summaryrefslogtreecommitdiffstats
path: root/net/ieee80211/ieee80211_crypt.c
blob: 05a6f2f298db4a4d61d388642d7d6f9fc37b23a7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
/*
 * Host AP crypto routines
 *
 * Copyright (c) 2002-2003, Jouni Malinen <jkmaline@cc.hut.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/config.h>
#include <linux/version.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <asm/string.h>
#include <asm/errno.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;
};


struct ieee80211_crypto {
	struct list_head algs;
	spinlock_t lock;
};

static struct ieee80211_crypto *hcrypt;

void ieee80211_crypt_deinit_entries(struct ieee80211_device *ieee,
					   int force)
{
	struct list_head *ptr, *n;
	struct ieee80211_crypt_data *entry;

	for (ptr = ieee->crypt_deinit_list.next, n = ptr->next;
	     ptr != &ieee->crypt_deinit_list; ptr = n, n = ptr->next) {
		entry = list_entry(ptr, struct ieee80211_crypt_data, list);

		if (atomic_read(&entry->refcnt) != 0 && !force)
			continue;

		list_del(ptr);

		if (entry->ops) {
			entry->ops->deinit(entry->priv);
			module_put(entry->ops->owner);
		}
		kfree(entry);
	}
}

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

	spin_lock_irqsave(&ieee->lock, flags);
	ieee80211_crypt_deinit_entries(ieee, 0);
	if (!list_empty(&ieee->crypt_deinit_list)) {
		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);
	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;

	if (hcrypt == NULL)
		return -1;

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

	memset(alg, 0, sizeof(*alg));
	alg->ops = ops;

	spin_lock_irqsave(&hcrypt->lock, flags);
	list_add(&alg->list, &hcrypt->algs);
	spin_unlock_irqrestore(&hcrypt->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)
{
	unsigned long flags;
	struct list_head *ptr;
	struct ieee80211_crypto_alg *del_alg = NULL;

	if (hcrypt == NULL)
		return -1;

	spin_lock_irqsave(&hcrypt->lock, flags);
	for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
		struct ieee80211_crypto_alg *alg =
			(struct ieee80211_crypto_alg *) ptr;
		if (alg->ops == ops) {
			list_del(&alg->list);
			del_alg = alg;
			break;
		}
	}
	spin_unlock_irqrestore(&hcrypt->lock, flags);

	if (del_alg) {
		printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
		       "'%s'\n", ops->name);
		kfree(del_alg);
	}

	return del_alg ? 0 : -1;
}


struct ieee80211_crypto_ops * ieee80211_get_crypto_ops(const char *name)
{
	unsigned long flags;
	struct list_head *ptr;
	struct ieee80211_crypto_alg *found_alg = NULL;

	if (hcrypt == NULL)
		return NULL;

	spin_lock_irqsave(&hcrypt->lock, flags);
	for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
		struct ieee80211_crypto_alg *alg =
			(struct ieee80211_crypto_alg *) ptr;
		if (strcmp(alg->ops->name, name) == 0) {
			found_alg = alg;
			break;
		}
	}
	spin_unlock_irqrestore(&hcrypt->lock, flags);

	if (found_alg)
		return found_alg->ops;
	else
		return NULL;
}


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,
	.encrypt_mpdu		= NULL,
	.decrypt_mpdu		= NULL,
	.encrypt_msdu		= NULL,
	.decrypt_msdu		= NULL,
	.set_key		= NULL,
	.get_key		= NULL,
	.extra_prefix_len	= 0,
	.extra_postfix_len	= 0,
	.owner			= THIS_MODULE,
};


static int __init ieee80211_crypto_init(void)
{
	int ret = -ENOMEM;

	hcrypt = kmalloc(sizeof(*hcrypt), GFP_KERNEL);
	if (!hcrypt)
		goto out;

	memset(hcrypt, 0, sizeof(*hcrypt));
	INIT_LIST_HEAD(&hcrypt->algs);
	spin_lock_init(&hcrypt->lock);

	ret = ieee80211_register_crypto_ops(&ieee80211_crypt_null);
	if (ret < 0) {
		kfree(hcrypt);
		hcrypt = NULL;
	}
out:
	return ret;
}


static void __exit ieee80211_crypto_deinit(void)
{
	struct list_head *ptr, *n;

	if (hcrypt == NULL)
		return;

	for (ptr = hcrypt->algs.next, n = ptr->next; ptr != &hcrypt->algs;
	     ptr = n, n = ptr->next) {
		struct ieee80211_crypto_alg *alg =
			(struct ieee80211_crypto_alg *) ptr;
		list_del(ptr);
		printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
		       "'%s' (deinit)\n", alg->ops->name);
		kfree(alg);
	}

	kfree(hcrypt);
}

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

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);