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