3 * IOCTLs for authentication
5 * \author Rickard E. (Rik) Faith <faith@valinux.com>
6 * \author Gareth Hughes <gareth@valinux.com>
10 * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com
12 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
14 * All Rights Reserved.
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:
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
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.
39 * Generate a hash key from a magic.
44 * The key is the modulus of the hash table size, #DRM_HASH_SIZE, which must be
47 static int drm_hash_magic(drm_magic_t magic
)
49 return magic
& (DRM_HASH_SIZE
- 1);
53 * Find the file with the given magic number.
55 * \param dev DRM device.
56 * \param magic magic number.
58 * Searches in drm_device::magiclist within all files with the same hash key
59 * the one with matching magic number, while holding the drm_device::struct_mutex
62 static drm_file_t
*drm_find_file(drm_device_t
* dev
, drm_magic_t magic
)
64 drm_file_t
*retval
= NULL
;
65 drm_magic_entry_t
*pt
;
66 int hash
= drm_hash_magic(magic
);
68 mutex_lock(&dev
->struct_mutex
);
69 for (pt
= dev
->magiclist
[hash
].head
; pt
; pt
= pt
->next
) {
70 if (pt
->magic
== magic
) {
75 mutex_unlock(&dev
->struct_mutex
);
80 * Adds a magic number.
82 * \param dev DRM device.
83 * \param priv file private data.
84 * \param magic magic number.
86 * Creates a drm_magic_entry structure and appends to the linked list
87 * associated the magic number hash key in drm_device::magiclist, while holding
88 * the drm_device::struct_mutex lock.
90 static int drm_add_magic(drm_device_t
* dev
, drm_file_t
* priv
,
94 drm_magic_entry_t
*entry
;
96 DRM_DEBUG("%d\n", magic
);
98 hash
= drm_hash_magic(magic
);
99 entry
= drm_alloc(sizeof(*entry
), DRM_MEM_MAGIC
);
102 memset(entry
, 0, sizeof(*entry
));
103 entry
->magic
= magic
;
107 mutex_lock(&dev
->struct_mutex
);
108 if (dev
->magiclist
[hash
].tail
) {
109 dev
->magiclist
[hash
].tail
->next
= entry
;
110 dev
->magiclist
[hash
].tail
= entry
;
112 dev
->magiclist
[hash
].head
= entry
;
113 dev
->magiclist
[hash
].tail
= entry
;
115 mutex_unlock(&dev
->struct_mutex
);
121 * Remove a magic number.
123 * \param dev DRM device.
124 * \param magic magic number.
126 * Searches and unlinks the entry in drm_device::magiclist with the magic
127 * number hash key, while holding the drm_device::struct_mutex lock.
129 static int drm_remove_magic(drm_device_t
* dev
, drm_magic_t magic
)
131 drm_magic_entry_t
*prev
= NULL
;
132 drm_magic_entry_t
*pt
;
135 DRM_DEBUG("%d\n", magic
);
136 hash
= drm_hash_magic(magic
);
138 mutex_lock(&dev
->struct_mutex
);
139 for (pt
= dev
->magiclist
[hash
].head
; pt
; prev
= pt
, pt
= pt
->next
) {
140 if (pt
->magic
== magic
) {
141 if (dev
->magiclist
[hash
].head
== pt
) {
142 dev
->magiclist
[hash
].head
= pt
->next
;
144 if (dev
->magiclist
[hash
].tail
== pt
) {
145 dev
->magiclist
[hash
].tail
= prev
;
148 prev
->next
= pt
->next
;
150 mutex_unlock(&dev
->struct_mutex
);
154 mutex_unlock(&dev
->struct_mutex
);
156 drm_free(pt
, sizeof(*pt
), DRM_MEM_MAGIC
);
162 * Get a unique magic number (ioctl).
164 * \param inode device inode.
165 * \param filp file pointer.
166 * \param cmd command.
167 * \param arg pointer to a resulting drm_auth structure.
168 * \return zero on success, or a negative number on failure.
170 * If there is a magic number in drm_file::magic then use it, otherwise
171 * searches an unique non-zero magic number and add it associating it with \p
174 int drm_getmagic(struct inode
*inode
, struct file
*filp
,
175 unsigned int cmd
, unsigned long arg
)
177 static drm_magic_t sequence
= 0;
178 static DEFINE_SPINLOCK(lock
);
179 drm_file_t
*priv
= filp
->private_data
;
180 drm_device_t
*dev
= priv
->head
->dev
;
183 /* Find unique magic */
185 auth
.magic
= priv
->magic
;
190 ++sequence
; /* reserve 0 */
191 auth
.magic
= sequence
++;
193 } while (drm_find_file(dev
, auth
.magic
));
194 priv
->magic
= auth
.magic
;
195 drm_add_magic(dev
, priv
, auth
.magic
);
198 DRM_DEBUG("%u\n", auth
.magic
);
199 if (copy_to_user((drm_auth_t __user
*) arg
, &auth
, sizeof(auth
)))
205 * Authenticate with a magic.
207 * \param inode device inode.
208 * \param filp file pointer.
209 * \param cmd command.
210 * \param arg pointer to a drm_auth structure.
211 * \return zero if authentication successed, or a negative number otherwise.
213 * Checks if \p filp is associated with the magic number passed in \arg.
215 int drm_authmagic(struct inode
*inode
, struct file
*filp
,
216 unsigned int cmd
, unsigned long arg
)
218 drm_file_t
*priv
= filp
->private_data
;
219 drm_device_t
*dev
= priv
->head
->dev
;
223 if (copy_from_user(&auth
, (drm_auth_t __user
*) arg
, sizeof(auth
)))
225 DRM_DEBUG("%u\n", auth
.magic
);
226 if ((file
= drm_find_file(dev
, auth
.magic
))) {
227 file
->authenticated
= 1;
228 drm_remove_magic(dev
, auth
.magic
);