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 struct lock_class_key bridge_netdev_addr_lock_key;
 112
 113 static void br_set_lockdep_class(struct net_device *dev)
 114 {
 115         lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key);
 116 }
 117
 118 static int br_dev_init(struct net_device *dev)
 119 {
 120         struct net_bridge *br = netdev_priv(dev);
 121         int err;
 122
 123         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 124         if (!dev->tstats)
 125                 return -ENOMEM;
 126
 127         err = br_fdb_hash_init(br);
 128         if (err) {
 129                 free_percpu(dev->tstats);
 130                 return err;
 131         }
 132
 133         err = br_mdb_hash_init(br);
 134         if (err) {
 135                 free_percpu(dev->tstats);
 136                 br_fdb_hash_fini(br);
 137                 return err;
 138         }
 139
 140         err = br_vlan_init(br);
 141         if (err) {
 142                 free_percpu(dev->tstats);
 143                 br_mdb_hash_fini(br);
 144                 br_fdb_hash_fini(br);
 145                 return err;
 146         }
 147
 148         err = br_multicast_init_stats(br);
 149         if (err) {
 150                 free_percpu(dev->tstats);
 151                 br_vlan_flush(br);
 152                 br_mdb_hash_fini(br);
 153                 br_fdb_hash_fini(br);
 154         }
 155
 156         br_set_lockdep_class(dev);
 157         return err;
 158 }
 159
 160 static void br_dev_uninit(struct net_device *dev)
 161 {
 162         struct net_bridge *br = netdev_priv(dev);
 163
 164         br_multicast_dev_del(br);
 165         br_multicast_uninit_stats(br);
 166         br_vlan_flush(br);
 167         br_mdb_hash_fini(br);
 168         br_fdb_hash_fini(br);
 169         free_percpu(dev->tstats);
 170 }
 171
 172 static int br_dev_open(struct net_device *dev)
 173 {
 174         struct net_bridge *br = netdev_priv(dev);
 175
 176         netdev_update_features(dev);
 177         netif_start_queue(dev);
 178         br_stp_enable_bridge(br);
 179         br_multicast_open(br);
 180
 181         if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 182                 br_multicast_join_snoopers(br);
 183
 184         return 0;
 185 }
 186
 187 static void br_dev_set_multicast_list(struct net_device *dev)
 188 {
 189 }
 190
 191 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 192 {
 193         if (change & IFF_PROMISC)
 194                 br_manage_promisc(netdev_priv(dev));
 195 }
 196
 197 static int br_dev_stop(struct net_device *dev)
 198 {
 199         struct net_bridge *br = netdev_priv(dev);
 200
 201         br_stp_disable_bridge(br);
 202         br_multicast_stop(br);
 203
 204         if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 205                 br_multicast_leave_snoopers(br);
 206
 207         netif_stop_queue(dev);
 208
 209         return 0;
 210 }
 211
 212 static int br_change_mtu(struct net_device *dev, int new_mtu)
 213 {
 214         struct net_bridge *br = netdev_priv(dev);
 215
 216         dev->mtu = new_mtu;
 217
 218         /* this flag will be cleared if the MTU was automatically adjusted */
 219         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 220 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 221         /* remember the MTU in the rtable for PMTU */
 222         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 223 #endif
 224
 225         return 0;
 226 }
 227
 228 /* Allow setting mac address to any valid ethernet address. */
 229 static int br_set_mac_address(struct net_device *dev, void *p)
 230 {
 231         struct net_bridge *br = netdev_priv(dev);
 232         struct sockaddr *addr = p;
 233
 234         if (!is_valid_ether_addr(addr->sa_data))
 235                 return -EADDRNOTAVAIL;
 236
 237         /* dev_set_mac_addr() can be called by a master device on bridge's
 238          * NETDEV_UNREGISTER, but since it's being destroyed do nothing
 239          */
 240         if (dev->reg_state != NETREG_REGISTERED)
 241                 return -EBUSY;
 242
 243         spin_lock_bh(&br->lock);
 244         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 245                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 246                 br_stp_change_bridge_id(br, addr->sa_data);
 247         }
 248         spin_unlock_bh(&br->lock);
 249
 250         return 0;
 251 }
 252
 253 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 254 {
 255         strscpy(info->driver, "bridge", sizeof(info->driver));
 256         strscpy(info->version, BR_VERSION, sizeof(info->version));
 257         strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
 258         strscpy(info->bus_info, "N/A", sizeof(info->bus_info));
 259 }
 260
 261 static int br_get_link_ksettings(struct net_device *dev,
 262                                  struct ethtool_link_ksettings *cmd)
 263 {
 264         struct net_bridge *br = netdev_priv(dev);
 265         struct net_bridge_port *p;
 266
 267         cmd->base.duplex = DUPLEX_UNKNOWN;
 268         cmd->base.port = PORT_OTHER;
 269         cmd->base.speed = SPEED_UNKNOWN;
 270
 271         list_for_each_entry(p, &br->port_list, list) {
 272                 struct ethtool_link_ksettings ecmd;
 273                 struct net_device *pdev = p->dev;
 274
 275                 if (!netif_running(pdev) || !netif_oper_up(pdev))
 276                         continue;
 277
 278                 if (__ethtool_get_link_ksettings(pdev, &ecmd))
 279                         continue;
 280
 281                 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
 282                         continue;
 283
 284                 if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
 285                     cmd->base.speed < ecmd.base.speed)
 286                         cmd->base.speed = ecmd.base.speed;
 287         }
 288
 289         return 0;
 290 }
 291
 292 static netdev_features_t br_fix_features(struct net_device *dev,
 293         netdev_features_t features)
 294 {
 295         struct net_bridge *br = netdev_priv(dev);
 296
 297         return br_features_recompute(br, features);
 298 }
 299
 300 #ifdef CONFIG_NET_POLL_CONTROLLER
 301 static void br_poll_controller(struct net_device *br_dev)
 302 {
 303 }
 304
 305 static void br_netpoll_cleanup(struct net_device *dev)
 306 {
 307         struct net_bridge *br = netdev_priv(dev);
 308         struct net_bridge_port *p;
 309
 310         list_for_each_entry(p, &br->port_list, list)
 311                 br_netpoll_disable(p);
 312 }
 313
 314 static int __br_netpoll_enable(struct net_bridge_port *p)
 315 {
 316         struct netpoll *np;
 317         int err;
 318
 319         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 320         if (!np)
 321                 return -ENOMEM;
 322
 323         err = __netpoll_setup(np, p->dev);
 324         if (err) {
 325                 kfree(np);
 326                 return err;
 327         }
 328
 329         p->np = np;
 330         return err;
 331 }
 332
 333 int br_netpoll_enable(struct net_bridge_port *p)
 334 {
 335         if (!p->br->dev->npinfo)
 336                 return 0;
 337
 338         return __br_netpoll_enable(p);
 339 }
 340
 341 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 342 {
 343         struct net_bridge *br = netdev_priv(dev);
 344         struct net_bridge_port *p;
 345         int err = 0;
 346
 347         list_for_each_entry(p, &br->port_list, list) {
 348                 if (!p->dev)
 349                         continue;
 350                 err = __br_netpoll_enable(p);
 351                 if (err)
 352                         goto fail;
 353         }
 354
 355 out:
 356         return err;
 357
 358 fail:
 359         br_netpoll_cleanup(dev);
 360         goto out;
 361 }
 362
 363 void br_netpoll_disable(struct net_bridge_port *p)
 364 {
 365         struct netpoll *np = p->np;
 366
 367         if (!np)
 368                 return;
 369
 370         p->np = NULL;
 371
 372         __netpoll_free(np);
 373 }
 374
 375 #endif
 376
 377 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 378                         struct netlink_ext_ack *extack)
 379
 380 {
 381         struct net_bridge *br = netdev_priv(dev);
 382
 383         return br_add_if(br, slave_dev, extack);
 384 }
 385
 386 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 387 {
 388         struct net_bridge *br = netdev_priv(dev);
 389
 390         return br_del_if(br, slave_dev);
 391 }
 392
 393 static int br_fill_forward_path(struct net_device_path_ctx *ctx,
 394                                 struct net_device_path *path)
 395 {
 396         struct net_bridge_fdb_entry *f;
 397         struct net_bridge_port *dst;
 398         struct net_bridge *br;
 399
 400         if (netif_is_bridge_port(ctx->dev))
 401                 return -1;
 402
 403         br = netdev_priv(ctx->dev);
 404
 405         br_vlan_fill_forward_path_pvid(br, ctx, path);
 406
 407         f = br_fdb_find_rcu(br, ctx->daddr, path->bridge.vlan_id);
 408         if (!f || !f->dst)
 409                 return -1;
 410
 411         dst = READ_ONCE(f->dst);
 412         if (!dst)
 413                 return -1;
 414
 415         if (br_vlan_fill_forward_path_mode(br, dst, path))
 416                 return -1;
 417
 418         path->type = DEV_PATH_BRIDGE;
 419         path->dev = dst->br->dev;
 420         ctx->dev = dst->dev;
 421
 422         switch (path->bridge.vlan_mode) {
 423         case DEV_PATH_BR_VLAN_TAG:
 424                 if (ctx->num_vlans >= ARRAY_SIZE(ctx->vlan))
 425                         return -ENOSPC;
 426                 ctx->vlan[ctx->num_vlans].id = path->bridge.vlan_id;
 427                 ctx->vlan[ctx->num_vlans].proto = path->bridge.vlan_proto;
 428                 ctx->num_vlans++;
 429                 break;
 430         case DEV_PATH_BR_VLAN_UNTAG_HW:
 431         case DEV_PATH_BR_VLAN_UNTAG:
 432                 ctx->num_vlans--;
 433                 break;
 434         case DEV_PATH_BR_VLAN_KEEP:
 435                 break;
 436         }
 437
 438         return 0;
 439 }
 440
 441 static const struct ethtool_ops br_ethtool_ops = {
 442         .get_drvinfo             = br_getinfo,
 443         .get_link                = ethtool_op_get_link,
 444         .get_link_ksettings      = br_get_link_ksettings,
 445 };
 446
 447 static const struct net_device_ops br_netdev_ops = {
 448         .ndo_open                = br_dev_open,
 449         .ndo_stop                = br_dev_stop,
 450         .ndo_init                = br_dev_init,
 451         .ndo_uninit              = br_dev_uninit,
 452         .ndo_start_xmit          = br_dev_xmit,
 453         .ndo_get_stats64         = dev_get_tstats64,
 454         .ndo_set_mac_address     = br_set_mac_address,
 455         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 456         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 457         .ndo_change_mtu          = br_change_mtu,
 458         .ndo_siocdevprivate      = br_dev_siocdevprivate,
 459 #ifdef CONFIG_NET_POLL_CONTROLLER
 460         .ndo_netpoll_setup       = br_netpoll_setup,
 461         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 462         .ndo_poll_controller     = br_poll_controller,
 463 #endif
 464         .ndo_add_slave           = br_add_slave,
 465         .ndo_del_slave           = br_del_slave,
 466         .ndo_fix_features        = br_fix_features,
 467         .ndo_fdb_add             = br_fdb_add,
 468         .ndo_fdb_del             = br_fdb_delete,
 469         .ndo_fdb_del_bulk        = br_fdb_delete_bulk,
 470         .ndo_fdb_dump            = br_fdb_dump,
 471         .ndo_fdb_get             = br_fdb_get,
 472         .ndo_mdb_add             = br_mdb_add,
 473         .ndo_mdb_del             = br_mdb_del,
 474         .ndo_mdb_del_bulk        = br_mdb_del_bulk,
 475         .ndo_mdb_dump            = br_mdb_dump,
 476         .ndo_mdb_get             = br_mdb_get,
 477         .ndo_bridge_getlink      = br_getlink,
 478         .ndo_bridge_setlink      = br_setlink,
 479         .ndo_bridge_dellink      = br_dellink,
 480         .ndo_features_check      = passthru_features_check,
 481         .ndo_fill_forward_path   = br_fill_forward_path,
 482 };
 483
 484 static struct device_type br_type = {
 485         .name   = "bridge",
 486 };
 487
 488 void br_dev_setup(struct net_device *dev)
 489 {
 490         struct net_bridge *br = netdev_priv(dev);
 491
 492         eth_hw_addr_random(dev);
 493         ether_setup(dev);
 494
 495         dev->netdev_ops = &br_netdev_ops;
 496         dev->needs_free_netdev = true;
 497         dev->ethtool_ops = &br_ethtool_ops;
 498         SET_NETDEV_DEVTYPE(dev, &br_type);
 499         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 500
 501         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 502                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 503         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 504                            NETIF_F_HW_VLAN_STAG_TX;
 505         dev->vlan_features = COMMON_FEATURES;
 506
 507         br->dev = dev;
 508         spin_lock_init(&br->lock);
 509         INIT_LIST_HEAD(&br->port_list);
 510         INIT_HLIST_HEAD(&br->fdb_list);
 511         INIT_HLIST_HEAD(&br->frame_type_list);
 512 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 513         INIT_HLIST_HEAD(&br->mrp_list);
 514 #endif
 515 #if IS_ENABLED(CONFIG_BRIDGE_CFM)
 516         INIT_HLIST_HEAD(&br->mep_list);
 517 #endif
 518         spin_lock_init(&br->hash_lock);
 519
 520         br->bridge_id.prio[0] = 0x80;
 521         br->bridge_id.prio[1] = 0x00;
 522
 523         ether_addr_copy(br->group_addr, eth_stp_addr);
 524
 525         br->stp_enabled = BR_NO_STP;
 526         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 527         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 528
 529         br->designated_root = br->bridge_id;
 530         br->bridge_max_age = br->max_age = 20 * HZ;
 531         br->bridge_hello_time = br->hello_time = 2 * HZ;
 532         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 533         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 534         dev->max_mtu = ETH_MAX_MTU;
 535
 536         br_netfilter_rtable_init(br);
 537         br_stp_timer_init(br);
 538         br_multicast_init(br);
 539         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 540 }