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
  43         rcu_read_lock();
  44         nf_ops = rcu_dereference(nf_br_ops);
  45         if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
  46                 rcu_read_unlock();
  47                 return NETDEV_TX_OK;
  48         }
  49
  50         dev_sw_netstats_tx_add(dev, 1, skb->len);
  51
  52         br_switchdev_frame_unmark(skb);
  53         BR_INPUT_SKB_CB(skb)->brdev = dev;
  54         BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
  55
  56         skb_reset_mac_header(skb);
  57         skb_pull(skb, ETH_HLEN);
  58
  59         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid,
  60                                 &state, &vlan))
  61                 goto out;
  62
  63         if (IS_ENABLED(CONFIG_INET) &&
  64             (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) ||
  65              eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) &&
  66             br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
  67                 br_do_proxy_suppress_arp(skb, br, vid, NULL);
  68         } else if (IS_ENABLED(CONFIG_IPV6) &&
  69                    skb->protocol == htons(ETH_P_IPV6) &&
  70                    br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
  71                    pskb_may_pull(skb, sizeof(struct ipv6hdr) +
  72                                  sizeof(struct nd_msg)) &&
  73                    ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
  74                         struct nd_msg *msg, _msg;
  75
  76                         msg = br_is_nd_neigh_msg(skb, &_msg);
  77                         if (msg)
  78                                 br_do_suppress_nd(skb, br, vid, NULL, msg);
  79         }
  80
  81         dest = eth_hdr(skb)->h_dest;
  82         if (is_broadcast_ether_addr(dest)) {
  83                 br_flood(br, skb, BR_PKT_BROADCAST, false, true);
  84         } else if (is_multicast_ether_addr(dest)) {
  85                 if (unlikely(netpoll_tx_running(dev))) {
  86                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  87                         goto out;
  88                 }
  89                 if (br_multicast_rcv(&brmctx, &pmctx_null, vlan, skb, vid)) {
  90                         kfree_skb(skb);
  91                         goto out;
  92                 }
  93
  94                 mdst = br_mdb_get(brmctx, skb, vid);
  95                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
  96                     br_multicast_querier_exists(brmctx, eth_hdr(skb), mdst))
  97                         br_multicast_flood(mdst, skb, brmctx, false, true);
  98                 else
  99                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
 100         } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
 101                 br_forward(dst->dst, skb, false, true);
 102         } else {
 103                 br_flood(br, skb, BR_PKT_UNICAST, false, true);
 104         }
 105 out:
 106         rcu_read_unlock();
 107         return NETDEV_TX_OK;
 108 }
 109
 110 static struct lock_class_key bridge_netdev_addr_lock_key;
 111
 112 static void br_set_lockdep_class(struct net_device *dev)
 113 {
 114         lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key);
 115 }
 116
 117 static int br_dev_init(struct net_device *dev)
 118 {
 119         struct net_bridge *br = netdev_priv(dev);
 120         int err;
 121
 122         dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 123         if (!dev->tstats)
 124                 return -ENOMEM;
 125
 126         err = br_fdb_hash_init(br);
 127         if (err) {
 128                 free_percpu(dev->tstats);
 129                 return err;
 130         }
 131
 132         err = br_mdb_hash_init(br);
 133         if (err) {
 134                 free_percpu(dev->tstats);
 135                 br_fdb_hash_fini(br);
 136                 return err;
 137         }
 138
 139         err = br_vlan_init(br);
 140         if (err) {
 141                 free_percpu(dev->tstats);
 142                 br_mdb_hash_fini(br);
 143                 br_fdb_hash_fini(br);
 144                 return err;
 145         }
 146
 147         err = br_multicast_init_stats(br);
 148         if (err) {
 149                 free_percpu(dev->tstats);
 150                 br_vlan_flush(br);
 151                 br_mdb_hash_fini(br);
 152                 br_fdb_hash_fini(br);
 153         }
 154
 155         br_set_lockdep_class(dev);
 156         return err;
 157 }
 158
 159 static void br_dev_uninit(struct net_device *dev)
 160 {
 161         struct net_bridge *br = netdev_priv(dev);
 162
 163         br_multicast_dev_del(br);
 164         br_multicast_uninit_stats(br);
 165         br_vlan_flush(br);
 166         br_mdb_hash_fini(br);
 167         br_fdb_hash_fini(br);
 168         free_percpu(dev->tstats);
 169 }
 170
 171 static int br_dev_open(struct net_device *dev)
 172 {
 173         struct net_bridge *br = netdev_priv(dev);
 174
 175         netdev_update_features(dev);
 176         netif_start_queue(dev);
 177         br_stp_enable_bridge(br);
 178         br_multicast_open(br);
 179
 180         if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 181                 br_multicast_join_snoopers(br);
 182
 183         return 0;
 184 }
 185
 186 static void br_dev_set_multicast_list(struct net_device *dev)
 187 {
 188 }
 189
 190 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 191 {
 192         if (change & IFF_PROMISC)
 193                 br_manage_promisc(netdev_priv(dev));
 194 }
 195
 196 static int br_dev_stop(struct net_device *dev)
 197 {
 198         struct net_bridge *br = netdev_priv(dev);
 199
 200         br_stp_disable_bridge(br);
 201         br_multicast_stop(br);
 202
 203         if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 204                 br_multicast_leave_snoopers(br);
 205
 206         netif_stop_queue(dev);
 207
 208         return 0;
 209 }
 210
 211 static int br_change_mtu(struct net_device *dev, int new_mtu)
 212 {
 213         struct net_bridge *br = netdev_priv(dev);
 214
 215         dev->mtu = new_mtu;
 216
 217         /* this flag will be cleared if the MTU was automatically adjusted */
 218         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 219 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 220         /* remember the MTU in the rtable for PMTU */
 221         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 222 #endif
 223
 224         return 0;
 225 }
 226
 227 /* Allow setting mac address to any valid ethernet address. */
 228 static int br_set_mac_address(struct net_device *dev, void *p)
 229 {
 230         struct net_bridge *br = netdev_priv(dev);
 231         struct sockaddr *addr = p;
 232
 233         if (!is_valid_ether_addr(addr->sa_data))
 234                 return -EADDRNOTAVAIL;
 235
 236         /* dev_set_mac_addr() can be called by a master device on bridge's
 237          * NETDEV_UNREGISTER, but since it's being destroyed do nothing
 238          */
 239         if (dev->reg_state != NETREG_REGISTERED)
 240                 return -EBUSY;
 241
 242         spin_lock_bh(&br->lock);
 243         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 244                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 245                 br_stp_change_bridge_id(br, addr->sa_data);
 246         }
 247         spin_unlock_bh(&br->lock);
 248
 249         return 0;
 250 }
 251
 252 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 253 {
 254         strlcpy(info->driver, "bridge", sizeof(info->driver));
 255         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 256         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 257         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 258 }
 259
 260 static int br_get_link_ksettings(struct net_device *dev,
 261                                  struct ethtool_link_ksettings *cmd)
 262 {
 263         struct net_bridge *br = netdev_priv(dev);
 264         struct net_bridge_port *p;
 265
 266         cmd->base.duplex = DUPLEX_UNKNOWN;
 267         cmd->base.port = PORT_OTHER;
 268         cmd->base.speed = SPEED_UNKNOWN;
 269
 270         list_for_each_entry(p, &br->port_list, list) {
 271                 struct ethtool_link_ksettings ecmd;
 272                 struct net_device *pdev = p->dev;
 273
 274                 if (!netif_running(pdev) || !netif_oper_up(pdev))
 275                         continue;
 276
 277                 if (__ethtool_get_link_ksettings(pdev, &ecmd))
 278                         continue;
 279
 280                 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
 281                         continue;
 282
 283                 if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
 284                     cmd->base.speed < ecmd.base.speed)
 285                         cmd->base.speed = ecmd.base.speed;
 286         }
 287
 288         return 0;
 289 }
 290
 291 static netdev_features_t br_fix_features(struct net_device *dev,
 292         netdev_features_t features)
 293 {
 294         struct net_bridge *br = netdev_priv(dev);
 295
 296         return br_features_recompute(br, features);
 297 }
 298
 299 #ifdef CONFIG_NET_POLL_CONTROLLER
 300 static void br_poll_controller(struct net_device *br_dev)
 301 {
 302 }
 303
 304 static void br_netpoll_cleanup(struct net_device *dev)
 305 {
 306         struct net_bridge *br = netdev_priv(dev);
 307         struct net_bridge_port *p;
 308
 309         list_for_each_entry(p, &br->port_list, list)
 310                 br_netpoll_disable(p);
 311 }
 312
 313 static int __br_netpoll_enable(struct net_bridge_port *p)
 314 {
 315         struct netpoll *np;
 316         int err;
 317
 318         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 319         if (!np)
 320                 return -ENOMEM;
 321
 322         err = __netpoll_setup(np, p->dev);
 323         if (err) {
 324                 kfree(np);
 325                 return err;
 326         }
 327
 328         p->np = np;
 329         return err;
 330 }
 331
 332 int br_netpoll_enable(struct net_bridge_port *p)
 333 {
 334         if (!p->br->dev->npinfo)
 335                 return 0;
 336
 337         return __br_netpoll_enable(p);
 338 }
 339
 340 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 341 {
 342         struct net_bridge *br = netdev_priv(dev);
 343         struct net_bridge_port *p;
 344         int err = 0;
 345
 346         list_for_each_entry(p, &br->port_list, list) {
 347                 if (!p->dev)
 348                         continue;
 349                 err = __br_netpoll_enable(p);
 350                 if (err)
 351                         goto fail;
 352         }
 353
 354 out:
 355         return err;
 356
 357 fail:
 358         br_netpoll_cleanup(dev);
 359         goto out;
 360 }
 361
 362 void br_netpoll_disable(struct net_bridge_port *p)
 363 {
 364         struct netpoll *np = p->np;
 365
 366         if (!np)
 367                 return;
 368
 369         p->np = NULL;
 370
 371         __netpoll_free(np);
 372 }
 373
 374 #endif
 375
 376 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 377                         struct netlink_ext_ack *extack)
 378
 379 {
 380         struct net_bridge *br = netdev_priv(dev);
 381
 382         return br_add_if(br, slave_dev, extack);
 383 }
 384
 385 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 386 {
 387         struct net_bridge *br = netdev_priv(dev);
 388
 389         return br_del_if(br, slave_dev);
 390 }
 391
 392 static int br_fill_forward_path(struct net_device_path_ctx *ctx,
 393                                 struct net_device_path *path)
 394 {
 395         struct net_bridge_fdb_entry *f;
 396         struct net_bridge_port *dst;
 397         struct net_bridge *br;
 398
 399         if (netif_is_bridge_port(ctx->dev))
 400                 return -1;
 401
 402         br = netdev_priv(ctx->dev);
 403
 404         br_vlan_fill_forward_path_pvid(br, ctx, path);
 405
 406         f = br_fdb_find_rcu(br, ctx->daddr, path->bridge.vlan_id);
 407         if (!f || !f->dst)
 408                 return -1;
 409
 410         dst = READ_ONCE(f->dst);
 411         if (!dst)
 412                 return -1;
 413
 414         if (br_vlan_fill_forward_path_mode(br, dst, path))
 415                 return -1;
 416
 417         path->type = DEV_PATH_BRIDGE;
 418         path->dev = dst->br->dev;
 419         ctx->dev = dst->dev;
 420
 421         switch (path->bridge.vlan_mode) {
 422         case DEV_PATH_BR_VLAN_TAG:
 423                 if (ctx->num_vlans >= ARRAY_SIZE(ctx->vlan))
 424                         return -ENOSPC;
 425                 ctx->vlan[ctx->num_vlans].id = path->bridge.vlan_id;
 426                 ctx->vlan[ctx->num_vlans].proto = path->bridge.vlan_proto;
 427                 ctx->num_vlans++;
 428                 break;
 429         case DEV_PATH_BR_VLAN_UNTAG_HW:
 430         case DEV_PATH_BR_VLAN_UNTAG:
 431                 ctx->num_vlans--;
 432                 break;
 433         case DEV_PATH_BR_VLAN_KEEP:
 434                 break;
 435         }
 436
 437         return 0;
 438 }
 439
 440 static const struct ethtool_ops br_ethtool_ops = {
 441         .get_drvinfo             = br_getinfo,
 442         .get_link                = ethtool_op_get_link,
 443         .get_link_ksettings      = br_get_link_ksettings,
 444 };
 445
 446 static const struct net_device_ops br_netdev_ops = {
 447         .ndo_open                = br_dev_open,
 448         .ndo_stop                = br_dev_stop,
 449         .ndo_init                = br_dev_init,
 450         .ndo_uninit              = br_dev_uninit,
 451         .ndo_start_xmit          = br_dev_xmit,
 452         .ndo_get_stats64         = dev_get_tstats64,
 453         .ndo_set_mac_address     = br_set_mac_address,
 454         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 455         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 456         .ndo_change_mtu          = br_change_mtu,
 457         .ndo_siocdevprivate      = br_dev_siocdevprivate,
 458 #ifdef CONFIG_NET_POLL_CONTROLLER
 459         .ndo_netpoll_setup       = br_netpoll_setup,
 460         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 461         .ndo_poll_controller     = br_poll_controller,
 462 #endif
 463         .ndo_add_slave           = br_add_slave,
 464         .ndo_del_slave           = br_del_slave,
 465         .ndo_fix_features        = br_fix_features,
 466         .ndo_fdb_add             = br_fdb_add,
 467         .ndo_fdb_del             = br_fdb_delete,
 468         .ndo_fdb_dump            = br_fdb_dump,
 469         .ndo_fdb_get             = br_fdb_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 }