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