xref: /linux/net/ieee802154/core.c (revision 93d90ad708b8da6efc0e487b66111aa9db7f70c7)
1 /*
2  * Copyright (C) 2007, 2008, 2009 Siemens AG
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2
6  * as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  */
14 
15 #include <linux/slab.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/device.h>
19 
20 #include <net/cfg802154.h>
21 #include <net/rtnetlink.h>
22 
23 #include "ieee802154.h"
24 #include "nl802154.h"
25 #include "sysfs.h"
26 #include "core.h"
27 
28 /* RCU-protected (and RTNL for writers) */
29 LIST_HEAD(cfg802154_rdev_list);
30 int cfg802154_rdev_list_generation;
31 
32 static int wpan_phy_match(struct device *dev, const void *data)
33 {
34 	return !strcmp(dev_name(dev), (const char *)data);
35 }
36 
37 struct wpan_phy *wpan_phy_find(const char *str)
38 {
39 	struct device *dev;
40 
41 	if (WARN_ON(!str))
42 		return NULL;
43 
44 	dev = class_find_device(&wpan_phy_class, NULL, str, wpan_phy_match);
45 	if (!dev)
46 		return NULL;
47 
48 	return container_of(dev, struct wpan_phy, dev);
49 }
50 EXPORT_SYMBOL(wpan_phy_find);
51 
52 struct wpan_phy_iter_data {
53 	int (*fn)(struct wpan_phy *phy, void *data);
54 	void *data;
55 };
56 
57 static int wpan_phy_iter(struct device *dev, void *_data)
58 {
59 	struct wpan_phy_iter_data *wpid = _data;
60 	struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);
61 
62 	return wpid->fn(phy, wpid->data);
63 }
64 
65 int wpan_phy_for_each(int (*fn)(struct wpan_phy *phy, void *data),
66 		      void *data)
67 {
68 	struct wpan_phy_iter_data wpid = {
69 		.fn = fn,
70 		.data = data,
71 	};
72 
73 	return class_for_each_device(&wpan_phy_class, NULL,
74 			&wpid, wpan_phy_iter);
75 }
76 EXPORT_SYMBOL(wpan_phy_for_each);
77 
78 struct cfg802154_registered_device *
79 cfg802154_rdev_by_wpan_phy_idx(int wpan_phy_idx)
80 {
81 	struct cfg802154_registered_device *result = NULL, *rdev;
82 
83 	ASSERT_RTNL();
84 
85 	list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
86 		if (rdev->wpan_phy_idx == wpan_phy_idx) {
87 			result = rdev;
88 			break;
89 		}
90 	}
91 
92 	return result;
93 }
94 
95 struct wpan_phy *
96 wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size)
97 {
98 	static atomic_t wpan_phy_counter = ATOMIC_INIT(0);
99 	struct cfg802154_registered_device *rdev;
100 	size_t alloc_size;
101 
102 	alloc_size = sizeof(*rdev) + priv_size;
103 	rdev = kzalloc(alloc_size, GFP_KERNEL);
104 	if (!rdev)
105 		return NULL;
106 
107 	rdev->ops = ops;
108 
109 	rdev->wpan_phy_idx = atomic_inc_return(&wpan_phy_counter);
110 
111 	if (unlikely(rdev->wpan_phy_idx < 0)) {
112 		/* ugh, wrapped! */
113 		atomic_dec(&wpan_phy_counter);
114 		kfree(rdev);
115 		return NULL;
116 	}
117 
118 	/* atomic_inc_return makes it start at 1, make it start at 0 */
119 	rdev->wpan_phy_idx--;
120 
121 	mutex_init(&rdev->wpan_phy.pib_lock);
122 
123 	INIT_LIST_HEAD(&rdev->wpan_dev_list);
124 	device_initialize(&rdev->wpan_phy.dev);
125 	dev_set_name(&rdev->wpan_phy.dev, "wpan-phy%d", rdev->wpan_phy_idx);
126 
127 	rdev->wpan_phy.dev.class = &wpan_phy_class;
128 	rdev->wpan_phy.dev.platform_data = rdev;
129 
130 	init_waitqueue_head(&rdev->dev_wait);
131 
132 	return &rdev->wpan_phy;
133 }
134 EXPORT_SYMBOL(wpan_phy_new);
135 
136 int wpan_phy_register(struct wpan_phy *phy)
137 {
138 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
139 	int ret;
140 
141 	rtnl_lock();
142 	ret = device_add(&phy->dev);
143 	if (ret) {
144 		rtnl_unlock();
145 		return ret;
146 	}
147 
148 	list_add_rcu(&rdev->list, &cfg802154_rdev_list);
149 	cfg802154_rdev_list_generation++;
150 
151 	/* TODO phy registered lock */
152 	rtnl_unlock();
153 
154 	/* TODO nl802154 phy notify */
155 
156 	return 0;
157 }
158 EXPORT_SYMBOL(wpan_phy_register);
159 
160 void wpan_phy_unregister(struct wpan_phy *phy)
161 {
162 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
163 
164 	wait_event(rdev->dev_wait, ({
165 		int __count;
166 		rtnl_lock();
167 		__count = rdev->opencount;
168 		rtnl_unlock();
169 		__count == 0; }));
170 
171 	rtnl_lock();
172 	/* TODO nl802154 phy notify */
173 	/* TODO phy registered lock */
174 
175 	WARN_ON(!list_empty(&rdev->wpan_dev_list));
176 
177 	/* First remove the hardware from everywhere, this makes
178 	 * it impossible to find from userspace.
179 	 */
180 	list_del_rcu(&rdev->list);
181 	synchronize_rcu();
182 
183 	cfg802154_rdev_list_generation++;
184 
185 	device_del(&phy->dev);
186 
187 	rtnl_unlock();
188 }
189 EXPORT_SYMBOL(wpan_phy_unregister);
190 
191 void wpan_phy_free(struct wpan_phy *phy)
192 {
193 	put_device(&phy->dev);
194 }
195 EXPORT_SYMBOL(wpan_phy_free);
196 
197 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
198 {
199 	kfree(rdev);
200 }
201 
202 static void
203 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
204 			   int iftype, int num)
205 {
206 	ASSERT_RTNL();
207 
208 	rdev->num_running_ifaces += num;
209 }
210 
211 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
212 					  unsigned long state, void *ptr)
213 {
214 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
215 	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
216 	struct cfg802154_registered_device *rdev;
217 
218 	if (!wpan_dev)
219 		return NOTIFY_DONE;
220 
221 	rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
222 
223 	/* TODO WARN_ON unspec type */
224 
225 	switch (state) {
226 		/* TODO NETDEV_DEVTYPE */
227 	case NETDEV_REGISTER:
228 		wpan_dev->identifier = ++rdev->wpan_dev_id;
229 		list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
230 		rdev->devlist_generation++;
231 
232 		wpan_dev->netdev = dev;
233 		break;
234 	case NETDEV_DOWN:
235 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
236 
237 		rdev->opencount--;
238 		wake_up(&rdev->dev_wait);
239 		break;
240 	case NETDEV_UP:
241 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
242 
243 		rdev->opencount++;
244 		break;
245 	case NETDEV_UNREGISTER:
246 		/* It is possible to get NETDEV_UNREGISTER
247 		 * multiple times. To detect that, check
248 		 * that the interface is still on the list
249 		 * of registered interfaces, and only then
250 		 * remove and clean it up.
251 		 */
252 		if (!list_empty(&wpan_dev->list)) {
253 			list_del_rcu(&wpan_dev->list);
254 			rdev->devlist_generation++;
255 		}
256 		/* synchronize (so that we won't find this netdev
257 		 * from other code any more) and then clear the list
258 		 * head so that the above code can safely check for
259 		 * !list_empty() to avoid double-cleanup.
260 		 */
261 		synchronize_rcu();
262 		INIT_LIST_HEAD(&wpan_dev->list);
263 		break;
264 	default:
265 		return NOTIFY_DONE;
266 	}
267 
268 	return NOTIFY_OK;
269 }
270 
271 static struct notifier_block cfg802154_netdev_notifier = {
272 	.notifier_call = cfg802154_netdev_notifier_call,
273 };
274 
275 static int __init wpan_phy_class_init(void)
276 {
277 	int rc;
278 
279 	rc = wpan_phy_sysfs_init();
280 	if (rc)
281 		goto err;
282 
283 	rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
284 	if (rc)
285 		goto err_nl;
286 
287 	rc = ieee802154_nl_init();
288 	if (rc)
289 		goto err_notifier;
290 
291 	rc = nl802154_init();
292 	if (rc)
293 		goto err_ieee802154_nl;
294 
295 	return 0;
296 
297 err_ieee802154_nl:
298 	ieee802154_nl_exit();
299 
300 err_notifier:
301 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
302 err_nl:
303 	wpan_phy_sysfs_exit();
304 err:
305 	return rc;
306 }
307 subsys_initcall(wpan_phy_class_init);
308 
309 static void __exit wpan_phy_class_exit(void)
310 {
311 	nl802154_exit();
312 	ieee802154_nl_exit();
313 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
314 	wpan_phy_sysfs_exit();
315 }
316 module_exit(wpan_phy_class_exit);
317 
318 MODULE_LICENSE("GPL v2");
319 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
320 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
321 
322