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/module.h>
15 #include <linux/init.h>
16 #include <linux/slab.h>
17 #include <linux/string.h>
18 #include <linux/errno.h>
19 
20 #include "rtllib.h"
21 
22 struct rtllib_crypto_alg {
23 	struct list_head list;
24 	struct lib80211_crypto_ops *ops;
25 };
26 
27 
28 struct rtllib_crypto {
29 	struct list_head algs;
30 	spinlock_t lock;
31 };
32 
33 static struct rtllib_crypto *hcrypt;
34 
rtllib_crypt_deinit_entries(struct lib80211_crypt_info * info,int force)35 void rtllib_crypt_deinit_entries(struct lib80211_crypt_info *info,
36 					   int force)
37 {
38 	struct list_head *ptr, *n;
39 	struct lib80211_crypt_data *entry;
40 
41 	for (ptr = info->crypt_deinit_list.next, n = ptr->next;
42 	     ptr != &info->crypt_deinit_list; ptr = n, n = ptr->next) {
43 		entry = list_entry(ptr, struct lib80211_crypt_data, list);
44 
45 		if (atomic_read(&entry->refcnt) != 0 && !force)
46 			continue;
47 
48 		list_del(ptr);
49 
50 		if (entry->ops)
51 			entry->ops->deinit(entry->priv);
52 		kfree(entry);
53 	}
54 }
55 EXPORT_SYMBOL(rtllib_crypt_deinit_entries);
56 
rtllib_crypt_deinit_handler(unsigned long data)57 void rtllib_crypt_deinit_handler(unsigned long data)
58 {
59 	struct lib80211_crypt_info *info = (struct lib80211_crypt_info *)data;
60 	unsigned long flags;
61 
62 	spin_lock_irqsave(info->lock, flags);
63 	rtllib_crypt_deinit_entries(info, 0);
64 	if (!list_empty(&info->crypt_deinit_list)) {
65 		printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
66 		       "deletion list\n", info->name);
67 		info->crypt_deinit_timer.expires = jiffies + HZ;
68 		add_timer(&info->crypt_deinit_timer);
69 	}
70 	spin_unlock_irqrestore(info->lock, flags);
71 
72 }
73 EXPORT_SYMBOL(rtllib_crypt_deinit_handler);
74 
rtllib_crypt_delayed_deinit(struct lib80211_crypt_info * info,struct lib80211_crypt_data ** crypt)75 void rtllib_crypt_delayed_deinit(struct lib80211_crypt_info *info,
76 				 struct lib80211_crypt_data **crypt)
77 {
78 	struct lib80211_crypt_data *tmp;
79 	unsigned long flags;
80 
81 	if (*crypt == NULL)
82 		return;
83 
84 	tmp = *crypt;
85 	*crypt = NULL;
86 
87 	/* must not run ops->deinit() while there may be pending encrypt or
88 	 * decrypt operations. Use a list of delayed deinits to avoid needing
89 	 * locking. */
90 
91 	spin_lock_irqsave(info->lock, flags);
92 	list_add(&tmp->list, &info->crypt_deinit_list);
93 	if (!timer_pending(&info->crypt_deinit_timer)) {
94 		info->crypt_deinit_timer.expires = jiffies + HZ;
95 		add_timer(&info->crypt_deinit_timer);
96 	}
97 	spin_unlock_irqrestore(info->lock, flags);
98 }
99 EXPORT_SYMBOL(rtllib_crypt_delayed_deinit);
100 
rtllib_register_crypto_ops(struct lib80211_crypto_ops * ops)101 int rtllib_register_crypto_ops(struct lib80211_crypto_ops *ops)
102 {
103 	unsigned long flags;
104 	struct rtllib_crypto_alg *alg;
105 
106 	if (hcrypt == NULL)
107 		return -1;
108 
109 	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
110 	if (alg == NULL)
111 		return -ENOMEM;
112 
113 	alg->ops = ops;
114 
115 	spin_lock_irqsave(&hcrypt->lock, flags);
116 	list_add(&alg->list, &hcrypt->algs);
117 	spin_unlock_irqrestore(&hcrypt->lock, flags);
118 
119 	printk(KERN_DEBUG "rtllib_crypt: registered algorithm '%s'\n",
120 	       ops->name);
121 
122 	return 0;
123 }
124 EXPORT_SYMBOL(rtllib_register_crypto_ops);
125 
rtllib_unregister_crypto_ops(struct lib80211_crypto_ops * ops)126 int rtllib_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
127 {
128 	unsigned long flags;
129 	struct list_head *ptr;
130 	struct rtllib_crypto_alg *del_alg = NULL;
131 
132 	if (hcrypt == NULL)
133 		return -1;
134 
135 	spin_lock_irqsave(&hcrypt->lock, flags);
136 	for (ptr = hcrypt->algs.next; ptr != &hcrypt->algs; ptr = ptr->next) {
137 		struct rtllib_crypto_alg *alg =
138 			(struct rtllib_crypto_alg *) ptr;
139 		if (alg->ops == ops) {
140 			list_del(&alg->list);
141 			del_alg = alg;
142 			break;
143 		}
144 	}
145 	spin_unlock_irqrestore(&hcrypt->lock, flags);
146 
147 	if (del_alg) {
148 		printk(KERN_DEBUG "rtllib_crypt: unregistered algorithm "
149 		       "'%s'\n", ops->name);
150 		kfree(del_alg);
151 	}
152 
153 	return del_alg ? 0 : -1;
154 }
155 EXPORT_SYMBOL(rtllib_unregister_crypto_ops);
156 
157 
rtllib_get_crypto_ops(const char * name)158 struct lib80211_crypto_ops *rtllib_get_crypto_ops(const char *name)
159 {
160 	unsigned long flags;
161 	struct list_head *ptr;
162 	struct rtllib_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 rtllib_crypto_alg *alg =
170 			(struct rtllib_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 EXPORT_SYMBOL(rtllib_get_crypto_ops);
184 
185 
rtllib_crypt_null_init(int keyidx)186 static void * rtllib_crypt_null_init(int keyidx) { return (void *) 1; }
rtllib_crypt_null_deinit(void * priv)187 static void rtllib_crypt_null_deinit(void *priv) {}
188 
189 static struct lib80211_crypto_ops rtllib_crypt_null = {
190 	.name			= "NULL",
191 	.init			= rtllib_crypt_null_init,
192 	.deinit			= rtllib_crypt_null_deinit,
193 	.encrypt_mpdu		= NULL,
194 	.decrypt_mpdu		= NULL,
195 	.encrypt_msdu		= NULL,
196 	.decrypt_msdu		= NULL,
197 	.set_key		= NULL,
198 	.get_key		= NULL,
199 	.extra_mpdu_prefix_len	= 0,
200 	.extra_mpdu_postfix_len	= 0,
201 	.extra_msdu_prefix_len	= 0,
202 	.extra_msdu_postfix_len	= 0,
203 	.owner			= THIS_MODULE,
204 };
205 
206 
rtllib_crypto_init(void)207 int __init rtllib_crypto_init(void)
208 {
209 	int ret = -ENOMEM;
210 
211 	hcrypt = kzalloc(sizeof(*hcrypt), GFP_KERNEL);
212 	if (!hcrypt)
213 		goto out;
214 
215 	INIT_LIST_HEAD(&hcrypt->algs);
216 	spin_lock_init(&hcrypt->lock);
217 
218 	ret = lib80211_register_crypto_ops(&rtllib_crypt_null);
219 	if (ret < 0) {
220 		kfree(hcrypt);
221 		hcrypt = NULL;
222 	}
223 out:
224 	return ret;
225 }
226 
227 
rtllib_crypto_deinit(void)228 void __exit rtllib_crypto_deinit(void)
229 {
230 	struct list_head *ptr, *n;
231 
232 	if (hcrypt == NULL)
233 		return;
234 
235 	for (ptr = hcrypt->algs.next, n = ptr->next; ptr != &hcrypt->algs;
236 	     ptr = n, n = ptr->next) {
237 		struct rtllib_crypto_alg *alg =
238 			(struct rtllib_crypto_alg *) ptr;
239 		list_del(ptr);
240 		printk(KERN_DEBUG "rtllib_crypt: unregistered algorithm "
241 		       "'%s' (deinit)\n", alg->ops->name);
242 		kfree(alg);
243 	}
244 
245 	kfree(hcrypt);
246 }
247 
248 module_init(rtllib_crypto_init);
249 module_exit(rtllib_crypto_deinit);
250 
251 MODULE_LICENSE("GPL");
252