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 }
187
188 out:
189 return err;
190 }
191
192 static struct notifier_block br_switchdev_notifier = {
193 .notifier_call = br_switchdev_event,
194 };
195
196 /* br_boolopt_toggle - change user-controlled boolean option
197 *
198 * @br: bridge device
199 * @opt: id of the option to change
200 * @on: new option value
201 * @extack: extack for error messages
202 *
203 * Changes the value of the respective boolean option to @on taking care of
204 * any internal option value mapping and configuration.
205 */
br_boolopt_toggle(struct net_bridge * br,enum br_boolopt_id opt,bool on,struct netlink_ext_ack * extack)206 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
207 struct netlink_ext_ack *extack)
208 {
209 switch (opt) {
210 case BR_BOOLOPT_NO_LL_LEARN:
211 br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
212 break;
213 default:
214 /* shouldn't be called with unsupported options */
215 WARN_ON(1);
216 break;
217 }
218
219 return 0;
220 }
221
br_boolopt_get(const struct net_bridge * br,enum br_boolopt_id opt)222 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
223 {
224 switch (opt) {
225 case BR_BOOLOPT_NO_LL_LEARN:
226 return br_opt_get(br, BROPT_NO_LL_LEARN);
227 default:
228 /* shouldn't be called with unsupported options */
229 WARN_ON(1);
230 break;
231 }
232
233 return 0;
234 }
235
br_boolopt_multi_toggle(struct net_bridge * br,struct br_boolopt_multi * bm,struct netlink_ext_ack * extack)236 int br_boolopt_multi_toggle(struct net_bridge *br,
237 struct br_boolopt_multi *bm,
238 struct netlink_ext_ack *extack)
239 {
240 unsigned long bitmap = bm->optmask;
241 int err = 0;
242 int opt_id;
243
244 for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
245 bool on = !!(bm->optval & BIT(opt_id));
246
247 err = br_boolopt_toggle(br, opt_id, on, extack);
248 if (err) {
249 br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
250 opt_id, br_boolopt_get(br, opt_id), on, err);
251 break;
252 }
253 }
254
255 return err;
256 }
257
br_boolopt_multi_get(const struct net_bridge * br,struct br_boolopt_multi * bm)258 void br_boolopt_multi_get(const struct net_bridge *br,
259 struct br_boolopt_multi *bm)
260 {
261 u32 optval = 0;
262 int opt_id;
263
264 for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
265 optval |= (br_boolopt_get(br, opt_id) << opt_id);
266
267 bm->optval = optval;
268 bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
269 }
270
271 /* private bridge options, controlled by the kernel */
br_opt_toggle(struct net_bridge * br,enum net_bridge_opts opt,bool on)272 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
273 {
274 bool cur = !!br_opt_get(br, opt);
275
276 br_debug(br, "toggle option: %d state: %d -> %d\n",
277 opt, cur, on);
278
279 if (cur == on)
280 return;
281
282 if (on)
283 set_bit(opt, &br->options);
284 else
285 clear_bit(opt, &br->options);
286 }
287
br_net_exit(struct net * net)288 static void __net_exit br_net_exit(struct net *net)
289 {
290 struct net_device *dev;
291 LIST_HEAD(list);
292
293 rtnl_lock();
294 for_each_netdev(net, dev)
295 if (dev->priv_flags & IFF_EBRIDGE)
296 br_dev_delete(dev, &list);
297
298 unregister_netdevice_many(&list);
299 rtnl_unlock();
300
301 }
302
303 static struct pernet_operations br_net_ops = {
304 .exit = br_net_exit,
305 };
306
307 static const struct stp_proto br_stp_proto = {
308 .rcv = br_stp_rcv,
309 };
310
br_init(void)311 static int __init br_init(void)
312 {
313 int err;
314
315 BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));
316
317 err = stp_proto_register(&br_stp_proto);
318 if (err < 0) {
319 pr_err("bridge: can't register sap for STP\n");
320 return err;
321 }
322
323 err = br_fdb_init();
324 if (err)
325 goto err_out;
326
327 err = register_pernet_subsys(&br_net_ops);
328 if (err)
329 goto err_out1;
330
331 err = br_nf_core_init();
332 if (err)
333 goto err_out2;
334
335 err = register_netdevice_notifier(&br_device_notifier);
336 if (err)
337 goto err_out3;
338
339 err = register_switchdev_notifier(&br_switchdev_notifier);
340 if (err)
341 goto err_out4;
342
343 err = br_netlink_init();
344 if (err)
345 goto err_out5;
346
347 brioctl_set(br_ioctl_deviceless_stub);
348
349 #if IS_ENABLED(CONFIG_ATM_LANE)
350 br_fdb_test_addr_hook = br_fdb_test_addr;
351 #endif
352
353 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
354 pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
355 "by default. Update your scripts to load br_netfilter if you "
356 "need this.\n");
357 #endif
358
359 return 0;
360
361 err_out5:
362 unregister_switchdev_notifier(&br_switchdev_notifier);
363 err_out4:
364 unregister_netdevice_notifier(&br_device_notifier);
365 err_out3:
366 br_nf_core_fini();
367 err_out2:
368 unregister_pernet_subsys(&br_net_ops);
369 err_out1:
370 br_fdb_fini();
371 err_out:
372 stp_proto_unregister(&br_stp_proto);
373 return err;
374 }
375
br_deinit(void)376 static void __exit br_deinit(void)
377 {
378 stp_proto_unregister(&br_stp_proto);
379 br_netlink_fini();
380 unregister_switchdev_notifier(&br_switchdev_notifier);
381 unregister_netdevice_notifier(&br_device_notifier);
382 brioctl_set(NULL);
383 unregister_pernet_subsys(&br_net_ops);
384
385 rcu_barrier(); /* Wait for completion of call_rcu()'s */
386
387 br_nf_core_fini();
388 #if IS_ENABLED(CONFIG_ATM_LANE)
389 br_fdb_test_addr_hook = NULL;
390 #endif
391 br_fdb_fini();
392 }
393
394 module_init(br_init)
395 module_exit(br_deinit)
396 MODULE_LICENSE("GPL");
397 MODULE_VERSION(BR_VERSION);
398 MODULE_ALIAS_RTNL_LINK("bridge");
399
