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 */ 28 netdev_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, 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, 1, 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, br_vlan_group_rcu(br), skb, &vid, 61 &state, &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, 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, BROPT_NEIGH_SUPPRESS_ENABLED) && 72 pskb_may_pull(skb, 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, &_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(dest)) { 84 br_flood(br, skb, BR_PKT_BROADCAST, false, true, vid); 85 } else if (is_multicast_ether_addr(dest)) { 86 if (unlikely(netpoll_tx_running(dev))) { 87 br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid); 88 goto out; 89 } 90 if (br_multicast_rcv(&brmctx, &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_hdr(skb), mdst)) 98 br_multicast_flood(mdst, skb, brmctx, false, true); 99 else 100 br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid); 101 } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) { 102 br_forward(dst->dst, skb, false, true); 103 } else { 104 br_flood(br, skb, BR_PKT_UNICAST, false, true, vid); 105 } 106 out: 107 rcu_read_unlock(); 108 return NETDEV_TX_OK; 109 } 110 111 static struct lock_class_key bridge_netdev_addr_lock_key; 112 113 static void br_set_lockdep_class(struct net_device *dev) 114 { 115 lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key); 116 } 117 118 static int br_dev_init(struct net_device *dev) 119 { 120 struct net_bridge *br = netdev_priv(dev); 121 int err; 122 123 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 124 if (!dev->tstats) 125 return -ENOMEM; 126 127 err = br_fdb_hash_init(br); 128 if (err) { 129 free_percpu(dev->tstats); 130 return err; 131 } 132 133 err = br_mdb_hash_init(br); 134 if (err) { 135 free_percpu(dev->tstats); 136 br_fdb_hash_fini(br); 137 return err; 138 } 139 140 err = br_vlan_init(br); 141 if (err) { 142 free_percpu(dev->tstats); 143 br_mdb_hash_fini(br); 144 br_fdb_hash_fini(br); 145 return err; 146 } 147 148 err = br_multicast_init_stats(br); 149 if (err) { 150 free_percpu(dev->tstats); 151 br_vlan_flush(br); 152 br_mdb_hash_fini(br); 153 br_fdb_hash_fini(br); 154 } 155 156 br_set_lockdep_class(dev); 157 return err; 158 } 159 160 static void br_dev_uninit(struct net_device *dev) 161 { 162 struct net_bridge *br = netdev_priv(dev); 163 164 br_multicast_dev_del(br); 165 br_multicast_uninit_stats(br); 166 br_vlan_flush(br); 167 br_mdb_hash_fini(br); 168 br_fdb_hash_fini(br); 169 free_percpu(dev->tstats); 170 } 171 172 static int br_dev_open(struct net_device *dev) 173 { 174 struct net_bridge *br = netdev_priv(dev); 175 176 netdev_update_features(dev); 177 netif_start_queue(dev); 178 br_stp_enable_bridge(br); 179 br_multicast_open(br); 180 181 if (br_opt_get(br, BROPT_MULTICAST_ENABLED)) 182 br_multicast_join_snoopers(br); 183 184 return 0; 185 } 186 187 static void br_dev_set_multicast_list(struct net_device *dev) 188 { 189 } 190 191 static void br_dev_change_rx_flags(struct net_device *dev, int change) 192 { 193 if (change & IFF_PROMISC) 194 br_manage_promisc(netdev_priv(dev)); 195 } 196 197 static int br_dev_stop(struct net_device *dev) 198 { 199 struct net_bridge *br = netdev_priv(dev); 200 201 br_stp_disable_bridge(br); 202 br_multicast_stop(br); 203 204 if (br_opt_get(br, BROPT_MULTICAST_ENABLED)) 205 br_multicast_leave_snoopers(br); 206 207 netif_stop_queue(dev); 208 209 return 0; 210 } 211 212 static int br_change_mtu(struct net_device *dev, int new_mtu) 213 { 214 struct net_bridge *br = netdev_priv(dev); 215 216 dev->mtu = new_mtu; 217 218 /* this flag will be cleared if the MTU was automatically adjusted */ 219 br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true); 220 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 221 /* remember the MTU in the rtable for PMTU */ 222 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 223 #endif 224 225 return 0; 226 } 227 228 /* Allow setting mac address to any valid ethernet address. */ 229 static int br_set_mac_address(struct net_device *dev, void *p) 230 { 231 struct net_bridge *br = netdev_priv(dev); 232 struct sockaddr *addr = p; 233 234 if (!is_valid_ether_addr(addr->sa_data)) 235 return -EADDRNOTAVAIL; 236 237 /* dev_set_mac_addr() can be called by a master device on bridge's 238 * NETDEV_UNREGISTER, but since it's being destroyed do nothing 239 */ 240 if (dev->reg_state != NETREG_REGISTERED) 241 return -EBUSY; 242 243 spin_lock_bh(&br->lock); 244 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 245 /* Mac address will be changed in br_stp_change_bridge_id(). */ 246 br_stp_change_bridge_id(br, addr->sa_data); 247 } 248 spin_unlock_bh(&br->lock); 249 250 return 0; 251 } 252 253 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 254 { 255 strscpy(info->driver, "bridge", sizeof(info->driver)); 256 strscpy(info->version, BR_VERSION, sizeof(info->version)); 257 strscpy(info->fw_version, "N/A", sizeof(info->fw_version)); 258 strscpy(info->bus_info, "N/A", sizeof(info->bus_info)); 259 } 260 261 static int br_get_link_ksettings(struct net_device *dev, 262 struct ethtool_link_ksettings *cmd) 263 { 264 struct net_bridge *br = netdev_priv(dev); 265 struct net_bridge_port *p; 266 267 cmd->base.duplex = DUPLEX_UNKNOWN; 268 cmd->base.port = PORT_OTHER; 269 cmd->base.speed = SPEED_UNKNOWN; 270 271 list_for_each_entry(p, &br->port_list, list) { 272 struct ethtool_link_ksettings ecmd; 273 struct net_device *pdev = p->dev; 274 275 if (!netif_running(pdev) || !netif_oper_up(pdev)) 276 continue; 277 278 if (__ethtool_get_link_ksettings(pdev, &ecmd)) 279 continue; 280 281 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN) 282 continue; 283 284 if (cmd->base.speed == (__u32)SPEED_UNKNOWN || 285 cmd->base.speed < ecmd.base.speed) 286 cmd->base.speed = ecmd.base.speed; 287 } 288 289 return 0; 290 } 291 292 static netdev_features_t br_fix_features(struct net_device *dev, 293 netdev_features_t features) 294 { 295 struct net_bridge *br = netdev_priv(dev); 296 297 return br_features_recompute(br, features); 298 } 299 300 #ifdef CONFIG_NET_POLL_CONTROLLER 301 static void br_poll_controller(struct net_device *br_dev) 302 { 303 } 304 305 static void br_netpoll_cleanup(struct net_device *dev) 306 { 307 struct net_bridge *br = netdev_priv(dev); 308 struct net_bridge_port *p; 309 310 list_for_each_entry(p, &br->port_list, list) 311 br_netpoll_disable(p); 312 } 313 314 static int __br_netpoll_enable(struct net_bridge_port *p) 315 { 316 struct netpoll *np; 317 int err; 318 319 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 320 if (!np) 321 return -ENOMEM; 322 323 err = __netpoll_setup(np, p->dev); 324 if (err) { 325 kfree(np); 326 return err; 327 } 328 329 p->np = np; 330 return err; 331 } 332 333 int br_netpoll_enable(struct net_bridge_port *p) 334 { 335 if (!p->br->dev->npinfo) 336 return 0; 337 338 return __br_netpoll_enable(p); 339 } 340 341 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 342 { 343 struct net_bridge *br = netdev_priv(dev); 344 struct net_bridge_port *p; 345 int err = 0; 346 347 list_for_each_entry(p, &br->port_list, list) { 348 if (!p->dev) 349 continue; 350 err = __br_netpoll_enable(p); 351 if (err) 352 goto fail; 353 } 354 355 out: 356 return err; 357 358 fail: 359 br_netpoll_cleanup(dev); 360 goto out; 361 } 362 363 void br_netpoll_disable(struct net_bridge_port *p) 364 { 365 struct netpoll *np = p->np; 366 367 if (!np) 368 return; 369 370 p->np = NULL; 371 372 __netpoll_free(np); 373 } 374 375 #endif 376 377 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev, 378 struct netlink_ext_ack *extack) 379 380 { 381 struct net_bridge *br = netdev_priv(dev); 382 383 return br_add_if(br, slave_dev, extack); 384 } 385 386 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 387 { 388 struct net_bridge *br = netdev_priv(dev); 389 390 return br_del_if(br, slave_dev); 391 } 392 393 static int br_fill_forward_path(struct net_device_path_ctx *ctx, 394 struct net_device_path *path) 395 { 396 struct net_bridge_fdb_entry *f; 397 struct net_bridge_port *dst; 398 struct net_bridge *br; 399 400 if (netif_is_bridge_port(ctx->dev)) 401 return -1; 402 403 br = netdev_priv(ctx->dev); 404 405 br_vlan_fill_forward_path_pvid(br, ctx, path); 406 407 f = br_fdb_find_rcu(br, ctx->daddr, path->bridge.vlan_id); 408 if (!f || !f->dst) 409 return -1; 410 411 dst = READ_ONCE(f->dst); 412 if (!dst) 413 return -1; 414 415 if (br_vlan_fill_forward_path_mode(br, dst, path)) 416 return -1; 417 418 path->type = DEV_PATH_BRIDGE; 419 path->dev = dst->br->dev; 420 ctx->dev = dst->dev; 421 422 switch (path->bridge.vlan_mode) { 423 case DEV_PATH_BR_VLAN_TAG: 424 if (ctx->num_vlans >= ARRAY_SIZE(ctx->vlan)) 425 return -ENOSPC; 426 ctx->vlan[ctx->num_vlans].id = path->bridge.vlan_id; 427 ctx->vlan[ctx->num_vlans].proto = path->bridge.vlan_proto; 428 ctx->num_vlans++; 429 break; 430 case DEV_PATH_BR_VLAN_UNTAG_HW: 431 case DEV_PATH_BR_VLAN_UNTAG: 432 ctx->num_vlans--; 433 break; 434 case DEV_PATH_BR_VLAN_KEEP: 435 break; 436 } 437 438 return 0; 439 } 440 441 static const struct ethtool_ops br_ethtool_ops = { 442 .get_drvinfo = br_getinfo, 443 .get_link = ethtool_op_get_link, 444 .get_link_ksettings = br_get_link_ksettings, 445 }; 446 447 static const struct net_device_ops br_netdev_ops = { 448 .ndo_open = br_dev_open, 449 .ndo_stop = br_dev_stop, 450 .ndo_init = br_dev_init, 451 .ndo_uninit = br_dev_uninit, 452 .ndo_start_xmit = br_dev_xmit, 453 .ndo_get_stats64 = dev_get_tstats64, 454 .ndo_set_mac_address = br_set_mac_address, 455 .ndo_set_rx_mode = br_dev_set_multicast_list, 456 .ndo_change_rx_flags = br_dev_change_rx_flags, 457 .ndo_change_mtu = br_change_mtu, 458 .ndo_siocdevprivate = br_dev_siocdevprivate, 459 #ifdef CONFIG_NET_POLL_CONTROLLER 460 .ndo_netpoll_setup = br_netpoll_setup, 461 .ndo_netpoll_cleanup = br_netpoll_cleanup, 462 .ndo_poll_controller = br_poll_controller, 463 #endif 464 .ndo_add_slave = br_add_slave, 465 .ndo_del_slave = br_del_slave, 466 .ndo_fix_features = br_fix_features, 467 .ndo_fdb_add = br_fdb_add, 468 .ndo_fdb_del = br_fdb_delete, 469 .ndo_fdb_del_bulk = br_fdb_delete_bulk, 470 .ndo_fdb_dump = br_fdb_dump, 471 .ndo_fdb_get = br_fdb_get, 472 .ndo_mdb_add = br_mdb_add, 473 .ndo_mdb_del = br_mdb_del, 474 .ndo_mdb_del_bulk = br_mdb_del_bulk, 475 .ndo_mdb_dump = br_mdb_dump, 476 .ndo_mdb_get = br_mdb_get, 477 .ndo_bridge_getlink = br_getlink, 478 .ndo_bridge_setlink = br_setlink, 479 .ndo_bridge_dellink = br_dellink, 480 .ndo_features_check = passthru_features_check, 481 .ndo_fill_forward_path = br_fill_forward_path, 482 }; 483 484 static struct device_type br_type = { 485 .name = "bridge", 486 }; 487 488 void br_dev_setup(struct net_device *dev) 489 { 490 struct net_bridge *br = netdev_priv(dev); 491 492 eth_hw_addr_random(dev); 493 ether_setup(dev); 494 495 dev->netdev_ops = &br_netdev_ops; 496 dev->needs_free_netdev = true; 497 dev->ethtool_ops = &br_ethtool_ops; 498 SET_NETDEV_DEVTYPE(dev, &br_type); 499 dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE; 500 501 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 502 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; 503 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 504 NETIF_F_HW_VLAN_STAG_TX; 505 dev->vlan_features = COMMON_FEATURES; 506 507 br->dev = dev; 508 spin_lock_init(&br->lock); 509 INIT_LIST_HEAD(&br->port_list); 510 INIT_HLIST_HEAD(&br->fdb_list); 511 INIT_HLIST_HEAD(&br->frame_type_list); 512 #if IS_ENABLED(CONFIG_BRIDGE_MRP) 513 INIT_HLIST_HEAD(&br->mrp_list); 514 #endif 515 #if IS_ENABLED(CONFIG_BRIDGE_CFM) 516 INIT_HLIST_HEAD(&br->mep_list); 517 #endif 518 spin_lock_init(&br->hash_lock); 519 520 br->bridge_id.prio[0] = 0x80; 521 br->bridge_id.prio[1] = 0x00; 522 523 ether_addr_copy(br->group_addr, eth_stp_addr); 524 525 br->stp_enabled = BR_NO_STP; 526 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 527 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; 528 529 br->designated_root = br->bridge_id; 530 br->bridge_max_age = br->max_age = 20 * HZ; 531 br->bridge_hello_time = br->hello_time = 2 * HZ; 532 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 533 br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME; 534 dev->max_mtu = ETH_MAX_MTU; 535 536 br_netfilter_rtable_init(br); 537 br_stp_timer_init(br); 538 br_multicast_init(br); 539 INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup); 540 } 541