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_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 92 br->stats = alloc_percpu(struct br_cpu_netstats); 93 if (!br->stats) 94 return -ENOMEM; 95 96 return 0; 97 } 98 99 static int br_dev_open(struct net_device *dev) 100 { 101 struct net_bridge *br = netdev_priv(dev); 102 103 netdev_update_features(dev); 104 netif_start_queue(dev); 105 br_stp_enable_bridge(br); 106 br_multicast_open(br); 107 108 return 0; 109 } 110 111 static void br_dev_set_multicast_list(struct net_device *dev) 112 { 113 } 114 115 static int br_dev_stop(struct net_device *dev) 116 { 117 struct net_bridge *br = netdev_priv(dev); 118 119 br_stp_disable_bridge(br); 120 br_multicast_stop(br); 121 122 netif_stop_queue(dev); 123 124 return 0; 125 } 126 127 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, 128 struct rtnl_link_stats64 *stats) 129 { 130 struct net_bridge *br = netdev_priv(dev); 131 struct br_cpu_netstats tmp, sum = { 0 }; 132 unsigned int cpu; 133 134 for_each_possible_cpu(cpu) { 135 unsigned int start; 136 const struct br_cpu_netstats *bstats 137 = per_cpu_ptr(br->stats, cpu); 138 do { 139 start = u64_stats_fetch_begin_bh(&bstats->syncp); 140 memcpy(&tmp, bstats, sizeof(tmp)); 141 } while (u64_stats_fetch_retry_bh(&bstats->syncp, start)); 142 sum.tx_bytes += tmp.tx_bytes; 143 sum.tx_packets += tmp.tx_packets; 144 sum.rx_bytes += tmp.rx_bytes; 145 sum.rx_packets += tmp.rx_packets; 146 } 147 148 stats->tx_bytes = sum.tx_bytes; 149 stats->tx_packets = sum.tx_packets; 150 stats->rx_bytes = sum.rx_bytes; 151 stats->rx_packets = sum.rx_packets; 152 153 return stats; 154 } 155 156 static int br_change_mtu(struct net_device *dev, int new_mtu) 157 { 158 struct net_bridge *br = netdev_priv(dev); 159 if (new_mtu < 68 || new_mtu > br_min_mtu(br)) 160 return -EINVAL; 161 162 dev->mtu = new_mtu; 163 164 #ifdef CONFIG_BRIDGE_NETFILTER 165 /* remember the MTU in the rtable for PMTU */ 166 dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); 167 #endif 168 169 return 0; 170 } 171 172 /* Allow setting mac address to any valid ethernet address. */ 173 static int br_set_mac_address(struct net_device *dev, void *p) 174 { 175 struct net_bridge *br = netdev_priv(dev); 176 struct sockaddr *addr = p; 177 178 if (!is_valid_ether_addr(addr->sa_data)) 179 return -EADDRNOTAVAIL; 180 181 spin_lock_bh(&br->lock); 182 if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { 183 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN); 184 br_fdb_change_mac_address(br, addr->sa_data); 185 br_stp_change_bridge_id(br, addr->sa_data); 186 } 187 spin_unlock_bh(&br->lock); 188 189 return 0; 190 } 191 192 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) 193 { 194 strlcpy(info->driver, "bridge", sizeof(info->driver)); 195 strlcpy(info->version, BR_VERSION, sizeof(info->version)); 196 strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); 197 strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); 198 } 199 200 static netdev_features_t br_fix_features(struct net_device *dev, 201 netdev_features_t features) 202 { 203 struct net_bridge *br = netdev_priv(dev); 204 205 return br_features_recompute(br, features); 206 } 207 208 #ifdef CONFIG_NET_POLL_CONTROLLER 209 static void br_poll_controller(struct net_device *br_dev) 210 { 211 } 212 213 static void br_netpoll_cleanup(struct net_device *dev) 214 { 215 struct net_bridge *br = netdev_priv(dev); 216 struct net_bridge_port *p; 217 218 list_for_each_entry(p, &br->port_list, list) 219 br_netpoll_disable(p); 220 } 221 222 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni, 223 gfp_t gfp) 224 { 225 struct net_bridge *br = netdev_priv(dev); 226 struct net_bridge_port *p; 227 int err = 0; 228 229 list_for_each_entry(p, &br->port_list, list) { 230 if (!p->dev) 231 continue; 232 err = br_netpoll_enable(p, gfp); 233 if (err) 234 goto fail; 235 } 236 237 out: 238 return err; 239 240 fail: 241 br_netpoll_cleanup(dev); 242 goto out; 243 } 244 245 int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp) 246 { 247 struct netpoll *np; 248 int err = 0; 249 250 np = kzalloc(sizeof(*p->np), gfp); 251 err = -ENOMEM; 252 if (!np) 253 goto out; 254 255 err = __netpoll_setup(np, p->dev, gfp); 256 if (err) { 257 kfree(np); 258 goto out; 259 } 260 261 p->np = np; 262 263 out: 264 return err; 265 } 266 267 void br_netpoll_disable(struct net_bridge_port *p) 268 { 269 struct netpoll *np = p->np; 270 271 if (!np) 272 return; 273 274 p->np = NULL; 275 276 __netpoll_free_async(np); 277 } 278 279 #endif 280 281 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) 282 283 { 284 struct net_bridge *br = netdev_priv(dev); 285 286 return br_add_if(br, slave_dev); 287 } 288 289 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) 290 { 291 struct net_bridge *br = netdev_priv(dev); 292 293 return br_del_if(br, slave_dev); 294 } 295 296 static const struct ethtool_ops br_ethtool_ops = { 297 .get_drvinfo = br_getinfo, 298 .get_link = ethtool_op_get_link, 299 }; 300 301 static const struct net_device_ops br_netdev_ops = { 302 .ndo_open = br_dev_open, 303 .ndo_stop = br_dev_stop, 304 .ndo_init = br_dev_init, 305 .ndo_start_xmit = br_dev_xmit, 306 .ndo_get_stats64 = br_get_stats64, 307 .ndo_set_mac_address = br_set_mac_address, 308 .ndo_set_rx_mode = br_dev_set_multicast_list, 309 .ndo_change_mtu = br_change_mtu, 310 .ndo_do_ioctl = br_dev_ioctl, 311 #ifdef CONFIG_NET_POLL_CONTROLLER 312 .ndo_netpoll_setup = br_netpoll_setup, 313 .ndo_netpoll_cleanup = br_netpoll_cleanup, 314 .ndo_poll_controller = br_poll_controller, 315 #endif 316 .ndo_add_slave = br_add_slave, 317 .ndo_del_slave = br_del_slave, 318 .ndo_fix_features = br_fix_features, 319 .ndo_fdb_add = br_fdb_add, 320 .ndo_fdb_del = br_fdb_delete, 321 .ndo_fdb_dump = br_fdb_dump, 322 .ndo_bridge_getlink = br_getlink, 323 .ndo_bridge_setlink = br_setlink, 324 .ndo_bridge_dellink = br_dellink, 325 }; 326 327 static void br_dev_free(struct net_device *dev) 328 { 329 struct net_bridge *br = netdev_priv(dev); 330 331 free_percpu(br->stats); 332 free_netdev(dev); 333 } 334 335 static struct device_type br_type = { 336 .name = "bridge", 337 }; 338 339 void br_dev_setup(struct net_device *dev) 340 { 341 struct net_bridge *br = netdev_priv(dev); 342 343 eth_hw_addr_random(dev); 344 ether_setup(dev); 345 346 dev->netdev_ops = &br_netdev_ops; 347 dev->destructor = br_dev_free; 348 SET_ETHTOOL_OPS(dev, &br_ethtool_ops); 349 SET_NETDEV_DEVTYPE(dev, &br_type); 350 dev->tx_queue_len = 0; 351 dev->priv_flags = IFF_EBRIDGE; 352 353 dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | 354 NETIF_F_HW_VLAN_CTAG_TX; 355 dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX; 356 dev->vlan_features = COMMON_FEATURES; 357 358 br->dev = dev; 359 spin_lock_init(&br->lock); 360 INIT_LIST_HEAD(&br->port_list); 361 spin_lock_init(&br->hash_lock); 362 363 br->bridge_id.prio[0] = 0x80; 364 br->bridge_id.prio[1] = 0x00; 365 366 memcpy(br->group_addr, eth_reserved_addr_base, ETH_ALEN); 367 368 br->stp_enabled = BR_NO_STP; 369 br->group_fwd_mask = BR_GROUPFWD_DEFAULT; 370 371 br->designated_root = br->bridge_id; 372 br->bridge_max_age = br->max_age = 20 * HZ; 373 br->bridge_hello_time = br->hello_time = 2 * HZ; 374 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 375 br->ageing_time = 300 * HZ; 376 377 br_netfilter_rtable_init(br); 378 br_stp_timer_init(br); 379 br_multicast_init(br); 380 } 381