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 rcu_read_lock(); 40 nf_ops = rcu_dereference(nf_br_ops); 41 if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) { 42 rcu_read_unlock(); 43 return NETDEV_TX_OK; 44 } 45 46 u64_stats_update_begin(&brstats->syncp); 47 brstats->tx_packets++; 48 brstats->tx_bytes += skb->len; 49 u64_stats_update_end(&brstats->syncp); 50 51 br_switchdev_frame_unmark(skb); 52 BR_INPUT_SKB_CB(skb)->brdev = dev; 53 BR_INPUT_SKB_CB(skb)->frag_max_size = 0; 54 55 skb_reset_mac_header(skb); 56 skb_pull(skb, ETH_HLEN); 57 58 if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid, &state)) 59 goto out; 60 61 if (IS_ENABLED(CONFIG_INET) && 62 (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) || 63 eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) && 64 br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) { 65 br_do_proxy_suppress_arp(skb, br, vid, NULL); 66 } else if (IS_ENABLED(CONFIG_IPV6) && 67 skb->protocol == htons(ETH_P_IPV6) && 68 br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) && 69 pskb_may_pull(skb, sizeof(struct ipv6hdr) + 70 sizeof(struct nd_msg)) && 71 ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) { 72 struct nd_msg *msg, _msg; 73 74 msg = br_is_nd_neigh_msg(skb, &_msg); 75 if (msg) 76 br_do_suppress_nd(skb, br, vid, NULL, msg); 77 } 78 79 dest = eth_hdr(skb)->h_dest; 80 if (is_broadcast_ether_addr(dest)) { 81 br_flood(br, skb, BR_PKT_BROADCAST, false, true); 82 } else if (is_multicast_ether_addr(dest)) { 83 if (unlikely(netpoll_tx_running(dev))) { 84 br_flood(br, skb, BR_PKT_MULTICAST, false, true); 85 goto out; 86 } 87 if (br_multicast_rcv(br, NULL, skb, vid)) { 88 kfree_skb(skb); 89 goto out; 90 } 91 92 mdst = br_mdb_get(br, skb, vid); 93 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && 94 br_multicast_querier_exists(br, eth_hdr(skb))) 95 br_multicast_flood(mdst, skb, false, true); 96 else 97 br_flood(br, skb, BR_PKT_MULTICAST, false, true); 98 } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) { 99 br_forward(dst->dst, skb, false, true); 100 } else { 101 br_flood(br, skb, BR_PKT_UNICAST, false, true); 102 } 103 out: 104 rcu_read_unlock(); 105 return NETDEV_TX_OK; 106 } 107 108 static struct lock_class_key bridge_netdev_addr_lock_key; 109 110 static void br_set_lockdep_class(struct net_device *dev) 111 { 112 lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key); 113 } 114 115 static int br_dev_init(struct net_device *dev) 116 { 117 struct net_bridge *br = netdev_priv(dev); 118 int err; 119 120 br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 121 if (!br->stats) 122 return -ENOMEM; 123 124 err = br_fdb_hash_init(br); 125 if (err) { 126 free_percpu(br->stats); 127 return err; 128 } 129 130 err = br_mdb_hash_init(br); 131 if (err) { 132 free_percpu(br->stats); 133 br_fdb_hash_fini(br); 134 return err; 135 } 136 137 err = br_vlan_init(br); 138 if (err) { 139 free_percpu(br->stats); 140 br_mdb_hash_fini(br); 141 br_fdb_hash_fini(br); 142 return err; 143 } 144 145 err = br_multicast_init_stats(br); 146 if (err) { 147 free_percpu(br->stats); 148 br_vlan_flush(br); 149 br_mdb_hash_fini(br); 150 br_fdb_hash_fini(br); 151 } 152 153 br_set_lockdep_class(dev); 154 return err; 155 } 156 157 static void br_dev_uninit(struct net_device *dev) 158 { 159 struct net_bridge *br = netdev_priv(dev); 160 161 br_multicast_dev_del(br); 162 br_multicast_uninit_stats(br); 163 br_vlan_flush(br); 164 br_mdb_hash_fini(br); 165 br_fdb_hash_fini(br); 166 free_percpu(br->stats); 167 } 168 169 static int br_dev_open(struct net_device *dev) 170 { 171 struct net_bridge *br = netdev_priv(dev); 172 173 netdev_update_features(dev); 174 netif_start_queue(dev); 175 br_stp_enable_bridge(br); 176 br_multicast_open(br); 177 178 return 0; 179 } 180 181 static void br_dev_set_multicast_list(struct net_device *dev) 182 { 183 } 184 185 static void br_dev_change_rx_flags(struct net_device *dev, int change) 186 { 187 if (change & IFF_PROMISC) 188 br_manage_promisc(netdev_priv(dev)); 189 } 190 191 static int br_dev_stop(struct net_device *dev) 192 { 193 struct net_bridge *br = netdev_priv(dev); 194 195 br_stp_disable_bridge(br); 196 br_multicast_stop(br); 197 198 netif_stop_queue(dev); 199 200 return 0; 201 } 202 203 static void br_get_stats64(struct net_device *dev, 204 struct rtnl_link_stats64 *stats) 205 { 206 struct net_bridge *br = netdev_priv(dev); 207 struct pcpu_sw_netstats tmp, sum = { 0 }; 208 unsigned int cpu; 209 210 for_each_possible_cpu(cpu) { 211 unsigned int start; 212 const struct pcpu_sw_netstats *bstats 213 = per_cpu_ptr(br->stats, cpu); 214 do { 215 start = u64_stats_fetch_begin_irq(&bstats->syncp); 216 memcpy(&tmp, bstats, sizeof(tmp)); 217 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start)); 218 sum.tx_bytes += tmp.tx_bytes; 219 sum.tx_packets += tmp.tx_packets; 220 sum.rx_bytes += tmp.rx_bytes; 221 sum.rx_packets += tmp.rx_packets; 222 } 223 224 stats->tx_bytes = sum.tx_bytes; 225 stats->tx_packets = sum.tx_packets; 226 stats->rx_bytes = sum.rx_bytes; 227 stats->rx_packets = sum.rx_packets; 228 } 229 230 static int br_change_mtu(struct net_device *dev, int new_mtu) 231 { 232 struct net_bridge *br = netdev_priv(dev); 233 234 dev->mtu = new_mtu; 235 236 /* this flag will be cleared if the MTU was automatically adjusted */ 237 br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true); 238 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 239 /* remember the MTU in the rtable for PMTU */ 240 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 241 #endif 242 243 return 0; 244 } 245 246 /* Allow setting mac address to any valid ethernet address. */ 247 static int br_set_mac_address(struct net_device *dev, void *p) 248 { 249 struct net_bridge *br = netdev_priv(dev); 250 struct sockaddr *addr = p; 251 252 if (!is_valid_ether_addr(addr->sa_data)) 253 return -EADDRNOTAVAIL; 254 255 /* dev_set_mac_addr() can be called by a master device on bridge's 256 * NETDEV_UNREGISTER, but since it's being destroyed do nothing 257 */ 258 if (dev->reg_state != NETREG_REGISTERED) 259 return -EBUSY; 260 261 spin_lock_bh(&br->lock); 262 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 263 /* Mac address will be changed in br_stp_change_bridge_id(). */ 264 br_stp_change_bridge_id(br, addr->sa_data); 265 } 266 spin_unlock_bh(&br->lock); 267 268 return 0; 269 } 270 271 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 272 { 273 strlcpy(info->driver, "bridge", sizeof(info->driver)); 274 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 275 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 276 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 277 } 278 279 static int br_get_link_ksettings(struct net_device *dev, 280 struct ethtool_link_ksettings *cmd) 281 { 282 struct net_bridge *br = netdev_priv(dev); 283 struct net_bridge_port *p; 284 285 cmd->base.duplex = DUPLEX_UNKNOWN; 286 cmd->base.port = PORT_OTHER; 287 cmd->base.speed = SPEED_UNKNOWN; 288 289 list_for_each_entry(p, &br->port_list, list) { 290 struct ethtool_link_ksettings ecmd; 291 struct net_device *pdev = p->dev; 292 293 if (!netif_running(pdev) || !netif_oper_up(pdev)) 294 continue; 295 296 if (__ethtool_get_link_ksettings(pdev, &ecmd)) 297 continue; 298 299 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN) 300 continue; 301 302 if (cmd->base.speed == (__u32)SPEED_UNKNOWN || 303 cmd->base.speed < ecmd.base.speed) 304 cmd->base.speed = ecmd.base.speed; 305 } 306 307 return 0; 308 } 309 310 static netdev_features_t br_fix_features(struct net_device *dev, 311 netdev_features_t features) 312 { 313 struct net_bridge *br = netdev_priv(dev); 314 315 return br_features_recompute(br, features); 316 } 317 318 #ifdef CONFIG_NET_POLL_CONTROLLER 319 static void br_poll_controller(struct net_device *br_dev) 320 { 321 } 322 323 static void br_netpoll_cleanup(struct net_device *dev) 324 { 325 struct net_bridge *br = netdev_priv(dev); 326 struct net_bridge_port *p; 327 328 list_for_each_entry(p, &br->port_list, list) 329 br_netpoll_disable(p); 330 } 331 332 static int __br_netpoll_enable(struct net_bridge_port *p) 333 { 334 struct netpoll *np; 335 int err; 336 337 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 338 if (!np) 339 return -ENOMEM; 340 341 err = __netpoll_setup(np, p->dev); 342 if (err) { 343 kfree(np); 344 return err; 345 } 346 347 p->np = np; 348 return err; 349 } 350 351 int br_netpoll_enable(struct net_bridge_port *p) 352 { 353 if (!p->br->dev->npinfo) 354 return 0; 355 356 return __br_netpoll_enable(p); 357 } 358 359 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 360 { 361 struct net_bridge *br = netdev_priv(dev); 362 struct net_bridge_port *p; 363 int err = 0; 364 365 list_for_each_entry(p, &br->port_list, list) { 366 if (!p->dev) 367 continue; 368 err = __br_netpoll_enable(p); 369 if (err) 370 goto fail; 371 } 372 373 out: 374 return err; 375 376 fail: 377 br_netpoll_cleanup(dev); 378 goto out; 379 } 380 381 void br_netpoll_disable(struct net_bridge_port *p) 382 { 383 struct netpoll *np = p->np; 384 385 if (!np) 386 return; 387 388 p->np = NULL; 389 390 __netpoll_free(np); 391 } 392 393 #endif 394 395 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev, 396 struct netlink_ext_ack *extack) 397 398 { 399 struct net_bridge *br = netdev_priv(dev); 400 401 return br_add_if(br, slave_dev, extack); 402 } 403 404 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 405 { 406 struct net_bridge *br = netdev_priv(dev); 407 408 return br_del_if(br, slave_dev); 409 } 410 411 static const struct ethtool_ops br_ethtool_ops = { 412 .get_drvinfo = br_getinfo, 413 .get_link = ethtool_op_get_link, 414 .get_link_ksettings = br_get_link_ksettings, 415 }; 416 417 static const struct net_device_ops br_netdev_ops = { 418 .ndo_open = br_dev_open, 419 .ndo_stop = br_dev_stop, 420 .ndo_init = br_dev_init, 421 .ndo_uninit = br_dev_uninit, 422 .ndo_start_xmit = br_dev_xmit, 423 .ndo_get_stats64 = br_get_stats64, 424 .ndo_set_mac_address = br_set_mac_address, 425 .ndo_set_rx_mode = br_dev_set_multicast_list, 426 .ndo_change_rx_flags = br_dev_change_rx_flags, 427 .ndo_change_mtu = br_change_mtu, 428 .ndo_do_ioctl = br_dev_ioctl, 429 #ifdef CONFIG_NET_POLL_CONTROLLER 430 .ndo_netpoll_setup = br_netpoll_setup, 431 .ndo_netpoll_cleanup = br_netpoll_cleanup, 432 .ndo_poll_controller = br_poll_controller, 433 #endif 434 .ndo_add_slave = br_add_slave, 435 .ndo_del_slave = br_del_slave, 436 .ndo_fix_features = br_fix_features, 437 .ndo_fdb_add = br_fdb_add, 438 .ndo_fdb_del = br_fdb_delete, 439 .ndo_fdb_dump = br_fdb_dump, 440 .ndo_fdb_get = br_fdb_get, 441 .ndo_bridge_getlink = br_getlink, 442 .ndo_bridge_setlink = br_setlink, 443 .ndo_bridge_dellink = br_dellink, 444 .ndo_features_check = passthru_features_check, 445 }; 446 447 static struct device_type br_type = { 448 .name = "bridge", 449 }; 450 451 void br_dev_setup(struct net_device *dev) 452 { 453 struct net_bridge *br = netdev_priv(dev); 454 455 eth_hw_addr_random(dev); 456 ether_setup(dev); 457 458 dev->netdev_ops = &br_netdev_ops; 459 dev->needs_free_netdev = true; 460 dev->ethtool_ops = &br_ethtool_ops; 461 SET_NETDEV_DEVTYPE(dev, &br_type); 462 dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE; 463 464 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 465 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; 466 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 467 NETIF_F_HW_VLAN_STAG_TX; 468 dev->vlan_features = COMMON_FEATURES; 469 470 br->dev = dev; 471 spin_lock_init(&br->lock); 472 INIT_LIST_HEAD(&br->port_list); 473 INIT_HLIST_HEAD(&br->fdb_list); 474 #if IS_ENABLED(CONFIG_BRIDGE_MRP) 475 INIT_LIST_HEAD(&br->mrp_list); 476 #endif 477 spin_lock_init(&br->hash_lock); 478 479 br->bridge_id.prio[0] = 0x80; 480 br->bridge_id.prio[1] = 0x00; 481 482 ether_addr_copy(br->group_addr, eth_stp_addr); 483 484 br->stp_enabled = BR_NO_STP; 485 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 486 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; 487 488 br->designated_root = br->bridge_id; 489 br->bridge_max_age = br->max_age = 20 * HZ; 490 br->bridge_hello_time = br->hello_time = 2 * HZ; 491 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 492 br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME; 493 dev->max_mtu = ETH_MAX_MTU; 494 495 br_netfilter_rtable_init(br); 496 br_stp_timer_init(br); 497 br_multicast_init(br); 498 INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup); 499 } 500