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
31MODULE_DESCRIPTION(DRV_DESCRIPTION);
32MODULE_AUTHOR("John W. Linville <linville@tuxdriver.com>");
33MODULE_LICENSE("GPL");
34
35struct lib80211_crypto_alg {
36	struct list_head list;
37	struct lib80211_crypto_ops *ops;
38};
39
40static LIST_HEAD(lib80211_crypto_algs);
41static DEFINE_SPINLOCK(lib80211_crypto_lock);
42
43static void lib80211_crypt_deinit_entries(struct lib80211_crypt_info *info,
44					  int force);
45static void lib80211_crypt_quiescing(struct lib80211_crypt_info *info);
46static void lib80211_crypt_deinit_handler(struct timer_list *t);
47
48int 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}
62EXPORT_SYMBOL(lib80211_crypt_info_init);
63
64void 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}
84EXPORT_SYMBOL(lib80211_crypt_info_free);
85
86static 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 */
109static 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
118static 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
136void 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}
162EXPORT_SYMBOL(lib80211_crypt_delayed_deinit);
163
164int 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}
184EXPORT_SYMBOL(lib80211_register_crypto_ops);
185
186int 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}
207EXPORT_SYMBOL(lib80211_unregister_crypto_ops);
208
209struct 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}
226EXPORT_SYMBOL(lib80211_get_crypto_ops);
227
228static void *lib80211_crypt_null_init(int keyidx)
229{
230	return (void *)1;
231}
232
233static void lib80211_crypt_null_deinit(void *priv)
234{
235}
236
237static 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
244static int __init lib80211_init(void)
245{
246	pr_info(DRV_DESCRIPTION "\n");
247	return lib80211_register_crypto_ops(&lib80211_crypt_null);
248}
249
250static void __exit lib80211_exit(void)
251{
252	lib80211_unregister_crypto_ops(&lib80211_crypt_null);
253	BUG_ON(!list_empty(&lib80211_crypto_algs));
254}
255
256module_init(lib80211_init);
257module_exit(lib80211_exit);
258