) != 0x03F0 ||
			    usblp->quirks & USBLP_QUIRK_BIDIR) {
				retval = -EINVAL;
				goto done;
			}

			err = usblp_hp_channel_change_request(usblp,
				arg, &newChannel);
			if (err < 0) {
				dev_err(&usblp->dev->dev,
					"usblp%d: error = %d setting "
					"HP channel\n",
					usblp->minor, err);
				retval = -EIO;
				goto done;
			}

			dev_dbg(&usblp->intf->dev,
				"usblp%d requested/got HP channel %ld/%d\n",
				usblp->minor, arg, newChannel);
			break;

		case IOCNR_GET_BUS_ADDRESS:
			if (_IOC_DIR(cmd) != _IOC_READ ||
			    _IOC_SIZE(cmd) < sizeof(twoints)) {
				retval = -EINVAL;
				goto done;
			}

			twoints[0] = usblp->dev->bus->busnum;
			twoints[1] = usblp->dev->devnum;
			if (copy_to_user((void __user *)arg,
					(unsigned char *)twoints,
					sizeof(twoints))) {
				retval = -EFAULT;
				goto done;
			}

			dev_dbg(&usblp->intf->dev,
				"usblp%d is bus=%d, device=%d\n",
				usblp->minor, twoints[0], twoints[1]);
			break;

		case IOCNR_GET_VID_PID:
			if (_IOC_DIR(cmd) != _IOC_READ ||
			    _IOC_SIZE(cmd) < sizeof(twoints)) {
				retval = -EINVAL;
				goto done;
			}

			twoints[0] = le16_to_cpu(usblp->dev->descriptor.idVendor);
			twoints[1] = le16_to_cpu(usblp->dev->descriptor.idProduct);
			if (copy_to_user((void __user *)arg,
					(unsigned char *)twoints,
					sizeof(twoints))) {
				retval = -EFAULT;
				goto done;
			}

			dev_dbg(&usblp->intf->dev,
				"usblp%d is VID=0x%4.4X, PID=0x%4.4X\n",
				usblp->minor, twoints[0], twoints[1]);
			break;

		case IOCNR_SOFT_RESET:
			if (_IOC_DIR(cmd) != _IOC_NONE) {
				retval = -EINVAL;
				goto done;
			}
			retval = usblp_reset(usblp);
			break;
		default:
			retval = -ENOTTY;
		}
	else	/* old-style ioctl value */
		switch (cmd) {

		case LPGETSTATUS:
			retval = usblp_read_status(usblp, usblp->statusbuf);
			if (retval) {
				printk_ratelimited(KERN_ERR "usblp%d:"
					    "failed reading printer status (%d)\n",
					    usblp->minor, retval);
				retval = -EIO;
				goto done;
			}
			status = *usblp->statusbuf;
			if (copy_to_user((void __user *)arg, &status, sizeof(int)))
				retval = -EFAULT;
			break;

		case LPABORT:
			if (arg)
				usblp->flags |= LP_ABORT;
			else
				usblp->flags &= ~LP_ABORT;
			break;

		default:
			retval = -ENOTTY;
		}

done:
	mutex_unlock(&usblp->mut);
	return retval;
}