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
  45         for (ptr = ieee->crypt_deinit_list.next, n = ptr->next;
  46              ptr != &ieee->crypt_deinit_list; ptr = n, n = ptr->next) {
  47                 entry = list_entry(ptr, struct ieee80211_crypt_data, list);
  48
  49                 if (atomic_read(&entry->refcnt) != 0 && !force)
  50                         continue;
  51
  52                 list_del(ptr);
  53
  54                 if (entry->ops) {
  55                         entry->ops->deinit(entry->priv);
  56                         module_put(entry->ops->owner);
  57                 }
  58                 kfree(entry);
  59         }
  60 }
  61
  62 void ieee80211_crypt_deinit_handler(unsigned long data)
  63 {
  64         struct ieee80211_device *ieee = (struct ieee80211_device *)data;
  65         unsigned long flags;
  66
  67         spin_lock_irqsave(&ieee->lock, flags);
  68         ieee80211_crypt_deinit_entries(ieee, 0);
  69         if (!list_empty(&ieee->crypt_deinit_list)) {
  70                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
  71                        "deletion list\n", ieee->dev->name);
  72                 ieee->crypt_deinit_timer.expires = jiffies + HZ;
  73                 add_timer(&ieee->crypt_deinit_timer);
  74         }
  75         spin_unlock_irqrestore(&ieee->lock, flags);
  76
  77 }
  78
  79 void ieee80211_crypt_delayed_deinit(struct ieee80211_device *ieee,
  80                                     struct ieee80211_crypt_data **crypt)
  81 {
  82         struct ieee80211_crypt_data *tmp;
  83         unsigned long flags;
  84
  85         if (*crypt == NULL)
  86                 return;
  87
  88         tmp = *crypt;
  89         *crypt = NULL;
  90
  91         /* must not run ops->deinit() while there may be pending encrypt or
  92          * decrypt operations. Use a list of delayed deinits to avoid needing
  93          * locking. */
  94
  95         spin_lock_irqsave(&ieee->lock, flags);
  96         list_add(&tmp->list, &ieee->crypt_deinit_list);
  97         if (!timer_pending(&ieee->crypt_deinit_timer)) {
  98                 ieee->crypt_deinit_timer.expires = jiffies + HZ;
  99                 add_timer(&ieee->crypt_deinit_timer);
 100         }
 101         spin_unlock_irqrestore(&ieee->lock, flags);
 102 }
 103
 104 int ieee80211_register_crypto_ops(struct ieee80211_crypto_ops *ops)
 105 {
 106         unsigned long flags;
 107         struct ieee80211_crypto_alg *alg;
 108
 109         if (hcrypt == NULL)
 110                 return -1;
 111
 112         alg = kmalloc(sizeof(*alg), GFP_KERNEL);
 113         if (alg == NULL)
 114                 return -ENOMEM;
 115
 116         memset(alg, 0, sizeof(*alg));
 117         alg->ops = ops;
 118
 119         spin_lock_irqsave(&hcrypt->lock, flags);
 120         list_add(&alg->list, &hcrypt->algs);
 121         spin_unlock_irqrestore(&hcrypt->lock, flags);
 122
 123         printk(KERN_DEBUG "ieee80211_crypt: registered algorithm '%s'\n",
 124                ops->name);
 125
 126         return 0;
 127 }
 128
 129 int ieee80211_unregister_crypto_ops(struct ieee80211_crypto_ops *ops)
 130 {
 131         unsigned long flags;
 132         struct list_head *ptr;
 133         struct ieee80211_crypto_alg *del_alg = NULL;
 134
 135         if (hcrypt == NULL)
 136                 return -1;
 137
 138         spin_lock_irqsave(&hcrypt->lock, flags);
 139         for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
 140                 struct ieee80211_crypto_alg *alg =
 141                     (struct ieee80211_crypto_alg *)ptr;
 142                 if (alg->ops == ops) {
 143                         list_del(&alg->list);
 144                         del_alg = alg;
 145                         break;
 146                 }
 147         }
 148         spin_unlock_irqrestore(&hcrypt->lock, flags);
 149
 150         if (del_alg) {
 151                 printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
 152                        "'%s'\n", ops->name);
 153                 kfree(del_alg);
 154         }
 155
 156         return del_alg ? 0 : -1;
 157 }
 158
 159 struct ieee80211_crypto_ops *ieee80211_get_crypto_ops(const char *name)
 160 {
 161         unsigned long flags;
 162         struct list_head *ptr;
 163         struct ieee80211_crypto_alg *found_alg = NULL;
 164
 165         if (hcrypt == NULL)
 166                 return NULL;
 167
 168         spin_lock_irqsave(&hcrypt->lock, flags);
 169         for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
 170                 struct ieee80211_crypto_alg *alg =
 171                     (struct ieee80211_crypto_alg *)ptr;
 172                 if (strcmp(alg->ops->name, name) == 0) {
 173                         found_alg = alg;
 174                         break;
 175                 }
 176         }
 177         spin_unlock_irqrestore(&hcrypt->lock, flags);
 178
 179         if (found_alg)
 180                 return found_alg->ops;
 181         else
 182                 return NULL;
 183 }
 184
 185 static void *ieee80211_crypt_null_init(int keyidx)
 186 {
 187         return (void *)1;
 188 }
 189 static void ieee80211_crypt_null_deinit(void *priv)
 190 {
 191 }
 192
 193 static struct ieee80211_crypto_ops ieee80211_crypt_null = {
 194         .name                   = "NULL",
 195         .init                   = ieee80211_crypt_null_init,
 196         .deinit                 = ieee80211_crypt_null_deinit,
 197         .encrypt_mpdu           = NULL,
 198         .decrypt_mpdu           = NULL,
 199         .encrypt_msdu           = NULL,
 200         .decrypt_msdu           = NULL,
 201         .set_key                = NULL,
 202         .get_key                = NULL,
 203         .extra_prefix_len       = 0,
 204         .extra_postfix_len      = 0,
 205         .owner                  = THIS_MODULE,
 206 };
 207
 208 static int __init ieee80211_crypto_init(void)
 209 {
 210         int ret = -ENOMEM;
 211
 212         hcrypt = kmalloc(sizeof(*hcrypt), GFP_KERNEL);
 213         if (!hcrypt)
 214                 goto out;
 215
 216         memset(hcrypt, 0, sizeof(*hcrypt));
 217         INIT_LIST_HEAD(&hcrypt->algs);
 218         spin_lock_init(&hcrypt->lock);
 219
 220         ret = ieee80211_register_crypto_ops(&ieee80211_crypt_null);
 221         if (ret < 0) {
 222                 kfree(hcrypt);
 223                 hcrypt = NULL;
 224         }
 225       out:
 226         return ret;
 227 }
 228
 229 static void __exit ieee80211_crypto_deinit(void)
 230 {
 231         struct list_head *ptr, *n;
 232
 233         if (hcrypt == NULL)
 234                 return;
 235
 236         for (ptr = hcrypt->algs.next, n = ptr->next; ptr != &hcrypt->algs;
 237              ptr = n, n = ptr->next) {
 238                 struct ieee80211_crypto_alg *alg =
 239                     (struct ieee80211_crypto_alg *)ptr;
 240                 list_del(ptr);
 241                 printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
 242                        "'%s' (deinit)\n", alg->ops->name);
 243                 kfree(alg);
 244         }
 245
 246         kfree(hcrypt);
 247 }
 248
 249 EXPORT_SYMBOL(ieee80211_crypt_deinit_entries);
 250 EXPORT_SYMBOL(ieee80211_crypt_deinit_handler);
 251 EXPORT_SYMBOL(ieee80211_crypt_delayed_deinit);
 252
 253 EXPORT_SYMBOL(ieee80211_register_crypto_ops);
 254 EXPORT_SYMBOL(ieee80211_unregister_crypto_ops);
 255 EXPORT_SYMBOL(ieee80211_get_crypto_ops);
 256
 257 module_init(ieee80211_crypto_init);
 258 module_exit(ieee80211_crypto_deinit);