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/*-
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors:
* Rickard E. (Rik) Faith <faith@valinux.com>
* Gareth Hughes <gareth@valinux.com>
*
*/
/** @file drm_auth.c
* Implementation of the get/authmagic ioctls implementing the authentication
* scheme between the master and clients.
*/
#include "drmP.h"
static int drm_hash_magic(drm_magic_t magic)
{
return magic & (DRM_HASH_SIZE-1);
}
/**
* Returns the file private associated with the given magic number.
*/
static drm_file_t *drm_find_file(drm_device_t *dev, drm_magic_t magic)
{
drm_magic_entry_t *pt;
int hash = drm_hash_magic(magic);
DRM_SPINLOCK_ASSERT(&dev->dev_lock);
for (pt = dev->magiclist[hash].head; pt; pt = pt->next) {
if (pt->magic == magic) {
return pt->priv;
}
}
return NULL;
}
/**
* Inserts the given magic number into the hash table of used magic number
* lists.
*/
static int drm_add_magic(drm_device_t *dev, drm_file_t *priv, drm_magic_t magic)
{
int hash;
drm_magic_entry_t *entry;
DRM_DEBUG("%d\n", magic);
DRM_SPINLOCK_ASSERT(&dev->dev_lock);
hash = drm_hash_magic(magic);
entry = malloc(sizeof(*entry), M_DRM, M_ZERO | M_NOWAIT);
if (!entry) return ENOMEM;
entry->magic = magic;
entry->priv = priv;
entry->next = NULL;
DRM_LOCK();
if (dev->magiclist[hash].tail) {
dev->magiclist[hash].tail->next = entry;
dev->magiclist[hash].tail = entry;
} else {
dev->magiclist[hash].head = entry;
dev->magiclist[hash].tail = entry;
}
DRM_UNLOCK();
return 0;
}
/**
* Removes the given magic number from the hash table of used magic number
* lists.
*/
static int drm_remove_magic(drm_device_t *dev, drm_magic_t magic)
{
drm_magic_entry_t *prev = NULL;
drm_magic_entry_t *pt;
int hash;
DRM_SPINLOCK_ASSERT(&dev->dev_lock);
DRM_DEBUG("%d\n", magic);
hash = drm_hash_magic(magic);
for (pt = dev->magiclist[hash].head; pt; prev = pt, pt = pt->next) {
if (pt->magic == magic) {
if (dev->magiclist[hash].head == pt) {
dev->magiclist[hash].head = pt->next;
}
if (dev->magiclist[hash].tail == pt) {
dev->magiclist[hash].tail = prev;
}
if (prev) {
prev->next = pt->next;
}
return 0;
}
}
free(pt, M_DRM);
return EINVAL;
}
/**
* Called by the client, this returns a unique magic number to be authorized
* by the master.
*
* The master may use its own knowledge of the client (such as the X
* connection that the magic is passed over) to determine if the magic number
* should be authenticated.
*/
int drm_getmagic(drm_device_t *dev, void *data, struct drm_file *file_priv)
{
static drm_magic_t sequence = 0;
drm_auth_t *auth = data;
/* Find unique magic */
if (file_priv->magic) {
auth->magic = file_priv->magic;
} else {
DRM_LOCK();
do {
int old = sequence;
auth->magic = old+1;
if (!atomic_cmpset_int(&sequence, old, auth->magic))
continue;
} while (drm_find_file(dev, auth->magic));
file_priv->magic = auth->magic;
drm_add_magic(dev, file_priv, auth->magic);
DRM_UNLOCK();
}
DRM_DEBUG("%u\n", auth->magic);
return 0;
}
/**
* Marks the client associated with the given magic number as authenticated.
*/
int drm_authmagic(drm_device_t *dev, void *data, struct drm_file *file_priv)
{
drm_auth_t *auth = data;
drm_file_t *priv;
DRM_DEBUG("%u\n", auth->magic);
DRM_LOCK();
priv = drm_find_file(dev, auth->magic);
if (priv != NULL) {
priv->authenticated = 1;
drm_remove_magic(dev, auth->magic);
DRM_UNLOCK();
return 0;
} else {
DRM_UNLOCK();
return EINVAL;
}
}
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