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 *br = netdev_priv(dev); 31 struct net_bridge_fdb_entry *dst; 32 struct net_bridge_mdb_entry *mdst; 33 struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); 34 const struct nf_br_ops *nf_ops; 35 u8 state = BR_STATE_FORWARDING; 36 const unsigned char *dest; 37 u16 vid = 0; 38 39 memset(skb->cb, 0, sizeof(struct br_input_skb_cb)); 40 41 rcu_read_lock(); 42 nf_ops = rcu_dereference(nf_br_ops); 43 if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) { 44 rcu_read_unlock(); 45 return NETDEV_TX_OK; 46 } 47 48 u64_stats_update_begin(&brstats->syncp); 49 brstats->tx_packets++; 50 brstats->tx_bytes += skb->len; 51 u64_stats_update_end(&brstats->syncp); 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, &state)) 61 goto out; 62 63 if (IS_ENABLED(CONFIG_INET) && 64 (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) || 65 eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) && 66 br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) { 67 br_do_proxy_suppress_arp(skb, br, vid, NULL); 68 } else if (IS_ENABLED(CONFIG_IPV6) && 69 skb->protocol == htons(ETH_P_IPV6) && 70 br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) && 71 pskb_may_pull(skb, sizeof(struct ipv6hdr) + 72 sizeof(struct nd_msg)) && 73 ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) { 74 struct nd_msg *msg, _msg; 75 76 msg = br_is_nd_neigh_msg(skb, &_msg); 77 if (msg) 78 br_do_suppress_nd(skb, br, vid, NULL, msg); 79 } 80 81 dest = eth_hdr(skb)->h_dest; 82 if (is_broadcast_ether_addr(dest)) { 83 br_flood(br, skb, BR_PKT_BROADCAST, false, true); 84 } else if (is_multicast_ether_addr(dest)) { 85 if (unlikely(netpoll_tx_running(dev))) { 86 br_flood(br, skb, BR_PKT_MULTICAST, false, true); 87 goto out; 88 } 89 if (br_multicast_rcv(br, NULL, skb, vid)) { 90 kfree_skb(skb); 91 goto out; 92 } 93 94 mdst = br_mdb_get(br, skb, vid); 95 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && 96 br_multicast_querier_exists(br, eth_hdr(skb))) 97 br_multicast_flood(mdst, skb, false, true); 98 else 99 br_flood(br, skb, BR_PKT_MULTICAST, false, true); 100 } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) { 101 br_forward(dst->dst, skb, false, true); 102 } else { 103 br_flood(br, skb, BR_PKT_UNICAST, false, true); 104 } 105 out: 106 rcu_read_unlock(); 107 return NETDEV_TX_OK; 108 } 109 110 static struct lock_class_key bridge_netdev_addr_lock_key; 111 112 static void br_set_lockdep_class(struct net_device *dev) 113 { 114 lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key); 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 br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 123 if (!br->stats) 124 return -ENOMEM; 125 126 err = br_fdb_hash_init(br); 127 if (err) { 128 free_percpu(br->stats); 129 return err; 130 } 131 132 err = br_mdb_hash_init(br); 133 if (err) { 134 free_percpu(br->stats); 135 br_fdb_hash_fini(br); 136 return err; 137 } 138 139 err = br_vlan_init(br); 140 if (err) { 141 free_percpu(br->stats); 142 br_mdb_hash_fini(br); 143 br_fdb_hash_fini(br); 144 return err; 145 } 146 147 err = br_multicast_init_stats(br); 148 if (err) { 149 free_percpu(br->stats); 150 br_vlan_flush(br); 151 br_mdb_hash_fini(br); 152 br_fdb_hash_fini(br); 153 } 154 155 br_set_lockdep_class(dev); 156 return err; 157 } 158 159 static void br_dev_uninit(struct net_device *dev) 160 { 161 struct net_bridge *br = netdev_priv(dev); 162 163 br_multicast_dev_del(br); 164 br_multicast_uninit_stats(br); 165 br_vlan_flush(br); 166 br_mdb_hash_fini(br); 167 br_fdb_hash_fini(br); 168 free_percpu(br->stats); 169 } 170 171 static int br_dev_open(struct net_device *dev) 172 { 173 struct net_bridge *br = netdev_priv(dev); 174 175 netdev_update_features(dev); 176 netif_start_queue(dev); 177 br_stp_enable_bridge(br); 178 br_multicast_open(br); 179 180 return 0; 181 } 182 183 static void br_dev_set_multicast_list(struct net_device *dev) 184 { 185 } 186 187 static void br_dev_change_rx_flags(struct net_device *dev, int change) 188 { 189 if (change & IFF_PROMISC) 190 br_manage_promisc(netdev_priv(dev)); 191 } 192 193 static int br_dev_stop(struct net_device *dev) 194 { 195 struct net_bridge *br = netdev_priv(dev); 196 197 br_stp_disable_bridge(br); 198 br_multicast_stop(br); 199 200 netif_stop_queue(dev); 201 202 return 0; 203 } 204 205 static void br_get_stats64(struct net_device *dev, 206 struct rtnl_link_stats64 *stats) 207 { 208 struct net_bridge *br = netdev_priv(dev); 209 struct pcpu_sw_netstats tmp, sum = { 0 }; 210 unsigned int cpu; 211 212 for_each_possible_cpu(cpu) { 213 unsigned int start; 214 const struct pcpu_sw_netstats *bstats 215 = per_cpu_ptr(br->stats, cpu); 216 do { 217 start = u64_stats_fetch_begin_irq(&bstats->syncp); 218 memcpy(&tmp, bstats, sizeof(tmp)); 219 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start)); 220 sum.tx_bytes += tmp.tx_bytes; 221 sum.tx_packets += tmp.tx_packets; 222 sum.rx_bytes += tmp.rx_bytes; 223 sum.rx_packets += tmp.rx_packets; 224 } 225 226 stats->tx_bytes = sum.tx_bytes; 227 stats->tx_packets = sum.tx_packets; 228 stats->rx_bytes = sum.rx_bytes; 229 stats->rx_packets = sum.rx_packets; 230 } 231 232 static int br_change_mtu(struct net_device *dev, int new_mtu) 233 { 234 struct net_bridge *br = netdev_priv(dev); 235 236 dev->mtu = new_mtu; 237 238 /* this flag will be cleared if the MTU was automatically adjusted */ 239 br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true); 240 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 241 /* remember the MTU in the rtable for PMTU */ 242 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 243 #endif 244 245 return 0; 246 } 247 248 /* Allow setting mac address to any valid ethernet address. */ 249 static int br_set_mac_address(struct net_device *dev, void *p) 250 { 251 struct net_bridge *br = netdev_priv(dev); 252 struct sockaddr *addr = p; 253 254 if (!is_valid_ether_addr(addr->sa_data)) 255 return -EADDRNOTAVAIL; 256 257 /* dev_set_mac_addr() can be called by a master device on bridge's 258 * NETDEV_UNREGISTER, but since it's being destroyed do nothing 259 */ 260 if (dev->reg_state != NETREG_REGISTERED) 261 return -EBUSY; 262 263 spin_lock_bh(&br->lock); 264 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 265 /* Mac address will be changed in br_stp_change_bridge_id(). */ 266 br_stp_change_bridge_id(br, addr->sa_data); 267 } 268 spin_unlock_bh(&br->lock); 269 270 return 0; 271 } 272 273 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 274 { 275 strlcpy(info->driver, "bridge", sizeof(info->driver)); 276 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 277 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 278 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 279 } 280 281 static int br_get_link_ksettings(struct net_device *dev, 282 struct ethtool_link_ksettings *cmd) 283 { 284 struct net_bridge *br = netdev_priv(dev); 285 struct net_bridge_port *p; 286 287 cmd->base.duplex = DUPLEX_UNKNOWN; 288 cmd->base.port = PORT_OTHER; 289 cmd->base.speed = SPEED_UNKNOWN; 290 291 list_for_each_entry(p, &br->port_list, list) { 292 struct ethtool_link_ksettings ecmd; 293 struct net_device *pdev = p->dev; 294 295 if (!netif_running(pdev) || !netif_oper_up(pdev)) 296 continue; 297 298 if (__ethtool_get_link_ksettings(pdev, &ecmd)) 299 continue; 300 301 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN) 302 continue; 303 304 if (cmd->base.speed == (__u32)SPEED_UNKNOWN || 305 cmd->base.speed < ecmd.base.speed) 306 cmd->base.speed = ecmd.base.speed; 307 } 308 309 return 0; 310 } 311 312 static netdev_features_t br_fix_features(struct net_device *dev, 313 netdev_features_t features) 314 { 315 struct net_bridge *br = netdev_priv(dev); 316 317 return br_features_recompute(br, features); 318 } 319 320 #ifdef CONFIG_NET_POLL_CONTROLLER 321 static void br_poll_controller(struct net_device *br_dev) 322 { 323 } 324 325 static void br_netpoll_cleanup(struct net_device *dev) 326 { 327 struct net_bridge *br = netdev_priv(dev); 328 struct net_bridge_port *p; 329 330 list_for_each_entry(p, &br->port_list, list) 331 br_netpoll_disable(p); 332 } 333 334 static int __br_netpoll_enable(struct net_bridge_port *p) 335 { 336 struct netpoll *np; 337 int err; 338 339 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 340 if (!np) 341 return -ENOMEM; 342 343 err = __netpoll_setup(np, p->dev); 344 if (err) { 345 kfree(np); 346 return err; 347 } 348 349 p->np = np; 350 return err; 351 } 352 353 int br_netpoll_enable(struct net_bridge_port *p) 354 { 355 if (!p->br->dev->npinfo) 356 return 0; 357 358 return __br_netpoll_enable(p); 359 } 360 361 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 362 { 363 struct net_bridge *br = netdev_priv(dev); 364 struct net_bridge_port *p; 365 int err = 0; 366 367 list_for_each_entry(p, &br->port_list, list) { 368 if (!p->dev) 369 continue; 370 err = __br_netpoll_enable(p); 371 if (err) 372 goto fail; 373 } 374 375 out: 376 return err; 377 378 fail: 379 br_netpoll_cleanup(dev); 380 goto out; 381 } 382 383 void br_netpoll_disable(struct net_bridge_port *p) 384 { 385 struct netpoll *np = p->np; 386 387 if (!np) 388 return; 389 390 p->np = NULL; 391 392 __netpoll_free(np); 393 } 394 395 #endif 396 397 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev, 398 struct netlink_ext_ack *extack) 399 400 { 401 struct net_bridge *br = netdev_priv(dev); 402 403 return br_add_if(br, slave_dev, extack); 404 } 405 406 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 407 { 408 struct net_bridge *br = netdev_priv(dev); 409 410 return br_del_if(br, slave_dev); 411 } 412 413 static const struct ethtool_ops br_ethtool_ops = { 414 .get_drvinfo = br_getinfo, 415 .get_link = ethtool_op_get_link, 416 .get_link_ksettings = br_get_link_ksettings, 417 }; 418 419 static const struct net_device_ops br_netdev_ops = { 420 .ndo_open = br_dev_open, 421 .ndo_stop = br_dev_stop, 422 .ndo_init = br_dev_init, 423 .ndo_uninit = br_dev_uninit, 424 .ndo_start_xmit = br_dev_xmit, 425 .ndo_get_stats64 = br_get_stats64, 426 .ndo_set_mac_address = br_set_mac_address, 427 .ndo_set_rx_mode = br_dev_set_multicast_list, 428 .ndo_change_rx_flags = br_dev_change_rx_flags, 429 .ndo_change_mtu = br_change_mtu, 430 .ndo_do_ioctl = br_dev_ioctl, 431 #ifdef CONFIG_NET_POLL_CONTROLLER 432 .ndo_netpoll_setup = br_netpoll_setup, 433 .ndo_netpoll_cleanup = br_netpoll_cleanup, 434 .ndo_poll_controller = br_poll_controller, 435 #endif 436 .ndo_add_slave = br_add_slave, 437 .ndo_del_slave = br_del_slave, 438 .ndo_fix_features = br_fix_features, 439 .ndo_fdb_add = br_fdb_add, 440 .ndo_fdb_del = br_fdb_delete, 441 .ndo_fdb_dump = br_fdb_dump, 442 .ndo_fdb_get = br_fdb_get, 443 .ndo_bridge_getlink = br_getlink, 444 .ndo_bridge_setlink = br_setlink, 445 .ndo_bridge_dellink = br_dellink, 446 .ndo_features_check = passthru_features_check, 447 }; 448 449 static struct device_type br_type = { 450 .name = "bridge", 451 }; 452 453 void br_dev_setup(struct net_device *dev) 454 { 455 struct net_bridge *br = netdev_priv(dev); 456 457 eth_hw_addr_random(dev); 458 ether_setup(dev); 459 460 dev->netdev_ops = &br_netdev_ops; 461 dev->needs_free_netdev = true; 462 dev->ethtool_ops = &br_ethtool_ops; 463 SET_NETDEV_DEVTYPE(dev, &br_type); 464 dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE; 465 466 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 467 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; 468 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 469 NETIF_F_HW_VLAN_STAG_TX; 470 dev->vlan_features = COMMON_FEATURES; 471 472 br->dev = dev; 473 spin_lock_init(&br->lock); 474 INIT_LIST_HEAD(&br->port_list); 475 INIT_HLIST_HEAD(&br->fdb_list); 476 #if IS_ENABLED(CONFIG_BRIDGE_MRP) 477 INIT_LIST_HEAD(&br->mrp_list); 478 #endif 479 spin_lock_init(&br->hash_lock); 480 481 br->bridge_id.prio[0] = 0x80; 482 br->bridge_id.prio[1] = 0x00; 483 484 ether_addr_copy(br->group_addr, eth_stp_addr); 485 486 br->stp_enabled = BR_NO_STP; 487 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 488 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; 489 490 br->designated_root = br->bridge_id; 491 br->bridge_max_age = br->max_age = 20 * HZ; 492 br->bridge_hello_time = br->hello_time = 2 * HZ; 493 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 494 br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME; 495 dev->max_mtu = ETH_MAX_MTU; 496 497 br_netfilter_rtable_init(br); 498 br_stp_timer_init(br); 499 br_multicast_init(br); 500 INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup); 501 } 502