1 /* 2 * Device handling code 3 * Linux ethernet bridge 4 * 5 * Authors: 6 * Lennert Buytenhek <buytenh@gnu.org> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/netdevice.h> 16 #include <linux/netpoll.h> 17 #include <linux/etherdevice.h> 18 #include <linux/ethtool.h> 19 #include <linux/list.h> 20 #include <linux/netfilter_bridge.h> 21 22 #include <linux/uaccess.h> 23 #include "br_private.h" 24 25 #define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \ 26 NETIF_F_GSO_MASK | NETIF_F_HW_CSUM) 27 28 const struct nf_br_ops __rcu *nf_br_ops __read_mostly; 29 EXPORT_SYMBOL_GPL(nf_br_ops); 30 31 static struct lock_class_key bridge_netdev_addr_lock_key; 32 33 /* net device transmit always called with BH disabled */ 34 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 35 { 36 struct net_bridge *br = netdev_priv(dev); 37 struct net_bridge_fdb_entry *dst; 38 struct net_bridge_mdb_entry *mdst; 39 struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); 40 const struct nf_br_ops *nf_ops; 41 const unsigned char *dest; 42 struct ethhdr *eth; 43 u16 vid = 0; 44 45 rcu_read_lock(); 46 nf_ops = rcu_dereference(nf_br_ops); 47 if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) { 48 rcu_read_unlock(); 49 return NETDEV_TX_OK; 50 } 51 52 u64_stats_update_begin(&brstats->syncp); 53 brstats->tx_packets++; 54 brstats->tx_bytes += skb->len; 55 u64_stats_update_end(&brstats->syncp); 56 57 br_switchdev_frame_unmark(skb); 58 BR_INPUT_SKB_CB(skb)->brdev = dev; 59 60 skb_reset_mac_header(skb); 61 eth = eth_hdr(skb); 62 skb_pull(skb, ETH_HLEN); 63 64 if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid)) 65 goto out; 66 67 if (IS_ENABLED(CONFIG_INET) && 68 (eth->h_proto == htons(ETH_P_ARP) || 69 eth->h_proto == htons(ETH_P_RARP)) && 70 br->neigh_suppress_enabled) { 71 br_do_proxy_suppress_arp(skb, br, vid, NULL); 72 } else if (IS_ENABLED(CONFIG_IPV6) && 73 skb->protocol == htons(ETH_P_IPV6) && 74 br->neigh_suppress_enabled && 75 pskb_may_pull(skb, sizeof(struct ipv6hdr) + 76 sizeof(struct nd_msg)) && 77 ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) { 78 struct nd_msg *msg, _msg; 79 80 msg = br_is_nd_neigh_msg(skb, &_msg); 81 if (msg) 82 br_do_suppress_nd(skb, br, vid, NULL, msg); 83 } 84 85 dest = eth_hdr(skb)->h_dest; 86 if (is_broadcast_ether_addr(dest)) { 87 br_flood(br, skb, BR_PKT_BROADCAST, false, true); 88 } else if (is_multicast_ether_addr(dest)) { 89 if (unlikely(netpoll_tx_running(dev))) { 90 br_flood(br, skb, BR_PKT_MULTICAST, false, true); 91 goto out; 92 } 93 if (br_multicast_rcv(br, NULL, skb, vid)) { 94 kfree_skb(skb); 95 goto out; 96 } 97 98 mdst = br_mdb_get(br, skb, vid); 99 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && 100 br_multicast_querier_exists(br, eth_hdr(skb))) 101 br_multicast_flood(mdst, skb, false, true); 102 else 103 br_flood(br, skb, BR_PKT_MULTICAST, false, true); 104 } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) { 105 br_forward(dst->dst, skb, false, true); 106 } else { 107 br_flood(br, skb, BR_PKT_UNICAST, false, true); 108 } 109 out: 110 rcu_read_unlock(); 111 return NETDEV_TX_OK; 112 } 113 114 static void br_set_lockdep_class(struct net_device *dev) 115 { 116 lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key); 117 } 118 119 static int br_dev_init(struct net_device *dev) 120 { 121 struct net_bridge *br = netdev_priv(dev); 122 int err; 123 124 br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 125 if (!br->stats) 126 return -ENOMEM; 127 128 err = br_vlan_init(br); 129 if (err) { 130 free_percpu(br->stats); 131 return err; 132 } 133 134 err = br_multicast_init_stats(br); 135 if (err) { 136 free_percpu(br->stats); 137 br_vlan_flush(br); 138 } 139 br_set_lockdep_class(dev); 140 141 return err; 142 } 143 144 static void br_dev_uninit(struct net_device *dev) 145 { 146 struct net_bridge *br = netdev_priv(dev); 147 148 br_multicast_dev_del(br); 149 br_multicast_uninit_stats(br); 150 br_vlan_flush(br); 151 free_percpu(br->stats); 152 } 153 154 static int br_dev_open(struct net_device *dev) 155 { 156 struct net_bridge *br = netdev_priv(dev); 157 158 netdev_update_features(dev); 159 netif_start_queue(dev); 160 br_stp_enable_bridge(br); 161 br_multicast_open(br); 162 163 return 0; 164 } 165 166 static void br_dev_set_multicast_list(struct net_device *dev) 167 { 168 } 169 170 static void br_dev_change_rx_flags(struct net_device *dev, int change) 171 { 172 if (change & IFF_PROMISC) 173 br_manage_promisc(netdev_priv(dev)); 174 } 175 176 static int br_dev_stop(struct net_device *dev) 177 { 178 struct net_bridge *br = netdev_priv(dev); 179 180 br_stp_disable_bridge(br); 181 br_multicast_stop(br); 182 183 netif_stop_queue(dev); 184 185 return 0; 186 } 187 188 static void br_get_stats64(struct net_device *dev, 189 struct rtnl_link_stats64 *stats) 190 { 191 struct net_bridge *br = netdev_priv(dev); 192 struct pcpu_sw_netstats tmp, sum = { 0 }; 193 unsigned int cpu; 194 195 for_each_possible_cpu(cpu) { 196 unsigned int start; 197 const struct pcpu_sw_netstats *bstats 198 = per_cpu_ptr(br->stats, cpu); 199 do { 200 start = u64_stats_fetch_begin_irq(&bstats->syncp); 201 memcpy(&tmp, bstats, sizeof(tmp)); 202 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start)); 203 sum.tx_bytes += tmp.tx_bytes; 204 sum.tx_packets += tmp.tx_packets; 205 sum.rx_bytes += tmp.rx_bytes; 206 sum.rx_packets += tmp.rx_packets; 207 } 208 209 stats->tx_bytes = sum.tx_bytes; 210 stats->tx_packets = sum.tx_packets; 211 stats->rx_bytes = sum.rx_bytes; 212 stats->rx_packets = sum.rx_packets; 213 } 214 215 static int br_change_mtu(struct net_device *dev, int new_mtu) 216 { 217 struct net_bridge *br = netdev_priv(dev); 218 if (new_mtu > br_min_mtu(br)) 219 return -EINVAL; 220 221 dev->mtu = new_mtu; 222 223 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 224 /* remember the MTU in the rtable for PMTU */ 225 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 226 #endif 227 228 return 0; 229 } 230 231 /* Allow setting mac address to any valid ethernet address. */ 232 static int br_set_mac_address(struct net_device *dev, void *p) 233 { 234 struct net_bridge *br = netdev_priv(dev); 235 struct sockaddr *addr = p; 236 237 if (!is_valid_ether_addr(addr->sa_data)) 238 return -EADDRNOTAVAIL; 239 240 spin_lock_bh(&br->lock); 241 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 242 /* Mac address will be changed in br_stp_change_bridge_id(). */ 243 br_stp_change_bridge_id(br, addr->sa_data); 244 } 245 spin_unlock_bh(&br->lock); 246 247 return 0; 248 } 249 250 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 251 { 252 strlcpy(info->driver, "bridge", sizeof(info->driver)); 253 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 254 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 255 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 256 } 257 258 static netdev_features_t br_fix_features(struct net_device *dev, 259 netdev_features_t features) 260 { 261 struct net_bridge *br = netdev_priv(dev); 262 263 return br_features_recompute(br, features); 264 } 265 266 #ifdef CONFIG_NET_POLL_CONTROLLER 267 static void br_poll_controller(struct net_device *br_dev) 268 { 269 } 270 271 static void br_netpoll_cleanup(struct net_device *dev) 272 { 273 struct net_bridge *br = netdev_priv(dev); 274 struct net_bridge_port *p; 275 276 list_for_each_entry(p, &br->port_list, list) 277 br_netpoll_disable(p); 278 } 279 280 static int __br_netpoll_enable(struct net_bridge_port *p) 281 { 282 struct netpoll *np; 283 int err; 284 285 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 286 if (!np) 287 return -ENOMEM; 288 289 err = __netpoll_setup(np, p->dev); 290 if (err) { 291 kfree(np); 292 return err; 293 } 294 295 p->np = np; 296 return err; 297 } 298 299 int br_netpoll_enable(struct net_bridge_port *p) 300 { 301 if (!p->br->dev->npinfo) 302 return 0; 303 304 return __br_netpoll_enable(p); 305 } 306 307 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 308 { 309 struct net_bridge *br = netdev_priv(dev); 310 struct net_bridge_port *p; 311 int err = 0; 312 313 list_for_each_entry(p, &br->port_list, list) { 314 if (!p->dev) 315 continue; 316 err = __br_netpoll_enable(p); 317 if (err) 318 goto fail; 319 } 320 321 out: 322 return err; 323 324 fail: 325 br_netpoll_cleanup(dev); 326 goto out; 327 } 328 329 void br_netpoll_disable(struct net_bridge_port *p) 330 { 331 struct netpoll *np = p->np; 332 333 if (!np) 334 return; 335 336 p->np = NULL; 337 338 __netpoll_free_async(np); 339 } 340 341 #endif 342 343 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev, 344 struct netlink_ext_ack *extack) 345 346 { 347 struct net_bridge *br = netdev_priv(dev); 348 349 return br_add_if(br, slave_dev, extack); 350 } 351 352 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 353 { 354 struct net_bridge *br = netdev_priv(dev); 355 356 return br_del_if(br, slave_dev); 357 } 358 359 static const struct ethtool_ops br_ethtool_ops = { 360 .get_drvinfo = br_getinfo, 361 .get_link = ethtool_op_get_link, 362 }; 363 364 static const struct net_device_ops br_netdev_ops = { 365 .ndo_open = br_dev_open, 366 .ndo_stop = br_dev_stop, 367 .ndo_init = br_dev_init, 368 .ndo_uninit = br_dev_uninit, 369 .ndo_start_xmit = br_dev_xmit, 370 .ndo_get_stats64 = br_get_stats64, 371 .ndo_set_mac_address = br_set_mac_address, 372 .ndo_set_rx_mode = br_dev_set_multicast_list, 373 .ndo_change_rx_flags = br_dev_change_rx_flags, 374 .ndo_change_mtu = br_change_mtu, 375 .ndo_do_ioctl = br_dev_ioctl, 376 #ifdef CONFIG_NET_POLL_CONTROLLER 377 .ndo_netpoll_setup = br_netpoll_setup, 378 .ndo_netpoll_cleanup = br_netpoll_cleanup, 379 .ndo_poll_controller = br_poll_controller, 380 #endif 381 .ndo_add_slave = br_add_slave, 382 .ndo_del_slave = br_del_slave, 383 .ndo_fix_features = br_fix_features, 384 .ndo_fdb_add = br_fdb_add, 385 .ndo_fdb_del = br_fdb_delete, 386 .ndo_fdb_dump = br_fdb_dump, 387 .ndo_bridge_getlink = br_getlink, 388 .ndo_bridge_setlink = br_setlink, 389 .ndo_bridge_dellink = br_dellink, 390 .ndo_features_check = passthru_features_check, 391 }; 392 393 static struct device_type br_type = { 394 .name = "bridge", 395 }; 396 397 void br_dev_setup(struct net_device *dev) 398 { 399 struct net_bridge *br = netdev_priv(dev); 400 401 eth_hw_addr_random(dev); 402 ether_setup(dev); 403 404 dev->netdev_ops = &br_netdev_ops; 405 dev->needs_free_netdev = true; 406 dev->ethtool_ops = &br_ethtool_ops; 407 SET_NETDEV_DEVTYPE(dev, &br_type); 408 dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE; 409 410 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 411 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; 412 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 413 NETIF_F_HW_VLAN_STAG_TX; 414 dev->vlan_features = COMMON_FEATURES; 415 416 br->dev = dev; 417 spin_lock_init(&br->lock); 418 INIT_LIST_HEAD(&br->port_list); 419 spin_lock_init(&br->hash_lock); 420 421 br->bridge_id.prio[0] = 0x80; 422 br->bridge_id.prio[1] = 0x00; 423 424 ether_addr_copy(br->group_addr, eth_stp_addr); 425 426 br->stp_enabled = BR_NO_STP; 427 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 428 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; 429 430 br->designated_root = br->bridge_id; 431 br->bridge_max_age = br->max_age = 20 * HZ; 432 br->bridge_hello_time = br->hello_time = 2 * HZ; 433 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 434 br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME; 435 dev->max_mtu = ETH_MAX_MTU; 436 437 br_netfilter_rtable_init(br); 438 br_stp_timer_init(br); 439 br_multicast_init(br); 440 INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup); 441 } 442