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 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 } 116 117 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 } 150 151 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 } 161 162 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 } 176 177 static void br_dev_set_multicast_list(struct net_device *dev) 178 { 179 } 180 181 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 } 186 187 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 } 201 202 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. */ 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 } 242 243 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 } 250 251 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 } 281 282 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 291 static void br_poll_controller(struct net_device *br_dev) 292 { 293 } 294 295 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 } 303 304 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 } 322 323 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 } 330 331 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 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 } 352 353 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 366 367 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 } 375 376 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 } 382 383 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 }; 477 478 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