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 * $FreeBSD: src/sys/dev/drm2/drm_auth.c,v 1.1 2012/05/22 11:07:44 kib Exp $ 30 */ 31 32 /** @file drm_auth.c 33 * Implementation of the get/authmagic ioctls implementing the authentication 34 * scheme between the master and clients. 35 */ 36 37 #include <drm/drmP.h> 38 39 static int drm_hash_magic(drm_magic_t magic) 40 { 41 return magic & (DRM_HASH_SIZE-1); 42 } 43 44 /** 45 * Returns the file private associated with the given magic number. 46 */ 47 static struct drm_file *drm_find_file(struct drm_device *dev, drm_magic_t magic) 48 { 49 drm_magic_entry_t *pt; 50 int hash = drm_hash_magic(magic); 51 52 DRM_LOCK_ASSERT(dev); 53 54 for (pt = dev->magiclist[hash].head; pt; pt = pt->next) { 55 if (pt->magic == magic) { 56 return pt->priv; 57 } 58 } 59 60 return NULL; 61 } 62 63 /** 64 * Inserts the given magic number into the hash table of used magic number 65 * lists. 66 */ 67 static int drm_add_magic(struct drm_device *dev, struct drm_file *priv, 68 drm_magic_t magic) 69 { 70 int hash; 71 drm_magic_entry_t *entry; 72 73 DRM_DEBUG("%d\n", magic); 74 75 DRM_LOCK_ASSERT(dev); 76 77 hash = drm_hash_magic(magic); 78 entry = kmalloc(sizeof(*entry), DRM_MEM_MAGIC, M_ZERO | M_NOWAIT); 79 if (!entry) 80 return ENOMEM; 81 entry->magic = magic; 82 entry->priv = priv; 83 entry->next = NULL; 84 85 if (dev->magiclist[hash].tail) { 86 dev->magiclist[hash].tail->next = entry; 87 dev->magiclist[hash].tail = entry; 88 } else { 89 dev->magiclist[hash].head = entry; 90 dev->magiclist[hash].tail = entry; 91 } 92 93 return 0; 94 } 95 96 /** 97 * Removes the given magic number from the hash table of used magic number 98 * lists. 99 */ 100 static int drm_remove_magic(struct drm_device *dev, drm_magic_t magic) 101 { 102 drm_magic_entry_t *prev = NULL; 103 drm_magic_entry_t *pt; 104 int hash; 105 106 DRM_LOCK_ASSERT(dev); 107 108 DRM_DEBUG("%d\n", magic); 109 hash = drm_hash_magic(magic); 110 111 for (pt = dev->magiclist[hash].head; pt; prev = pt, pt = pt->next) { 112 if (pt->magic == magic) { 113 if (dev->magiclist[hash].head == pt) { 114 dev->magiclist[hash].head = pt->next; 115 } 116 if (dev->magiclist[hash].tail == pt) { 117 dev->magiclist[hash].tail = prev; 118 } 119 if (prev) { 120 prev->next = pt->next; 121 } 122 drm_free(pt, DRM_MEM_MAGIC); 123 return 0; 124 } 125 } 126 127 return EINVAL; 128 } 129 130 /** 131 * Called by the client, this returns a unique magic number to be authorized 132 * by the master. 133 * 134 * The master may use its own knowledge of the client (such as the X 135 * connection that the magic is passed over) to determine if the magic number 136 * should be authenticated. 137 */ 138 int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv) 139 { 140 static drm_magic_t sequence = 0; 141 struct drm_auth *auth = data; 142 143 /* Find unique magic */ 144 if (file_priv->magic) { 145 auth->magic = file_priv->magic; 146 } else { 147 DRM_LOCK(dev); 148 do { 149 int old = sequence; 150 151 auth->magic = old+1; 152 153 if (!atomic_cmpset_int(&sequence, old, auth->magic)) 154 continue; 155 } while (drm_find_file(dev, auth->magic)); 156 file_priv->magic = auth->magic; 157 drm_add_magic(dev, file_priv, auth->magic); 158 DRM_UNLOCK(dev); 159 } 160 161 DRM_DEBUG("%u\n", auth->magic); 162 163 return 0; 164 } 165 166 /** 167 * Marks the client associated with the given magic number as authenticated. 168 */ 169 int drm_authmagic(struct drm_device *dev, void *data, 170 struct drm_file *file_priv) 171 { 172 struct drm_auth *auth = data; 173 struct drm_file *priv; 174 175 DRM_DEBUG("%u\n", auth->magic); 176 177 DRM_LOCK(dev); 178 priv = drm_find_file(dev, auth->magic); 179 if (priv != NULL) { 180 priv->authenticated = 1; 181 drm_remove_magic(dev, auth->magic); 182 DRM_UNLOCK(dev); 183 return 0; 184 } else { 185 DRM_UNLOCK(dev); 186 return EINVAL; 187 } 188 } 189