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(struct timer_list *t);
  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         timer_setup(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
  59                     0);
  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(struct timer_list *t)
 120 {
 121         struct lib80211_crypt_info *info = from_timer(info, t,
 122                                                       crypt_deinit_timer);
 123         unsigned long flags;
 124
 125         lib80211_crypt_deinit_entries(info, 0);
 126
 127         spin_lock_irqsave(info->lock, flags);
 128         if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
 129                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
 130                        "deletion list\n", info->name);
 131                 info->crypt_deinit_timer.expires = jiffies + HZ;
 132                 add_timer(&info->crypt_deinit_timer);
 133         }
 134         spin_unlock_irqrestore(info->lock, flags);
 135 }
 136
 137 void lib80211_crypt_delayed_deinit(struct lib80211_crypt_info *info,
 138                                     struct lib80211_crypt_data **crypt)
 139 {
 140         struct lib80211_crypt_data *tmp;
 141         unsigned long flags;
 142
 143         if (*crypt == NULL)
 144                 return;
 145
 146         tmp = *crypt;
 147         *crypt = NULL;
 148
 149         /* must not run ops->deinit() while there may be pending encrypt or
 150          * decrypt operations. Use a list of delayed deinits to avoid needing
 151          * locking. */
 152
 153         spin_lock_irqsave(info->lock, flags);
 154         if (!info->crypt_quiesced) {
 155                 list_add(&tmp->list, &info->crypt_deinit_list);
 156                 if (!timer_pending(&info->crypt_deinit_timer)) {
 157                         info->crypt_deinit_timer.expires = jiffies + HZ;
 158                         add_timer(&info->crypt_deinit_timer);
 159                 }
 160         }
 161         spin_unlock_irqrestore(info->lock, flags);
 162 }
 163 EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
 164
 165 int lib80211_register_crypto_ops(struct lib80211_crypto_ops *ops)
 166 {
 167         unsigned long flags;
 168         struct lib80211_crypto_alg *alg;
 169
 170         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 171         if (alg == NULL)
 172                 return -ENOMEM;
 173
 174         alg->ops = ops;
 175
 176         spin_lock_irqsave(&lib80211_crypto_lock, flags);
 177         list_add(&alg->list, &lib80211_crypto_algs);
 178         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 179
 180         printk(KERN_DEBUG "lib80211_crypt: registered algorithm '%s'\n",
 181                ops->name);
 182
 183         return 0;
 184 }
 185 EXPORT_SYMBOL(lib80211_register_crypto_ops);
 186
 187 int lib80211_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
 188 {
 189         struct lib80211_crypto_alg *alg;
 190         unsigned long flags;
 191
 192         spin_lock_irqsave(&lib80211_crypto_lock, flags);
 193         list_for_each_entry(alg, &lib80211_crypto_algs, list) {
 194                 if (alg->ops == ops)
 195                         goto found;
 196         }
 197         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 198         return -EINVAL;
 199
 200       found:
 201         printk(KERN_DEBUG "lib80211_crypt: unregistered algorithm '%s'\n",
 202                ops->name);
 203         list_del(&alg->list);
 204         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 205         kfree(alg);
 206         return 0;
 207 }
 208 EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
 209
 210 struct lib80211_crypto_ops *lib80211_get_crypto_ops(const char *name)
 211 {
 212         struct lib80211_crypto_alg *alg;
 213         unsigned long flags;
 214
 215         spin_lock_irqsave(&lib80211_crypto_lock, flags);
 216         list_for_each_entry(alg, &lib80211_crypto_algs, list) {
 217                 if (strcmp(alg->ops->name, name) == 0)
 218                         goto found;
 219         }
 220         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 221         return NULL;
 222
 223       found:
 224         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 225         return alg->ops;
 226 }
 227 EXPORT_SYMBOL(lib80211_get_crypto_ops);
 228
 229 static void *lib80211_crypt_null_init(int keyidx)
 230 {
 231         return (void *)1;
 232 }
 233
 234 static void lib80211_crypt_null_deinit(void *priv)
 235 {
 236 }
 237
 238 static struct lib80211_crypto_ops lib80211_crypt_null = {
 239         .name = "NULL",
 240         .init = lib80211_crypt_null_init,
 241         .deinit = lib80211_crypt_null_deinit,
 242         .owner = THIS_MODULE,
 243 };
 244
 245 static int __init lib80211_init(void)
 246 {
 247         pr_info(DRV_DESCRIPTION "\n");
 248         return lib80211_register_crypto_ops(&lib80211_crypt_null);
 249 }
 250
 251 static void __exit lib80211_exit(void)
 252 {
 253         lib80211_unregister_crypto_ops(&lib80211_crypt_null);
 254         BUG_ON(!list_empty(&lib80211_crypto_algs));
 255 }
 256
 257 module_init(lib80211_init);
 258 module_exit(lib80211_exit);