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 /* net device transmit always called with BH disabled */ 26 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 27 { 28 struct net_bridge *br = netdev_priv(dev); 29 const unsigned char *dest = skb->data; 30 struct net_bridge_fdb_entry *dst; 31 struct net_bridge_mdb_entry *mdst; 32 struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats); 33 34 #ifdef CONFIG_BRIDGE_NETFILTER 35 if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { 36 br_nf_pre_routing_finish_bridge_slow(skb); 37 return NETDEV_TX_OK; 38 } 39 #endif 40 41 u64_stats_update_begin(&brstats->syncp); 42 brstats->tx_packets++; 43 brstats->tx_bytes += skb->len; 44 u64_stats_update_end(&brstats->syncp); 45 46 BR_INPUT_SKB_CB(skb)->brdev = dev; 47 48 skb_reset_mac_header(skb); 49 skb_pull(skb, ETH_HLEN); 50 51 rcu_read_lock(); 52 if (is_broadcast_ether_addr(dest)) 53 br_flood_deliver(br, skb); 54 else if (is_multicast_ether_addr(dest)) { 55 if (unlikely(netpoll_tx_running(dev))) { 56 br_flood_deliver(br, skb); 57 goto out; 58 } 59 if (br_multicast_rcv(br, NULL, skb)) { 60 kfree_skb(skb); 61 goto out; 62 } 63 64 mdst = br_mdb_get(br, skb); 65 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) 66 br_multicast_deliver(mdst, skb); 67 else 68 br_flood_deliver(br, skb); 69 } else if ((dst = __br_fdb_get(br, dest)) != NULL) 70 br_deliver(dst->dst, skb); 71 else 72 br_flood_deliver(br, skb); 73 74 out: 75 rcu_read_unlock(); 76 return NETDEV_TX_OK; 77 } 78 79 static int br_dev_init(struct net_device *dev) 80 { 81 struct net_bridge *br = netdev_priv(dev); 82 83 br->stats = alloc_percpu(struct br_cpu_netstats); 84 if (!br->stats) 85 return -ENOMEM; 86 87 return 0; 88 } 89 90 static int br_dev_open(struct net_device *dev) 91 { 92 struct net_bridge *br = netdev_priv(dev); 93 94 netdev_update_features(dev); 95 netif_start_queue(dev); 96 br_stp_enable_bridge(br); 97 br_multicast_open(br); 98 99 return 0; 100 } 101 102 static void br_dev_set_multicast_list(struct net_device *dev) 103 { 104 } 105 106 static int br_dev_stop(struct net_device *dev) 107 { 108 struct net_bridge *br = netdev_priv(dev); 109 110 br_stp_disable_bridge(br); 111 br_multicast_stop(br); 112 113 netif_stop_queue(dev); 114 115 return 0; 116 } 117 118 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, 119 struct rtnl_link_stats64 *stats) 120 { 121 struct net_bridge *br = netdev_priv(dev); 122 struct br_cpu_netstats tmp, sum = { 0 }; 123 unsigned int cpu; 124 125 for_each_possible_cpu(cpu) { 126 unsigned int start; 127 const struct br_cpu_netstats *bstats 128 = per_cpu_ptr(br->stats, cpu); 129 do { 130 start = u64_stats_fetch_begin(&bstats->syncp); 131 memcpy(&tmp, bstats, sizeof(tmp)); 132 } while (u64_stats_fetch_retry(&bstats->syncp, start)); 133 sum.tx_bytes += tmp.tx_bytes; 134 sum.tx_packets += tmp.tx_packets; 135 sum.rx_bytes += tmp.rx_bytes; 136 sum.rx_packets += tmp.rx_packets; 137 } 138 139 stats->tx_bytes = sum.tx_bytes; 140 stats->tx_packets = sum.tx_packets; 141 stats->rx_bytes = sum.rx_bytes; 142 stats->rx_packets = sum.rx_packets; 143 144 return stats; 145 } 146 147 static int br_change_mtu(struct net_device *dev, int new_mtu) 148 { 149 struct net_bridge *br = netdev_priv(dev); 150 if (new_mtu < 68 || new_mtu > br_min_mtu(br)) 151 return -EINVAL; 152 153 dev->mtu = new_mtu; 154 155 #ifdef CONFIG_BRIDGE_NETFILTER 156 /* remember the MTU in the rtable for PMTU */ 157 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 158 #endif 159 160 return 0; 161 } 162 163 /* Allow setting mac address to any valid ethernet address. */ 164 static int br_set_mac_address(struct net_device *dev, void *p) 165 { 166 struct net_bridge *br = netdev_priv(dev); 167 struct sockaddr *addr = p; 168 169 if (!is_valid_ether_addr(addr->sa_data)) 170 return -EADDRNOTAVAIL; 171 172 spin_lock_bh(&br->lock); 173 if (compare_ether_addr(dev->dev_addr, addr->sa_data)) { 174 dev->addr_assign_type &= ~NET_ADDR_RANDOM; 175 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); 176 br_fdb_change_mac_address(br, addr->sa_data); 177 br_stp_change_bridge_id(br, addr->sa_data); 178 } 179 br->flags |= BR_SET_MAC_ADDR; 180 spin_unlock_bh(&br->lock); 181 182 return 0; 183 } 184 185 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 186 { 187 strcpy(info->driver, "bridge"); 188 strcpy(info->version, BR_VERSION); 189 strcpy(info->fw_version, "N/A"); 190 strcpy(info->bus_info, "N/A"); 191 } 192 193 static netdev_features_t br_fix_features(struct net_device *dev, 194 netdev_features_t features) 195 { 196 struct net_bridge *br = netdev_priv(dev); 197 198 return br_features_recompute(br, features); 199 } 200 201 #ifdef CONFIG_NET_POLL_CONTROLLER 202 static void br_poll_controller(struct net_device *br_dev) 203 { 204 } 205 206 static void br_netpoll_cleanup(struct net_device *dev) 207 { 208 struct net_bridge *br = netdev_priv(dev); 209 struct net_bridge_port *p, *n; 210 211 list_for_each_entry_safe(p, n, &br->port_list, list) { 212 br_netpoll_disable(p); 213 } 214 } 215 216 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 217 { 218 struct net_bridge *br = netdev_priv(dev); 219 struct net_bridge_port *p, *n; 220 int err = 0; 221 222 list_for_each_entry_safe(p, n, &br->port_list, list) { 223 if (!p->dev) 224 continue; 225 226 err = br_netpoll_enable(p); 227 if (err) 228 goto fail; 229 } 230 231 out: 232 return err; 233 234 fail: 235 br_netpoll_cleanup(dev); 236 goto out; 237 } 238 239 int br_netpoll_enable(struct net_bridge_port *p) 240 { 241 struct netpoll *np; 242 int err = 0; 243 244 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 245 err = -ENOMEM; 246 if (!np) 247 goto out; 248 249 np->dev = p->dev; 250 strlcpy(np->dev_name, p->dev->name, IFNAMSIZ); 251 252 err = __netpoll_setup(np); 253 if (err) { 254 kfree(np); 255 goto out; 256 } 257 258 p->np = np; 259 260 out: 261 return err; 262 } 263 264 void br_netpoll_disable(struct net_bridge_port *p) 265 { 266 struct netpoll *np = p->np; 267 268 if (!np) 269 return; 270 271 p->np = NULL; 272 273 /* Wait for transmitting packets to finish before freeing. */ 274 synchronize_rcu_bh(); 275 276 __netpoll_cleanup(np); 277 kfree(np); 278 } 279 280 #endif 281 282 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 283 284 { 285 struct net_bridge *br = netdev_priv(dev); 286 287 return br_add_if(br, slave_dev); 288 } 289 290 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 291 { 292 struct net_bridge *br = netdev_priv(dev); 293 294 return br_del_if(br, slave_dev); 295 } 296 297 static const struct ethtool_ops br_ethtool_ops = { 298 .get_drvinfo = br_getinfo, 299 .get_link = ethtool_op_get_link, 300 }; 301 302 static const struct net_device_ops br_netdev_ops = { 303 .ndo_open = br_dev_open, 304 .ndo_stop = br_dev_stop, 305 .ndo_init = br_dev_init, 306 .ndo_start_xmit = br_dev_xmit, 307 .ndo_get_stats64 = br_get_stats64, 308 .ndo_set_mac_address = br_set_mac_address, 309 .ndo_set_rx_mode = br_dev_set_multicast_list, 310 .ndo_change_mtu = br_change_mtu, 311 .ndo_do_ioctl = br_dev_ioctl, 312 #ifdef CONFIG_NET_POLL_CONTROLLER 313 .ndo_netpoll_setup = br_netpoll_setup, 314 .ndo_netpoll_cleanup = br_netpoll_cleanup, 315 .ndo_poll_controller = br_poll_controller, 316 #endif 317 .ndo_add_slave = br_add_slave, 318 .ndo_del_slave = br_del_slave, 319 .ndo_fix_features = br_fix_features, 320 }; 321 322 static void br_dev_free(struct net_device *dev) 323 { 324 struct net_bridge *br = netdev_priv(dev); 325 326 free_percpu(br->stats); 327 free_netdev(dev); 328 } 329 330 static struct device_type br_type = { 331 .name = "bridge", 332 }; 333 334 void br_dev_setup(struct net_device *dev) 335 { 336 struct net_bridge *br = netdev_priv(dev); 337 338 eth_hw_addr_random(dev); 339 ether_setup(dev); 340 341 dev->netdev_ops = &br_netdev_ops; 342 dev->destructor = br_dev_free; 343 SET_ETHTOOL_OPS(dev, &br_ethtool_ops); 344 SET_NETDEV_DEVTYPE(dev, &br_type); 345 dev->tx_queue_len = 0; 346 dev->priv_flags = IFF_EBRIDGE; 347 348 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | 349 NETIF_F_GSO_MASK | NETIF_F_HW_CSUM | NETIF_F_LLTX | 350 NETIF_F_NETNS_LOCAL | NETIF_F_HW_VLAN_TX; 351 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | 352 NETIF_F_GSO_MASK | NETIF_F_HW_CSUM | 353 NETIF_F_HW_VLAN_TX; 354 355 br->dev = dev; 356 spin_lock_init(&br->lock); 357 INIT_LIST_HEAD(&br->port_list); 358 spin_lock_init(&br->hash_lock); 359 360 br->bridge_id.prio[0] = 0x80; 361 br->bridge_id.prio[1] = 0x00; 362 363 memcpy(br->group_addr, br_group_address, ETH_ALEN); 364 365 br->stp_enabled = BR_NO_STP; 366 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 367 368 br->designated_root = br->bridge_id; 369 br->bridge_max_age = br->max_age = 20 * HZ; 370 br->bridge_hello_time = br->hello_time = 2 * HZ; 371 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 372 br->ageing_time = 300 * HZ; 373 374 br_netfilter_rtable_init(br); 375 br_stp_timer_init(br); 376 br_multicast_init(br); 377 } 378