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
  34 struct ieee80211_crypto {
  35         struct list_head algs;
  36         spinlock_t lock;
  37 };
  38
  39 static struct ieee80211_crypto *hcrypt;
  40
  41 void ieee80211_crypt_deinit_entries(struct ieee80211_device *ieee,
  42                                            int force)
  43 {
  44         struct list_head *ptr, *n;
  45         struct ieee80211_crypt_data *entry;
  46
  47         for (ptr = ieee->crypt_deinit_list.next, n = ptr->next;
  48              ptr != &ieee->crypt_deinit_list; ptr = n, n = ptr->next) {
  49                 entry = list_entry(ptr, struct ieee80211_crypt_data, list);
  50
  51                 if (atomic_read(&entry->refcnt) != 0 && !force)
  52                         continue;
  53
  54                 list_del(ptr);
  55
  56                 if (entry->ops) {
  57                         entry->ops->deinit(entry->priv);
  58                         module_put(entry->ops->owner);
  59                 }
  60                 kfree(entry);
  61         }
  62 }
  63
  64 void ieee80211_crypt_deinit_handler(unsigned long data)
  65 {
  66         struct ieee80211_device *ieee = (struct ieee80211_device *)data;
  67         unsigned long flags;
  68
  69         spin_lock_irqsave(&ieee->lock, flags);
  70         ieee80211_crypt_deinit_entries(ieee, 0);
  71         if (!list_empty(&ieee->crypt_deinit_list)) {
  72                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
  73                        "deletion list\n", ieee->dev->name);
  74                 ieee->crypt_deinit_timer.expires = jiffies + HZ;
  75                 add_timer(&ieee->crypt_deinit_timer);
  76         }
  77         spin_unlock_irqrestore(&ieee->lock, flags);
  78
  79 }
  80
  81 void ieee80211_crypt_delayed_deinit(struct ieee80211_device *ieee,
  82                                     struct ieee80211_crypt_data **crypt)
  83 {
  84         struct ieee80211_crypt_data *tmp;
  85         unsigned long flags;
  86
  87         if (*crypt == NULL)
  88                 return;
  89
  90         tmp = *crypt;
  91         *crypt = NULL;
  92
  93         /* must not run ops->deinit() while there may be pending encrypt or
  94          * decrypt operations. Use a list of delayed deinits to avoid needing
  95          * locking. */
  96
  97         spin_lock_irqsave(&ieee->lock, flags);
  98         list_add(&tmp->list, &ieee->crypt_deinit_list);
  99         if (!timer_pending(&ieee->crypt_deinit_timer)) {
 100                 ieee->crypt_deinit_timer.expires = jiffies + HZ;
 101                 add_timer(&ieee->crypt_deinit_timer);
 102         }
 103         spin_unlock_irqrestore(&ieee->lock, flags);
 104 }
 105
 106 int ieee80211_register_crypto_ops(struct ieee80211_crypto_ops *ops)
 107 {
 108         unsigned long flags;
 109         struct ieee80211_crypto_alg *alg;
 110
 111         if (hcrypt == NULL)
 112                 return -1;
 113
 114         alg = kmalloc(sizeof(*alg), GFP_KERNEL);
 115         if (alg == NULL)
 116                 return -ENOMEM;
 117
 118         memset(alg, 0, sizeof(*alg));
 119         alg->ops = ops;
 120
 121         spin_lock_irqsave(&hcrypt->lock, flags);
 122         list_add(&alg->list, &hcrypt->algs);
 123         spin_unlock_irqrestore(&hcrypt->lock, flags);
 124
 125         printk(KERN_DEBUG "ieee80211_crypt: registered algorithm '%s'\n",
 126                ops->name);
 127
 128         return 0;
 129 }
 130
 131 int ieee80211_unregister_crypto_ops(struct ieee80211_crypto_ops *ops)
 132 {
 133         unsigned long flags;
 134         struct list_head *ptr;
 135         struct ieee80211_crypto_alg *del_alg = NULL;
 136
 137         if (hcrypt == NULL)
 138                 return -1;
 139
 140         spin_lock_irqsave(&hcrypt->lock, flags);
 141         for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
 142                 struct ieee80211_crypto_alg *alg =
 143                         (struct ieee80211_crypto_alg *) ptr;
 144                 if (alg->ops == ops) {
 145                         list_del(&alg->list);
 146                         del_alg = alg;
 147                         break;
 148                 }
 149         }
 150         spin_unlock_irqrestore(&hcrypt->lock, flags);
 151
 152         if (del_alg) {
 153                 printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
 154                        "'%s'\n", ops->name);
 155                 kfree(del_alg);
 156         }
 157
 158         return del_alg ? 0 : -1;
 159 }
 160
 161
 162 struct ieee80211_crypto_ops * ieee80211_get_crypto_ops(const char *name)
 163 {
 164         unsigned long flags;
 165         struct list_head *ptr;
 166         struct ieee80211_crypto_alg *found_alg = NULL;
 167
 168         if (hcrypt == NULL)
 169                 return NULL;
 170
 171         spin_lock_irqsave(&hcrypt->lock, flags);
 172         for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
 173                 struct ieee80211_crypto_alg *alg =
 174                         (struct ieee80211_crypto_alg *) ptr;
 175                 if (strcmp(alg->ops->name, name) == 0) {
 176                         found_alg = alg;
 177                         break;
 178                 }
 179         }
 180         spin_unlock_irqrestore(&hcrypt->lock, flags);
 181
 182         if (found_alg)
 183                 return found_alg->ops;
 184         else
 185                 return NULL;
 186 }
 187
 188
 189 static void * ieee80211_crypt_null_init(int keyidx) { return (void *) 1; }
 190 static void ieee80211_crypt_null_deinit(void *priv) {}
 191
 192 static struct ieee80211_crypto_ops ieee80211_crypt_null = {
 193         .name                   = "NULL",
 194         .init                   = ieee80211_crypt_null_init,
 195         .deinit                 = ieee80211_crypt_null_deinit,
 196         .encrypt_mpdu           = NULL,
 197         .decrypt_mpdu           = NULL,
 198         .encrypt_msdu           = NULL,
 199         .decrypt_msdu           = NULL,
 200         .set_key                = NULL,
 201         .get_key                = NULL,
 202         .extra_prefix_len       = 0,
 203         .extra_postfix_len      = 0,
 204         .owner                  = THIS_MODULE,
 205 };
 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
 230 static void __exit ieee80211_crypto_deinit(void)
 231 {
 232         struct list_head *ptr, *n;
 233
 234         if (hcrypt == NULL)
 235                 return;
 236
 237         for (ptr = hcrypt->algs.next, n = ptr->next; ptr != &hcrypt->algs;
 238              ptr = n, n = ptr->next) {
 239                 struct ieee80211_crypto_alg *alg =
 240                         (struct ieee80211_crypto_alg *) ptr;
 241                 list_del(ptr);
 242                 printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
 243                        "'%s' (deinit)\n", alg->ops->name);
 244                 kfree(alg);
 245         }
 246
 247         kfree(hcrypt);
 248 }
 249
 250 EXPORT_SYMBOL(ieee80211_crypt_deinit_entries);
 251 EXPORT_SYMBOL(ieee80211_crypt_deinit_handler);
 252 EXPORT_SYMBOL(ieee80211_crypt_delayed_deinit);
 253
 254 EXPORT_SYMBOL(ieee80211_register_crypto_ops);
 255 EXPORT_SYMBOL(ieee80211_unregister_crypto_ops);
 256 EXPORT_SYMBOL(ieee80211_get_crypto_ops);
 257
 258 module_init(ieee80211_crypto_init);
 259 module_exit(ieee80211_crypto_deinit);