xref: /openbmc/linux/net/ieee802154/core.c (revision 74be2d3b) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2007, 2008, 2009 Siemens AG
4  */
5 
6 #include <linux/slab.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/device.h>
10 
11 #include <net/cfg802154.h>
12 #include <net/rtnetlink.h>
13 
14 #include "ieee802154.h"
15 #include "nl802154.h"
16 #include "sysfs.h"
17 #include "core.h"
18 
19 /* name for sysfs, %d is appended */
20 #define PHY_NAME "phy"
21 
22 /* RCU-protected (and RTNL for writers) */
23 LIST_HEAD(cfg802154_rdev_list);
24 int cfg802154_rdev_list_generation;
25 
26 struct wpan_phy *wpan_phy_find(const char *str)
27 {
28 	struct device *dev;
29 
30 	if (WARN_ON(!str))
31 		return NULL;
32 
33 	dev = class_find_device_by_name(&wpan_phy_class, str);
34 	if (!dev)
35 		return NULL;
36 
37 	return container_of(dev, struct wpan_phy, dev);
38 }
39 EXPORT_SYMBOL(wpan_phy_find);
40 
41 struct wpan_phy_iter_data {
42 	int (*fn)(struct wpan_phy *phy, void *data);
43 	void *data;
44 };
45 
46 static int wpan_phy_iter(struct device *dev, void *_data)
47 {
48 	struct wpan_phy_iter_data *wpid = _data;
49 	struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);
50 
51 	return wpid->fn(phy, wpid->data);
52 }
53 
54 int wpan_phy_for_each(int (*fn)(struct wpan_phy *phy, void *data),
55 		      void *data)
56 {
57 	struct wpan_phy_iter_data wpid = {
58 		.fn = fn,
59 		.data = data,
60 	};
61 
62 	return class_for_each_device(&wpan_phy_class, NULL,
63 			&wpid, wpan_phy_iter);
64 }
65 EXPORT_SYMBOL(wpan_phy_for_each);
66 
67 struct cfg802154_registered_device *
68 cfg802154_rdev_by_wpan_phy_idx(int wpan_phy_idx)
69 {
70 	struct cfg802154_registered_device *result = NULL, *rdev;
71 
72 	ASSERT_RTNL();
73 
74 	list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
75 		if (rdev->wpan_phy_idx == wpan_phy_idx) {
76 			result = rdev;
77 			break;
78 		}
79 	}
80 
81 	return result;
82 }
83 
84 struct wpan_phy *wpan_phy_idx_to_wpan_phy(int wpan_phy_idx)
85 {
86 	struct cfg802154_registered_device *rdev;
87 
88 	ASSERT_RTNL();
89 
90 	rdev = cfg802154_rdev_by_wpan_phy_idx(wpan_phy_idx);
91 	if (!rdev)
92 		return NULL;
93 	return &rdev->wpan_phy;
94 }
95 
96 struct wpan_phy *
97 wpan_phy_new(const struct cfg802154_ops *ops, size_t priv_size)
98 {
99 	static atomic_t wpan_phy_counter = ATOMIC_INIT(0);
100 	struct cfg802154_registered_device *rdev;
101 	size_t alloc_size;
102 
103 	alloc_size = sizeof(*rdev) + priv_size;
104 	rdev = kzalloc(alloc_size, GFP_KERNEL);
105 	if (!rdev)
106 		return NULL;
107 
108 	rdev->ops = ops;
109 
110 	rdev->wpan_phy_idx = atomic_inc_return(&wpan_phy_counter);
111 
112 	if (unlikely(rdev->wpan_phy_idx < 0)) {
113 		/* ugh, wrapped! */
114 		atomic_dec(&wpan_phy_counter);
115 		kfree(rdev);
116 		return NULL;
117 	}
118 
119 	/* atomic_inc_return makes it start at 1, make it start at 0 */
120 	rdev->wpan_phy_idx--;
121 
122 	INIT_LIST_HEAD(&rdev->wpan_dev_list);
123 	device_initialize(&rdev->wpan_phy.dev);
124 	dev_set_name(&rdev->wpan_phy.dev, PHY_NAME "%d", rdev->wpan_phy_idx);
125 
126 	rdev->wpan_phy.dev.class = &wpan_phy_class;
127 	rdev->wpan_phy.dev.platform_data = rdev;
128 
129 	wpan_phy_net_set(&rdev->wpan_phy, &init_net);
130 
131 	init_waitqueue_head(&rdev->dev_wait);
132 
133 	return &rdev->wpan_phy;
134 }
135 EXPORT_SYMBOL(wpan_phy_new);
136 
137 int wpan_phy_register(struct wpan_phy *phy)
138 {
139 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
140 	int ret;
141 
142 	rtnl_lock();
143 	ret = device_add(&phy->dev);
144 	if (ret) {
145 		rtnl_unlock();
146 		return ret;
147 	}
148 
149 	list_add_rcu(&rdev->list, &cfg802154_rdev_list);
150 	cfg802154_rdev_list_generation++;
151 
152 	/* TODO phy registered lock */
153 	rtnl_unlock();
154 
155 	/* TODO nl802154 phy notify */
156 
157 	return 0;
158 }
159 EXPORT_SYMBOL(wpan_phy_register);
160 
161 void wpan_phy_unregister(struct wpan_phy *phy)
162 {
163 	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
164 
165 	wait_event(rdev->dev_wait, ({
166 		int __count;
167 		rtnl_lock();
168 		__count = rdev->opencount;
169 		rtnl_unlock();
170 		__count == 0; }));
171 
172 	rtnl_lock();
173 	/* TODO nl802154 phy notify */
174 	/* TODO phy registered lock */
175 
176 	WARN_ON(!list_empty(&rdev->wpan_dev_list));
177 
178 	/* First remove the hardware from everywhere, this makes
179 	 * it impossible to find from userspace.
180 	 */
181 	list_del_rcu(&rdev->list);
182 	synchronize_rcu();
183 
184 	cfg802154_rdev_list_generation++;
185 
186 	device_del(&phy->dev);
187 
188 	rtnl_unlock();
189 }
190 EXPORT_SYMBOL(wpan_phy_unregister);
191 
192 void wpan_phy_free(struct wpan_phy *phy)
193 {
194 	put_device(&phy->dev);
195 }
196 EXPORT_SYMBOL(wpan_phy_free);
197 
198 int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
199 			   struct net *net)
200 {
201 	struct wpan_dev *wpan_dev;
202 	int err = 0;
203 
204 	list_for_each_entry(wpan_dev, &rdev->wpan_dev_list, list) {
205 		if (!wpan_dev->netdev)
206 			continue;
207 		wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
208 		err = dev_change_net_namespace(wpan_dev->netdev, net, "wpan%d");
209 		if (err)
210 			break;
211 		wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
212 	}
213 
214 	if (err) {
215 		/* failed -- clean up to old netns */
216 		net = wpan_phy_net(&rdev->wpan_phy);
217 
218 		list_for_each_entry_continue_reverse(wpan_dev,
219 						     &rdev->wpan_dev_list,
220 						     list) {
221 			if (!wpan_dev->netdev)
222 				continue;
223 			wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
224 			err = dev_change_net_namespace(wpan_dev->netdev, net,
225 						       "wpan%d");
226 			WARN_ON(err);
227 			wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
228 		}
229 
230 		return err;
231 	}
232 
233 	wpan_phy_net_set(&rdev->wpan_phy, net);
234 
235 	err = device_rename(&rdev->wpan_phy.dev, dev_name(&rdev->wpan_phy.dev));
236 	WARN_ON(err);
237 
238 	return 0;
239 }
240 
241 void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
242 {
243 	kfree(rdev);
244 }
245 
246 static void
247 cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
248 			   int iftype, int num)
249 {
250 	ASSERT_RTNL();
251 
252 	rdev->num_running_ifaces += num;
253 }
254 
255 static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
256 					  unsigned long state, void *ptr)
257 {
258 	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
259 	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
260 	struct cfg802154_registered_device *rdev;
261 
262 	if (!wpan_dev)
263 		return NOTIFY_DONE;
264 
265 	rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
266 
267 	/* TODO WARN_ON unspec type */
268 
269 	switch (state) {
270 		/* TODO NETDEV_DEVTYPE */
271 	case NETDEV_REGISTER:
272 		dev->features |= NETIF_F_NETNS_LOCAL;
273 		wpan_dev->identifier = ++rdev->wpan_dev_id;
274 		list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
275 		rdev->devlist_generation++;
276 
277 		wpan_dev->netdev = dev;
278 		break;
279 	case NETDEV_DOWN:
280 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
281 
282 		rdev->opencount--;
283 		wake_up(&rdev->dev_wait);
284 		break;
285 	case NETDEV_UP:
286 		cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
287 
288 		rdev->opencount++;
289 		break;
290 	case NETDEV_UNREGISTER:
291 		/* It is possible to get NETDEV_UNREGISTER
292 		 * multiple times. To detect that, check
293 		 * that the interface is still on the list
294 		 * of registered interfaces, and only then
295 		 * remove and clean it up.
296 		 */
297 		if (!list_empty(&wpan_dev->list)) {
298 			list_del_rcu(&wpan_dev->list);
299 			rdev->devlist_generation++;
300 		}
301 		/* synchronize (so that we won't find this netdev
302 		 * from other code any more) and then clear the list
303 		 * head so that the above code can safely check for
304 		 * !list_empty() to avoid double-cleanup.
305 		 */
306 		synchronize_rcu();
307 		INIT_LIST_HEAD(&wpan_dev->list);
308 		break;
309 	default:
310 		return NOTIFY_DONE;
311 	}
312 
313 	return NOTIFY_OK;
314 }
315 
316 static struct notifier_block cfg802154_netdev_notifier = {
317 	.notifier_call = cfg802154_netdev_notifier_call,
318 };
319 
320 static void __net_exit cfg802154_pernet_exit(struct net *net)
321 {
322 	struct cfg802154_registered_device *rdev;
323 
324 	rtnl_lock();
325 	list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
326 		if (net_eq(wpan_phy_net(&rdev->wpan_phy), net))
327 			WARN_ON(cfg802154_switch_netns(rdev, &init_net));
328 	}
329 	rtnl_unlock();
330 }
331 
332 static struct pernet_operations cfg802154_pernet_ops = {
333 	.exit = cfg802154_pernet_exit,
334 };
335 
336 static int __init wpan_phy_class_init(void)
337 {
338 	int rc;
339 
340 	rc = register_pernet_device(&cfg802154_pernet_ops);
341 	if (rc)
342 		goto err;
343 
344 	rc = wpan_phy_sysfs_init();
345 	if (rc)
346 		goto err_sysfs;
347 
348 	rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
349 	if (rc)
350 		goto err_nl;
351 
352 	rc = ieee802154_nl_init();
353 	if (rc)
354 		goto err_notifier;
355 
356 	rc = nl802154_init();
357 	if (rc)
358 		goto err_ieee802154_nl;
359 
360 	return 0;
361 
362 err_ieee802154_nl:
363 	ieee802154_nl_exit();
364 
365 err_notifier:
366 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
367 err_nl:
368 	wpan_phy_sysfs_exit();
369 err_sysfs:
370 	unregister_pernet_device(&cfg802154_pernet_ops);
371 err:
372 	return rc;
373 }
374 subsys_initcall(wpan_phy_class_init);
375 
376 static void __exit wpan_phy_class_exit(void)
377 {
378 	nl802154_exit();
379 	ieee802154_nl_exit();
380 	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
381 	wpan_phy_sysfs_exit();
382 	unregister_pernet_device(&cfg802154_pernet_ops);
383 }
384 module_exit(wpan_phy_class_exit);
385 
386 MODULE_LICENSE("GPL v2");
387 MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
388 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
389