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 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 /** @file drm_auth.c 35 * Implementation of the get/authmagic ioctls implementing the authentication 36 * scheme between the master and clients. 37 */ 38 39 #include <dev/drm2/drmP.h> 40 41 static int drm_hash_magic(drm_magic_t magic) 42 { 43 return magic & (DRM_HASH_SIZE-1); 44 } 45 46 /** 47 * Returns the file private associated with the given magic number. 48 */ 49 static struct drm_file *drm_find_file(struct drm_device *dev, drm_magic_t magic) 50 { 51 drm_magic_entry_t *pt; 52 int hash = drm_hash_magic(magic); 53 54 DRM_LOCK_ASSERT(dev); 55 56 for (pt = dev->magiclist[hash].head; pt; pt = pt->next) { 57 if (pt->magic == magic) { 58 return pt->priv; 59 } 60 } 61 62 return NULL; 63 } 64 65 /** 66 * Inserts the given magic number into the hash table of used magic number 67 * lists. 68 */ 69 static int drm_add_magic(struct drm_device *dev, struct drm_file *priv, 70 drm_magic_t magic) 71 { 72 int hash; 73 drm_magic_entry_t *entry; 74 75 DRM_DEBUG("%d\n", magic); 76 77 DRM_LOCK_ASSERT(dev); 78 79 hash = drm_hash_magic(magic); 80 entry = malloc(sizeof(*entry), DRM_MEM_MAGIC, M_ZERO | M_NOWAIT); 81 if (!entry) 82 return ENOMEM; 83 entry->magic = magic; 84 entry->priv = priv; 85 entry->next = NULL; 86 87 if (dev->magiclist[hash].tail) { 88 dev->magiclist[hash].tail->next = entry; 89 dev->magiclist[hash].tail = entry; 90 } else { 91 dev->magiclist[hash].head = entry; 92 dev->magiclist[hash].tail = entry; 93 } 94 95 return 0; 96 } 97 98 /** 99 * Removes the given magic number from the hash table of used magic number 100 * lists. 101 */ 102 static int drm_remove_magic(struct drm_device *dev, drm_magic_t magic) 103 { 104 drm_magic_entry_t *prev = NULL; 105 drm_magic_entry_t *pt; 106 int hash; 107 108 DRM_LOCK_ASSERT(dev); 109 110 DRM_DEBUG("%d\n", magic); 111 hash = drm_hash_magic(magic); 112 113 for (pt = dev->magiclist[hash].head; pt; prev = pt, pt = pt->next) { 114 if (pt->magic == magic) { 115 if (dev->magiclist[hash].head == pt) { 116 dev->magiclist[hash].head = pt->next; 117 } 118 if (dev->magiclist[hash].tail == pt) { 119 dev->magiclist[hash].tail = prev; 120 } 121 if (prev) { 122 prev->next = pt->next; 123 } 124 free(pt, DRM_MEM_MAGIC); 125 return 0; 126 } 127 } 128 129 return EINVAL; 130 } 131 132 /** 133 * Called by the client, this returns a unique magic number to be authorized 134 * by the master. 135 * 136 * The master may use its own knowledge of the client (such as the X 137 * connection that the magic is passed over) to determine if the magic number 138 * should be authenticated. 139 */ 140 int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) 141 { 142 static drm_magic_t sequence = 0; 143 struct drm_auth *auth = data; 144 145 /* Find unique magic */ 146 if (file_priv->magic) { 147 auth->magic = file_priv->magic; 148 } else { 149 DRM_LOCK(dev); 150 do { 151 int old = sequence; 152 153 auth->magic = old+1; 154 155 if (!atomic_cmpset_int(&sequence, old, auth->magic)) 156 continue; 157 } while (drm_find_file(dev, auth->magic)); 158 file_priv->magic = auth->magic; 159 drm_add_magic(dev, file_priv, auth->magic); 160 DRM_UNLOCK(dev); 161 } 162 163 DRM_DEBUG("%u\n", auth->magic); 164 165 return 0; 166 } 167 168 /** 169 * Marks the client associated with the given magic number as authenticated. 170 */ 171 int drm_authmagic(struct drm_device *dev, void *data, 172 struct drm_file *file_priv) 173 { 174 struct drm_auth *auth = data; 175 struct drm_file *priv; 176 177 DRM_DEBUG("%u\n", auth->magic); 178 179 DRM_LOCK(dev); 180 priv = drm_find_file(dev, auth->magic); 181 if (priv != NULL) { 182 priv->authenticated = 1; 183 drm_remove_magic(dev, auth->magic); 184 DRM_UNLOCK(dev); 185 return 0; 186 } else { 187 DRM_UNLOCK(dev); 188 return EINVAL; 189 } 190 } 191