1 /*- 2 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas. 3 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California. 4 * All Rights Reserved. 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a 7 * copy of this software and associated documentation files (the "Software"), 8 * to deal in the Software without restriction, including without limitation 9 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 10 * and/or sell copies of the Software, and to permit persons to whom the 11 * Software is furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice (including the next 14 * paragraph) shall be included in all copies or substantial portions of the 15 * Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR 21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 23 * OTHER DEALINGS IN THE SOFTWARE. 24 * 25 * Authors: 26 * Rickard E. (Rik) Faith <faith@valinux.com> 27 * Gareth Hughes <gareth@valinux.com> 28 * 29 */ 30 31 /** @file drm_auth.c 32 * Implementation of the get/authmagic ioctls implementing the authentication 33 * scheme between the master and clients. 34 */ 35 36 #include "dev/drm/drmP.h" 37 38 static int drm_hash_magic(drm_magic_t magic) 39 { 40 return magic & (DRM_HASH_SIZE-1); 41 } 42 43 /** 44 * Returns the file private associated with the given magic number. 45 */ 46 static struct drm_file *drm_find_file(struct drm_device *dev, drm_magic_t magic) 47 { 48 drm_magic_entry_t *pt; 49 int hash = drm_hash_magic(magic); 50 51 DRM_SPINLOCK_ASSERT(&dev->dev_lock); 52 53 for (pt = dev->magiclist[hash].head; pt; pt = pt->next) { 54 if (pt->magic == magic) { 55 return pt->priv; 56 } 57 } 58 59 return NULL; 60 } 61 62 /** 63 * Inserts the given magic number into the hash table of used magic number 64 * lists. 65 */ 66 static int drm_add_magic(struct drm_device *dev, struct drm_file *priv, 67 drm_magic_t magic) 68 { 69 int hash; 70 drm_magic_entry_t *entry; 71 72 DRM_DEBUG("%d\n", magic); 73 74 DRM_SPINLOCK_ASSERT(&dev->dev_lock); 75 76 hash = drm_hash_magic(magic); 77 entry = malloc(sizeof(*entry), DRM_MEM_MAGIC, M_ZERO | M_NOWAIT); 78 if (!entry) 79 return ENOMEM; 80 entry->magic = magic; 81 entry->priv = priv; 82 entry->next = NULL; 83 84 if (dev->magiclist[hash].tail) { 85 dev->magiclist[hash].tail->next = entry; 86 dev->magiclist[hash].tail = entry; 87 } else { 88 dev->magiclist[hash].head = entry; 89 dev->magiclist[hash].tail = entry; 90 } 91 92 return 0; 93 } 94 95 /** 96 * Removes the given magic number from the hash table of used magic number 97 * lists. 98 */ 99 static int drm_remove_magic(struct drm_device *dev, drm_magic_t magic) 100 { 101 drm_magic_entry_t *prev = NULL; 102 drm_magic_entry_t *pt; 103 int hash; 104 105 DRM_SPINLOCK_ASSERT(&dev->dev_lock); 106 107 DRM_DEBUG("%d\n", magic); 108 hash = drm_hash_magic(magic); 109 110 for (pt = dev->magiclist[hash].head; pt; prev = pt, pt = pt->next) { 111 if (pt->magic == magic) { 112 if (dev->magiclist[hash].head == pt) { 113 dev->magiclist[hash].head = pt->next; 114 } 115 if (dev->magiclist[hash].tail == pt) { 116 dev->magiclist[hash].tail = prev; 117 } 118 if (prev) { 119 prev->next = pt->next; 120 } 121 free(pt, DRM_MEM_MAGIC); 122 return 0; 123 } 124 } 125 126 return EINVAL; 127 } 128 129 /** 130 * Called by the client, this returns a unique magic number to be authorized 131 * by the master. 132 * 133 * The master may use its own knowledge of the client (such as the X 134 * connection that the magic is passed over) to determine if the magic number 135 * should be authenticated. 136 */ 137 int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) 138 { 139 static drm_magic_t sequence = 0; 140 struct drm_auth *auth = data; 141 142 /* Find unique magic */ 143 if (file_priv->magic) { 144 auth->magic = file_priv->magic; 145 } else { 146 DRM_LOCK(); 147 do { 148 int old = sequence; 149 150 auth->magic = old+1; 151 152 if (!atomic_cmpset_int(&sequence, old, auth->magic)) 153 continue; 154 } while (drm_find_file(dev, auth->magic)); 155 file_priv->magic = auth->magic; 156 drm_add_magic(dev, file_priv, auth->magic); 157 DRM_UNLOCK(); 158 } 159 160 DRM_DEBUG("%u\n", auth->magic); 161 162 return 0; 163 } 164 165 /** 166 * Marks the client associated with the given magic number as authenticated. 167 */ 168 int drm_authmagic(struct drm_device *dev, void *data, 169 struct drm_file *file_priv) 170 { 171 struct drm_auth *auth = data; 172 struct drm_file *priv; 173 174 DRM_DEBUG("%u\n", auth->magic); 175 176 DRM_LOCK(); 177 priv = drm_find_file(dev, auth->magic); 178 if (priv != NULL) { 179 priv->authenticated = 1; 180 drm_remove_magic(dev, auth->magic); 181 DRM_UNLOCK(); 182 return 0; 183 } else { 184 DRM_UNLOCK(); 185 return EINVAL; 186 } 187 } 188