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 <net/netdev_lock.h>
  20
  21 #include "br_private.h"
  22
  23 #define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \
  24                          NETIF_F_GSO_MASK | NETIF_F_HW_CSUM)
  25
  26 const struct nf_br_ops __rcu *nf_br_ops __read_mostly;
  27 EXPORT_SYMBOL_GPL(nf_br_ops);
  28
  29 /* net device transmit always called with BH disabled */
  30 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
  31 {
  32         enum skb_drop_reason reason = pskb_may_pull_reason(skb, ETH_HLEN);
  33         struct net_bridge_mcast_port *pmctx_null = NULL;
  34         struct net_bridge *br = netdev_priv(dev);
  35         struct net_bridge_mcast *brmctx = &br->multicast_ctx;
  36         struct net_bridge_fdb_entry *dst;
  37         struct net_bridge_mdb_entry *mdst;
  38         const struct nf_br_ops *nf_ops;
  39         u8 state = BR_STATE_FORWARDING;
  40         struct net_bridge_vlan *vlan;
  41         const unsigned char *dest;
  42         u16 vid = 0;
  43
  44         if (unlikely(reason != SKB_NOT_DROPPED_YET)) {
  45                 kfree_skb_reason(skb, reason);
  46                 return NETDEV_TX_OK;
  47         }
  48
  49         memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
  50         br_tc_skb_miss_set(skb, false);
  51
  52         rcu_read_lock();
  53         nf_ops = rcu_dereference(nf_br_ops);
  54         if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
  55                 rcu_read_unlock();
  56                 return NETDEV_TX_OK;
  57         }
  58
  59         dev_sw_netstats_tx_add(dev, 1, skb->len);
  60
  61         br_switchdev_frame_unmark(skb);
  62         BR_INPUT_SKB_CB(skb)->brdev = dev;
  63         BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
  64
  65         skb_reset_mac_header(skb);
  66         skb_pull(skb, ETH_HLEN);
  67
  68         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid,
  69                                 &state, &vlan))
  70                 goto out;
  71
  72         if (IS_ENABLED(CONFIG_INET) &&
  73             (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) ||
  74              eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) &&
  75             br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
  76                 br_do_proxy_suppress_arp(skb, br, vid, NULL);
  77         } else if (IS_ENABLED(CONFIG_IPV6) &&
  78                    skb->protocol == htons(ETH_P_IPV6) &&
  79                    br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
  80                    pskb_may_pull(skb, sizeof(struct ipv6hdr) +
  81                                  sizeof(struct nd_msg)) &&
  82                    ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
  83                         struct nd_msg *msg, _msg;
  84
  85                         msg = br_is_nd_neigh_msg(skb, &_msg);
  86                         if (msg)
  87                                 br_do_suppress_nd(skb, br, vid, NULL, msg);
  88         }
  89
  90         dest = eth_hdr(skb)->h_dest;
  91         if (is_broadcast_ether_addr(dest)) {
  92                 br_flood(br, skb, BR_PKT_BROADCAST, false, true, vid);
  93         } else if (is_multicast_ether_addr(dest)) {
  94                 if (unlikely(netpoll_tx_running(dev))) {
  95                         br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid);
  96                         goto out;
  97                 }
  98                 if (br_multicast_rcv(&brmctx, &pmctx_null, vlan, skb, vid)) {
  99                         kfree_skb(skb);
 100                         goto out;
 101                 }
 102
 103                 mdst = br_mdb_entry_skb_get(brmctx, skb, vid);
 104                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
 105                     br_multicast_querier_exists(brmctx, eth_hdr(skb), mdst))
 106                         br_multicast_flood(mdst, skb, brmctx, false, true);
 107                 else
 108                         br_flood(br, skb, BR_PKT_MULTICAST, false, true, vid);
 109         } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
 110                 br_forward(dst->dst, skb, false, true);
 111         } else {
 112                 br_flood(br, skb, BR_PKT_UNICAST, false, true, vid);
 113         }
 114 out:
 115         rcu_read_unlock();
 116         return NETDEV_TX_OK;
 117 }
 118
 119 static int br_dev_init(struct net_device *dev)
 120 {
 121         struct net_bridge *br = netdev_priv(dev);
 122         int err;
 123
 124         err = br_fdb_hash_init(br);
 125         if (err)
 126                 return err;
 127
 128         err = br_mdb_hash_init(br);
 129         if (err) {
 130                 br_fdb_hash_fini(br);
 131                 return err;
 132         }
 133
 134         err = br_vlan_init(br);
 135         if (err) {
 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                 br_vlan_flush(br);
 144                 br_mdb_hash_fini(br);
 145                 br_fdb_hash_fini(br);
 146                 return err;
 147         }
 148
 149         netdev_lockdep_set_classes(dev);
 150         return 0;
 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 }
 163
 164 static int br_dev_open(struct net_device *dev)
 165 {
 166         struct net_bridge *br = netdev_priv(dev);
 167
 168         netdev_update_features(dev);
 169         netif_start_queue(dev);
 170         br_stp_enable_bridge(br);
 171         br_multicast_open(br);
 172
 173         if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 174                 br_multicast_join_snoopers(br);
 175
 176         return 0;
 177 }
 178
 179 static void br_dev_set_multicast_list(struct net_device *dev)
 180 {
 181 }
 182
 183 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 184 {
 185         if (change & IFF_PROMISC)
 186                 br_manage_promisc(netdev_priv(dev));
 187 }
 188
 189 static int br_dev_stop(struct net_device *dev)
 190 {
 191         struct net_bridge *br = netdev_priv(dev);
 192
 193         br_stp_disable_bridge(br);
 194         br_multicast_stop(br);
 195
 196         if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 197                 br_multicast_leave_snoopers(br);
 198
 199         netif_stop_queue(dev);
 200
 201         return 0;
 202 }
 203
 204 static int br_change_mtu(struct net_device *dev, int new_mtu)
 205 {
 206         struct net_bridge *br = netdev_priv(dev);
 207
 208         WRITE_ONCE(dev->mtu, new_mtu);
 209
 210         /* this flag will be cleared if the MTU was automatically adjusted */
 211         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 212 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 213         /* remember the MTU in the rtable for PMTU */
 214         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 215 #endif
 216
 217         return 0;
 218 }
 219
 220 /* Allow setting mac address to any valid ethernet address. */
 221 static int br_set_mac_address(struct net_device *dev, void *p)
 222 {
 223         struct net_bridge *br = netdev_priv(dev);
 224         struct sockaddr *addr = p;
 225
 226         if (!is_valid_ether_addr(addr->sa_data))
 227                 return -EADDRNOTAVAIL;
 228
 229         /* dev_set_mac_addr() can be called by a master device on bridge's
 230          * NETDEV_UNREGISTER, but since it's being destroyed do nothing
 231          */
 232         if (dev->reg_state != NETREG_REGISTERED)
 233                 return -EBUSY;
 234
 235         spin_lock_bh(&br->lock);
 236         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 237                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 238                 br_stp_change_bridge_id(br, addr->sa_data);
 239         }
 240         spin_unlock_bh(&br->lock);
 241
 242         return 0;
 243 }
 244
 245 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 246 {
 247         strscpy(info->driver, "bridge", sizeof(info->driver));
 248         strscpy(info->version, BR_VERSION, sizeof(info->version));
 249         strscpy(info->fw_version, "N/A", sizeof(info->fw_version));
 250         strscpy(info->bus_info, "N/A", sizeof(info->bus_info));
 251 }
 252
 253 static int br_get_link_ksettings(struct net_device *dev,
 254                                  struct ethtool_link_ksettings *cmd)
 255 {
 256         struct net_bridge *br = netdev_priv(dev);
 257         struct net_bridge_port *p;
 258
 259         cmd->base.duplex = DUPLEX_UNKNOWN;
 260         cmd->base.port = PORT_OTHER;
 261         cmd->base.speed = SPEED_UNKNOWN;
 262
 263         list_for_each_entry(p, &br->port_list, list) {
 264                 struct ethtool_link_ksettings ecmd;
 265                 struct net_device *pdev = p->dev;
 266
 267                 if (!netif_running(pdev) || !netif_oper_up(pdev))
 268                         continue;
 269
 270                 if (__ethtool_get_link_ksettings(pdev, &ecmd))
 271                         continue;
 272
 273                 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
 274                         continue;
 275
 276                 if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
 277                     cmd->base.speed < ecmd.base.speed)
 278                         cmd->base.speed = ecmd.base.speed;
 279         }
 280
 281         return 0;
 282 }
 283
 284 static netdev_features_t br_fix_features(struct net_device *dev,
 285         netdev_features_t features)
 286 {
 287         struct net_bridge *br = netdev_priv(dev);
 288
 289         return br_features_recompute(br, features);
 290 }
 291
 292 #ifdef CONFIG_NET_POLL_CONTROLLER
 293 static void br_poll_controller(struct net_device *br_dev)
 294 {
 295 }
 296
 297 static void br_netpoll_cleanup(struct net_device *dev)
 298 {
 299         struct net_bridge *br = netdev_priv(dev);
 300         struct net_bridge_port *p;
 301
 302         list_for_each_entry(p, &br->port_list, list)
 303                 br_netpoll_disable(p);
 304 }
 305
 306 static int __br_netpoll_enable(struct net_bridge_port *p)
 307 {
 308         struct netpoll *np;
 309         int err;
 310
 311         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 312         if (!np)
 313                 return -ENOMEM;
 314
 315         err = __netpoll_setup(np, p->dev);
 316         if (err) {
 317                 kfree(np);
 318                 return err;
 319         }
 320
 321         p->np = np;
 322         return err;
 323 }
 324
 325 int br_netpoll_enable(struct net_bridge_port *p)
 326 {
 327         if (!p->br->dev->npinfo)
 328                 return 0;
 329
 330         return __br_netpoll_enable(p);
 331 }
 332
 333 static int br_netpoll_setup(struct net_device *dev)
 334 {
 335         struct net_bridge *br = netdev_priv(dev);
 336         struct net_bridge_port *p;
 337         int err = 0;
 338
 339         list_for_each_entry(p, &br->port_list, list) {
 340                 if (!p->dev)
 341                         continue;
 342                 err = __br_netpoll_enable(p);
 343                 if (err)
 344                         goto fail;
 345         }
 346
 347 out:
 348         return err;
 349
 350 fail:
 351         br_netpoll_cleanup(dev);
 352         goto out;
 353 }
 354
 355 void br_netpoll_disable(struct net_bridge_port *p)
 356 {
 357         struct netpoll *np = p->np;
 358
 359         if (!np)
 360                 return;
 361
 362         p->np = NULL;
 363
 364         __netpoll_free(np);
 365 }
 366
 367 #endif
 368
 369 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 370                         struct netlink_ext_ack *extack)
 371
 372 {
 373         struct net_bridge *br = netdev_priv(dev);
 374
 375         return br_add_if(br, slave_dev, extack);
 376 }
 377
 378 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 379 {
 380         struct net_bridge *br = netdev_priv(dev);
 381
 382         return br_del_if(br, slave_dev);
 383 }
 384
 385 static int br_fill_forward_path(struct net_device_path_ctx *ctx,
 386                                 struct net_device_path *path)
 387 {
 388         struct net_bridge_fdb_entry *f;
 389         struct net_bridge_port *dst;
 390         struct net_bridge *br;
 391
 392         if (netif_is_bridge_port(ctx->dev))
 393                 return -1;
 394
 395         br = netdev_priv(ctx->dev);
 396
 397         br_vlan_fill_forward_path_pvid(br, ctx, path);
 398
 399         f = br_fdb_find_rcu(br, ctx->daddr, path->bridge.vlan_id);
 400         if (!f)
 401                 return -1;
 402
 403         dst = READ_ONCE(f->dst);
 404         if (!dst)
 405                 return -1;
 406
 407         if (br_vlan_fill_forward_path_mode(br, dst, path))
 408                 return -1;
 409
 410         path->type = DEV_PATH_BRIDGE;
 411         path->dev = dst->br->dev;
 412         ctx->dev = dst->dev;
 413
 414         switch (path->bridge.vlan_mode) {
 415         case DEV_PATH_BR_VLAN_TAG:
 416                 if (ctx->num_vlans >= ARRAY_SIZE(ctx->vlan))
 417                         return -ENOSPC;
 418                 ctx->vlan[ctx->num_vlans].id = path->bridge.vlan_id;
 419                 ctx->vlan[ctx->num_vlans].proto = path->bridge.vlan_proto;
 420                 ctx->num_vlans++;
 421                 break;
 422         case DEV_PATH_BR_VLAN_UNTAG_HW:
 423         case DEV_PATH_BR_VLAN_UNTAG:
 424                 ctx->num_vlans--;
 425                 break;
 426         case DEV_PATH_BR_VLAN_KEEP:
 427                 break;
 428         }
 429
 430         return 0;
 431 }
 432
 433 static const struct ethtool_ops br_ethtool_ops = {
 434         .get_drvinfo             = br_getinfo,
 435         .get_link                = ethtool_op_get_link,
 436         .get_link_ksettings      = br_get_link_ksettings,
 437 };
 438
 439 static const struct net_device_ops br_netdev_ops = {
 440         .ndo_open                = br_dev_open,
 441         .ndo_stop                = br_dev_stop,
 442         .ndo_init                = br_dev_init,
 443         .ndo_uninit              = br_dev_uninit,
 444         .ndo_start_xmit          = br_dev_xmit,
 445         .ndo_get_stats64         = dev_get_tstats64,
 446         .ndo_set_mac_address     = br_set_mac_address,
 447         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 448         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 449         .ndo_change_mtu          = br_change_mtu,
 450         .ndo_siocdevprivate      = br_dev_siocdevprivate,
 451 #ifdef CONFIG_NET_POLL_CONTROLLER
 452         .ndo_netpoll_setup       = br_netpoll_setup,
 453         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 454         .ndo_poll_controller     = br_poll_controller,
 455 #endif
 456         .ndo_add_slave           = br_add_slave,
 457         .ndo_del_slave           = br_del_slave,
 458         .ndo_fix_features        = br_fix_features,
 459         .ndo_fdb_add             = br_fdb_add,
 460         .ndo_fdb_del             = br_fdb_delete,
 461         .ndo_fdb_del_bulk        = br_fdb_delete_bulk,
 462         .ndo_fdb_dump            = br_fdb_dump,
 463         .ndo_fdb_get             = br_fdb_get,
 464         .ndo_mdb_add             = br_mdb_add,
 465         .ndo_mdb_del             = br_mdb_del,
 466         .ndo_mdb_del_bulk        = br_mdb_del_bulk,
 467         .ndo_mdb_dump            = br_mdb_dump,
 468         .ndo_mdb_get             = br_mdb_get,
 469         .ndo_bridge_getlink      = br_getlink,
 470         .ndo_bridge_setlink      = br_setlink,
 471         .ndo_bridge_dellink      = br_dellink,
 472         .ndo_features_check      = passthru_features_check,
 473         .ndo_fill_forward_path   = br_fill_forward_path,
 474 };
 475
 476 static const struct device_type br_type = {
 477         .name   = "bridge",
 478 };
 479
 480 void br_dev_setup(struct net_device *dev)
 481 {
 482         struct net_bridge *br = netdev_priv(dev);
 483
 484         eth_hw_addr_random(dev);
 485         ether_setup(dev);
 486
 487         dev->netdev_ops = &br_netdev_ops;
 488         dev->needs_free_netdev = true;
 489         dev->ethtool_ops = &br_ethtool_ops;
 490         SET_NETDEV_DEVTYPE(dev, &br_type);
 491         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 492         dev->lltx = true;
 493         dev->netns_immutable = true;
 494
 495         dev->features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 496                         NETIF_F_HW_VLAN_STAG_TX;
 497         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 498                            NETIF_F_HW_VLAN_STAG_TX;
 499         dev->vlan_features = COMMON_FEATURES;
 500         dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 501
 502         br->dev = dev;
 503         spin_lock_init(&br->lock);
 504         INIT_LIST_HEAD(&br->port_list);
 505         INIT_HLIST_HEAD(&br->fdb_list);
 506         INIT_HLIST_HEAD(&br->frame_type_list);
 507 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 508         INIT_HLIST_HEAD(&br->mrp_list);
 509 #endif
 510 #if IS_ENABLED(CONFIG_BRIDGE_CFM)
 511         INIT_HLIST_HEAD(&br->mep_list);
 512 #endif
 513         spin_lock_init(&br->hash_lock);
 514
 515         br->bridge_id.prio[0] = 0x80;
 516         br->bridge_id.prio[1] = 0x00;
 517
 518         ether_addr_copy(br->group_addr, eth_stp_addr);
 519
 520         br->stp_enabled = BR_NO_STP;
 521         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 522         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 523
 524         br->designated_root = br->bridge_id;
 525         br->bridge_max_age = br->max_age = 20 * HZ;
 526         br->bridge_hello_time = br->hello_time = 2 * HZ;
 527         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 528         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 529         dev->max_mtu = ETH_MAX_MTU;
 530
 531         br_netfilter_rtable_init(br);
 532         br_stp_timer_init(br);
 533         br_multicast_init(br);
 534         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 535 }