linux/net/bridge/br_device.c
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   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
  24const struct nf_br_ops __rcu *nf_br_ops __read_mostly;
  25EXPORT_SYMBOL_GPL(nf_br_ops);
  26
  27/* net device transmit always called with BH disabled */
  28netdev_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        const struct nf_br_ops *nf_ops;
  34        u8 state = BR_STATE_FORWARDING;
  35        const unsigned char *dest;
  36        u16 vid = 0;
  37
  38        memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
  39
  40        rcu_read_lock();
  41        nf_ops = rcu_dereference(nf_br_ops);
  42        if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
  43                rcu_read_unlock();
  44                return NETDEV_TX_OK;
  45        }
  46
  47        dev_sw_netstats_tx_add(dev, 1, skb->len);
  48
  49        br_switchdev_frame_unmark(skb);
  50        BR_INPUT_SKB_CB(skb)->brdev = dev;
  51        BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
  52
  53        skb_reset_mac_header(skb);
  54        skb_pull(skb, ETH_HLEN);
  55
  56        if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid, &state))
  57                goto out;
  58
  59        if (IS_ENABLED(CONFIG_INET) &&
  60            (eth_hdr(skb)->h_proto == htons(ETH_P_ARP) ||
  61             eth_hdr(skb)->h_proto == htons(ETH_P_RARP)) &&
  62            br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
  63                br_do_proxy_suppress_arp(skb, br, vid, NULL);
  64        } else if (IS_ENABLED(CONFIG_IPV6) &&
  65                   skb->protocol == htons(ETH_P_IPV6) &&
  66                   br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
  67                   pskb_may_pull(skb, sizeof(struct ipv6hdr) +
  68                                 sizeof(struct nd_msg)) &&
  69                   ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
  70                        struct nd_msg *msg, _msg;
  71
  72                        msg = br_is_nd_neigh_msg(skb, &_msg);
  73                        if (msg)
  74                                br_do_suppress_nd(skb, br, vid, NULL, msg);
  75        }
  76
  77        dest = eth_hdr(skb)->h_dest;
  78        if (is_broadcast_ether_addr(dest)) {
  79                br_flood(br, skb, BR_PKT_BROADCAST, false, true);
  80        } else if (is_multicast_ether_addr(dest)) {
  81                if (unlikely(netpoll_tx_running(dev))) {
  82                        br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  83                        goto out;
  84                }
  85                if (br_multicast_rcv(br, NULL, skb, vid)) {
  86                        kfree_skb(skb);
  87                        goto out;
  88                }
  89
  90                mdst = br_mdb_get(br, skb, vid);
  91                if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
  92                    br_multicast_querier_exists(br, eth_hdr(skb), mdst))
  93                        br_multicast_flood(mdst, skb, false, true);
  94                else
  95                        br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  96        } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
  97                br_forward(dst->dst, skb, false, true);
  98        } else {
  99                br_flood(br, skb, BR_PKT_UNICAST, false, true);
 100        }
 101out:
 102        rcu_read_unlock();
 103        return NETDEV_TX_OK;
 104}
 105
 106static struct lock_class_key bridge_netdev_addr_lock_key;
 107
 108static void br_set_lockdep_class(struct net_device *dev)
 109{
 110        lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key);
 111}
 112
 113static int br_dev_init(struct net_device *dev)
 114{
 115        struct net_bridge *br = netdev_priv(dev);
 116        int err;
 117
 118        dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 119        if (!dev->tstats)
 120                return -ENOMEM;
 121
 122        err = br_fdb_hash_init(br);
 123        if (err) {
 124                free_percpu(dev->tstats);
 125                return err;
 126        }
 127
 128        err = br_mdb_hash_init(br);
 129        if (err) {
 130                free_percpu(dev->tstats);
 131                br_fdb_hash_fini(br);
 132                return err;
 133        }
 134
 135        err = br_vlan_init(br);
 136        if (err) {
 137                free_percpu(dev->tstats);
 138                br_mdb_hash_fini(br);
 139                br_fdb_hash_fini(br);
 140                return err;
 141        }
 142
 143        err = br_multicast_init_stats(br);
 144        if (err) {
 145                free_percpu(dev->tstats);
 146                br_vlan_flush(br);
 147                br_mdb_hash_fini(br);
 148                br_fdb_hash_fini(br);
 149        }
 150
 151        br_set_lockdep_class(dev);
 152        return err;
 153}
 154
 155static void br_dev_uninit(struct net_device *dev)
 156{
 157        struct net_bridge *br = netdev_priv(dev);
 158
 159        br_multicast_dev_del(br);
 160        br_multicast_uninit_stats(br);
 161        br_vlan_flush(br);
 162        br_mdb_hash_fini(br);
 163        br_fdb_hash_fini(br);
 164        free_percpu(dev->tstats);
 165}
 166
 167static int br_dev_open(struct net_device *dev)
 168{
 169        struct net_bridge *br = netdev_priv(dev);
 170
 171        netdev_update_features(dev);
 172        netif_start_queue(dev);
 173        br_stp_enable_bridge(br);
 174        br_multicast_open(br);
 175
 176        if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 177                br_multicast_join_snoopers(br);
 178
 179        return 0;
 180}
 181
 182static void br_dev_set_multicast_list(struct net_device *dev)
 183{
 184}
 185
 186static void br_dev_change_rx_flags(struct net_device *dev, int change)
 187{
 188        if (change & IFF_PROMISC)
 189                br_manage_promisc(netdev_priv(dev));
 190}
 191
 192static int br_dev_stop(struct net_device *dev)
 193{
 194        struct net_bridge *br = netdev_priv(dev);
 195
 196        br_stp_disable_bridge(br);
 197        br_multicast_stop(br);
 198
 199        if (br_opt_get(br, BROPT_MULTICAST_ENABLED))
 200                br_multicast_leave_snoopers(br);
 201
 202        netif_stop_queue(dev);
 203
 204        return 0;
 205}
 206
 207static int br_change_mtu(struct net_device *dev, int new_mtu)
 208{
 209        struct net_bridge *br = netdev_priv(dev);
 210
 211        dev->mtu = new_mtu;
 212
 213        /* this flag will be cleared if the MTU was automatically adjusted */
 214        br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 215#if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 216        /* remember the MTU in the rtable for PMTU */
 217        dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 218#endif
 219
 220        return 0;
 221}
 222
 223/* Allow setting mac address to any valid ethernet address. */
 224static int br_set_mac_address(struct net_device *dev, void *p)
 225{
 226        struct net_bridge *br = netdev_priv(dev);
 227        struct sockaddr *addr = p;
 228
 229        if (!is_valid_ether_addr(addr->sa_data))
 230                return -EADDRNOTAVAIL;
 231
 232        /* dev_set_mac_addr() can be called by a master device on bridge's
 233         * NETDEV_UNREGISTER, but since it's being destroyed do nothing
 234         */
 235        if (dev->reg_state != NETREG_REGISTERED)
 236                return -EBUSY;
 237
 238        spin_lock_bh(&br->lock);
 239        if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 240                /* Mac address will be changed in br_stp_change_bridge_id(). */
 241                br_stp_change_bridge_id(br, addr->sa_data);
 242        }
 243        spin_unlock_bh(&br->lock);
 244
 245        return 0;
 246}
 247
 248static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 249{
 250        strlcpy(info->driver, "bridge", sizeof(info->driver));
 251        strlcpy(info->version, BR_VERSION, sizeof(info->version));
 252        strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 253        strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 254}
 255
 256static int br_get_link_ksettings(struct net_device *dev,
 257                                 struct ethtool_link_ksettings *cmd)
 258{
 259        struct net_bridge *br = netdev_priv(dev);
 260        struct net_bridge_port *p;
 261
 262        cmd->base.duplex = DUPLEX_UNKNOWN;
 263        cmd->base.port = PORT_OTHER;
 264        cmd->base.speed = SPEED_UNKNOWN;
 265
 266        list_for_each_entry(p, &br->port_list, list) {
 267                struct ethtool_link_ksettings ecmd;
 268                struct net_device *pdev = p->dev;
 269
 270                if (!netif_running(pdev) || !netif_oper_up(pdev))
 271                        continue;
 272
 273                if (__ethtool_get_link_ksettings(pdev, &ecmd))
 274                        continue;
 275
 276                if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
 277                        continue;
 278
 279                if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
 280                    cmd->base.speed < ecmd.base.speed)
 281                        cmd->base.speed = ecmd.base.speed;
 282        }
 283
 284        return 0;
 285}
 286
 287static netdev_features_t br_fix_features(struct net_device *dev,
 288        netdev_features_t features)
 289{
 290        struct net_bridge *br = netdev_priv(dev);
 291
 292        return br_features_recompute(br, features);
 293}
 294
 295#ifdef CONFIG_NET_POLL_CONTROLLER
 296static void br_poll_controller(struct net_device *br_dev)
 297{
 298}
 299
 300static void br_netpoll_cleanup(struct net_device *dev)
 301{
 302        struct net_bridge *br = netdev_priv(dev);
 303        struct net_bridge_port *p;
 304
 305        list_for_each_entry(p, &br->port_list, list)
 306                br_netpoll_disable(p);
 307}
 308
 309static int __br_netpoll_enable(struct net_bridge_port *p)
 310{
 311        struct netpoll *np;
 312        int err;
 313
 314        np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 315        if (!np)
 316                return -ENOMEM;
 317
 318        err = __netpoll_setup(np, p->dev);
 319        if (err) {
 320                kfree(np);
 321                return err;
 322        }
 323
 324        p->np = np;
 325        return err;
 326}
 327
 328int br_netpoll_enable(struct net_bridge_port *p)
 329{
 330        if (!p->br->dev->npinfo)
 331                return 0;
 332
 333        return __br_netpoll_enable(p);
 334}
 335
 336static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 337{
 338        struct net_bridge *br = netdev_priv(dev);
 339        struct net_bridge_port *p;
 340        int err = 0;
 341
 342        list_for_each_entry(p, &br->port_list, list) {
 343                if (!p->dev)
 344                        continue;
 345                err = __br_netpoll_enable(p);
 346                if (err)
 347                        goto fail;
 348        }
 349
 350out:
 351        return err;
 352
 353fail:
 354        br_netpoll_cleanup(dev);
 355        goto out;
 356}
 357
 358void br_netpoll_disable(struct net_bridge_port *p)
 359{
 360        struct netpoll *np = p->np;
 361
 362        if (!np)
 363                return;
 364
 365        p->np = NULL;
 366
 367        __netpoll_free(np);
 368}
 369
 370#endif
 371
 372static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 373                        struct netlink_ext_ack *extack)
 374
 375{
 376        struct net_bridge *br = netdev_priv(dev);
 377
 378        return br_add_if(br, slave_dev, extack);
 379}
 380
 381static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 382{
 383        struct net_bridge *br = netdev_priv(dev);
 384
 385        return br_del_if(br, slave_dev);
 386}
 387
 388static int br_fill_forward_path(struct net_device_path_ctx *ctx,
 389                                struct net_device_path *path)
 390{
 391        struct net_bridge_fdb_entry *f;
 392        struct net_bridge_port *dst;
 393        struct net_bridge *br;
 394
 395        if (netif_is_bridge_port(ctx->dev))
 396                return -1;
 397
 398        br = netdev_priv(ctx->dev);
 399
 400        br_vlan_fill_forward_path_pvid(br, ctx, path);
 401
 402        f = br_fdb_find_rcu(br, ctx->daddr, path->bridge.vlan_id);
 403        if (!f || !f->dst)
 404                return -1;
 405
 406        dst = READ_ONCE(f->dst);
 407        if (!dst)
 408                return -1;
 409
 410        if (br_vlan_fill_forward_path_mode(br, dst, path))
 411                return -1;
 412
 413        path->type = DEV_PATH_BRIDGE;
 414        path->dev = dst->br->dev;
 415        ctx->dev = dst->dev;
 416
 417        switch (path->bridge.vlan_mode) {
 418        case DEV_PATH_BR_VLAN_TAG:
 419                if (ctx->num_vlans >= ARRAY_SIZE(ctx->vlan))
 420                        return -ENOSPC;
 421                ctx->vlan[ctx->num_vlans].id = path->bridge.vlan_id;
 422                ctx->vlan[ctx->num_vlans].proto = path->bridge.vlan_proto;
 423                ctx->num_vlans++;
 424                break;
 425        case DEV_PATH_BR_VLAN_UNTAG_HW:
 426        case DEV_PATH_BR_VLAN_UNTAG:
 427                ctx->num_vlans--;
 428                break;
 429        case DEV_PATH_BR_VLAN_KEEP:
 430                break;
 431        }
 432
 433        return 0;
 434}
 435
 436static const struct ethtool_ops br_ethtool_ops = {
 437        .get_drvinfo             = br_getinfo,
 438        .get_link                = ethtool_op_get_link,
 439        .get_link_ksettings      = br_get_link_ksettings,
 440};
 441
 442static const struct net_device_ops br_netdev_ops = {
 443        .ndo_open                = br_dev_open,
 444        .ndo_stop                = br_dev_stop,
 445        .ndo_init                = br_dev_init,
 446        .ndo_uninit              = br_dev_uninit,
 447        .ndo_start_xmit          = br_dev_xmit,
 448        .ndo_get_stats64         = dev_get_tstats64,
 449        .ndo_set_mac_address     = br_set_mac_address,
 450        .ndo_set_rx_mode         = br_dev_set_multicast_list,
 451        .ndo_change_rx_flags     = br_dev_change_rx_flags,
 452        .ndo_change_mtu          = br_change_mtu,
 453        .ndo_do_ioctl            = br_dev_ioctl,
 454#ifdef CONFIG_NET_POLL_CONTROLLER
 455        .ndo_netpoll_setup       = br_netpoll_setup,
 456        .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 457        .ndo_poll_controller     = br_poll_controller,
 458#endif
 459        .ndo_add_slave           = br_add_slave,
 460        .ndo_del_slave           = br_del_slave,
 461        .ndo_fix_features        = br_fix_features,
 462        .ndo_fdb_add             = br_fdb_add,
 463        .ndo_fdb_del             = br_fdb_delete,
 464        .ndo_fdb_dump            = br_fdb_dump,
 465        .ndo_fdb_get             = br_fdb_get,
 466        .ndo_bridge_getlink      = br_getlink,
 467        .ndo_bridge_setlink      = br_setlink,
 468        .ndo_bridge_dellink      = br_dellink,
 469        .ndo_features_check      = passthru_features_check,
 470        .ndo_fill_forward_path   = br_fill_forward_path,
 471};
 472
 473static struct device_type br_type = {
 474        .name   = "bridge",
 475};
 476
 477void br_dev_setup(struct net_device *dev)
 478{
 479        struct net_bridge *br = netdev_priv(dev);
 480
 481        eth_hw_addr_random(dev);
 482        ether_setup(dev);
 483
 484        dev->netdev_ops = &br_netdev_ops;
 485        dev->needs_free_netdev = true;
 486        dev->ethtool_ops = &br_ethtool_ops;
 487        SET_NETDEV_DEVTYPE(dev, &br_type);
 488        dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 489
 490        dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 491                        NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 492        dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 493                           NETIF_F_HW_VLAN_STAG_TX;
 494        dev->vlan_features = COMMON_FEATURES;
 495
 496        br->dev = dev;
 497        spin_lock_init(&br->lock);
 498        INIT_LIST_HEAD(&br->port_list);
 499        INIT_HLIST_HEAD(&br->fdb_list);
 500        INIT_HLIST_HEAD(&br->frame_type_list);
 501#if IS_ENABLED(CONFIG_BRIDGE_MRP)
 502        INIT_HLIST_HEAD(&br->mrp_list);
 503#endif
 504#if IS_ENABLED(CONFIG_BRIDGE_CFM)
 505        INIT_HLIST_HEAD(&br->mep_list);
 506#endif
 507        spin_lock_init(&br->hash_lock);
 508
 509        br->bridge_id.prio[0] = 0x80;
 510        br->bridge_id.prio[1] = 0x00;
 511
 512        ether_addr_copy(br->group_addr, eth_stp_addr);
 513
 514        br->stp_enabled = BR_NO_STP;
 515        br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 516        br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 517
 518        br->designated_root = br->bridge_id;
 519        br->bridge_max_age = br->max_age = 20 * HZ;
 520        br->bridge_hello_time = br->hello_time = 2 * HZ;
 521        br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 522        br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 523        dev->max_mtu = ETH_MAX_MTU;
 524
 525        br_netfilter_rtable_init(br);
 526        br_stp_timer_init(br);
 527        br_multicast_init(br);
 528        INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 529}
 530