xref: /kernel/linux/linux-6.6/net/ieee802154/core.c (revision 62306a36) 
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) */
23LIST_HEAD(cfg802154_rdev_list);
24int cfg802154_rdev_list_generation;
25
26struct 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}
39EXPORT_SYMBOL(wpan_phy_find);
40
41struct wpan_phy_iter_data {
42	int (*fn)(struct wpan_phy *phy, void *data);
43	void *data;
44};
45
46static 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
54int 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}
65EXPORT_SYMBOL(wpan_phy_for_each);
66
67struct cfg802154_registered_device *
68cfg802154_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
84struct 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
96struct wpan_phy *
97wpan_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	init_waitqueue_head(&rdev->wpan_phy.sync_txq);
133
134	spin_lock_init(&rdev->wpan_phy.queue_lock);
135
136	return &rdev->wpan_phy;
137}
138EXPORT_SYMBOL(wpan_phy_new);
139
140int wpan_phy_register(struct wpan_phy *phy)
141{
142	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
143	int ret;
144
145	rtnl_lock();
146	ret = device_add(&phy->dev);
147	if (ret) {
148		rtnl_unlock();
149		return ret;
150	}
151
152	list_add_rcu(&rdev->list, &cfg802154_rdev_list);
153	cfg802154_rdev_list_generation++;
154
155	/* TODO phy registered lock */
156	rtnl_unlock();
157
158	/* TODO nl802154 phy notify */
159
160	return 0;
161}
162EXPORT_SYMBOL(wpan_phy_register);
163
164void wpan_phy_unregister(struct wpan_phy *phy)
165{
166	struct cfg802154_registered_device *rdev = wpan_phy_to_rdev(phy);
167
168	wait_event(rdev->dev_wait, ({
169		int __count;
170		rtnl_lock();
171		__count = rdev->opencount;
172		rtnl_unlock();
173		__count == 0; }));
174
175	rtnl_lock();
176	/* TODO nl802154 phy notify */
177	/* TODO phy registered lock */
178
179	WARN_ON(!list_empty(&rdev->wpan_dev_list));
180
181	/* First remove the hardware from everywhere, this makes
182	 * it impossible to find from userspace.
183	 */
184	list_del_rcu(&rdev->list);
185	synchronize_rcu();
186
187	cfg802154_rdev_list_generation++;
188
189	device_del(&phy->dev);
190
191	rtnl_unlock();
192}
193EXPORT_SYMBOL(wpan_phy_unregister);
194
195void wpan_phy_free(struct wpan_phy *phy)
196{
197	put_device(&phy->dev);
198}
199EXPORT_SYMBOL(wpan_phy_free);
200
201int cfg802154_switch_netns(struct cfg802154_registered_device *rdev,
202			   struct net *net)
203{
204	struct wpan_dev *wpan_dev;
205	int err = 0;
206
207	list_for_each_entry(wpan_dev, &rdev->wpan_dev_list, list) {
208		if (!wpan_dev->netdev)
209			continue;
210		wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
211		err = dev_change_net_namespace(wpan_dev->netdev, net, "wpan%d");
212		if (err)
213			break;
214		wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
215	}
216
217	if (err) {
218		/* failed -- clean up to old netns */
219		net = wpan_phy_net(&rdev->wpan_phy);
220
221		list_for_each_entry_continue_reverse(wpan_dev,
222						     &rdev->wpan_dev_list,
223						     list) {
224			if (!wpan_dev->netdev)
225				continue;
226			wpan_dev->netdev->features &= ~NETIF_F_NETNS_LOCAL;
227			err = dev_change_net_namespace(wpan_dev->netdev, net,
228						       "wpan%d");
229			WARN_ON(err);
230			wpan_dev->netdev->features |= NETIF_F_NETNS_LOCAL;
231		}
232
233		return err;
234	}
235
236	wpan_phy_net_set(&rdev->wpan_phy, net);
237
238	err = device_rename(&rdev->wpan_phy.dev, dev_name(&rdev->wpan_phy.dev));
239	WARN_ON(err);
240
241	return 0;
242}
243
244void cfg802154_dev_free(struct cfg802154_registered_device *rdev)
245{
246	kfree(rdev);
247}
248
249static void
250cfg802154_update_iface_num(struct cfg802154_registered_device *rdev,
251			   int iftype, int num)
252{
253	ASSERT_RTNL();
254
255	rdev->num_running_ifaces += num;
256}
257
258static int cfg802154_netdev_notifier_call(struct notifier_block *nb,
259					  unsigned long state, void *ptr)
260{
261	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
262	struct wpan_dev *wpan_dev = dev->ieee802154_ptr;
263	struct cfg802154_registered_device *rdev;
264
265	if (!wpan_dev)
266		return NOTIFY_DONE;
267
268	rdev = wpan_phy_to_rdev(wpan_dev->wpan_phy);
269
270	/* TODO WARN_ON unspec type */
271
272	switch (state) {
273		/* TODO NETDEV_DEVTYPE */
274	case NETDEV_REGISTER:
275		dev->features |= NETIF_F_NETNS_LOCAL;
276		wpan_dev->identifier = ++rdev->wpan_dev_id;
277		list_add_rcu(&wpan_dev->list, &rdev->wpan_dev_list);
278		rdev->devlist_generation++;
279
280		wpan_dev->netdev = dev;
281		break;
282	case NETDEV_DOWN:
283		cfg802154_update_iface_num(rdev, wpan_dev->iftype, -1);
284
285		rdev->opencount--;
286		wake_up(&rdev->dev_wait);
287		break;
288	case NETDEV_UP:
289		cfg802154_update_iface_num(rdev, wpan_dev->iftype, 1);
290
291		rdev->opencount++;
292		break;
293	case NETDEV_UNREGISTER:
294		/* It is possible to get NETDEV_UNREGISTER
295		 * multiple times. To detect that, check
296		 * that the interface is still on the list
297		 * of registered interfaces, and only then
298		 * remove and clean it up.
299		 */
300		if (!list_empty(&wpan_dev->list)) {
301			list_del_rcu(&wpan_dev->list);
302			rdev->devlist_generation++;
303		}
304		/* synchronize (so that we won't find this netdev
305		 * from other code any more) and then clear the list
306		 * head so that the above code can safely check for
307		 * !list_empty() to avoid double-cleanup.
308		 */
309		synchronize_rcu();
310		INIT_LIST_HEAD(&wpan_dev->list);
311		break;
312	default:
313		return NOTIFY_DONE;
314	}
315
316	return NOTIFY_OK;
317}
318
319static struct notifier_block cfg802154_netdev_notifier = {
320	.notifier_call = cfg802154_netdev_notifier_call,
321};
322
323static void __net_exit cfg802154_pernet_exit(struct net *net)
324{
325	struct cfg802154_registered_device *rdev;
326
327	rtnl_lock();
328	list_for_each_entry(rdev, &cfg802154_rdev_list, list) {
329		if (net_eq(wpan_phy_net(&rdev->wpan_phy), net))
330			WARN_ON(cfg802154_switch_netns(rdev, &init_net));
331	}
332	rtnl_unlock();
333}
334
335static struct pernet_operations cfg802154_pernet_ops = {
336	.exit = cfg802154_pernet_exit,
337};
338
339static int __init wpan_phy_class_init(void)
340{
341	int rc;
342
343	rc = register_pernet_device(&cfg802154_pernet_ops);
344	if (rc)
345		goto err;
346
347	rc = wpan_phy_sysfs_init();
348	if (rc)
349		goto err_sysfs;
350
351	rc = register_netdevice_notifier(&cfg802154_netdev_notifier);
352	if (rc)
353		goto err_nl;
354
355	rc = ieee802154_nl_init();
356	if (rc)
357		goto err_notifier;
358
359	rc = nl802154_init();
360	if (rc)
361		goto err_ieee802154_nl;
362
363	return 0;
364
365err_ieee802154_nl:
366	ieee802154_nl_exit();
367
368err_notifier:
369	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
370err_nl:
371	wpan_phy_sysfs_exit();
372err_sysfs:
373	unregister_pernet_device(&cfg802154_pernet_ops);
374err:
375	return rc;
376}
377subsys_initcall(wpan_phy_class_init);
378
379static void __exit wpan_phy_class_exit(void)
380{
381	nl802154_exit();
382	ieee802154_nl_exit();
383	unregister_netdevice_notifier(&cfg802154_netdev_notifier);
384	wpan_phy_sysfs_exit();
385	unregister_pernet_device(&cfg802154_pernet_ops);
386}
387module_exit(wpan_phy_class_exit);
388
389MODULE_LICENSE("GPL v2");
390MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
391MODULE_AUTHOR("Dmitry Eremin-Solenikov");
392