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
24const struct nf_br_ops __rcu *nf_br_ops __read_mostly;
25EXPORT_SYMBOL_GPL(nf_br_ops);
26
27/* net device transmit always called with BH disabled */
28netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
29{
30 struct net_bridge_mcast_port *pmctx_null = NULL;
31 struct net_bridge *br = netdev_priv(dev);
32 struct net_bridge_mcast *brmctx = &br->multicast_ctx;
33 struct net_bridge_fdb_entry *dst;
34 struct net_bridge_mdb_entry *mdst;
35 const struct nf_br_ops *nf_ops;
36 u8 state = BR_STATE_FORWARDING;
37 struct net_bridge_vlan *vlan;
38 const unsigned char *dest;
39 u16 vid = 0;
40
41 memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
42 br_tc_skb_miss_set(skb, miss: false);
43
44 rcu_read_lock();
45 nf_ops = rcu_dereference(nf_br_ops);
46 if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
47 rcu_read_unlock();
48 return NETDEV_TX_OK;
49 }
50
51 dev_sw_netstats_tx_add(dev, packets: 1, len: skb->len);
52
53 br_switchdev_frame_unmark(skb);
54 BR_INPUT_SKB_CB(skb)->brdev = dev;
55 BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
56
57 skb_reset_mac_header(skb);
58 skb_pull(skb, ETH_HLEN);
59
60 if (!br_allowed_ingress(br, vg: br_vlan_group_rcu(br), skb, vid: &vid,
61 state: &state, vlan: &vlan))
62 goto out;
63
64 if (IS_ENABLED(CONFIG_INET) &&
65 (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) ||
66 eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) &&
67 br_opt_get(br, opt: BROPT_NEIGH_SUPPRESS_ENABLED)) {
68 br_do_proxy_suppress_arp(skb, br, vid, NULL);
69 } else if (IS_ENABLED(CONFIG_IPV6) &&
70 skb->protocol == htons(ETH_P_IPV6) &&
71 br_opt_get(br, opt: BROPT_NEIGH_SUPPRESS_ENABLED) &&
72 pskb_may_pull(skb, len: sizeof(struct ipv6hdr) +
73 sizeof(struct nd_msg)) &&
74 ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
75 struct nd_msg *msg, _msg;
76
77 msg = br_is_nd_neigh_msg(skb, m: &_msg);
78 if (msg)
79 br_do_suppress_nd(skb, br, vid, NULL, msg);
80 }
81
82 dest = eth_hdr(skb)->h_dest;
83 if (is_broadcast_ether_addr(addr: dest)) {
84 br_flood(br, skb, pkt_type: BR_PKT_BROADCAST, local_rcv: false, local_orig: true, vid);
85 } else if (is_multicast_ether_addr(addr: dest)) {
86 if (unlikely(netpoll_tx_running(dev))) {
87 br_flood(br, skb, pkt_type: BR_PKT_MULTICAST, local_rcv: false, local_orig: true, vid);
88 goto out;
89 }
90 if (br_multicast_rcv(brmctx: &brmctx, pmctx: &pmctx_null, vlan, skb, vid)) {
91 kfree_skb(skb);
92 goto out;
93 }
94
95 mdst = br_mdb_entry_skb_get(brmctx, skb, vid);
96 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
97 br_multicast_querier_exists(brmctx, eth: eth_hdr(skb), mdb: mdst))
98 br_multicast_flood(mdst, skb, brmctx, local_rcv: false, local_orig: true);
99 else
100 br_flood(br, skb, pkt_type: BR_PKT_MULTICAST, local_rcv: false, local_orig: true, vid);
101 } else if ((dst = br_fdb_find_rcu(br, addr: dest, vid)) != NULL) {
102 br_forward(to: dst->dst, skb, local_rcv: false, local_orig: true);
103 } else {
104 br_flood(br, skb, pkt_type: BR_PKT_UNICAST, local_rcv: false, local_orig: true, vid);
105 }
106out:
107 rcu_read_unlock();
108 return NETDEV_TX_OK;
109}
110
111static int br_dev_init(struct net_device *dev)
112{
113 struct net_bridge *br = netdev_priv(dev);
114 int err;
115
116 err = br_fdb_hash_init(br);
117 if (err)
118 return err;
119
120 err = br_mdb_hash_init(br);
121 if (err) {
122 br_fdb_hash_fini(br);
123 return err;
124 }
125
126 err = br_vlan_init(br);
127 if (err) {
128 br_mdb_hash_fini(br);
129 br_fdb_hash_fini(br);
130 return err;
131 }
132
133 err = br_multicast_init_stats(br);
134 if (err) {
135 br_vlan_flush(br);
136 br_mdb_hash_fini(br);
137 br_fdb_hash_fini(br);
138 return err;
139 }
140
141 netdev_lockdep_set_classes(dev);
142 return 0;
143}
144
145static void br_dev_uninit(struct net_device *dev)
146{
147 struct net_bridge *br = netdev_priv(dev);
148
149 br_multicast_dev_del(br);
150 br_multicast_uninit_stats(br);
151 br_vlan_flush(br);
152 br_mdb_hash_fini(br);
153 br_fdb_hash_fini(br);
154}
155
156static int br_dev_open(struct net_device *dev)
157{
158 struct net_bridge *br = netdev_priv(dev);
159
160 netdev_update_features(dev);
161 netif_start_queue(dev);
162 br_stp_enable_bridge(br);
163 br_multicast_open(br);
164
165 if (br_opt_get(br, opt: BROPT_MULTICAST_ENABLED))
166 br_multicast_join_snoopers(br);
167
168 return 0;
169}
170
171static void br_dev_set_multicast_list(struct net_device *dev)
172{
173}
174
175static void br_dev_change_rx_flags(struct net_device *dev, int change)
176{
177 if (change & IFF_PROMISC)
178 br_manage_promisc(br: netdev_priv(dev));
179}
180
181static int br_dev_stop(struct net_device *dev)
182{
183 struct net_bridge *br = netdev_priv(dev);
184
185 br_stp_disable_bridge(br);
186 br_multicast_stop(br);
187
188 if (br_opt_get(br, opt: BROPT_MULTICAST_ENABLED))
189 br_multicast_leave_snoopers(br);
190
191 netif_stop_queue(dev);
192
193 return 0;
194}
195
196static int br_change_mtu(struct net_device *dev, int new_mtu)
197{
198 struct net_bridge *br = netdev_priv(dev);
199
200 dev->mtu = new_mtu;
201
202 /* this flag will be cleared if the MTU was automatically adjusted */
203 br_opt_toggle(br, opt: BROPT_MTU_SET_BY_USER, on: true);
204#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
205 /* remember the MTU in the rtable for PMTU */
206 dst_metric_set(dst: &br->fake_rtable.dst, RTAX_MTU, val: new_mtu);
207#endif
208
209 return 0;
210}
211
212/* Allow setting mac address to any valid ethernet address. */
213static int br_set_mac_address(struct net_device *dev, void *p)
214{
215 struct net_bridge *br = netdev_priv(dev);
216 struct sockaddr *addr = p;
217
218 if (!is_valid_ether_addr(addr: addr->sa_data))
219 return -EADDRNOTAVAIL;
220
221 /* dev_set_mac_addr() can be called by a master device on bridge's
222 * NETDEV_UNREGISTER, but since it's being destroyed do nothing
223 */
224 if (dev->reg_state != NETREG_REGISTERED)
225 return -EBUSY;
226
227 spin_lock_bh(lock: &br->lock);
228 if (!ether_addr_equal(addr1: dev->dev_addr, addr2: addr->sa_data)) {
229 /* Mac address will be changed in br_stp_change_bridge_id(). */
230 br_stp_change_bridge_id(br, a: addr->sa_data);
231 }
232 spin_unlock_bh(lock: &br->lock);
233
234 return 0;
235}
236
237static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
238{
239 strscpy(info->driver, "bridge", sizeof(info->driver));
240 strscpy(info->version, BR_VERSION, sizeof(info->version));
241 strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
242 strscpy(info->bus_info, "N/A", sizeof(info->bus_info));
243}
244
245static int br_get_link_ksettings(struct net_device *dev,
246 struct ethtool_link_ksettings *cmd)
247{
248 struct net_bridge *br = netdev_priv(dev);
249 struct net_bridge_port *p;
250
251 cmd->base.duplex = DUPLEX_UNKNOWN;
252 cmd->base.port = PORT_OTHER;
253 cmd->base.speed = SPEED_UNKNOWN;
254
255 list_for_each_entry(p, &br->port_list, list) {
256 struct ethtool_link_ksettings ecmd;
257 struct net_device *pdev = p->dev;
258
259 if (!netif_running(dev: pdev) || !netif_oper_up(dev: pdev))
260 continue;
261
262 if (__ethtool_get_link_ksettings(dev: pdev, link_ksettings: &ecmd))
263 continue;
264
265 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
266 continue;
267
268 if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
269 cmd->base.speed < ecmd.base.speed)
270 cmd->base.speed = ecmd.base.speed;
271 }
272
273 return 0;
274}
275
276static netdev_features_t br_fix_features(struct net_device *dev,
277 netdev_features_t features)
278{
279 struct net_bridge *br = netdev_priv(dev);
280
281 return br_features_recompute(br, features);
282}
283
284#ifdef CONFIG_NET_POLL_CONTROLLER
285static void br_poll_controller(struct net_device *br_dev)
286{
287}
288
289static void br_netpoll_cleanup(struct net_device *dev)
290{
291 struct net_bridge *br = netdev_priv(dev);
292 struct net_bridge_port *p;
293
294 list_for_each_entry(p, &br->port_list, list)
295 br_netpoll_disable(p);
296}
297
298static int __br_netpoll_enable(struct net_bridge_port *p)
299{
300 struct netpoll *np;
301 int err;
302
303 np = kzalloc(size: sizeof(*p->np), GFP_KERNEL);
304 if (!np)
305 return -ENOMEM;
306
307 err = __netpoll_setup(np, ndev: p->dev);
308 if (err) {
309 kfree(objp: np);
310 return err;
311 }
312
313 p->np = np;
314 return err;
315}
316
317int br_netpoll_enable(struct net_bridge_port *p)
318{
319 if (!p->br->dev->npinfo)
320 return 0;
321
322 return __br_netpoll_enable(p);
323}
324
325static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
326{
327 struct net_bridge *br = netdev_priv(dev);
328 struct net_bridge_port *p;
329 int err = 0;
330
331 list_for_each_entry(p, &br->port_list, list) {
332 if (!p->dev)
333 continue;
334 err = __br_netpoll_enable(p);
335 if (err)
336 goto fail;
337 }
338
339out:
340 return err;
341
342fail:
343 br_netpoll_cleanup(dev);
344 goto out;
345}
346
347void br_netpoll_disable(struct net_bridge_port *p)
348{
349 struct netpoll *np = p->np;
350
351 if (!np)
352 return;
353
354 p->np = NULL;
355
356 __netpoll_free(np);
357}
358
359#endif
360
361static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
362 struct netlink_ext_ack *extack)
363
364{
365 struct net_bridge *br = netdev_priv(dev);
366
367 return br_add_if(br, dev: slave_dev, extack);
368}
369
370static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
371{
372 struct net_bridge *br = netdev_priv(dev);
373
374 return br_del_if(br, dev: slave_dev);
375}
376
377static int br_fill_forward_path(struct net_device_path_ctx *ctx,
378 struct net_device_path *path)
379{
380 struct net_bridge_fdb_entry *f;
381 struct net_bridge_port *dst;
382 struct net_bridge *br;
383
384 if (netif_is_bridge_port(dev: ctx->dev))
385 return -1;
386
387 br = netdev_priv(dev: ctx->dev);
388
389 br_vlan_fill_forward_path_pvid(br, ctx, path);
390
391 f = br_fdb_find_rcu(br, addr: ctx->daddr, vid: path->bridge.vlan_id);
392 if (!f || !f->dst)
393 return -1;
394
395 dst = READ_ONCE(f->dst);
396 if (!dst)
397 return -1;
398
399 if (br_vlan_fill_forward_path_mode(br, dst, path))
400 return -1;
401
402 path->type = DEV_PATH_BRIDGE;
403 path->dev = dst->br->dev;
404 ctx->dev = dst->dev;
405
406 switch (path->bridge.vlan_mode) {
407 case DEV_PATH_BR_VLAN_TAG:
408 if (ctx->num_vlans >= ARRAY_SIZE(ctx->vlan))
409 return -ENOSPC;
410 ctx->vlan[ctx->num_vlans].id = path->bridge.vlan_id;
411 ctx->vlan[ctx->num_vlans].proto = path->bridge.vlan_proto;
412 ctx->num_vlans++;
413 break;
414 case DEV_PATH_BR_VLAN_UNTAG_HW:
415 case DEV_PATH_BR_VLAN_UNTAG:
416 ctx->num_vlans--;
417 break;
418 case DEV_PATH_BR_VLAN_KEEP:
419 break;
420 }
421
422 return 0;
423}
424
425static const struct ethtool_ops br_ethtool_ops = {
426 .get_drvinfo = br_getinfo,
427 .get_link = ethtool_op_get_link,
428 .get_link_ksettings = br_get_link_ksettings,
429};
430
431static const struct net_device_ops br_netdev_ops = {
432 .ndo_open = br_dev_open,
433 .ndo_stop = br_dev_stop,
434 .ndo_init = br_dev_init,
435 .ndo_uninit = br_dev_uninit,
436 .ndo_start_xmit = br_dev_xmit,
437 .ndo_get_stats64 = dev_get_tstats64,
438 .ndo_set_mac_address = br_set_mac_address,
439 .ndo_set_rx_mode = br_dev_set_multicast_list,
440 .ndo_change_rx_flags = br_dev_change_rx_flags,
441 .ndo_change_mtu = br_change_mtu,
442 .ndo_siocdevprivate = br_dev_siocdevprivate,
443#ifdef CONFIG_NET_POLL_CONTROLLER
444 .ndo_netpoll_setup = br_netpoll_setup,
445 .ndo_netpoll_cleanup = br_netpoll_cleanup,
446 .ndo_poll_controller = br_poll_controller,
447#endif
448 .ndo_add_slave = br_add_slave,
449 .ndo_del_slave = br_del_slave,
450 .ndo_fix_features = br_fix_features,
451 .ndo_fdb_add = br_fdb_add,
452 .ndo_fdb_del = br_fdb_delete,
453 .ndo_fdb_del_bulk = br_fdb_delete_bulk,
454 .ndo_fdb_dump = br_fdb_dump,
455 .ndo_fdb_get = br_fdb_get,
456 .ndo_mdb_add = br_mdb_add,
457 .ndo_mdb_del = br_mdb_del,
458 .ndo_mdb_del_bulk = br_mdb_del_bulk,
459 .ndo_mdb_dump = br_mdb_dump,
460 .ndo_mdb_get = br_mdb_get,
461 .ndo_bridge_getlink = br_getlink,
462 .ndo_bridge_setlink = br_setlink,
463 .ndo_bridge_dellink = br_dellink,
464 .ndo_features_check = passthru_features_check,
465 .ndo_fill_forward_path = br_fill_forward_path,
466};
467
468static const struct device_type br_type = {
469 .name = "bridge",
470};
471
472void br_dev_setup(struct net_device *dev)
473{
474 struct net_bridge *br = netdev_priv(dev);
475
476 eth_hw_addr_random(dev);
477 ether_setup(dev);
478
479 dev->netdev_ops = &br_netdev_ops;
480 dev->needs_free_netdev = true;
481 dev->ethtool_ops = &br_ethtool_ops;
482 SET_NETDEV_DEVTYPE(dev, &br_type);
483 dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
484
485 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
486 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
487 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
488 NETIF_F_HW_VLAN_STAG_TX;
489 dev->vlan_features = COMMON_FEATURES;
490 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
491
492 br->dev = dev;
493 spin_lock_init(&br->lock);
494 INIT_LIST_HEAD(list: &br->port_list);
495 INIT_HLIST_HEAD(&br->fdb_list);
496 INIT_HLIST_HEAD(&br->frame_type_list);
497#if IS_ENABLED(CONFIG_BRIDGE_MRP)
498 INIT_HLIST_HEAD(&br->mrp_list);
499#endif
500#if IS_ENABLED(CONFIG_BRIDGE_CFM)
501 INIT_HLIST_HEAD(&br->mep_list);
502#endif
503 spin_lock_init(&br->hash_lock);
504
505 br->bridge_id.prio[0] = 0x80;
506 br->bridge_id.prio[1] = 0x00;
507
508 ether_addr_copy(dst: br->group_addr, eth_stp_addr);
509
510 br->stp_enabled = BR_NO_STP;
511 br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
512 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
513
514 br->designated_root = br->bridge_id;
515 br->bridge_max_age = br->max_age = 20 * HZ;
516 br->bridge_hello_time = br->hello_time = 2 * HZ;
517 br->bridge_forward_delay = br->forward_delay = 15 * HZ;
518 br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
519 dev->max_mtu = ETH_MAX_MTU;
520
521 br_netfilter_rtable_init(br);
522 br_stp_timer_init(br);
523 br_multicast_init(br);
524 INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
525}
526

source code of linux/net/bridge/br_device.c