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 MODULE_AUTHOR("Jouni Malinen");
  22 MODULE_DESCRIPTION("HostAP crypto");
  23 MODULE_LICENSE("GPL");
  24
  25 struct ieee80211_crypto_alg {
  26         struct list_head list;
  27         struct ieee80211_crypto_ops *ops;
  28 };
  29
  30 static LIST_HEAD(ieee80211_crypto_algs);
  31 static DEFINE_SPINLOCK(ieee80211_crypto_lock);
  32
  33 void ieee80211_crypt_deinit_entries(struct ieee80211_device *ieee, int force)
  34 {
  35         struct ieee80211_crypt_data *entry, *next;
  36         unsigned long flags;
  37
  38         spin_lock_irqsave(&ieee->lock, flags);
  39         list_for_each_entry_safe(entry, next, &ieee->crypt_deinit_list, list) {
  40                 if (atomic_read(&entry->refcnt) != 0 && !force)
  41                         continue;
  42
  43                 list_del(&entry->list);
  44
  45                 if (entry->ops) {
  46                         entry->ops->deinit(entry->priv);
  47                         module_put(entry->ops->owner);
  48                 }
  49                 kfree(entry);
  50         }
  51         spin_unlock_irqrestore(&ieee->lock, flags);
  52 }
  53
  54 /* After this, crypt_deinit_list won't accept new members */
  55 void ieee80211_crypt_quiescing(struct ieee80211_device *ieee)
  56 {
  57         unsigned long flags;
  58
  59         spin_lock_irqsave(&ieee->lock, flags);
  60         ieee->crypt_quiesced = 1;
  61         spin_unlock_irqrestore(&ieee->lock, flags);
  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         ieee80211_crypt_deinit_entries(ieee, 0);
  70
  71         spin_lock_irqsave(&ieee->lock, flags);
  72         if (!list_empty(&ieee->crypt_deinit_list) && !ieee->crypt_quiesced) {
  73                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
  74                        "deletion list\n", ieee->dev->name);
  75                 ieee->crypt_deinit_timer.expires = jiffies + HZ;
  76                 add_timer(&ieee->crypt_deinit_timer);
  77         }
  78         spin_unlock_irqrestore(&ieee->lock, flags);
  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         if (!ieee->crypt_quiesced) {
  99                 list_add(&tmp->list, &ieee->crypt_deinit_list);
 100                 if (!timer_pending(&ieee->crypt_deinit_timer)) {
 101                         ieee->crypt_deinit_timer.expires = jiffies + HZ;
 102                         add_timer(&ieee->crypt_deinit_timer);
 103                 }
 104         }
 105         spin_unlock_irqrestore(&ieee->lock, flags);
 106 }
 107
 108 int ieee80211_register_crypto_ops(struct ieee80211_crypto_ops *ops)
 109 {
 110         unsigned long flags;
 111         struct ieee80211_crypto_alg *alg;
 112
 113         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 114         if (alg == NULL)
 115                 return -ENOMEM;
 116
 117         alg->ops = ops;
 118
 119         spin_lock_irqsave(&ieee80211_crypto_lock, flags);
 120         list_add(&alg->list, &ieee80211_crypto_algs);
 121         spin_unlock_irqrestore(&ieee80211_crypto_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         struct ieee80211_crypto_alg *alg;
 132         unsigned long flags;
 133
 134         spin_lock_irqsave(&ieee80211_crypto_lock, flags);
 135         list_for_each_entry(alg, &ieee80211_crypto_algs, list) {
 136                 if (alg->ops == ops)
 137                         goto found;
 138         }
 139         spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
 140         return -EINVAL;
 141
 142       found:
 143         printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
 144                "'%s'\n", ops->name);
 145         list_del(&alg->list);
 146         spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
 147         kfree(alg);
 148         return 0;
 149 }
 150
 151 struct ieee80211_crypto_ops *ieee80211_get_crypto_ops(const char *name)
 152 {
 153         struct ieee80211_crypto_alg *alg;
 154         unsigned long flags;
 155
 156         spin_lock_irqsave(&ieee80211_crypto_lock, flags);
 157         list_for_each_entry(alg, &ieee80211_crypto_algs, list) {
 158                 if (strcmp(alg->ops->name, name) == 0)
 159                         goto found;
 160         }
 161         spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
 162         return NULL;
 163
 164       found:
 165         spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
 166         return alg->ops;
 167 }
 168
 169 static void *ieee80211_crypt_null_init(int keyidx)
 170 {
 171         return (void *)1;
 172 }
 173
 174 static void ieee80211_crypt_null_deinit(void *priv)
 175 {
 176 }
 177
 178 static struct ieee80211_crypto_ops ieee80211_crypt_null = {
 179         .name = "NULL",
 180         .init = ieee80211_crypt_null_init,
 181         .deinit = ieee80211_crypt_null_deinit,
 182         .owner = THIS_MODULE,
 183 };
 184
 185 static int __init ieee80211_crypto_init(void)
 186 {
 187         return ieee80211_register_crypto_ops(&ieee80211_crypt_null);
 188 }
 189
 190 static void __exit ieee80211_crypto_deinit(void)
 191 {
 192         ieee80211_unregister_crypto_ops(&ieee80211_crypt_null);
 193         BUG_ON(!list_empty(&ieee80211_crypto_algs));
 194 }
 195
 196 EXPORT_SYMBOL(ieee80211_crypt_deinit_entries);
 197 EXPORT_SYMBOL(ieee80211_crypt_deinit_handler);
 198 EXPORT_SYMBOL(ieee80211_crypt_delayed_deinit);
 199 EXPORT_SYMBOL(ieee80211_crypt_quiescing);
 200
 201 EXPORT_SYMBOL(ieee80211_register_crypto_ops);
 202 EXPORT_SYMBOL(ieee80211_unregister_crypto_ops);
 203 EXPORT_SYMBOL(ieee80211_get_crypto_ops);
 204
 205 module_init(ieee80211_crypto_init);
 206 module_exit(ieee80211_crypto_deinit);