root/net/ieee80211/ieee80211_crypt.c

DEFINITIONS

1. ieee80211_crypt_deinit_entries
2. ieee80211_crypt_quiescing
3. ieee80211_crypt_deinit_handler
4. ieee80211_crypt_delayed_deinit
5. ieee80211_register_crypto_ops
6. ieee80211_unregister_crypto_ops
7. ieee80211_get_crypto_ops
8. ieee80211_crypt_null_init
9. ieee80211_crypt_null_deinit
10. ieee80211_crypto_init
11. ieee80211_crypto_deinit

/*
 * Host AP crypto routines
 *
 * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
 * Portions Copyright (C) 2004, Intel Corporation <jketreno@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation. See README and COPYING for
 * more details.
 *
 */

#include <linux/errno.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <net/ieee80211.h>

MODULE_AUTHOR("Jouni Malinen");
MODULE_DESCRIPTION("HostAP crypto");
MODULE_LICENSE("GPL");

struct ieee80211_crypto_alg {
        struct list_head list;
        struct ieee80211_crypto_ops *ops;
};

static LIST_HEAD(ieee80211_crypto_algs);
static DEFINE_SPINLOCK(ieee80211_crypto_lock);

void ieee80211_crypt_deinit_entries(struct ieee80211_device *ieee, int force)
{
        struct ieee80211_crypt_data *entry, *next;
        unsigned long flags;

        spin_lock_irqsave(&ieee->lock, flags);
        list_for_each_entry_safe(entry, next, &ieee->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(&ieee->lock, flags);
}

/* After this, crypt_deinit_list won't accept new members */
void ieee80211_crypt_quiescing(struct ieee80211_device *ieee)
{
        unsigned long flags;

        spin_lock_irqsave(&ieee->lock, flags);
        ieee->crypt_quiesced = 1;
        spin_unlock_irqrestore(&ieee->lock, flags);
}

void ieee80211_crypt_deinit_handler(unsigned long data)
{
        struct ieee80211_device *ieee = (struct ieee80211_device *)data;
        unsigned long flags;

        ieee80211_crypt_deinit_entries(ieee, 0);

        spin_lock_irqsave(&ieee->lock, flags);
        if (!list_empty(&ieee->crypt_deinit_list) && !ieee->crypt_quiesced) {
                printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
                       "deletion list\n", ieee->dev->name);
                ieee->crypt_deinit_timer.expires = jiffies + HZ;
                add_timer(&ieee->crypt_deinit_timer);
        }
        spin_unlock_irqrestore(&ieee->lock, flags);
}

void ieee80211_crypt_delayed_deinit(struct ieee80211_device *ieee,
                                    struct ieee80211_crypt_data **crypt)
{
        struct ieee80211_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(&ieee->lock, flags);
        if (!ieee->crypt_quiesced) {
                list_add(&tmp->list, &ieee->crypt_deinit_list);
                if (!timer_pending(&ieee->crypt_deinit_timer)) {
                        ieee->crypt_deinit_timer.expires = jiffies + HZ;
                        add_timer(&ieee->crypt_deinit_timer);
                }
        }
        spin_unlock_irqrestore(&ieee->lock, flags);
}

int ieee80211_register_crypto_ops(struct ieee80211_crypto_ops *ops)
{
        unsigned long flags;
        struct ieee80211_crypto_alg *alg;

        alg = kzalloc(sizeof(*alg), GFP_KERNEL);
        if (alg == NULL)
                return -ENOMEM;

        alg->ops = ops;

        spin_lock_irqsave(&ieee80211_crypto_lock, flags);
        list_add(&alg->list, &ieee80211_crypto_algs);
        spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);

        printk(KERN_DEBUG "ieee80211_crypt: registered algorithm '%s'\n",
               ops->name);

        return 0;
}

int ieee80211_unregister_crypto_ops(struct ieee80211_crypto_ops *ops)
{
        struct ieee80211_crypto_alg *alg;
        unsigned long flags;

        spin_lock_irqsave(&ieee80211_crypto_lock, flags);
        list_for_each_entry(alg, &ieee80211_crypto_algs, list) {
                if (alg->ops == ops)
                        goto found;
        }
        spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
        return -EINVAL;

      found:
        printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
               "'%s'\n", ops->name);
        list_del(&alg->list);
        spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
        kfree(alg);
        return 0;
}

struct ieee80211_crypto_ops *ieee80211_get_crypto_ops(const char *name)
{
        struct ieee80211_crypto_alg *alg;
        unsigned long flags;

        spin_lock_irqsave(&ieee80211_crypto_lock, flags);
        list_for_each_entry(alg, &ieee80211_crypto_algs, list) {
                if (strcmp(alg->ops->name, name) == 0)
                        goto found;
        }
        spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
        return NULL;

      found:
        spin_unlock_irqrestore(&ieee80211_crypto_lock, flags);
        return alg->ops;
}

static void *ieee80211_crypt_null_init(int keyidx)
{
        return (void *)1;
}

static void ieee80211_crypt_null_deinit(void *priv)
{
}

static struct ieee80211_crypto_ops ieee80211_crypt_null = {
        .name = "NULL",
        .init = ieee80211_crypt_null_init,
        .deinit = ieee80211_crypt_null_deinit,
        .owner = THIS_MODULE,
};

static int __init ieee80211_crypto_init(void)
{
        return ieee80211_register_crypto_ops(&ieee80211_crypt_null);
}

static void __exit ieee80211_crypto_deinit(void)
{
        ieee80211_unregister_crypto_ops(&ieee80211_crypt_null);
        BUG_ON(!list_empty(&ieee80211_crypto_algs));
}

EXPORT_SYMBOL(ieee80211_crypt_deinit_entries);
EXPORT_SYMBOL(ieee80211_crypt_deinit_handler);
EXPORT_SYMBOL(ieee80211_crypt_delayed_deinit);
EXPORT_SYMBOL(ieee80211_crypt_quiescing);

EXPORT_SYMBOL(ieee80211_register_crypto_ops);
EXPORT_SYMBOL(ieee80211_unregister_crypto_ops);
EXPORT_SYMBOL(ieee80211_get_crypto_ops);

module_init(ieee80211_crypto_init);
module_exit(ieee80211_crypto_deinit);