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 */
br_device_event(struct notifier_block * unused,unsigned long event,void * ptr)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 struct net_bridge *br = netdev_priv(dev);
41
42 if (event == NETDEV_REGISTER)
43 br_fdb_change_mac_address(br, dev->dev_addr);
44
45 err = br_vlan_bridge_event(dev, event, ptr);
46 if (err)
47 return notifier_from_errno(err);
48
49 if (event == NETDEV_REGISTER) {
50 /* register of bridge completed, add sysfs entries */
51 err = br_sysfs_addbr(dev);
52 if (err)
53 return notifier_from_errno(err);
54
55 return NOTIFY_DONE;
56 }
57 }
58
59 if (is_vlan_dev(dev)) {
60 struct net_device *real_dev = vlan_dev_real_dev(dev);
61
62 if (netif_is_bridge_master(real_dev))
63 br_vlan_vlan_upper_event(real_dev, dev, event);
64 }
65
66 /* not a port of a bridge */
67 p = br_port_get_rtnl(dev);
68 if (!p)
69 return NOTIFY_DONE;
70
71 br = p->br;
72
73 switch (event) {
74 case NETDEV_CHANGEMTU:
75 br_mtu_auto_adjust(br);
76 break;
77
78 case NETDEV_PRE_CHANGEADDR:
79 if (br->dev->addr_assign_type == NET_ADDR_SET)
80 break;
81 prechaddr_info = ptr;
82 err = netif_pre_changeaddr_notify(br->dev,
83 prechaddr_info->dev_addr,
84 extack);
85 if (err)
86 return notifier_from_errno(err);
87 break;
88
89 case NETDEV_CHANGEADDR:
90 spin_lock_bh(&br->lock);
91 br_fdb_changeaddr(p, dev->dev_addr);
92 changed_addr = br_stp_recalculate_bridge_id(br);
93 spin_unlock_bh(&br->lock);
94
95 if (changed_addr)
96 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
97
98 break;
99
100 case NETDEV_CHANGE:
101 br_port_carrier_check(p, ¬ified);
102 break;
103
104 case NETDEV_FEAT_CHANGE:
105 netdev_update_features(br->dev);
106 break;
107
108 case NETDEV_DOWN:
109 spin_lock_bh(&br->lock);
110 if (br->dev->flags & IFF_UP) {
111 br_stp_disable_port(p);
112 notified = true;
113 }
114 spin_unlock_bh(&br->lock);
115 break;
116
117 case NETDEV_UP:
118 if (netif_running(br->dev) && netif_oper_up(dev)) {
119 spin_lock_bh(&br->lock);
120 br_stp_enable_port(p);
121 notified = true;
122 spin_unlock_bh(&br->lock);
123 }
124 break;
125
126 case NETDEV_UNREGISTER:
127 br_del_if(br, dev);
128 break;
129
130 case NETDEV_CHANGENAME:
131 err = br_sysfs_renameif(p);
132 if (err)
133 return notifier_from_errno(err);
134 break;
135
136 case NETDEV_PRE_TYPE_CHANGE:
137 /* Forbid underlying device to change its type. */
138 return NOTIFY_BAD;
139
140 case NETDEV_RESEND_IGMP:
141 /* Propagate to master device */
142 call_netdevice_notifiers(event, br->dev);
143 break;
144 }
145
146 if (event != NETDEV_UNREGISTER)
147 br_vlan_port_event(p, event);
148
149 /* Events that may cause spanning tree to refresh */
150 if (!notified && (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
151 event == NETDEV_CHANGE || event == NETDEV_DOWN))
152 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
153
154 return NOTIFY_DONE;
155 }
156
157 static struct notifier_block br_device_notifier = {
158 .notifier_call = br_device_event
159 };
160
161 /* called with RTNL or RCU */
br_switchdev_event(struct notifier_block * unused,unsigned long event,void * ptr)162 static int br_switchdev_event(struct notifier_block *unused,
163 unsigned long event, void *ptr)
164 {
165 struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
166 struct net_bridge_port *p;
167 struct net_bridge *br;
168 struct switchdev_notifier_fdb_info *fdb_info;
169 int err = NOTIFY_DONE;
170
171 p = br_port_get_rtnl_rcu(dev);
172 if (!p)
173 goto out;
174
175 br = p->br;
176
177 switch (event) {
178 case SWITCHDEV_FDB_ADD_TO_BRIDGE:
179 fdb_info = ptr;
180 err = br_fdb_external_learn_add(br, p, fdb_info->addr,
181 fdb_info->vid,
182 fdb_info->locked, false);
183 if (err) {
184 err = notifier_from_errno(err);
185 break;
186 }
187 br_fdb_offloaded_set(br, p, fdb_info->addr,
188 fdb_info->vid, fdb_info->offloaded);
189 break;
190 case SWITCHDEV_FDB_DEL_TO_BRIDGE:
191 fdb_info = ptr;
192 err = br_fdb_external_learn_del(br, p, fdb_info->addr,
193 fdb_info->vid, false);
194 if (err)
195 err = notifier_from_errno(err);
196 break;
197 case SWITCHDEV_FDB_OFFLOADED:
198 fdb_info = ptr;
199 br_fdb_offloaded_set(br, p, fdb_info->addr,
200 fdb_info->vid, fdb_info->offloaded);
201 break;
202 case SWITCHDEV_FDB_FLUSH_TO_BRIDGE:
203 fdb_info = ptr;
204 /* Don't delete static entries */
205 br_fdb_delete_by_port(br, p, fdb_info->vid, 0);
206 break;
207 }
208
209 out:
210 return err;
211 }
212
213 static struct notifier_block br_switchdev_notifier = {
214 .notifier_call = br_switchdev_event,
215 };
216
217 /* called under rtnl_mutex */
br_switchdev_blocking_event(struct notifier_block * nb,unsigned long event,void * ptr)218 static int br_switchdev_blocking_event(struct notifier_block *nb,
219 unsigned long event, void *ptr)
220 {
221 struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(ptr);
222 struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
223 struct switchdev_notifier_brport_info *brport_info;
224 const struct switchdev_brport *b;
225 struct net_bridge_port *p;
226 int err = NOTIFY_DONE;
227
228 p = br_port_get_rtnl(dev);
229 if (!p)
230 goto out;
231
232 switch (event) {
233 case SWITCHDEV_BRPORT_OFFLOADED:
234 brport_info = ptr;
235 b = &brport_info->brport;
236
237 err = br_switchdev_port_offload(p, b->dev, b->ctx,
238 b->atomic_nb, b->blocking_nb,
239 b->tx_fwd_offload, extack);
240 err = notifier_from_errno(err);
241 break;
242 case SWITCHDEV_BRPORT_UNOFFLOADED:
243 brport_info = ptr;
244 b = &brport_info->brport;
245
246 br_switchdev_port_unoffload(p, b->ctx, b->atomic_nb,
247 b->blocking_nb);
248 break;
249 case SWITCHDEV_BRPORT_REPLAY:
250 brport_info = ptr;
251 b = &brport_info->brport;
252
253 err = br_switchdev_port_replay(p, b->dev, b->ctx, b->atomic_nb,
254 b->blocking_nb, extack);
255 err = notifier_from_errno(err);
256 break;
257 }
258
259 out:
260 return err;
261 }
262
263 static struct notifier_block br_switchdev_blocking_notifier = {
264 .notifier_call = br_switchdev_blocking_event,
265 };
266
267 static int
br_toggle_fdb_local_vlan_0(struct net_bridge * br,bool on,struct netlink_ext_ack * extack)268 br_toggle_fdb_local_vlan_0(struct net_bridge *br, bool on,
269 struct netlink_ext_ack *extack)
270 {
271 int err;
272
273 if (br_opt_get(br, BROPT_FDB_LOCAL_VLAN_0) == on)
274 return 0;
275
276 err = br_fdb_toggle_local_vlan_0(br, on, extack);
277 if (err)
278 return err;
279
280 br_opt_toggle(br, BROPT_FDB_LOCAL_VLAN_0, on);
281 return 0;
282 }
283
284 /* br_boolopt_toggle - change user-controlled boolean option
285 *
286 * @br: bridge device
287 * @opt: id of the option to change
288 * @on: new option value
289 * @extack: extack for error messages
290 *
291 * Changes the value of the respective boolean option to @on taking care of
292 * any internal option value mapping and configuration.
293 */
br_boolopt_toggle(struct net_bridge * br,enum br_boolopt_id opt,bool on,struct netlink_ext_ack * extack)294 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
295 struct netlink_ext_ack *extack)
296 {
297 int err = 0;
298
299 switch (opt) {
300 case BR_BOOLOPT_NO_LL_LEARN:
301 br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
302 break;
303 case BR_BOOLOPT_MCAST_VLAN_SNOOPING:
304 err = br_multicast_toggle_vlan_snooping(br, on, extack);
305 break;
306 case BR_BOOLOPT_MST_ENABLE:
307 err = br_mst_set_enabled(br, on, extack);
308 break;
309 case BR_BOOLOPT_MDB_OFFLOAD_FAIL_NOTIFICATION:
310 br_opt_toggle(br, BROPT_MDB_OFFLOAD_FAIL_NOTIFICATION, on);
311 break;
312 case BR_BOOLOPT_FDB_LOCAL_VLAN_0:
313 err = br_toggle_fdb_local_vlan_0(br, on, extack);
314 break;
315 default:
316 /* shouldn't be called with unsupported options */
317 WARN_ON(1);
318 break;
319 }
320
321 return err;
322 }
323
br_boolopt_get(const struct net_bridge * br,enum br_boolopt_id opt)324 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
325 {
326 switch (opt) {
327 case BR_BOOLOPT_NO_LL_LEARN:
328 return br_opt_get(br, BROPT_NO_LL_LEARN);
329 case BR_BOOLOPT_MCAST_VLAN_SNOOPING:
330 return br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED);
331 case BR_BOOLOPT_MST_ENABLE:
332 return br_opt_get(br, BROPT_MST_ENABLED);
333 case BR_BOOLOPT_MDB_OFFLOAD_FAIL_NOTIFICATION:
334 return br_opt_get(br, BROPT_MDB_OFFLOAD_FAIL_NOTIFICATION);
335 case BR_BOOLOPT_FDB_LOCAL_VLAN_0:
336 return br_opt_get(br, BROPT_FDB_LOCAL_VLAN_0);
337 default:
338 /* shouldn't be called with unsupported options */
339 WARN_ON(1);
340 break;
341 }
342
343 return 0;
344 }
345
br_boolopt_multi_toggle(struct net_bridge * br,struct br_boolopt_multi * bm,struct netlink_ext_ack * extack)346 int br_boolopt_multi_toggle(struct net_bridge *br,
347 struct br_boolopt_multi *bm,
348 struct netlink_ext_ack *extack)
349 {
350 unsigned long bitmap = bm->optmask;
351 int err = 0;
352 int opt_id;
353
354 opt_id = find_next_bit(&bitmap, BITS_PER_LONG, BR_BOOLOPT_MAX);
355 if (opt_id != BITS_PER_LONG) {
356 NL_SET_ERR_MSG_FMT_MOD(extack, "Unknown boolean option %d",
357 opt_id);
358 return -EINVAL;
359 }
360
361 for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
362 bool on = !!(bm->optval & BIT(opt_id));
363
364 err = br_boolopt_toggle(br, opt_id, on, extack);
365 if (err) {
366 br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
367 opt_id, br_boolopt_get(br, opt_id), on, err);
368 break;
369 }
370 }
371
372 return err;
373 }
374
br_boolopt_multi_get(const struct net_bridge * br,struct br_boolopt_multi * bm)375 void br_boolopt_multi_get(const struct net_bridge *br,
376 struct br_boolopt_multi *bm)
377 {
378 u32 optval = 0;
379 int opt_id;
380
381 for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
382 optval |= (br_boolopt_get(br, opt_id) << opt_id);
383
384 bm->optval = optval;
385 bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
386 }
387
388 /* private bridge options, controlled by the kernel */
br_opt_toggle(struct net_bridge * br,enum net_bridge_opts opt,bool on)389 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
390 {
391 bool cur = !!br_opt_get(br, opt);
392
393 br_debug(br, "toggle option: %d state: %d -> %d\n",
394 opt, cur, on);
395
396 if (cur == on)
397 return;
398
399 if (on)
400 set_bit(opt, &br->options);
401 else
402 clear_bit(opt, &br->options);
403 }
404
br_net_exit_rtnl(struct net * net,struct list_head * dev_to_kill)405 static void __net_exit br_net_exit_rtnl(struct net *net,
406 struct list_head *dev_to_kill)
407 {
408 struct net_device *dev;
409
410 ASSERT_RTNL_NET(net);
411
412 for_each_netdev(net, dev)
413 if (netif_is_bridge_master(dev))
414 br_dev_delete(dev, dev_to_kill);
415 }
416
417 static struct pernet_operations br_net_ops = {
418 .exit_rtnl = br_net_exit_rtnl,
419 };
420
421 static const struct stp_proto br_stp_proto = {
422 .rcv = br_stp_rcv,
423 };
424
br_init(void)425 static int __init br_init(void)
426 {
427 int err;
428
429 BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
430
431 err = stp_proto_register(&br_stp_proto);
432 if (err < 0) {
433 pr_err("bridge: can't register sap for STP\n");
434 return err;
435 }
436
437 err = br_fdb_init();
438 if (err)
439 goto err_out;
440
441 err = register_pernet_subsys(&br_net_ops);
442 if (err)
443 goto err_out1;
444
445 err = br_nf_core_init();
446 if (err)
447 goto err_out2;
448
449 err = register_netdevice_notifier(&br_device_notifier);
450 if (err)
451 goto err_out3;
452
453 err = register_switchdev_notifier(&br_switchdev_notifier);
454 if (err)
455 goto err_out4;
456
457 err = register_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
458 if (err)
459 goto err_out5;
460
461 err = br_netlink_init();
462 if (err)
463 goto err_out6;
464
465 brioctl_set(br_ioctl_stub);
466
467 #if IS_ENABLED(CONFIG_ATM_LANE)
468 br_fdb_test_addr_hook = br_fdb_test_addr;
469 #endif
470
471 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
472 pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
473 "by default. Update your scripts to load br_netfilter if you "
474 "need this.\n");
475 #endif
476
477 return 0;
478
479 err_out6:
480 unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
481 err_out5:
482 unregister_switchdev_notifier(&br_switchdev_notifier);
483 err_out4:
484 unregister_netdevice_notifier(&br_device_notifier);
485 err_out3:
486 br_nf_core_fini();
487 err_out2:
488 unregister_pernet_subsys(&br_net_ops);
489 err_out1:
490 br_fdb_fini();
491 err_out:
492 stp_proto_unregister(&br_stp_proto);
493 return err;
494 }
495
br_deinit(void)496 static void __exit br_deinit(void)
497 {
498 stp_proto_unregister(&br_stp_proto);
499 br_netlink_fini();
500 unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
501 unregister_switchdev_notifier(&br_switchdev_notifier);
502 unregister_netdevice_notifier(&br_device_notifier);
503 brioctl_set(NULL);
504 unregister_pernet_subsys(&br_net_ops);
505
506 rcu_barrier(); /* Wait for completion of call_rcu()'s */
507
508 br_nf_core_fini();
509 #if IS_ENABLED(CONFIG_ATM_LANE)
510 br_fdb_test_addr_hook = NULL;
511 #endif
512 br_fdb_fini();
513 }
514
515 module_init(br_init)
516 module_exit(br_deinit)
517 MODULE_LICENSE("GPL");
518 MODULE_VERSION(BR_VERSION);
519 MODULE_ALIAS_RTNL_LINK("bridge");
520 MODULE_DESCRIPTION("Ethernet bridge driver");
521 MODULE_IMPORT_NS("NETDEV_INTERNAL");
522