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 */
drm_find_file(struct drm_master * master,drm_magic_t magic)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 */
drm_add_magic(struct drm_master * master,struct drm_file * priv,drm_magic_t magic)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 */
drm_remove_magic(struct drm_master * master,drm_magic_t magic)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 */
drm_getmagic(struct drm_device * dev,void * data,struct drm_file * file_priv)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 */
drm_authmagic(struct drm_device * dev,void * data,struct drm_file * file_priv)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
drm_magic_init(void * arg)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
drm_magic_fini(void * arg)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