xref: /openbmc/linux/drivers/gpu/drm/drm_auth.c (revision ca55b2fe)
1 /*
2  * Created: Tue Feb  2 08:37:54 1999 by faith@valinux.com
3  *
4  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6  * All Rights Reserved.
7  *
8  * Author Rickard E. (Rik) Faith <faith@valinux.com>
9  * Author Gareth Hughes <gareth@valinux.com>
10  *
11  * Permission is hereby granted, free of charge, to any person obtaining a
12  * copy of this software and associated documentation files (the "Software"),
13  * to deal in the Software without restriction, including without limitation
14  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
15  * and/or sell copies of the Software, and to permit persons to whom the
16  * Software is furnished to do so, subject to the following conditions:
17  *
18  * The above copyright notice and this permission notice (including the next
19  * paragraph) shall be included in all copies or substantial portions of the
20  * Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
25  * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
26  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
27  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
28  * OTHER DEALINGS IN THE SOFTWARE.
29  */
30 
31 #include <drm/drmP.h>
32 #include "drm_internal.h"
33 
34 /**
35  * drm_getmagic - Get unique magic of a client
36  * @dev: DRM device to operate on
37  * @data: ioctl data containing the drm_auth object
38  * @file_priv: DRM file that performs the operation
39  *
40  * This looks up the unique magic of the passed client and returns it. If the
41  * client did not have a magic assigned, yet, a new one is registered. The magic
42  * is stored in the passed drm_auth object.
43  *
44  * Returns: 0 on success, negative error code on failure.
45  */
46 int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
47 {
48 	struct drm_auth *auth = data;
49 	int ret = 0;
50 
51 	mutex_lock(&dev->struct_mutex);
52 	if (!file_priv->magic) {
53 		ret = idr_alloc(&file_priv->master->magic_map, file_priv,
54 				1, 0, GFP_KERNEL);
55 		if (ret >= 0)
56 			file_priv->magic = ret;
57 	}
58 	auth->magic = file_priv->magic;
59 	mutex_unlock(&dev->struct_mutex);
60 
61 	DRM_DEBUG("%u\n", auth->magic);
62 
63 	return ret < 0 ? ret : 0;
64 }
65 
66 /**
67  * drm_authmagic - Authenticate client with a magic
68  * @dev: DRM device to operate on
69  * @data: ioctl data containing the drm_auth object
70  * @file_priv: DRM file that performs the operation
71  *
72  * This looks up a DRM client by the passed magic and authenticates it.
73  *
74  * Returns: 0 on success, negative error code on failure.
75  */
76 int drm_authmagic(struct drm_device *dev, void *data,
77 		  struct drm_file *file_priv)
78 {
79 	struct drm_auth *auth = data;
80 	struct drm_file *file;
81 
82 	DRM_DEBUG("%u\n", auth->magic);
83 
84 	mutex_lock(&dev->struct_mutex);
85 	file = idr_find(&file_priv->master->magic_map, auth->magic);
86 	if (file) {
87 		file->authenticated = 1;
88 		idr_replace(&file_priv->master->magic_map, NULL, auth->magic);
89 	}
90 	mutex_unlock(&dev->struct_mutex);
91 
92 	return file ? 0 : -EINVAL;
93 }
94