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 br_cpu_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 br_cpu_netstats); 94 if (!br->stats) 95 return -ENOMEM; 96 97 for_each_possible_cpu(i) { 98 struct br_cpu_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 br_cpu_netstats tmp, sum = { 0 }; 139 unsigned int cpu; 140 141 for_each_possible_cpu(cpu) { 142 unsigned int start; 143 const struct br_cpu_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 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); 191 br_fdb_change_mac_address(br, addr->sa_data); 192 br_stp_change_bridge_id(br, addr->sa_data); 193 } 194 spin_unlock_bh(&br->lock); 195 196 return 0; 197 } 198 199 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 200 { 201 strlcpy(info->driver, "bridge", sizeof(info->driver)); 202 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 203 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 204 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 205 } 206 207 static netdev_features_t br_fix_features(struct net_device *dev, 208 netdev_features_t features) 209 { 210 struct net_bridge *br = netdev_priv(dev); 211 212 return br_features_recompute(br, features); 213 } 214 215 #ifdef CONFIG_NET_POLL_CONTROLLER 216 static void br_poll_controller(struct net_device *br_dev) 217 { 218 } 219 220 static void br_netpoll_cleanup(struct net_device *dev) 221 { 222 struct net_bridge *br = netdev_priv(dev); 223 struct net_bridge_port *p; 224 225 list_for_each_entry(p, &br->port_list, list) 226 br_netpoll_disable(p); 227 } 228 229 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, 230 gfp_t gfp) 231 { 232 struct net_bridge *br = netdev_priv(dev); 233 struct net_bridge_port *p; 234 int err = 0; 235 236 list_for_each_entry(p, &br->port_list, list) { 237 if (!p->dev) 238 continue; 239 err = br_netpoll_enable(p, gfp); 240 if (err) 241 goto fail; 242 } 243 244 out: 245 return err; 246 247 fail: 248 br_netpoll_cleanup(dev); 249 goto out; 250 } 251 252 int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp) 253 { 254 struct netpoll *np; 255 int err; 256 257 if (!p->br->dev->npinfo) 258 return 0; 259 260 np = kzalloc(sizeof(*p->np), gfp); 261 if (!np) 262 return -ENOMEM; 263 264 err = __netpoll_setup(np, p->dev, gfp); 265 if (err) { 266 kfree(np); 267 return err; 268 } 269 270 p->np = np; 271 return err; 272 } 273 274 void br_netpoll_disable(struct net_bridge_port *p) 275 { 276 struct netpoll *np = p->np; 277 278 if (!np) 279 return; 280 281 p->np = NULL; 282 283 __netpoll_free_async(np); 284 } 285 286 #endif 287 288 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 289 290 { 291 struct net_bridge *br = netdev_priv(dev); 292 293 return br_add_if(br, slave_dev); 294 } 295 296 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 297 { 298 struct net_bridge *br = netdev_priv(dev); 299 300 return br_del_if(br, slave_dev); 301 } 302 303 static const struct ethtool_ops br_ethtool_ops = { 304 .get_drvinfo = br_getinfo, 305 .get_link = ethtool_op_get_link, 306 }; 307 308 static const struct net_device_ops br_netdev_ops = { 309 .ndo_open = br_dev_open, 310 .ndo_stop = br_dev_stop, 311 .ndo_init = br_dev_init, 312 .ndo_start_xmit = br_dev_xmit, 313 .ndo_get_stats64 = br_get_stats64, 314 .ndo_set_mac_address = br_set_mac_address, 315 .ndo_set_rx_mode = br_dev_set_multicast_list, 316 .ndo_change_mtu = br_change_mtu, 317 .ndo_do_ioctl = br_dev_ioctl, 318 #ifdef CONFIG_NET_POLL_CONTROLLER 319 .ndo_netpoll_setup = br_netpoll_setup, 320 .ndo_netpoll_cleanup = br_netpoll_cleanup, 321 .ndo_poll_controller = br_poll_controller, 322 #endif 323 .ndo_add_slave = br_add_slave, 324 .ndo_del_slave = br_del_slave, 325 .ndo_fix_features = br_fix_features, 326 .ndo_fdb_add = br_fdb_add, 327 .ndo_fdb_del = br_fdb_delete, 328 .ndo_fdb_dump = br_fdb_dump, 329 .ndo_bridge_getlink = br_getlink, 330 .ndo_bridge_setlink = br_setlink, 331 .ndo_bridge_dellink = br_dellink, 332 }; 333 334 static void br_dev_free(struct net_device *dev) 335 { 336 struct net_bridge *br = netdev_priv(dev); 337 338 free_percpu(br->stats); 339 free_netdev(dev); 340 } 341 342 static struct device_type br_type = { 343 .name = "bridge", 344 }; 345 346 void br_dev_setup(struct net_device *dev) 347 { 348 struct net_bridge *br = netdev_priv(dev); 349 350 eth_hw_addr_random(dev); 351 ether_setup(dev); 352 353 dev->netdev_ops = &br_netdev_ops; 354 dev->destructor = br_dev_free; 355 SET_ETHTOOL_OPS(dev, &br_ethtool_ops); 356 SET_NETDEV_DEVTYPE(dev, &br_type); 357 dev->tx_queue_len = 0; 358 dev->priv_flags = IFF_EBRIDGE; 359 360 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 361 NETIF_F_HW_VLAN_CTAG_TX; 362 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX; 363 dev->vlan_features = COMMON_FEATURES; 364 365 br->dev = dev; 366 spin_lock_init(&br->lock); 367 INIT_LIST_HEAD(&br->port_list); 368 spin_lock_init(&br->hash_lock); 369 370 br->bridge_id.prio[0] = 0x80; 371 br->bridge_id.prio[1] = 0x00; 372 373 memcpy(br->group_addr, eth_reserved_addr_base, ETH_ALEN); 374 375 br->stp_enabled = BR_NO_STP; 376 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 377 378 br->designated_root = br->bridge_id; 379 br->bridge_max_age = br->max_age = 20 * HZ; 380 br->bridge_hello_time = br->hello_time = 2 * HZ; 381 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 382 br->ageing_time = 300 * HZ; 383 384 br_netfilter_rtable_init(br); 385 br_stp_timer_init(br); 386 br_multicast_init(br); 387 } 388