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 
32 MODULE_DESCRIPTION(DRV_DESCRIPTION);
33 MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
34 MODULE_LICENSE("GPL");
35 
36 struct lib80211_crypto_alg {
37 	struct list_head list;
38 	struct lib80211_crypto_ops *ops;
39 };
40 
41 static LIST_HEAD(lib80211_crypto_algs);
42 static DEFINE_SPINLOCK(lib80211_crypto_lock);
43 
print_ssid(char * buf,const char * ssid,u8 ssid_len)44 const char *print_ssid(char *buf, const char *ssid, u8 ssid_len)
45 {
46 	const char *s = ssid;
47 	char *d = buf;
48 
49 	ssid_len = min_t(u8, ssid_len, IEEE80211_MAX_SSID_LEN);
50 	while (ssid_len--) {
51 		if (isprint(*s)) {
52 			*d++ = *s++;
53 			continue;
54 		}
55 
56 		*d++ = '\\';
57 		if (*s == '\0')
58 			*d++ = '0';
59 		else if (*s == '\n')
60 			*d++ = 'n';
61 		else if (*s == '\r')
62 			*d++ = 'r';
63 		else if (*s == '\t')
64 			*d++ = 't';
65 		else if (*s == '\\')
66 			*d++ = '\\';
67 		else
68 			d += snprintf(d, 3, "%03o", *s);
69 		s++;
70 	}
71 	*d = '\0';
72 	return buf;
73 }
74 EXPORT_SYMBOL(print_ssid);
75 
lib80211_crypt_info_init(struct lib80211_crypt_info * info,char * name,spinlock_t * lock)76 int lib80211_crypt_info_init(struct lib80211_crypt_info *info, char *name,
77 				spinlock_t *lock)
78 {
79 	memset(info, 0, sizeof(*info));
80 
81 	info->name = name;
82 	info->lock = lock;
83 
84 	INIT_LIST_HEAD(&info->crypt_deinit_list);
85 	setup_timer(&info->crypt_deinit_timer, lib80211_crypt_deinit_handler,
86 			(unsigned long)info);
87 
88 	return 0;
89 }
90 EXPORT_SYMBOL(lib80211_crypt_info_init);
91 
lib80211_crypt_info_free(struct lib80211_crypt_info * info)92 void lib80211_crypt_info_free(struct lib80211_crypt_info *info)
93 {
94 	int i;
95 
96         lib80211_crypt_quiescing(info);
97         del_timer_sync(&info->crypt_deinit_timer);
98         lib80211_crypt_deinit_entries(info, 1);
99 
100         for (i = 0; i < NUM_WEP_KEYS; i++) {
101                 struct lib80211_crypt_data *crypt = info->crypt[i];
102                 if (crypt) {
103                         if (crypt->ops) {
104                                 crypt->ops->deinit(crypt->priv);
105                                 module_put(crypt->ops->owner);
106                         }
107                         kfree(crypt);
108                         info->crypt[i] = NULL;
109                 }
110         }
111 }
112 EXPORT_SYMBOL(lib80211_crypt_info_free);
113 
lib80211_crypt_deinit_entries(struct lib80211_crypt_info * info,int force)114 void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info, int force)
115 {
116 	struct lib80211_crypt_data *entry, *next;
117 	unsigned long flags;
118 
119 	spin_lock_irqsave(info->lock, flags);
120 	list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
121 		if (atomic_read(&entry->refcnt) != 0 && !force)
122 			continue;
123 
124 		list_del(&entry->list);
125 
126 		if (entry->ops) {
127 			entry->ops->deinit(entry->priv);
128 			module_put(entry->ops->owner);
129 		}
130 		kfree(entry);
131 	}
132 	spin_unlock_irqrestore(info->lock, flags);
133 }
134 EXPORT_SYMBOL(lib80211_crypt_deinit_entries);
135 
136 /* After this, crypt_deinit_list won't accept new members */
lib80211_crypt_quiescing(struct lib80211_crypt_info * info)137 void lib80211_crypt_quiescing(struct lib80211_crypt_info *info)
138 {
139 	unsigned long flags;
140 
141 	spin_lock_irqsave(info->lock, flags);
142 	info->crypt_quiesced = 1;
143 	spin_unlock_irqrestore(info->lock, flags);
144 }
145 EXPORT_SYMBOL(lib80211_crypt_quiescing);
146 
lib80211_crypt_deinit_handler(unsigned long data)147 void lib80211_crypt_deinit_handler(unsigned long data)
148 {
149 	struct lib80211_crypt_info *info = (struct lib80211_crypt_info *)data;
150 	unsigned long flags;
151 
152 	lib80211_crypt_deinit_entries(info, 0);
153 
154 	spin_lock_irqsave(info->lock, flags);
155 	if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
156 		printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
157 		       "deletion list\n", info->name);
158 		info->crypt_deinit_timer.expires = jiffies + HZ;
159 		add_timer(&info->crypt_deinit_timer);
160 	}
161 	spin_unlock_irqrestore(info->lock, flags);
162 }
163 EXPORT_SYMBOL(lib80211_crypt_deinit_handler);
164 
lib80211_crypt_delayed_deinit(struct lib80211_crypt_info * info,struct lib80211_crypt_data ** crypt)165 void lib80211_crypt_delayed_deinit(struct lib80211_crypt_info *info,
166 				    struct lib80211_crypt_data **crypt)
167 {
168 	struct lib80211_crypt_data *tmp;
169 	unsigned long flags;
170 
171 	if (*crypt == NULL)
172 		return;
173 
174 	tmp = *crypt;
175 	*crypt = NULL;
176 
177 	/* must not run ops->deinit() while there may be pending encrypt or
178 	 * decrypt operations. Use a list of delayed deinits to avoid needing
179 	 * locking. */
180 
181 	spin_lock_irqsave(info->lock, flags);
182 	if (!info->crypt_quiesced) {
183 		list_add(&tmp->list, &info->crypt_deinit_list);
184 		if (!timer_pending(&info->crypt_deinit_timer)) {
185 			info->crypt_deinit_timer.expires = jiffies + HZ;
186 			add_timer(&info->crypt_deinit_timer);
187 		}
188 	}
189 	spin_unlock_irqrestore(info->lock, flags);
190 }
191 EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
192 
lib80211_register_crypto_ops(struct lib80211_crypto_ops * ops)193 int lib80211_register_crypto_ops(struct lib80211_crypto_ops *ops)
194 {
195 	unsigned long flags;
196 	struct lib80211_crypto_alg *alg;
197 
198 	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
199 	if (alg == NULL)
200 		return -ENOMEM;
201 
202 	alg->ops = ops;
203 
204 	spin_lock_irqsave(&lib80211_crypto_lock, flags);
205 	list_add(&alg->list, &lib80211_crypto_algs);
206 	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
207 
208 	printk(KERN_DEBUG "lib80211_crypt: registered algorithm '%s'\n",
209 	       ops->name);
210 
211 	return 0;
212 }
213 EXPORT_SYMBOL(lib80211_register_crypto_ops);
214 
lib80211_unregister_crypto_ops(struct lib80211_crypto_ops * ops)215 int lib80211_unregister_crypto_ops(struct lib80211_crypto_ops *ops)
216 {
217 	struct lib80211_crypto_alg *alg;
218 	unsigned long flags;
219 
220 	spin_lock_irqsave(&lib80211_crypto_lock, flags);
221 	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
222 		if (alg->ops == ops)
223 			goto found;
224 	}
225 	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
226 	return -EINVAL;
227 
228       found:
229 	printk(KERN_DEBUG "lib80211_crypt: unregistered algorithm '%s'\n",
230 	       ops->name);
231 	list_del(&alg->list);
232 	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
233 	kfree(alg);
234 	return 0;
235 }
236 EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
237 
lib80211_get_crypto_ops(const char * name)238 struct lib80211_crypto_ops *lib80211_get_crypto_ops(const char *name)
239 {
240 	struct lib80211_crypto_alg *alg;
241 	unsigned long flags;
242 
243 	spin_lock_irqsave(&lib80211_crypto_lock, flags);
244 	list_for_each_entry(alg, &lib80211_crypto_algs, list) {
245 		if (strcmp(alg->ops->name, name) == 0)
246 			goto found;
247 	}
248 	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
249 	return NULL;
250 
251       found:
252 	spin_unlock_irqrestore(&lib80211_crypto_lock, flags);
253 	return alg->ops;
254 }
255 EXPORT_SYMBOL(lib80211_get_crypto_ops);
256 
lib80211_crypt_null_init(int keyidx)257 static void *lib80211_crypt_null_init(int keyidx)
258 {
259 	return (void *)1;
260 }
261 
lib80211_crypt_null_deinit(void * priv)262 static void lib80211_crypt_null_deinit(void *priv)
263 {
264 }
265 
266 static struct lib80211_crypto_ops lib80211_crypt_null = {
267 	.name = "NULL",
268 	.init = lib80211_crypt_null_init,
269 	.deinit = lib80211_crypt_null_deinit,
270 	.owner = THIS_MODULE,
271 };
272 
lib80211_init(void)273 static int __init lib80211_init(void)
274 {
275 	pr_info(DRV_DESCRIPTION "\n");
276 	return lib80211_register_crypto_ops(&lib80211_crypt_null);
277 }
278 
lib80211_exit(void)279 static void __exit lib80211_exit(void)
280 {
281 	lib80211_unregister_crypto_ops(&lib80211_crypt_null);
282 	BUG_ON(!list_empty(&lib80211_crypto_algs));
283 }
284 
285 module_init(lib80211_init);
286 module_exit(lib80211_exit);
287