1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *	Generic parts
4 *	Linux ethernet bridge
5 *
6 *	Authors:
7 *	Lennert Buytenhek		<buytenh@gnu.org>
8 */
9
10#include <linux/module.h>
11#include <linux/kernel.h>
12#include <linux/netdevice.h>
13#include <linux/etherdevice.h>
14#include <linux/init.h>
15#include <linux/llc.h>
16#include <net/llc.h>
17#include <net/stp.h>
18#include <net/switchdev.h>
19
20#include "br_private.h"
21
22/*
23 * Handle changes in state of network devices enslaved to a bridge.
24 *
25 * Note: don't care about up/down if bridge itself is down, because
26 *     port state is checked when bridge is brought up.
27 */
28static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
29{
30	struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(ptr);
31	struct netdev_notifier_pre_changeaddr_info *prechaddr_info;
32	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
33	struct net_bridge_port *p;
34	struct net_bridge *br;
35	bool notified = false;
36	bool changed_addr;
37	int err;
38
39	if (netif_is_bridge_master(dev)) {
40		err = br_vlan_bridge_event(dev, event, ptr);
41		if (err)
42			return notifier_from_errno(err);
43
44		if (event == NETDEV_REGISTER) {
45			/* register of bridge completed, add sysfs entries */
46			err = br_sysfs_addbr(dev);
47			if (err)
48				return notifier_from_errno(err);
49
50			return NOTIFY_DONE;
51		}
52	}
53
54	/* not a port of a bridge */
55	p = br_port_get_rtnl(dev);
56	if (!p)
57		return NOTIFY_DONE;
58
59	br = p->br;
60
61	switch (event) {
62	case NETDEV_CHANGEMTU:
63		br_mtu_auto_adjust(br);
64		break;
65
66	case NETDEV_PRE_CHANGEADDR:
67		if (br->dev->addr_assign_type == NET_ADDR_SET)
68			break;
69		prechaddr_info = ptr;
70		err = dev_pre_changeaddr_notify(br->dev,
71						prechaddr_info->dev_addr,
72						extack);
73		if (err)
74			return notifier_from_errno(err);
75		break;
76
77	case NETDEV_CHANGEADDR:
78		spin_lock_bh(&br->lock);
79		br_fdb_changeaddr(p, dev->dev_addr);
80		changed_addr = br_stp_recalculate_bridge_id(br);
81		spin_unlock_bh(&br->lock);
82
83		if (changed_addr)
84			call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
85
86		break;
87
88	case NETDEV_CHANGE:
89		br_port_carrier_check(p, &notified);
90		break;
91
92	case NETDEV_FEAT_CHANGE:
93		netdev_update_features(br->dev);
94		break;
95
96	case NETDEV_DOWN:
97		spin_lock_bh(&br->lock);
98		if (br->dev->flags & IFF_UP) {
99			br_stp_disable_port(p);
100			notified = true;
101		}
102		spin_unlock_bh(&br->lock);
103		break;
104
105	case NETDEV_UP:
106		if (netif_running(br->dev) && netif_oper_up(dev)) {
107			spin_lock_bh(&br->lock);
108			br_stp_enable_port(p);
109			notified = true;
110			spin_unlock_bh(&br->lock);
111		}
112		break;
113
114	case NETDEV_UNREGISTER:
115		br_del_if(br, dev);
116		break;
117
118	case NETDEV_CHANGENAME:
119		err = br_sysfs_renameif(p);
120		if (err)
121			return notifier_from_errno(err);
122		break;
123
124	case NETDEV_PRE_TYPE_CHANGE:
125		/* Forbid underlying device to change its type. */
126		return NOTIFY_BAD;
127
128	case NETDEV_RESEND_IGMP:
129		/* Propagate to master device */
130		call_netdevice_notifiers(event, br->dev);
131		break;
132	}
133
134	if (event != NETDEV_UNREGISTER)
135		br_vlan_port_event(p, event);
136
137	/* Events that may cause spanning tree to refresh */
138	if (!notified && (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
139			  event == NETDEV_CHANGE || event == NETDEV_DOWN))
140		br_ifinfo_notify(RTM_NEWLINK, NULL, p);
141
142	return NOTIFY_DONE;
143}
144
145static struct notifier_block br_device_notifier = {
146	.notifier_call = br_device_event
147};
148
149/* called with RTNL or RCU */
150static int br_switchdev_event(struct notifier_block *unused,
151			      unsigned long event, void *ptr)
152{
153	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
154	struct net_bridge_port *p;
155	struct net_bridge *br;
156	struct switchdev_notifier_fdb_info *fdb_info;
157	int err = NOTIFY_DONE;
158
159	p = br_port_get_rtnl_rcu(dev);
160	if (!p)
161		goto out;
162
163	br = p->br;
164
165	switch (event) {
166	case SWITCHDEV_FDB_ADD_TO_BRIDGE:
167		fdb_info = ptr;
168		err = br_fdb_external_learn_add(br, p, fdb_info->addr,
169						fdb_info->vid,
170						fdb_info->locked, false);
171		if (err) {
172			err = notifier_from_errno(err);
173			break;
174		}
175		br_fdb_offloaded_set(br, p, fdb_info->addr,
176				     fdb_info->vid, fdb_info->offloaded);
177		break;
178	case SWITCHDEV_FDB_DEL_TO_BRIDGE:
179		fdb_info = ptr;
180		err = br_fdb_external_learn_del(br, p, fdb_info->addr,
181						fdb_info->vid, false);
182		if (err)
183			err = notifier_from_errno(err);
184		break;
185	case SWITCHDEV_FDB_OFFLOADED:
186		fdb_info = ptr;
187		br_fdb_offloaded_set(br, p, fdb_info->addr,
188				     fdb_info->vid, fdb_info->offloaded);
189		break;
190	case SWITCHDEV_FDB_FLUSH_TO_BRIDGE:
191		fdb_info = ptr;
192		/* Don't delete static entries */
193		br_fdb_delete_by_port(br, p, fdb_info->vid, 0);
194		break;
195	}
196
197out:
198	return err;
199}
200
201static struct notifier_block br_switchdev_notifier = {
202	.notifier_call = br_switchdev_event,
203};
204
205/* called under rtnl_mutex */
206static int br_switchdev_blocking_event(struct notifier_block *nb,
207				       unsigned long event, void *ptr)
208{
209	struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(ptr);
210	struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
211	struct switchdev_notifier_brport_info *brport_info;
212	const struct switchdev_brport *b;
213	struct net_bridge_port *p;
214	int err = NOTIFY_DONE;
215
216	p = br_port_get_rtnl(dev);
217	if (!p)
218		goto out;
219
220	switch (event) {
221	case SWITCHDEV_BRPORT_OFFLOADED:
222		brport_info = ptr;
223		b = &brport_info->brport;
224
225		err = br_switchdev_port_offload(p, b->dev, b->ctx,
226						b->atomic_nb, b->blocking_nb,
227						b->tx_fwd_offload, extack);
228		err = notifier_from_errno(err);
229		break;
230	case SWITCHDEV_BRPORT_UNOFFLOADED:
231		brport_info = ptr;
232		b = &brport_info->brport;
233
234		br_switchdev_port_unoffload(p, b->ctx, b->atomic_nb,
235					    b->blocking_nb);
236		break;
237	case SWITCHDEV_BRPORT_REPLAY:
238		brport_info = ptr;
239		b = &brport_info->brport;
240
241		err = br_switchdev_port_replay(p, b->dev, b->ctx, b->atomic_nb,
242					       b->blocking_nb, extack);
243		err = notifier_from_errno(err);
244		break;
245	}
246
247out:
248	return err;
249}
250
251static struct notifier_block br_switchdev_blocking_notifier = {
252	.notifier_call = br_switchdev_blocking_event,
253};
254
255/* br_boolopt_toggle - change user-controlled boolean option
256 *
257 * @br: bridge device
258 * @opt: id of the option to change
259 * @on: new option value
260 * @extack: extack for error messages
261 *
262 * Changes the value of the respective boolean option to @on taking care of
263 * any internal option value mapping and configuration.
264 */
265int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
266		      struct netlink_ext_ack *extack)
267{
268	int err = 0;
269
270	switch (opt) {
271	case BR_BOOLOPT_NO_LL_LEARN:
272		br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
273		break;
274	case BR_BOOLOPT_MCAST_VLAN_SNOOPING:
275		err = br_multicast_toggle_vlan_snooping(br, on, extack);
276		break;
277	case BR_BOOLOPT_MST_ENABLE:
278		err = br_mst_set_enabled(br, on, extack);
279		break;
280	default:
281		/* shouldn't be called with unsupported options */
282		WARN_ON(1);
283		break;
284	}
285
286	return err;
287}
288
289int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
290{
291	switch (opt) {
292	case BR_BOOLOPT_NO_LL_LEARN:
293		return br_opt_get(br, BROPT_NO_LL_LEARN);
294	case BR_BOOLOPT_MCAST_VLAN_SNOOPING:
295		return br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED);
296	case BR_BOOLOPT_MST_ENABLE:
297		return br_opt_get(br, BROPT_MST_ENABLED);
298	default:
299		/* shouldn't be called with unsupported options */
300		WARN_ON(1);
301		break;
302	}
303
304	return 0;
305}
306
307int br_boolopt_multi_toggle(struct net_bridge *br,
308			    struct br_boolopt_multi *bm,
309			    struct netlink_ext_ack *extack)
310{
311	unsigned long bitmap = bm->optmask;
312	int err = 0;
313	int opt_id;
314
315	for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
316		bool on = !!(bm->optval & BIT(opt_id));
317
318		err = br_boolopt_toggle(br, opt_id, on, extack);
319		if (err) {
320			br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
321				 opt_id, br_boolopt_get(br, opt_id), on, err);
322			break;
323		}
324	}
325
326	return err;
327}
328
329void br_boolopt_multi_get(const struct net_bridge *br,
330			  struct br_boolopt_multi *bm)
331{
332	u32 optval = 0;
333	int opt_id;
334
335	for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
336		optval |= (br_boolopt_get(br, opt_id) << opt_id);
337
338	bm->optval = optval;
339	bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
340}
341
342/* private bridge options, controlled by the kernel */
343void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
344{
345	bool cur = !!br_opt_get(br, opt);
346
347	br_debug(br, "toggle option: %d state: %d -> %d\n",
348		 opt, cur, on);
349
350	if (cur == on)
351		return;
352
353	if (on)
354		set_bit(opt, &br->options);
355	else
356		clear_bit(opt, &br->options);
357}
358
359static void __net_exit br_net_exit_batch_rtnl(struct list_head *net_list,
360					      struct list_head *dev_to_kill)
361{
362	struct net_device *dev;
363	struct net *net;
364
365	ASSERT_RTNL();
366	list_for_each_entry(net, net_list, exit_list)
367		for_each_netdev(net, dev)
368			if (netif_is_bridge_master(dev))
369				br_dev_delete(dev, dev_to_kill);
370}
371
372static struct pernet_operations br_net_ops = {
373	.exit_batch_rtnl = br_net_exit_batch_rtnl,
374};
375
376static const struct stp_proto br_stp_proto = {
377	.rcv	= br_stp_rcv,
378};
379
380static int __init br_init(void)
381{
382	int err;
383
384	BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
385
386	err = stp_proto_register(&br_stp_proto);
387	if (err < 0) {
388		pr_err("bridge: can't register sap for STP\n");
389		return err;
390	}
391
392	err = br_fdb_init();
393	if (err)
394		goto err_out;
395
396	err = register_pernet_subsys(&br_net_ops);
397	if (err)
398		goto err_out1;
399
400	err = br_nf_core_init();
401	if (err)
402		goto err_out2;
403
404	err = register_netdevice_notifier(&br_device_notifier);
405	if (err)
406		goto err_out3;
407
408	err = register_switchdev_notifier(&br_switchdev_notifier);
409	if (err)
410		goto err_out4;
411
412	err = register_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
413	if (err)
414		goto err_out5;
415
416	err = br_netlink_init();
417	if (err)
418		goto err_out6;
419
420	brioctl_set(br_ioctl_stub);
421
422#if IS_ENABLED(CONFIG_ATM_LANE)
423	br_fdb_test_addr_hook = br_fdb_test_addr;
424#endif
425
426#if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
427	pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
428		"by default. Update your scripts to load br_netfilter if you "
429		"need this.\n");
430#endif
431
432	return 0;
433
434err_out6:
435	unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
436err_out5:
437	unregister_switchdev_notifier(&br_switchdev_notifier);
438err_out4:
439	unregister_netdevice_notifier(&br_device_notifier);
440err_out3:
441	br_nf_core_fini();
442err_out2:
443	unregister_pernet_subsys(&br_net_ops);
444err_out1:
445	br_fdb_fini();
446err_out:
447	stp_proto_unregister(&br_stp_proto);
448	return err;
449}
450
451static void __exit br_deinit(void)
452{
453	stp_proto_unregister(&br_stp_proto);
454	br_netlink_fini();
455	unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
456	unregister_switchdev_notifier(&br_switchdev_notifier);
457	unregister_netdevice_notifier(&br_device_notifier);
458	brioctl_set(NULL);
459	unregister_pernet_subsys(&br_net_ops);
460
461	rcu_barrier(); /* Wait for completion of call_rcu()'s */
462
463	br_nf_core_fini();
464#if IS_ENABLED(CONFIG_ATM_LANE)
465	br_fdb_test_addr_hook = NULL;
466#endif
467	br_fdb_fini();
468}
469
470module_init(br_init)
471module_exit(br_deinit)
472MODULE_LICENSE("GPL");
473MODULE_VERSION(BR_VERSION);
474MODULE_ALIAS_RTNL_LINK("bridge");
475MODULE_DESCRIPTION("Ethernet bridge driver");
476