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 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); 174 br_stp_change_bridge_id(br, addr->sa_data); 175 br->flags |= BR_SET_MAC_ADDR; 176 spin_unlock_bh(&br->lock); 177 178 return 0; 179 } 180 181 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 182 { 183 strcpy(info->driver, "bridge"); 184 strcpy(info->version, BR_VERSION); 185 strcpy(info->fw_version, "N/A"); 186 strcpy(info->bus_info, "N/A"); 187 } 188 189 static u32 br_fix_features(struct net_device *dev, u32 features) 190 { 191 struct net_bridge *br = netdev_priv(dev); 192 193 return br_features_recompute(br, features); 194 } 195 196 #ifdef CONFIG_NET_POLL_CONTROLLER 197 static void br_poll_controller(struct net_device *br_dev) 198 { 199 } 200 201 static void br_netpoll_cleanup(struct net_device *dev) 202 { 203 struct net_bridge *br = netdev_priv(dev); 204 struct net_bridge_port *p, *n; 205 206 list_for_each_entry_safe(p, n, &br->port_list, list) { 207 br_netpoll_disable(p); 208 } 209 } 210 211 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 212 { 213 struct net_bridge *br = netdev_priv(dev); 214 struct net_bridge_port *p, *n; 215 int err = 0; 216 217 list_for_each_entry_safe(p, n, &br->port_list, list) { 218 if (!p->dev) 219 continue; 220 221 err = br_netpoll_enable(p); 222 if (err) 223 goto fail; 224 } 225 226 out: 227 return err; 228 229 fail: 230 br_netpoll_cleanup(dev); 231 goto out; 232 } 233 234 int br_netpoll_enable(struct net_bridge_port *p) 235 { 236 struct netpoll *np; 237 int err = 0; 238 239 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 240 err = -ENOMEM; 241 if (!np) 242 goto out; 243 244 np->dev = p->dev; 245 strlcpy(np->dev_name, p->dev->name, IFNAMSIZ); 246 247 err = __netpoll_setup(np); 248 if (err) { 249 kfree(np); 250 goto out; 251 } 252 253 p->np = np; 254 255 out: 256 return err; 257 } 258 259 void br_netpoll_disable(struct net_bridge_port *p) 260 { 261 struct netpoll *np = p->np; 262 263 if (!np) 264 return; 265 266 p->np = NULL; 267 268 /* Wait for transmitting packets to finish before freeing. */ 269 synchronize_rcu_bh(); 270 271 __netpoll_cleanup(np); 272 kfree(np); 273 } 274 275 #endif 276 277 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 278 279 { 280 struct net_bridge *br = netdev_priv(dev); 281 282 return br_add_if(br, slave_dev); 283 } 284 285 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 286 { 287 struct net_bridge *br = netdev_priv(dev); 288 289 return br_del_if(br, slave_dev); 290 } 291 292 static const struct ethtool_ops br_ethtool_ops = { 293 .get_drvinfo = br_getinfo, 294 .get_link = ethtool_op_get_link, 295 }; 296 297 static const struct net_device_ops br_netdev_ops = { 298 .ndo_open = br_dev_open, 299 .ndo_stop = br_dev_stop, 300 .ndo_init = br_dev_init, 301 .ndo_start_xmit = br_dev_xmit, 302 .ndo_get_stats64 = br_get_stats64, 303 .ndo_set_mac_address = br_set_mac_address, 304 .ndo_set_rx_mode = br_dev_set_multicast_list, 305 .ndo_change_mtu = br_change_mtu, 306 .ndo_do_ioctl = br_dev_ioctl, 307 #ifdef CONFIG_NET_POLL_CONTROLLER 308 .ndo_netpoll_setup = br_netpoll_setup, 309 .ndo_netpoll_cleanup = br_netpoll_cleanup, 310 .ndo_poll_controller = br_poll_controller, 311 #endif 312 .ndo_add_slave = br_add_slave, 313 .ndo_del_slave = br_del_slave, 314 .ndo_fix_features = br_fix_features, 315 }; 316 317 static void br_dev_free(struct net_device *dev) 318 { 319 struct net_bridge *br = netdev_priv(dev); 320 321 free_percpu(br->stats); 322 free_netdev(dev); 323 } 324 325 static struct device_type br_type = { 326 .name = "bridge", 327 }; 328 329 void br_dev_setup(struct net_device *dev) 330 { 331 struct net_bridge *br = netdev_priv(dev); 332 333 random_ether_addr(dev->dev_addr); 334 ether_setup(dev); 335 336 dev->netdev_ops = &br_netdev_ops; 337 dev->destructor = br_dev_free; 338 SET_ETHTOOL_OPS(dev, &br_ethtool_ops); 339 SET_NETDEV_DEVTYPE(dev, &br_type); 340 dev->tx_queue_len = 0; 341 dev->priv_flags = IFF_EBRIDGE; 342 343 dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | 344 NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX | 345 NETIF_F_NETNS_LOCAL | NETIF_F_HW_VLAN_TX; 346 dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | 347 NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | 348 NETIF_F_HW_VLAN_TX; 349 350 br->dev = dev; 351 spin_lock_init(&br->lock); 352 INIT_LIST_HEAD(&br->port_list); 353 spin_lock_init(&br->hash_lock); 354 355 br->bridge_id.prio[0] = 0x80; 356 br->bridge_id.prio[1] = 0x00; 357 358 memcpy(br->group_addr, br_group_address, ETH_ALEN); 359 360 br->stp_enabled = BR_NO_STP; 361 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 362 363 br->designated_root = br->bridge_id; 364 br->bridge_max_age = br->max_age = 20 * HZ; 365 br->bridge_hello_time = br->hello_time = 2 * HZ; 366 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 367 br->ageing_time = 300 * HZ; 368 369 br_netfilter_rtable_init(br); 370 br_stp_timer_init(br); 371 br_multicast_init(br); 372 } 373