xref: /kernel/linux/linux-5.10/net/bridge/br.c (revision 8c2ecf20) 
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 (dev->priv_flags & IFF_EBRIDGE) {
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 underlaying 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, false);
170		if (err) {
171			err = notifier_from_errno(err);
172			break;
173		}
174		br_fdb_offloaded_set(br, p, fdb_info->addr,
175				     fdb_info->vid, true);
176		break;
177	case SWITCHDEV_FDB_DEL_TO_BRIDGE:
178		fdb_info = ptr;
179		err = br_fdb_external_learn_del(br, p, fdb_info->addr,
180						fdb_info->vid, false);
181		if (err)
182			err = notifier_from_errno(err);
183		break;
184	case SWITCHDEV_FDB_OFFLOADED:
185		fdb_info = ptr;
186		br_fdb_offloaded_set(br, p, fdb_info->addr,
187				     fdb_info->vid, fdb_info->offloaded);
188		break;
189	case SWITCHDEV_FDB_FLUSH_TO_BRIDGE:
190		fdb_info = ptr;
191		/* Don't delete static entries */
192		br_fdb_delete_by_port(br, p, fdb_info->vid, 0);
193		break;
194	}
195
196out:
197	return err;
198}
199
200static struct notifier_block br_switchdev_notifier = {
201	.notifier_call = br_switchdev_event,
202};
203
204/* br_boolopt_toggle - change user-controlled boolean option
205 *
206 * @br: bridge device
207 * @opt: id of the option to change
208 * @on: new option value
209 * @extack: extack for error messages
210 *
211 * Changes the value of the respective boolean option to @on taking care of
212 * any internal option value mapping and configuration.
213 */
214int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
215		      struct netlink_ext_ack *extack)
216{
217	switch (opt) {
218	case BR_BOOLOPT_NO_LL_LEARN:
219		br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
220		break;
221	default:
222		/* shouldn't be called with unsupported options */
223		WARN_ON(1);
224		break;
225	}
226
227	return 0;
228}
229
230int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
231{
232	switch (opt) {
233	case BR_BOOLOPT_NO_LL_LEARN:
234		return br_opt_get(br, BROPT_NO_LL_LEARN);
235	default:
236		/* shouldn't be called with unsupported options */
237		WARN_ON(1);
238		break;
239	}
240
241	return 0;
242}
243
244int br_boolopt_multi_toggle(struct net_bridge *br,
245			    struct br_boolopt_multi *bm,
246			    struct netlink_ext_ack *extack)
247{
248	unsigned long bitmap = bm->optmask;
249	int err = 0;
250	int opt_id;
251
252	for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
253		bool on = !!(bm->optval & BIT(opt_id));
254
255		err = br_boolopt_toggle(br, opt_id, on, extack);
256		if (err) {
257			br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
258				 opt_id, br_boolopt_get(br, opt_id), on, err);
259			break;
260		}
261	}
262
263	return err;
264}
265
266void br_boolopt_multi_get(const struct net_bridge *br,
267			  struct br_boolopt_multi *bm)
268{
269	u32 optval = 0;
270	int opt_id;
271
272	for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
273		optval |= (br_boolopt_get(br, opt_id) << opt_id);
274
275	bm->optval = optval;
276	bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
277}
278
279/* private bridge options, controlled by the kernel */
280void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
281{
282	bool cur = !!br_opt_get(br, opt);
283
284	br_debug(br, "toggle option: %d state: %d -> %d\n",
285		 opt, cur, on);
286
287	if (cur == on)
288		return;
289
290	if (on)
291		set_bit(opt, &br->options);
292	else
293		clear_bit(opt, &br->options);
294}
295
296static void __net_exit br_net_exit(struct net *net)
297{
298	struct net_device *dev;
299	LIST_HEAD(list);
300
301	rtnl_lock();
302	for_each_netdev(net, dev)
303		if (dev->priv_flags & IFF_EBRIDGE)
304			br_dev_delete(dev, &list);
305
306	unregister_netdevice_many(&list);
307	rtnl_unlock();
308
309}
310
311static struct pernet_operations br_net_ops = {
312	.exit	= br_net_exit,
313};
314
315static const struct stp_proto br_stp_proto = {
316	.rcv	= br_stp_rcv,
317};
318
319static int __init br_init(void)
320{
321	int err;
322
323	BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
324
325	err = stp_proto_register(&br_stp_proto);
326	if (err < 0) {
327		pr_err("bridge: can't register sap for STP\n");
328		return err;
329	}
330
331	err = br_fdb_init();
332	if (err)
333		goto err_out;
334
335	err = register_pernet_subsys(&br_net_ops);
336	if (err)
337		goto err_out1;
338
339	err = br_nf_core_init();
340	if (err)
341		goto err_out2;
342
343	err = register_netdevice_notifier(&br_device_notifier);
344	if (err)
345		goto err_out3;
346
347	err = register_switchdev_notifier(&br_switchdev_notifier);
348	if (err)
349		goto err_out4;
350
351	err = br_netlink_init();
352	if (err)
353		goto err_out5;
354
355	brioctl_set(br_ioctl_deviceless_stub);
356
357#if IS_ENABLED(CONFIG_ATM_LANE)
358	br_fdb_test_addr_hook = br_fdb_test_addr;
359#endif
360
361#if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
362	pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
363		"by default. Update your scripts to load br_netfilter if you "
364		"need this.\n");
365#endif
366
367	return 0;
368
369err_out5:
370	unregister_switchdev_notifier(&br_switchdev_notifier);
371err_out4:
372	unregister_netdevice_notifier(&br_device_notifier);
373err_out3:
374	br_nf_core_fini();
375err_out2:
376	unregister_pernet_subsys(&br_net_ops);
377err_out1:
378	br_fdb_fini();
379err_out:
380	stp_proto_unregister(&br_stp_proto);
381	return err;
382}
383
384static void __exit br_deinit(void)
385{
386	stp_proto_unregister(&br_stp_proto);
387	br_netlink_fini();
388	unregister_switchdev_notifier(&br_switchdev_notifier);
389	unregister_netdevice_notifier(&br_device_notifier);
390	brioctl_set(NULL);
391	unregister_pernet_subsys(&br_net_ops);
392
393	rcu_barrier(); /* Wait for completion of call_rcu()'s */
394
395	br_nf_core_fini();
396#if IS_ENABLED(CONFIG_ATM_LANE)
397	br_fdb_test_addr_hook = NULL;
398#endif
399	br_fdb_fini();
400}
401
402module_init(br_init)
403module_exit(br_deinit)
404MODULE_LICENSE("GPL");
405MODULE_VERSION(BR_VERSION);
406MODULE_ALIAS_RTNL_LINK("bridge");
407