xref: /openbmc/linux/net/wireless/lib80211.c (revision 7a010c3c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * lib80211 -- common bits for IEEE802.11 drivers
4  *
5  * Copyright(c) 2008 John W. Linville <linville@tuxdriver.com>
6  *
7  * Portions copied from old ieee80211 component, w/ original copyright
8  * notices below:
9  *
10  * Host AP crypto routines
11  *
12  * Copyright (c) 2002-2003, Jouni Malinen <j@w1.fi>
13  * Portions Copyright (C) 2004, Intel Corporation <jketreno@linux.intel.com>
14  *
15  */
16 
17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 
19 #include <linux/module.h>
20 #include <linux/ctype.h>
21 #include <linux/ieee80211.h>
22 #include <linux/errno.h>
23 #include <linux/init.h>
24 #include <linux/slab.h>
25 #include <linux/string.h>
26 
27 #include <net/lib80211.h>
28 
29 #define DRV_DESCRIPTION	"common routines for IEEE802.11 drivers"
30 
31 MODULE_DESCRIPTION(DRV_DESCRIPTION);
32 MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
33 MODULE_LICENSE("GPL");
34 
35 struct lib80211_crypto_alg {
36 	struct list_head list;
37 	struct lib80211_crypto_ops *ops;
38 };
39 
40 static LIST_HEAD(lib80211_crypto_algs);
41 static DEFINE_SPINLOCK(lib80211_crypto_lock);
42 
43 static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
44 					  int force);
45 static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info);
46 static void lib80211_crypt_deinit_handler(struct timer_list *t);
47 
48 int lib80211_crypt_info_init(struct lib80211_crypt_info *info, char *name,
49 				spinlock_t *lock)
50 {
51 	memset(info, 0, sizeof(*info));
52 
53 	info->name = name;
54 	info->lock = lock;
55 
56 	INIT_LIST_HEAD(&info->crypt_deinit_list);
57 	timer_setup(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
58 		    0);
59 
60 	return 0;
61 }
62 EXPORT_SYMBOL(lib80211_crypt_info_init);
63 
64 void lib80211_crypt_info_free(struct lib80211_crypt_info *info)
65 {
66 	int i;
67 
68         lib80211_crypt_quiescing(info);
69         del_timer_sync(&info->crypt_deinit_timer);
70         lib80211_crypt_deinit_entries(info, 1);
71 
72         for (i = 0; i < NUM_WEP_KEYS; i++) {
73                 struct lib80211_crypt_data *crypt = info->crypt[i];
74                 if (crypt) {
75                         if (crypt->ops) {
76                                 crypt->ops->deinit(crypt->priv);
77                                 module_put(crypt->ops->owner);
78                         }
79                         kfree(crypt);
80                         info->crypt[i] = NULL;
81                 }
82         }
83 }
84 EXPORT_SYMBOL(lib80211_crypt_info_free);
85 
86 static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
87 					  int force)
88 {
89 	struct lib80211_crypt_data *entry, *next;
90 	unsigned long flags;
91 
92 	spin_lock_irqsave(info->lock, flags);
93 	list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
94 		if (atomic_read(&entry->refcnt) != 0 && !force)
95 			continue;
96 
97 		list_del(&entry->list);
98 
99 		if (entry->ops) {
100 			entry->ops->deinit(entry->priv);
101 			module_put(entry->ops->owner);
102 		}
103 		kfree(entry);
104 	}
105 	spin_unlock_irqrestore(info->lock, flags);
106 }
107 
108 /* After this, crypt_deinit_list won't accept new members */
109 static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info)
110 {
111 	unsigned long flags;
112 
113 	spin_lock_irqsave(info->lock, flags);
114 	info->crypt_quiesced = 1;
115 	spin_unlock_irqrestore(info->lock, flags);
116 }
117 
118 static void lib80211_crypt_deinit_handler(struct timer_list *t)
119 {
120 	struct lib80211_crypt_info *info = from_timer(info, t,
121 						      crypt_deinit_timer);
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 
136 void 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 }
162 EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
163 
164 int 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 }
184 EXPORT_SYMBOL(lib80211_register_crypto_ops);
185 
186 int 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 }
207 EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
208 
209 struct 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 }
226 EXPORT_SYMBOL(lib80211_get_crypto_ops);
227 
228 static void *lib80211_crypt_null_init(int keyidx)
229 {
230 	return (void *)1;
231 }
232 
233 static void lib80211_crypt_null_deinit(void *priv)
234 {
235 }
236 
237 static 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 
244 static int __init lib80211_init(void)
245 {
246 	pr_info(DRV_DESCRIPTION "\n");
247 	return lib80211_register_crypto_ops(&lib80211_crypt_null);
248 }
249 
250 static void __exit lib80211_exit(void)
251 {
252 	lib80211_unregister_crypto_ops(&lib80211_crypt_null);
253 	BUG_ON(!list_empty(&lib80211_crypto_algs));
254 }
255 
256 module_init(lib80211_init);
257 module_exit(lib80211_exit);
258