net/wireless/lib80211.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * lib80211 -- common bits for IEEE802.11 drivers
   4  *
   5  * Copyright(c) 2008 John W. Linville <linville@tuxdriver.com>
   6  *
   7  * Portions copied from old ieee80211 component, w/ original copyright
   8  * notices below:
   9  *
  10  * Host AP crypto routines
  11  *
  12  * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
  13  * Portions Copyright (C) 2004, Intel Corporation <jketreno@linux.intel.com>
  14  *
  15  */
  16
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/module.h>
  20 #include <linux/ctype.h>
  21 #include <linux/ieee80211.h>
  22 #include <linux/errno.h>
  23 #include <linux/init.h>
  24 #include <linux/slab.h>
  25 #include <linux/string.h>
  26
  27 #include <net/lib80211.h>
  28
  29 #define DRV_DESCRIPTION "common routines for IEEE802.11 drivers"
  30
  31 MODULE_DESCRIPTION(DRV_DESCRIPTION);
  32 MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
  33 MODULE_LICENSE("GPL");
  34
  35 struct lib80211_crypto_alg {
  36         struct list_head list;
  37         struct lib80211_crypto_ops *ops;
  38 };
  39
  40 static LIST_HEAD(lib80211_crypto_algs);
  41 static DEFINE_SPINLOCK(lib80211_crypto_lock);
  42
  43 static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
  44                                           int force);
  45 static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info);
  46 static void lib80211_crypt_deinit_handler(struct timer_list *t);
  47
  48 int lib80211_crypt_info_init(struct lib80211_crypt_info *info, char *name,
  49                                 spinlock_t *lock)
  50 {
  51         memset(info, 0, sizeof(*info));
  52
  53         info->name = name;
  54         info->lock = lock;
  55
  56         INIT_LIST_HEAD(&info->crypt_deinit_list);
  57         timer_setup(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
  58                     0);
  59
  60         return 0;
  61 }
  62 EXPORT_SYMBOL(lib80211_crypt_info_init);
  63
  64 void lib80211_crypt_info_free(struct lib80211_crypt_info *info)
  65 {
  66         int i;
  67
  68         lib80211_crypt_quiescing(info);
  69         del_timer_sync(&info->crypt_deinit_timer);
  70         lib80211_crypt_deinit_entries(info, 1);
  71
  72         for (i = 0; i < NUM_WEP_KEYS; i++) {
  73                 struct lib80211_crypt_data *crypt = info->crypt[i];
  74                 if (crypt) {
  75                         if (crypt->ops) {
  76                                 crypt->ops->deinit(crypt->priv);
  77                                 module_put(crypt->ops->owner);
  78                         }
  79                         kfree(crypt);
  80                         info->crypt[i] = NULL;
  81                 }
  82         }
  83 }
  84 EXPORT_SYMBOL(lib80211_crypt_info_free);
  85
  86 static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
  87                                           int force)
  88 {
  89         struct lib80211_crypt_data *entry, *next;
  90         unsigned long flags;
  91
  92         spin_lock_irqsave(info->lock, flags);
  93         list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
  94                 if (atomic_read(&entry->refcnt) != 0 && !force)
  95                         continue;
  96
  97                 list_del(&entry->list);
  98
  99                 if (entry->ops) {
 100                         entry->ops->deinit(entry->priv);
 101                         module_put(entry->ops->owner);
 102                 }
 103                 kfree(entry);
 104         }
 105         spin_unlock_irqrestore(info->lock, flags);
 106 }
 107
 108 /* After this, crypt_deinit_list won't accept new members */
 109 static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info)
 110 {
 111         unsigned long flags;
 112
 113         spin_lock_irqsave(info->lock, flags);
 114         info->crypt_quiesced = 1;
 115         spin_unlock_irqrestore(info->lock, flags);
 116 }
 117
 118 static void lib80211_crypt_deinit_handler(struct timer_list *t)
 119 {
 120         struct lib80211_crypt_info *info = from_timer(info, t,
 121                                                       crypt_deinit_timer);
 122         unsigned long flags;
 123
 124         lib80211_crypt_deinit_entries(info, 0);
 125
 126         spin_lock_irqsave(info->lock, flags);
 127         if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
 128                 printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
 129                        "deletion list\n", info->name);
 130                 info->crypt_deinit_timer.expires = jiffies + HZ;
 131                 add_timer(&info->crypt_deinit_timer);
 132         }
 133         spin_unlock_irqrestore(info->lock, flags);
 134 }
 135
 136 void lib80211_crypt_delayed_deinit(struct lib80211_crypt_info *info,
 137                                     struct lib80211_crypt_data **crypt)
 138 {
 139         struct lib80211_crypt_data *tmp;
 140         unsigned long flags;
 141
 142         if (*crypt == NULL)
 143                 return;
 144
 145         tmp = *crypt;
 146         *crypt = NULL;
 147
 148         /* must not run ops->deinit() while there may be pending encrypt or
 149          * decrypt operations. Use a list of delayed deinits to avoid needing
 150          * locking. */
 151
 152         spin_lock_irqsave(info->lock, flags);
 153         if (!info->crypt_quiesced) {
 154                 list_add(&tmp->list, &info->crypt_deinit_list);
 155                 if (!timer_pending(&info->crypt_deinit_timer)) {
 156                         info->crypt_deinit_timer.expires = jiffies + HZ;
 157                         add_timer(&info->crypt_deinit_timer);
 158                 }
 159         }
 160         spin_unlock_irqrestore(info->lock, flags);
 161 }
 162 EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
 163
 164 int lib80211_register_crypto_ops(struct lib80211_crypto_ops *ops)
 165 {
 166         unsigned long flags;
 167         struct lib80211_crypto_alg *alg;
 168
 169         alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 170         if (alg == NULL)
 171                 return -ENOMEM;
 172
 173         alg->ops = ops;
 174
 175         spin_lock_irqsave(&lib80211_crypto_lock, flags);
 176         list_add(&alg->list, &lib80211_crypto_algs);
 177         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 178
 179         printk(KERN_DEBUG "lib80211_crypt: registered algorithm '%s'\n",
 180                ops->name);
 181
 182         return 0;
 183 }
 184 EXPORT_SYMBOL(lib80211_register_crypto_ops);
 185
 186 int lib80211_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
 187 {
 188         struct lib80211_crypto_alg *alg;
 189         unsigned long flags;
 190
 191         spin_lock_irqsave(&lib80211_crypto_lock, flags);
 192         list_for_each_entry(alg, &lib80211_crypto_algs, list) {
 193                 if (alg->ops == ops)
 194                         goto found;
 195         }
 196         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 197         return -EINVAL;
 198
 199       found:
 200         printk(KERN_DEBUG "lib80211_crypt: unregistered algorithm '%s'\n",
 201                ops->name);
 202         list_del(&alg->list);
 203         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 204         kfree(alg);
 205         return 0;
 206 }
 207 EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
 208
 209 struct lib80211_crypto_ops *lib80211_get_crypto_ops(const char *name)
 210 {
 211         struct lib80211_crypto_alg *alg;
 212         unsigned long flags;
 213
 214         spin_lock_irqsave(&lib80211_crypto_lock, flags);
 215         list_for_each_entry(alg, &lib80211_crypto_algs, list) {
 216                 if (strcmp(alg->ops->name, name) == 0)
 217                         goto found;
 218         }
 219         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 220         return NULL;
 221
 222       found:
 223         spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
 224         return alg->ops;
 225 }
 226 EXPORT_SYMBOL(lib80211_get_crypto_ops);
 227
 228 static void *lib80211_crypt_null_init(int keyidx)
 229 {
 230         return (void *)1;
 231 }
 232
 233 static void lib80211_crypt_null_deinit(void *priv)
 234 {
 235 }
 236
 237 static struct lib80211_crypto_ops lib80211_crypt_null = {
 238         .name = "NULL",
 239         .init = lib80211_crypt_null_init,
 240         .deinit = lib80211_crypt_null_deinit,
 241         .owner = THIS_MODULE,
 242 };
 243
 244 static int __init lib80211_init(void)
 245 {
 246         pr_info(DRV_DESCRIPTION "\n");
 247         return lib80211_register_crypto_ops(&lib80211_crypt_null);
 248 }
 249
 250 static void __exit lib80211_exit(void)
 251 {
 252         lib80211_unregister_crypto_ops(&lib80211_crypt_null);
 253         BUG_ON(!list_empty(&lib80211_crypto_algs));
 254 }
 255
 256 module_init(lib80211_init);
 257 module_exit(lib80211_exit);