net/ieee80211/ieee80211_crypt.c

   1 /*
   2  * Host AP crypto routines
   3  *
   4  * Copyright (c) 2002-2003, Jouni Malinen <jkmaline@cc.hut.fi>
   5  * Portions Copyright (C) 2004, Intel Corporation <jketreno@linux.intel.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation. See README and COPYING for
  10  * more details.
  11  *
  12  */
  13
  14 #include <linux/config.h>
  15 #include <linux/version.h>
  16 #include <linux/module.h>
  17 #include <linux/init.h>
  18 #include <linux/slab.h>
  19 #include <asm/string.h>
  20 #include <asm/errno.h>
  21
  22 #include <net/ieee80211.h>
  23
  24 MODULE_AUTHOR("Jouni Malinen");
  25 MODULE_DESCRIPTION("HostAP crypto");
  26 MODULE_LICENSE("GPL");
  27
  28 struct ieee80211_crypto_alg {
  29         struct list_head list;
  30         struct ieee80211_crypto_ops *ops;
  31 };
  32
  33 struct ieee80211_crypto {
  34         struct list_head algs;
  35         spinlock_t lock;
  36 };
  37
  38 static struct ieee80211_crypto *hcrypt;
  39
  40 void ieee80211_crypt_deinit_entries(struct ieee80211_device *ieee, int force)
  41 {
  42         struct list_head *ptr, *n;
  43         struct ieee80211_crypt_data *entry;
  44         unsigned long flags;
  45
  46         spin_lock_irqsave(&ieee->lock, flags);
  47
  48         if (list_empty(&ieee->crypt_deinit_list))
  49                 goto unlock;
  50
  51         for (ptr = ieee->crypt_deinit_list.next, n = ptr->next;
  52              ptr != &ieee->crypt_deinit_list; ptr = n, n = ptr->next) {
  53                 entry = list_entry(ptr, struct ieee80211_crypt_data, list);
  54
  55                 if (atomic_read(&entry->refcnt) != 0 && !force)
  56                         continue;
  57
  58                 list_del(ptr);
  59
  60                 if (entry->ops) {
  61                         entry->ops->deinit(entry->priv);
  62                         module_put(entry->ops->owner);
  63                 }
  64                 kfree(entry);
  65         }
  66       unlock:
  67         spin_unlock_irqrestore(&ieee->lock, flags);
  68 }
  69
  70 /* After this, crypt_deinit_list won't accept new members */
  71 void ieee80211_crypt_quiescing(struct ieee80211_device *ieee)
  72 {
  73         unsigned long flags;
  74
  75         spin_lock_irqsave(&ieee->lock, flags);
  76         ieee->crypt_quiesced = 1;
  77         spin_unlock_irqrestore(&ieee->lock, flags);
  78 }
  79
  80 void ieee80211_crypt_deinit_handler(unsigned long data)
  81 {
  82         struct ieee80211_device *ieee = (struct ieee80211_device *)data;
  83         unsigned long flags;
  84
  85         ieee80211_crypt_deinit_entries(ieee, 0);
  86
  87         spin_lock_irqsave(&ieee->lock, flags);
  88         if (!list_empty(&ieee->crypt_deinit_list) && !ieee->crypt_quiesced) {
  89                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
  90                        "deletion list\n", ieee->dev->name);
  91                 ieee->crypt_deinit_timer.expires = jiffies + HZ;
  92                 add_timer(&ieee->crypt_deinit_timer);
  93         }
  94         spin_unlock_irqrestore(&ieee->lock, flags);
  95 }
  96
  97 void ieee80211_crypt_delayed_deinit(struct ieee80211_device *ieee,
  98                                     struct ieee80211_crypt_data **crypt)
  99 {
 100         struct ieee80211_crypt_data *tmp;
 101         unsigned long flags;
 102
 103         if (*crypt == NULL)
 104                 return;
 105
 106         tmp = *crypt;
 107         *crypt = NULL;
 108
 109         /* must not run ops->deinit() while there may be pending encrypt or
 110          * decrypt operations. Use a list of delayed deinits to avoid needing
 111          * locking. */
 112
 113         spin_lock_irqsave(&ieee->lock, flags);
 114         if (!ieee->crypt_quiesced) {
 115                 list_add(&tmp->list, &ieee->crypt_deinit_list);
 116                 if (!timer_pending(&ieee->crypt_deinit_timer)) {
 117                         ieee->crypt_deinit_timer.expires = jiffies + HZ;
 118                         add_timer(&ieee->crypt_deinit_timer);
 119                 }
 120         }
 121         spin_unlock_irqrestore(&ieee->lock, flags);
 122 }
 123
 124 int ieee80211_register_crypto_ops(struct ieee80211_crypto_ops *ops)
 125 {
 126         unsigned long flags;
 127         struct ieee80211_crypto_alg *alg;
 128
 129         if (hcrypt == NULL)
 130                 return -1;
 131
 132         alg = kmalloc(sizeof(*alg), GFP_KERNEL);
 133         if (alg == NULL)
 134                 return -ENOMEM;
 135
 136         memset(alg, 0, sizeof(*alg));
 137         alg->ops = ops;
 138
 139         spin_lock_irqsave(&hcrypt->lock, flags);
 140         list_add(&alg->list, &hcrypt->algs);
 141         spin_unlock_irqrestore(&hcrypt->lock, flags);
 142
 143         printk(KERN_DEBUG "ieee80211_crypt: registered algorithm '%s'\n",
 144                ops->name);
 145
 146         return 0;
 147 }
 148
 149 int ieee80211_unregister_crypto_ops(struct ieee80211_crypto_ops *ops)
 150 {
 151         unsigned long flags;
 152         struct list_head *ptr;
 153         struct ieee80211_crypto_alg *del_alg = NULL;
 154
 155         if (hcrypt == NULL)
 156                 return -1;
 157
 158         spin_lock_irqsave(&hcrypt->lock, flags);
 159         for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
 160                 struct ieee80211_crypto_alg *alg =
 161                     (struct ieee80211_crypto_alg *)ptr;
 162                 if (alg->ops == ops) {
 163                         list_del(&alg->list);
 164                         del_alg = alg;
 165                         break;
 166                 }
 167         }
 168         spin_unlock_irqrestore(&hcrypt->lock, flags);
 169
 170         if (del_alg) {
 171                 printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
 172                        "'%s'\n", ops->name);
 173                 kfree(del_alg);
 174         }
 175
 176         return del_alg ? 0 : -1;
 177 }
 178
 179 struct ieee80211_crypto_ops *ieee80211_get_crypto_ops(const char *name)
 180 {
 181         unsigned long flags;
 182         struct list_head *ptr;
 183         struct ieee80211_crypto_alg *found_alg = NULL;
 184
 185         if (hcrypt == NULL)
 186                 return NULL;
 187
 188         spin_lock_irqsave(&hcrypt->lock, flags);
 189         for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
 190                 struct ieee80211_crypto_alg *alg =
 191                     (struct ieee80211_crypto_alg *)ptr;
 192                 if (strcmp(alg->ops->name, name) == 0) {
 193                         found_alg = alg;
 194                         break;
 195                 }
 196         }
 197         spin_unlock_irqrestore(&hcrypt->lock, flags);
 198
 199         if (found_alg)
 200                 return found_alg->ops;
 201         else
 202                 return NULL;
 203 }
 204
 205 static void *ieee80211_crypt_null_init(int keyidx)
 206 {
 207         return (void *)1;
 208 }
 209 static void ieee80211_crypt_null_deinit(void *priv)
 210 {
 211 }
 212
 213 static struct ieee80211_crypto_ops ieee80211_crypt_null = {
 214         .name = "NULL",
 215         .init = ieee80211_crypt_null_init,
 216         .deinit = ieee80211_crypt_null_deinit,
 217         .encrypt_mpdu = NULL,
 218         .decrypt_mpdu = NULL,
 219         .encrypt_msdu = NULL,
 220         .decrypt_msdu = NULL,
 221         .set_key = NULL,
 222         .get_key = NULL,
 223         .extra_mpdu_prefix_len = 0,
 224         .extra_mpdu_postfix_len = 0,
 225         .owner = THIS_MODULE,
 226 };
 227
 228 static int __init ieee80211_crypto_init(void)
 229 {
 230         int ret = -ENOMEM;
 231
 232         hcrypt = kmalloc(sizeof(*hcrypt), GFP_KERNEL);
 233         if (!hcrypt)
 234                 goto out;
 235
 236         memset(hcrypt, 0, sizeof(*hcrypt));
 237         INIT_LIST_HEAD(&hcrypt->algs);
 238         spin_lock_init(&hcrypt->lock);
 239
 240         ret = ieee80211_register_crypto_ops(&ieee80211_crypt_null);
 241         if (ret < 0) {
 242                 kfree(hcrypt);
 243                 hcrypt = NULL;
 244         }
 245       out:
 246         return ret;
 247 }
 248
 249 static void __exit ieee80211_crypto_deinit(void)
 250 {
 251         struct list_head *ptr, *n;
 252
 253         if (hcrypt == NULL)
 254                 return;
 255
 256         for (ptr = hcrypt->algs.next, n = ptr->next; ptr != &hcrypt->algs;
 257              ptr = n, n = ptr->next) {
 258                 struct ieee80211_crypto_alg *alg =
 259                     (struct ieee80211_crypto_alg *)ptr;
 260                 list_del(ptr);
 261                 printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
 262                        "'%s' (deinit)\n", alg->ops->name);
 263                 kfree(alg);
 264         }
 265
 266         kfree(hcrypt);
 267 }
 268
 269 EXPORT_SYMBOL(ieee80211_crypt_deinit_entries);
 270 EXPORT_SYMBOL(ieee80211_crypt_deinit_handler);
 271 EXPORT_SYMBOL(ieee80211_crypt_delayed_deinit);
 272 EXPORT_SYMBOL(ieee80211_crypt_quiescing);
 273
 274 EXPORT_SYMBOL(ieee80211_register_crypto_ops);
 275 EXPORT_SYMBOL(ieee80211_unregister_crypto_ops);
 276 EXPORT_SYMBOL(ieee80211_get_crypto_ops);
 277
 278 module_init(ieee80211_crypto_init);
 279 module_exit(ieee80211_crypto_deinit);