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 netif_carrier_off(dev); 95 netdev_update_features(dev); 96 netif_start_queue(dev); 97 br_stp_enable_bridge(br); 98 br_multicast_open(br); 99 100 return 0; 101 } 102 103 static void br_dev_set_multicast_list(struct net_device *dev) 104 { 105 } 106 107 static int br_dev_stop(struct net_device *dev) 108 { 109 struct net_bridge *br = netdev_priv(dev); 110 111 netif_carrier_off(dev); 112 113 br_stp_disable_bridge(br); 114 br_multicast_stop(br); 115 116 netif_stop_queue(dev); 117 118 return 0; 119 } 120 121 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, 122 struct rtnl_link_stats64 *stats) 123 { 124 struct net_bridge *br = netdev_priv(dev); 125 struct br_cpu_netstats tmp, sum = { 0 }; 126 unsigned int cpu; 127 128 for_each_possible_cpu(cpu) { 129 unsigned int start; 130 const struct br_cpu_netstats *bstats 131 = per_cpu_ptr(br->stats, cpu); 132 do { 133 start = u64_stats_fetch_begin(&bstats->syncp); 134 memcpy(&tmp, bstats, sizeof(tmp)); 135 } while (u64_stats_fetch_retry(&bstats->syncp, start)); 136 sum.tx_bytes += tmp.tx_bytes; 137 sum.tx_packets += tmp.tx_packets; 138 sum.rx_bytes += tmp.rx_bytes; 139 sum.rx_packets += tmp.rx_packets; 140 } 141 142 stats->tx_bytes = sum.tx_bytes; 143 stats->tx_packets = sum.tx_packets; 144 stats->rx_bytes = sum.rx_bytes; 145 stats->rx_packets = sum.rx_packets; 146 147 return stats; 148 } 149 150 static int br_change_mtu(struct net_device *dev, int new_mtu) 151 { 152 struct net_bridge *br = netdev_priv(dev); 153 if (new_mtu < 68 || new_mtu > br_min_mtu(br)) 154 return -EINVAL; 155 156 dev->mtu = new_mtu; 157 158 #ifdef CONFIG_BRIDGE_NETFILTER 159 /* remember the MTU in the rtable for PMTU */ 160 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 161 #endif 162 163 return 0; 164 } 165 166 /* Allow setting mac address to any valid ethernet address. */ 167 static int br_set_mac_address(struct net_device *dev, void *p) 168 { 169 struct net_bridge *br = netdev_priv(dev); 170 struct sockaddr *addr = p; 171 172 if (!is_valid_ether_addr(addr->sa_data)) 173 return -EINVAL; 174 175 spin_lock_bh(&br->lock); 176 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); 177 br_stp_change_bridge_id(br, addr->sa_data); 178 br->flags |= BR_SET_MAC_ADDR; 179 spin_unlock_bh(&br->lock); 180 181 return 0; 182 } 183 184 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 185 { 186 strcpy(info->driver, "bridge"); 187 strcpy(info->version, BR_VERSION); 188 strcpy(info->fw_version, "N/A"); 189 strcpy(info->bus_info, "N/A"); 190 } 191 192 static u32 br_fix_features(struct net_device *dev, u32 features) 193 { 194 struct net_bridge *br = netdev_priv(dev); 195 196 return br_features_recompute(br, features); 197 } 198 199 #ifdef CONFIG_NET_POLL_CONTROLLER 200 static void br_poll_controller(struct net_device *br_dev) 201 { 202 } 203 204 static void br_netpoll_cleanup(struct net_device *dev) 205 { 206 struct net_bridge *br = netdev_priv(dev); 207 struct net_bridge_port *p, *n; 208 209 list_for_each_entry_safe(p, n, &br->port_list, list) { 210 br_netpoll_disable(p); 211 } 212 } 213 214 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 215 { 216 struct net_bridge *br = netdev_priv(dev); 217 struct net_bridge_port *p, *n; 218 int err = 0; 219 220 list_for_each_entry_safe(p, n, &br->port_list, list) { 221 if (!p->dev) 222 continue; 223 224 err = br_netpoll_enable(p); 225 if (err) 226 goto fail; 227 } 228 229 out: 230 return err; 231 232 fail: 233 br_netpoll_cleanup(dev); 234 goto out; 235 } 236 237 int br_netpoll_enable(struct net_bridge_port *p) 238 { 239 struct netpoll *np; 240 int err = 0; 241 242 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 243 err = -ENOMEM; 244 if (!np) 245 goto out; 246 247 np->dev = p->dev; 248 strlcpy(np->dev_name, p->dev->name, IFNAMSIZ); 249 250 err = __netpoll_setup(np); 251 if (err) { 252 kfree(np); 253 goto out; 254 } 255 256 p->np = np; 257 258 out: 259 return err; 260 } 261 262 void br_netpoll_disable(struct net_bridge_port *p) 263 { 264 struct netpoll *np = p->np; 265 266 if (!np) 267 return; 268 269 p->np = NULL; 270 271 /* Wait for transmitting packets to finish before freeing. */ 272 synchronize_rcu_bh(); 273 274 __netpoll_cleanup(np); 275 kfree(np); 276 } 277 278 #endif 279 280 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 281 282 { 283 struct net_bridge *br = netdev_priv(dev); 284 285 return br_add_if(br, slave_dev); 286 } 287 288 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 289 { 290 struct net_bridge *br = netdev_priv(dev); 291 292 return br_del_if(br, slave_dev); 293 } 294 295 static const struct ethtool_ops br_ethtool_ops = { 296 .get_drvinfo = br_getinfo, 297 .get_link = ethtool_op_get_link, 298 }; 299 300 static const struct net_device_ops br_netdev_ops = { 301 .ndo_open = br_dev_open, 302 .ndo_stop = br_dev_stop, 303 .ndo_init = br_dev_init, 304 .ndo_start_xmit = br_dev_xmit, 305 .ndo_get_stats64 = br_get_stats64, 306 .ndo_set_mac_address = br_set_mac_address, 307 .ndo_set_multicast_list = br_dev_set_multicast_list, 308 .ndo_change_mtu = br_change_mtu, 309 .ndo_do_ioctl = br_dev_ioctl, 310 #ifdef CONFIG_NET_POLL_CONTROLLER 311 .ndo_netpoll_setup = br_netpoll_setup, 312 .ndo_netpoll_cleanup = br_netpoll_cleanup, 313 .ndo_poll_controller = br_poll_controller, 314 #endif 315 .ndo_add_slave = br_add_slave, 316 .ndo_del_slave = br_del_slave, 317 .ndo_fix_features = br_fix_features, 318 }; 319 320 static void br_dev_free(struct net_device *dev) 321 { 322 struct net_bridge *br = netdev_priv(dev); 323 324 free_percpu(br->stats); 325 free_netdev(dev); 326 } 327 328 static struct device_type br_type = { 329 .name = "bridge", 330 }; 331 332 void br_dev_setup(struct net_device *dev) 333 { 334 struct net_bridge *br = netdev_priv(dev); 335 336 random_ether_addr(dev->dev_addr); 337 ether_setup(dev); 338 339 dev->netdev_ops = &br_netdev_ops; 340 dev->destructor = br_dev_free; 341 SET_ETHTOOL_OPS(dev, &br_ethtool_ops); 342 SET_NETDEV_DEVTYPE(dev, &br_type); 343 dev->tx_queue_len = 0; 344 dev->priv_flags = IFF_EBRIDGE; 345 346 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | 347 NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX | 348 NETIF_F_NETNS_LOCAL | NETIF_F_HW_VLAN_TX; 349 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | 350 NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | 351 NETIF_F_HW_VLAN_TX; 352 353 br->dev = dev; 354 spin_lock_init(&br->lock); 355 INIT_LIST_HEAD(&br->port_list); 356 spin_lock_init(&br->hash_lock); 357 358 br->bridge_id.prio[0] = 0x80; 359 br->bridge_id.prio[1] = 0x00; 360 361 memcpy(br->group_addr, br_group_address, ETH_ALEN); 362 363 br->stp_enabled = BR_NO_STP; 364 br->designated_root = br->bridge_id; 365 br->bridge_max_age = br->max_age = 20 * HZ; 366 br->bridge_hello_time = br->hello_time = 2 * HZ; 367 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 368 br->ageing_time = 300 * HZ; 369 370 br_netfilter_rtable_init(br); 371 br_stp_timer_init(br); 372 br_multicast_init(br); 373 } 374