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