GNU Linux-libre 4.14.266-gnu1
[releases.git] / net / wireless / lib80211.c
1 /*
2  * lib80211 -- common bits for IEEE802.11 drivers
3  *
4  * Copyright(c) 2008 John W. Linville <linville@tuxdriver.com>
5  *
6  * Portions copied from old ieee80211 component, w/ original copyright
7  * notices below:
8  *
9  * Host AP crypto routines
10  *
11  * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
12  * Portions Copyright (C) 2004, Intel Corporation <jketreno@linux.intel.com>
13  *
14  */
15
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18 #include <linux/module.h>
19 #include <linux/ctype.h>
20 #include <linux/ieee80211.h>
21 #include <linux/errno.h>
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/string.h>
25
26 #include <net/lib80211.h>
27
28 #define DRV_NAME        "lib80211"
29
30 #define DRV_DESCRIPTION "common routines for IEEE802.11 drivers"
31
32 MODULE_DESCRIPTION(DRV_DESCRIPTION);
33 MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
34 MODULE_LICENSE("GPL");
35
36 struct lib80211_crypto_alg {
37         struct list_head list;
38         struct lib80211_crypto_ops *ops;
39 };
40
41 static LIST_HEAD(lib80211_crypto_algs);
42 static DEFINE_SPINLOCK(lib80211_crypto_lock);
43
44 static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
45                                           int force);
46 static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info);
47 static void lib80211_crypt_deinit_handler(unsigned long data);
48
49 int lib80211_crypt_info_init(struct lib80211_crypt_info *info, char *name,
50                                 spinlock_t *lock)
51 {
52         memset(info, 0, sizeof(*info));
53
54         info->name = name;
55         info->lock = lock;
56
57         INIT_LIST_HEAD(&info->crypt_deinit_list);
58         setup_timer(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
59                         (unsigned long)info);
60
61         return 0;
62 }
63 EXPORT_SYMBOL(lib80211_crypt_info_init);
64
65 void lib80211_crypt_info_free(struct lib80211_crypt_info *info)
66 {
67         int i;
68
69         lib80211_crypt_quiescing(info);
70         del_timer_sync(&info->crypt_deinit_timer);
71         lib80211_crypt_deinit_entries(info, 1);
72
73         for (i = 0; i < NUM_WEP_KEYS; i++) {
74                 struct lib80211_crypt_data *crypt = info->crypt[i];
75                 if (crypt) {
76                         if (crypt->ops) {
77                                 crypt->ops->deinit(crypt->priv);
78                                 module_put(crypt->ops->owner);
79                         }
80                         kfree(crypt);
81                         info->crypt[i] = NULL;
82                 }
83         }
84 }
85 EXPORT_SYMBOL(lib80211_crypt_info_free);
86
87 static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
88                                           int force)
89 {
90         struct lib80211_crypt_data *entry, *next;
91         unsigned long flags;
92
93         spin_lock_irqsave(info->lock, flags);
94         list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
95                 if (atomic_read(&entry->refcnt) != 0 && !force)
96                         continue;
97
98                 list_del(&entry->list);
99
100                 if (entry->ops) {
101                         entry->ops->deinit(entry->priv);
102                         module_put(entry->ops->owner);
103                 }
104                 kfree(entry);
105         }
106         spin_unlock_irqrestore(info->lock, flags);
107 }
108
109 /* After this, crypt_deinit_list won't accept new members */
110 static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info)
111 {
112         unsigned long flags;
113
114         spin_lock_irqsave(info->lock, flags);
115         info->crypt_quiesced = 1;
116         spin_unlock_irqrestore(info->lock, flags);
117 }
118
119 static void lib80211_crypt_deinit_handler(unsigned long data)
120 {
121         struct lib80211_crypt_info *info = (struct lib80211_crypt_info *)data;
122         unsigned long flags;
123
124         lib80211_crypt_deinit_entries(info, 0);
125
126         spin_lock_irqsave(info->lock, flags);
127         if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
128                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
129                        "deletion list\n", info->name);
130                 info->crypt_deinit_timer.expires = jiffies + HZ;
131                 add_timer(&info->crypt_deinit_timer);
132         }
133         spin_unlock_irqrestore(info->lock, flags);
134 }
135
136 void lib80211_crypt_delayed_deinit(struct lib80211_crypt_info *info,
137                                     struct lib80211_crypt_data **crypt)
138 {
139         struct lib80211_crypt_data *tmp;
140         unsigned long flags;
141
142         if (*crypt == NULL)
143                 return;
144
145         tmp = *crypt;
146         *crypt = NULL;
147
148         /* must not run ops->deinit() while there may be pending encrypt or
149          * decrypt operations. Use a list of delayed deinits to avoid needing
150          * locking. */
151
152         spin_lock_irqsave(info->lock, flags);
153         if (!info->crypt_quiesced) {
154                 list_add(&tmp->list, &info->crypt_deinit_list);
155                 if (!timer_pending(&info->crypt_deinit_timer)) {
156                         info->crypt_deinit_timer.expires = jiffies + HZ;
157                         add_timer(&info->crypt_deinit_timer);
158                 }
159         }
160         spin_unlock_irqrestore(info->lock, flags);
161 }
162 EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
163
164 int lib80211_register_crypto_ops(struct lib80211_crypto_ops *ops)
165 {
166         unsigned long flags;
167         struct lib80211_crypto_alg *alg;
168
169         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
170         if (alg == NULL)
171                 return -ENOMEM;
172
173         alg->ops = ops;
174
175         spin_lock_irqsave(&lib80211_crypto_lock, flags);
176         list_add(&alg->list, &lib80211_crypto_algs);
177         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
178
179         printk(KERN_DEBUG "lib80211_crypt: registered algorithm '%s'\n",
180                ops->name);
181
182         return 0;
183 }
184 EXPORT_SYMBOL(lib80211_register_crypto_ops);
185
186 int lib80211_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
187 {
188         struct lib80211_crypto_alg *alg;
189         unsigned long flags;
190
191         spin_lock_irqsave(&lib80211_crypto_lock, flags);
192         list_for_each_entry(alg, &lib80211_crypto_algs, list) {
193                 if (alg->ops == ops)
194                         goto found;
195         }
196         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
197         return -EINVAL;
198
199       found:
200         printk(KERN_DEBUG "lib80211_crypt: unregistered algorithm '%s'\n",
201                ops->name);
202         list_del(&alg->list);
203         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
204         kfree(alg);
205         return 0;
206 }
207 EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
208
209 struct lib80211_crypto_ops *lib80211_get_crypto_ops(const char *name)
210 {
211         struct lib80211_crypto_alg *alg;
212         unsigned long flags;
213
214         spin_lock_irqsave(&lib80211_crypto_lock, flags);
215         list_for_each_entry(alg, &lib80211_crypto_algs, list) {
216                 if (strcmp(alg->ops->name, name) == 0)
217                         goto found;
218         }
219         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
220         return NULL;
221
222       found:
223         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
224         return alg->ops;
225 }
226 EXPORT_SYMBOL(lib80211_get_crypto_ops);
227
228 static void *lib80211_crypt_null_init(int keyidx)
229 {
230         return (void *)1;
231 }
232
233 static void lib80211_crypt_null_deinit(void *priv)
234 {
235 }
236
237 static struct lib80211_crypto_ops lib80211_crypt_null = {
238         .name = "NULL",
239         .init = lib80211_crypt_null_init,
240         .deinit = lib80211_crypt_null_deinit,
241         .owner = THIS_MODULE,
242 };
243
244 static int __init lib80211_init(void)
245 {
246         pr_info(DRV_DESCRIPTION "\n");
247         return lib80211_register_crypto_ops(&lib80211_crypt_null);
248 }
249
250 static void __exit lib80211_exit(void)
251 {
252         lib80211_unregister_crypto_ops(&lib80211_crypt_null);
253         BUG_ON(!list_empty(&lib80211_crypto_algs));
254 }
255
256 module_init(lib80211_init);
257 module_exit(lib80211_exit);