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 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 } 144 145 static 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 } 155 156 static 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, BROPT_MULTICAST_ENABLED)) 166 br_multicast_join_snoopers(br); 167 168 return 0; 169 } 170 171 static void br_dev_set_multicast_list(struct net_device *dev) 172 { 173 } 174 175 static void br_dev_change_rx_flags(struct net_device *dev, int change) 176 { 177 if (change & IFF_PROMISC) 178 br_manage_promisc(netdev_priv(dev)); 179 } 180 181 static 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, BROPT_MULTICAST_ENABLED)) 189 br_multicast_leave_snoopers(br); 190 191 netif_stop_queue(dev); 192 193 return 0; 194 } 195 196 static 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, BROPT_MTU_SET_BY_USER, true); 204 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 205 /* remember the MTU in the rtable for PMTU */ 206 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 207 #endif 208 209 return 0; 210 } 211 212 /* Allow setting mac address to any valid ethernet address. */ 213 static 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->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(&br->lock); 228 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 229 /* Mac address will be changed in br_stp_change_bridge_id(). */ 230 br_stp_change_bridge_id(br, addr->sa_data); 231 } 232 spin_unlock_bh(&br->lock); 233 234 return 0; 235 } 236 237 static 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 } 244 245 static 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(pdev) || !netif_oper_up(pdev)) 260 continue; 261 262 if (__ethtool_get_link_ksettings(pdev, &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 } 275 276 static 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 285 static void br_poll_controller(struct net_device *br_dev) 286 { 287 } 288 289 static 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 } 297 298 static int __br_netpoll_enable(struct net_bridge_port *p) 299 { 300 struct netpoll *np; 301 int err; 302 303 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 304 if (!np) 305 return -ENOMEM; 306 307 err = __netpoll_setup(np, p->dev); 308 if (err) { 309 kfree(np); 310 return err; 311 } 312 313 p->np = np; 314 return err; 315 } 316 317 int 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 } 324 325 static 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 } 338 339 out: 340 return err; 341 342 fail: 343 br_netpoll_cleanup(dev); 344 goto out; 345 } 346 347 void 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 360 361 static 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, slave_dev, extack); 368 } 369 370 static 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, slave_dev); 375 } 376 377 static 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(ctx->dev)) 385 return -1; 386 387 br = netdev_priv(ctx->dev); 388 389 br_vlan_fill_forward_path_pvid(br, ctx, path); 390 391 f = br_fdb_find_rcu(br, ctx->daddr, 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 } 424 425 static 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 }; 430 431 static 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 }; 467 468 static const struct device_type br_type = { 469 .name = "bridge", 470 }; 471 472 void 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(&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(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