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_multicast_ether_addr(dest)) { 53 if (unlikely(netpoll_tx_running(dev))) { 54 br_flood_deliver(br, skb); 55 goto out; 56 } 57 if (br_multicast_rcv(br, NULL, skb)) { 58 kfree_skb(skb); 59 goto out; 60 } 61 62 mdst = br_mdb_get(br, skb); 63 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) 64 br_multicast_deliver(mdst, skb); 65 else 66 br_flood_deliver(br, skb); 67 } else if ((dst = __br_fdb_get(br, dest)) != NULL) 68 br_deliver(dst->dst, skb); 69 else 70 br_flood_deliver(br, skb); 71 72 out: 73 rcu_read_unlock(); 74 return NETDEV_TX_OK; 75 } 76 77 static int br_dev_init(struct net_device *dev) 78 { 79 struct net_bridge *br = netdev_priv(dev); 80 81 br->stats = alloc_percpu(struct br_cpu_netstats); 82 if (!br->stats) 83 return -ENOMEM; 84 85 return 0; 86 } 87 88 static int br_dev_open(struct net_device *dev) 89 { 90 struct net_bridge *br = netdev_priv(dev); 91 92 netif_carrier_off(dev); 93 netdev_update_features(dev); 94 netif_start_queue(dev); 95 br_stp_enable_bridge(br); 96 br_multicast_open(br); 97 98 return 0; 99 } 100 101 static void br_dev_set_multicast_list(struct net_device *dev) 102 { 103 } 104 105 static int br_dev_stop(struct net_device *dev) 106 { 107 struct net_bridge *br = netdev_priv(dev); 108 109 netif_carrier_off(dev); 110 111 br_stp_disable_bridge(br); 112 br_multicast_stop(br); 113 114 netif_stop_queue(dev); 115 116 return 0; 117 } 118 119 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, 120 struct rtnl_link_stats64 *stats) 121 { 122 struct net_bridge *br = netdev_priv(dev); 123 struct br_cpu_netstats tmp, sum = { 0 }; 124 unsigned int cpu; 125 126 for_each_possible_cpu(cpu) { 127 unsigned int start; 128 const struct br_cpu_netstats *bstats 129 = per_cpu_ptr(br->stats, cpu); 130 do { 131 start = u64_stats_fetch_begin(&bstats->syncp); 132 memcpy(&tmp, bstats, sizeof(tmp)); 133 } while (u64_stats_fetch_retry(&bstats->syncp, start)); 134 sum.tx_bytes += tmp.tx_bytes; 135 sum.tx_packets += tmp.tx_packets; 136 sum.rx_bytes += tmp.rx_bytes; 137 sum.rx_packets += tmp.rx_packets; 138 } 139 140 stats->tx_bytes = sum.tx_bytes; 141 stats->tx_packets = sum.tx_packets; 142 stats->rx_bytes = sum.rx_bytes; 143 stats->rx_packets = sum.rx_packets; 144 145 return stats; 146 } 147 148 static int br_change_mtu(struct net_device *dev, int new_mtu) 149 { 150 struct net_bridge *br = netdev_priv(dev); 151 if (new_mtu < 68 || new_mtu > br_min_mtu(br)) 152 return -EINVAL; 153 154 dev->mtu = new_mtu; 155 156 #ifdef CONFIG_BRIDGE_NETFILTER 157 /* remember the MTU in the rtable for PMTU */ 158 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 159 #endif 160 161 return 0; 162 } 163 164 /* Allow setting mac address to any valid ethernet address. */ 165 static int br_set_mac_address(struct net_device *dev, void *p) 166 { 167 struct net_bridge *br = netdev_priv(dev); 168 struct sockaddr *addr = p; 169 170 if (!is_valid_ether_addr(addr->sa_data)) 171 return -EINVAL; 172 173 spin_lock_bh(&br->lock); 174 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); 175 br_stp_change_bridge_id(br, addr->sa_data); 176 br->flags |= BR_SET_MAC_ADDR; 177 spin_unlock_bh(&br->lock); 178 179 return 0; 180 } 181 182 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 183 { 184 strcpy(info->driver, "bridge"); 185 strcpy(info->version, BR_VERSION); 186 strcpy(info->fw_version, "N/A"); 187 strcpy(info->bus_info, "N/A"); 188 } 189 190 static u32 br_fix_features(struct net_device *dev, u32 features) 191 { 192 struct net_bridge *br = netdev_priv(dev); 193 194 return br_features_recompute(br, features); 195 } 196 197 #ifdef CONFIG_NET_POLL_CONTROLLER 198 static void br_poll_controller(struct net_device *br_dev) 199 { 200 } 201 202 static void br_netpoll_cleanup(struct net_device *dev) 203 { 204 struct net_bridge *br = netdev_priv(dev); 205 struct net_bridge_port *p, *n; 206 207 list_for_each_entry_safe(p, n, &br->port_list, list) { 208 br_netpoll_disable(p); 209 } 210 } 211 212 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) 213 { 214 struct net_bridge *br = netdev_priv(dev); 215 struct net_bridge_port *p, *n; 216 int err = 0; 217 218 list_for_each_entry_safe(p, n, &br->port_list, list) { 219 if (!p->dev) 220 continue; 221 222 err = br_netpoll_enable(p); 223 if (err) 224 goto fail; 225 } 226 227 out: 228 return err; 229 230 fail: 231 br_netpoll_cleanup(dev); 232 goto out; 233 } 234 235 int br_netpoll_enable(struct net_bridge_port *p) 236 { 237 struct netpoll *np; 238 int err = 0; 239 240 np = kzalloc(sizeof(*p->np), GFP_KERNEL); 241 err = -ENOMEM; 242 if (!np) 243 goto out; 244 245 np->dev = p->dev; 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_multicast_list = 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->designated_root = br->bridge_id; 362 br->bridge_max_age = br->max_age = 20 * HZ; 363 br->bridge_hello_time = br->hello_time = 2 * HZ; 364 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 365 br->ageing_time = 300 * HZ; 366 367 br_netfilter_rtable_init(br); 368 br_stp_timer_init(br); 369 br_multicast_init(br); 370 } 371