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(unsigned long data);
 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	setup_timer(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
 59			(unsigned long)info);
 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(unsigned long data)
120{
121	struct lib80211_crypt_info *info = (struct lib80211_crypt_info *)data;
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
136void 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}
162EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
163
164int 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}
184EXPORT_SYMBOL(lib80211_register_crypto_ops);
185
186int 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}
207EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
208
209struct 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}
226EXPORT_SYMBOL(lib80211_get_crypto_ops);
227
228static void *lib80211_crypt_null_init(int keyidx)
229{
230	return (void *)1;
231}
232
233static void lib80211_crypt_null_deinit(void *priv)
234{
235}
236
237static 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
244static int __init lib80211_init(void)
245{
246	pr_info(DRV_DESCRIPTION "\n");
247	return lib80211_register_crypto_ops(&lib80211_crypt_null);
248}
249
250static void __exit lib80211_exit(void)
251{
252	lib80211_unregister_crypto_ops(&lib80211_crypt_null);
253	BUG_ON(!list_empty(&lib80211_crypto_algs));
254}
255
256module_init(lib80211_init);
257module_exit(lib80211_exit);