LXR linux-old/drivers/char/drm/drm

   1/* drm_auth.h -- IOCTLs for authentication -*- linux-c -*-
   2 * Created: Tue Feb  2 08:37:54 1999 by faith@valinux.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 * VA LINUX SYSTEMS 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
  25 * OTHER DEALINGS IN THE SOFTWARE.
  26 *
  27 * Authors:
  28 *    Rickard E. (Rik) Faith <faith@valinux.com>
  29 *    Gareth Hughes <gareth@valinux.com>
  30 */
  31
  32#define __NO_VERSION__
  33#include "drmP.h"
  34
  35static int DRM(hash_magic)(drm_magic_t magic)
  36{
  37        return magic & (DRM_HASH_SIZE-1);
  38}
  39
  40static 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
  57int 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
  84int 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
 116int DRM(getmagic)(struct inode *inode, struct file *filp,
 117                  unsigned int cmd, 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
 145int DRM(authmagic)(struct inode *inode, struct file *filp,
 146                   unsigned int cmd, 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}
 163