xref: /linux/drivers/net/wireless/intel/ipw2x00/libipw_crypto.c (revision 3ba84ac69b53e6ee07c31d54554e00793d7b144f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * libipw -- common bits for IPW 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 #include "libipw.h"
27 
28 struct libipw_crypto_alg {
29 	struct list_head list;
30 	const struct libipw_crypto_ops *ops;
31 };
32 
33 static LIST_HEAD(libipw_crypto_algs);
34 static DEFINE_SPINLOCK(libipw_crypto_lock);
35 
36 static void libipw_crypt_deinit_entries(struct libipw_crypt_info *info,
37 					  int force);
38 static void libipw_crypt_quiescing(struct libipw_crypt_info *info);
39 static void libipw_crypt_deinit_handler(struct timer_list *t);
40 
41 int libipw_crypt_info_init(struct libipw_crypt_info *info, char *name,
42 				spinlock_t *lock)
43 {
44 	memset(info, 0, sizeof(*info));
45 
46 	info->name = name;
47 	info->lock = lock;
48 
49 	INIT_LIST_HEAD(&info->crypt_deinit_list);
50 	timer_setup(&info->crypt_deinit_timer, libipw_crypt_deinit_handler,
51 		    0);
52 
53 	return 0;
54 }
55 EXPORT_SYMBOL(libipw_crypt_info_init);
56 
57 void libipw_crypt_info_free(struct libipw_crypt_info *info)
58 {
59 	int i;
60 
61         libipw_crypt_quiescing(info);
62         del_timer_sync(&info->crypt_deinit_timer);
63         libipw_crypt_deinit_entries(info, 1);
64 
65         for (i = 0; i < NUM_WEP_KEYS; i++) {
66                 struct libipw_crypt_data *crypt = info->crypt[i];
67                 if (crypt) {
68                         if (crypt->ops) {
69                                 crypt->ops->deinit(crypt->priv);
70                                 module_put(crypt->ops->owner);
71                         }
72                         kfree(crypt);
73                         info->crypt[i] = NULL;
74                 }
75         }
76 }
77 EXPORT_SYMBOL(libipw_crypt_info_free);
78 
79 static void libipw_crypt_deinit_entries(struct libipw_crypt_info *info,
80 					int force)
81 {
82 	struct libipw_crypt_data *entry, *next;
83 	unsigned long flags;
84 
85 	spin_lock_irqsave(info->lock, flags);
86 	list_for_each_entry_safe(entry, next, &info->crypt_deinit_list, list) {
87 		if (atomic_read(&entry->refcnt) != 0 && !force)
88 			continue;
89 
90 		list_del(&entry->list);
91 
92 		if (entry->ops) {
93 			entry->ops->deinit(entry->priv);
94 			module_put(entry->ops->owner);
95 		}
96 		kfree(entry);
97 	}
98 	spin_unlock_irqrestore(info->lock, flags);
99 }
100 
101 /* After this, crypt_deinit_list won't accept new members */
102 static void libipw_crypt_quiescing(struct libipw_crypt_info *info)
103 {
104 	unsigned long flags;
105 
106 	spin_lock_irqsave(info->lock, flags);
107 	info->crypt_quiesced = 1;
108 	spin_unlock_irqrestore(info->lock, flags);
109 }
110 
111 static void libipw_crypt_deinit_handler(struct timer_list *t)
112 {
113 	struct libipw_crypt_info *info = from_timer(info, t,
114 						    crypt_deinit_timer);
115 	unsigned long flags;
116 
117 	libipw_crypt_deinit_entries(info, 0);
118 
119 	spin_lock_irqsave(info->lock, flags);
120 	if (!list_empty(&info->crypt_deinit_list) && !info->crypt_quiesced) {
121 		printk(KERN_DEBUG "%s: entries remaining in delayed crypt "
122 		       "deletion list\n", info->name);
123 		info->crypt_deinit_timer.expires = jiffies + HZ;
124 		add_timer(&info->crypt_deinit_timer);
125 	}
126 	spin_unlock_irqrestore(info->lock, flags);
127 }
128 
129 void libipw_crypt_delayed_deinit(struct libipw_crypt_info *info,
130 				 struct libipw_crypt_data **crypt)
131 {
132 	struct libipw_crypt_data *tmp;
133 	unsigned long flags;
134 
135 	if (*crypt == NULL)
136 		return;
137 
138 	tmp = *crypt;
139 	*crypt = NULL;
140 
141 	/* must not run ops->deinit() while there may be pending encrypt or
142 	 * decrypt operations. Use a list of delayed deinits to avoid needing
143 	 * locking. */
144 
145 	spin_lock_irqsave(info->lock, flags);
146 	if (!info->crypt_quiesced) {
147 		list_add(&tmp->list, &info->crypt_deinit_list);
148 		if (!timer_pending(&info->crypt_deinit_timer)) {
149 			info->crypt_deinit_timer.expires = jiffies + HZ;
150 			add_timer(&info->crypt_deinit_timer);
151 		}
152 	}
153 	spin_unlock_irqrestore(info->lock, flags);
154 }
155 EXPORT_SYMBOL(libipw_crypt_delayed_deinit);
156 
157 int libipw_register_crypto_ops(const struct libipw_crypto_ops *ops)
158 {
159 	unsigned long flags;
160 	struct libipw_crypto_alg *alg;
161 
162 	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
163 	if (alg == NULL)
164 		return -ENOMEM;
165 
166 	alg->ops = ops;
167 
168 	spin_lock_irqsave(&libipw_crypto_lock, flags);
169 	list_add(&alg->list, &libipw_crypto_algs);
170 	spin_unlock_irqrestore(&libipw_crypto_lock, flags);
171 
172 	printk(KERN_DEBUG "libipw_crypt: registered algorithm '%s'\n",
173 	       ops->name);
174 
175 	return 0;
176 }
177 EXPORT_SYMBOL(libipw_register_crypto_ops);
178 
179 int libipw_unregister_crypto_ops(const struct libipw_crypto_ops *ops)
180 {
181 	struct libipw_crypto_alg *alg;
182 	unsigned long flags;
183 
184 	spin_lock_irqsave(&libipw_crypto_lock, flags);
185 	list_for_each_entry(alg, &libipw_crypto_algs, list) {
186 		if (alg->ops == ops)
187 			goto found;
188 	}
189 	spin_unlock_irqrestore(&libipw_crypto_lock, flags);
190 	return -EINVAL;
191 
192       found:
193 	printk(KERN_DEBUG "libipw_crypt: unregistered algorithm '%s'\n",
194 	       ops->name);
195 	list_del(&alg->list);
196 	spin_unlock_irqrestore(&libipw_crypto_lock, flags);
197 	kfree(alg);
198 	return 0;
199 }
200 EXPORT_SYMBOL(libipw_unregister_crypto_ops);
201 
202 const struct libipw_crypto_ops *libipw_get_crypto_ops(const char *name)
203 {
204 	struct libipw_crypto_alg *alg;
205 	unsigned long flags;
206 
207 	spin_lock_irqsave(&libipw_crypto_lock, flags);
208 	list_for_each_entry(alg, &libipw_crypto_algs, list) {
209 		if (strcmp(alg->ops->name, name) == 0)
210 			goto found;
211 	}
212 	spin_unlock_irqrestore(&libipw_crypto_lock, flags);
213 	return NULL;
214 
215       found:
216 	spin_unlock_irqrestore(&libipw_crypto_lock, flags);
217 	return alg->ops;
218 }
219 EXPORT_SYMBOL(libipw_get_crypto_ops);
220 
221 static void *libipw_crypt_null_init(int keyidx)
222 {
223 	return (void *)1;
224 }
225 
226 static void libipw_crypt_null_deinit(void *priv)
227 {
228 }
229 
230 static const struct libipw_crypto_ops libipw_crypt_null = {
231 	.name = "NULL",
232 	.init = libipw_crypt_null_init,
233 	.deinit = libipw_crypt_null_deinit,
234 	.owner = THIS_MODULE,
235 };
236 
237 int __init libipw_crypto_init(void)
238 {
239 	return libipw_register_crypto_ops(&libipw_crypt_null);
240 }
241 
242 void libipw_crypto_exit(void)
243 {
244 	libipw_unregister_crypto_ops(&libipw_crypt_null);
245 	BUG_ON(!list_empty(&libipw_crypto_algs));
246 }
247