linux/drivers/gpu/drm/drm_auth.c

/*
 * Created: Tue Feb  2 08:37:54 1999 by faith@valinux.com
 *
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Author Rickard E. (Rik) Faith <faith@valinux.com>
 * Author Gareth Hughes <gareth@valinux.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */

#include <drm/drmP.h>
#include "drm_internal.h"

/**
 * drm_getmagic - Get unique magic of a client
 * @dev: DRM device to operate on
 * @data: ioctl data containing the drm_auth object
 * @file_priv: DRM file that performs the operation
 *
 * This looks up the unique magic of the passed client and returns it. If the
 * client did not have a magic assigned, yet, a new one is registered. The magic
 * is stored in the passed drm_auth object.
 *
 * Returns: 0 on success, negative error code on failure.
 */
int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	struct drm_auth *auth = data;
	int ret = 0;

	mutex_lock(&dev->struct_mutex);
	if (!file_priv->magic) {
		ret = idr_alloc(&file_priv->master->magic_map, file_priv,
				1, 0, GFP_KERNEL);
		if (ret >= 0)
			file_priv->magic = ret;
	}
	auth->magic = file_priv->magic;
	mutex_unlock(&dev->struct_mutex);

	DRM_DEBUG("%u\n", auth->magic);

	return ret < 0 ? ret : 0;
}

/**
 * drm_authmagic - Authenticate client with a magic
 * @dev: DRM device to operate on
 * @data: ioctl data containing the drm_auth object
 * @file_priv: DRM file that performs the operation
 *
 * This looks up a DRM client by the passed magic and authenticates it.
 *
 * Returns: 0 on success, negative error code on failure.
 */
int drm_authmagic(struct drm_device *dev, void *data,
		  struct drm_file *file_priv)
{
	struct drm_auth *auth = data;
	struct drm_file *file;

	DRM_DEBUG("%u\n", auth->magic);

	mutex_lock(&dev->struct_mutex);
	file = idr_find(&file_priv->master->magic_map, auth->magic);
	if (file) {
		file->authenticated = 1;
		idr_replace(&file_priv->master->magic_map, NULL, auth->magic);
	}
	mutex_unlock(&dev->struct_mutex);

	return file ? 0 : -EINVAL;
}