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  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
 49const char *print_ssid(char *buf, const char *ssid, u8 ssid_len)
 50{
 51	const char *s = ssid;
 52	char *d = buf;
 53
 54	ssid_len = min_t(u8, ssid_len, IEEE80211_MAX_SSID_LEN);
 55	while (ssid_len--) {
 56		if (isprint(*s)) {
 57			*d++ = *s++;
 58			continue;
 59		}
 60
 61		*d++ = '\\';
 62		if (*s == '\0')
 63			*d++ = '0';
 64		else if (*s == '\n')
 65			*d++ = 'n';
 66		else if (*s == '\r')
 67			*d++ = 'r';
 68		else if (*s == '\t')
 69			*d++ = 't';
 70		else if (*s == '\\')
 71			*d++ = '\\';
 72		else
 73			d += snprintf(d, 3, "%03o", *s);
 74		s++;
 75	}
 76	*d = '\0';
 77	return buf;
 78}
 79EXPORT_SYMBOL(print_ssid);
 80
 81int lib80211_crypt_info_init(struct lib80211_crypt_info *info, char *name,
 82				spinlock_t *lock)
 83{
 84	memset(info, 0, sizeof(*info));
 85
 86	info->name = name;
 87	info->lock = lock;
 88
 89	INIT_LIST_HEAD(&info->crypt_deinit_list);
 90	setup_timer(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
 91			(unsigned long)info);
 92
 93	return 0;
 94}
 95EXPORT_SYMBOL(lib80211_crypt_info_init);
 96
 97void lib80211_crypt_info_free(struct lib80211_crypt_info *info)
 98{
 99	int i;
100
101        lib80211_crypt_quiescing(info);
102        del_timer_sync(&info->crypt_deinit_timer);
103        lib80211_crypt_deinit_entries(info, 1);
104
105        for (i = 0; i < NUM_WEP_KEYS; i++) {
106                struct lib80211_crypt_data *crypt = info->crypt[i];
107                if (crypt) {
108                        if (crypt->ops) {
109                                crypt->ops->deinit(crypt->priv);
110                                module_put(crypt->ops->owner);
111                        }
112                        kfree(crypt);
113                        info->crypt[i] = NULL;
114                }
115        }
116}
117EXPORT_SYMBOL(lib80211_crypt_info_free);
118
119static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
120					  int force)
121{
122	struct lib80211_crypt_data *entry, *next;
123	unsigned long flags;
124
125	spin_lock_irqsave(info->lock, flags);
126	list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
127		if (atomic_read(&entry->refcnt) != 0 && !force)
128			continue;
129
130		list_del(&entry->list);
131
132		if (entry->ops) {
133			entry->ops->deinit(entry->priv);
134			module_put(entry->ops->owner);
135		}
136		kfree(entry);
137	}
138	spin_unlock_irqrestore(info->lock, flags);
139}
140
141/* After this, crypt_deinit_list won't accept new members */
142static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info)
143{
144	unsigned long flags;
145
146	spin_lock_irqsave(info->lock, flags);
147	info->crypt_quiesced = 1;
148	spin_unlock_irqrestore(info->lock, flags);
149}
150
151static void lib80211_crypt_deinit_handler(unsigned long data)
152{
153	struct lib80211_crypt_info *info = (struct lib80211_crypt_info *)data;
154	unsigned long flags;
155
156	lib80211_crypt_deinit_entries(info, 0);
157
158	spin_lock_irqsave(info->lock, flags);
159	if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
160		printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
161		       "deletion list\n", info->name);
162		info->crypt_deinit_timer.expires = jiffies + HZ;
163		add_timer(&info->crypt_deinit_timer);
164	}
165	spin_unlock_irqrestore(info->lock, flags);
166}
167
168void lib80211_crypt_delayed_deinit(struct lib80211_crypt_info *info,
169				    struct lib80211_crypt_data **crypt)
170{
171	struct lib80211_crypt_data *tmp;
172	unsigned long flags;
173
174	if (*crypt == NULL)
175		return;
176
177	tmp = *crypt;
178	*crypt = NULL;
179
180	/* must not run ops->deinit() while there may be pending encrypt or
181	 * decrypt operations. Use a list of delayed deinits to avoid needing
182	 * locking. */
183
184	spin_lock_irqsave(info->lock, flags);
185	if (!info->crypt_quiesced) {
186		list_add(&tmp->list, &info->crypt_deinit_list);
187		if (!timer_pending(&info->crypt_deinit_timer)) {
188			info->crypt_deinit_timer.expires = jiffies + HZ;
189			add_timer(&info->crypt_deinit_timer);
190		}
191	}
192	spin_unlock_irqrestore(info->lock, flags);
193}
194EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
195
196int lib80211_register_crypto_ops(struct lib80211_crypto_ops *ops)
197{
198	unsigned long flags;
199	struct lib80211_crypto_alg *alg;
200
201	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
202	if (alg == NULL)
203		return -ENOMEM;
204
205	alg->ops = ops;
206
207	spin_lock_irqsave(&lib80211_crypto_lock, flags);
208	list_add(&alg->list, &lib80211_crypto_algs);
209	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
210
211	printk(KERN_DEBUG "lib80211_crypt: registered algorithm '%s'\n",
212	       ops->name);
213
214	return 0;
215}
216EXPORT_SYMBOL(lib80211_register_crypto_ops);
217
218int lib80211_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
219{
220	struct lib80211_crypto_alg *alg;
221	unsigned long flags;
222
223	spin_lock_irqsave(&lib80211_crypto_lock, flags);
224	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
225		if (alg->ops == ops)
226			goto found;
227	}
228	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
229	return -EINVAL;
230
231      found:
232	printk(KERN_DEBUG "lib80211_crypt: unregistered algorithm '%s'\n",
233	       ops->name);
234	list_del(&alg->list);
235	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
236	kfree(alg);
237	return 0;
238}
239EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
240
241struct lib80211_crypto_ops *lib80211_get_crypto_ops(const char *name)
242{
243	struct lib80211_crypto_alg *alg;
244	unsigned long flags;
245
246	spin_lock_irqsave(&lib80211_crypto_lock, flags);
247	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
248		if (strcmp(alg->ops->name, name) == 0)
249			goto found;
250	}
251	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
252	return NULL;
253
254      found:
255	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
256	return alg->ops;
257}
258EXPORT_SYMBOL(lib80211_get_crypto_ops);
259
260static void *lib80211_crypt_null_init(int keyidx)
261{
262	return (void *)1;
263}
264
265static void lib80211_crypt_null_deinit(void *priv)
266{
267}
268
269static struct lib80211_crypto_ops lib80211_crypt_null = {
270	.name = "NULL",
271	.init = lib80211_crypt_null_init,
272	.deinit = lib80211_crypt_null_deinit,
273	.owner = THIS_MODULE,
274};
275
276static int __init lib80211_init(void)
277{
278	pr_info(DRV_DESCRIPTION "\n");
279	return lib80211_register_crypto_ops(&lib80211_crypt_null);
280}
281
282static void __exit lib80211_exit(void)
283{
284	lib80211_unregister_crypto_ops(&lib80211_crypt_null);
285	BUG_ON(!list_empty(&lib80211_crypto_algs));
286}
287
288module_init(lib80211_init);
289module_exit(lib80211_exit);