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