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 /* 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 */
br_switchdev_event(struct notifier_block * unused,unsigned long event,void * ptr)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, 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
196 out:
197 return err;
198 }
199
200 static struct notifier_block br_switchdev_notifier = {
201 .notifier_call = br_switchdev_event,
202 };
203
204 /* called under rtnl_mutex */
br_switchdev_blocking_event(struct notifier_block * nb,unsigned long event,void * ptr)205 static int br_switchdev_blocking_event(struct notifier_block *nb,
206 unsigned long event, void *ptr)
207 {
208 struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(ptr);
209 struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
210 struct switchdev_notifier_brport_info *brport_info;
211 const struct switchdev_brport *b;
212 struct net_bridge_port *p;
213 int err = NOTIFY_DONE;
214
215 p = br_port_get_rtnl(dev);
216 if (!p)
217 goto out;
218
219 switch (event) {
220 case SWITCHDEV_BRPORT_OFFLOADED:
221 brport_info = ptr;
222 b = &brport_info->brport;
223
224 err = br_switchdev_port_offload(p, b->dev, b->ctx,
225 b->atomic_nb, b->blocking_nb,
226 b->tx_fwd_offload, extack);
227 err = notifier_from_errno(err);
228 break;
229 case SWITCHDEV_BRPORT_UNOFFLOADED:
230 brport_info = ptr;
231 b = &brport_info->brport;
232
233 br_switchdev_port_unoffload(p, b->ctx, b->atomic_nb,
234 b->blocking_nb);
235 break;
236 }
237
238 out:
239 return err;
240 }
241
242 static struct notifier_block br_switchdev_blocking_notifier = {
243 .notifier_call = br_switchdev_blocking_event,
244 };
245
246 /* br_boolopt_toggle - change user-controlled boolean option
247 *
248 * @br: bridge device
249 * @opt: id of the option to change
250 * @on: new option value
251 * @extack: extack for error messages
252 *
253 * Changes the value of the respective boolean option to @on taking care of
254 * any internal option value mapping and configuration.
255 */
br_boolopt_toggle(struct net_bridge * br,enum br_boolopt_id opt,bool on,struct netlink_ext_ack * extack)256 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
257 struct netlink_ext_ack *extack)
258 {
259 int err = 0;
260
261 switch (opt) {
262 case BR_BOOLOPT_NO_LL_LEARN:
263 br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
264 break;
265 case BR_BOOLOPT_MCAST_VLAN_SNOOPING:
266 err = br_multicast_toggle_vlan_snooping(br, on, extack);
267 break;
268 case BR_BOOLOPT_MST_ENABLE:
269 err = br_mst_set_enabled(br, on, extack);
270 break;
271 default:
272 /* shouldn't be called with unsupported options */
273 WARN_ON(1);
274 break;
275 }
276
277 return err;
278 }
279
br_boolopt_get(const struct net_bridge * br,enum br_boolopt_id opt)280 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
281 {
282 switch (opt) {
283 case BR_BOOLOPT_NO_LL_LEARN:
284 return br_opt_get(br, BROPT_NO_LL_LEARN);
285 case BR_BOOLOPT_MCAST_VLAN_SNOOPING:
286 return br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED);
287 case BR_BOOLOPT_MST_ENABLE:
288 return br_opt_get(br, BROPT_MST_ENABLED);
289 default:
290 /* shouldn't be called with unsupported options */
291 WARN_ON(1);
292 break;
293 }
294
295 return 0;
296 }
297
br_boolopt_multi_toggle(struct net_bridge * br,struct br_boolopt_multi * bm,struct netlink_ext_ack * extack)298 int br_boolopt_multi_toggle(struct net_bridge *br,
299 struct br_boolopt_multi *bm,
300 struct netlink_ext_ack *extack)
301 {
302 unsigned long bitmap = bm->optmask;
303 int err = 0;
304 int opt_id;
305
306 for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
307 bool on = !!(bm->optval & BIT(opt_id));
308
309 err = br_boolopt_toggle(br, opt_id, on, extack);
310 if (err) {
311 br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
312 opt_id, br_boolopt_get(br, opt_id), on, err);
313 break;
314 }
315 }
316
317 return err;
318 }
319
br_boolopt_multi_get(const struct net_bridge * br,struct br_boolopt_multi * bm)320 void br_boolopt_multi_get(const struct net_bridge *br,
321 struct br_boolopt_multi *bm)
322 {
323 u32 optval = 0;
324 int opt_id;
325
326 for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
327 optval |= (br_boolopt_get(br, opt_id) << opt_id);
328
329 bm->optval = optval;
330 bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
331 }
332
333 /* private bridge options, controlled by the kernel */
br_opt_toggle(struct net_bridge * br,enum net_bridge_opts opt,bool on)334 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
335 {
336 bool cur = !!br_opt_get(br, opt);
337
338 br_debug(br, "toggle option: %d state: %d -> %d\n",
339 opt, cur, on);
340
341 if (cur == on)
342 return;
343
344 if (on)
345 set_bit(opt, &br->options);
346 else
347 clear_bit(opt, &br->options);
348 }
349
br_net_exit_batch(struct list_head * net_list)350 static void __net_exit br_net_exit_batch(struct list_head *net_list)
351 {
352 struct net_device *dev;
353 struct net *net;
354 LIST_HEAD(list);
355
356 rtnl_lock();
357
358 list_for_each_entry(net, net_list, exit_list)
359 for_each_netdev(net, dev)
360 if (netif_is_bridge_master(dev))
361 br_dev_delete(dev, &list);
362
363 unregister_netdevice_many(&list);
364
365 rtnl_unlock();
366 }
367
368 static struct pernet_operations br_net_ops = {
369 .exit_batch = br_net_exit_batch,
370 };
371
372 static const struct stp_proto br_stp_proto = {
373 .rcv = br_stp_rcv,
374 };
375
br_init(void)376 static int __init br_init(void)
377 {
378 int err;
379
380 BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
381
382 err = stp_proto_register(&br_stp_proto);
383 if (err < 0) {
384 pr_err("bridge: can't register sap for STP\n");
385 return err;
386 }
387
388 err = br_fdb_init();
389 if (err)
390 goto err_out;
391
392 err = register_pernet_subsys(&br_net_ops);
393 if (err)
394 goto err_out1;
395
396 err = br_nf_core_init();
397 if (err)
398 goto err_out2;
399
400 err = register_netdevice_notifier(&br_device_notifier);
401 if (err)
402 goto err_out3;
403
404 err = register_switchdev_notifier(&br_switchdev_notifier);
405 if (err)
406 goto err_out4;
407
408 err = register_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
409 if (err)
410 goto err_out5;
411
412 err = br_netlink_init();
413 if (err)
414 goto err_out6;
415
416 brioctl_set(br_ioctl_stub);
417
418 #if IS_ENABLED(CONFIG_ATM_LANE)
419 br_fdb_test_addr_hook = br_fdb_test_addr;
420 #endif
421
422 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
423 pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
424 "by default. Update your scripts to load br_netfilter if you "
425 "need this.\n");
426 #endif
427
428 return 0;
429
430 err_out6:
431 unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
432 err_out5:
433 unregister_switchdev_notifier(&br_switchdev_notifier);
434 err_out4:
435 unregister_netdevice_notifier(&br_device_notifier);
436 err_out3:
437 br_nf_core_fini();
438 err_out2:
439 unregister_pernet_subsys(&br_net_ops);
440 err_out1:
441 br_fdb_fini();
442 err_out:
443 stp_proto_unregister(&br_stp_proto);
444 return err;
445 }
446
br_deinit(void)447 static void __exit br_deinit(void)
448 {
449 stp_proto_unregister(&br_stp_proto);
450 br_netlink_fini();
451 unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
452 unregister_switchdev_notifier(&br_switchdev_notifier);
453 unregister_netdevice_notifier(&br_device_notifier);
454 brioctl_set(NULL);
455 unregister_pernet_subsys(&br_net_ops);
456
457 rcu_barrier(); /* Wait for completion of call_rcu()'s */
458
459 br_nf_core_fini();
460 #if IS_ENABLED(CONFIG_ATM_LANE)
461 br_fdb_test_addr_hook = NULL;
462 #endif
463 br_fdb_fini();
464 }
465
466 module_init(br_init)
467 module_exit(br_deinit)
468 MODULE_LICENSE("GPL");
469 MODULE_VERSION(BR_VERSION);
470 MODULE_ALIAS_RTNL_LINK("bridge");
471