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 const unsigned char *dest = skb->data; 38 struct net_bridge_fdb_entry *dst; 39 struct net_bridge_mdb_entry *mdst; 40 struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); 41 const struct nf_br_ops *nf_ops; 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_INPUT_SKB_CB(skb)->brdev = dev; 57 58 skb_reset_mac_header(skb); 59 skb_pull(skb, ETH_HLEN); 60 61 if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid)) 62 goto out; 63 64 if (is_broadcast_ether_addr(dest)) { 65 br_flood(br, skb, BR_PKT_BROADCAST, false, true); 66 } else if (is_multicast_ether_addr(dest)) { 67 if (unlikely(netpoll_tx_running(dev))) { 68 br_flood(br, skb, BR_PKT_MULTICAST, false, true); 69 goto out; 70 } 71 if (br_multicast_rcv(br, NULL, skb, vid)) { 72 kfree_skb(skb); 73 goto out; 74 } 75 76 mdst = br_mdb_get(br, skb, vid); 77 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && 78 br_multicast_querier_exists(br, eth_hdr(skb))) 79 br_multicast_flood(mdst, skb, false, true); 80 else 81 br_flood(br, skb, BR_PKT_MULTICAST, false, true); 82 } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL) { 83 br_forward(dst->dst, skb, false, true); 84 } else { 85 br_flood(br, skb, BR_PKT_UNICAST, false, true); 86 } 87 out: 88 rcu_read_unlock(); 89 return NETDEV_TX_OK; 90 } 91 92 static void br_set_lockdep_class(struct net_device *dev) 93 { 94 lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key); 95 } 96 97 static int br_dev_init(struct net_device *dev) 98 { 99 struct net_bridge *br = netdev_priv(dev); 100 int err; 101 102 br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 103 if (!br->stats) 104 return -ENOMEM; 105 106 err = br_vlan_init(br); 107 if (err) { 108 free_percpu(br->stats); 109 return err; 110 } 111 112 err = br_multicast_init_stats(br); 113 if (err) { 114 free_percpu(br->stats); 115 br_vlan_flush(br); 116 } 117 br_set_lockdep_class(dev); 118 119 return err; 120 } 121 122 static int br_dev_open(struct net_device *dev) 123 { 124 struct net_bridge *br = netdev_priv(dev); 125 126 netdev_update_features(dev); 127 netif_start_queue(dev); 128 br_stp_enable_bridge(br); 129 br_multicast_open(br); 130 131 return 0; 132 } 133 134 static void br_dev_set_multicast_list(struct net_device *dev) 135 { 136 } 137 138 static void br_dev_change_rx_flags(struct net_device *dev, int change) 139 { 140 if (change & IFF_PROMISC) 141 br_manage_promisc(netdev_priv(dev)); 142 } 143 144 static int br_dev_stop(struct net_device *dev) 145 { 146 struct net_bridge *br = netdev_priv(dev); 147 148 br_stp_disable_bridge(br); 149 br_multicast_stop(br); 150 151 netif_stop_queue(dev); 152 153 return 0; 154 } 155 156 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, 157 struct rtnl_link_stats64 *stats) 158 { 159 struct net_bridge *br = netdev_priv(dev); 160 struct pcpu_sw_netstats tmp, sum = { 0 }; 161 unsigned int cpu; 162 163 for_each_possible_cpu(cpu) { 164 unsigned int start; 165 const struct pcpu_sw_netstats *bstats 166 = per_cpu_ptr(br->stats, cpu); 167 do { 168 start = u64_stats_fetch_begin_irq(&bstats->syncp); 169 memcpy(&tmp, bstats, sizeof(tmp)); 170 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start)); 171 sum.tx_bytes += tmp.tx_bytes; 172 sum.tx_packets += tmp.tx_packets; 173 sum.rx_bytes += tmp.rx_bytes; 174 sum.rx_packets += tmp.rx_packets; 175 } 176 177 stats->tx_bytes = sum.tx_bytes; 178 stats->tx_packets = sum.tx_packets; 179 stats->rx_bytes = sum.rx_bytes; 180 stats->rx_packets = sum.rx_packets; 181 182 return stats; 183 } 184 185 static int br_change_mtu(struct net_device *dev, int new_mtu) 186 { 187 struct net_bridge *br = netdev_priv(dev); 188 if (new_mtu > br_min_mtu(br)) 189 return -EINVAL; 190 191 dev->mtu = new_mtu; 192 193 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 194 /* remember the MTU in the rtable for PMTU */ 195 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 196 #endif 197 198 return 0; 199 } 200 201 /* Allow setting mac address to any valid ethernet address. */ 202 static int br_set_mac_address(struct net_device *dev, void *p) 203 { 204 struct net_bridge *br = netdev_priv(dev); 205 struct sockaddr *addr = p; 206 207 if (!is_valid_ether_addr(addr->sa_data)) 208 return -EADDRNOTAVAIL; 209 210 spin_lock_bh(&br->lock); 211 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 212 /* Mac address will be changed in br_stp_change_bridge_id(). */ 213 br_stp_change_bridge_id(br, addr->sa_data); 214 } 215 spin_unlock_bh(&br->lock); 216 217 return 0; 218 } 219 220 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 221 { 222 strlcpy(info->driver, "bridge", sizeof(info->driver)); 223 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 224 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 225 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 226 } 227 228 static netdev_features_t br_fix_features(struct net_device *dev, 229 netdev_features_t features) 230 { 231 struct net_bridge *br = netdev_priv(dev); 232 233 return br_features_recompute(br, features); 234 } 235 236 #ifdef CONFIG_NET_POLL_CONTROLLER 237 static void br_poll_controller(struct net_device *br_dev) 238 { 239 } 240 241 static void br_netpoll_cleanup(struct net_device *dev) 242 { 243 struct net_bridge *br = netdev_priv(dev); 244 struct net_bridge_port *p; 245 246 list_for_each_entry(p, &br->port_list, list) 247 br_netpoll_disable(p); 248 } 249 250 static int __br_netpoll_enable(struct net_bridge_port *p) 251 { 252 struct netpoll *np; 253 int err; 254 255 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 256 if (!np) 257 return -ENOMEM; 258 259 err = __netpoll_setup(np, p->dev); 260 if (err) { 261 kfree(np); 262 return err; 263 } 264 265 p->np = np; 266 return err; 267 } 268 269 int br_netpoll_enable(struct net_bridge_port *p) 270 { 271 if (!p->br->dev->npinfo) 272 return 0; 273 274 return __br_netpoll_enable(p); 275 } 276 277 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 278 { 279 struct net_bridge *br = netdev_priv(dev); 280 struct net_bridge_port *p; 281 int err = 0; 282 283 list_for_each_entry(p, &br->port_list, list) { 284 if (!p->dev) 285 continue; 286 err = __br_netpoll_enable(p); 287 if (err) 288 goto fail; 289 } 290 291 out: 292 return err; 293 294 fail: 295 br_netpoll_cleanup(dev); 296 goto out; 297 } 298 299 void br_netpoll_disable(struct net_bridge_port *p) 300 { 301 struct netpoll *np = p->np; 302 303 if (!np) 304 return; 305 306 p->np = NULL; 307 308 __netpoll_free_async(np); 309 } 310 311 #endif 312 313 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 314 315 { 316 struct net_bridge *br = netdev_priv(dev); 317 318 return br_add_if(br, slave_dev); 319 } 320 321 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 322 { 323 struct net_bridge *br = netdev_priv(dev); 324 325 return br_del_if(br, slave_dev); 326 } 327 328 static const struct ethtool_ops br_ethtool_ops = { 329 .get_drvinfo = br_getinfo, 330 .get_link = ethtool_op_get_link, 331 }; 332 333 static const struct net_device_ops br_netdev_ops = { 334 .ndo_open = br_dev_open, 335 .ndo_stop = br_dev_stop, 336 .ndo_init = br_dev_init, 337 .ndo_start_xmit = br_dev_xmit, 338 .ndo_get_stats64 = br_get_stats64, 339 .ndo_set_mac_address = br_set_mac_address, 340 .ndo_set_rx_mode = br_dev_set_multicast_list, 341 .ndo_change_rx_flags = br_dev_change_rx_flags, 342 .ndo_change_mtu = br_change_mtu, 343 .ndo_do_ioctl = br_dev_ioctl, 344 #ifdef CONFIG_NET_POLL_CONTROLLER 345 .ndo_netpoll_setup = br_netpoll_setup, 346 .ndo_netpoll_cleanup = br_netpoll_cleanup, 347 .ndo_poll_controller = br_poll_controller, 348 #endif 349 .ndo_add_slave = br_add_slave, 350 .ndo_del_slave = br_del_slave, 351 .ndo_fix_features = br_fix_features, 352 .ndo_neigh_construct = netdev_default_l2upper_neigh_construct, 353 .ndo_neigh_destroy = netdev_default_l2upper_neigh_destroy, 354 .ndo_fdb_add = br_fdb_add, 355 .ndo_fdb_del = br_fdb_delete, 356 .ndo_fdb_dump = br_fdb_dump, 357 .ndo_bridge_getlink = br_getlink, 358 .ndo_bridge_setlink = br_setlink, 359 .ndo_bridge_dellink = br_dellink, 360 .ndo_features_check = passthru_features_check, 361 }; 362 363 static void br_dev_free(struct net_device *dev) 364 { 365 struct net_bridge *br = netdev_priv(dev); 366 367 free_percpu(br->stats); 368 free_netdev(dev); 369 } 370 371 static struct device_type br_type = { 372 .name = "bridge", 373 }; 374 375 void br_dev_setup(struct net_device *dev) 376 { 377 struct net_bridge *br = netdev_priv(dev); 378 379 eth_hw_addr_random(dev); 380 ether_setup(dev); 381 382 dev->netdev_ops = &br_netdev_ops; 383 dev->destructor = br_dev_free; 384 dev->ethtool_ops = &br_ethtool_ops; 385 SET_NETDEV_DEVTYPE(dev, &br_type); 386 dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE; 387 388 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 389 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; 390 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 391 NETIF_F_HW_VLAN_STAG_TX; 392 dev->vlan_features = COMMON_FEATURES; 393 394 br->dev = dev; 395 spin_lock_init(&br->lock); 396 INIT_LIST_HEAD(&br->port_list); 397 spin_lock_init(&br->hash_lock); 398 399 br->bridge_id.prio[0] = 0x80; 400 br->bridge_id.prio[1] = 0x00; 401 402 ether_addr_copy(br->group_addr, eth_reserved_addr_base); 403 404 br->stp_enabled = BR_NO_STP; 405 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 406 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; 407 408 br->designated_root = br->bridge_id; 409 br->bridge_max_age = br->max_age = 20 * HZ; 410 br->bridge_hello_time = br->hello_time = 2 * HZ; 411 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 412 br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME; 413 dev->max_mtu = ETH_MAX_MTU; 414 415 br_netfilter_rtable_init(br); 416 br_stp_timer_init(br); 417 br_multicast_init(br); 418 } 419