| 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 | const struct nf_br_ops __rcu *nf_br_ops __read_mostly; |
| 29 | EXPORT_SYMBOL_GPL(nf_br_ops); |
| 30 | |
| 31 | static struct lock_class_key bridge_netdev_addr_lock_key; |
| 32 | |
| 33 | /* net device transmit always called with BH disabled */ |
| 34 | netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) |
| 35 | { |
| 36 | struct net_bridge *br = netdev_priv(dev); |
| 37 | const unsigned char *dest = skb->data; |
| 38 | struct net_bridge_fdb_entry *dst; |
| 39 | struct net_bridge_mdb_entry *mdst; |
| 40 | struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats); |
| 41 | const struct nf_br_ops *nf_ops; |
| 42 | u16 vid = 0; |
| 43 | |
| 44 | rcu_read_lock(); |
| 45 | nf_ops = rcu_dereference(nf_br_ops); |
| 46 | if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) { |
| 47 | rcu_read_unlock(); |
| 48 | return NETDEV_TX_OK; |
| 49 | } |
| 50 | |
| 51 | u64_stats_update_begin(&brstats->syncp); |
| 52 | brstats->tx_packets++; |
| 53 | brstats->tx_bytes += skb->len; |
| 54 | u64_stats_update_end(&brstats->syncp); |
| 55 | |
| 56 | BR_INPUT_SKB_CB(skb)->brdev = dev; |
| 57 | |
| 58 | skb_reset_mac_header(skb); |
| 59 | skb_pull(skb, ETH_HLEN); |
| 60 | |
| 61 | if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid)) |
| 62 | goto out; |
| 63 | |
| 64 | if (is_broadcast_ether_addr(dest)) |
| 65 | br_flood_deliver(br, skb, false); |
| 66 | else if (is_multicast_ether_addr(dest)) { |
| 67 | if (unlikely(netpoll_tx_running(dev))) { |
| 68 | br_flood_deliver(br, skb, false); |
| 69 | goto out; |
| 70 | } |
| 71 | if (br_multicast_rcv(br, NULL, skb, vid)) { |
| 72 | kfree_skb(skb); |
| 73 | goto out; |
| 74 | } |
| 75 | |
| 76 | mdst = br_mdb_get(br, skb, vid); |
| 77 | if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) && |
| 78 | br_multicast_querier_exists(br, eth_hdr(skb))) |
| 79 | br_multicast_deliver(mdst, skb); |
| 80 | else |
| 81 | br_flood_deliver(br, skb, false); |
| 82 | } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL) |
| 83 | br_deliver(dst->dst, skb); |
| 84 | else |
| 85 | br_flood_deliver(br, skb, true); |
| 86 | |
| 87 | out: |
| 88 | rcu_read_unlock(); |
| 89 | return NETDEV_TX_OK; |
| 90 | } |
| 91 | |
| 92 | static void br_set_lockdep_class(struct net_device *dev) |
| 93 | { |
| 94 | lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key); |
| 95 | } |
| 96 | |
| 97 | static int br_dev_init(struct net_device *dev) |
| 98 | { |
| 99 | struct net_bridge *br = netdev_priv(dev); |
| 100 | int err; |
| 101 | |
| 102 | br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats); |
| 103 | if (!br->stats) |
| 104 | return -ENOMEM; |
| 105 | |
| 106 | err = br_vlan_init(br); |
| 107 | if (err) |
| 108 | free_percpu(br->stats); |
| 109 | br_set_lockdep_class(dev); |
| 110 | |
| 111 | return err; |
| 112 | } |
| 113 | |
| 114 | static int br_dev_open(struct net_device *dev) |
| 115 | { |
| 116 | struct net_bridge *br = netdev_priv(dev); |
| 117 | |
| 118 | netdev_update_features(dev); |
| 119 | netif_start_queue(dev); |
| 120 | br_stp_enable_bridge(br); |
| 121 | br_multicast_open(br); |
| 122 | |
| 123 | return 0; |
| 124 | } |
| 125 | |
| 126 | static void br_dev_set_multicast_list(struct net_device *dev) |
| 127 | { |
| 128 | } |
| 129 | |
| 130 | static void br_dev_change_rx_flags(struct net_device *dev, int change) |
| 131 | { |
| 132 | if (change & IFF_PROMISC) |
| 133 | br_manage_promisc(netdev_priv(dev)); |
| 134 | } |
| 135 | |
| 136 | static int br_dev_stop(struct net_device *dev) |
| 137 | { |
| 138 | struct net_bridge *br = netdev_priv(dev); |
| 139 | |
| 140 | br_stp_disable_bridge(br); |
| 141 | br_multicast_stop(br); |
| 142 | |
| 143 | netif_stop_queue(dev); |
| 144 | |
| 145 | return 0; |
| 146 | } |
| 147 | |
| 148 | static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev, |
| 149 | struct rtnl_link_stats64 *stats) |
| 150 | { |
| 151 | struct net_bridge *br = netdev_priv(dev); |
| 152 | struct pcpu_sw_netstats tmp, sum = { 0 }; |
| 153 | unsigned int cpu; |
| 154 | |
| 155 | for_each_possible_cpu(cpu) { |
| 156 | unsigned int start; |
| 157 | const struct pcpu_sw_netstats *bstats |
| 158 | = per_cpu_ptr(br->stats, cpu); |
| 159 | do { |
| 160 | start = u64_stats_fetch_begin_irq(&bstats->syncp); |
| 161 | memcpy(&tmp, bstats, sizeof(tmp)); |
| 162 | } while (u64_stats_fetch_retry_irq(&bstats->syncp, start)); |
| 163 | sum.tx_bytes += tmp.tx_bytes; |
| 164 | sum.tx_packets += tmp.tx_packets; |
| 165 | sum.rx_bytes += tmp.rx_bytes; |
| 166 | sum.rx_packets += tmp.rx_packets; |
| 167 | } |
| 168 | |
| 169 | stats->tx_bytes = sum.tx_bytes; |
| 170 | stats->tx_packets = sum.tx_packets; |
| 171 | stats->rx_bytes = sum.rx_bytes; |
| 172 | stats->rx_packets = sum.rx_packets; |
| 173 | |
| 174 | return stats; |
| 175 | } |
| 176 | |
| 177 | static int br_change_mtu(struct net_device *dev, int new_mtu) |
| 178 | { |
| 179 | struct net_bridge *br = netdev_priv(dev); |
| 180 | if (new_mtu < 68 || new_mtu > br_min_mtu(br)) |
| 181 | return -EINVAL; |
| 182 | |
| 183 | dev->mtu = new_mtu; |
| 184 | |
| 185 | #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) |
| 186 | /* remember the MTU in the rtable for PMTU */ |
| 187 | dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu); |
| 188 | #endif |
| 189 | |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | /* Allow setting mac address to any valid ethernet address. */ |
| 194 | static int br_set_mac_address(struct net_device *dev, void *p) |
| 195 | { |
| 196 | struct net_bridge *br = netdev_priv(dev); |
| 197 | struct sockaddr *addr = p; |
| 198 | |
| 199 | if (!is_valid_ether_addr(addr->sa_data)) |
| 200 | return -EADDRNOTAVAIL; |
| 201 | |
| 202 | spin_lock_bh(&br->lock); |
| 203 | if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) { |
| 204 | /* Mac address will be changed in br_stp_change_bridge_id(). */ |
| 205 | br_stp_change_bridge_id(br, addr->sa_data); |
| 206 | } |
| 207 | spin_unlock_bh(&br->lock); |
| 208 | |
| 209 | return 0; |
| 210 | } |
| 211 | |
| 212 | static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info) |
| 213 | { |
| 214 | strlcpy(info->driver, "bridge", sizeof(info->driver)); |
| 215 | strlcpy(info->version, BR_VERSION, sizeof(info->version)); |
| 216 | strlcpy(info->fw_version, "N/A", sizeof(info->fw_version)); |
| 217 | strlcpy(info->bus_info, "N/A", sizeof(info->bus_info)); |
| 218 | } |
| 219 | |
| 220 | static netdev_features_t br_fix_features(struct net_device *dev, |
| 221 | netdev_features_t features) |
| 222 | { |
| 223 | struct net_bridge *br = netdev_priv(dev); |
| 224 | |
| 225 | return br_features_recompute(br, features); |
| 226 | } |
| 227 | |
| 228 | #ifdef CONFIG_NET_POLL_CONTROLLER |
| 229 | static void br_poll_controller(struct net_device *br_dev) |
| 230 | { |
| 231 | } |
| 232 | |
| 233 | static void br_netpoll_cleanup(struct net_device *dev) |
| 234 | { |
| 235 | struct net_bridge *br = netdev_priv(dev); |
| 236 | struct net_bridge_port *p; |
| 237 | |
| 238 | list_for_each_entry(p, &br->port_list, list) |
| 239 | br_netpoll_disable(p); |
| 240 | } |
| 241 | |
| 242 | static int __br_netpoll_enable(struct net_bridge_port *p) |
| 243 | { |
| 244 | struct netpoll *np; |
| 245 | int err; |
| 246 | |
| 247 | np = kzalloc(sizeof(*p->np), GFP_KERNEL); |
| 248 | if (!np) |
| 249 | return -ENOMEM; |
| 250 | |
| 251 | err = __netpoll_setup(np, p->dev); |
| 252 | if (err) { |
| 253 | kfree(np); |
| 254 | return err; |
| 255 | } |
| 256 | |
| 257 | p->np = np; |
| 258 | return err; |
| 259 | } |
| 260 | |
| 261 | int br_netpoll_enable(struct net_bridge_port *p) |
| 262 | { |
| 263 | if (!p->br->dev->npinfo) |
| 264 | return 0; |
| 265 | |
| 266 | return __br_netpoll_enable(p); |
| 267 | } |
| 268 | |
| 269 | static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni) |
| 270 | { |
| 271 | struct net_bridge *br = netdev_priv(dev); |
| 272 | struct net_bridge_port *p; |
| 273 | int err = 0; |
| 274 | |
| 275 | list_for_each_entry(p, &br->port_list, list) { |
| 276 | if (!p->dev) |
| 277 | continue; |
| 278 | err = __br_netpoll_enable(p); |
| 279 | if (err) |
| 280 | goto fail; |
| 281 | } |
| 282 | |
| 283 | out: |
| 284 | return err; |
| 285 | |
| 286 | fail: |
| 287 | br_netpoll_cleanup(dev); |
| 288 | goto out; |
| 289 | } |
| 290 | |
| 291 | void br_netpoll_disable(struct net_bridge_port *p) |
| 292 | { |
| 293 | struct netpoll *np = p->np; |
| 294 | |
| 295 | if (!np) |
| 296 | return; |
| 297 | |
| 298 | p->np = NULL; |
| 299 | |
| 300 | __netpoll_free_async(np); |
| 301 | } |
| 302 | |
| 303 | #endif |
| 304 | |
| 305 | static int br_add_slave(struct net_device *dev, struct net_device *slave_dev) |
| 306 | |
| 307 | { |
| 308 | struct net_bridge *br = netdev_priv(dev); |
| 309 | |
| 310 | return br_add_if(br, slave_dev); |
| 311 | } |
| 312 | |
| 313 | static int br_del_slave(struct net_device *dev, struct net_device *slave_dev) |
| 314 | { |
| 315 | struct net_bridge *br = netdev_priv(dev); |
| 316 | |
| 317 | return br_del_if(br, slave_dev); |
| 318 | } |
| 319 | |
| 320 | static const struct ethtool_ops br_ethtool_ops = { |
| 321 | .get_drvinfo = br_getinfo, |
| 322 | .get_link = ethtool_op_get_link, |
| 323 | }; |
| 324 | |
| 325 | static const struct net_device_ops br_netdev_ops = { |
| 326 | .ndo_open = br_dev_open, |
| 327 | .ndo_stop = br_dev_stop, |
| 328 | .ndo_init = br_dev_init, |
| 329 | .ndo_start_xmit = br_dev_xmit, |
| 330 | .ndo_get_stats64 = br_get_stats64, |
| 331 | .ndo_set_mac_address = br_set_mac_address, |
| 332 | .ndo_set_rx_mode = br_dev_set_multicast_list, |
| 333 | .ndo_change_rx_flags = br_dev_change_rx_flags, |
| 334 | .ndo_change_mtu = br_change_mtu, |
| 335 | .ndo_do_ioctl = br_dev_ioctl, |
| 336 | #ifdef CONFIG_NET_POLL_CONTROLLER |
| 337 | .ndo_netpoll_setup = br_netpoll_setup, |
| 338 | .ndo_netpoll_cleanup = br_netpoll_cleanup, |
| 339 | .ndo_poll_controller = br_poll_controller, |
| 340 | #endif |
| 341 | .ndo_add_slave = br_add_slave, |
| 342 | .ndo_del_slave = br_del_slave, |
| 343 | .ndo_fix_features = br_fix_features, |
| 344 | .ndo_fdb_add = br_fdb_add, |
| 345 | .ndo_fdb_del = br_fdb_delete, |
| 346 | .ndo_fdb_dump = br_fdb_dump, |
| 347 | .ndo_bridge_getlink = br_getlink, |
| 348 | .ndo_bridge_setlink = br_setlink, |
| 349 | .ndo_bridge_dellink = br_dellink, |
| 350 | .ndo_features_check = passthru_features_check, |
| 351 | }; |
| 352 | |
| 353 | static void br_dev_free(struct net_device *dev) |
| 354 | { |
| 355 | struct net_bridge *br = netdev_priv(dev); |
| 356 | |
| 357 | free_percpu(br->stats); |
| 358 | free_netdev(dev); |
| 359 | } |
| 360 | |
| 361 | static struct device_type br_type = { |
| 362 | .name = "bridge", |
| 363 | }; |
| 364 | |
| 365 | void br_dev_setup(struct net_device *dev) |
| 366 | { |
| 367 | struct net_bridge *br = netdev_priv(dev); |
| 368 | |
| 369 | eth_hw_addr_random(dev); |
| 370 | ether_setup(dev); |
| 371 | |
| 372 | dev->netdev_ops = &br_netdev_ops; |
| 373 | dev->destructor = br_dev_free; |
| 374 | dev->ethtool_ops = &br_ethtool_ops; |
| 375 | SET_NETDEV_DEVTYPE(dev, &br_type); |
| 376 | dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE; |
| 377 | |
| 378 | dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL | |
| 379 | NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; |
| 380 | dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | |
| 381 | NETIF_F_HW_VLAN_STAG_TX; |
| 382 | dev->vlan_features = COMMON_FEATURES; |
| 383 | |
| 384 | br->dev = dev; |
| 385 | spin_lock_init(&br->lock); |
| 386 | INIT_LIST_HEAD(&br->port_list); |
| 387 | spin_lock_init(&br->hash_lock); |
| 388 | |
| 389 | br->bridge_id.prio[0] = 0x80; |
| 390 | br->bridge_id.prio[1] = 0x00; |
| 391 | |
| 392 | ether_addr_copy(br->group_addr, eth_reserved_addr_base); |
| 393 | |
| 394 | br->stp_enabled = BR_NO_STP; |
| 395 | br->group_fwd_mask = BR_GROUPFWD_DEFAULT; |
| 396 | br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT; |
| 397 | |
| 398 | br->designated_root = br->bridge_id; |
| 399 | br->bridge_max_age = br->max_age = 20 * HZ; |
| 400 | br->bridge_hello_time = br->hello_time = 2 * HZ; |
| 401 | br->bridge_forward_delay = br->forward_delay = 15 * HZ; |
| 402 | br->ageing_time = BR_DEFAULT_AGEING_TIME; |
| 403 | |
| 404 | br_netfilter_rtable_init(br); |
| 405 | br_stp_timer_init(br); |
| 406 | br_multicast_init(br); |
| 407 | } |