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 -EINVAL; 171 172 spin_lock_bh(&br->lock); 173 if (compare_ether_addr(dev->dev_addr, addr->sa_data)) { 174 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); 175 br_fdb_change_mac_address(br, addr->sa_data); 176 br_stp_change_bridge_id(br, addr->sa_data); 177 } 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 netdev_features_t br_fix_features(struct net_device *dev, 193 netdev_features_t features) 194 { 195 struct net_bridge *br = netdev_priv(dev); 196 197 return br_features_recompute(br, features); 198 } 199 200 #ifdef CONFIG_NET_POLL_CONTROLLER 201 static void br_poll_controller(struct net_device *br_dev) 202 { 203 } 204 205 static void br_netpoll_cleanup(struct net_device *dev) 206 { 207 struct net_bridge *br = netdev_priv(dev); 208 struct net_bridge_port *p, *n; 209 210 list_for_each_entry_safe(p, n, &br->port_list, list) { 211 br_netpoll_disable(p); 212 } 213 } 214 215 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 216 { 217 struct net_bridge *br = netdev_priv(dev); 218 struct net_bridge_port *p, *n; 219 int err = 0; 220 221 list_for_each_entry_safe(p, n, &br->port_list, list) { 222 if (!p->dev) 223 continue; 224 225 err = br_netpoll_enable(p); 226 if (err) 227 goto fail; 228 } 229 230 out: 231 return err; 232 233 fail: 234 br_netpoll_cleanup(dev); 235 goto out; 236 } 237 238 int br_netpoll_enable(struct net_bridge_port *p) 239 { 240 struct netpoll *np; 241 int err = 0; 242 243 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 244 err = -ENOMEM; 245 if (!np) 246 goto out; 247 248 np->dev = p->dev; 249 strlcpy(np->dev_name, p->dev->name, IFNAMSIZ); 250 251 err = __netpoll_setup(np); 252 if (err) { 253 kfree(np); 254 goto out; 255 } 256 257 p->np = np; 258 259 out: 260 return err; 261 } 262 263 void br_netpoll_disable(struct net_bridge_port *p) 264 { 265 struct netpoll *np = p->np; 266 267 if (!np) 268 return; 269 270 p->np = NULL; 271 272 /* Wait for transmitting packets to finish before freeing. */ 273 synchronize_rcu_bh(); 274 275 __netpoll_cleanup(np); 276 kfree(np); 277 } 278 279 #endif 280 281 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 282 283 { 284 struct net_bridge *br = netdev_priv(dev); 285 286 return br_add_if(br, slave_dev); 287 } 288 289 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 290 { 291 struct net_bridge *br = netdev_priv(dev); 292 293 return br_del_if(br, slave_dev); 294 } 295 296 static const struct ethtool_ops br_ethtool_ops = { 297 .get_drvinfo = br_getinfo, 298 .get_link = ethtool_op_get_link, 299 }; 300 301 static const struct net_device_ops br_netdev_ops = { 302 .ndo_open = br_dev_open, 303 .ndo_stop = br_dev_stop, 304 .ndo_init = br_dev_init, 305 .ndo_start_xmit = br_dev_xmit, 306 .ndo_get_stats64 = br_get_stats64, 307 .ndo_set_mac_address = br_set_mac_address, 308 .ndo_set_rx_mode = br_dev_set_multicast_list, 309 .ndo_change_mtu = br_change_mtu, 310 .ndo_do_ioctl = br_dev_ioctl, 311 #ifdef CONFIG_NET_POLL_CONTROLLER 312 .ndo_netpoll_setup = br_netpoll_setup, 313 .ndo_netpoll_cleanup = br_netpoll_cleanup, 314 .ndo_poll_controller = br_poll_controller, 315 #endif 316 .ndo_add_slave = br_add_slave, 317 .ndo_del_slave = br_del_slave, 318 .ndo_fix_features = br_fix_features, 319 }; 320 321 static void br_dev_free(struct net_device *dev) 322 { 323 struct net_bridge *br = netdev_priv(dev); 324 325 free_percpu(br->stats); 326 free_netdev(dev); 327 } 328 329 static struct device_type br_type = { 330 .name = "bridge", 331 }; 332 333 void br_dev_setup(struct net_device *dev) 334 { 335 struct net_bridge *br = netdev_priv(dev); 336 337 random_ether_addr(dev->dev_addr); 338 ether_setup(dev); 339 340 dev->netdev_ops = &br_netdev_ops; 341 dev->destructor = br_dev_free; 342 SET_ETHTOOL_OPS(dev, &br_ethtool_ops); 343 SET_NETDEV_DEVTYPE(dev, &br_type); 344 dev->tx_queue_len = 0; 345 dev->priv_flags = IFF_EBRIDGE; 346 347 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | 348 NETIF_F_GSO_MASK | NETIF_F_HW_CSUM | NETIF_F_LLTX | 349 NETIF_F_NETNS_LOCAL | NETIF_F_HW_VLAN_TX; 350 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | 351 NETIF_F_GSO_MASK | NETIF_F_HW_CSUM | 352 NETIF_F_HW_VLAN_TX; 353 354 br->dev = dev; 355 spin_lock_init(&br->lock); 356 INIT_LIST_HEAD(&br->port_list); 357 spin_lock_init(&br->hash_lock); 358 359 br->bridge_id.prio[0] = 0x80; 360 br->bridge_id.prio[1] = 0x00; 361 362 memcpy(br->group_addr, br_group_address, ETH_ALEN); 363 364 br->stp_enabled = BR_NO_STP; 365 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 366 367 br->designated_root = br->bridge_id; 368 br->bridge_max_age = br->max_age = 20 * HZ; 369 br->bridge_hello_time = br->hello_time = 2 * HZ; 370 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 371 br->ageing_time = 300 * HZ; 372 373 br_netfilter_rtable_init(br); 374 br_stp_timer_init(br); 375 br_multicast_init(br); 376 } 377