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); 778