--- /dev/null
+/**
+ * \file drm_auth.h
+ * IOCTLs for authentication
+ *
+ * \author Rickard E. (Rik) Faith <faith@valinux.com>
+ * \author Gareth Hughes <gareth@valinux.com>
+ */
+
+/*
+ * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com
+ *
+ * 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 "drmP.h"
+
+/**
+ * Generate a hash key from a magic.
+ *
+ * \param magic magic.
+ * \return hash key.
+ *
+ * The key is the modulus of the hash table size, #DRM_HASH_SIZE, which must be
+ * a power of 2.
+ */
+static int drm_hash_magic(drm_magic_t magic)
+{
+ return magic & (DRM_HASH_SIZE-1);
+}
+
+/**
+ * Find the file with the given magic number.
+ *
+ * \param dev DRM device.
+ * \param magic magic number.
+ *
+ * Searches in drm_device::magiclist within all files with the same hash key
+ * the one with matching magic number, while holding the drm_device::struct_sem
+ * lock.
+ */
+static drm_file_t *drm_find_file(drm_device_t *dev, drm_magic_t magic)
+{
+ drm_file_t *retval = NULL;
+ drm_magic_entry_t *pt;
+ int hash = drm_hash_magic(magic);
+
+ down(&dev->struct_sem);
+ for (pt = dev->magiclist[hash].head; pt; pt = pt->next) {
+ if (pt->magic == magic) {
+ retval = pt->priv;
+ break;
+ }
+ }
+ up(&dev->struct_sem);
+ return retval;
+}
+
+/**
+ * Adds a magic number.
+ *
+ * \param dev DRM device.
+ * \param priv file private data.
+ * \param magic magic number.
+ *
+ * Creates a drm_magic_entry structure and appends to the linked list
+ * associated the magic number hash key in drm_device::magiclist, while holding
+ * the drm_device::struct_sem lock.
+ */
+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);
+
+ hash = drm_hash_magic(magic);
+ entry = drm_alloc(sizeof(*entry), DRM_MEM_MAGIC);
+ if (!entry) return -ENOMEM;
+ memset(entry, 0, sizeof(*entry));
+ entry->magic = magic;
+ entry->priv = priv;
+ entry->next = NULL;
+
+ down(&dev->struct_sem);
+ 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;
+ }
+ up(&dev->struct_sem);
+
+ return 0;
+}
+
+/**
+ * Remove a magic number.
+ *
+ * \param dev DRM device.
+ * \param magic magic number.
+ *
+ * Searches and unlinks the entry in drm_device::magiclist with the magic
+ * number hash key, while holding the drm_device::struct_sem lock.
+ */
+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_DEBUG("%d\n", magic);
+ hash = drm_hash_magic(magic);
+
+ down(&dev->struct_sem);
+ 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;
+ }
+ up(&dev->struct_sem);
+ return 0;
+ }
+ }
+ up(&dev->struct_sem);
+
+ drm_free(pt, sizeof(*pt), DRM_MEM_MAGIC);
+
+ return -EINVAL;
+}
+
+/**
+ * Get a unique magic number (ioctl).
+ *
+ * \param inode device inode.
+ * \param filp file pointer.
+ * \param cmd command.
+ * \param arg pointer to a resulting drm_auth structure.
+ * \return zero on success, or a negative number on failure.
+ *
+ * If there is a magic number in drm_file::magic then use it, otherwise
+ * searches an unique non-zero magic number and add it associating it with \p
+ * filp.
+ */
+int drm_getmagic(struct inode *inode, struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ static drm_magic_t sequence = 0;
+ static DEFINE_SPINLOCK(lock);
+ drm_file_t *priv = filp->private_data;
+ drm_device_t *dev = priv->dev;
+ drm_auth_t auth;
+
+ /* Find unique magic */
+ if (priv->magic) {
+ auth.magic = priv->magic;
+ } else {
+ do {
+ spin_lock(&lock);
+ if (!sequence) ++sequence; /* reserve 0 */
+ auth.magic = sequence++;
+ spin_unlock(&lock);
+ } while (drm_find_file(dev, auth.magic));
+ priv->magic = auth.magic;
+ drm_add_magic(dev, priv, auth.magic);
+ }
+
+ DRM_DEBUG("%u\n", auth.magic);
+ if (copy_to_user((drm_auth_t __user *)arg, &auth, sizeof(auth)))
+ return -EFAULT;
+ return 0;
+}
+
+/**
+ * Authenticate with a magic.
+ *
+ * \param inode device inode.
+ * \param filp file pointer.
+ * \param cmd command.
+ * \param arg pointer to a drm_auth structure.
+ * \return zero if authentication successed, or a negative number otherwise.
+ *
+ * Checks if \p filp is associated with the magic number passed in \arg.
+ */
+int drm_authmagic(struct inode *inode, struct file *filp,
+ unsigned int cmd, unsigned long arg)
+{
+ drm_file_t *priv = filp->private_data;
+ drm_device_t *dev = priv->dev;
+ drm_auth_t auth;
+ drm_file_t *file;
+
+ if (copy_from_user(&auth, (drm_auth_t __user *)arg, sizeof(auth)))
+ return -EFAULT;
+ DRM_DEBUG("%u\n", auth.magic);
+ if ((file = drm_find_file(dev, auth.magic))) {
+ file->authenticated = 1;
+ drm_remove_magic(dev, auth.magic);
+ return 0;
+ }
+ return -EINVAL;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff