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 br_sysfs_addbr(dev);
47 return NOTIFY_DONE;
48 }
49 }
50
51 /* not a port of a bridge */
52 p = br_port_get_rtnl(dev);
53 if (!p)
54 return NOTIFY_DONE;
55
56 br = p->br;
57
58 switch (event) {
59 case NETDEV_CHANGEMTU:
60 br_mtu_auto_adjust(br);
61 break;
62
63 case NETDEV_PRE_CHANGEADDR:
64 if (br->dev->addr_assign_type == NET_ADDR_SET)
65 break;
66 prechaddr_info = ptr;
67 err = dev_pre_changeaddr_notify(br->dev,
68 prechaddr_info->dev_addr,
69 extack);
70 if (err)
71 return notifier_from_errno(err);
72 break;
73
74 case NETDEV_CHANGEADDR:
75 spin_lock_bh(&br->lock);
76 br_fdb_changeaddr(p, dev->dev_addr);
77 changed_addr = br_stp_recalculate_bridge_id(br);
78 spin_unlock_bh(&br->lock);
79
80 if (changed_addr)
81 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
82
83 break;
84
85 case NETDEV_CHANGE:
86 br_port_carrier_check(p, ¬ified);
87 break;
88
89 case NETDEV_FEAT_CHANGE:
90 netdev_update_features(br->dev);
91 break;
92
93 case NETDEV_DOWN:
94 spin_lock_bh(&br->lock);
95 if (br->dev->flags & IFF_UP) {
96 br_stp_disable_port(p);
97 notified = true;
98 }
99 spin_unlock_bh(&br->lock);
100 break;
101
102 case NETDEV_UP:
103 if (netif_running(br->dev) && netif_oper_up(dev)) {
104 spin_lock_bh(&br->lock);
105 br_stp_enable_port(p);
106 notified = true;
107 spin_unlock_bh(&br->lock);
108 }
109 break;
110
111 case NETDEV_UNREGISTER:
112 br_del_if(br, dev);
113 break;
114
115 case NETDEV_CHANGENAME:
116 err = br_sysfs_renameif(p);
117 if (err)
118 return notifier_from_errno(err);
119 break;
120
121 case NETDEV_PRE_TYPE_CHANGE:
122 /* Forbid underlaying device to change its type. */
123 return NOTIFY_BAD;
124
125 case NETDEV_RESEND_IGMP:
126 /* Propagate to master device */
127 call_netdevice_notifiers(event, br->dev);
128 break;
129 }
130
131 if (event != NETDEV_UNREGISTER)
132 br_vlan_port_event(p, event);
133
134 /* Events that may cause spanning tree to refresh */
135 if (!notified && (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
136 event == NETDEV_CHANGE || event == NETDEV_DOWN))
137 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
138
139 return NOTIFY_DONE;
140 }
141
142 static struct notifier_block br_device_notifier = {
143 .notifier_call = br_device_event
144 };
145
146 /* called with RTNL or RCU */
br_switchdev_event(struct notifier_block * unused,unsigned long event,void * ptr)147 static int br_switchdev_event(struct notifier_block *unused,
148 unsigned long event, void *ptr)
149 {
150 struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
151 struct net_bridge_port *p;
152 struct net_bridge *br;
153 struct switchdev_notifier_fdb_info *fdb_info;
154 int err = NOTIFY_DONE;
155
156 p = br_port_get_rtnl_rcu(dev);
157 if (!p)
158 goto out;
159
160 br = p->br;
161
162 switch (event) {
163 case SWITCHDEV_FDB_ADD_TO_BRIDGE:
164 fdb_info = ptr;
165 err = br_fdb_external_learn_add(br, p, fdb_info->addr,
166 fdb_info->vid, false);
167 if (err) {
168 err = notifier_from_errno(err);
169 break;
170 }
171 br_fdb_offloaded_set(br, p, fdb_info->addr,
172 fdb_info->vid, true);
173 break;
174 case SWITCHDEV_FDB_DEL_TO_BRIDGE:
175 fdb_info = ptr;
176 err = br_fdb_external_learn_del(br, p, fdb_info->addr,
177 fdb_info->vid, false);
178 if (err)
179 err = notifier_from_errno(err);
180 break;
181 case SWITCHDEV_FDB_OFFLOADED:
182 fdb_info = ptr;
183 br_fdb_offloaded_set(br, p, fdb_info->addr,
184 fdb_info->vid, fdb_info->offloaded);
185 break;
186 case SWITCHDEV_FDB_FLUSH_TO_BRIDGE:
187 fdb_info = ptr;
188 /* Don't delete static entries */
189 br_fdb_delete_by_port(br, p, fdb_info->vid, 0);
190 break;
191 }
192
193 out:
194 return err;
195 }
196
197 static struct notifier_block br_switchdev_notifier = {
198 .notifier_call = br_switchdev_event,
199 };
200
201 /* br_boolopt_toggle - change user-controlled boolean option
202 *
203 * @br: bridge device
204 * @opt: id of the option to change
205 * @on: new option value
206 * @extack: extack for error messages
207 *
208 * Changes the value of the respective boolean option to @on taking care of
209 * any internal option value mapping and configuration.
210 */
br_boolopt_toggle(struct net_bridge * br,enum br_boolopt_id opt,bool on,struct netlink_ext_ack * extack)211 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
212 struct netlink_ext_ack *extack)
213 {
214 switch (opt) {
215 case BR_BOOLOPT_NO_LL_LEARN:
216 br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
217 break;
218 default:
219 /* shouldn't be called with unsupported options */
220 WARN_ON(1);
221 break;
222 }
223
224 return 0;
225 }
226
br_boolopt_get(const struct net_bridge * br,enum br_boolopt_id opt)227 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
228 {
229 switch (opt) {
230 case BR_BOOLOPT_NO_LL_LEARN:
231 return br_opt_get(br, BROPT_NO_LL_LEARN);
232 default:
233 /* shouldn't be called with unsupported options */
234 WARN_ON(1);
235 break;
236 }
237
238 return 0;
239 }
240
br_boolopt_multi_toggle(struct net_bridge * br,struct br_boolopt_multi * bm,struct netlink_ext_ack * extack)241 int br_boolopt_multi_toggle(struct net_bridge *br,
242 struct br_boolopt_multi *bm,
243 struct netlink_ext_ack *extack)
244 {
245 unsigned long bitmap = bm->optmask;
246 int err = 0;
247 int opt_id;
248
249 for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
250 bool on = !!(bm->optval & BIT(opt_id));
251
252 err = br_boolopt_toggle(br, opt_id, on, extack);
253 if (err) {
254 br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
255 opt_id, br_boolopt_get(br, opt_id), on, err);
256 break;
257 }
258 }
259
260 return err;
261 }
262
br_boolopt_multi_get(const struct net_bridge * br,struct br_boolopt_multi * bm)263 void br_boolopt_multi_get(const struct net_bridge *br,
264 struct br_boolopt_multi *bm)
265 {
266 u32 optval = 0;
267 int opt_id;
268
269 for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
270 optval |= (br_boolopt_get(br, opt_id) << opt_id);
271
272 bm->optval = optval;
273 bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
274 }
275
276 /* private bridge options, controlled by the kernel */
br_opt_toggle(struct net_bridge * br,enum net_bridge_opts opt,bool on)277 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
278 {
279 bool cur = !!br_opt_get(br, opt);
280
281 br_debug(br, "toggle option: %d state: %d -> %d\n",
282 opt, cur, on);
283
284 if (cur == on)
285 return;
286
287 if (on)
288 set_bit(opt, &br->options);
289 else
290 clear_bit(opt, &br->options);
291 }
292
br_net_exit(struct net * net)293 static void __net_exit br_net_exit(struct net *net)
294 {
295 struct net_device *dev;
296 LIST_HEAD(list);
297
298 rtnl_lock();
299 for_each_netdev(net, dev)
300 if (dev->priv_flags & IFF_EBRIDGE)
301 br_dev_delete(dev, &list);
302
303 unregister_netdevice_many(&list);
304 rtnl_unlock();
305
306 }
307
308 static struct pernet_operations br_net_ops = {
309 .exit = br_net_exit,
310 };
311
312 static const struct stp_proto br_stp_proto = {
313 .rcv = br_stp_rcv,
314 };
315
br_init(void)316 static int __init br_init(void)
317 {
318 int err;
319
320 BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
321
322 err = stp_proto_register(&br_stp_proto);
323 if (err < 0) {
324 pr_err("bridge: can't register sap for STP\n");
325 return err;
326 }
327
328 err = br_fdb_init();
329 if (err)
330 goto err_out;
331
332 err = register_pernet_subsys(&br_net_ops);
333 if (err)
334 goto err_out1;
335
336 err = br_nf_core_init();
337 if (err)
338 goto err_out2;
339
340 err = register_netdevice_notifier(&br_device_notifier);
341 if (err)
342 goto err_out3;
343
344 err = register_switchdev_notifier(&br_switchdev_notifier);
345 if (err)
346 goto err_out4;
347
348 err = br_netlink_init();
349 if (err)
350 goto err_out5;
351
352 brioctl_set(br_ioctl_deviceless_stub);
353
354 #if IS_ENABLED(CONFIG_ATM_LANE)
355 br_fdb_test_addr_hook = br_fdb_test_addr;
356 #endif
357
358 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
359 pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
360 "by default. Update your scripts to load br_netfilter if you "
361 "need this.\n");
362 #endif
363
364 return 0;
365
366 err_out5:
367 unregister_switchdev_notifier(&br_switchdev_notifier);
368 err_out4:
369 unregister_netdevice_notifier(&br_device_notifier);
370 err_out3:
371 br_nf_core_fini();
372 err_out2:
373 unregister_pernet_subsys(&br_net_ops);
374 err_out1:
375 br_fdb_fini();
376 err_out:
377 stp_proto_unregister(&br_stp_proto);
378 return err;
379 }
380
br_deinit(void)381 static void __exit br_deinit(void)
382 {
383 stp_proto_unregister(&br_stp_proto);
384 br_netlink_fini();
385 unregister_switchdev_notifier(&br_switchdev_notifier);
386 unregister_netdevice_notifier(&br_device_notifier);
387 brioctl_set(NULL);
388 unregister_pernet_subsys(&br_net_ops);
389
390 rcu_barrier(); /* Wait for completion of call_rcu()'s */
391
392 br_nf_core_fini();
393 #if IS_ENABLED(CONFIG_ATM_LANE)
394 br_fdb_test_addr_hook = NULL;
395 #endif
396 br_fdb_fini();
397 }
398
399 module_init(br_init)
400 module_exit(br_deinit)
401 MODULE_LICENSE("GPL");
402 MODULE_VERSION(BR_VERSION);
403 MODULE_ALIAS_RTNL_LINK("bridge");
404
