/** * \file drm_auth.c * 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 <sys/cdefs.h> #include <dev/drm2/drmP.h> static struct mtx drm_magic_lock; /** * 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_mutex * lock. */ 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; DRM_LOCK(dev); 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; } DRM_UNLOCK(dev); 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_mutex lock. */ 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 = malloc(sizeof(*entry), DRM_MEM_MAGIC, M_ZERO | M_NOWAIT); if (!entry) return -ENOMEM; entry->priv = priv; entry->hash_item.key = (unsigned long)magic; DRM_LOCK(dev); drm_ht_insert_item(&master->magiclist, &entry->hash_item); list_add_tail(&entry->head, &master->magicfree); DRM_UNLOCK(dev); 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_mutex lock. */ 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); DRM_LOCK(dev); if (drm_ht_find_item(&master->magiclist, (unsigned long)magic, &hash)) { DRM_UNLOCK(dev); return -EINVAL; } pt = drm_hash_entry(hash, struct drm_magic_entry, hash_item); drm_ht_remove_item(&master->magiclist, hash); list_del(&pt->head); DRM_UNLOCK(dev); free(pt, DRM_MEM_MAGIC); return 0; } /** * Get a unique magic number (ioctl). * * \param inode device inode. * \param file_priv DRM file private. * \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 * file_priv. * This ioctl needs protection by the drm_global_mutex, which protects * struct drm_file::magic and struct drm_magic_entry::priv. */ int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) { static drm_magic_t sequence = 0; struct drm_auth *auth = data; /* Find unique magic */ if (file_priv->magic) { auth->magic = file_priv->magic; } else { do { mtx_lock(&drm_magic_lock); if (!sequence) ++sequence; /* reserve 0 */ auth->magic = sequence++; mtx_unlock(&drm_magic_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; } /** * Authenticate with a magic. * * \param inode device inode. * \param file_priv DRM file private. * \param cmd command. * \param arg pointer to a drm_auth structure. * \return zero if authentication successed, or a negative number otherwise. * * Checks if \p file_priv is associated with the magic number passed in \arg. * This ioctl needs protection by the drm_global_mutex, which protects * struct drm_file::magic and struct drm_magic_entry::priv. */ 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; } static int drm_magic_init(void *arg) { mtx_init(&drm_magic_lock, "drm_getmagic__lock", NULL, MTX_DEF); return (0); } static void drm_magic_fini(void *arg) { mtx_destroy(&drm_magic_lock); } SYSINIT(drm_magic_init, SI_SUB_KLD, SI_ORDER_MIDDLE, drm_magic_init, NULL); SYSUNINIT(drm_magic_fini, SI_SUB_KLD, SI_ORDER_MIDDLE, drm_magic_fini, NULL);
