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.
36 #define __NO_VERSION__
40 * Generate a hash key from a magic.
45 * The key is the modulus of the hash table size, #DRM_HASH_SIZE, which must be
48 static int DRM(hash_magic)(drm_magic_t magic)
50 return magic & (DRM_HASH_SIZE-1);
54 * Find the file with the given magic number.
56 * \param dev DRM device.
57 * \param magic magic number.
59 * Searches in drm_device::magiclist within all files with the same hash key
60 * the one with matching magic number, while holding the drm_device::struct_sem
63 static drm_file_t *DRM(find_file)(drm_device_t *dev, drm_magic_t magic)
65 drm_file_t *retval = NULL;
66 drm_magic_entry_t *pt;
67 int hash = DRM(hash_magic)(magic);
69 down(&dev->struct_sem);
70 for (pt = dev->magiclist[hash].head; pt; pt = pt->next) {
71 if (pt->magic == magic) {
81 * Adds a magic number.
83 * \param dev DRM device.
84 * \param priv file private data.
85 * \param magic magic number.
87 * Creates a drm_magic_entry structure and appends to the linked list
88 * associated the magic number hash key in drm_device::magiclist, while holding
89 * the drm_device::struct_sem lock.
91 int DRM(add_magic)(drm_device_t *dev, drm_file_t *priv, drm_magic_t magic)
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);
100 if (!entry) return -ENOMEM;
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 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;
135 DRM_DEBUG("%d\n", magic);
136 hash = DRM(hash_magic)(magic);
138 down(&dev->struct_sem);
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 up(&dev->struct_sem);
154 up(&dev->struct_sem);
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 spinlock_t lock = SPIN_LOCK_UNLOCKED;
179 drm_file_t *priv = filp->private_data;
180 drm_device_t *dev = priv->dev;
183 /* Find unique magic */
185 auth.magic = priv->magic;
189 if (!sequence) ++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->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);