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