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