1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Device handling code
4 * Linux ethernet bridge
5 *
6 * Authors:
7 * Lennert Buytenhek <buytenh@gnu.org>
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/netdevice.h>
12 #include <linux/netpoll.h>
13 #include <linux/etherdevice.h>
14 #include <linux/ethtool.h>
15 #include <linux/list.h>
16 #include <linux/netfilter_bridge.h>
17
18 #include <linux/uaccess.h>
19 #include "br_private.h"
20
21 #define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \
22 NETIF_F_GSO_MASK | NETIF_F_HW_CSUM)
23
24 const struct nf_br_ops __rcu *nf_br_ops __read_mostly;
25 EXPORT_SYMBOL_GPL(nf_br_ops);
26
27 /* net device transmit always called with BH disabled */
br_dev_xmit(struct sk_buff * skb,struct net_device * dev)28 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
29 {
30 enum skb_drop_reason reason = pskb_may_pull_reason(skb, ETH_HLEN);
31 struct net_bridge_mcast_port *pmctx_null = NULL;
32 struct net_bridge *br = netdev_priv(dev);
33 struct net_bridge_mcast *brmctx = &br->multicast_ctx;
34 struct net_bridge_fdb_entry *dst;
35 struct net_bridge_mdb_entry *mdst;
36 const struct nf_br_ops *nf_ops;
37 u8 state = BR_STATE_FORWARDING;
38 struct net_bridge_vlan *vlan;
39 const unsigned char *dest;
40 u16 vid = 0;
41
42 if (unlikely(reason != SKB_NOT_DROPPED_YET)) {
43 kfree_skb_reason(skb, reason);
44 return NETDEV_TX_OK;
45 }
46
47 memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
48 br_tc_skb_miss_set(skb, false);
49
50 rcu_read_lock();
51 nf_ops = rcu_dereference(nf_br_ops);
52 if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
53 rcu_read_unlock();
54 return NETDEV_TX_OK;
55 }
56
57 dev_sw_netstats_tx_add(dev, 1, skb->len);
58
59 br_switchdev_frame_unmark(skb);
60 BR_INPUT_SKB_CB(skb)->brdev = dev;
61 BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
62
63 skb_reset_mac_header(skb);
64 skb_pull(skb, ETH_HLEN);
65
66 if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid,
67 &state, &vlan))
68 goto out;
69
70 if (IS_ENABLED(CONFIG_INET) &&
71 (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) ||
72 eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) &&
73 br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
74 br_do_proxy_suppress_arp(skb, br, vid, NULL);
75 } else if (IS_ENABLED(CONFIG_IPV6) &&
76 skb->protocol == htons(ETH_P_IPV6) &&
77 br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
78 pskb_may_pull(skb, sizeof(struct ipv6hdr) +
79 sizeof(struct nd_msg)) &&
80 ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
81 struct nd_msg *msg, _msg;
82
83 msg = br_is_nd_neigh_msg(skb, &_msg);
84 if (msg)
85 br_do_suppress_nd(skb, br, vid, NULL, msg);
86 }
87
88 dest = eth_hdr(skb)->h_dest;
89 if (is_broadcast_ether_addr(dest)) {
90 br_flood(br, skb, BR_PKT_BROADCAST, false, true, vid);
91 } else if (is_multicast_ether_addr(dest)) {
92 if (unlikely(netpoll_tx_running(dev))) {
93 br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid);
94 goto out;
95 }
96 if (br_multicast_rcv(&brmctx, &pmctx_null, vlan, skb, vid)) {
97 kfree_skb(skb);
98 goto out;
99 }
100
101 mdst = br_mdb_entry_skb_get(brmctx, skb, vid);
102 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
103 br_multicast_querier_exists(brmctx, eth_hdr(skb), mdst))
104 br_multicast_flood(mdst, skb, brmctx, false, true);
105 else
106 br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid);
107 } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
108 br_forward(dst->dst, skb, false, true);
109 } else {
110 br_flood(br, skb, BR_PKT_UNICAST, false, true, vid);
111 }
112 out:
113 rcu_read_unlock();
114 return NETDEV_TX_OK;
115 }
116
br_dev_init(struct net_device * dev)117 static int br_dev_init(struct net_device *dev)
118 {
119 struct net_bridge *br = netdev_priv(dev);
120 int err;
121
122 err = br_fdb_hash_init(br);
123 if (err)
124 return err;
125
126 err = br_mdb_hash_init(br);
127 if (err) {
128 br_fdb_hash_fini(br);
129 return err;
130 }
131
132 err = br_vlan_init(br);
133 if (err) {
134 br_mdb_hash_fini(br);
135 br_fdb_hash_fini(br);
136 return err;
137 }
138
139 err = br_multicast_init_stats(br);
140 if (err) {
141 br_vlan_flush(br);
142 br_mdb_hash_fini(br);
143 br_fdb_hash_fini(br);
144 return err;
145 }
146
147 netdev_lockdep_set_classes(dev);
148 return 0;
149 }
150
br_dev_uninit(struct net_device * dev)151 static void br_dev_uninit(struct net_device *dev)
152 {
153 struct net_bridge *br = netdev_priv(dev);
154
155 br_multicast_dev_del(br);
156 br_multicast_uninit_stats(br);
157 br_vlan_flush(br);
158 br_mdb_hash_fini(br);
159 br_fdb_hash_fini(br);
160 }
161
br_dev_open(struct net_device * dev)162 static int br_dev_open(struct net_device *dev)
163 {
164 struct net_bridge *br = netdev_priv(dev);
165
166 netdev_update_features(dev);
167 netif_start_queue(dev);
168 br_stp_enable_bridge(br);
169 br_multicast_open(br);
170
171 if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
172 br_multicast_join_snoopers(br);
173
174 return 0;
175 }
176
br_dev_set_multicast_list(struct net_device * dev)177 static void br_dev_set_multicast_list(struct net_device *dev)
178 {
179 }
180
br_dev_change_rx_flags(struct net_device * dev,int change)181 static void br_dev_change_rx_flags(struct net_device *dev, int change)
182 {
183 if (change & IFF_PROMISC)
184 br_manage_promisc(netdev_priv(dev));
185 }
186
br_dev_stop(struct net_device * dev)187 static int br_dev_stop(struct net_device *dev)
188 {
189 struct net_bridge *br = netdev_priv(dev);
190
191 br_stp_disable_bridge(br);
192 br_multicast_stop(br);
193
194 if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
195 br_multicast_leave_snoopers(br);
196
197 netif_stop_queue(dev);
198
199 return 0;
200 }
201
br_change_mtu(struct net_device * dev,int new_mtu)202 static int br_change_mtu(struct net_device *dev, int new_mtu)
203 {
204 struct net_bridge *br = netdev_priv(dev);
205
206 WRITE_ONCE(dev->mtu, new_mtu);
207
208 /* this flag will be cleared if the MTU was automatically adjusted */
209 br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
210 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
211 /* remember the MTU in the rtable for PMTU */
212 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
213 #endif
214
215 return 0;
216 }
217
218 /* Allow setting mac address to any valid ethernet address. */
br_set_mac_address(struct net_device * dev,void * p)219 static int br_set_mac_address(struct net_device *dev, void *p)
220 {
221 struct net_bridge *br = netdev_priv(dev);
222 struct sockaddr *addr = p;
223
224 if (!is_valid_ether_addr(addr->sa_data))
225 return -EADDRNOTAVAIL;
226
227 /* dev_set_mac_addr() can be called by a master device on bridge's
228 * NETDEV_UNREGISTER, but since it's being destroyed do nothing
229 */
230 if (dev->reg_state != NETREG_REGISTERED)
231 return -EBUSY;
232
233 spin_lock_bh(&br->lock);
234 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
235 /* Mac address will be changed in br_stp_change_bridge_id(). */
236 br_stp_change_bridge_id(br, addr->sa_data);
237 }
238 spin_unlock_bh(&br->lock);
239
240 return 0;
241 }
242
br_getinfo(struct net_device * dev,struct ethtool_drvinfo * info)243 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
244 {
245 strscpy(info->driver, "bridge", sizeof(info->driver));
246 strscpy(info->version, BR_VERSION, sizeof(info->version));
247 strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
248 strscpy(info->bus_info, "N/A", sizeof(info->bus_info));
249 }
250
br_get_link_ksettings(struct net_device * dev,struct ethtool_link_ksettings * cmd)251 static int br_get_link_ksettings(struct net_device *dev,
252 struct ethtool_link_ksettings *cmd)
253 {
254 struct net_bridge *br = netdev_priv(dev);
255 struct net_bridge_port *p;
256
257 cmd->base.duplex = DUPLEX_UNKNOWN;
258 cmd->base.port = PORT_OTHER;
259 cmd->base.speed = SPEED_UNKNOWN;
260
261 list_for_each_entry(p, &br->port_list, list) {
262 struct ethtool_link_ksettings ecmd;
263 struct net_device *pdev = p->dev;
264
265 if (!netif_running(pdev) || !netif_oper_up(pdev))
266 continue;
267
268 if (__ethtool_get_link_ksettings(pdev, &ecmd))
269 continue;
270
271 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
272 continue;
273
274 if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
275 cmd->base.speed < ecmd.base.speed)
276 cmd->base.speed = ecmd.base.speed;
277 }
278
279 return 0;
280 }
281
br_fix_features(struct net_device * dev,netdev_features_t features)282 static netdev_features_t br_fix_features(struct net_device *dev,
283 netdev_features_t features)
284 {
285 struct net_bridge *br = netdev_priv(dev);
286
287 return br_features_recompute(br, features);
288 }
289
290 #ifdef CONFIG_NET_POLL_CONTROLLER
br_poll_controller(struct net_device * br_dev)291 static void br_poll_controller(struct net_device *br_dev)
292 {
293 }
294
br_netpoll_cleanup(struct net_device * dev)295 static void br_netpoll_cleanup(struct net_device *dev)
296 {
297 struct net_bridge *br = netdev_priv(dev);
298 struct net_bridge_port *p;
299
300 list_for_each_entry(p, &br->port_list, list)
301 br_netpoll_disable(p);
302 }
303
__br_netpoll_enable(struct net_bridge_port * p)304 static int __br_netpoll_enable(struct net_bridge_port *p)
305 {
306 struct netpoll *np;
307 int err;
308
309 np = kzalloc(sizeof(*p->np), GFP_KERNEL);
310 if (!np)
311 return -ENOMEM;
312
313 err = __netpoll_setup(np, p->dev);
314 if (err) {
315 kfree(np);
316 return err;
317 }
318
319 p->np = np;
320 return err;
321 }
322
br_netpoll_enable(struct net_bridge_port * p)323 int br_netpoll_enable(struct net_bridge_port *p)
324 {
325 if (!p->br->dev->npinfo)
326 return 0;
327
328 return __br_netpoll_enable(p);
329 }
330
br_netpoll_setup(struct net_device * dev)331 static int br_netpoll_setup(struct net_device *dev)
332 {
333 struct net_bridge *br = netdev_priv(dev);
334 struct net_bridge_port *p;
335 int err = 0;
336
337 list_for_each_entry(p, &br->port_list, list) {
338 if (!p->dev)
339 continue;
340 err = __br_netpoll_enable(p);
341 if (err)
342 goto fail;
343 }
344
345 out:
346 return err;
347
348 fail:
349 br_netpoll_cleanup(dev);
350 goto out;
351 }
352
br_netpoll_disable(struct net_bridge_port * p)353 void br_netpoll_disable(struct net_bridge_port *p)
354 {
355 struct netpoll *np = p->np;
356
357 if (!np)
358 return;
359
360 p->np = NULL;
361
362 __netpoll_free(np);
363 }
364
365 #endif
366
br_add_slave(struct net_device * dev,struct net_device * slave_dev,struct netlink_ext_ack * extack)367 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
368 struct netlink_ext_ack *extack)
369
370 {
371 struct net_bridge *br = netdev_priv(dev);
372
373 return br_add_if(br, slave_dev, extack);
374 }
375
br_del_slave(struct net_device * dev,struct net_device * slave_dev)376 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
377 {
378 struct net_bridge *br = netdev_priv(dev);
379
380 return br_del_if(br, slave_dev);
381 }
382
br_fill_forward_path(struct net_device_path_ctx * ctx,struct net_device_path * path)383 static int br_fill_forward_path(struct net_device_path_ctx *ctx,
384 struct net_device_path *path)
385 {
386 struct net_bridge_fdb_entry *f;
387 struct net_bridge_port *dst;
388 struct net_bridge *br;
389
390 if (netif_is_bridge_port(ctx->dev))
391 return -1;
392
393 br = netdev_priv(ctx->dev);
394
395 br_vlan_fill_forward_path_pvid(br, ctx, path);
396
397 f = br_fdb_find_rcu(br, ctx->daddr, path->bridge.vlan_id);
398 if (!f)
399 return -1;
400
401 dst = READ_ONCE(f->dst);
402 if (!dst)
403 return -1;
404
405 if (br_vlan_fill_forward_path_mode(br, dst, path))
406 return -1;
407
408 path->type = DEV_PATH_BRIDGE;
409 path->dev = dst->br->dev;
410 ctx->dev = dst->dev;
411
412 switch (path->bridge.vlan_mode) {
413 case DEV_PATH_BR_VLAN_TAG:
414 if (ctx->num_vlans >= ARRAY_SIZE(ctx->vlan))
415 return -ENOSPC;
416 ctx->vlan[ctx->num_vlans].id = path->bridge.vlan_id;
417 ctx->vlan[ctx->num_vlans].proto = path->bridge.vlan_proto;
418 ctx->num_vlans++;
419 break;
420 case DEV_PATH_BR_VLAN_UNTAG_HW:
421 case DEV_PATH_BR_VLAN_UNTAG:
422 ctx->num_vlans--;
423 break;
424 case DEV_PATH_BR_VLAN_KEEP:
425 break;
426 }
427
428 return 0;
429 }
430
431 static const struct ethtool_ops br_ethtool_ops = {
432 .get_drvinfo = br_getinfo,
433 .get_link = ethtool_op_get_link,
434 .get_link_ksettings = br_get_link_ksettings,
435 };
436
437 static const struct net_device_ops br_netdev_ops = {
438 .ndo_open = br_dev_open,
439 .ndo_stop = br_dev_stop,
440 .ndo_init = br_dev_init,
441 .ndo_uninit = br_dev_uninit,
442 .ndo_start_xmit = br_dev_xmit,
443 .ndo_get_stats64 = dev_get_tstats64,
444 .ndo_set_mac_address = br_set_mac_address,
445 .ndo_set_rx_mode = br_dev_set_multicast_list,
446 .ndo_change_rx_flags = br_dev_change_rx_flags,
447 .ndo_change_mtu = br_change_mtu,
448 .ndo_siocdevprivate = br_dev_siocdevprivate,
449 #ifdef CONFIG_NET_POLL_CONTROLLER
450 .ndo_netpoll_setup = br_netpoll_setup,
451 .ndo_netpoll_cleanup = br_netpoll_cleanup,
452 .ndo_poll_controller = br_poll_controller,
453 #endif
454 .ndo_add_slave = br_add_slave,
455 .ndo_del_slave = br_del_slave,
456 .ndo_fix_features = br_fix_features,
457 .ndo_fdb_add = br_fdb_add,
458 .ndo_fdb_del = br_fdb_delete,
459 .ndo_fdb_del_bulk = br_fdb_delete_bulk,
460 .ndo_fdb_dump = br_fdb_dump,
461 .ndo_fdb_get = br_fdb_get,
462 .ndo_mdb_add = br_mdb_add,
463 .ndo_mdb_del = br_mdb_del,
464 .ndo_mdb_del_bulk = br_mdb_del_bulk,
465 .ndo_mdb_dump = br_mdb_dump,
466 .ndo_mdb_get = br_mdb_get,
467 .ndo_bridge_getlink = br_getlink,
468 .ndo_bridge_setlink = br_setlink,
469 .ndo_bridge_dellink = br_dellink,
470 .ndo_features_check = passthru_features_check,
471 .ndo_fill_forward_path = br_fill_forward_path,
472 };
473
474 static const struct device_type br_type = {
475 .name = "bridge",
476 };
477
br_dev_setup(struct net_device * dev)478 void br_dev_setup(struct net_device *dev)
479 {
480 struct net_bridge *br = netdev_priv(dev);
481
482 eth_hw_addr_random(dev);
483 ether_setup(dev);
484
485 dev->netdev_ops = &br_netdev_ops;
486 dev->needs_free_netdev = true;
487 dev->ethtool_ops = &br_ethtool_ops;
488 SET_NETDEV_DEVTYPE(dev, &br_type);
489 dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
490 dev->lltx = true;
491 dev->netns_local = true;
492
493 dev->features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
494 NETIF_F_HW_VLAN_STAG_TX;
495 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
496 NETIF_F_HW_VLAN_STAG_TX;
497 dev->vlan_features = COMMON_FEATURES;
498 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
499
500 br->dev = dev;
501 spin_lock_init(&br->lock);
502 INIT_LIST_HEAD(&br->port_list);
503 INIT_HLIST_HEAD(&br->fdb_list);
504 INIT_HLIST_HEAD(&br->frame_type_list);
505 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
506 INIT_HLIST_HEAD(&br->mrp_list);
507 #endif
508 #if IS_ENABLED(CONFIG_BRIDGE_CFM)
509 INIT_HLIST_HEAD(&br->mep_list);
510 #endif
511 spin_lock_init(&br->hash_lock);
512
513 br->bridge_id.prio[0] = 0x80;
514 br->bridge_id.prio[1] = 0x00;
515
516 ether_addr_copy(br->group_addr, eth_stp_addr);
517
518 br->stp_enabled = BR_NO_STP;
519 br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
520 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
521
522 br->designated_root = br->bridge_id;
523 br->bridge_max_age = br->max_age = 20 * HZ;
524 br->bridge_hello_time = br->hello_time = 2 * HZ;
525 br->bridge_forward_delay = br->forward_delay = 15 * HZ;
526 br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
527 dev->max_mtu = ETH_MAX_MTU;
528
529 br_netfilter_rtable_init(br);
530 br_stp_timer_init(br);
531 br_multicast_init(br);
532 INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
533 }
534