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 <drm/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 | */ |
48 | static 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 | */ |
75 | static 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 | */ |
104 | 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 | * This ioctl needs protection by the drm_global_mutex, which protects |
140 | * struct drm_file::magic and struct drm_magic_entry::priv. |
141 | */ |
142 | int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) |
143 | { |
144 | static atomic_t sequence = ATOMIC_INIT(0); |
145 | struct drm_auth *auth = data; |
146 | |
147 | /* Find unique magic */ |
148 | if (file_priv->magic) { |
149 | auth->magic = file_priv->magic; |
150 | } else { |
151 | do { |
152 | auth->magic = atomic_inc_return(&sequence); |
153 | } while (drm_find_file(file_priv->master, auth->magic)); |
154 | file_priv->magic = auth->magic; |
155 | drm_add_magic(file_priv->master, file_priv, auth->magic); |
156 | } |
157 | |
158 | DRM_DEBUG("%u\n" , auth->magic); |
159 | |
160 | return 0; |
161 | } |
162 | |
163 | /** |
164 | * Authenticate with a magic. |
165 | * |
166 | * \param inode device inode. |
167 | * \param file_priv DRM file private. |
168 | * \param cmd command. |
169 | * \param arg pointer to a drm_auth structure. |
170 | * \return zero if authentication successed, or a negative number otherwise. |
171 | * |
172 | * Checks if \p file_priv is associated with the magic number passed in \arg. |
173 | * This ioctl needs protection by the drm_global_mutex, which protects |
174 | * struct drm_file::magic and struct drm_magic_entry::priv. |
175 | */ |
176 | int drm_authmagic(struct drm_device *dev, void *data, |
177 | struct drm_file *file_priv) |
178 | { |
179 | struct drm_auth *auth = data; |
180 | struct drm_file *file; |
181 | |
182 | DRM_DEBUG("%u\n" , auth->magic); |
183 | if ((file = drm_find_file(file_priv->master, auth->magic))) { |
184 | file->authenticated = 1; |
185 | drm_remove_magic(file_priv->master, auth->magic); |
186 | return 0; |
187 | } |
188 | return -EINVAL; |
189 | } |
190 | |