1494N/A/*
1494N/A * Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved.
1494N/A */
1494N/A
1494N/A/*
1494N/A * Copyright (c) 2012 Intel Corporation. All rights reserved.
1494N/A */
1494N/A
1494N/A/**
1494N/A * \file drm_auth.c
1494N/A * IOCTLs for authentication
1494N/A *
1494N/A * \author Rickard E. (Rik) Faith <faith@valinux.com>
1494N/A * \author Gareth Hughes <gareth@valinux.com>
1494N/A */
1494N/A
1494N/A/*
1494N/A * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com
1494N/A *
1494N/A * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
1494N/A * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
1494N/A * All Rights Reserved.
1494N/A *
1494N/A * Permission is hereby granted, free of charge, to any person obtaining a
1494N/A * copy of this software and associated documentation files (the "Software"),
1494N/A * to deal in the Software without restriction, including without limitation
1494N/A * the rights to use, copy, modify, merge, publish, distribute, sublicense,
1494N/A * and/or sell copies of the Software, and to permit persons to whom the
1494N/A * Software is furnished to do so, subject to the following conditions:
1494N/A *
1494N/A * The above copyright notice and this permission notice (including the next
1494N/A * paragraph) shall be included in all copies or substantial portions of the
1494N/A * Software.
1494N/A *
1494N/A * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
1494N/A * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
1494N/A * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
1494N/A * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
1494N/A * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
1494N/A * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
1494N/A * OTHER DEALINGS IN THE SOFTWARE.
1494N/A */
1494N/A
1494N/A#include "drmP.h"
1494N/A
1494N/A/**
1494N/A * Generate a hash key from a magic.
1494N/A *
1494N/A * \param magic magic.
1494N/A * \return hash key.
1494N/A *
1494N/A * The key is the modulus of the hash table size, #DRM_HASH_SIZE, which must be
1494N/A * a power of 2.
1494N/A */
1494N/Astatic int drm_hash_magic(drm_magic_t magic)
1494N/A{
1494N/A return magic & (DRM_HASH_SIZE - 1);
1494N/A}
1494N/A
1494N/A/**
1494N/A * Find the file with the given magic number.
1494N/A *
1494N/A * \param dev DRM device.
1494N/A * \param magic magic number.
1494N/A *
1494N/A * Searches in drm_device::magiclist within all files with the same hash key
1494N/A * the one with matching magic number, while holding the drm_device::struct_mutex
1494N/A * lock.
1494N/A */
1494N/Astatic struct drm_file *drm_find_file(struct drm_master *master, drm_magic_t magic)
1494N/A{
1494N/A struct drm_file *retval = NULL;
1494N/A struct drm_magic_entry *pt;
1494N/A int hash = drm_hash_magic(magic);
1494N/A struct drm_device *dev = master->minor->dev;
1494N/A
1494N/A mutex_lock(&dev->struct_mutex);
1494N/A for (pt = master->magiclist[hash].head; pt; pt = pt->next) {
1494N/A if (pt->magic == magic) {
1494N/A retval = pt->priv;
1494N/A break;
1494N/A }
1494N/A }
1494N/A mutex_unlock(&dev->struct_mutex);
1494N/A return retval;
1494N/A}
1494N/A
1494N/A/**
1494N/A * Adds a magic number.
1494N/A *
1494N/A * \param dev DRM device.
1494N/A * \param priv file private data.
1494N/A * \param magic magic number.
1494N/A *
1494N/A * Creates a drm_magic_entry structure and appends to the linked list
1494N/A * associated the magic number hash key in drm_device::magiclist, while holding
1494N/A * the drm_device::struct_mutex lock.
1494N/A */
1494N/Astatic int drm_add_magic(struct drm_master *master, struct drm_file *priv,
1494N/A drm_magic_t magic)
1494N/A{
1494N/A int hash;
1494N/A struct drm_magic_entry *entry;
1494N/A struct drm_device *dev = master->minor->dev;
1494N/A
1494N/A DRM_DEBUG("%d\n", magic);
1494N/A
1494N/A hash = drm_hash_magic(magic);
1494N/A entry = drm_alloc(sizeof(*entry), DRM_MEM_MAGIC);
1494N/A if (!entry)
1494N/A return -ENOMEM;
1494N/A (void) memset(entry, 0, sizeof(*entry));
1494N/A entry->magic = magic;
1494N/A entry->priv = priv;
1494N/A entry->next = NULL;
1494N/A
1494N/A mutex_lock(&dev->struct_mutex);
1494N/A if (master->magiclist[hash].tail) {
1494N/A master->magiclist[hash].tail->next = entry;
1494N/A master->magiclist[hash].tail = entry;
1494N/A } else {
1494N/A master->magiclist[hash].head = entry;
1494N/A master->magiclist[hash].tail = entry;
1494N/A }
1494N/A mutex_unlock(&dev->struct_mutex);
1494N/A
1494N/A return 0;
1494N/A}
1494N/A
1494N/A/**
1494N/A * Remove a magic number.
1494N/A *
1494N/A * \param dev DRM device.
1494N/A * \param magic magic number.
1494N/A *
1494N/A * Searches and unlinks the entry in drm_device::magiclist with the magic
1494N/A * number hash key, while holding the drm_device::struct_mutex lock.
1494N/A */
1494N/Aint drm_remove_magic(struct drm_master *master, drm_magic_t magic)
1494N/A{
1494N/A struct drm_magic_entry *prev = NULL;
1494N/A struct drm_magic_entry *pt;
1494N/A int hash;
1494N/A struct drm_device *dev = master->minor->dev;
1494N/A
1494N/A DRM_DEBUG("%d\n", magic);
1494N/A hash = drm_hash_magic(magic);
1494N/A
1494N/A mutex_lock(&dev->struct_mutex);
1494N/A for (pt = master->magiclist[hash].head; pt; prev = pt, pt = pt->next) {
1494N/A if (pt->magic == magic) {
1494N/A if (master->magiclist[hash].head == pt) {
1494N/A master->magiclist[hash].head = pt->next;
1494N/A }
1494N/A if (master->magiclist[hash].tail == pt) {
1494N/A master->magiclist[hash].tail = prev;
1494N/A }
1494N/A if (prev) {
1494N/A prev->next = pt->next;
1494N/A }
1494N/A mutex_unlock(&dev->struct_mutex);
1494N/A drm_free(pt, sizeof (*pt), DRM_MEM_MAGIC);
1494N/A return 0;
1494N/A }
1494N/A }
1494N/A mutex_unlock(&dev->struct_mutex);
1494N/A
1494N/A return -EINVAL;
1494N/A}
1494N/A
1494N/A/**
1494N/A * Get a unique magic number (ioctl).
1494N/A *
1494N/A * \param inode device inode.
1494N/A * \param file_priv DRM file private.
1494N/A * \param cmd command.
1494N/A * \param arg pointer to a resulting drm_auth structure.
1494N/A * \return zero on success, or a negative number on failure.
1494N/A *
1494N/A * If there is a magic number in drm_file::magic then use it, otherwise
1494N/A * searches an unique non-zero magic number and add it associating it with \p
1494N/A * file_priv.
1494N/A * This ioctl needs protection by the drm_global_mutex, which protects
1494N/A * struct drm_file::magic and struct drm_magic_entry::priv.
1494N/A */
1494N/A/* LINTED */
1494N/Aint drm_getmagic(DRM_IOCTL_ARGS)
1494N/A{
1494N/A static drm_magic_t sequence = 0;
1494N/A struct drm_auth *auth = data;
1494N/A
1494N/A /* Find unique magic */
1494N/A if (file->magic) {
1494N/A auth->magic = file->magic;
1494N/A } else {
1494N/A do {
1494N/A int old = sequence;
1494N/A auth->magic = old + 1;
1494N/A if (!atomic_cmpset_int(&sequence, old, auth->magic))
1494N/A continue;
1494N/A } while (drm_find_file(file->master, auth->magic));
1494N/A file->magic = auth->magic;
1494N/A (void) drm_add_magic(file->master, file, auth->magic);
1494N/A }
1494N/A
1494N/A DRM_DEBUG("%u\n", auth->magic);
1494N/A
1494N/A return 0;
1494N/A}
1494N/A
1494N/A/**
1494N/A * Authenticate with a magic.
1494N/A *
1494N/A * \param inode device inode.
1494N/A * \param file_priv DRM file private.
1494N/A * \param cmd command.
1494N/A * \param arg pointer to a drm_auth structure.
1494N/A * \return zero if authentication successed, or a negative number otherwise.
1494N/A *
1494N/A * Checks if \p file_priv is associated with the magic number passed in \arg.
1494N/A * This ioctl needs protection by the drm_global_mutex, which protects
1494N/A * struct drm_file::magic and struct drm_magic_entry::priv.
1494N/A */
1494N/A/* LINTED */
1494N/Aint drm_authmagic(DRM_IOCTL_ARGS)
1494N/A{
1494N/A struct drm_auth *auth = data;
1494N/A struct drm_file *file_priv;
1494N/A
1494N/A DRM_DEBUG("%u\n", auth->magic);
1494N/A if ((file_priv = drm_find_file(file->master, auth->magic))) {
1494N/A file_priv->authenticated = 1;
1494N/A (void) drm_remove_magic(file->master, auth->magic);
1494N/A return 0;
1494N/A }
1494N/A return -EINVAL;
1494N/A}