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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Userspace interface
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/etherdevice.h>
13#include <linux/netpoll.h>
14#include <linux/ethtool.h>
15#include <linux/if_arp.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/rtnetlink.h>
19#include <linux/if_ether.h>
20#include <linux/slab.h>
21#include <net/dsa.h>
22#include <net/sock.h>
23#include <linux/if_vlan.h>
24#include <net/switchdev.h>
25#include <net/net_namespace.h>
26
27#include "br_private.h"
28
29/*
30 * Determine initial path cost based on speed.
31 * using recommendations from 802.1d standard
32 *
33 * Since driver might sleep need to not be holding any locks.
34 */
35static int port_cost(struct net_device *dev)
36{
37 struct ethtool_link_ksettings ecmd;
38
39 if (!__ethtool_get_link_ksettings(dev, &ecmd)) {
40 switch (ecmd.base.speed) {
41 case SPEED_10000:
42 return 2;
43 case SPEED_5000:
44 return 3;
45 case SPEED_2500:
46 return 4;
47 case SPEED_1000:
48 return 5;
49 case SPEED_100:
50 return 19;
51 case SPEED_10:
52 return 100;
53 case SPEED_UNKNOWN:
54 return 100;
55 default:
56 if (ecmd.base.speed > SPEED_10000)
57 return 1;
58 }
59 }
60
61 /* Old silly heuristics based on name */
62 if (!strncmp(dev->name, "lec", 3))
63 return 7;
64
65 if (!strncmp(dev->name, "plip", 4))
66 return 2500;
67
68 return 100; /* assume old 10Mbps */
69}
70
71
72/* Check for port carrier transitions. */
73void br_port_carrier_check(struct net_bridge_port *p, bool *notified)
74{
75 struct net_device *dev = p->dev;
76 struct net_bridge *br = p->br;
77
78 if (!(p->flags & BR_ADMIN_COST) &&
79 netif_running(dev) && netif_oper_up(dev))
80 p->path_cost = port_cost(dev);
81
82 *notified = false;
83 if (!netif_running(br->dev))
84 return;
85
86 spin_lock_bh(&br->lock);
87 if (netif_running(dev) && netif_oper_up(dev)) {
88 if (p->state == BR_STATE_DISABLED) {
89 br_stp_enable_port(p);
90 *notified = true;
91 }
92 } else {
93 if (p->state != BR_STATE_DISABLED) {
94 br_stp_disable_port(p);
95 *notified = true;
96 }
97 }
98 spin_unlock_bh(&br->lock);
99}
100
101static void br_port_set_promisc(struct net_bridge_port *p)
102{
103 int err = 0;
104
105 if (br_promisc_port(p))
106 return;
107
108 err = dev_set_promiscuity(p->dev, 1);
109 if (err)
110 return;
111
112 br_fdb_unsync_static(p->br, p);
113 p->flags |= BR_PROMISC;
114}
115
116static void br_port_clear_promisc(struct net_bridge_port *p)
117{
118 int err;
119
120 /* Check if the port is already non-promisc or if it doesn't
121 * support UNICAST filtering. Without unicast filtering support
122 * we'll end up re-enabling promisc mode anyway, so just check for
123 * it here.
124 */
125 if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT))
126 return;
127
128 /* Since we'll be clearing the promisc mode, program the port
129 * first so that we don't have interruption in traffic.
130 */
131 err = br_fdb_sync_static(p->br, p);
132 if (err)
133 return;
134
135 dev_set_promiscuity(p->dev, -1);
136 p->flags &= ~BR_PROMISC;
137}
138
139/* When a port is added or removed or when certain port flags
140 * change, this function is called to automatically manage
141 * promiscuity setting of all the bridge ports. We are always called
142 * under RTNL so can skip using rcu primitives.
143 */
144void br_manage_promisc(struct net_bridge *br)
145{
146 struct net_bridge_port *p;
147 bool set_all = false;
148
149 /* If vlan filtering is disabled or bridge interface is placed
150 * into promiscuous mode, place all ports in promiscuous mode.
151 */
152 if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br->dev))
153 set_all = true;
154
155 list_for_each_entry(p, &br->port_list, list) {
156 if (set_all) {
157 br_port_set_promisc(p);
158 } else {
159 /* If the number of auto-ports is <= 1, then all other
160 * ports will have their output configuration
161 * statically specified through fdbs. Since ingress
162 * on the auto-port becomes forwarding/egress to other
163 * ports and egress configuration is statically known,
164 * we can say that ingress configuration of the
165 * auto-port is also statically known.
166 * This lets us disable promiscuous mode and write
167 * this config to hw.
168 */
169 if ((p->dev->priv_flags & IFF_UNICAST_FLT) &&
170 (br->auto_cnt == 0 ||
171 (br->auto_cnt == 1 && br_auto_port(p))))
172 br_port_clear_promisc(p);
173 else
174 br_port_set_promisc(p);
175 }
176 }
177}
178
179int nbp_backup_change(struct net_bridge_port *p,
180 struct net_device *backup_dev)
181{
182 struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port);
183 struct net_bridge_port *backup_p = NULL;
184
185 ASSERT_RTNL();
186
187 if (backup_dev) {
188 if (!netif_is_bridge_port(backup_dev))
189 return -ENOENT;
190
191 backup_p = br_port_get_rtnl(backup_dev);
192 if (backup_p->br != p->br)
193 return -EINVAL;
194 }
195
196 if (p == backup_p)
197 return -EINVAL;
198
199 if (old_backup == backup_p)
200 return 0;
201
202 /* if the backup link is already set, clear it */
203 if (old_backup)
204 old_backup->backup_redirected_cnt--;
205
206 if (backup_p)
207 backup_p->backup_redirected_cnt++;
208 rcu_assign_pointer(p->backup_port, backup_p);
209
210 return 0;
211}
212
213static void nbp_backup_clear(struct net_bridge_port *p)
214{
215 nbp_backup_change(p, NULL);
216 if (p->backup_redirected_cnt) {
217 struct net_bridge_port *cur_p;
218
219 list_for_each_entry(cur_p, &p->br->port_list, list) {
220 struct net_bridge_port *backup_p;
221
222 backup_p = rtnl_dereference(cur_p->backup_port);
223 if (backup_p == p)
224 nbp_backup_change(cur_p, NULL);
225 }
226 }
227
228 WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt);
229}
230
231static void nbp_update_port_count(struct net_bridge *br)
232{
233 struct net_bridge_port *p;
234 u32 cnt = 0;
235
236 list_for_each_entry(p, &br->port_list, list) {
237 if (br_auto_port(p))
238 cnt++;
239 }
240 if (br->auto_cnt != cnt) {
241 br->auto_cnt = cnt;
242 br_manage_promisc(br);
243 }
244}
245
246static void nbp_delete_promisc(struct net_bridge_port *p)
247{
248 /* If port is currently promiscuous, unset promiscuity.
249 * Otherwise, it is a static port so remove all addresses
250 * from it.
251 */
252 dev_set_allmulti(p->dev, -1);
253 if (br_promisc_port(p))
254 dev_set_promiscuity(p->dev, -1);
255 else
256 br_fdb_unsync_static(p->br, p);
257}
258
259static void release_nbp(struct kobject *kobj)
260{
261 struct net_bridge_port *p
262 = container_of(kobj, struct net_bridge_port, kobj);
263 kfree(p);
264}
265
266static void brport_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t *gid)
267{
268 struct net_bridge_port *p = kobj_to_brport(kobj);
269
270 net_ns_get_ownership(dev_net(p->dev), uid, gid);
271}
272
273static const struct kobj_type brport_ktype = {
274#ifdef CONFIG_SYSFS
275 .sysfs_ops = &brport_sysfs_ops,
276#endif
277 .release = release_nbp,
278 .get_ownership = brport_get_ownership,
279};
280
281static void destroy_nbp(struct net_bridge_port *p)
282{
283 struct net_device *dev = p->dev;
284
285 p->br = NULL;
286 p->dev = NULL;
287 netdev_put(dev, &p->dev_tracker);
288
289 kobject_put(&p->kobj);
290}
291
292static void destroy_nbp_rcu(struct rcu_head *head)
293{
294 struct net_bridge_port *p =
295 container_of(head, struct net_bridge_port, rcu);
296 destroy_nbp(p);
297}
298
299static unsigned get_max_headroom(struct net_bridge *br)
300{
301 unsigned max_headroom = 0;
302 struct net_bridge_port *p;
303
304 list_for_each_entry(p, &br->port_list, list) {
305 unsigned dev_headroom = netdev_get_fwd_headroom(p->dev);
306
307 if (dev_headroom > max_headroom)
308 max_headroom = dev_headroom;
309 }
310
311 return max_headroom;
312}
313
314static void update_headroom(struct net_bridge *br, int new_hr)
315{
316 struct net_bridge_port *p;
317
318 list_for_each_entry(p, &br->port_list, list)
319 netdev_set_rx_headroom(p->dev, new_hr);
320
321 br->dev->needed_headroom = new_hr;
322}
323
324/* Delete port(interface) from bridge is done in two steps.
325 * via RCU. First step, marks device as down. That deletes
326 * all the timers and stops new packets from flowing through.
327 *
328 * Final cleanup doesn't occur until after all CPU's finished
329 * processing packets.
330 *
331 * Protected from multiple admin operations by RTNL mutex
332 */
333static void del_nbp(struct net_bridge_port *p)
334{
335 struct net_bridge *br = p->br;
336 struct net_device *dev = p->dev;
337
338 sysfs_remove_link(br->ifobj, p->dev->name);
339
340 nbp_delete_promisc(p);
341
342 spin_lock_bh(&br->lock);
343 br_stp_disable_port(p);
344 spin_unlock_bh(&br->lock);
345
346 br_mrp_port_del(br, p);
347 br_cfm_port_del(br, p);
348
349 br_ifinfo_notify(RTM_DELLINK, NULL, p);
350
351 list_del_rcu(&p->list);
352 if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
353 update_headroom(br, get_max_headroom(br));
354 netdev_reset_rx_headroom(dev);
355
356 nbp_vlan_flush(p);
357 br_fdb_delete_by_port(br, p, 0, 1);
358 switchdev_deferred_process();
359 nbp_backup_clear(p);
360
361 nbp_update_port_count(br);
362
363 netdev_upper_dev_unlink(dev, br->dev);
364
365 dev->priv_flags &= ~IFF_BRIDGE_PORT;
366
367 netdev_rx_handler_unregister(dev);
368
369 br_multicast_del_port(p);
370
371 kobject_uevent(&p->kobj, KOBJ_REMOVE);
372 kobject_del(&p->kobj);
373
374 br_netpoll_disable(p);
375
376 call_rcu(&p->rcu, destroy_nbp_rcu);
377}
378
379/* Delete bridge device */
380void br_dev_delete(struct net_device *dev, struct list_head *head)
381{
382 struct net_bridge *br = netdev_priv(dev);
383 struct net_bridge_port *p, *n;
384
385 list_for_each_entry_safe(p, n, &br->port_list, list) {
386 del_nbp(p);
387 }
388
389 br_recalculate_neigh_suppress_enabled(br);
390
391 br_fdb_delete_by_port(br, NULL, 0, 1);
392
393 cancel_delayed_work_sync(&br->gc_work);
394
395 br_sysfs_delbr(br->dev);
396 unregister_netdevice_queue(br->dev, head);
397}
398
399/* find an available port number */
400static int find_portno(struct net_bridge *br)
401{
402 int index;
403 struct net_bridge_port *p;
404 unsigned long *inuse;
405
406 inuse = bitmap_zalloc(BR_MAX_PORTS, GFP_KERNEL);
407 if (!inuse)
408 return -ENOMEM;
409
410 __set_bit(0, inuse); /* zero is reserved */
411 list_for_each_entry(p, &br->port_list, list)
412 __set_bit(p->port_no, inuse);
413
414 index = find_first_zero_bit(inuse, BR_MAX_PORTS);
415 bitmap_free(inuse);
416
417 return (index >= BR_MAX_PORTS) ? -EXFULL : index;
418}
419
420/* called with RTNL but without bridge lock */
421static struct net_bridge_port *new_nbp(struct net_bridge *br,
422 struct net_device *dev)
423{
424 struct net_bridge_port *p;
425 int index, err;
426
427 index = find_portno(br);
428 if (index < 0)
429 return ERR_PTR(index);
430
431 p = kzalloc(sizeof(*p), GFP_KERNEL);
432 if (p == NULL)
433 return ERR_PTR(-ENOMEM);
434
435 p->br = br;
436 netdev_hold(dev, &p->dev_tracker, GFP_KERNEL);
437 p->dev = dev;
438 p->path_cost = port_cost(dev);
439 p->priority = 0x8000 >> BR_PORT_BITS;
440 p->port_no = index;
441 p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
442 br_init_port(p);
443 br_set_state(p, BR_STATE_DISABLED);
444 br_stp_port_timer_init(p);
445 err = br_multicast_add_port(p);
446 if (err) {
447 netdev_put(dev, &p->dev_tracker);
448 kfree(p);
449 p = ERR_PTR(err);
450 }
451
452 return p;
453}
454
455int br_add_bridge(struct net *net, const char *name)
456{
457 struct net_device *dev;
458 int res;
459
460 dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
461 br_dev_setup);
462
463 if (!dev)
464 return -ENOMEM;
465
466 dev_net_set(dev, net);
467 dev->rtnl_link_ops = &br_link_ops;
468
469 res = register_netdevice(dev);
470 if (res)
471 free_netdev(dev);
472 return res;
473}
474
475int br_del_bridge(struct net *net, const char *name)
476{
477 struct net_device *dev;
478 int ret = 0;
479
480 dev = __dev_get_by_name(net, name);
481 if (dev == NULL)
482 ret = -ENXIO; /* Could not find device */
483
484 else if (!netif_is_bridge_master(dev)) {
485 /* Attempt to delete non bridge device! */
486 ret = -EPERM;
487 }
488
489 else if (dev->flags & IFF_UP) {
490 /* Not shutdown yet. */
491 ret = -EBUSY;
492 }
493
494 else
495 br_dev_delete(dev, NULL);
496
497 return ret;
498}
499
500/* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
501static int br_mtu_min(const struct net_bridge *br)
502{
503 const struct net_bridge_port *p;
504 int ret_mtu = 0;
505
506 list_for_each_entry(p, &br->port_list, list)
507 if (!ret_mtu || ret_mtu > p->dev->mtu)
508 ret_mtu = p->dev->mtu;
509
510 return ret_mtu ? ret_mtu : ETH_DATA_LEN;
511}
512
513void br_mtu_auto_adjust(struct net_bridge *br)
514{
515 ASSERT_RTNL();
516
517 /* if the bridge MTU was manually configured don't mess with it */
518 if (br_opt_get(br, BROPT_MTU_SET_BY_USER))
519 return;
520
521 /* change to the minimum MTU and clear the flag which was set by
522 * the bridge ndo_change_mtu callback
523 */
524 dev_set_mtu(br->dev, br_mtu_min(br));
525 br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false);
526}
527
528static void br_set_gso_limits(struct net_bridge *br)
529{
530 unsigned int tso_max_size = TSO_MAX_SIZE;
531 const struct net_bridge_port *p;
532 u16 tso_max_segs = TSO_MAX_SEGS;
533
534 list_for_each_entry(p, &br->port_list, list) {
535 tso_max_size = min(tso_max_size, p->dev->tso_max_size);
536 tso_max_segs = min(tso_max_segs, p->dev->tso_max_segs);
537 }
538 netif_set_tso_max_size(br->dev, tso_max_size);
539 netif_set_tso_max_segs(br->dev, tso_max_segs);
540}
541
542/*
543 * Recomputes features using slave's features
544 */
545netdev_features_t br_features_recompute(struct net_bridge *br,
546 netdev_features_t features)
547{
548 struct net_bridge_port *p;
549 netdev_features_t mask;
550
551 if (list_empty(&br->port_list))
552 return features;
553
554 mask = features;
555 features &= ~NETIF_F_ONE_FOR_ALL;
556
557 list_for_each_entry(p, &br->port_list, list) {
558 features = netdev_increment_features(features,
559 p->dev->features, mask);
560 }
561 features = netdev_add_tso_features(features, mask);
562
563 return features;
564}
565
566/* called with RTNL */
567int br_add_if(struct net_bridge *br, struct net_device *dev,
568 struct netlink_ext_ack *extack)
569{
570 struct net_bridge_port *p;
571 int err = 0;
572 unsigned br_hr, dev_hr;
573 bool changed_addr, fdb_synced = false;
574
575 /* Don't allow bridging non-ethernet like devices. */
576 if ((dev->flags & IFF_LOOPBACK) ||
577 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
578 !is_valid_ether_addr(dev->dev_addr))
579 return -EINVAL;
580
581 /* No bridging of bridges */
582 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
583 NL_SET_ERR_MSG(extack,
584 "Can not enslave a bridge to a bridge");
585 return -ELOOP;
586 }
587
588 /* Device has master upper dev */
589 if (netdev_master_upper_dev_get(dev))
590 return -EBUSY;
591
592 /* No bridging devices that dislike that (e.g. wireless) */
593 if (dev->priv_flags & IFF_DONT_BRIDGE) {
594 NL_SET_ERR_MSG(extack,
595 "Device does not allow enslaving to a bridge");
596 return -EOPNOTSUPP;
597 }
598
599 p = new_nbp(br, dev);
600 if (IS_ERR(p))
601 return PTR_ERR(p);
602
603 call_netdevice_notifiers(NETDEV_JOIN, dev);
604
605 err = dev_set_allmulti(dev, 1);
606 if (err) {
607 br_multicast_del_port(p);
608 netdev_put(dev, &p->dev_tracker);
609 kfree(p); /* kobject not yet init'd, manually free */
610 goto err1;
611 }
612
613 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
614 SYSFS_BRIDGE_PORT_ATTR);
615 if (err)
616 goto err2;
617
618 err = br_sysfs_addif(p);
619 if (err)
620 goto err2;
621
622 err = br_netpoll_enable(p);
623 if (err)
624 goto err3;
625
626 err = netdev_rx_handler_register(dev, br_get_rx_handler(dev), p);
627 if (err)
628 goto err4;
629
630 dev->priv_flags |= IFF_BRIDGE_PORT;
631
632 err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
633 if (err)
634 goto err5;
635
636 dev_disable_lro(dev);
637
638 list_add_rcu(&p->list, &br->port_list);
639
640 nbp_update_port_count(br);
641 if (!br_promisc_port(p) && (p->dev->priv_flags & IFF_UNICAST_FLT)) {
642 /* When updating the port count we also update all ports'
643 * promiscuous mode.
644 * A port leaving promiscuous mode normally gets the bridge's
645 * fdb synced to the unicast filter (if supported), however,
646 * `br_port_clear_promisc` does not distinguish between
647 * non-promiscuous ports and *new* ports, so we need to
648 * sync explicitly here.
649 */
650 fdb_synced = br_fdb_sync_static(br, p) == 0;
651 if (!fdb_synced)
652 netdev_err(dev, "failed to sync bridge static fdb addresses to this port\n");
653 }
654
655 netdev_update_features(br->dev);
656
657 br_hr = br->dev->needed_headroom;
658 dev_hr = netdev_get_fwd_headroom(dev);
659 if (br_hr < dev_hr)
660 update_headroom(br, dev_hr);
661 else
662 netdev_set_rx_headroom(dev, br_hr);
663
664 if (br_fdb_add_local(br, p, dev->dev_addr, 0))
665 netdev_err(dev, "failed insert local address bridge forwarding table\n");
666
667 if (br->dev->addr_assign_type != NET_ADDR_SET) {
668 /* Ask for permission to use this MAC address now, even if we
669 * don't end up choosing it below.
670 */
671 err = dev_pre_changeaddr_notify(br->dev, dev->dev_addr, extack);
672 if (err)
673 goto err6;
674 }
675
676 err = nbp_vlan_init(p, extack);
677 if (err) {
678 netdev_err(dev, "failed to initialize vlan filtering on this port\n");
679 goto err6;
680 }
681
682 spin_lock_bh(&br->lock);
683 changed_addr = br_stp_recalculate_bridge_id(br);
684
685 if (netif_running(dev) && netif_oper_up(dev) &&
686 (br->dev->flags & IFF_UP))
687 br_stp_enable_port(p);
688 spin_unlock_bh(&br->lock);
689
690 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
691
692 if (changed_addr)
693 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
694
695 br_mtu_auto_adjust(br);
696 br_set_gso_limits(br);
697
698 kobject_uevent(&p->kobj, KOBJ_ADD);
699
700 return 0;
701
702err6:
703 if (fdb_synced)
704 br_fdb_unsync_static(br, p);
705 list_del_rcu(&p->list);
706 br_fdb_delete_by_port(br, p, 0, 1);
707 nbp_update_port_count(br);
708 netdev_upper_dev_unlink(dev, br->dev);
709err5:
710 dev->priv_flags &= ~IFF_BRIDGE_PORT;
711 netdev_rx_handler_unregister(dev);
712err4:
713 br_netpoll_disable(p);
714err3:
715 sysfs_remove_link(br->ifobj, p->dev->name);
716err2:
717 br_multicast_del_port(p);
718 netdev_put(dev, &p->dev_tracker);
719 kobject_put(&p->kobj);
720 dev_set_allmulti(dev, -1);
721err1:
722 return err;
723}
724
725/* called with RTNL */
726int br_del_if(struct net_bridge *br, struct net_device *dev)
727{
728 struct net_bridge_port *p;
729 bool changed_addr;
730
731 p = br_port_get_rtnl(dev);
732 if (!p || p->br != br)
733 return -EINVAL;
734
735 /* Since more than one interface can be attached to a bridge,
736 * there still maybe an alternate path for netconsole to use;
737 * therefore there is no reason for a NETDEV_RELEASE event.
738 */
739 del_nbp(p);
740
741 br_mtu_auto_adjust(br);
742 br_set_gso_limits(br);
743
744 spin_lock_bh(&br->lock);
745 changed_addr = br_stp_recalculate_bridge_id(br);
746 spin_unlock_bh(&br->lock);
747
748 if (changed_addr)
749 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
750
751 netdev_update_features(br->dev);
752
753 return 0;
754}
755
756void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
757{
758 struct net_bridge *br = p->br;
759
760 if (mask & BR_AUTO_MASK)
761 nbp_update_port_count(br);
762
763 if (mask & (BR_NEIGH_SUPPRESS | BR_NEIGH_VLAN_SUPPRESS))
764 br_recalculate_neigh_suppress_enabled(br);
765}
766
767bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
768{
769 struct net_bridge_port *p;
770
771 p = br_port_get_rtnl_rcu(dev);
772 if (!p)
773 return false;
774
775 return p->flags & flag;
776}
777EXPORT_SYMBOL_GPL(br_port_flag_is_set);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Userspace interface
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/etherdevice.h>
13#include <linux/netpoll.h>
14#include <linux/ethtool.h>
15#include <linux/if_arp.h>
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/rtnetlink.h>
19#include <linux/if_ether.h>
20#include <linux/slab.h>
21#include <net/dsa.h>
22#include <net/sock.h>
23#include <linux/if_vlan.h>
24#include <net/switchdev.h>
25#include <net/net_namespace.h>
26
27#include "br_private.h"
28
29/*
30 * Determine initial path cost based on speed.
31 * using recommendations from 802.1d standard
32 *
33 * Since driver might sleep need to not be holding any locks.
34 */
35static int port_cost(struct net_device *dev)
36{
37 struct ethtool_link_ksettings ecmd;
38
39 if (!__ethtool_get_link_ksettings(dev, &ecmd)) {
40 switch (ecmd.base.speed) {
41 case SPEED_10000:
42 return 2;
43 case SPEED_1000:
44 return 4;
45 case SPEED_100:
46 return 19;
47 case SPEED_10:
48 return 100;
49 }
50 }
51
52 /* Old silly heuristics based on name */
53 if (!strncmp(dev->name, "lec", 3))
54 return 7;
55
56 if (!strncmp(dev->name, "plip", 4))
57 return 2500;
58
59 return 100; /* assume old 10Mbps */
60}
61
62
63/* Check for port carrier transitions. */
64void br_port_carrier_check(struct net_bridge_port *p, bool *notified)
65{
66 struct net_device *dev = p->dev;
67 struct net_bridge *br = p->br;
68
69 if (!(p->flags & BR_ADMIN_COST) &&
70 netif_running(dev) && netif_oper_up(dev))
71 p->path_cost = port_cost(dev);
72
73 *notified = false;
74 if (!netif_running(br->dev))
75 return;
76
77 spin_lock_bh(&br->lock);
78 if (netif_running(dev) && netif_oper_up(dev)) {
79 if (p->state == BR_STATE_DISABLED) {
80 br_stp_enable_port(p);
81 *notified = true;
82 }
83 } else {
84 if (p->state != BR_STATE_DISABLED) {
85 br_stp_disable_port(p);
86 *notified = true;
87 }
88 }
89 spin_unlock_bh(&br->lock);
90}
91
92static void br_port_set_promisc(struct net_bridge_port *p)
93{
94 int err = 0;
95
96 if (br_promisc_port(p))
97 return;
98
99 err = dev_set_promiscuity(p->dev, 1);
100 if (err)
101 return;
102
103 br_fdb_unsync_static(p->br, p);
104 p->flags |= BR_PROMISC;
105}
106
107static void br_port_clear_promisc(struct net_bridge_port *p)
108{
109 int err;
110
111 /* Check if the port is already non-promisc or if it doesn't
112 * support UNICAST filtering. Without unicast filtering support
113 * we'll end up re-enabling promisc mode anyway, so just check for
114 * it here.
115 */
116 if (!br_promisc_port(p) || !(p->dev->priv_flags & IFF_UNICAST_FLT))
117 return;
118
119 /* Since we'll be clearing the promisc mode, program the port
120 * first so that we don't have interruption in traffic.
121 */
122 err = br_fdb_sync_static(p->br, p);
123 if (err)
124 return;
125
126 dev_set_promiscuity(p->dev, -1);
127 p->flags &= ~BR_PROMISC;
128}
129
130/* When a port is added or removed or when certain port flags
131 * change, this function is called to automatically manage
132 * promiscuity setting of all the bridge ports. We are always called
133 * under RTNL so can skip using rcu primitives.
134 */
135void br_manage_promisc(struct net_bridge *br)
136{
137 struct net_bridge_port *p;
138 bool set_all = false;
139
140 /* If vlan filtering is disabled or bridge interface is placed
141 * into promiscuous mode, place all ports in promiscuous mode.
142 */
143 if ((br->dev->flags & IFF_PROMISC) || !br_vlan_enabled(br->dev))
144 set_all = true;
145
146 list_for_each_entry(p, &br->port_list, list) {
147 if (set_all) {
148 br_port_set_promisc(p);
149 } else {
150 /* If the number of auto-ports is <= 1, then all other
151 * ports will have their output configuration
152 * statically specified through fdbs. Since ingress
153 * on the auto-port becomes forwarding/egress to other
154 * ports and egress configuration is statically known,
155 * we can say that ingress configuration of the
156 * auto-port is also statically known.
157 * This lets us disable promiscuous mode and write
158 * this config to hw.
159 */
160 if (br->auto_cnt == 0 ||
161 (br->auto_cnt == 1 && br_auto_port(p)))
162 br_port_clear_promisc(p);
163 else
164 br_port_set_promisc(p);
165 }
166 }
167}
168
169int nbp_backup_change(struct net_bridge_port *p,
170 struct net_device *backup_dev)
171{
172 struct net_bridge_port *old_backup = rtnl_dereference(p->backup_port);
173 struct net_bridge_port *backup_p = NULL;
174
175 ASSERT_RTNL();
176
177 if (backup_dev) {
178 if (!netif_is_bridge_port(backup_dev))
179 return -ENOENT;
180
181 backup_p = br_port_get_rtnl(backup_dev);
182 if (backup_p->br != p->br)
183 return -EINVAL;
184 }
185
186 if (p == backup_p)
187 return -EINVAL;
188
189 if (old_backup == backup_p)
190 return 0;
191
192 /* if the backup link is already set, clear it */
193 if (old_backup)
194 old_backup->backup_redirected_cnt--;
195
196 if (backup_p)
197 backup_p->backup_redirected_cnt++;
198 rcu_assign_pointer(p->backup_port, backup_p);
199
200 return 0;
201}
202
203static void nbp_backup_clear(struct net_bridge_port *p)
204{
205 nbp_backup_change(p, NULL);
206 if (p->backup_redirected_cnt) {
207 struct net_bridge_port *cur_p;
208
209 list_for_each_entry(cur_p, &p->br->port_list, list) {
210 struct net_bridge_port *backup_p;
211
212 backup_p = rtnl_dereference(cur_p->backup_port);
213 if (backup_p == p)
214 nbp_backup_change(cur_p, NULL);
215 }
216 }
217
218 WARN_ON(rcu_access_pointer(p->backup_port) || p->backup_redirected_cnt);
219}
220
221static void nbp_update_port_count(struct net_bridge *br)
222{
223 struct net_bridge_port *p;
224 u32 cnt = 0;
225
226 list_for_each_entry(p, &br->port_list, list) {
227 if (br_auto_port(p))
228 cnt++;
229 }
230 if (br->auto_cnt != cnt) {
231 br->auto_cnt = cnt;
232 br_manage_promisc(br);
233 }
234}
235
236static void nbp_delete_promisc(struct net_bridge_port *p)
237{
238 /* If port is currently promiscuous, unset promiscuity.
239 * Otherwise, it is a static port so remove all addresses
240 * from it.
241 */
242 dev_set_allmulti(p->dev, -1);
243 if (br_promisc_port(p))
244 dev_set_promiscuity(p->dev, -1);
245 else
246 br_fdb_unsync_static(p->br, p);
247}
248
249static void release_nbp(struct kobject *kobj)
250{
251 struct net_bridge_port *p
252 = container_of(kobj, struct net_bridge_port, kobj);
253 kfree(p);
254}
255
256static void brport_get_ownership(struct kobject *kobj, kuid_t *uid, kgid_t *gid)
257{
258 struct net_bridge_port *p = kobj_to_brport(kobj);
259
260 net_ns_get_ownership(dev_net(p->dev), uid, gid);
261}
262
263static struct kobj_type brport_ktype = {
264#ifdef CONFIG_SYSFS
265 .sysfs_ops = &brport_sysfs_ops,
266#endif
267 .release = release_nbp,
268 .get_ownership = brport_get_ownership,
269};
270
271static void destroy_nbp(struct net_bridge_port *p)
272{
273 struct net_device *dev = p->dev;
274
275 p->br = NULL;
276 p->dev = NULL;
277 dev_put(dev);
278
279 kobject_put(&p->kobj);
280}
281
282static void destroy_nbp_rcu(struct rcu_head *head)
283{
284 struct net_bridge_port *p =
285 container_of(head, struct net_bridge_port, rcu);
286 destroy_nbp(p);
287}
288
289static unsigned get_max_headroom(struct net_bridge *br)
290{
291 unsigned max_headroom = 0;
292 struct net_bridge_port *p;
293
294 list_for_each_entry(p, &br->port_list, list) {
295 unsigned dev_headroom = netdev_get_fwd_headroom(p->dev);
296
297 if (dev_headroom > max_headroom)
298 max_headroom = dev_headroom;
299 }
300
301 return max_headroom;
302}
303
304static void update_headroom(struct net_bridge *br, int new_hr)
305{
306 struct net_bridge_port *p;
307
308 list_for_each_entry(p, &br->port_list, list)
309 netdev_set_rx_headroom(p->dev, new_hr);
310
311 br->dev->needed_headroom = new_hr;
312}
313
314/* Delete port(interface) from bridge is done in two steps.
315 * via RCU. First step, marks device as down. That deletes
316 * all the timers and stops new packets from flowing through.
317 *
318 * Final cleanup doesn't occur until after all CPU's finished
319 * processing packets.
320 *
321 * Protected from multiple admin operations by RTNL mutex
322 */
323static void del_nbp(struct net_bridge_port *p)
324{
325 struct net_bridge *br = p->br;
326 struct net_device *dev = p->dev;
327
328 sysfs_remove_link(br->ifobj, p->dev->name);
329
330 nbp_delete_promisc(p);
331
332 spin_lock_bh(&br->lock);
333 br_stp_disable_port(p);
334 spin_unlock_bh(&br->lock);
335
336 br_mrp_port_del(br, p);
337
338 br_ifinfo_notify(RTM_DELLINK, NULL, p);
339
340 list_del_rcu(&p->list);
341 if (netdev_get_fwd_headroom(dev) == br->dev->needed_headroom)
342 update_headroom(br, get_max_headroom(br));
343 netdev_reset_rx_headroom(dev);
344
345 nbp_vlan_flush(p);
346 br_fdb_delete_by_port(br, p, 0, 1);
347 switchdev_deferred_process();
348 nbp_backup_clear(p);
349
350 nbp_update_port_count(br);
351
352 netdev_upper_dev_unlink(dev, br->dev);
353
354 dev->priv_flags &= ~IFF_BRIDGE_PORT;
355
356 netdev_rx_handler_unregister(dev);
357
358 br_multicast_del_port(p);
359
360 kobject_uevent(&p->kobj, KOBJ_REMOVE);
361 kobject_del(&p->kobj);
362
363 br_netpoll_disable(p);
364
365 call_rcu(&p->rcu, destroy_nbp_rcu);
366}
367
368/* Delete bridge device */
369void br_dev_delete(struct net_device *dev, struct list_head *head)
370{
371 struct net_bridge *br = netdev_priv(dev);
372 struct net_bridge_port *p, *n;
373
374 list_for_each_entry_safe(p, n, &br->port_list, list) {
375 del_nbp(p);
376 }
377
378 br_recalculate_neigh_suppress_enabled(br);
379
380 br_fdb_delete_by_port(br, NULL, 0, 1);
381
382 cancel_delayed_work_sync(&br->gc_work);
383
384 br_sysfs_delbr(br->dev);
385 unregister_netdevice_queue(br->dev, head);
386}
387
388/* find an available port number */
389static int find_portno(struct net_bridge *br)
390{
391 int index;
392 struct net_bridge_port *p;
393 unsigned long *inuse;
394
395 inuse = bitmap_zalloc(BR_MAX_PORTS, GFP_KERNEL);
396 if (!inuse)
397 return -ENOMEM;
398
399 set_bit(0, inuse); /* zero is reserved */
400 list_for_each_entry(p, &br->port_list, list) {
401 set_bit(p->port_no, inuse);
402 }
403 index = find_first_zero_bit(inuse, BR_MAX_PORTS);
404 bitmap_free(inuse);
405
406 return (index >= BR_MAX_PORTS) ? -EXFULL : index;
407}
408
409/* called with RTNL but without bridge lock */
410static struct net_bridge_port *new_nbp(struct net_bridge *br,
411 struct net_device *dev)
412{
413 struct net_bridge_port *p;
414 int index, err;
415
416 index = find_portno(br);
417 if (index < 0)
418 return ERR_PTR(index);
419
420 p = kzalloc(sizeof(*p), GFP_KERNEL);
421 if (p == NULL)
422 return ERR_PTR(-ENOMEM);
423
424 p->br = br;
425 dev_hold(dev);
426 p->dev = dev;
427 p->path_cost = port_cost(dev);
428 p->priority = 0x8000 >> BR_PORT_BITS;
429 p->port_no = index;
430 p->flags = BR_LEARNING | BR_FLOOD | BR_MCAST_FLOOD | BR_BCAST_FLOOD;
431 br_init_port(p);
432 br_set_state(p, BR_STATE_DISABLED);
433 br_stp_port_timer_init(p);
434 err = br_multicast_add_port(p);
435 if (err) {
436 dev_put(dev);
437 kfree(p);
438 p = ERR_PTR(err);
439 }
440
441 return p;
442}
443
444int br_add_bridge(struct net *net, const char *name)
445{
446 struct net_device *dev;
447 int res;
448
449 dev = alloc_netdev(sizeof(struct net_bridge), name, NET_NAME_UNKNOWN,
450 br_dev_setup);
451
452 if (!dev)
453 return -ENOMEM;
454
455 dev_net_set(dev, net);
456 dev->rtnl_link_ops = &br_link_ops;
457
458 res = register_netdev(dev);
459 if (res)
460 free_netdev(dev);
461 return res;
462}
463
464int br_del_bridge(struct net *net, const char *name)
465{
466 struct net_device *dev;
467 int ret = 0;
468
469 rtnl_lock();
470 dev = __dev_get_by_name(net, name);
471 if (dev == NULL)
472 ret = -ENXIO; /* Could not find device */
473
474 else if (!(dev->priv_flags & IFF_EBRIDGE)) {
475 /* Attempt to delete non bridge device! */
476 ret = -EPERM;
477 }
478
479 else if (dev->flags & IFF_UP) {
480 /* Not shutdown yet. */
481 ret = -EBUSY;
482 }
483
484 else
485 br_dev_delete(dev, NULL);
486
487 rtnl_unlock();
488 return ret;
489}
490
491/* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
492static int br_mtu_min(const struct net_bridge *br)
493{
494 const struct net_bridge_port *p;
495 int ret_mtu = 0;
496
497 list_for_each_entry(p, &br->port_list, list)
498 if (!ret_mtu || ret_mtu > p->dev->mtu)
499 ret_mtu = p->dev->mtu;
500
501 return ret_mtu ? ret_mtu : ETH_DATA_LEN;
502}
503
504void br_mtu_auto_adjust(struct net_bridge *br)
505{
506 ASSERT_RTNL();
507
508 /* if the bridge MTU was manually configured don't mess with it */
509 if (br_opt_get(br, BROPT_MTU_SET_BY_USER))
510 return;
511
512 /* change to the minimum MTU and clear the flag which was set by
513 * the bridge ndo_change_mtu callback
514 */
515 dev_set_mtu(br->dev, br_mtu_min(br));
516 br_opt_toggle(br, BROPT_MTU_SET_BY_USER, false);
517}
518
519static void br_set_gso_limits(struct net_bridge *br)
520{
521 unsigned int gso_max_size = GSO_MAX_SIZE;
522 u16 gso_max_segs = GSO_MAX_SEGS;
523 const struct net_bridge_port *p;
524
525 list_for_each_entry(p, &br->port_list, list) {
526 gso_max_size = min(gso_max_size, p->dev->gso_max_size);
527 gso_max_segs = min(gso_max_segs, p->dev->gso_max_segs);
528 }
529 br->dev->gso_max_size = gso_max_size;
530 br->dev->gso_max_segs = gso_max_segs;
531}
532
533/*
534 * Recomputes features using slave's features
535 */
536netdev_features_t br_features_recompute(struct net_bridge *br,
537 netdev_features_t features)
538{
539 struct net_bridge_port *p;
540 netdev_features_t mask;
541
542 if (list_empty(&br->port_list))
543 return features;
544
545 mask = features;
546 features &= ~NETIF_F_ONE_FOR_ALL;
547
548 list_for_each_entry(p, &br->port_list, list) {
549 features = netdev_increment_features(features,
550 p->dev->features, mask);
551 }
552 features = netdev_add_tso_features(features, mask);
553
554 return features;
555}
556
557/* called with RTNL */
558int br_add_if(struct net_bridge *br, struct net_device *dev,
559 struct netlink_ext_ack *extack)
560{
561 struct net_bridge_port *p;
562 int err = 0;
563 unsigned br_hr, dev_hr;
564 bool changed_addr;
565
566 /* Don't allow bridging non-ethernet like devices. */
567 if ((dev->flags & IFF_LOOPBACK) ||
568 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN ||
569 !is_valid_ether_addr(dev->dev_addr))
570 return -EINVAL;
571
572 /* Also don't allow bridging of net devices that are DSA masters, since
573 * the bridge layer rx_handler prevents the DSA fake ethertype handler
574 * to be invoked, so we don't get the chance to strip off and parse the
575 * DSA switch tag protocol header (the bridge layer just returns
576 * RX_HANDLER_CONSUMED, stopping RX processing for these frames).
577 * The only case where that would not be an issue is when bridging can
578 * already be offloaded, such as when the DSA master is itself a DSA
579 * or plain switchdev port, and is bridged only with other ports from
580 * the same hardware device.
581 */
582 if (netdev_uses_dsa(dev)) {
583 list_for_each_entry(p, &br->port_list, list) {
584 if (!netdev_port_same_parent_id(dev, p->dev)) {
585 NL_SET_ERR_MSG(extack,
586 "Cannot do software bridging with a DSA master");
587 return -EINVAL;
588 }
589 }
590 }
591
592 /* No bridging of bridges */
593 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) {
594 NL_SET_ERR_MSG(extack,
595 "Can not enslave a bridge to a bridge");
596 return -ELOOP;
597 }
598
599 /* Device has master upper dev */
600 if (netdev_master_upper_dev_get(dev))
601 return -EBUSY;
602
603 /* No bridging devices that dislike that (e.g. wireless) */
604 if (dev->priv_flags & IFF_DONT_BRIDGE) {
605 NL_SET_ERR_MSG(extack,
606 "Device does not allow enslaving to a bridge");
607 return -EOPNOTSUPP;
608 }
609
610 p = new_nbp(br, dev);
611 if (IS_ERR(p))
612 return PTR_ERR(p);
613
614 call_netdevice_notifiers(NETDEV_JOIN, dev);
615
616 err = dev_set_allmulti(dev, 1);
617 if (err) {
618 kfree(p); /* kobject not yet init'd, manually free */
619 goto err1;
620 }
621
622 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
623 SYSFS_BRIDGE_PORT_ATTR);
624 if (err)
625 goto err2;
626
627 err = br_sysfs_addif(p);
628 if (err)
629 goto err2;
630
631 err = br_netpoll_enable(p);
632 if (err)
633 goto err3;
634
635 err = netdev_rx_handler_register(dev, br_get_rx_handler(dev), p);
636 if (err)
637 goto err4;
638
639 dev->priv_flags |= IFF_BRIDGE_PORT;
640
641 err = netdev_master_upper_dev_link(dev, br->dev, NULL, NULL, extack);
642 if (err)
643 goto err5;
644
645 err = nbp_switchdev_mark_set(p);
646 if (err)
647 goto err6;
648
649 dev_disable_lro(dev);
650
651 list_add_rcu(&p->list, &br->port_list);
652
653 nbp_update_port_count(br);
654
655 netdev_update_features(br->dev);
656
657 br_hr = br->dev->needed_headroom;
658 dev_hr = netdev_get_fwd_headroom(dev);
659 if (br_hr < dev_hr)
660 update_headroom(br, dev_hr);
661 else
662 netdev_set_rx_headroom(dev, br_hr);
663
664 if (br_fdb_insert(br, p, dev->dev_addr, 0))
665 netdev_err(dev, "failed insert local address bridge forwarding table\n");
666
667 if (br->dev->addr_assign_type != NET_ADDR_SET) {
668 /* Ask for permission to use this MAC address now, even if we
669 * don't end up choosing it below.
670 */
671 err = dev_pre_changeaddr_notify(br->dev, dev->dev_addr, extack);
672 if (err)
673 goto err7;
674 }
675
676 err = nbp_vlan_init(p, extack);
677 if (err) {
678 netdev_err(dev, "failed to initialize vlan filtering on this port\n");
679 goto err7;
680 }
681
682 spin_lock_bh(&br->lock);
683 changed_addr = br_stp_recalculate_bridge_id(br);
684
685 if (netif_running(dev) && netif_oper_up(dev) &&
686 (br->dev->flags & IFF_UP))
687 br_stp_enable_port(p);
688 spin_unlock_bh(&br->lock);
689
690 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
691
692 if (changed_addr)
693 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
694
695 br_mtu_auto_adjust(br);
696 br_set_gso_limits(br);
697
698 kobject_uevent(&p->kobj, KOBJ_ADD);
699
700 return 0;
701
702err7:
703 list_del_rcu(&p->list);
704 br_fdb_delete_by_port(br, p, 0, 1);
705 nbp_update_port_count(br);
706err6:
707 netdev_upper_dev_unlink(dev, br->dev);
708err5:
709 dev->priv_flags &= ~IFF_BRIDGE_PORT;
710 netdev_rx_handler_unregister(dev);
711err4:
712 br_netpoll_disable(p);
713err3:
714 sysfs_remove_link(br->ifobj, p->dev->name);
715err2:
716 kobject_put(&p->kobj);
717 dev_set_allmulti(dev, -1);
718err1:
719 dev_put(dev);
720 return err;
721}
722
723/* called with RTNL */
724int br_del_if(struct net_bridge *br, struct net_device *dev)
725{
726 struct net_bridge_port *p;
727 bool changed_addr;
728
729 p = br_port_get_rtnl(dev);
730 if (!p || p->br != br)
731 return -EINVAL;
732
733 /* Since more than one interface can be attached to a bridge,
734 * there still maybe an alternate path for netconsole to use;
735 * therefore there is no reason for a NETDEV_RELEASE event.
736 */
737 del_nbp(p);
738
739 br_mtu_auto_adjust(br);
740 br_set_gso_limits(br);
741
742 spin_lock_bh(&br->lock);
743 changed_addr = br_stp_recalculate_bridge_id(br);
744 spin_unlock_bh(&br->lock);
745
746 if (changed_addr)
747 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
748
749 netdev_update_features(br->dev);
750
751 return 0;
752}
753
754void br_port_flags_change(struct net_bridge_port *p, unsigned long mask)
755{
756 struct net_bridge *br = p->br;
757
758 if (mask & BR_AUTO_MASK)
759 nbp_update_port_count(br);
760
761 if (mask & BR_NEIGH_SUPPRESS)
762 br_recalculate_neigh_suppress_enabled(br);
763}
764
765bool br_port_flag_is_set(const struct net_device *dev, unsigned long flag)
766{
767 struct net_bridge_port *p;
768
769 p = br_port_get_rtnl_rcu(dev);
770 if (!p)
771 return false;
772
773 return p->flags & flag;
774}
775EXPORT_SYMBOL_GPL(br_port_flag_is_set);