/*
   * lib80211 -- common bits for IEEE802.11 drivers
   *
   * Copyright(c) 2008 John W. Linville <linville@tuxdriver.com>
   *

   * Portions copied from old ieee80211 component, w/ original copyright
   * notices below:
   *
   * Host AP crypto routines
   *
   * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
   * Portions Copyright (C) 2004, Intel Corporation <jketreno@linux.intel.com>
   *

   */

  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

  #include <linux/module.h>

  #include <linux/ctype.h>

  #include <linux/ieee80211.h>

  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/slab.h>
  #include <linux/string.h>

  
  #include <net/lib80211.h>
  
  #define DRV_NAME        "lib80211"
  
  #define DRV_DESCRIPTION	"common routines for IEEE802.11 drivers"
  
  MODULE_DESCRIPTION(DRV_DESCRIPTION);
  MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
  MODULE_LICENSE("GPL");

  struct lib80211_crypto_alg {
  	struct list_head list;
  	struct lib80211_crypto_ops *ops;
  };
  
  static LIST_HEAD(lib80211_crypto_algs);
  static DEFINE_SPINLOCK(lib80211_crypto_lock);

  static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
  					  int force);
  static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info);
  static void lib80211_crypt_deinit_handler(unsigned long data);

  int lib80211_crypt_info_init(struct lib80211_crypt_info *info, char *name,
  				spinlock_t *lock)
  {
  	memset(info, 0, sizeof(*info));
  
  	info->name = name;
  	info->lock = lock;
  
  	INIT_LIST_HEAD(&info->crypt_deinit_list);
  	setup_timer(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
  			(unsigned long)info);
  
  	return 0;
  }
  EXPORT_SYMBOL(lib80211_crypt_info_init);
  
  void lib80211_crypt_info_free(struct lib80211_crypt_info *info)
  {
  	int i;
  
          lib80211_crypt_quiescing(info);
          del_timer_sync(&info->crypt_deinit_timer);
          lib80211_crypt_deinit_entries(info, 1);
  
          for (i = 0; i < NUM_WEP_KEYS; i++) {
                  struct lib80211_crypt_data *crypt = info->crypt[i];
                  if (crypt) {
                          if (crypt->ops) {
                                  crypt->ops->deinit(crypt->priv);
                                  module_put(crypt->ops->owner);
                          }
                          kfree(crypt);
                          info->crypt[i] = NULL;
                  }
          }
  }
  EXPORT_SYMBOL(lib80211_crypt_info_free);

  static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
  					  int force)

  {

  	struct lib80211_crypt_data *entry, *next;
  	unsigned long flags;
  
  	spin_lock_irqsave(info->lock, flags);
  	list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
  		if (atomic_read(&entry->refcnt) != 0 && !force)
  			continue;
  
  		list_del(&entry->list);
  
  		if (entry->ops) {
  			entry->ops->deinit(entry->priv);
  			module_put(entry->ops->owner);
  		}
  		kfree(entry);
  	}
  	spin_unlock_irqrestore(info->lock, flags);
  }

  
  /* After this, crypt_deinit_list won't accept new members */

  static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info)

  {
  	unsigned long flags;
  
  	spin_lock_irqsave(info->lock, flags);
  	info->crypt_quiesced = 1;
  	spin_unlock_irqrestore(info->lock, flags);
  }

  static void lib80211_crypt_deinit_handler(unsigned long data)

  {
  	struct lib80211_crypt_info *info = (struct lib80211_crypt_info *)data;
  	unsigned long flags;
  
  	lib80211_crypt_deinit_entries(info, 0);
  
  	spin_lock_irqsave(info->lock, flags);
  	if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
  		printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
  		       "deletion list
  ", info->name);
  		info->crypt_deinit_timer.expires = jiffies + HZ;
  		add_timer(&info->crypt_deinit_timer);
  	}
  	spin_unlock_irqrestore(info->lock, flags);
  }

  
  void lib80211_crypt_delayed_deinit(struct lib80211_crypt_info *info,
  				    struct lib80211_crypt_data **crypt)
  {
  	struct lib80211_crypt_data *tmp;
  	unsigned long flags;
  
  	if (*crypt == NULL)
  		return;
  
  	tmp = *crypt;
  	*crypt = NULL;
  
  	/* must not run ops->deinit() while there may be pending encrypt or
  	 * decrypt operations. Use a list of delayed deinits to avoid needing
  	 * locking. */
  
  	spin_lock_irqsave(info->lock, flags);
  	if (!info->crypt_quiesced) {
  		list_add(&tmp->list, &info->crypt_deinit_list);
  		if (!timer_pending(&info->crypt_deinit_timer)) {
  			info->crypt_deinit_timer.expires = jiffies + HZ;
  			add_timer(&info->crypt_deinit_timer);
  		}
  	}
  	spin_unlock_irqrestore(info->lock, flags);
  }
  EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
  
  int lib80211_register_crypto_ops(struct lib80211_crypto_ops *ops)
  {
  	unsigned long flags;
  	struct lib80211_crypto_alg *alg;
  
  	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
  	if (alg == NULL)
  		return -ENOMEM;
  
  	alg->ops = ops;
  
  	spin_lock_irqsave(&lib80211_crypto_lock, flags);
  	list_add(&alg->list, &lib80211_crypto_algs);
  	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
  
  	printk(KERN_DEBUG "lib80211_crypt: registered algorithm '%s'
  ",
  	       ops->name);
  
  	return 0;
  }
  EXPORT_SYMBOL(lib80211_register_crypto_ops);
  
  int lib80211_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
  {
  	struct lib80211_crypto_alg *alg;
  	unsigned long flags;
  
  	spin_lock_irqsave(&lib80211_crypto_lock, flags);
  	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
  		if (alg->ops == ops)
  			goto found;
  	}
  	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
  	return -EINVAL;
  
        found:

  	printk(KERN_DEBUG "lib80211_crypt: unregistered algorithm '%s'
  ",
  	       ops->name);

  	list_del(&alg->list);
  	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
  	kfree(alg);

  	return 0;
  }

  EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
  
  struct lib80211_crypto_ops *lib80211_get_crypto_ops(const char *name)
  {
  	struct lib80211_crypto_alg *alg;
  	unsigned long flags;
  
  	spin_lock_irqsave(&lib80211_crypto_lock, flags);
  	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
  		if (strcmp(alg->ops->name, name) == 0)
  			goto found;
  	}
  	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
  	return NULL;
  
        found:
  	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
  	return alg->ops;
  }
  EXPORT_SYMBOL(lib80211_get_crypto_ops);
  
  static void *lib80211_crypt_null_init(int keyidx)
  {
  	return (void *)1;
  }
  
  static void lib80211_crypt_null_deinit(void *priv)
  {
  }
  
  static struct lib80211_crypto_ops lib80211_crypt_null = {
  	.name = "NULL",
  	.init = lib80211_crypt_null_init,
  	.deinit = lib80211_crypt_null_deinit,
  	.owner = THIS_MODULE,
  };
  
  static int __init lib80211_init(void)
  {

  	pr_info(DRV_DESCRIPTION "
  ");

  	return lib80211_register_crypto_ops(&lib80211_crypt_null);
  }

  static void __exit lib80211_exit(void)

  {

  	lib80211_unregister_crypto_ops(&lib80211_crypt_null);
  	BUG_ON(!list_empty(&lib80211_crypto_algs));

  }

  module_init(lib80211_init);
  module_exit(lib80211_exit);