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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 */
46int 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 */
76int 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}
1/**
2 * \file drm_auth.c
3 * IOCTLs for authentication
4 *
5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com>
7 */
8
9/*
10 * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com
11 *
12 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
15 *
16 * Permission is hereby granted, free of charge, to any person obtaining a
17 * copy of this software and associated documentation files (the "Software"),
18 * to deal in the Software without restriction, including without limitation
19 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
20 * and/or sell copies of the Software, and to permit persons to whom the
21 * Software is furnished to do so, subject to the following conditions:
22 *
23 * The above copyright notice and this permission notice (including the next
24 * paragraph) shall be included in all copies or substantial portions of the
25 * Software.
26 *
27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
33 * OTHER DEALINGS IN THE SOFTWARE.
34 */
35
36#include "drmP.h"
37
38/**
39 * Find the file with the given magic number.
40 *
41 * \param dev DRM device.
42 * \param magic magic number.
43 *
44 * Searches in drm_device::magiclist within all files with the same hash key
45 * the one with matching magic number, while holding the drm_device::struct_mutex
46 * lock.
47 */
48static struct drm_file *drm_find_file(struct drm_master *master, drm_magic_t magic)
49{
50 struct drm_file *retval = NULL;
51 struct drm_magic_entry *pt;
52 struct drm_hash_item *hash;
53 struct drm_device *dev = master->minor->dev;
54
55 mutex_lock(&dev->struct_mutex);
56 if (!drm_ht_find_item(&master->magiclist, (unsigned long)magic, &hash)) {
57 pt = drm_hash_entry(hash, struct drm_magic_entry, hash_item);
58 retval = pt->priv;
59 }
60 mutex_unlock(&dev->struct_mutex);
61 return retval;
62}
63
64/**
65 * Adds a magic number.
66 *
67 * \param dev DRM device.
68 * \param priv file private data.
69 * \param magic magic number.
70 *
71 * Creates a drm_magic_entry structure and appends to the linked list
72 * associated the magic number hash key in drm_device::magiclist, while holding
73 * the drm_device::struct_mutex lock.
74 */
75static int drm_add_magic(struct drm_master *master, struct drm_file *priv,
76 drm_magic_t magic)
77{
78 struct drm_magic_entry *entry;
79 struct drm_device *dev = master->minor->dev;
80 DRM_DEBUG("%d\n", magic);
81
82 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
83 if (!entry)
84 return -ENOMEM;
85 entry->priv = priv;
86 entry->hash_item.key = (unsigned long)magic;
87 mutex_lock(&dev->struct_mutex);
88 drm_ht_insert_item(&master->magiclist, &entry->hash_item);
89 list_add_tail(&entry->head, &master->magicfree);
90 mutex_unlock(&dev->struct_mutex);
91
92 return 0;
93}
94
95/**
96 * Remove a magic number.
97 *
98 * \param dev DRM device.
99 * \param magic magic number.
100 *
101 * Searches and unlinks the entry in drm_device::magiclist with the magic
102 * number hash key, while holding the drm_device::struct_mutex lock.
103 */
104static int drm_remove_magic(struct drm_master *master, drm_magic_t magic)
105{
106 struct drm_magic_entry *pt;
107 struct drm_hash_item *hash;
108 struct drm_device *dev = master->minor->dev;
109
110 DRM_DEBUG("%d\n", magic);
111
112 mutex_lock(&dev->struct_mutex);
113 if (drm_ht_find_item(&master->magiclist, (unsigned long)magic, &hash)) {
114 mutex_unlock(&dev->struct_mutex);
115 return -EINVAL;
116 }
117 pt = drm_hash_entry(hash, struct drm_magic_entry, hash_item);
118 drm_ht_remove_item(&master->magiclist, hash);
119 list_del(&pt->head);
120 mutex_unlock(&dev->struct_mutex);
121
122 kfree(pt);
123
124 return 0;
125}
126
127/**
128 * Get a unique magic number (ioctl).
129 *
130 * \param inode device inode.
131 * \param file_priv DRM file private.
132 * \param cmd command.
133 * \param arg pointer to a resulting drm_auth structure.
134 * \return zero on success, or a negative number on failure.
135 *
136 * If there is a magic number in drm_file::magic then use it, otherwise
137 * searches an unique non-zero magic number and add it associating it with \p
138 * file_priv.
139 */
140int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
141{
142 static drm_magic_t sequence = 0;
143 static DEFINE_SPINLOCK(lock);
144 struct drm_auth *auth = data;
145
146 /* Find unique magic */
147 if (file_priv->magic) {
148 auth->magic = file_priv->magic;
149 } else {
150 do {
151 spin_lock(&lock);
152 if (!sequence)
153 ++sequence; /* reserve 0 */
154 auth->magic = sequence++;
155 spin_unlock(&lock);
156 } while (drm_find_file(file_priv->master, auth->magic));
157 file_priv->magic = auth->magic;
158 drm_add_magic(file_priv->master, file_priv, auth->magic);
159 }
160
161 DRM_DEBUG("%u\n", auth->magic);
162
163 return 0;
164}
165
166/**
167 * Authenticate with a magic.
168 *
169 * \param inode device inode.
170 * \param file_priv DRM file private.
171 * \param cmd command.
172 * \param arg pointer to a drm_auth structure.
173 * \return zero if authentication successed, or a negative number otherwise.
174 *
175 * Checks if \p file_priv is associated with the magic number passed in \arg.
176 */
177int drm_authmagic(struct drm_device *dev, void *data,
178 struct drm_file *file_priv)
179{
180 struct drm_auth *auth = data;
181 struct drm_file *file;
182
183 DRM_DEBUG("%u\n", auth->magic);
184 if ((file = drm_find_file(file_priv->master, auth->magic))) {
185 file->authenticated = 1;
186 drm_remove_magic(file_priv->master, auth->magic);
187 return 0;
188 }
189 return -EINVAL;
190}