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 const char *print_ssid(char *buf, const char *ssid, u8 ssid_len)
  50 {
  51         const char *s = ssid;
  52         char *d = buf;
  53
  54         ssid_len = min_t(u8, ssid_len, IEEE80211_MAX_SSID_LEN);
  55         while (ssid_len--) {
  56                 if (isprint(*s)) {
  57                         *d++ = *s++;
  58                         continue;
  59                 }
  60
  61                 *d++ = '\\';
  62                 if (*s == '\0')
  63                         *d++ = '0';
  64                 else if (*s == '\n')
  65                         *d++ = 'n';
  66                 else if (*s == '\r')
  67                         *d++ = 'r';
  68                 else if (*s == '\t')
  69                         *d++ = 't';
  70                 else if (*s == '\\')
  71                         *d++ = '\\';
  72                 else
  73                         d += snprintf(d, 3, "%03o", *s);
  74                 s++;
  75         }
  76         *d = '\0';
  77         return buf;
  78 }
  79 EXPORT_SYMBOL(print_ssid);
  80
  81 int lib80211_crypt_info_init(struct lib80211_crypt_info *info, char *name,
  82                                 spinlock_t *lock)
  83 {
  84         memset(info, 0, sizeof(*info));
  85
  86         info->name = name;
  87         info->lock = lock;
  88
  89         INIT_LIST_HEAD(&info->crypt_deinit_list);
  90         setup_timer(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
  91                         (unsigned long)info);
  92
  93         return 0;
  94 }
  95 EXPORT_SYMBOL(lib80211_crypt_info_init);
  96
  97 void lib80211_crypt_info_free(struct lib80211_crypt_info *info)
  98 {
  99         int i;
 100
 101         lib80211_crypt_quiescing(info);
 102         del_timer_sync(&info->crypt_deinit_timer);
 103         lib80211_crypt_deinit_entries(info, 1);
 104
 105         for (i = 0; i < NUM_WEP_KEYS; i++) {
 106                 struct lib80211_crypt_data *crypt = info->crypt[i];
 107                 if (crypt) {
 108                         if (crypt->ops) {
 109                                 crypt->ops->deinit(crypt->priv);
 110                                 module_put(crypt->ops->owner);
 111                         }
 112                         kfree(crypt);
 113                         info->crypt[i] = NULL;
 114                 }
 115         }
 116 }
 117 EXPORT_SYMBOL(lib80211_crypt_info_free);
 118
 119 static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
 120                                           int force)
 121 {
 122         struct lib80211_crypt_data *entry, *next;
 123         unsigned long flags;
 124
 125         spin_lock_irqsave(info->lock, flags);
 126         list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
 127                 if (atomic_read(&entry->refcnt) != 0 && !force)
 128                         continue;
 129
 130                 list_del(&entry->list);
 131
 132                 if (entry->ops) {
 133                         entry->ops->deinit(entry->priv);
 134                         module_put(entry->ops->owner);
 135                 }
 136                 kfree(entry);
 137         }
 138         spin_unlock_irqrestore(info->lock, flags);
 139 }
 140
 141 /* After this, crypt_deinit_list won't accept new members */
 142 static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info)
 143 {
 144         unsigned long flags;
 145
 146         spin_lock_irqsave(info->lock, flags);
 147         info->crypt_quiesced = 1;
 148         spin_unlock_irqrestore(info->lock, flags);
 149 }
 150
 151 static void lib80211_crypt_deinit_handler(unsigned long data)
 152 {
 153         struct lib80211_crypt_info *info = (struct lib80211_crypt_info *)data;
 154         unsigned long flags;
 155
 156         lib80211_crypt_deinit_entries(info, 0);
 157
 158         spin_lock_irqsave(info->lock, flags);
 159         if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
 160                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
 161                        "deletion list\n", info->name);
 162                 info->crypt_deinit_timer.expires = jiffies + HZ;
 163                 add_timer(&info->crypt_deinit_timer);
 164         }
 165         spin_unlock_irqrestore(info->lock, flags);
 166 }
 167
 168 void lib80211_crypt_delayed_deinit(struct lib80211_crypt_info *info,
 169                                     struct lib80211_crypt_data **crypt)
 170 {
 171         struct lib80211_crypt_data *tmp;
 172         unsigned long flags;
 173
 174         if (*crypt == NULL)
 175                 return;
 176
 177         tmp = *crypt;
 178         *crypt = NULL;
 179
 180         /* must not run ops->deinit() while there may be pending encrypt or
 181          * decrypt operations. Use a list of delayed deinits to avoid needing
 182          * locking. */
 183
 184         spin_lock_irqsave(info->lock, flags);
 185         if (!info->crypt_quiesced) {
 186                 list_add(&tmp->list, &info->crypt_deinit_list);
 187                 if (!timer_pending(&info->crypt_deinit_timer)) {
 188                         info->crypt_deinit_timer.expires = jiffies + HZ;
 189                         add_timer(&info->crypt_deinit_timer);
 190                 }
 191         }
 192         spin_unlock_irqrestore(info->lock, flags);
 193 }
 194 EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
 195
 196 int lib80211_register_crypto_ops(struct lib80211_crypto_ops *ops)
 197 {
 198         unsigned long flags;
 199         struct lib80211_crypto_alg *alg;
 200
 201         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 202         if (alg == NULL)
 203                 return -ENOMEM;
 204
 205         alg->ops = ops;
 206
 207         spin_lock_irqsave(&lib80211_crypto_lock, flags);
 208         list_add(&alg->list, &lib80211_crypto_algs);
 209         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 210
 211         printk(KERN_DEBUG "lib80211_crypt: registered algorithm '%s'\n",
 212                ops->name);
 213
 214         return 0;
 215 }
 216 EXPORT_SYMBOL(lib80211_register_crypto_ops);
 217
 218 int lib80211_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
 219 {
 220         struct lib80211_crypto_alg *alg;
 221         unsigned long flags;
 222
 223         spin_lock_irqsave(&lib80211_crypto_lock, flags);
 224         list_for_each_entry(alg, &lib80211_crypto_algs, list) {
 225                 if (alg->ops == ops)
 226                         goto found;
 227         }
 228         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 229         return -EINVAL;
 230
 231       found:
 232         printk(KERN_DEBUG "lib80211_crypt: unregistered algorithm '%s'\n",
 233                ops->name);
 234         list_del(&alg->list);
 235         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 236         kfree(alg);
 237         return 0;
 238 }
 239 EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
 240
 241 struct lib80211_crypto_ops *lib80211_get_crypto_ops(const char *name)
 242 {
 243         struct lib80211_crypto_alg *alg;
 244         unsigned long flags;
 245
 246         spin_lock_irqsave(&lib80211_crypto_lock, flags);
 247         list_for_each_entry(alg, &lib80211_crypto_algs, list) {
 248                 if (strcmp(alg->ops->name, name) == 0)
 249                         goto found;
 250         }
 251         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 252         return NULL;
 253
 254       found:
 255         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 256         return alg->ops;
 257 }
 258 EXPORT_SYMBOL(lib80211_get_crypto_ops);
 259
 260 static void *lib80211_crypt_null_init(int keyidx)
 261 {
 262         return (void *)1;
 263 }
 264
 265 static void lib80211_crypt_null_deinit(void *priv)
 266 {
 267 }
 268
 269 static struct lib80211_crypto_ops lib80211_crypt_null = {
 270         .name = "NULL",
 271         .init = lib80211_crypt_null_init,
 272         .deinit = lib80211_crypt_null_deinit,
 273         .owner = THIS_MODULE,
 274 };
 275
 276 static int __init lib80211_init(void)
 277 {
 278         pr_info(DRV_DESCRIPTION "\n");
 279         return lib80211_register_crypto_ops(&lib80211_crypt_null);
 280 }
 281
 282 static void __exit lib80211_exit(void)
 283 {
 284         lib80211_unregister_crypto_ops(&lib80211_crypt_null);
 285         BUG_ON(!list_empty(&lib80211_crypto_algs));
 286 }
 287
 288 module_init(lib80211_init);
 289 module_exit(lib80211_exit);