drivers/char/drm/auth.c

   1 /* auth.c -- IOCTLs for authentication -*- linux-c -*-
   2  * Created: Tue Feb  2 08:37:54 1999 by faith@precisioninsight.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  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice (including the next
  16  * paragraph) shall be included in all copies or substantial portions of the
  17  * Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  22  * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  23  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  24  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  25  * DEALINGS IN THE SOFTWARE.
  26  *
  27  * Authors:
  28  *    Rickard E. (Rik) Faith <faith@valinux.com>
  29  *
  30  */
  31
  32 #define __NO_VERSION__
  33 #include "drmP.h"
  34
  35 static int drm_hash_magic(drm_magic_t magic)
  36 {
  37         return magic & (DRM_HASH_SIZE-1);
  38 }
  39
  40 static drm_file_t *drm_find_file(drm_device_t *dev, drm_magic_t magic)
  41 {
  42         drm_file_t        *retval = NULL;
  43         drm_magic_entry_t *pt;
  44         int               hash    = drm_hash_magic(magic);
  45
  46         down(&dev->struct_sem);
  47         for (pt = dev->magiclist[hash].head; pt; pt = pt->next) {
  48                 if (pt->magic == magic) {
  49                         retval = pt->priv;
  50                         break;
  51                 }
  52         }
  53         up(&dev->struct_sem);
  54         return retval;
  55 }
  56
  57 int drm_add_magic(drm_device_t *dev, drm_file_t *priv, drm_magic_t magic)
  58 {
  59         int               hash;
  60         drm_magic_entry_t *entry;
  61
  62         DRM_DEBUG("%d\n", magic);
  63
  64         hash         = drm_hash_magic(magic);
  65         entry        = drm_alloc(sizeof(*entry), DRM_MEM_MAGIC);
  66         if (!entry) return -ENOMEM;
  67         entry->magic = magic;
  68         entry->priv  = priv;
  69         entry->next  = NULL;
  70
  71         down(&dev->struct_sem);
  72         if (dev->magiclist[hash].tail) {
  73                 dev->magiclist[hash].tail->next = entry;
  74                 dev->magiclist[hash].tail       = entry;
  75         } else {
  76                 dev->magiclist[hash].head       = entry;
  77                 dev->magiclist[hash].tail       = entry;
  78         }
  79         up(&dev->struct_sem);
  80
  81         return 0;
  82 }
  83
  84 int drm_remove_magic(drm_device_t *dev, drm_magic_t magic)
  85 {
  86         drm_magic_entry_t *prev = NULL;
  87         drm_magic_entry_t *pt;
  88         int               hash;
  89
  90         DRM_DEBUG("%d\n", magic);
  91         hash = drm_hash_magic(magic);
  92
  93         down(&dev->struct_sem);
  94         for (pt = dev->magiclist[hash].head; pt; prev = pt, pt = pt->next) {
  95                 if (pt->magic == magic) {
  96                         if (dev->magiclist[hash].head == pt) {
  97                                 dev->magiclist[hash].head = pt->next;
  98                         }
  99                         if (dev->magiclist[hash].tail == pt) {
 100                                 dev->magiclist[hash].tail = prev;
 101                         }
 102                         if (prev) {
 103                                 prev->next = pt->next;
 104                         }
 105                         up(&dev->struct_sem);
 106                         return 0;
 107                 }
 108         }
 109         up(&dev->struct_sem);
 110
 111         drm_free(pt, sizeof(*pt), DRM_MEM_MAGIC);
 112
 113         return -EINVAL;
 114 }
 115
 116 int drm_getmagic(struct inode *inode, struct file *filp, unsigned int cmd,
 117                  unsigned long arg)
 118 {
 119         static drm_magic_t sequence = 0;
 120         static spinlock_t  lock     = SPIN_LOCK_UNLOCKED;
 121         drm_file_t         *priv    = filp->private_data;
 122         drm_device_t       *dev     = priv->dev;
 123         drm_auth_t         auth;
 124
 125                                 /* Find unique magic */
 126         if (priv->magic) {
 127                 auth.magic = priv->magic;
 128         } else {
 129                 do {
 130                         spin_lock(&lock);
 131                         if (!sequence) ++sequence; /* reserve 0 */
 132                         auth.magic = sequence++;
 133                         spin_unlock(&lock);
 134                 } while (drm_find_file(dev, auth.magic));
 135                 priv->magic = auth.magic;
 136                 drm_add_magic(dev, priv, auth.magic);
 137         }
 138
 139         DRM_DEBUG("%u\n", auth.magic);
 140         if (copy_to_user((drm_auth_t *)arg, &auth, sizeof(auth)))
 141                 return -EFAULT;
 142         return 0;
 143 }
 144
 145 int drm_authmagic(struct inode *inode, struct file *filp, unsigned int cmd,
 146                   unsigned long arg)
 147 {
 148         drm_file_t         *priv    = filp->private_data;
 149         drm_device_t       *dev     = priv->dev;
 150         drm_auth_t         auth;
 151         drm_file_t         *file;
 152
 153         if (copy_from_user(&auth, (drm_auth_t *)arg, sizeof(auth)))
 154                 return -EFAULT;
 155         DRM_DEBUG("%u\n", auth.magic);
 156         if ((file = drm_find_file(dev, auth.magic))) {
 157                 file->authenticated = 1;
 158                 drm_remove_magic(dev, auth.magic);
 159                 return 0;
 160         }
 161         return -EINVAL;
 162 }