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 underlaying 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 /* br_boolopt_toggle - change user-controlled boolean option
205 *
206 * @br: bridge device
207 * @opt: id of the option to change
208 * @on: new option value
209 * @extack: extack for error messages
210 *
211 * Changes the value of the respective boolean option to @on taking care of
212 * any internal option value mapping and configuration.
213 */
br_boolopt_toggle(struct net_bridge * br,enum br_boolopt_id opt,bool on,struct netlink_ext_ack * extack)214 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
215 struct netlink_ext_ack *extack)
216 {
217 switch (opt) {
218 case BR_BOOLOPT_NO_LL_LEARN:
219 br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
220 break;
221 default:
222 /* shouldn't be called with unsupported options */
223 WARN_ON(1);
224 break;
225 }
226
227 return 0;
228 }
229
br_boolopt_get(const struct net_bridge * br,enum br_boolopt_id opt)230 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
231 {
232 switch (opt) {
233 case BR_BOOLOPT_NO_LL_LEARN:
234 return br_opt_get(br, BROPT_NO_LL_LEARN);
235 default:
236 /* shouldn't be called with unsupported options */
237 WARN_ON(1);
238 break;
239 }
240
241 return 0;
242 }
243
br_boolopt_multi_toggle(struct net_bridge * br,struct br_boolopt_multi * bm,struct netlink_ext_ack * extack)244 int br_boolopt_multi_toggle(struct net_bridge *br,
245 struct br_boolopt_multi *bm,
246 struct netlink_ext_ack *extack)
247 {
248 unsigned long bitmap = bm->optmask;
249 int err = 0;
250 int opt_id;
251
252 for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
253 bool on = !!(bm->optval & BIT(opt_id));
254
255 err = br_boolopt_toggle(br, opt_id, on, extack);
256 if (err) {
257 br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
258 opt_id, br_boolopt_get(br, opt_id), on, err);
259 break;
260 }
261 }
262
263 return err;
264 }
265
br_boolopt_multi_get(const struct net_bridge * br,struct br_boolopt_multi * bm)266 void br_boolopt_multi_get(const struct net_bridge *br,
267 struct br_boolopt_multi *bm)
268 {
269 u32 optval = 0;
270 int opt_id;
271
272 for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
273 optval |= (br_boolopt_get(br, opt_id) << opt_id);
274
275 bm->optval = optval;
276 bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
277 }
278
279 /* private bridge options, controlled by the kernel */
br_opt_toggle(struct net_bridge * br,enum net_bridge_opts opt,bool on)280 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
281 {
282 bool cur = !!br_opt_get(br, opt);
283
284 br_debug(br, "toggle option: %d state: %d -> %d\n",
285 opt, cur, on);
286
287 if (cur == on)
288 return;
289
290 if (on)
291 set_bit(opt, &br->options);
292 else
293 clear_bit(opt, &br->options);
294 }
295
br_net_exit(struct net * net)296 static void __net_exit br_net_exit(struct net *net)
297 {
298 struct net_device *dev;
299 LIST_HEAD(list);
300
301 rtnl_lock();
302 for_each_netdev(net, dev)
303 if (dev->priv_flags & IFF_EBRIDGE)
304 br_dev_delete(dev, &list);
305
306 unregister_netdevice_many(&list);
307 rtnl_unlock();
308
309 }
310
311 static struct pernet_operations br_net_ops = {
312 .exit = br_net_exit,
313 };
314
315 static const struct stp_proto br_stp_proto = {
316 .rcv = br_stp_rcv,
317 };
318
br_init(void)319 static int __init br_init(void)
320 {
321 int err;
322
323 BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
324
325 err = stp_proto_register(&br_stp_proto);
326 if (err < 0) {
327 pr_err("bridge: can't register sap for STP\n");
328 return err;
329 }
330
331 err = br_fdb_init();
332 if (err)
333 goto err_out;
334
335 err = register_pernet_subsys(&br_net_ops);
336 if (err)
337 goto err_out1;
338
339 err = br_nf_core_init();
340 if (err)
341 goto err_out2;
342
343 err = register_netdevice_notifier(&br_device_notifier);
344 if (err)
345 goto err_out3;
346
347 err = register_switchdev_notifier(&br_switchdev_notifier);
348 if (err)
349 goto err_out4;
350
351 err = br_netlink_init();
352 if (err)
353 goto err_out5;
354
355 brioctl_set(br_ioctl_deviceless_stub);
356
357 #if IS_ENABLED(CONFIG_ATM_LANE)
358 br_fdb_test_addr_hook = br_fdb_test_addr;
359 #endif
360
361 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
362 pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
363 "by default. Update your scripts to load br_netfilter if you "
364 "need this.\n");
365 #endif
366
367 return 0;
368
369 err_out5:
370 unregister_switchdev_notifier(&br_switchdev_notifier);
371 err_out4:
372 unregister_netdevice_notifier(&br_device_notifier);
373 err_out3:
374 br_nf_core_fini();
375 err_out2:
376 unregister_pernet_subsys(&br_net_ops);
377 err_out1:
378 br_fdb_fini();
379 err_out:
380 stp_proto_unregister(&br_stp_proto);
381 return err;
382 }
383
br_deinit(void)384 static void __exit br_deinit(void)
385 {
386 stp_proto_unregister(&br_stp_proto);
387 br_netlink_fini();
388 unregister_switchdev_notifier(&br_switchdev_notifier);
389 unregister_netdevice_notifier(&br_device_notifier);
390 brioctl_set(NULL);
391 unregister_pernet_subsys(&br_net_ops);
392
393 rcu_barrier(); /* Wait for completion of call_rcu()'s */
394
395 br_nf_core_fini();
396 #if IS_ENABLED(CONFIG_ATM_LANE)
397 br_fdb_test_addr_hook = NULL;
398 #endif
399 br_fdb_fini();
400 }
401
402 module_init(br_init)
403 module_exit(br_deinit)
404 MODULE_LICENSE("GPL");
405 MODULE_VERSION(BR_VERSION);
406 MODULE_ALIAS_RTNL_LINK("bridge");
407