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 <asm/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 /* net device transmit always called with BH disabled */ 32 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 33 { 34 struct net_bridge *br = netdev_priv(dev); 35 const unsigned char *dest = skb->data; 36 struct net_bridge_fdb_entry *dst; 37 struct net_bridge_mdb_entry *mdst; 38 struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); 39 const struct nf_br_ops *nf_ops; 40 u16 vid = 0; 41 42 rcu_read_lock(); 43 nf_ops = rcu_dereference(nf_br_ops); 44 if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) { 45 rcu_read_unlock(); 46 return NETDEV_TX_OK; 47 } 48 49 u64_stats_update_begin(&brstats->syncp); 50 brstats->tx_packets++; 51 brstats->tx_bytes += skb->len; 52 u64_stats_update_end(&brstats->syncp); 53 54 BR_INPUT_SKB_CB(skb)->brdev = dev; 55 56 skb_reset_mac_header(skb); 57 skb_pull(skb, ETH_HLEN); 58 59 if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid)) 60 goto out; 61 62 if (is_broadcast_ether_addr(dest)) 63 br_flood_deliver(br, skb, false); 64 else if (is_multicast_ether_addr(dest)) { 65 if (unlikely(netpoll_tx_running(dev))) { 66 br_flood_deliver(br, skb, false); 67 goto out; 68 } 69 if (br_multicast_rcv(br, NULL, skb, vid)) { 70 kfree_skb(skb); 71 goto out; 72 } 73 74 mdst = br_mdb_get(br, skb, vid); 75 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && 76 br_multicast_querier_exists(br, eth_hdr(skb))) 77 br_multicast_deliver(mdst, skb); 78 else 79 br_flood_deliver(br, skb, false); 80 } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL) 81 br_deliver(dst->dst, skb); 82 else 83 br_flood_deliver(br, skb, true); 84 85 out: 86 rcu_read_unlock(); 87 return NETDEV_TX_OK; 88 } 89 90 static int br_dev_init(struct net_device *dev) 91 { 92 struct net_bridge *br = netdev_priv(dev); 93 int err; 94 95 br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 96 if (!br->stats) 97 return -ENOMEM; 98 99 err = br_vlan_init(br); 100 if (err) 101 free_percpu(br->stats); 102 103 return err; 104 } 105 106 static int br_dev_open(struct net_device *dev) 107 { 108 struct net_bridge *br = netdev_priv(dev); 109 110 netdev_update_features(dev); 111 netif_start_queue(dev); 112 br_stp_enable_bridge(br); 113 br_multicast_open(br); 114 115 return 0; 116 } 117 118 static void br_dev_set_multicast_list(struct net_device *dev) 119 { 120 } 121 122 static void br_dev_change_rx_flags(struct net_device *dev, int change) 123 { 124 if (change & IFF_PROMISC) 125 br_manage_promisc(netdev_priv(dev)); 126 } 127 128 static int br_dev_stop(struct net_device *dev) 129 { 130 struct net_bridge *br = netdev_priv(dev); 131 132 br_stp_disable_bridge(br); 133 br_multicast_stop(br); 134 135 netif_stop_queue(dev); 136 137 return 0; 138 } 139 140 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, 141 struct rtnl_link_stats64 *stats) 142 { 143 struct net_bridge *br = netdev_priv(dev); 144 struct pcpu_sw_netstats tmp, sum = { 0 }; 145 unsigned int cpu; 146 147 for_each_possible_cpu(cpu) { 148 unsigned int start; 149 const struct pcpu_sw_netstats *bstats 150 = per_cpu_ptr(br->stats, cpu); 151 do { 152 start = u64_stats_fetch_begin_irq(&bstats->syncp); 153 memcpy(&tmp, bstats, sizeof(tmp)); 154 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start)); 155 sum.tx_bytes += tmp.tx_bytes; 156 sum.tx_packets += tmp.tx_packets; 157 sum.rx_bytes += tmp.rx_bytes; 158 sum.rx_packets += tmp.rx_packets; 159 } 160 161 stats->tx_bytes = sum.tx_bytes; 162 stats->tx_packets = sum.tx_packets; 163 stats->rx_bytes = sum.rx_bytes; 164 stats->rx_packets = sum.rx_packets; 165 166 return stats; 167 } 168 169 static int br_change_mtu(struct net_device *dev, int new_mtu) 170 { 171 struct net_bridge *br = netdev_priv(dev); 172 if (new_mtu < 68 || new_mtu > br_min_mtu(br)) 173 return -EINVAL; 174 175 dev->mtu = new_mtu; 176 177 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 178 /* remember the MTU in the rtable for PMTU */ 179 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 180 #endif 181 182 return 0; 183 } 184 185 /* Allow setting mac address to any valid ethernet address. */ 186 static int br_set_mac_address(struct net_device *dev, void *p) 187 { 188 struct net_bridge *br = netdev_priv(dev); 189 struct sockaddr *addr = p; 190 191 if (!is_valid_ether_addr(addr->sa_data)) 192 return -EADDRNOTAVAIL; 193 194 spin_lock_bh(&br->lock); 195 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 196 /* Mac address will be changed in br_stp_change_bridge_id(). */ 197 br_stp_change_bridge_id(br, addr->sa_data); 198 } 199 spin_unlock_bh(&br->lock); 200 201 return 0; 202 } 203 204 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 205 { 206 strlcpy(info->driver, "bridge", sizeof(info->driver)); 207 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 208 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 209 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 210 } 211 212 static netdev_features_t br_fix_features(struct net_device *dev, 213 netdev_features_t features) 214 { 215 struct net_bridge *br = netdev_priv(dev); 216 217 return br_features_recompute(br, features); 218 } 219 220 #ifdef CONFIG_NET_POLL_CONTROLLER 221 static void br_poll_controller(struct net_device *br_dev) 222 { 223 } 224 225 static void br_netpoll_cleanup(struct net_device *dev) 226 { 227 struct net_bridge *br = netdev_priv(dev); 228 struct net_bridge_port *p; 229 230 list_for_each_entry(p, &br->port_list, list) 231 br_netpoll_disable(p); 232 } 233 234 static int __br_netpoll_enable(struct net_bridge_port *p) 235 { 236 struct netpoll *np; 237 int err; 238 239 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 240 if (!np) 241 return -ENOMEM; 242 243 err = __netpoll_setup(np, p->dev); 244 if (err) { 245 kfree(np); 246 return err; 247 } 248 249 p->np = np; 250 return err; 251 } 252 253 int br_netpoll_enable(struct net_bridge_port *p) 254 { 255 if (!p->br->dev->npinfo) 256 return 0; 257 258 return __br_netpoll_enable(p); 259 } 260 261 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 262 { 263 struct net_bridge *br = netdev_priv(dev); 264 struct net_bridge_port *p; 265 int err = 0; 266 267 list_for_each_entry(p, &br->port_list, list) { 268 if (!p->dev) 269 continue; 270 err = __br_netpoll_enable(p); 271 if (err) 272 goto fail; 273 } 274 275 out: 276 return err; 277 278 fail: 279 br_netpoll_cleanup(dev); 280 goto out; 281 } 282 283 void br_netpoll_disable(struct net_bridge_port *p) 284 { 285 struct netpoll *np = p->np; 286 287 if (!np) 288 return; 289 290 p->np = NULL; 291 292 __netpoll_free_async(np); 293 } 294 295 #endif 296 297 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 298 299 { 300 struct net_bridge *br = netdev_priv(dev); 301 302 return br_add_if(br, slave_dev); 303 } 304 305 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 306 { 307 struct net_bridge *br = netdev_priv(dev); 308 309 return br_del_if(br, slave_dev); 310 } 311 312 static const struct ethtool_ops br_ethtool_ops = { 313 .get_drvinfo = br_getinfo, 314 .get_link = ethtool_op_get_link, 315 }; 316 317 static const struct net_device_ops br_netdev_ops = { 318 .ndo_open = br_dev_open, 319 .ndo_stop = br_dev_stop, 320 .ndo_init = br_dev_init, 321 .ndo_start_xmit = br_dev_xmit, 322 .ndo_get_stats64 = br_get_stats64, 323 .ndo_set_mac_address = br_set_mac_address, 324 .ndo_set_rx_mode = br_dev_set_multicast_list, 325 .ndo_change_rx_flags = br_dev_change_rx_flags, 326 .ndo_change_mtu = br_change_mtu, 327 .ndo_do_ioctl = br_dev_ioctl, 328 #ifdef CONFIG_NET_POLL_CONTROLLER 329 .ndo_netpoll_setup = br_netpoll_setup, 330 .ndo_netpoll_cleanup = br_netpoll_cleanup, 331 .ndo_poll_controller = br_poll_controller, 332 #endif 333 .ndo_add_slave = br_add_slave, 334 .ndo_del_slave = br_del_slave, 335 .ndo_fix_features = br_fix_features, 336 .ndo_fdb_add = br_fdb_add, 337 .ndo_fdb_del = br_fdb_delete, 338 .ndo_fdb_dump = br_fdb_dump, 339 .ndo_bridge_getlink = br_getlink, 340 .ndo_bridge_setlink = br_setlink, 341 .ndo_bridge_dellink = br_dellink, 342 }; 343 344 static void br_dev_free(struct net_device *dev) 345 { 346 struct net_bridge *br = netdev_priv(dev); 347 348 free_percpu(br->stats); 349 free_netdev(dev); 350 } 351 352 static struct device_type br_type = { 353 .name = "bridge", 354 }; 355 356 void br_dev_setup(struct net_device *dev) 357 { 358 struct net_bridge *br = netdev_priv(dev); 359 360 eth_hw_addr_random(dev); 361 ether_setup(dev); 362 363 dev->netdev_ops = &br_netdev_ops; 364 dev->destructor = br_dev_free; 365 dev->ethtool_ops = &br_ethtool_ops; 366 SET_NETDEV_DEVTYPE(dev, &br_type); 367 dev->tx_queue_len = 0; 368 dev->priv_flags = IFF_EBRIDGE; 369 370 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 371 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; 372 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 373 NETIF_F_HW_VLAN_STAG_TX; 374 dev->vlan_features = COMMON_FEATURES; 375 376 br->dev = dev; 377 spin_lock_init(&br->lock); 378 INIT_LIST_HEAD(&br->port_list); 379 spin_lock_init(&br->hash_lock); 380 381 br->bridge_id.prio[0] = 0x80; 382 br->bridge_id.prio[1] = 0x00; 383 384 ether_addr_copy(br->group_addr, eth_reserved_addr_base); 385 386 br->stp_enabled = BR_NO_STP; 387 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 388 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; 389 390 br->designated_root = br->bridge_id; 391 br->bridge_max_age = br->max_age = 20 * HZ; 392 br->bridge_hello_time = br->hello_time = 2 * HZ; 393 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 394 br->ageing_time = 300 * HZ; 395 396 br_netfilter_rtable_init(br); 397 br_stp_timer_init(br); 398 br_multicast_init(br); 399 } 400