net/bridge/br_device.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Device handling code
   4  *      Linux ethernet bridge
   5  *
   6  *      Authors:
   7  *      Lennert Buytenhek               <buytenh@gnu.org>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/netdevice.h>
  12 #include <linux/netpoll.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/ethtool.h>
  15 #include <linux/list.h>
  16 #include <linux/netfilter_bridge.h>
  17
  18 #include <linux/uaccess.h>
  19 #include "br_private.h"
  20
  21 #define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \
  22                          NETIF_F_GSO_MASK | NETIF_F_HW_CSUM)
  23
  24 const struct nf_br_ops __rcu *nf_br_ops __read_mostly;
  25 EXPORT_SYMBOL_GPL(nf_br_ops);
  26
  27 /* net device transmit always called with BH disabled */
  28 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
  29 {
  30         struct net_bridge *br = netdev_priv(dev);
  31         struct net_bridge_fdb_entry *dst;
  32         struct net_bridge_mdb_entry *mdst;
  33         struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);
  34         const struct nf_br_ops *nf_ops;
  35         u8 state = BR_STATE_FORWARDING;
  36         const unsigned char *dest;
  37         u16 vid = 0;
  38
  39         rcu_read_lock();
  40         nf_ops = rcu_dereference(nf_br_ops);
  41         if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
  42                 rcu_read_unlock();
  43                 return NETDEV_TX_OK;
  44         }
  45
  46         u64_stats_update_begin(&brstats->syncp);
  47         brstats->tx_packets++;
  48         brstats->tx_bytes += skb->len;
  49         u64_stats_update_end(&brstats->syncp);
  50
  51         br_switchdev_frame_unmark(skb);
  52         BR_INPUT_SKB_CB(skb)->brdev = dev;
  53         BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
  54
  55         skb_reset_mac_header(skb);
  56         skb_pull(skb, ETH_HLEN);
  57
  58         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid, &state))
  59                 goto out;
  60
  61         if (IS_ENABLED(CONFIG_INET) &&
  62             (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) ||
  63              eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) &&
  64             br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
  65                 br_do_proxy_suppress_arp(skb, br, vid, NULL);
  66         } else if (IS_ENABLED(CONFIG_IPV6) &&
  67                    skb->protocol == htons(ETH_P_IPV6) &&
  68                    br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
  69                    pskb_may_pull(skb, sizeof(struct ipv6hdr) +
  70                                  sizeof(struct nd_msg)) &&
  71                    ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
  72                         struct nd_msg *msg, _msg;
  73
  74                         msg = br_is_nd_neigh_msg(skb, &_msg);
  75                         if (msg)
  76                                 br_do_suppress_nd(skb, br, vid, NULL, msg);
  77         }
  78
  79         dest = eth_hdr(skb)->h_dest;
  80         if (is_broadcast_ether_addr(dest)) {
  81                 br_flood(br, skb, BR_PKT_BROADCAST, false, true);
  82         } else if (is_multicast_ether_addr(dest)) {
  83                 if (unlikely(netpoll_tx_running(dev))) {
  84                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  85                         goto out;
  86                 }
  87                 if (br_multicast_rcv(br, NULL, skb, vid)) {
  88                         kfree_skb(skb);
  89                         goto out;
  90                 }
  91
  92                 mdst = br_mdb_get(br, skb, vid);
  93                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
  94                     br_multicast_querier_exists(br, eth_hdr(skb)))
  95                         br_multicast_flood(mdst, skb, false, true);
  96                 else
  97                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  98         } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
  99                 br_forward(dst->dst, skb, false, true);
 100         } else {
 101                 br_flood(br, skb, BR_PKT_UNICAST, false, true);
 102         }
 103 out:
 104         rcu_read_unlock();
 105         return NETDEV_TX_OK;
 106 }
 107
 108 static struct lock_class_key bridge_netdev_addr_lock_key;
 109
 110 static void br_set_lockdep_class(struct net_device *dev)
 111 {
 112         lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key);
 113 }
 114
 115 static int br_dev_init(struct net_device *dev)
 116 {
 117         struct net_bridge *br = netdev_priv(dev);
 118         int err;
 119
 120         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 121         if (!br->stats)
 122                 return -ENOMEM;
 123
 124         err = br_fdb_hash_init(br);
 125         if (err) {
 126                 free_percpu(br->stats);
 127                 return err;
 128         }
 129
 130         err = br_mdb_hash_init(br);
 131         if (err) {
 132                 free_percpu(br->stats);
 133                 br_fdb_hash_fini(br);
 134                 return err;
 135         }
 136
 137         err = br_vlan_init(br);
 138         if (err) {
 139                 free_percpu(br->stats);
 140                 br_mdb_hash_fini(br);
 141                 br_fdb_hash_fini(br);
 142                 return err;
 143         }
 144
 145         err = br_multicast_init_stats(br);
 146         if (err) {
 147                 free_percpu(br->stats);
 148                 br_vlan_flush(br);
 149                 br_mdb_hash_fini(br);
 150                 br_fdb_hash_fini(br);
 151         }
 152
 153         br_set_lockdep_class(dev);
 154         return err;
 155 }
 156
 157 static void br_dev_uninit(struct net_device *dev)
 158 {
 159         struct net_bridge *br = netdev_priv(dev);
 160
 161         br_multicast_dev_del(br);
 162         br_multicast_uninit_stats(br);
 163         br_vlan_flush(br);
 164         br_mdb_hash_fini(br);
 165         br_fdb_hash_fini(br);
 166         free_percpu(br->stats);
 167 }
 168
 169 static int br_dev_open(struct net_device *dev)
 170 {
 171         struct net_bridge *br = netdev_priv(dev);
 172
 173         netdev_update_features(dev);
 174         netif_start_queue(dev);
 175         br_stp_enable_bridge(br);
 176         br_multicast_open(br);
 177
 178         return 0;
 179 }
 180
 181 static void br_dev_set_multicast_list(struct net_device *dev)
 182 {
 183 }
 184
 185 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 186 {
 187         if (change & IFF_PROMISC)
 188                 br_manage_promisc(netdev_priv(dev));
 189 }
 190
 191 static int br_dev_stop(struct net_device *dev)
 192 {
 193         struct net_bridge *br = netdev_priv(dev);
 194
 195         br_stp_disable_bridge(br);
 196         br_multicast_stop(br);
 197
 198         netif_stop_queue(dev);
 199
 200         return 0;
 201 }
 202
 203 static void br_get_stats64(struct net_device *dev,
 204                            struct rtnl_link_stats64 *stats)
 205 {
 206         struct net_bridge *br = netdev_priv(dev);
 207         struct pcpu_sw_netstats tmp, sum = { 0 };
 208         unsigned int cpu;
 209
 210         for_each_possible_cpu(cpu) {
 211                 unsigned int start;
 212                 const struct pcpu_sw_netstats *bstats
 213                         = per_cpu_ptr(br->stats, cpu);
 214                 do {
 215                         start = u64_stats_fetch_begin_irq(&bstats->syncp);
 216                         memcpy(&tmp, bstats, sizeof(tmp));
 217                 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
 218                 sum.tx_bytes   += tmp.tx_bytes;
 219                 sum.tx_packets += tmp.tx_packets;
 220                 sum.rx_bytes   += tmp.rx_bytes;
 221                 sum.rx_packets += tmp.rx_packets;
 222         }
 223
 224         stats->tx_bytes   = sum.tx_bytes;
 225         stats->tx_packets = sum.tx_packets;
 226         stats->rx_bytes   = sum.rx_bytes;
 227         stats->rx_packets = sum.rx_packets;
 228 }
 229
 230 static int br_change_mtu(struct net_device *dev, int new_mtu)
 231 {
 232         struct net_bridge *br = netdev_priv(dev);
 233
 234         dev->mtu = new_mtu;
 235
 236         /* this flag will be cleared if the MTU was automatically adjusted */
 237         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 238 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 239         /* remember the MTU in the rtable for PMTU */
 240         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 241 #endif
 242
 243         return 0;
 244 }
 245
 246 /* Allow setting mac address to any valid ethernet address. */
 247 static int br_set_mac_address(struct net_device *dev, void *p)
 248 {
 249         struct net_bridge *br = netdev_priv(dev);
 250         struct sockaddr *addr = p;
 251
 252         if (!is_valid_ether_addr(addr->sa_data))
 253                 return -EADDRNOTAVAIL;
 254
 255         /* dev_set_mac_addr() can be called by a master device on bridge's
 256          * NETDEV_UNREGISTER, but since it's being destroyed do nothing
 257          */
 258         if (dev->reg_state != NETREG_REGISTERED)
 259                 return -EBUSY;
 260
 261         spin_lock_bh(&br->lock);
 262         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 263                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 264                 br_stp_change_bridge_id(br, addr->sa_data);
 265         }
 266         spin_unlock_bh(&br->lock);
 267
 268         return 0;
 269 }
 270
 271 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 272 {
 273         strlcpy(info->driver, "bridge", sizeof(info->driver));
 274         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 275         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 276         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 277 }
 278
 279 static int br_get_link_ksettings(struct net_device *dev,
 280                                  struct ethtool_link_ksettings *cmd)
 281 {
 282         struct net_bridge *br = netdev_priv(dev);
 283         struct net_bridge_port *p;
 284
 285         cmd->base.duplex = DUPLEX_UNKNOWN;
 286         cmd->base.port = PORT_OTHER;
 287         cmd->base.speed = SPEED_UNKNOWN;
 288
 289         list_for_each_entry(p, &br->port_list, list) {
 290                 struct ethtool_link_ksettings ecmd;
 291                 struct net_device *pdev = p->dev;
 292
 293                 if (!netif_running(pdev) || !netif_oper_up(pdev))
 294                         continue;
 295
 296                 if (__ethtool_get_link_ksettings(pdev, &ecmd))
 297                         continue;
 298
 299                 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
 300                         continue;
 301
 302                 if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
 303                     cmd->base.speed < ecmd.base.speed)
 304                         cmd->base.speed = ecmd.base.speed;
 305         }
 306
 307         return 0;
 308 }
 309
 310 static netdev_features_t br_fix_features(struct net_device *dev,
 311         netdev_features_t features)
 312 {
 313         struct net_bridge *br = netdev_priv(dev);
 314
 315         return br_features_recompute(br, features);
 316 }
 317
 318 #ifdef CONFIG_NET_POLL_CONTROLLER
 319 static void br_poll_controller(struct net_device *br_dev)
 320 {
 321 }
 322
 323 static void br_netpoll_cleanup(struct net_device *dev)
 324 {
 325         struct net_bridge *br = netdev_priv(dev);
 326         struct net_bridge_port *p;
 327
 328         list_for_each_entry(p, &br->port_list, list)
 329                 br_netpoll_disable(p);
 330 }
 331
 332 static int __br_netpoll_enable(struct net_bridge_port *p)
 333 {
 334         struct netpoll *np;
 335         int err;
 336
 337         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 338         if (!np)
 339                 return -ENOMEM;
 340
 341         err = __netpoll_setup(np, p->dev);
 342         if (err) {
 343                 kfree(np);
 344                 return err;
 345         }
 346
 347         p->np = np;
 348         return err;
 349 }
 350
 351 int br_netpoll_enable(struct net_bridge_port *p)
 352 {
 353         if (!p->br->dev->npinfo)
 354                 return 0;
 355
 356         return __br_netpoll_enable(p);
 357 }
 358
 359 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 360 {
 361         struct net_bridge *br = netdev_priv(dev);
 362         struct net_bridge_port *p;
 363         int err = 0;
 364
 365         list_for_each_entry(p, &br->port_list, list) {
 366                 if (!p->dev)
 367                         continue;
 368                 err = __br_netpoll_enable(p);
 369                 if (err)
 370                         goto fail;
 371         }
 372
 373 out:
 374         return err;
 375
 376 fail:
 377         br_netpoll_cleanup(dev);
 378         goto out;
 379 }
 380
 381 void br_netpoll_disable(struct net_bridge_port *p)
 382 {
 383         struct netpoll *np = p->np;
 384
 385         if (!np)
 386                 return;
 387
 388         p->np = NULL;
 389
 390         __netpoll_free(np);
 391 }
 392
 393 #endif
 394
 395 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 396                         struct netlink_ext_ack *extack)
 397
 398 {
 399         struct net_bridge *br = netdev_priv(dev);
 400
 401         return br_add_if(br, slave_dev, extack);
 402 }
 403
 404 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 405 {
 406         struct net_bridge *br = netdev_priv(dev);
 407
 408         return br_del_if(br, slave_dev);
 409 }
 410
 411 static const struct ethtool_ops br_ethtool_ops = {
 412         .get_drvinfo             = br_getinfo,
 413         .get_link                = ethtool_op_get_link,
 414         .get_link_ksettings      = br_get_link_ksettings,
 415 };
 416
 417 static const struct net_device_ops br_netdev_ops = {
 418         .ndo_open                = br_dev_open,
 419         .ndo_stop                = br_dev_stop,
 420         .ndo_init                = br_dev_init,
 421         .ndo_uninit              = br_dev_uninit,
 422         .ndo_start_xmit          = br_dev_xmit,
 423         .ndo_get_stats64         = br_get_stats64,
 424         .ndo_set_mac_address     = br_set_mac_address,
 425         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 426         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 427         .ndo_change_mtu          = br_change_mtu,
 428         .ndo_do_ioctl            = br_dev_ioctl,
 429 #ifdef CONFIG_NET_POLL_CONTROLLER
 430         .ndo_netpoll_setup       = br_netpoll_setup,
 431         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 432         .ndo_poll_controller     = br_poll_controller,
 433 #endif
 434         .ndo_add_slave           = br_add_slave,
 435         .ndo_del_slave           = br_del_slave,
 436         .ndo_fix_features        = br_fix_features,
 437         .ndo_fdb_add             = br_fdb_add,
 438         .ndo_fdb_del             = br_fdb_delete,
 439         .ndo_fdb_dump            = br_fdb_dump,
 440         .ndo_fdb_get             = br_fdb_get,
 441         .ndo_bridge_getlink      = br_getlink,
 442         .ndo_bridge_setlink      = br_setlink,
 443         .ndo_bridge_dellink      = br_dellink,
 444         .ndo_features_check      = passthru_features_check,
 445 };
 446
 447 static struct device_type br_type = {
 448         .name   = "bridge",
 449 };
 450
 451 void br_dev_setup(struct net_device *dev)
 452 {
 453         struct net_bridge *br = netdev_priv(dev);
 454
 455         eth_hw_addr_random(dev);
 456         ether_setup(dev);
 457
 458         dev->netdev_ops = &br_netdev_ops;
 459         dev->needs_free_netdev = true;
 460         dev->ethtool_ops = &br_ethtool_ops;
 461         SET_NETDEV_DEVTYPE(dev, &br_type);
 462         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 463
 464         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 465                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 466         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 467                            NETIF_F_HW_VLAN_STAG_TX;
 468         dev->vlan_features = COMMON_FEATURES;
 469
 470         br->dev = dev;
 471         spin_lock_init(&br->lock);
 472         INIT_LIST_HEAD(&br->port_list);
 473         INIT_HLIST_HEAD(&br->fdb_list);
 474 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 475         INIT_LIST_HEAD(&br->mrp_list);
 476 #endif
 477         spin_lock_init(&br->hash_lock);
 478
 479         br->bridge_id.prio[0] = 0x80;
 480         br->bridge_id.prio[1] = 0x00;
 481
 482         ether_addr_copy(br->group_addr, eth_stp_addr);
 483
 484         br->stp_enabled = BR_NO_STP;
 485         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 486         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 487
 488         br->designated_root = br->bridge_id;
 489         br->bridge_max_age = br->max_age = 20 * HZ;
 490         br->bridge_hello_time = br->hello_time = 2 * HZ;
 491         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 492         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 493         dev->max_mtu = ETH_MAX_MTU;
 494
 495         br_netfilter_rtable_init(br);
 496         br_stp_timer_init(br);
 497         br_multicast_init(br);
 498         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 499 }