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