drm_auth.c

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/*
 * Created: Tue Feb  2 08:37:54 1999 by [email protected]
 *
 * 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.
 */

#include <drm/drmP.h>

static struct drm_file *drm_find_file(struct drm_master *master, drm_magic_t magic)
{
    struct drm_file *retval = NULL;
    struct drm_magic_entry *pt;
    struct drm_hash_item *hash;
    struct drm_device *dev = master->minor->dev;

    mutex_lock(&dev->struct_mutex);
    if (!drm_ht_find_item(&master->magiclist, (unsigned long)magic, &hash)) {
        pt = drm_hash_entry(hash, struct drm_magic_entry, hash_item);
        retval = pt->priv;
    }
    mutex_unlock(&dev->struct_mutex);
    return retval;
}

static int drm_add_magic(struct drm_master *master, struct drm_file *priv,
             drm_magic_t magic)
{
    struct drm_magic_entry *entry;
    struct drm_device *dev = master->minor->dev;
    DRM_DEBUG("%d\n", magic);

    entry = kzalloc(sizeof(*entry), GFP_KERNEL);
    if (!entry)
        return -ENOMEM;
    entry->priv = priv;
    entry->hash_item.key = (unsigned long)magic;
    mutex_lock(&dev->struct_mutex);
    drm_ht_insert_item(&master->magiclist, &entry->hash_item);
    list_add_tail(&entry->head, &master->magicfree);
    mutex_unlock(&dev->struct_mutex);

    return 0;
}

int drm_remove_magic(struct drm_master *master, drm_magic_t magic)
{
    struct drm_magic_entry *pt;
    struct drm_hash_item *hash;
    struct drm_device *dev = master->minor->dev;

    DRM_DEBUG("%d\n", magic);

    mutex_lock(&dev->struct_mutex);
    if (drm_ht_find_item(&master->magiclist, (unsigned long)magic, &hash)) {
        mutex_unlock(&dev->struct_mutex);
        return -EINVAL;
    }
    pt = drm_hash_entry(hash, struct drm_magic_entry, hash_item);
    drm_ht_remove_item(&master->magiclist, hash);
    list_del(&pt->head);
    mutex_unlock(&dev->struct_mutex);

    kfree(pt);

    return 0;
}

int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
    static drm_magic_t sequence = 0;
    static DEFINE_SPINLOCK(lock);
    struct drm_auth *auth = data;

    /* Find unique magic */
    if (file_priv->magic) {
        auth->magic = file_priv->magic;
    } else {
        do {
            spin_lock(&lock);
            if (!sequence)
                ++sequence; /* reserve 0 */
            auth->magic = sequence++;
            spin_unlock(&lock);
        } while (drm_find_file(file_priv->master, auth->magic));
        file_priv->magic = auth->magic;
        drm_add_magic(file_priv->master, file_priv, auth->magic);
    }

    DRM_DEBUG("%u\n", auth->magic);

    return 0;
}

int drm_authmagic(struct drm_device *dev, void *data,
          struct drm_file *file_priv)
{
    struct drm_auth *auth = data;
    struct drm_file *file;

    DRM_DEBUG("%u\n", auth->magic);
    if ((file = drm_find_file(file_priv->master, auth->magic))) {
        file->authenticated = 1;
        drm_remove_magic(file_priv->master, auth->magic);
        return 0;
    }
    return -EINVAL;
}