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 (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, ¬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 default:
269 /* shouldn't be called with unsupported options */
270 WARN_ON(1);
271 break;
272 }
273
274 return err;
275 }
276
br_boolopt_get(const struct net_bridge * br,enum br_boolopt_id opt)277 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
278 {
279 switch (opt) {
280 case BR_BOOLOPT_NO_LL_LEARN:
281 return br_opt_get(br, BROPT_NO_LL_LEARN);
282 case BR_BOOLOPT_MCAST_VLAN_SNOOPING:
283 return br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED);
284 default:
285 /* shouldn't be called with unsupported options */
286 WARN_ON(1);
287 break;
288 }
289
290 return 0;
291 }
292
br_boolopt_multi_toggle(struct net_bridge * br,struct br_boolopt_multi * bm,struct netlink_ext_ack * extack)293 int br_boolopt_multi_toggle(struct net_bridge *br,
294 struct br_boolopt_multi *bm,
295 struct netlink_ext_ack *extack)
296 {
297 unsigned long bitmap = bm->optmask;
298 int err = 0;
299 int opt_id;
300
301 for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
302 bool on = !!(bm->optval & BIT(opt_id));
303
304 err = br_boolopt_toggle(br, opt_id, on, extack);
305 if (err) {
306 br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
307 opt_id, br_boolopt_get(br, opt_id), on, err);
308 break;
309 }
310 }
311
312 return err;
313 }
314
br_boolopt_multi_get(const struct net_bridge * br,struct br_boolopt_multi * bm)315 void br_boolopt_multi_get(const struct net_bridge *br,
316 struct br_boolopt_multi *bm)
317 {
318 u32 optval = 0;
319 int opt_id;
320
321 for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
322 optval |= (br_boolopt_get(br, opt_id) << opt_id);
323
324 bm->optval = optval;
325 bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
326 }
327
328 /* private bridge options, controlled by the kernel */
br_opt_toggle(struct net_bridge * br,enum net_bridge_opts opt,bool on)329 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
330 {
331 bool cur = !!br_opt_get(br, opt);
332
333 br_debug(br, "toggle option: %d state: %d -> %d\n",
334 opt, cur, on);
335
336 if (cur == on)
337 return;
338
339 if (on)
340 set_bit(opt, &br->options);
341 else
342 clear_bit(opt, &br->options);
343 }
344
br_net_exit(struct net * net)345 static void __net_exit br_net_exit(struct net *net)
346 {
347 struct net_device *dev;
348 LIST_HEAD(list);
349
350 rtnl_lock();
351 for_each_netdev(net, dev)
352 if (dev->priv_flags & IFF_EBRIDGE)
353 br_dev_delete(dev, &list);
354
355 unregister_netdevice_many(&list);
356 rtnl_unlock();
357
358 }
359
360 static struct pernet_operations br_net_ops = {
361 .exit = br_net_exit,
362 };
363
364 static const struct stp_proto br_stp_proto = {
365 .rcv = br_stp_rcv,
366 };
367
br_init(void)368 static int __init br_init(void)
369 {
370 int err;
371
372 BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
373
374 err = stp_proto_register(&br_stp_proto);
375 if (err < 0) {
376 pr_err("bridge: can't register sap for STP\n");
377 return err;
378 }
379
380 err = br_fdb_init();
381 if (err)
382 goto err_out;
383
384 err = register_pernet_subsys(&br_net_ops);
385 if (err)
386 goto err_out1;
387
388 err = br_nf_core_init();
389 if (err)
390 goto err_out2;
391
392 err = register_netdevice_notifier(&br_device_notifier);
393 if (err)
394 goto err_out3;
395
396 err = register_switchdev_notifier(&br_switchdev_notifier);
397 if (err)
398 goto err_out4;
399
400 err = register_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
401 if (err)
402 goto err_out5;
403
404 err = br_netlink_init();
405 if (err)
406 goto err_out6;
407
408 brioctl_set(br_ioctl_stub);
409
410 #if IS_ENABLED(CONFIG_ATM_LANE)
411 br_fdb_test_addr_hook = br_fdb_test_addr;
412 #endif
413
414 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
415 pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
416 "by default. Update your scripts to load br_netfilter if you "
417 "need this.\n");
418 #endif
419
420 return 0;
421
422 err_out6:
423 unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
424 err_out5:
425 unregister_switchdev_notifier(&br_switchdev_notifier);
426 err_out4:
427 unregister_netdevice_notifier(&br_device_notifier);
428 err_out3:
429 br_nf_core_fini();
430 err_out2:
431 unregister_pernet_subsys(&br_net_ops);
432 err_out1:
433 br_fdb_fini();
434 err_out:
435 stp_proto_unregister(&br_stp_proto);
436 return err;
437 }
438
br_deinit(void)439 static void __exit br_deinit(void)
440 {
441 stp_proto_unregister(&br_stp_proto);
442 br_netlink_fini();
443 unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
444 unregister_switchdev_notifier(&br_switchdev_notifier);
445 unregister_netdevice_notifier(&br_device_notifier);
446 brioctl_set(NULL);
447 unregister_pernet_subsys(&br_net_ops);
448
449 rcu_barrier(); /* Wait for completion of call_rcu()'s */
450
451 br_nf_core_fini();
452 #if IS_ENABLED(CONFIG_ATM_LANE)
453 br_fdb_test_addr_hook = NULL;
454 #endif
455 br_fdb_fini();
456 }
457
458 module_init(br_init)
459 module_exit(br_deinit)
460 MODULE_LICENSE("GPL");
461 MODULE_VERSION(BR_VERSION);
462 MODULE_ALIAS_RTNL_LINK("bridge");
463