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