1/*
2 * Host AP crypto routines
3 *
4 * Copyright (c) 2002-2003, Jouni Malinen <jkmaline@cc.hut.fi>
5 * Portions Copyright (C) 2004, Intel Corporation <jketreno@linux.intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation. See README and COPYING for
10 * more details.
11 *
12 */
13
14//#include <linux/config.h>
15#include <linux/module.h>
16#include <linux/init.h>
17#include <linux/slab.h>
18#include <asm/string.h>
19#include <asm/errno.h>
20
21#include "ieee80211.h"
22
23MODULE_AUTHOR("Jouni Malinen");
24MODULE_DESCRIPTION("HostAP crypto");
25MODULE_LICENSE("GPL");
26
27struct ieee80211_crypto_alg {
28	struct list_head list;
29	struct ieee80211_crypto_ops *ops;
30};
31
32
33struct ieee80211_crypto {
34	struct list_head algs;
35	spinlock_t lock;
36};
37
38static struct ieee80211_crypto *hcrypt;
39
40void ieee80211_crypt_deinit_entries(struct ieee80211_device *ieee,
41					   int force)
42{
43	struct list_head *ptr, *n;
44	struct ieee80211_crypt_data *entry;
45
46	for (ptr = ieee->crypt_deinit_list.next, n = ptr->next;
47	     ptr != &ieee->crypt_deinit_list; ptr = n, n = ptr->next) {
48		entry = list_entry(ptr, struct ieee80211_crypt_data, list);
49
50		if (atomic_read(&entry->refcnt) != 0 && !force)
51			continue;
52
53		list_del(ptr);
54
55		if (entry->ops)
56			entry->ops->deinit(entry->priv);
57		kfree(entry);
58	}
59}
60
61void ieee80211_crypt_deinit_handler(unsigned long data)
62{
63	struct ieee80211_device *ieee = (struct ieee80211_device *)data;
64	unsigned long flags;
65
66	spin_lock_irqsave(&ieee->lock, flags);
67	ieee80211_crypt_deinit_entries(ieee, 0);
68	if (!list_empty(&ieee->crypt_deinit_list)) {
69		printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
70		       "deletion list\n", ieee->dev->name);
71		ieee->crypt_deinit_timer.expires = jiffies + HZ;
72		add_timer(&ieee->crypt_deinit_timer);
73	}
74	spin_unlock_irqrestore(&ieee->lock, flags);
75
76}
77
78void ieee80211_crypt_delayed_deinit(struct ieee80211_device *ieee,
79				    struct ieee80211_crypt_data **crypt)
80{
81	struct ieee80211_crypt_data *tmp;
82	unsigned long flags;
83
84	if (*crypt == NULL)
85		return;
86
87	tmp = *crypt;
88	*crypt = NULL;
89
90	/* must not run ops->deinit() while there may be pending encrypt or
91	 * decrypt operations. Use a list of delayed deinits to avoid needing
92	 * locking. */
93
94	spin_lock_irqsave(&ieee->lock, flags);
95	list_add(&tmp->list, &ieee->crypt_deinit_list);
96	if (!timer_pending(&ieee->crypt_deinit_timer)) {
97		ieee->crypt_deinit_timer.expires = jiffies + HZ;
98		add_timer(&ieee->crypt_deinit_timer);
99	}
100	spin_unlock_irqrestore(&ieee->lock, flags);
101}
102
103int ieee80211_register_crypto_ops(struct ieee80211_crypto_ops *ops)
104{
105	unsigned long flags;
106	struct ieee80211_crypto_alg *alg;
107
108	if (hcrypt == NULL)
109		return -1;
110
111	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
112	if (alg == NULL)
113		return -ENOMEM;
114
115	alg->ops = ops;
116
117	spin_lock_irqsave(&hcrypt->lock, flags);
118	list_add(&alg->list, &hcrypt->algs);
119	spin_unlock_irqrestore(&hcrypt->lock, flags);
120
121	printk(KERN_DEBUG "ieee80211_crypt: registered algorithm '%s'\n",
122	       ops->name);
123
124	return 0;
125}
126
127int ieee80211_unregister_crypto_ops(struct ieee80211_crypto_ops *ops)
128{
129	unsigned long flags;
130	struct list_head *ptr;
131	struct ieee80211_crypto_alg *del_alg = NULL;
132
133	if (hcrypt == NULL)
134		return -1;
135
136	spin_lock_irqsave(&hcrypt->lock, flags);
137	for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
138		struct ieee80211_crypto_alg *alg =
139			(struct ieee80211_crypto_alg *) ptr;
140		if (alg->ops == ops) {
141			list_del(&alg->list);
142			del_alg = alg;
143			break;
144		}
145	}
146	spin_unlock_irqrestore(&hcrypt->lock, flags);
147
148	if (del_alg) {
149		printk(KERN_DEBUG "ieee80211_crypt: unregistered algorithm "
150		       "'%s'\n", ops->name);
151		kfree(del_alg);
152	}
153
154	return del_alg ? 0 : -1;
155}
156
157
158struct ieee80211_crypto_ops * ieee80211_get_crypto_ops(const char *name)
159{
160	unsigned long flags;
161	struct list_head *ptr;
162	struct ieee80211_crypto_alg *found_alg = NULL;
163
164	if (hcrypt == NULL)
165		return NULL;
166
167	spin_lock_irqsave(&hcrypt->lock, flags);
168	for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
169		struct ieee80211_crypto_alg *alg =
170			(struct ieee80211_crypto_alg *) ptr;
171		if (strcmp(alg->ops->name, name) == 0) {
172			found_alg = alg;
173			break;
174		}
175	}
176	spin_unlock_irqrestore(&hcrypt->lock, flags);
177
178	if (found_alg)
179		return found_alg->ops;
180	else
181		return NULL;
182}
183
184
185static void * ieee80211_crypt_null_init(int keyidx) { return (void *) 1; }
186static void ieee80211_crypt_null_deinit(void *priv) {}
187
188static struct ieee80211_crypto_ops ieee80211_crypt_null = {
189	.name			= "NULL",
190	.init			= ieee80211_crypt_null_init,
191	.deinit			= ieee80211_crypt_null_deinit,
192	.encrypt_mpdu		= NULL,
193	.decrypt_mpdu		= NULL,
194	.encrypt_msdu		= NULL,
195	.decrypt_msdu		= NULL,
196	.set_key		= NULL,
197	.get_key		= NULL,
198	.extra_prefix_len	= 0,
199	.extra_postfix_len	= 0,
200	.owner			= THIS_MODULE,
201};
202
203
204int ieee80211_crypto_init(void)
205{
206	int ret = -ENOMEM;
207
208	hcrypt = kzalloc(sizeof(*hcrypt), GFP_KERNEL);
209	if (!hcrypt)
210		goto out;
211
212	INIT_LIST_HEAD(&hcrypt->algs);
213	spin_lock_init(&hcrypt->lock);
214
215	ret = ieee80211_register_crypto_ops(&ieee80211_crypt_null);
216	if (ret < 0) {
217		kfree(hcrypt);
218		hcrypt = NULL;
219	}
220out:
221	return ret;
222}
223
224
225void ieee80211_crypto_deinit(void)
226{
227	struct list_head *ptr, *n;
228	struct ieee80211_crypto_alg *alg = NULL;
229
230	if (hcrypt == NULL)
231		return;
232
233	list_for_each_safe(ptr, n, &hcrypt->algs) {
234		alg = list_entry(ptr, struct ieee80211_crypto_alg, list);
235		if (alg) {
236			list_del(ptr);
237			printk(KERN_DEBUG
238			       "ieee80211_crypt: unregistered algorithm '%s' (deinit)\n",
239			       alg->ops->name);
240			kfree(alg);
241		}
242	}
243	kfree(hcrypt);
244}
245