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.
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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
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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_sem
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 down(&dev->struct_sem);
69 for (pt = dev->magiclist[hash].head; pt; pt = pt->next) {
70 if (pt->magic == magic) {
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_sem lock.
90 static int drm_add_magic(drm_device_t * dev, drm_file_t * priv, drm_magic_t magic)
93 drm_magic_entry_t *entry;
95 DRM_DEBUG("%d\n", magic);
97 hash = drm_hash_magic(magic);
98 entry = drm_alloc(sizeof(*entry), DRM_MEM_MAGIC);
101 memset(entry, 0, sizeof(*entry));
102 entry->magic = magic;
106 down(&dev->struct_sem);
107 if (dev->magiclist[hash].tail) {
108 dev->magiclist[hash].tail->next = entry;
109 dev->magiclist[hash].tail = entry;
111 dev->magiclist[hash].head = entry;
112 dev->magiclist[hash].tail = entry;
114 up(&dev->struct_sem);
120 * Remove a magic number.
122 * \param dev DRM device.
123 * \param magic magic number.
125 * Searches and unlinks the entry in drm_device::magiclist with the magic
126 * number hash key, while holding the drm_device::struct_sem lock.
128 static int drm_remove_magic(drm_device_t * dev, drm_magic_t magic)
130 drm_magic_entry_t *prev = NULL;
131 drm_magic_entry_t *pt;
134 DRM_DEBUG("%d\n", magic);
135 hash = drm_hash_magic(magic);
137 down(&dev->struct_sem);
138 for (pt = dev->magiclist[hash].head; pt; prev = pt, pt = pt->next) {
139 if (pt->magic == magic) {
140 if (dev->magiclist[hash].head == pt) {
141 dev->magiclist[hash].head = pt->next;
143 if (dev->magiclist[hash].tail == pt) {
144 dev->magiclist[hash].tail = prev;
147 prev->next = pt->next;
149 up(&dev->struct_sem);
153 up(&dev->struct_sem);
155 drm_free(pt, sizeof(*pt), DRM_MEM_MAGIC);
161 * Get a unique magic number (ioctl).
163 * \param inode device inode.
164 * \param filp file pointer.
165 * \param cmd command.
166 * \param arg pointer to a resulting drm_auth structure.
167 * \return zero on success, or a negative number on failure.
169 * If there is a magic number in drm_file::magic then use it, otherwise
170 * searches an unique non-zero magic number and add it associating it with \p
173 int drm_getmagic(struct inode *inode, struct file *filp,
174 unsigned int cmd, unsigned long arg)
176 static drm_magic_t sequence = 0;
177 static spinlock_t lock = SPIN_LOCK_UNLOCKED;
178 drm_file_t *priv = filp->private_data;
179 drm_device_t *dev = priv->head->dev;
182 /* Find unique magic */
184 auth.magic = priv->magic;
189 ++sequence; /* reserve 0 */
190 auth.magic = sequence++;
192 } while (drm_find_file(dev, auth.magic));
193 priv->magic = auth.magic;
194 drm_add_magic(dev, priv, auth.magic);
197 DRM_DEBUG("%u\n", auth.magic);
198 if (copy_to_user((drm_auth_t __user *) arg, &auth, sizeof(auth)))
204 * Authenticate with a magic.
206 * \param inode device inode.
207 * \param filp file pointer.
208 * \param cmd command.
209 * \param arg pointer to a drm_auth structure.
210 * \return zero if authentication successed, or a negative number otherwise.
212 * Checks if \p filp is associated with the magic number passed in \arg.
214 int drm_authmagic(struct inode *inode, struct file *filp,
215 unsigned int cmd, unsigned long arg)
217 drm_file_t *priv = filp->private_data;
218 drm_device_t *dev = priv->head->dev;
222 if (copy_from_user(&auth, (drm_auth_t __user *) arg, sizeof(auth)))
224 DRM_DEBUG("%u\n", auth.magic);
225 if ((file = drm_find_file(dev, auth.magic))) {
226 file->authenticated = 1;
227 drm_remove_magic(dev, auth.magic);