diff options
Diffstat (limited to 'drivers/char/drm/drm_auth.c')
| -rw-r--r-- | drivers/char/drm/drm_auth.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/char/drm/drm_auth.c b/drivers/char/drm/drm_auth.c new file mode 100644 index 000000000000..b428761c4e91 --- /dev/null +++ b/drivers/char/drm/drm_auth.c @@ -0,0 +1,230 @@ +/** + * \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->head->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->head->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; +} |