1/*
  2 * lib80211 -- common bits for IEEE802.11 drivers
  3 *
  4 * Copyright(c) 2008 John W. Linville <linville@tuxdriver.com>
  5 *
  6 * Portions copied from old ieee80211 component, w/ original copyright
  7 * notices below:
  8 *
  9 * Host AP crypto routines
 10 *
 11 * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
 12 * Portions Copyright (C) 2004, Intel Corporation <jketreno@linux.intel.com>
 13 *
 14 */
 15
 16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 17
 18#include <linux/module.h>
 19#include <linux/ctype.h>
 20#include <linux/ieee80211.h>
 21#include <linux/errno.h>
 22#include <linux/init.h>
 23#include <linux/slab.h>
 24#include <linux/string.h>
 25
 26#include <net/lib80211.h>
 27
 28#define DRV_NAME        "lib80211"
 29
 30#define DRV_DESCRIPTION	"common routines for IEEE802.11 drivers"
 31
 32MODULE_DESCRIPTION(DRV_DESCRIPTION);
 33MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
 34MODULE_LICENSE("GPL");
 35
 36struct lib80211_crypto_alg {
 37	struct list_head list;
 38	struct lib80211_crypto_ops *ops;
 39};
 40
 41static LIST_HEAD(lib80211_crypto_algs);
 42static DEFINE_SPINLOCK(lib80211_crypto_lock);
 43
 44static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
 45					  int force);
 46static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info);
 47static void lib80211_crypt_deinit_handler(struct timer_list *t);
 48
 49int lib80211_crypt_info_init(struct lib80211_crypt_info *info, char *name,
 50				spinlock_t *lock)
 51{
 52	memset(info, 0, sizeof(*info));
 53
 54	info->name = name;
 55	info->lock = lock;
 56
 57	INIT_LIST_HEAD(&info->crypt_deinit_list);
 58	timer_setup(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
 59		    0);
 60
 61	return 0;
 62}
 63EXPORT_SYMBOL(lib80211_crypt_info_init);
 64
 65void lib80211_crypt_info_free(struct lib80211_crypt_info *info)
 66{
 67	int i;
 68
 69        lib80211_crypt_quiescing(info);
 70        del_timer_sync(&info->crypt_deinit_timer);
 71        lib80211_crypt_deinit_entries(info, 1);
 72
 73        for (i = 0; i < NUM_WEP_KEYS; i++) {
 74                struct lib80211_crypt_data *crypt = info->crypt[i];
 75                if (crypt) {
 76                        if (crypt->ops) {
 77                                crypt->ops->deinit(crypt->priv);
 78                                module_put(crypt->ops->owner);
 79                        }
 80                        kfree(crypt);
 81                        info->crypt[i] = NULL;
 82                }
 83        }
 84}
 85EXPORT_SYMBOL(lib80211_crypt_info_free);
 86
 87static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
 88					  int force)
 89{
 90	struct lib80211_crypt_data *entry, *next;
 91	unsigned long flags;
 92
 93	spin_lock_irqsave(info->lock, flags);
 94	list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
 95		if (atomic_read(&entry->refcnt) != 0 && !force)
 96			continue;
 97
 98		list_del(&entry->list);
 99
100		if (entry->ops) {
101			entry->ops->deinit(entry->priv);
102			module_put(entry->ops->owner);
103		}
104		kfree(entry);
105	}
106	spin_unlock_irqrestore(info->lock, flags);
107}
108
109/* After this, crypt_deinit_list won't accept new members */
110static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info)
111{
112	unsigned long flags;
113
114	spin_lock_irqsave(info->lock, flags);
115	info->crypt_quiesced = 1;
116	spin_unlock_irqrestore(info->lock, flags);
117}
118
119static void lib80211_crypt_deinit_handler(struct timer_list *t)
120{
121	struct lib80211_crypt_info *info = from_timer(info, t,
122						      crypt_deinit_timer);
123	unsigned long flags;
124
125	lib80211_crypt_deinit_entries(info, 0);
126
127	spin_lock_irqsave(info->lock, flags);
128	if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
129		printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
130		       "deletion list\n", info->name);
131		info->crypt_deinit_timer.expires = jiffies + HZ;
132		add_timer(&info->crypt_deinit_timer);
133	}
134	spin_unlock_irqrestore(info->lock, flags);
135}
136
137void lib80211_crypt_delayed_deinit(struct lib80211_crypt_info *info,
138				    struct lib80211_crypt_data **crypt)
139{
140	struct lib80211_crypt_data *tmp;
141	unsigned long flags;
142
143	if (*crypt == NULL)
144		return;
145
146	tmp = *crypt;
147	*crypt = NULL;
148
149	/* must not run ops->deinit() while there may be pending encrypt or
150	 * decrypt operations. Use a list of delayed deinits to avoid needing
151	 * locking. */
152
153	spin_lock_irqsave(info->lock, flags);
154	if (!info->crypt_quiesced) {
155		list_add(&tmp->list, &info->crypt_deinit_list);
156		if (!timer_pending(&info->crypt_deinit_timer)) {
157			info->crypt_deinit_timer.expires = jiffies + HZ;
158			add_timer(&info->crypt_deinit_timer);
159		}
160	}
161	spin_unlock_irqrestore(info->lock, flags);
162}
163EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
164
165int lib80211_register_crypto_ops(struct lib80211_crypto_ops *ops)
166{
167	unsigned long flags;
168	struct lib80211_crypto_alg *alg;
169
170	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
171	if (alg == NULL)
172		return -ENOMEM;
173
174	alg->ops = ops;
175
176	spin_lock_irqsave(&lib80211_crypto_lock, flags);
177	list_add(&alg->list, &lib80211_crypto_algs);
178	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
179
180	printk(KERN_DEBUG "lib80211_crypt: registered algorithm '%s'\n",
181	       ops->name);
182
183	return 0;
184}
185EXPORT_SYMBOL(lib80211_register_crypto_ops);
186
187int lib80211_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
188{
189	struct lib80211_crypto_alg *alg;
190	unsigned long flags;
191
192	spin_lock_irqsave(&lib80211_crypto_lock, flags);
193	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
194		if (alg->ops == ops)
195			goto found;
196	}
197	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
198	return -EINVAL;
199
200      found:
201	printk(KERN_DEBUG "lib80211_crypt: unregistered algorithm '%s'\n",
202	       ops->name);
203	list_del(&alg->list);
204	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
205	kfree(alg);
206	return 0;
207}
208EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
209
210struct lib80211_crypto_ops *lib80211_get_crypto_ops(const char *name)
211{
212	struct lib80211_crypto_alg *alg;
213	unsigned long flags;
214
215	spin_lock_irqsave(&lib80211_crypto_lock, flags);
216	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
217		if (strcmp(alg->ops->name, name) == 0)
218			goto found;
219	}
220	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
221	return NULL;
222
223      found:
224	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
225	return alg->ops;
226}
227EXPORT_SYMBOL(lib80211_get_crypto_ops);
228
229static void *lib80211_crypt_null_init(int keyidx)
230{
231	return (void *)1;
232}
233
234static void lib80211_crypt_null_deinit(void *priv)
235{
236}
237
238static struct lib80211_crypto_ops lib80211_crypt_null = {
239	.name = "NULL",
240	.init = lib80211_crypt_null_init,
241	.deinit = lib80211_crypt_null_deinit,
242	.owner = THIS_MODULE,
243};
244
245static int __init lib80211_init(void)
246{
247	pr_info(DRV_DESCRIPTION "\n");
248	return lib80211_register_crypto_ops(&lib80211_crypt_null);
249}
250
251static void __exit lib80211_exit(void)
252{
253	lib80211_unregister_crypto_ops(&lib80211_crypt_null);
254	BUG_ON(!list_empty(&lib80211_crypto_algs));
255}
256
257module_init(lib80211_init);
258module_exit(lib80211_exit);