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 rcu_read_lock(); 35 #ifdef CONFIG_BRIDGE_NETFILTER 36 if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { 37 br_nf_pre_routing_finish_bridge_slow(skb); 38 rcu_read_unlock(); 39 return NETDEV_TX_OK; 40 } 41 #endif 42 43 u64_stats_update_begin(&brstats->syncp); 44 brstats->tx_packets++; 45 brstats->tx_bytes += skb->len; 46 u64_stats_update_end(&brstats->syncp); 47 48 BR_INPUT_SKB_CB(skb)->brdev = dev; 49 50 skb_reset_mac_header(skb); 51 skb_pull(skb, ETH_HLEN); 52 53 if (is_broadcast_ether_addr(dest)) 54 br_flood_deliver(br, skb); 55 else if (is_multicast_ether_addr(dest)) { 56 if (unlikely(netpoll_tx_running(dev))) { 57 br_flood_deliver(br, skb); 58 goto out; 59 } 60 if (br_multicast_rcv(br, NULL, skb)) { 61 kfree_skb(skb); 62 goto out; 63 } 64 65 mdst = br_mdb_get(br, skb); 66 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) 67 br_multicast_deliver(mdst, skb); 68 else 69 br_flood_deliver(br, skb); 70 } else if ((dst = __br_fdb_get(br, dest)) != NULL) 71 br_deliver(dst->dst, skb); 72 else 73 br_flood_deliver(br, skb); 74 75 out: 76 rcu_read_unlock(); 77 return NETDEV_TX_OK; 78 } 79 80 static int br_dev_init(struct net_device *dev) 81 { 82 struct net_bridge *br = netdev_priv(dev); 83 84 br->stats = alloc_percpu(struct br_cpu_netstats); 85 if (!br->stats) 86 return -ENOMEM; 87 88 return 0; 89 } 90 91 static int br_dev_open(struct net_device *dev) 92 { 93 struct net_bridge *br = netdev_priv(dev); 94 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 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_bh(&bstats->syncp); 132 memcpy(&tmp, bstats, sizeof(tmp)); 133 } while (u64_stats_fetch_retry_bh(&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 -EADDRNOTAVAIL; 172 173 spin_lock_bh(&br->lock); 174 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 175 dev->addr_assign_type &= ~NET_ADDR_RANDOM; 176 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); 177 br_fdb_change_mac_address(br, addr->sa_data); 178 br_stp_change_bridge_id(br, addr->sa_data); 179 } 180 br->flags |= BR_SET_MAC_ADDR; 181 spin_unlock_bh(&br->lock); 182 183 return 0; 184 } 185 186 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 187 { 188 strcpy(info->driver, "bridge"); 189 strcpy(info->version, BR_VERSION); 190 strcpy(info->fw_version, "N/A"); 191 strcpy(info->bus_info, "N/A"); 192 } 193 194 static netdev_features_t br_fix_features(struct net_device *dev, 195 netdev_features_t features) 196 { 197 struct net_bridge *br = netdev_priv(dev); 198 199 return br_features_recompute(br, features); 200 } 201 202 #ifdef CONFIG_NET_POLL_CONTROLLER 203 static void br_poll_controller(struct net_device *br_dev) 204 { 205 } 206 207 static void br_netpoll_cleanup(struct net_device *dev) 208 { 209 struct net_bridge *br = netdev_priv(dev); 210 struct net_bridge_port *p; 211 212 list_for_each_entry(p, &br->port_list, list) 213 br_netpoll_disable(p); 214 } 215 216 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, 217 gfp_t gfp) 218 { 219 struct net_bridge *br = netdev_priv(dev); 220 struct net_bridge_port *p; 221 int err = 0; 222 223 list_for_each_entry(p, &br->port_list, list) { 224 if (!p->dev) 225 continue; 226 err = br_netpoll_enable(p, gfp); 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, gfp_t gfp) 240 { 241 struct netpoll *np; 242 int err = 0; 243 244 np = kzalloc(sizeof(*p->np), gfp); 245 err = -ENOMEM; 246 if (!np) 247 goto out; 248 249 err = __netpoll_setup(np, p->dev, gfp); 250 if (err) { 251 kfree(np); 252 goto out; 253 } 254 255 p->np = np; 256 257 out: 258 return err; 259 } 260 261 void br_netpoll_disable(struct net_bridge_port *p) 262 { 263 struct netpoll *np = p->np; 264 265 if (!np) 266 return; 267 268 p->np = NULL; 269 270 __netpoll_free_rcu(np); 271 } 272 273 #endif 274 275 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 276 277 { 278 struct net_bridge *br = netdev_priv(dev); 279 280 return br_add_if(br, slave_dev); 281 } 282 283 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 284 { 285 struct net_bridge *br = netdev_priv(dev); 286 287 return br_del_if(br, slave_dev); 288 } 289 290 static const struct ethtool_ops br_ethtool_ops = { 291 .get_drvinfo = br_getinfo, 292 .get_link = ethtool_op_get_link, 293 }; 294 295 static const struct net_device_ops br_netdev_ops = { 296 .ndo_open = br_dev_open, 297 .ndo_stop = br_dev_stop, 298 .ndo_init = br_dev_init, 299 .ndo_start_xmit = br_dev_xmit, 300 .ndo_get_stats64 = br_get_stats64, 301 .ndo_set_mac_address = br_set_mac_address, 302 .ndo_set_rx_mode = br_dev_set_multicast_list, 303 .ndo_change_mtu = br_change_mtu, 304 .ndo_do_ioctl = br_dev_ioctl, 305 #ifdef CONFIG_NET_POLL_CONTROLLER 306 .ndo_netpoll_setup = br_netpoll_setup, 307 .ndo_netpoll_cleanup = br_netpoll_cleanup, 308 .ndo_poll_controller = br_poll_controller, 309 #endif 310 .ndo_add_slave = br_add_slave, 311 .ndo_del_slave = br_del_slave, 312 .ndo_fix_features = br_fix_features, 313 .ndo_fdb_add = br_fdb_add, 314 .ndo_fdb_del = br_fdb_delete, 315 .ndo_fdb_dump = br_fdb_dump, 316 .ndo_bridge_getlink = br_getlink, 317 .ndo_bridge_setlink = br_setlink, 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 eth_hw_addr_random(dev); 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_HW_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_HW_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, eth_reserved_addr_base, ETH_ALEN); 362 363 br->stp_enabled = BR_NO_STP; 364 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 365 366 br->designated_root = br->bridge_id; 367 br->bridge_max_age = br->max_age = 20 * HZ; 368 br->bridge_hello_time = br->hello_time = 2 * HZ; 369 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 370 br->ageing_time = 300 * HZ; 371 372 br_netfilter_rtable_init(br); 373 br_stp_timer_init(br); 374 br_multicast_init(br); 375 } 376