1/** 2 * \file drm_auth.c 3 * IOCTLs for authentication 4 * 5 * \author Rickard E. (Rik) Faith <faith@valinux.com> 6 * \author Gareth Hughes <gareth@valinux.com> 7 */ 8 9/* 10 * Created: Tue Feb 2 08:37:54 1999 by faith@valinux.com 11 * 12 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. 13 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 14 * All Rights Reserved. 15 * 16 * Permission is hereby granted, free of charge, to any person obtaining a 17 * copy of this software and associated documentation files (the "Software"), 18 * to deal in the Software without restriction, including without limitation 19 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 20 * and/or sell copies of the Software, and to permit persons to whom the 21 * Software is furnished to do so, subject to the following conditions: 22 * 23 * The above copyright notice and this permission notice (including the next 24 * paragraph) shall be included in all copies or substantial portions of the 25 * Software. 26 * 27 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 28 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 29 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 30 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 31 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 32 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 33 * OTHER DEALINGS IN THE SOFTWARE. 34 */ 35 36#include "drmP.h" 37 38/** 39 * Find the file with the given magic number. 40 * 41 * \param dev DRM device. 42 * \param magic magic number. 43 * 44 * Searches in drm_device::magiclist within all files with the same hash key 45 * the one with matching magic number, while holding the drm_device::struct_mutex 46 * lock. 47 */ 48static drm_file_t *drm_find_file(drm_device_t * dev, drm_magic_t magic) 49{ 50 drm_file_t *retval = NULL; 51 drm_magic_entry_t *pt; 52 drm_hash_item_t *hash; 53 54 mutex_lock(&dev->struct_mutex); 55 if (!drm_ht_find_item(&dev->magiclist, (unsigned long)magic, &hash)) { 56 pt = drm_hash_entry(hash, drm_magic_entry_t, hash_item); 57 retval = pt->priv; 58 } 59 mutex_unlock(&dev->struct_mutex); 60 return retval; 61} 62 63/** 64 * Adds a magic number. 65 * 66 * \param dev DRM device. 67 * \param priv file private data. 68 * \param magic magic number. 69 * 70 * Creates a drm_magic_entry structure and appends to the linked list 71 * associated the magic number hash key in drm_device::magiclist, while holding 72 * the drm_device::struct_mutex lock. 73 */ 74static int drm_add_magic(drm_device_t * dev, drm_file_t * priv, 75 drm_magic_t magic) 76{ 77 drm_magic_entry_t *entry; 78 79 DRM_DEBUG("%d\n", magic); 80 81 entry = drm_alloc(sizeof(*entry), DRM_MEM_MAGIC); 82 if (!entry) 83 return -ENOMEM; 84 memset(entry, 0, sizeof(*entry)); 85 entry->priv = priv; 86 87 entry->hash_item.key = (unsigned long)magic; 88 mutex_lock(&dev->struct_mutex); 89 drm_ht_insert_item(&dev->magiclist, &entry->hash_item); 90 list_add_tail(&entry->head, &dev->magicfree); 91 mutex_unlock(&dev->struct_mutex); 92 93 return 0; 94} 95 96/** 97 * Remove a magic number. 98 * 99 * \param dev DRM device. 100 * \param magic magic number. 101 * 102 * Searches and unlinks the entry in drm_device::magiclist with the magic 103 * number hash key, while holding the drm_device::struct_mutex lock. 104 */ 105static int drm_remove_magic(drm_device_t * dev, drm_magic_t magic) 106{ 107 drm_magic_entry_t *pt; 108 drm_hash_item_t *hash; 109 110 DRM_DEBUG("%d\n", magic); 111 112 mutex_lock(&dev->struct_mutex); 113 if (drm_ht_find_item(&dev->magiclist, (unsigned long)magic, &hash)) { 114 mutex_unlock(&dev->struct_mutex); 115 return -EINVAL; 116 } 117 pt = drm_hash_entry(hash, drm_magic_entry_t, hash_item); 118 drm_ht_remove_item(&dev->magiclist, hash); 119 list_del(&pt->head); 120 mutex_unlock(&dev->struct_mutex); 121 122 drm_free(pt, sizeof(*pt), DRM_MEM_MAGIC); 123 124 return 0; 125} 126 127/** 128 * Get a unique magic number (ioctl). 129 * 130 * \param inode device inode. 131 * \param filp file pointer. 132 * \param cmd command. 133 * \param arg pointer to a resulting drm_auth structure. 134 * \return zero on success, or a negative number on failure. 135 * 136 * If there is a magic number in drm_file::magic then use it, otherwise 137 * searches an unique non-zero magic number and add it associating it with \p 138 * filp. 139 */ 140int drm_getmagic(struct inode *inode, struct file *filp, 141 unsigned int cmd, unsigned long arg) 142{ 143 static drm_magic_t sequence = 0; 144 static DEFINE_SPINLOCK(lock); 145 drm_file_t *priv = filp->private_data; 146 drm_device_t *dev = priv->head->dev; 147 drm_auth_t auth; 148 149 /* Find unique magic */ 150 if (priv->magic) { 151 auth.magic = priv->magic; 152 } else { 153 do { 154 spin_lock(&lock); 155 if (!sequence) 156 ++sequence; /* reserve 0 */ 157 auth.magic = sequence++; 158 spin_unlock(&lock); 159 } while (drm_find_file(dev, auth.magic)); 160 priv->magic = auth.magic; 161 drm_add_magic(dev, priv, auth.magic); 162 } 163 164 DRM_DEBUG("%u\n", auth.magic); 165 if (copy_to_user((drm_auth_t __user *) arg, &auth, sizeof(auth))) 166 return -EFAULT; 167 return 0; 168} 169 170/** 171 * Authenticate with a magic. 172 * 173 * \param inode device inode. 174 * \param filp file pointer. 175 * \param cmd command. 176 * \param arg pointer to a drm_auth structure. 177 * \return zero if authentication successed, or a negative number otherwise. 178 * 179 * Checks if \p filp is associated with the magic number passed in \arg. 180 */ 181int drm_authmagic(struct inode *inode, struct file *filp, 182 unsigned int cmd, unsigned long arg) 183{ 184 drm_file_t *priv = filp->private_data; 185 drm_device_t *dev = priv->head->dev; 186 drm_auth_t auth; 187 drm_file_t *file; 188 189 if (copy_from_user(&auth, (drm_auth_t __user *) arg, sizeof(auth))) 190 return -EFAULT; 191 DRM_DEBUG("%u\n", auth.magic); 192 if ((file = drm_find_file(dev, auth.magic))) { 193 file->authenticated = 1; 194 drm_remove_magic(dev, auth.magic); 195 return 0; 196 } 197 return -EINVAL; 198} 199