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 /* net device transmit always called with BH disabled */ 29 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 30 { 31 struct net_bridge *br = netdev_priv(dev); 32 const unsigned char *dest = skb->data; 33 struct net_bridge_fdb_entry *dst; 34 struct net_bridge_mdb_entry *mdst; 35 struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); 36 u16 vid = 0; 37 38 rcu_read_lock(); 39 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 40 if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { 41 br_nf_pre_routing_finish_bridge_slow(skb); 42 rcu_read_unlock(); 43 return NETDEV_TX_OK; 44 } 45 #endif 46 47 u64_stats_update_begin(&brstats->syncp); 48 brstats->tx_packets++; 49 brstats->tx_bytes += skb->len; 50 u64_stats_update_end(&brstats->syncp); 51 52 BR_INPUT_SKB_CB(skb)->brdev = dev; 53 54 skb_reset_mac_header(skb); 55 skb_pull(skb, ETH_HLEN); 56 57 if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid)) 58 goto out; 59 60 if (is_broadcast_ether_addr(dest)) 61 br_flood_deliver(br, skb, false); 62 else if (is_multicast_ether_addr(dest)) { 63 if (unlikely(netpoll_tx_running(dev))) { 64 br_flood_deliver(br, skb, false); 65 goto out; 66 } 67 if (br_multicast_rcv(br, NULL, skb, vid)) { 68 kfree_skb(skb); 69 goto out; 70 } 71 72 mdst = br_mdb_get(br, skb, vid); 73 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && 74 br_multicast_querier_exists(br, eth_hdr(skb))) 75 br_multicast_deliver(mdst, skb); 76 else 77 br_flood_deliver(br, skb, false); 78 } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL) 79 br_deliver(dst->dst, skb); 80 else 81 br_flood_deliver(br, skb, true); 82 83 out: 84 rcu_read_unlock(); 85 return NETDEV_TX_OK; 86 } 87 88 static int br_dev_init(struct net_device *dev) 89 { 90 struct net_bridge *br = netdev_priv(dev); 91 int err; 92 93 br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); 94 if (!br->stats) 95 return -ENOMEM; 96 97 err = br_vlan_init(br); 98 if (err) 99 free_percpu(br->stats); 100 101 return err; 102 } 103 104 static int br_dev_open(struct net_device *dev) 105 { 106 struct net_bridge *br = netdev_priv(dev); 107 108 netdev_update_features(dev); 109 netif_start_queue(dev); 110 br_stp_enable_bridge(br); 111 br_multicast_open(br); 112 113 return 0; 114 } 115 116 static void br_dev_set_multicast_list(struct net_device *dev) 117 { 118 } 119 120 static void br_dev_change_rx_flags(struct net_device *dev, int change) 121 { 122 if (change & IFF_PROMISC) 123 br_manage_promisc(netdev_priv(dev)); 124 } 125 126 static int br_dev_stop(struct net_device *dev) 127 { 128 struct net_bridge *br = netdev_priv(dev); 129 130 br_stp_disable_bridge(br); 131 br_multicast_stop(br); 132 133 netif_stop_queue(dev); 134 135 return 0; 136 } 137 138 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, 139 struct rtnl_link_stats64 *stats) 140 { 141 struct net_bridge *br = netdev_priv(dev); 142 struct pcpu_sw_netstats tmp, sum = { 0 }; 143 unsigned int cpu; 144 145 for_each_possible_cpu(cpu) { 146 unsigned int start; 147 const struct pcpu_sw_netstats *bstats 148 = per_cpu_ptr(br->stats, cpu); 149 do { 150 start = u64_stats_fetch_begin_irq(&bstats->syncp); 151 memcpy(&tmp, bstats, sizeof(tmp)); 152 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start)); 153 sum.tx_bytes += tmp.tx_bytes; 154 sum.tx_packets += tmp.tx_packets; 155 sum.rx_bytes += tmp.rx_bytes; 156 sum.rx_packets += tmp.rx_packets; 157 } 158 159 stats->tx_bytes = sum.tx_bytes; 160 stats->tx_packets = sum.tx_packets; 161 stats->rx_bytes = sum.rx_bytes; 162 stats->rx_packets = sum.rx_packets; 163 164 return stats; 165 } 166 167 static int br_change_mtu(struct net_device *dev, int new_mtu) 168 { 169 struct net_bridge *br = netdev_priv(dev); 170 if (new_mtu < 68 || new_mtu > br_min_mtu(br)) 171 return -EINVAL; 172 173 dev->mtu = new_mtu; 174 175 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) 176 /* remember the MTU in the rtable for PMTU */ 177 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 178 #endif 179 180 return 0; 181 } 182 183 /* Allow setting mac address to any valid ethernet address. */ 184 static int br_set_mac_address(struct net_device *dev, void *p) 185 { 186 struct net_bridge *br = netdev_priv(dev); 187 struct sockaddr *addr = p; 188 189 if (!is_valid_ether_addr(addr->sa_data)) 190 return -EADDRNOTAVAIL; 191 192 spin_lock_bh(&br->lock); 193 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 194 /* Mac address will be changed in br_stp_change_bridge_id(). */ 195 br_stp_change_bridge_id(br, addr->sa_data); 196 } 197 spin_unlock_bh(&br->lock); 198 199 return 0; 200 } 201 202 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 203 { 204 strlcpy(info->driver, "bridge", sizeof(info->driver)); 205 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 206 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 207 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 208 } 209 210 static netdev_features_t br_fix_features(struct net_device *dev, 211 netdev_features_t features) 212 { 213 struct net_bridge *br = netdev_priv(dev); 214 215 return br_features_recompute(br, features); 216 } 217 218 #ifdef CONFIG_NET_POLL_CONTROLLER 219 static void br_poll_controller(struct net_device *br_dev) 220 { 221 } 222 223 static void br_netpoll_cleanup(struct net_device *dev) 224 { 225 struct net_bridge *br = netdev_priv(dev); 226 struct net_bridge_port *p; 227 228 list_for_each_entry(p, &br->port_list, list) 229 br_netpoll_disable(p); 230 } 231 232 static int __br_netpoll_enable(struct net_bridge_port *p) 233 { 234 struct netpoll *np; 235 int err; 236 237 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 238 if (!np) 239 return -ENOMEM; 240 241 err = __netpoll_setup(np, p->dev); 242 if (err) { 243 kfree(np); 244 return err; 245 } 246 247 p->np = np; 248 return err; 249 } 250 251 int br_netpoll_enable(struct net_bridge_port *p) 252 { 253 if (!p->br->dev->npinfo) 254 return 0; 255 256 return __br_netpoll_enable(p); 257 } 258 259 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 260 { 261 struct net_bridge *br = netdev_priv(dev); 262 struct net_bridge_port *p; 263 int err = 0; 264 265 list_for_each_entry(p, &br->port_list, list) { 266 if (!p->dev) 267 continue; 268 err = __br_netpoll_enable(p); 269 if (err) 270 goto fail; 271 } 272 273 out: 274 return err; 275 276 fail: 277 br_netpoll_cleanup(dev); 278 goto out; 279 } 280 281 void br_netpoll_disable(struct net_bridge_port *p) 282 { 283 struct netpoll *np = p->np; 284 285 if (!np) 286 return; 287 288 p->np = NULL; 289 290 __netpoll_free_async(np); 291 } 292 293 #endif 294 295 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 296 297 { 298 struct net_bridge *br = netdev_priv(dev); 299 300 return br_add_if(br, slave_dev); 301 } 302 303 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 304 { 305 struct net_bridge *br = netdev_priv(dev); 306 307 return br_del_if(br, slave_dev); 308 } 309 310 static const struct ethtool_ops br_ethtool_ops = { 311 .get_drvinfo = br_getinfo, 312 .get_link = ethtool_op_get_link, 313 }; 314 315 static const struct net_device_ops br_netdev_ops = { 316 .ndo_open = br_dev_open, 317 .ndo_stop = br_dev_stop, 318 .ndo_init = br_dev_init, 319 .ndo_start_xmit = br_dev_xmit, 320 .ndo_get_stats64 = br_get_stats64, 321 .ndo_set_mac_address = br_set_mac_address, 322 .ndo_set_rx_mode = br_dev_set_multicast_list, 323 .ndo_change_rx_flags = br_dev_change_rx_flags, 324 .ndo_change_mtu = br_change_mtu, 325 .ndo_do_ioctl = br_dev_ioctl, 326 #ifdef CONFIG_NET_POLL_CONTROLLER 327 .ndo_netpoll_setup = br_netpoll_setup, 328 .ndo_netpoll_cleanup = br_netpoll_cleanup, 329 .ndo_poll_controller = br_poll_controller, 330 #endif 331 .ndo_add_slave = br_add_slave, 332 .ndo_del_slave = br_del_slave, 333 .ndo_fix_features = br_fix_features, 334 .ndo_fdb_add = br_fdb_add, 335 .ndo_fdb_del = br_fdb_delete, 336 .ndo_fdb_dump = br_fdb_dump, 337 .ndo_bridge_getlink = br_getlink, 338 .ndo_bridge_setlink = br_setlink, 339 .ndo_bridge_dellink = br_dellink, 340 }; 341 342 static void br_dev_free(struct net_device *dev) 343 { 344 struct net_bridge *br = netdev_priv(dev); 345 346 free_percpu(br->stats); 347 free_netdev(dev); 348 } 349 350 static struct device_type br_type = { 351 .name = "bridge", 352 }; 353 354 void br_dev_setup(struct net_device *dev) 355 { 356 struct net_bridge *br = netdev_priv(dev); 357 358 eth_hw_addr_random(dev); 359 ether_setup(dev); 360 361 dev->netdev_ops = &br_netdev_ops; 362 dev->destructor = br_dev_free; 363 dev->ethtool_ops = &br_ethtool_ops; 364 SET_NETDEV_DEVTYPE(dev, &br_type); 365 dev->tx_queue_len = 0; 366 dev->priv_flags = IFF_EBRIDGE; 367 368 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 369 NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; 370 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | 371 NETIF_F_HW_VLAN_STAG_TX; 372 dev->vlan_features = COMMON_FEATURES; 373 374 br->dev = dev; 375 spin_lock_init(&br->lock); 376 INIT_LIST_HEAD(&br->port_list); 377 spin_lock_init(&br->hash_lock); 378 379 br->bridge_id.prio[0] = 0x80; 380 br->bridge_id.prio[1] = 0x00; 381 382 ether_addr_copy(br->group_addr, eth_reserved_addr_base); 383 384 br->stp_enabled = BR_NO_STP; 385 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 386 br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; 387 388 br->designated_root = br->bridge_id; 389 br->bridge_max_age = br->max_age = 20 * HZ; 390 br->bridge_hello_time = br->hello_time = 2 * HZ; 391 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 392 br->ageing_time = 300 * HZ; 393 394 br_netfilter_rtable_init(br); 395 br_stp_timer_init(br); 396 br_multicast_init(br); 397 } 398