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 */
28 static 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, ¬ified);
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
145 static struct notifier_block br_device_notifier = {
146 .notifier_call = br_device_event
147 };
148
149 /* called with RTNL or RCU */
150 static 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
197 out:
198 return err;
199 }
200
201 static struct notifier_block br_switchdev_notifier = {
202 .notifier_call = br_switchdev_event,
203 };
204
205 /* called under rtnl_mutex */
206 static 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
247 out:
248 return err;
249 }
250
251 static 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 */
265 int 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
289 int 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
307 int 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
329 void 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 */
343 void 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
359 static 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
372 static struct pernet_operations br_net_ops = {
373 .exit_batch_rtnl = br_net_exit_batch_rtnl,
374 };
375
376 static const struct stp_proto br_stp_proto = {
377 .rcv = br_stp_rcv,
378 };
379
380 static 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
434 err_out6:
435 unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
436 err_out5:
437 unregister_switchdev_notifier(&br_switchdev_notifier);
438 err_out4:
439 unregister_netdevice_notifier(&br_device_notifier);
440 err_out3:
441 br_nf_core_fini();
442 err_out2:
443 unregister_pernet_subsys(&br_net_ops);
444 err_out1:
445 br_fdb_fini();
446 err_out:
447 stp_proto_unregister(&br_stp_proto);
448 return err;
449 }
450
451 static 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
470 module_init(br_init)
471 module_exit(br_deinit)
472 MODULE_LICENSE("GPL");
473 MODULE_VERSION(BR_VERSION);
474 MODULE_ALIAS_RTNL_LINK("bridge");
475 MODULE_DESCRIPTION("Ethernet bridge driver");
476
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