drivers/staging/rtl8192e/rtllib_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/version.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 "rtllib.h"
  22
  23 struct rtllib_crypto_alg {
  24         struct list_head list;
  25         struct rtllib_crypto_ops *ops;
  26 };
  27
  28
  29 struct rtllib_crypto {
  30         struct list_head algs;
  31         spinlock_t lock;
  32 };
  33
  34 static struct rtllib_crypto *hcrypt;
  35
  36 void rtllib_crypt_deinit_entries(struct rtllib_device *ieee,
  37                                            int force)
  38 {
  39         struct list_head *ptr, *n;
  40         struct rtllib_crypt_data *entry;
  41
  42         for (ptr = ieee->crypt_deinit_list.next, n = ptr->next;
  43              ptr != &ieee->crypt_deinit_list; ptr = n, n = ptr->next) {
  44                 entry = list_entry(ptr, struct rtllib_crypt_data, list);
  45
  46                 if (atomic_read(&entry->refcnt) != 0 && !force)
  47                         continue;
  48
  49                 list_del(ptr);
  50
  51                 if (entry->ops)
  52                         entry->ops->deinit(entry->priv);
  53                 kfree(entry);
  54         }
  55 }
  56
  57 void rtllib_crypt_deinit_handler(unsigned long data)
  58 {
  59         struct rtllib_device *ieee = (struct rtllib_device *)data;
  60         unsigned long flags;
  61
  62         spin_lock_irqsave(&ieee->lock, flags);
  63         rtllib_crypt_deinit_entries(ieee, 0);
  64         if (!list_empty(&ieee->crypt_deinit_list)) {
  65                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
  66                        "deletion list\n", ieee->dev->name);
  67                 ieee->crypt_deinit_timer.expires = jiffies + HZ;
  68                 add_timer(&ieee->crypt_deinit_timer);
  69         }
  70         spin_unlock_irqrestore(&ieee->lock, flags);
  71
  72 }
  73
  74 void rtllib_crypt_delayed_deinit(struct rtllib_device *ieee,
  75                                     struct rtllib_crypt_data **crypt)
  76 {
  77         struct rtllib_crypt_data *tmp;
  78         unsigned long flags;
  79
  80         if (*crypt == NULL)
  81                 return;
  82
  83         tmp = *crypt;
  84         *crypt = NULL;
  85
  86         /* must not run ops->deinit() while there may be pending encrypt or
  87          * decrypt operations. Use a list of delayed deinits to avoid needing
  88          * locking. */
  89
  90         spin_lock_irqsave(&ieee->lock, flags);
  91         list_add(&tmp->list, &ieee->crypt_deinit_list);
  92         if (!timer_pending(&ieee->crypt_deinit_timer)) {
  93                 ieee->crypt_deinit_timer.expires = jiffies + HZ;
  94                 add_timer(&ieee->crypt_deinit_timer);
  95         }
  96         spin_unlock_irqrestore(&ieee->lock, flags);
  97 }
  98
  99 int rtllib_register_crypto_ops(struct rtllib_crypto_ops *ops)
 100 {
 101         unsigned long flags;
 102         struct rtllib_crypto_alg *alg;
 103
 104         if (hcrypt == NULL)
 105                 return -1;
 106
 107         alg = kmalloc(sizeof(*alg), GFP_KERNEL);
 108         if (alg == NULL)
 109                 return -ENOMEM;
 110
 111         memset(alg, 0, sizeof(*alg));
 112         alg->ops = ops;
 113
 114         spin_lock_irqsave(&hcrypt->lock, flags);
 115         list_add(&alg->list, &hcrypt->algs);
 116         spin_unlock_irqrestore(&hcrypt->lock, flags);
 117
 118         printk(KERN_DEBUG "rtllib_crypt: registered algorithm '%s'\n",
 119                ops->name);
 120
 121         return 0;
 122 }
 123
 124 int rtllib_unregister_crypto_ops(struct rtllib_crypto_ops *ops)
 125 {
 126         unsigned long flags;
 127         struct list_head *ptr;
 128         struct rtllib_crypto_alg *del_alg = NULL;
 129
 130         if (hcrypt == NULL)
 131                 return -1;
 132
 133         spin_lock_irqsave(&hcrypt->lock, flags);
 134         for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
 135                 struct rtllib_crypto_alg *alg =
 136                         (struct rtllib_crypto_alg *) ptr;
 137                 if (alg->ops == ops) {
 138                         list_del(&alg->list);
 139                         del_alg = alg;
 140                         break;
 141                 }
 142         }
 143         spin_unlock_irqrestore(&hcrypt->lock, flags);
 144
 145         if (del_alg) {
 146                 printk(KERN_DEBUG "rtllib_crypt: unregistered algorithm "
 147                        "'%s'\n", ops->name);
 148                 kfree(del_alg);
 149         }
 150
 151         return del_alg ? 0 : -1;
 152 }
 153
 154
 155 struct rtllib_crypto_ops * rtllib_get_crypto_ops(const char *name)
 156 {
 157         unsigned long flags;
 158         struct list_head *ptr;
 159         struct rtllib_crypto_alg *found_alg = NULL;
 160
 161         if (hcrypt == NULL)
 162                 return NULL;
 163
 164         spin_lock_irqsave(&hcrypt->lock, flags);
 165         for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
 166                 struct rtllib_crypto_alg *alg =
 167                         (struct rtllib_crypto_alg *) ptr;
 168                 if (strcmp(alg->ops->name, name) == 0) {
 169                         found_alg = alg;
 170                         break;
 171                 }
 172         }
 173         spin_unlock_irqrestore(&hcrypt->lock, flags);
 174
 175         if (found_alg)
 176                 return found_alg->ops;
 177         else
 178                 return NULL;
 179 }
 180
 181
 182 static void * rtllib_crypt_null_init(int keyidx) { return (void *) 1; }
 183 static void rtllib_crypt_null_deinit(void *priv) {}
 184
 185 static struct rtllib_crypto_ops rtllib_crypt_null = {
 186         .name                   = "NULL",
 187         .init                   = rtllib_crypt_null_init,
 188         .deinit                 = rtllib_crypt_null_deinit,
 189         .encrypt_mpdu           = NULL,
 190         .decrypt_mpdu           = NULL,
 191         .encrypt_msdu           = NULL,
 192         .decrypt_msdu           = NULL,
 193         .set_key                = NULL,
 194         .get_key                = NULL,
 195         .extra_prefix_len       = 0,
 196         .extra_postfix_len      = 0,
 197         .owner                  = THIS_MODULE,
 198 };
 199
 200
 201 int __init rtllib_crypto_init(void)
 202 {
 203         int ret = -ENOMEM;
 204
 205         hcrypt = kmalloc(sizeof(*hcrypt), GFP_KERNEL);
 206         if (!hcrypt)
 207                 goto out;
 208
 209         memset(hcrypt, 0, sizeof(*hcrypt));
 210         INIT_LIST_HEAD(&hcrypt->algs);
 211         spin_lock_init(&hcrypt->lock);
 212
 213         ret = rtllib_register_crypto_ops(&rtllib_crypt_null);
 214         if (ret < 0) {
 215                 kfree(hcrypt);
 216                 hcrypt = NULL;
 217         }
 218 out:
 219         return ret;
 220 }
 221
 222
 223 void __exit rtllib_crypto_deinit(void)
 224 {
 225         struct list_head *ptr, *n;
 226
 227         if (hcrypt == NULL)
 228                 return;
 229
 230         for (ptr = hcrypt->algs.next, n = ptr->next; ptr != &hcrypt->algs;
 231              ptr = n, n = ptr->next) {
 232                 struct rtllib_crypto_alg *alg =
 233                         (struct rtllib_crypto_alg *) ptr;
 234                 list_del(ptr);
 235                 printk(KERN_DEBUG "rtllib_crypt: unregistered algorithm "
 236                        "'%s' (deinit)\n", alg->ops->name);
 237                 kfree(alg);
 238         }
 239
 240         kfree(hcrypt);
 241 }