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 #define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \ 26 NETIF_F_GSO_MASK | NETIF_F_HW_CSUM) 27 28 /* net device transmit always called with BH disabled */ 29 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) 30 { 31 struct net_bridge *br = netdev_priv(dev); 32 const unsigned char *dest = skb->data; 33 struct net_bridge_fdb_entry *dst; 34 struct net_bridge_mdb_entry *mdst; 35 struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); 36 u16 vid = 0; 37 38 rcu_read_lock(); 39 #ifdef CONFIG_BRIDGE_NETFILTER 40 if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) { 41 br_nf_pre_routing_finish_bridge_slow(skb); 42 rcu_read_unlock(); 43 return NETDEV_TX_OK; 44 } 45 #endif 46 47 u64_stats_update_begin(&brstats->syncp); 48 brstats->tx_packets++; 49 brstats->tx_bytes += skb->len; 50 u64_stats_update_end(&brstats->syncp); 51 52 if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid)) 53 goto out; 54 55 BR_INPUT_SKB_CB(skb)->brdev = dev; 56 57 skb_reset_mac_header(skb); 58 skb_pull(skb, ETH_HLEN); 59 60 if (is_broadcast_ether_addr(dest)) 61 br_flood_deliver(br, skb, false); 62 else if (is_multicast_ether_addr(dest)) { 63 if (unlikely(netpoll_tx_running(dev))) { 64 br_flood_deliver(br, skb, false); 65 goto out; 66 } 67 if (br_multicast_rcv(br, NULL, skb, vid)) { 68 kfree_skb(skb); 69 goto out; 70 } 71 72 mdst = br_mdb_get(br, skb, vid); 73 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && 74 br_multicast_querier_exists(br, eth_hdr(skb))) 75 br_multicast_deliver(mdst, skb); 76 else 77 br_flood_deliver(br, skb, false); 78 } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL) 79 br_deliver(dst->dst, skb); 80 else 81 br_flood_deliver(br, skb, true); 82 83 out: 84 rcu_read_unlock(); 85 return NETDEV_TX_OK; 86 } 87 88 static int br_dev_init(struct net_device *dev) 89 { 90 struct net_bridge *br = netdev_priv(dev); 91 int i; 92 93 br->stats = alloc_percpu(struct pcpu_sw_netstats); 94 if (!br->stats) 95 return -ENOMEM; 96 97 for_each_possible_cpu(i) { 98 struct pcpu_sw_netstats *br_dev_stats; 99 br_dev_stats = per_cpu_ptr(br->stats, i); 100 u64_stats_init(&br_dev_stats->syncp); 101 } 102 103 return 0; 104 } 105 106 static int br_dev_open(struct net_device *dev) 107 { 108 struct net_bridge *br = netdev_priv(dev); 109 110 netdev_update_features(dev); 111 netif_start_queue(dev); 112 br_stp_enable_bridge(br); 113 br_multicast_open(br); 114 115 return 0; 116 } 117 118 static void br_dev_set_multicast_list(struct net_device *dev) 119 { 120 } 121 122 static int br_dev_stop(struct net_device *dev) 123 { 124 struct net_bridge *br = netdev_priv(dev); 125 126 br_stp_disable_bridge(br); 127 br_multicast_stop(br); 128 129 netif_stop_queue(dev); 130 131 return 0; 132 } 133 134 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, 135 struct rtnl_link_stats64 *stats) 136 { 137 struct net_bridge *br = netdev_priv(dev); 138 struct pcpu_sw_netstats tmp, sum = { 0 }; 139 unsigned int cpu; 140 141 for_each_possible_cpu(cpu) { 142 unsigned int start; 143 const struct pcpu_sw_netstats *bstats 144 = per_cpu_ptr(br->stats, cpu); 145 do { 146 start = u64_stats_fetch_begin_bh(&bstats->syncp); 147 memcpy(&tmp, bstats, sizeof(tmp)); 148 } while (u64_stats_fetch_retry_bh(&bstats->syncp, start)); 149 sum.tx_bytes += tmp.tx_bytes; 150 sum.tx_packets += tmp.tx_packets; 151 sum.rx_bytes += tmp.rx_bytes; 152 sum.rx_packets += tmp.rx_packets; 153 } 154 155 stats->tx_bytes = sum.tx_bytes; 156 stats->tx_packets = sum.tx_packets; 157 stats->rx_bytes = sum.rx_bytes; 158 stats->rx_packets = sum.rx_packets; 159 160 return stats; 161 } 162 163 static int br_change_mtu(struct net_device *dev, int new_mtu) 164 { 165 struct net_bridge *br = netdev_priv(dev); 166 if (new_mtu < 68 || new_mtu > br_min_mtu(br)) 167 return -EINVAL; 168 169 dev->mtu = new_mtu; 170 171 #ifdef CONFIG_BRIDGE_NETFILTER 172 /* remember the MTU in the rtable for PMTU */ 173 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 174 #endif 175 176 return 0; 177 } 178 179 /* Allow setting mac address to any valid ethernet address. */ 180 static int br_set_mac_address(struct net_device *dev, void *p) 181 { 182 struct net_bridge *br = netdev_priv(dev); 183 struct sockaddr *addr = p; 184 185 if (!is_valid_ether_addr(addr->sa_data)) 186 return -EADDRNOTAVAIL; 187 188 spin_lock_bh(&br->lock); 189 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 190 /* Mac address will be changed in br_stp_change_bridge_id(). */ 191 br_stp_change_bridge_id(br, addr->sa_data); 192 } 193 spin_unlock_bh(&br->lock); 194 195 return 0; 196 } 197 198 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 199 { 200 strlcpy(info->driver, "bridge", sizeof(info->driver)); 201 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 202 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 203 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 204 } 205 206 static netdev_features_t br_fix_features(struct net_device *dev, 207 netdev_features_t features) 208 { 209 struct net_bridge *br = netdev_priv(dev); 210 211 return br_features_recompute(br, features); 212 } 213 214 #ifdef CONFIG_NET_POLL_CONTROLLER 215 static void br_poll_controller(struct net_device *br_dev) 216 { 217 } 218 219 static void br_netpoll_cleanup(struct net_device *dev) 220 { 221 struct net_bridge *br = netdev_priv(dev); 222 struct net_bridge_port *p; 223 224 list_for_each_entry(p, &br->port_list, list) 225 br_netpoll_disable(p); 226 } 227 228 static int __br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp) 229 { 230 struct netpoll *np; 231 int err; 232 233 np = kzalloc(sizeof(*p->np), gfp); 234 if (!np) 235 return -ENOMEM; 236 237 err = __netpoll_setup(np, p->dev, gfp); 238 if (err) { 239 kfree(np); 240 return err; 241 } 242 243 p->np = np; 244 return err; 245 } 246 247 int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp) 248 { 249 if (!p->br->dev->npinfo) 250 return 0; 251 252 return __br_netpoll_enable(p, gfp); 253 } 254 255 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, 256 gfp_t gfp) 257 { 258 struct net_bridge *br = netdev_priv(dev); 259 struct net_bridge_port *p; 260 int err = 0; 261 262 list_for_each_entry(p, &br->port_list, list) { 263 if (!p->dev) 264 continue; 265 err = __br_netpoll_enable(p, gfp); 266 if (err) 267 goto fail; 268 } 269 270 out: 271 return err; 272 273 fail: 274 br_netpoll_cleanup(dev); 275 goto out; 276 } 277 278 void br_netpoll_disable(struct net_bridge_port *p) 279 { 280 struct netpoll *np = p->np; 281 282 if (!np) 283 return; 284 285 p->np = NULL; 286 287 __netpoll_free_async(np); 288 } 289 290 #endif 291 292 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 293 294 { 295 struct net_bridge *br = netdev_priv(dev); 296 297 return br_add_if(br, slave_dev); 298 } 299 300 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 301 { 302 struct net_bridge *br = netdev_priv(dev); 303 304 return br_del_if(br, slave_dev); 305 } 306 307 static const struct ethtool_ops br_ethtool_ops = { 308 .get_drvinfo = br_getinfo, 309 .get_link = ethtool_op_get_link, 310 }; 311 312 static const struct net_device_ops br_netdev_ops = { 313 .ndo_open = br_dev_open, 314 .ndo_stop = br_dev_stop, 315 .ndo_init = br_dev_init, 316 .ndo_start_xmit = br_dev_xmit, 317 .ndo_get_stats64 = br_get_stats64, 318 .ndo_set_mac_address = br_set_mac_address, 319 .ndo_set_rx_mode = br_dev_set_multicast_list, 320 .ndo_change_mtu = br_change_mtu, 321 .ndo_do_ioctl = br_dev_ioctl, 322 #ifdef CONFIG_NET_POLL_CONTROLLER 323 .ndo_netpoll_setup = br_netpoll_setup, 324 .ndo_netpoll_cleanup = br_netpoll_cleanup, 325 .ndo_poll_controller = br_poll_controller, 326 #endif 327 .ndo_add_slave = br_add_slave, 328 .ndo_del_slave = br_del_slave, 329 .ndo_fix_features = br_fix_features, 330 .ndo_fdb_add = br_fdb_add, 331 .ndo_fdb_del = br_fdb_delete, 332 .ndo_fdb_dump = br_fdb_dump, 333 .ndo_bridge_getlink = br_getlink, 334 .ndo_bridge_setlink = br_setlink, 335 .ndo_bridge_dellink = br_dellink, 336 }; 337 338 static void br_dev_free(struct net_device *dev) 339 { 340 struct net_bridge *br = netdev_priv(dev); 341 342 free_percpu(br->stats); 343 free_netdev(dev); 344 } 345 346 static struct device_type br_type = { 347 .name = "bridge", 348 }; 349 350 void br_dev_setup(struct net_device *dev) 351 { 352 struct net_bridge *br = netdev_priv(dev); 353 354 eth_hw_addr_random(dev); 355 ether_setup(dev); 356 357 dev->netdev_ops = &br_netdev_ops; 358 dev->destructor = br_dev_free; 359 SET_ETHTOOL_OPS(dev, &br_ethtool_ops); 360 SET_NETDEV_DEVTYPE(dev, &br_type); 361 dev->tx_queue_len = 0; 362 dev->priv_flags = IFF_EBRIDGE; 363 364 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 365 NETIF_F_HW_VLAN_CTAG_TX; 366 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX; 367 dev->vlan_features = COMMON_FEATURES; 368 369 br->dev = dev; 370 spin_lock_init(&br->lock); 371 INIT_LIST_HEAD(&br->port_list); 372 spin_lock_init(&br->hash_lock); 373 374 br->bridge_id.prio[0] = 0x80; 375 br->bridge_id.prio[1] = 0x00; 376 377 memcpy(br->group_addr, eth_reserved_addr_base, ETH_ALEN); 378 379 br->stp_enabled = BR_NO_STP; 380 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 381 382 br->designated_root = br->bridge_id; 383 br->bridge_max_age = br->max_age = 20 * HZ; 384 br->bridge_hello_time = br->hello_time = 2 * HZ; 385 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 386 br->ageing_time = 300 * HZ; 387 388 br_netfilter_rtable_init(br); 389 br_stp_timer_init(br); 390 br_multicast_init(br); 391 } 392