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 <sys/cdefs.h> 37 #include <dev/drm2/drmP.h> 38 39 static struct mtx drm_magic_lock; 40 41 /** 42 * Find the file with the given magic number. 43 * 44 * \param dev DRM device. 45 * \param magic magic number. 46 * 47 * Searches in drm_device::magiclist within all files with the same hash key 48 * the one with matching magic number, while holding the drm_device::struct_mutex 49 * lock. 50 */ 51 static struct drm_file *drm_find_file(struct drm_master *master, drm_magic_t magic) 52 { 53 struct drm_file *retval = NULL; 54 struct drm_magic_entry *pt; 55 struct drm_hash_item *hash; 56 struct drm_device *dev = master->minor->dev; 57 58 DRM_LOCK(dev); 59 if (!drm_ht_find_item(&master->magiclist, (unsigned long)magic, &hash)) { 60 pt = drm_hash_entry(hash, struct drm_magic_entry, hash_item); 61 retval = pt->priv; 62 } 63 DRM_UNLOCK(dev); 64 return retval; 65 } 66 67 /** 68 * Adds a magic number. 69 * 70 * \param dev DRM device. 71 * \param priv file private data. 72 * \param magic magic number. 73 * 74 * Creates a drm_magic_entry structure and appends to the linked list 75 * associated the magic number hash key in drm_device::magiclist, while holding 76 * the drm_device::struct_mutex lock. 77 */ 78 static int drm_add_magic(struct drm_master *master, struct drm_file *priv, 79 drm_magic_t magic) 80 { 81 struct drm_magic_entry *entry; 82 struct drm_device *dev = master->minor->dev; 83 DRM_DEBUG("%d\n", magic); 84 85 entry = malloc(sizeof(*entry), DRM_MEM_MAGIC, M_ZERO | M_NOWAIT); 86 if (!entry) 87 return -ENOMEM; 88 entry->priv = priv; 89 entry->hash_item.key = (unsigned long)magic; 90 DRM_LOCK(dev); 91 drm_ht_insert_item(&master->magiclist, &entry->hash_item); 92 list_add_tail(&entry->head, &master->magicfree); 93 DRM_UNLOCK(dev); 94 95 return 0; 96 } 97 98 /** 99 * Remove a magic number. 100 * 101 * \param dev DRM device. 102 * \param magic magic number. 103 * 104 * Searches and unlinks the entry in drm_device::magiclist with the magic 105 * number hash key, while holding the drm_device::struct_mutex lock. 106 */ 107 int drm_remove_magic(struct drm_master *master, drm_magic_t magic) 108 { 109 struct drm_magic_entry *pt; 110 struct drm_hash_item *hash; 111 struct drm_device *dev = master->minor->dev; 112 113 DRM_DEBUG("%d\n", magic); 114 115 DRM_LOCK(dev); 116 if (drm_ht_find_item(&master->magiclist, (unsigned long)magic, &hash)) { 117 DRM_UNLOCK(dev); 118 return -EINVAL; 119 } 120 pt = drm_hash_entry(hash, struct drm_magic_entry, hash_item); 121 drm_ht_remove_item(&master->magiclist, hash); 122 list_del(&pt->head); 123 DRM_UNLOCK(dev); 124 125 free(pt, DRM_MEM_MAGIC); 126 127 return 0; 128 } 129 130 /** 131 * Get a unique magic number (ioctl). 132 * 133 * \param inode device inode. 134 * \param file_priv DRM file private. 135 * \param cmd command. 136 * \param arg pointer to a resulting drm_auth structure. 137 * \return zero on success, or a negative number on failure. 138 * 139 * If there is a magic number in drm_file::magic then use it, otherwise 140 * searches an unique non-zero magic number and add it associating it with \p 141 * file_priv. 142 * This ioctl needs protection by the drm_global_mutex, which protects 143 * struct drm_file::magic and struct drm_magic_entry::priv. 144 */ 145 int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) 146 { 147 static drm_magic_t sequence = 0; 148 struct drm_auth *auth = data; 149 150 /* Find unique magic */ 151 if (file_priv->magic) { 152 auth->magic = file_priv->magic; 153 } else { 154 do { 155 mtx_lock(&drm_magic_lock); 156 if (!sequence) 157 ++sequence; /* reserve 0 */ 158 auth->magic = sequence++; 159 mtx_unlock(&drm_magic_lock); 160 } while (drm_find_file(file_priv->master, auth->magic)); 161 file_priv->magic = auth->magic; 162 drm_add_magic(file_priv->master, file_priv, auth->magic); 163 } 164 165 DRM_DEBUG("%u\n", auth->magic); 166 167 return 0; 168 } 169 170 /** 171 * Authenticate with a magic. 172 * 173 * \param inode device inode. 174 * \param file_priv DRM file private. 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 file_priv is associated with the magic number passed in \arg. 180 * This ioctl needs protection by the drm_global_mutex, which protects 181 * struct drm_file::magic and struct drm_magic_entry::priv. 182 */ 183 int drm_authmagic(struct drm_device *dev, void *data, 184 struct drm_file *file_priv) 185 { 186 struct drm_auth *auth = data; 187 struct drm_file *file; 188 189 DRM_DEBUG("%u\n", auth->magic); 190 if ((file = drm_find_file(file_priv->master, auth->magic))) { 191 file->authenticated = 1; 192 drm_remove_magic(file_priv->master, auth->magic); 193 return 0; 194 } 195 return -EINVAL; 196 } 197 198 static int 199 drm_magic_init(void *arg) 200 { 201 202 mtx_init(&drm_magic_lock, "drm_getmagic__lock", NULL, MTX_DEF); 203 return (0); 204 } 205 206 static void 207 drm_magic_fini(void *arg) 208 { 209 210 mtx_destroy(&drm_magic_lock); 211 } 212 213 SYSINIT(drm_magic_init, SI_SUB_KLD, SI_ORDER_MIDDLE, drm_magic_init, NULL); 214 SYSUNINIT(drm_magic_fini, SI_SUB_KLD, SI_ORDER_MIDDLE, drm_magic_fini, NULL); 215