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