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_mcast_port *pmctx_null = NULL;
  31         struct net_bridge *br = netdev_priv(dev);
  32         struct net_bridge_mcast *brmctx = &br->multicast_ctx;
  33         struct net_bridge_fdb_entry *dst;
  34         struct net_bridge_mdb_entry *mdst;
  35         const struct nf_br_ops *nf_ops;
  36         u8 state = BR_STATE_FORWARDING;
  37         struct net_bridge_vlan *vlan;
  38         const unsigned char *dest;
  39         u16 vid = 0;
  40
  41         memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
  42         br_tc_skb_miss_set(skb, false);
  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         dev_sw_netstats_tx_add(dev, 1, skb->len);
  52
  53         br_switchdev_frame_unmark(skb);
  54         BR_INPUT_SKB_CB(skb)->brdev = dev;
  55         BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
  56
  57         skb_reset_mac_header(skb);
  58         skb_pull(skb, ETH_HLEN);
  59
  60         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid,
  61                                 &state, &vlan))
  62                 goto out;
  63
  64         if (IS_ENABLED(CONFIG_INET) &&
  65             (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) ||
  66              eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) &&
  67             br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
  68                 br_do_proxy_suppress_arp(skb, br, vid, NULL);
  69         } else if (IS_ENABLED(CONFIG_IPV6) &&
  70                    skb->protocol == htons(ETH_P_IPV6) &&
  71                    br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
  72                    pskb_may_pull(skb, sizeof(struct ipv6hdr) +
  73                                  sizeof(struct nd_msg)) &&
  74                    ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
  75                         struct nd_msg *msg, _msg;
  76
  77                         msg = br_is_nd_neigh_msg(skb, &_msg);
  78                         if (msg)
  79                                 br_do_suppress_nd(skb, br, vid, NULL, msg);
  80         }
  81
  82         dest = eth_hdr(skb)->h_dest;
  83         if (is_broadcast_ether_addr(dest)) {
  84                 br_flood(br, skb, BR_PKT_BROADCAST, false, true, vid);
  85         } else if (is_multicast_ether_addr(dest)) {
  86                 if (unlikely(netpoll_tx_running(dev))) {
  87                         br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid);
  88                         goto out;
  89                 }
  90                 if (br_multicast_rcv(&brmctx, &pmctx_null, vlan, skb, vid)) {
  91                         kfree_skb(skb);
  92                         goto out;
  93                 }
  94
  95                 mdst = br_mdb_entry_skb_get(brmctx, skb, vid);
  96                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
  97                     br_multicast_querier_exists(brmctx, eth_hdr(skb), mdst))
  98                         br_multicast_flood(mdst, skb, brmctx, false, true);
  99                 else
 100                         br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid);
 101         } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
 102                 br_forward(dst->dst, skb, false, true);
 103         } else {
 104                 br_flood(br, skb, BR_PKT_UNICAST, false, true, vid);
 105         }
 106 out:
 107         rcu_read_unlock();
 108         return NETDEV_TX_OK;
 109 }
 110
 111 static int br_dev_init(struct net_device *dev)
 112 {
 113         struct net_bridge *br = netdev_priv(dev);
 114         int err;
 115
 116         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 117         if (!dev->tstats)
 118                 return -ENOMEM;
 119
 120         err = br_fdb_hash_init(br);
 121         if (err) {
 122                 free_percpu(dev->tstats);
 123                 return err;
 124         }
 125
 126         err = br_mdb_hash_init(br);
 127         if (err) {
 128                 free_percpu(dev->tstats);
 129                 br_fdb_hash_fini(br);
 130                 return err;
 131         }
 132
 133         err = br_vlan_init(br);
 134         if (err) {
 135                 free_percpu(dev->tstats);
 136                 br_mdb_hash_fini(br);
 137                 br_fdb_hash_fini(br);
 138                 return err;
 139         }
 140
 141         err = br_multicast_init_stats(br);
 142         if (err) {
 143                 free_percpu(dev->tstats);
 144                 br_vlan_flush(br);
 145                 br_mdb_hash_fini(br);
 146                 br_fdb_hash_fini(br);
 147         }
 148
 149         netdev_lockdep_set_classes(dev);
 150         return err;
 151 }
 152
 153 static void br_dev_uninit(struct net_device *dev)
 154 {
 155         struct net_bridge *br = netdev_priv(dev);
 156
 157         br_multicast_dev_del(br);
 158         br_multicast_uninit_stats(br);
 159         br_vlan_flush(br);
 160         br_mdb_hash_fini(br);
 161         br_fdb_hash_fini(br);
 162         free_percpu(dev->tstats);
 163 }
 164
 165 static int br_dev_open(struct net_device *dev)
 166 {
 167         struct net_bridge *br = netdev_priv(dev);
 168
 169         netdev_update_features(dev);
 170         netif_start_queue(dev);
 171         br_stp_enable_bridge(br);
 172         br_multicast_open(br);
 173
 174         if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 175                 br_multicast_join_snoopers(br);
 176
 177         return 0;
 178 }
 179
 180 static void br_dev_set_multicast_list(struct net_device *dev)
 181 {
 182 }
 183
 184 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 185 {
 186         if (change & IFF_PROMISC)
 187                 br_manage_promisc(netdev_priv(dev));
 188 }
 189
 190 static int br_dev_stop(struct net_device *dev)
 191 {
 192         struct net_bridge *br = netdev_priv(dev);
 193
 194         br_stp_disable_bridge(br);
 195         br_multicast_stop(br);
 196
 197         if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 198                 br_multicast_leave_snoopers(br);
 199
 200         netif_stop_queue(dev);
 201
 202         return 0;
 203 }
 204
 205 static int br_change_mtu(struct net_device *dev, int new_mtu)
 206 {
 207         struct net_bridge *br = netdev_priv(dev);
 208
 209         dev->mtu = new_mtu;
 210
 211         /* this flag will be cleared if the MTU was automatically adjusted */
 212         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 213 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 214         /* remember the MTU in the rtable for PMTU */
 215         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 216 #endif
 217
 218         return 0;
 219 }
 220
 221 /* Allow setting mac address to any valid ethernet address. */
 222 static int br_set_mac_address(struct net_device *dev, void *p)
 223 {
 224         struct net_bridge *br = netdev_priv(dev);
 225         struct sockaddr *addr = p;
 226
 227         if (!is_valid_ether_addr(addr->sa_data))
 228                 return -EADDRNOTAVAIL;
 229
 230         /* dev_set_mac_addr() can be called by a master device on bridge's
 231          * NETDEV_UNREGISTER, but since it's being destroyed do nothing
 232          */
 233         if (dev->reg_state != NETREG_REGISTERED)
 234                 return -EBUSY;
 235
 236         spin_lock_bh(&br->lock);
 237         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 238                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 239                 br_stp_change_bridge_id(br, addr->sa_data);
 240         }
 241         spin_unlock_bh(&br->lock);
 242
 243         return 0;
 244 }
 245
 246 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 247 {
 248         strscpy(info->driver, "bridge", sizeof(info->driver));
 249         strscpy(info->version, BR_VERSION, sizeof(info->version));
 250         strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
 251         strscpy(info->bus_info, "N/A", sizeof(info->bus_info));
 252 }
 253
 254 static int br_get_link_ksettings(struct net_device *dev,
 255                                  struct ethtool_link_ksettings *cmd)
 256 {
 257         struct net_bridge *br = netdev_priv(dev);
 258         struct net_bridge_port *p;
 259
 260         cmd->base.duplex = DUPLEX_UNKNOWN;
 261         cmd->base.port = PORT_OTHER;
 262         cmd->base.speed = SPEED_UNKNOWN;
 263
 264         list_for_each_entry(p, &br->port_list, list) {
 265                 struct ethtool_link_ksettings ecmd;
 266                 struct net_device *pdev = p->dev;
 267
 268                 if (!netif_running(pdev) || !netif_oper_up(pdev))
 269                         continue;
 270
 271                 if (__ethtool_get_link_ksettings(pdev, &ecmd))
 272                         continue;
 273
 274                 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
 275                         continue;
 276
 277                 if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
 278                     cmd->base.speed < ecmd.base.speed)
 279                         cmd->base.speed = ecmd.base.speed;
 280         }
 281
 282         return 0;
 283 }
 284
 285 static netdev_features_t br_fix_features(struct net_device *dev,
 286         netdev_features_t features)
 287 {
 288         struct net_bridge *br = netdev_priv(dev);
 289
 290         return br_features_recompute(br, features);
 291 }
 292
 293 #ifdef CONFIG_NET_POLL_CONTROLLER
 294 static void br_poll_controller(struct net_device *br_dev)
 295 {
 296 }
 297
 298 static void br_netpoll_cleanup(struct net_device *dev)
 299 {
 300         struct net_bridge *br = netdev_priv(dev);
 301         struct net_bridge_port *p;
 302
 303         list_for_each_entry(p, &br->port_list, list)
 304                 br_netpoll_disable(p);
 305 }
 306
 307 static int __br_netpoll_enable(struct net_bridge_port *p)
 308 {
 309         struct netpoll *np;
 310         int err;
 311
 312         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 313         if (!np)
 314                 return -ENOMEM;
 315
 316         err = __netpoll_setup(np, p->dev);
 317         if (err) {
 318                 kfree(np);
 319                 return err;
 320         }
 321
 322         p->np = np;
 323         return err;
 324 }
 325
 326 int br_netpoll_enable(struct net_bridge_port *p)
 327 {
 328         if (!p->br->dev->npinfo)
 329                 return 0;
 330
 331         return __br_netpoll_enable(p);
 332 }
 333
 334 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 335 {
 336         struct net_bridge *br = netdev_priv(dev);
 337         struct net_bridge_port *p;
 338         int err = 0;
 339
 340         list_for_each_entry(p, &br->port_list, list) {
 341                 if (!p->dev)
 342                         continue;
 343                 err = __br_netpoll_enable(p);
 344                 if (err)
 345                         goto fail;
 346         }
 347
 348 out:
 349         return err;
 350
 351 fail:
 352         br_netpoll_cleanup(dev);
 353         goto out;
 354 }
 355
 356 void br_netpoll_disable(struct net_bridge_port *p)
 357 {
 358         struct netpoll *np = p->np;
 359
 360         if (!np)
 361                 return;
 362
 363         p->np = NULL;
 364
 365         __netpoll_free(np);
 366 }
 367
 368 #endif
 369
 370 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 371                         struct netlink_ext_ack *extack)
 372
 373 {
 374         struct net_bridge *br = netdev_priv(dev);
 375
 376         return br_add_if(br, slave_dev, extack);
 377 }
 378
 379 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 380 {
 381         struct net_bridge *br = netdev_priv(dev);
 382
 383         return br_del_if(br, slave_dev);
 384 }
 385
 386 static int br_fill_forward_path(struct net_device_path_ctx *ctx,
 387                                 struct net_device_path *path)
 388 {
 389         struct net_bridge_fdb_entry *f;
 390         struct net_bridge_port *dst;
 391         struct net_bridge *br;
 392
 393         if (netif_is_bridge_port(ctx->dev))
 394                 return -1;
 395
 396         br = netdev_priv(ctx->dev);
 397
 398         br_vlan_fill_forward_path_pvid(br, ctx, path);
 399
 400         f = br_fdb_find_rcu(br, ctx->daddr, path->bridge.vlan_id);
 401         if (!f || !f->dst)
 402                 return -1;
 403
 404         dst = READ_ONCE(f->dst);
 405         if (!dst)
 406                 return -1;
 407
 408         if (br_vlan_fill_forward_path_mode(br, dst, path))
 409                 return -1;
 410
 411         path->type = DEV_PATH_BRIDGE;
 412         path->dev = dst->br->dev;
 413         ctx->dev = dst->dev;
 414
 415         switch (path->bridge.vlan_mode) {
 416         case DEV_PATH_BR_VLAN_TAG:
 417                 if (ctx->num_vlans >= ARRAY_SIZE(ctx->vlan))
 418                         return -ENOSPC;
 419                 ctx->vlan[ctx->num_vlans].id = path->bridge.vlan_id;
 420                 ctx->vlan[ctx->num_vlans].proto = path->bridge.vlan_proto;
 421                 ctx->num_vlans++;
 422                 break;
 423         case DEV_PATH_BR_VLAN_UNTAG_HW:
 424         case DEV_PATH_BR_VLAN_UNTAG:
 425                 ctx->num_vlans--;
 426                 break;
 427         case DEV_PATH_BR_VLAN_KEEP:
 428                 break;
 429         }
 430
 431         return 0;
 432 }
 433
 434 static const struct ethtool_ops br_ethtool_ops = {
 435         .get_drvinfo             = br_getinfo,
 436         .get_link                = ethtool_op_get_link,
 437         .get_link_ksettings      = br_get_link_ksettings,
 438 };
 439
 440 static const struct net_device_ops br_netdev_ops = {
 441         .ndo_open                = br_dev_open,
 442         .ndo_stop                = br_dev_stop,
 443         .ndo_init                = br_dev_init,
 444         .ndo_uninit              = br_dev_uninit,
 445         .ndo_start_xmit          = br_dev_xmit,
 446         .ndo_get_stats64         = dev_get_tstats64,
 447         .ndo_set_mac_address     = br_set_mac_address,
 448         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 449         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 450         .ndo_change_mtu          = br_change_mtu,
 451         .ndo_siocdevprivate      = br_dev_siocdevprivate,
 452 #ifdef CONFIG_NET_POLL_CONTROLLER
 453         .ndo_netpoll_setup       = br_netpoll_setup,
 454         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 455         .ndo_poll_controller     = br_poll_controller,
 456 #endif
 457         .ndo_add_slave           = br_add_slave,
 458         .ndo_del_slave           = br_del_slave,
 459         .ndo_fix_features        = br_fix_features,
 460         .ndo_fdb_add             = br_fdb_add,
 461         .ndo_fdb_del             = br_fdb_delete,
 462         .ndo_fdb_del_bulk        = br_fdb_delete_bulk,
 463         .ndo_fdb_dump            = br_fdb_dump,
 464         .ndo_fdb_get             = br_fdb_get,
 465         .ndo_mdb_add             = br_mdb_add,
 466         .ndo_mdb_del             = br_mdb_del,
 467         .ndo_mdb_del_bulk        = br_mdb_del_bulk,
 468         .ndo_mdb_dump            = br_mdb_dump,
 469         .ndo_mdb_get             = br_mdb_get,
 470         .ndo_bridge_getlink      = br_getlink,
 471         .ndo_bridge_setlink      = br_setlink,
 472         .ndo_bridge_dellink      = br_dellink,
 473         .ndo_features_check      = passthru_features_check,
 474         .ndo_fill_forward_path   = br_fill_forward_path,
 475 };
 476
 477 static struct device_type br_type = {
 478         .name   = "bridge",
 479 };
 480
 481 void br_dev_setup(struct net_device *dev)
 482 {
 483         struct net_bridge *br = netdev_priv(dev);
 484
 485         eth_hw_addr_random(dev);
 486         ether_setup(dev);
 487
 488         dev->netdev_ops = &br_netdev_ops;
 489         dev->needs_free_netdev = true;
 490         dev->ethtool_ops = &br_ethtool_ops;
 491         SET_NETDEV_DEVTYPE(dev, &br_type);
 492         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 493
 494         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 495                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 496         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 497                            NETIF_F_HW_VLAN_STAG_TX;
 498         dev->vlan_features = COMMON_FEATURES;
 499
 500         br->dev = dev;
 501         spin_lock_init(&br->lock);
 502         INIT_LIST_HEAD(&br->port_list);
 503         INIT_HLIST_HEAD(&br->fdb_list);
 504         INIT_HLIST_HEAD(&br->frame_type_list);
 505 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 506         INIT_HLIST_HEAD(&br->mrp_list);
 507 #endif
 508 #if IS_ENABLED(CONFIG_BRIDGE_CFM)
 509         INIT_HLIST_HEAD(&br->mep_list);
 510 #endif
 511         spin_lock_init(&br->hash_lock);
 512
 513         br->bridge_id.prio[0] = 0x80;
 514         br->bridge_id.prio[1] = 0x00;
 515
 516         ether_addr_copy(br->group_addr, eth_stp_addr);
 517
 518         br->stp_enabled = BR_NO_STP;
 519         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 520         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 521
 522         br->designated_root = br->bridge_id;
 523         br->bridge_max_age = br->max_age = 20 * HZ;
 524         br->bridge_hello_time = br->hello_time = 2 * HZ;
 525         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 526         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 527         dev->max_mtu = ETH_MAX_MTU;
 528
 529         br_netfilter_rtable_init(br);
 530         br_stp_timer_init(br);
 531         br_multicast_init(br);
 532         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 533 }