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); 209 210 dev_fetch_sw_netstats(stats, br->stats); 211 } 212 213 static int br_change_mtu(struct net_device *dev, int new_mtu) 214 { 215 struct net_bridge *br = netdev_priv(dev); 216 217 dev->mtu = new_mtu; 218 219 /* this flag will be cleared if the MTU was automatically adjusted */ 220 br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true); 221 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 222 /* remember the MTU in the rtable for PMTU */ 223 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 224 #endif 225 226 return 0; 227 } 228 229 /* Allow setting mac address to any valid ethernet address. */ 230 static int br_set_mac_address(struct net_device *dev, void *p) 231 { 232 struct net_bridge *br = netdev_priv(dev); 233 struct sockaddr *addr = p; 234 235 if (!is_valid_ether_addr(addr->sa_data)) 236 return -EADDRNOTAVAIL; 237 238 /* dev_set_mac_addr() can be called by a master device on bridge's 239 * NETDEV_UNREGISTER, but since it's being destroyed do nothing 240 */ 241 if (dev->reg_state != NETREG_REGISTERED) 242 return -EBUSY; 243 244 spin_lock_bh(&br->lock); 245 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 246 /* Mac address will be changed in br_stp_change_bridge_id(). */ 247 br_stp_change_bridge_id(br, addr->sa_data); 248 } 249 spin_unlock_bh(&br->lock); 250 251 return 0; 252 } 253 254 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 255 { 256 strlcpy(info->driver, "bridge", sizeof(info->driver)); 257 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 258 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 259 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 260 } 261 262 static int br_get_link_ksettings(struct net_device *dev, 263 struct ethtool_link_ksettings *cmd) 264 { 265 struct net_bridge *br = netdev_priv(dev); 266 struct net_bridge_port *p; 267 268 cmd->base.duplex = DUPLEX_UNKNOWN; 269 cmd->base.port = PORT_OTHER; 270 cmd->base.speed = SPEED_UNKNOWN; 271 272 list_for_each_entry(p, &br->port_list, list) { 273 struct ethtool_link_ksettings ecmd; 274 struct net_device *pdev = p->dev; 275 276 if (!netif_running(pdev) || !netif_oper_up(pdev)) 277 continue; 278 279 if (__ethtool_get_link_ksettings(pdev, &ecmd)) 280 continue; 281 282 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN) 283 continue; 284 285 if (cmd->base.speed == (__u32)SPEED_UNKNOWN || 286 cmd->base.speed < ecmd.base.speed) 287 cmd->base.speed = ecmd.base.speed; 288 } 289 290 return 0; 291 } 292 293 static netdev_features_t br_fix_features(struct net_device *dev, 294 netdev_features_t features) 295 { 296 struct net_bridge *br = netdev_priv(dev); 297 298 return br_features_recompute(br, features); 299 } 300 301 #ifdef CONFIG_NET_POLL_CONTROLLER 302 static void br_poll_controller(struct net_device *br_dev) 303 { 304 } 305 306 static void br_netpoll_cleanup(struct net_device *dev) 307 { 308 struct net_bridge *br = netdev_priv(dev); 309 struct net_bridge_port *p; 310 311 list_for_each_entry(p, &br->port_list, list) 312 br_netpoll_disable(p); 313 } 314 315 static int __br_netpoll_enable(struct net_bridge_port *p) 316 { 317 struct netpoll *np; 318 int err; 319 320 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 321 if (!np) 322 return -ENOMEM; 323 324 err = __netpoll_setup(np, p->dev); 325 if (err) { 326 kfree(np); 327 return err; 328 } 329 330 p->np = np; 331 return err; 332 } 333 334 int br_netpoll_enable(struct net_bridge_port *p) 335 { 336 if (!p->br->dev->npinfo) 337 return 0; 338 339 return __br_netpoll_enable(p); 340 } 341 342 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 343 { 344 struct net_bridge *br = netdev_priv(dev); 345 struct net_bridge_port *p; 346 int err = 0; 347 348 list_for_each_entry(p, &br->port_list, list) { 349 if (!p->dev) 350 continue; 351 err = __br_netpoll_enable(p); 352 if (err) 353 goto fail; 354 } 355 356 out: 357 return err; 358 359 fail: 360 br_netpoll_cleanup(dev); 361 goto out; 362 } 363 364 void br_netpoll_disable(struct net_bridge_port *p) 365 { 366 struct netpoll *np = p->np; 367 368 if (!np) 369 return; 370 371 p->np = NULL; 372 373 __netpoll_free(np); 374 } 375 376 #endif 377 378 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev, 379 struct netlink_ext_ack *extack) 380 381 { 382 struct net_bridge *br = netdev_priv(dev); 383 384 return br_add_if(br, slave_dev, extack); 385 } 386 387 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 388 { 389 struct net_bridge *br = netdev_priv(dev); 390 391 return br_del_if(br, slave_dev); 392 } 393 394 static const struct ethtool_ops br_ethtool_ops = { 395 .get_drvinfo = br_getinfo, 396 .get_link = ethtool_op_get_link, 397 .get_link_ksettings = br_get_link_ksettings, 398 }; 399 400 static const struct net_device_ops br_netdev_ops = { 401 .ndo_open = br_dev_open, 402 .ndo_stop = br_dev_stop, 403 .ndo_init = br_dev_init, 404 .ndo_uninit = br_dev_uninit, 405 .ndo_start_xmit = br_dev_xmit, 406 .ndo_get_stats64 = br_get_stats64, 407 .ndo_set_mac_address = br_set_mac_address, 408 .ndo_set_rx_mode = br_dev_set_multicast_list, 409 .ndo_change_rx_flags = br_dev_change_rx_flags, 410 .ndo_change_mtu = br_change_mtu, 411 .ndo_do_ioctl = br_dev_ioctl, 412 #ifdef CONFIG_NET_POLL_CONTROLLER 413 .ndo_netpoll_setup = br_netpoll_setup, 414 .ndo_netpoll_cleanup = br_netpoll_cleanup, 415 .ndo_poll_controller = br_poll_controller, 416 #endif 417 .ndo_add_slave = br_add_slave, 418 .ndo_del_slave = br_del_slave, 419 .ndo_fix_features = br_fix_features, 420 .ndo_fdb_add = br_fdb_add, 421 .ndo_fdb_del = br_fdb_delete, 422 .ndo_fdb_dump = br_fdb_dump, 423 .ndo_fdb_get = br_fdb_get, 424 .ndo_bridge_getlink = br_getlink, 425 .ndo_bridge_setlink = br_setlink, 426 .ndo_bridge_dellink = br_dellink, 427 .ndo_features_check = passthru_features_check, 428 }; 429 430 static struct device_type br_type = { 431 .name = "bridge", 432 }; 433 434 void br_dev_setup(struct net_device *dev) 435 { 436 struct net_bridge *br = netdev_priv(dev); 437 438 eth_hw_addr_random(dev); 439 ether_setup(dev); 440 441 dev->netdev_ops = &br_netdev_ops; 442 dev->needs_free_netdev = true; 443 dev->ethtool_ops = &br_ethtool_ops; 444 SET_NETDEV_DEVTYPE(dev, &br_type); 445 dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE; 446 447 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 448 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; 449 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 450 NETIF_F_HW_VLAN_STAG_TX; 451 dev->vlan_features = COMMON_FEATURES; 452 453 br->dev = dev; 454 spin_lock_init(&br->lock); 455 INIT_LIST_HEAD(&br->port_list); 456 INIT_HLIST_HEAD(&br->fdb_list); 457 #if IS_ENABLED(CONFIG_BRIDGE_MRP) 458 INIT_LIST_HEAD(&br->mrp_list); 459 #endif 460 spin_lock_init(&br->hash_lock); 461 462 br->bridge_id.prio[0] = 0x80; 463 br->bridge_id.prio[1] = 0x00; 464 465 ether_addr_copy(br->group_addr, eth_stp_addr); 466 467 br->stp_enabled = BR_NO_STP; 468 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 469 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; 470 471 br->designated_root = br->bridge_id; 472 br->bridge_max_age = br->max_age = 20 * HZ; 473 br->bridge_hello_time = br->hello_time = 2 * HZ; 474 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 475 br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME; 476 dev->max_mtu = ETH_MAX_MTU; 477 478 br_netfilter_rtable_init(br); 479 br_stp_timer_init(br); 480 br_multicast_init(br); 481 INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup); 482 } 483