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/errno.h>
  15 #include <linux/module.h>
  16 #include <linux/init.h>
  17 #include <linux/slab.h>
  18 #include <linux/string.h>
  19 #include <net/ieee80211.h>
  20
  21
  22 MODULE_AUTHOR("Jouni Malinen");
  23 MODULE_DESCRIPTION("HostAP crypto");
  24 MODULE_LICENSE("GPL");
  25
  26 struct ieee80211_crypto_alg {
  27         struct list_head list;
  28         struct ieee80211_crypto_ops *ops;
  29 };
  30
  31 static LIST_HEAD(ieee80211_crypto_algs);
  32 static DEFINE_SPINLOCK(ieee80211_crypto_lock);
  33
  34 void ieee80211_crypt_deinit_entries(struct ieee80211_device *ieee, int force)
  35 {
  36         struct ieee80211_crypt_data *entry, *next;
  37         unsigned long flags;
  38
  39         spin_lock_irqsave(&ieee->lock, flags);
  40         list_for_each_entry_safe(entry, next, &ieee->crypt_deinit_list, list) {
  41                 if (atomic_read(&entry->refcnt) != 0 && !force)
  42                         continue;
  43
  44                 list_del(&entry->list);
  45
  46                 if (entry->ops) {
  47                         entry->ops->deinit(entry->priv);
  48                         module_put(entry->ops->owner);
  49                 }
  50                 kfree(entry);
  51         }
  52         spin_unlock_irqrestore(&ieee->lock, flags);
  53 }
  54
  55 /* After this, crypt_deinit_list won't accept new members */
  56 void ieee80211_crypt_quiescing(struct ieee80211_device *ieee)
  57 {
  58         unsigned long flags;
  59
  60         spin_lock_irqsave(&ieee->lock, flags);
  61         ieee->crypt_quiesced = 1;
  62         spin_unlock_irqrestore(&ieee->lock, flags);
  63 }
  64
  65 void ieee80211_crypt_deinit_handler(unsigned long data)
  66 {
  67         struct ieee80211_device *ieee = (struct ieee80211_device *)data;
  68         unsigned long flags;
  69
  70         ieee80211_crypt_deinit_entries(ieee, 0);
  71
  72         spin_lock_irqsave(&ieee->lock, flags);
  73         if (!list_empty(&ieee->crypt_deinit_list) && !ieee->crypt_quiesced) {
  74                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
  75                        "deletion list\n", ieee->dev->name);
  76                 ieee->crypt_deinit_timer.expires = jiffies + HZ;
  77                 add_timer(&ieee->crypt_deinit_timer);
  78         }
  79         spin_unlock_irqrestore(&ieee->lock, flags);
  80 }
  81
  82 void ieee80211_crypt_delayed_deinit(struct ieee80211_device *ieee,
  83                                     struct ieee80211_crypt_data **crypt)
  84 {
  85         struct ieee80211_crypt_data *tmp;
  86         unsigned long flags;
  87
  88         if (*crypt == NULL)
  89                 return;
  90
  91         tmp = *crypt;
  92         *crypt = NULL;
  93
  94         /* must not run ops->deinit() while there may be pending encrypt or
  95          * decrypt operations. Use a list of delayed deinits to avoid needing
  96          * locking. */
  97
  98         spin_lock_irqsave(&ieee->lock, flags);
  99         if (!ieee->crypt_quiesced) {
 100                 list_add(&tmp->list, &ieee->crypt_deinit_list);
 101                 if (!timer_pending(&ieee->crypt_deinit_timer)) {
 102                         ieee->crypt_deinit_timer.expires = jiffies + HZ;
 103                         add_timer(&ieee->crypt_deinit_timer);
 104                 }
 105         }
 106         spin_unlock_irqrestore(&ieee->lock, flags);
 107 }
 108
 109 int ieee80211_register_crypto_ops(struct ieee80211_crypto_ops *ops)
 110 {
 111         unsigned long flags;
 112         struct ieee80211_crypto_alg *alg;
 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(&ieee80211_crypto_lock, flags);
 122         list_add(&alg->list, &ieee80211_crypto_algs);
 123         spin_unlock_irqrestore(&ieee80211_crypto_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         struct ieee80211_crypto_alg *alg;
 134         unsigned long flags;
 135
 136         spin_lock_irqsave(&ieee80211_crypto_lock, flags);
 137         list_for_each_entry(alg, &ieee80211_crypto_algs, list) {
 138                 if (alg->ops == ops)
 139                         goto found;
 140         }
 141         spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
 142         return -EINVAL;
 143
 144  found:
 145         printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
 146                           "'%s'\n", ops->name);
 147         list_del(&alg->list);
 148         spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
 149         kfree(alg);
 150         return 0;
 151 }
 152
 153 struct ieee80211_crypto_ops *ieee80211_get_crypto_ops(const char *name)
 154 {
 155         struct ieee80211_crypto_alg *alg;
 156         unsigned long flags;
 157
 158         spin_lock_irqsave(&ieee80211_crypto_lock, flags);
 159         list_for_each_entry(alg, &ieee80211_crypto_algs, list) {
 160                 if (strcmp(alg->ops->name, name) == 0)
 161                         goto found;
 162         }
 163         spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
 164         return NULL;
 165
 166  found:
 167         spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
 168         return alg->ops;
 169 }
 170
 171 static void *ieee80211_crypt_null_init(int keyidx)
 172 {
 173         return (void *)1;
 174 }
 175
 176 static void ieee80211_crypt_null_deinit(void *priv)
 177 {
 178 }
 179
 180 static struct ieee80211_crypto_ops ieee80211_crypt_null = {
 181         .name = "NULL",
 182         .init = ieee80211_crypt_null_init,
 183         .deinit = ieee80211_crypt_null_deinit,
 184         .owner = THIS_MODULE,
 185 };
 186
 187 static int __init ieee80211_crypto_init(void)
 188 {
 189         return ieee80211_register_crypto_ops(&ieee80211_crypt_null);
 190 }
 191
 192 static void __exit ieee80211_crypto_deinit(void)
 193 {
 194         ieee80211_unregister_crypto_ops(&ieee80211_crypt_null);
 195         BUG_ON(!list_empty(&ieee80211_crypto_algs));
 196 }
 197
 198 EXPORT_SYMBOL(ieee80211_crypt_deinit_entries);
 199 EXPORT_SYMBOL(ieee80211_crypt_deinit_handler);
 200 EXPORT_SYMBOL(ieee80211_crypt_delayed_deinit);
 201 EXPORT_SYMBOL(ieee80211_crypt_quiescing);
 202
 203 EXPORT_SYMBOL(ieee80211_register_crypto_ops);
 204 EXPORT_SYMBOL(ieee80211_unregister_crypto_ops);
 205 EXPORT_SYMBOL(ieee80211_get_crypto_ops);
 206
 207 module_init(ieee80211_crypto_init);
 208 module_exit(ieee80211_crypto_deinit);