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