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 *br = netdev_priv(dev);
  31         struct net_bridge_fdb_entry *dst;
  32         struct net_bridge_mdb_entry *mdst;
  33         struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);
  34         const struct nf_br_ops *nf_ops;
  35         u8 state = BR_STATE_FORWARDING;
  36         const unsigned char *dest;
  37         struct ethhdr *eth;
  38         u16 vid = 0;
  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         u64_stats_update_begin(&brstats->syncp);
  48         brstats->tx_packets++;
  49         brstats->tx_bytes += skb->len;
  50         u64_stats_update_end(&brstats->syncp);
  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         eth = eth_hdr(skb);
  58         skb_pull(skb, ETH_HLEN);
  59
  60         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid, &state))
  61                 goto out;
  62
  63         if (IS_ENABLED(CONFIG_INET) &&
  64             (eth->h_proto == htons(ETH_P_ARP) ||
  65              eth->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(br, NULL, skb, vid)) {
  90                         kfree_skb(skb);
  91                         goto out;
  92                 }
  93
  94                 mdst = br_mdb_get(br, skb, vid);
  95                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
  96                     br_multicast_querier_exists(br, eth_hdr(skb)))
  97                         br_multicast_flood(mdst, skb, 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 int br_dev_init(struct net_device *dev)
 111 {
 112         struct net_bridge *br = netdev_priv(dev);
 113         int err;
 114
 115         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 116         if (!br->stats)
 117                 return -ENOMEM;
 118
 119         err = br_fdb_hash_init(br);
 120         if (err) {
 121                 free_percpu(br->stats);
 122                 return err;
 123         }
 124
 125         err = br_mdb_hash_init(br);
 126         if (err) {
 127                 free_percpu(br->stats);
 128                 br_fdb_hash_fini(br);
 129                 return err;
 130         }
 131
 132         err = br_vlan_init(br);
 133         if (err) {
 134                 free_percpu(br->stats);
 135                 br_mdb_hash_fini(br);
 136                 br_fdb_hash_fini(br);
 137                 return err;
 138         }
 139
 140         err = br_multicast_init_stats(br);
 141         if (err) {
 142                 free_percpu(br->stats);
 143                 br_vlan_flush(br);
 144                 br_mdb_hash_fini(br);
 145                 br_fdb_hash_fini(br);
 146         }
 147
 148         return err;
 149 }
 150
 151 static void br_dev_uninit(struct net_device *dev)
 152 {
 153         struct net_bridge *br = netdev_priv(dev);
 154
 155         br_multicast_dev_del(br);
 156         br_multicast_uninit_stats(br);
 157         br_vlan_flush(br);
 158         br_mdb_hash_fini(br);
 159         br_fdb_hash_fini(br);
 160         free_percpu(br->stats);
 161 }
 162
 163 static int br_dev_open(struct net_device *dev)
 164 {
 165         struct net_bridge *br = netdev_priv(dev);
 166
 167         netdev_update_features(dev);
 168         netif_start_queue(dev);
 169         br_stp_enable_bridge(br);
 170         br_multicast_open(br);
 171
 172         return 0;
 173 }
 174
 175 static void br_dev_set_multicast_list(struct net_device *dev)
 176 {
 177 }
 178
 179 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 180 {
 181         if (change & IFF_PROMISC)
 182                 br_manage_promisc(netdev_priv(dev));
 183 }
 184
 185 static int br_dev_stop(struct net_device *dev)
 186 {
 187         struct net_bridge *br = netdev_priv(dev);
 188
 189         br_stp_disable_bridge(br);
 190         br_multicast_stop(br);
 191
 192         netif_stop_queue(dev);
 193
 194         return 0;
 195 }
 196
 197 static void br_get_stats64(struct net_device *dev,
 198                            struct rtnl_link_stats64 *stats)
 199 {
 200         struct net_bridge *br = netdev_priv(dev);
 201         struct pcpu_sw_netstats tmp, sum = { 0 };
 202         unsigned int cpu;
 203
 204         for_each_possible_cpu(cpu) {
 205                 unsigned int start;
 206                 const struct pcpu_sw_netstats *bstats
 207                         = per_cpu_ptr(br->stats, cpu);
 208                 do {
 209                         start = u64_stats_fetch_begin_irq(&bstats->syncp);
 210                         memcpy(&tmp, bstats, sizeof(tmp));
 211                 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
 212                 sum.tx_bytes   += tmp.tx_bytes;
 213                 sum.tx_packets += tmp.tx_packets;
 214                 sum.rx_bytes   += tmp.rx_bytes;
 215                 sum.rx_packets += tmp.rx_packets;
 216         }
 217
 218         stats->tx_bytes   = sum.tx_bytes;
 219         stats->tx_packets = sum.tx_packets;
 220         stats->rx_bytes   = sum.rx_bytes;
 221         stats->rx_packets = sum.rx_packets;
 222 }
 223
 224 static int br_change_mtu(struct net_device *dev, int new_mtu)
 225 {
 226         struct net_bridge *br = netdev_priv(dev);
 227
 228         dev->mtu = new_mtu;
 229
 230         /* this flag will be cleared if the MTU was automatically adjusted */
 231         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 232 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 233         /* remember the MTU in the rtable for PMTU */
 234         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 235 #endif
 236
 237         return 0;
 238 }
 239
 240 /* Allow setting mac address to any valid ethernet address. */
 241 static int br_set_mac_address(struct net_device *dev, void *p)
 242 {
 243         struct net_bridge *br = netdev_priv(dev);
 244         struct sockaddr *addr = p;
 245
 246         if (!is_valid_ether_addr(addr->sa_data))
 247                 return -EADDRNOTAVAIL;
 248
 249         /* dev_set_mac_addr() can be called by a master device on bridge's
 250          * NETDEV_UNREGISTER, but since it's being destroyed do nothing
 251          */
 252         if (dev->reg_state != NETREG_REGISTERED)
 253                 return -EBUSY;
 254
 255         spin_lock_bh(&br->lock);
 256         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 257                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 258                 br_stp_change_bridge_id(br, addr->sa_data);
 259         }
 260         spin_unlock_bh(&br->lock);
 261
 262         return 0;
 263 }
 264
 265 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 266 {
 267         strlcpy(info->driver, "bridge", sizeof(info->driver));
 268         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 269         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 270         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 271 }
 272
 273 static int br_get_link_ksettings(struct net_device *dev,
 274                                  struct ethtool_link_ksettings *cmd)
 275 {
 276         struct net_bridge *br = netdev_priv(dev);
 277         struct net_bridge_port *p;
 278
 279         cmd->base.duplex = DUPLEX_UNKNOWN;
 280         cmd->base.port = PORT_OTHER;
 281         cmd->base.speed = SPEED_UNKNOWN;
 282
 283         list_for_each_entry(p, &br->port_list, list) {
 284                 struct ethtool_link_ksettings ecmd;
 285                 struct net_device *pdev = p->dev;
 286
 287                 if (!netif_running(pdev) || !netif_oper_up(pdev))
 288                         continue;
 289
 290                 if (__ethtool_get_link_ksettings(pdev, &ecmd))
 291                         continue;
 292
 293                 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
 294                         continue;
 295
 296                 if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
 297                     cmd->base.speed < ecmd.base.speed)
 298                         cmd->base.speed = ecmd.base.speed;
 299         }
 300
 301         return 0;
 302 }
 303
 304 static netdev_features_t br_fix_features(struct net_device *dev,
 305         netdev_features_t features)
 306 {
 307         struct net_bridge *br = netdev_priv(dev);
 308
 309         return br_features_recompute(br, features);
 310 }
 311
 312 #ifdef CONFIG_NET_POLL_CONTROLLER
 313 static void br_poll_controller(struct net_device *br_dev)
 314 {
 315 }
 316
 317 static void br_netpoll_cleanup(struct net_device *dev)
 318 {
 319         struct net_bridge *br = netdev_priv(dev);
 320         struct net_bridge_port *p;
 321
 322         list_for_each_entry(p, &br->port_list, list)
 323                 br_netpoll_disable(p);
 324 }
 325
 326 static int __br_netpoll_enable(struct net_bridge_port *p)
 327 {
 328         struct netpoll *np;
 329         int err;
 330
 331         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 332         if (!np)
 333                 return -ENOMEM;
 334
 335         err = __netpoll_setup(np, p->dev);
 336         if (err) {
 337                 kfree(np);
 338                 return err;
 339         }
 340
 341         p->np = np;
 342         return err;
 343 }
 344
 345 int br_netpoll_enable(struct net_bridge_port *p)
 346 {
 347         if (!p->br->dev->npinfo)
 348                 return 0;
 349
 350         return __br_netpoll_enable(p);
 351 }
 352
 353 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 354 {
 355         struct net_bridge *br = netdev_priv(dev);
 356         struct net_bridge_port *p;
 357         int err = 0;
 358
 359         list_for_each_entry(p, &br->port_list, list) {
 360                 if (!p->dev)
 361                         continue;
 362                 err = __br_netpoll_enable(p);
 363                 if (err)
 364                         goto fail;
 365         }
 366
 367 out:
 368         return err;
 369
 370 fail:
 371         br_netpoll_cleanup(dev);
 372         goto out;
 373 }
 374
 375 void br_netpoll_disable(struct net_bridge_port *p)
 376 {
 377         struct netpoll *np = p->np;
 378
 379         if (!np)
 380                 return;
 381
 382         p->np = NULL;
 383
 384         __netpoll_free(np);
 385 }
 386
 387 #endif
 388
 389 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 390                         struct netlink_ext_ack *extack)
 391
 392 {
 393         struct net_bridge *br = netdev_priv(dev);
 394
 395         return br_add_if(br, slave_dev, extack);
 396 }
 397
 398 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 399 {
 400         struct net_bridge *br = netdev_priv(dev);
 401
 402         return br_del_if(br, slave_dev);
 403 }
 404
 405 static const struct ethtool_ops br_ethtool_ops = {
 406         .get_drvinfo             = br_getinfo,
 407         .get_link                = ethtool_op_get_link,
 408         .get_link_ksettings      = br_get_link_ksettings,
 409 };
 410
 411 static const struct net_device_ops br_netdev_ops = {
 412         .ndo_open                = br_dev_open,
 413         .ndo_stop                = br_dev_stop,
 414         .ndo_init                = br_dev_init,
 415         .ndo_uninit              = br_dev_uninit,
 416         .ndo_start_xmit          = br_dev_xmit,
 417         .ndo_get_stats64         = br_get_stats64,
 418         .ndo_set_mac_address     = br_set_mac_address,
 419         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 420         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 421         .ndo_change_mtu          = br_change_mtu,
 422         .ndo_do_ioctl            = br_dev_ioctl,
 423 #ifdef CONFIG_NET_POLL_CONTROLLER
 424         .ndo_netpoll_setup       = br_netpoll_setup,
 425         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 426         .ndo_poll_controller     = br_poll_controller,
 427 #endif
 428         .ndo_add_slave           = br_add_slave,
 429         .ndo_del_slave           = br_del_slave,
 430         .ndo_fix_features        = br_fix_features,
 431         .ndo_fdb_add             = br_fdb_add,
 432         .ndo_fdb_del             = br_fdb_delete,
 433         .ndo_fdb_dump            = br_fdb_dump,
 434         .ndo_fdb_get             = br_fdb_get,
 435         .ndo_bridge_getlink      = br_getlink,
 436         .ndo_bridge_setlink      = br_setlink,
 437         .ndo_bridge_dellink      = br_dellink,
 438         .ndo_features_check      = passthru_features_check,
 439 };
 440
 441 static struct device_type br_type = {
 442         .name   = "bridge",
 443 };
 444
 445 void br_dev_setup(struct net_device *dev)
 446 {
 447         struct net_bridge *br = netdev_priv(dev);
 448
 449         eth_hw_addr_random(dev);
 450         ether_setup(dev);
 451
 452         dev->netdev_ops = &br_netdev_ops;
 453         dev->needs_free_netdev = true;
 454         dev->ethtool_ops = &br_ethtool_ops;
 455         SET_NETDEV_DEVTYPE(dev, &br_type);
 456         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 457
 458         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 459                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 460         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 461                            NETIF_F_HW_VLAN_STAG_TX;
 462         dev->vlan_features = COMMON_FEATURES;
 463
 464         br->dev = dev;
 465         spin_lock_init(&br->lock);
 466         INIT_LIST_HEAD(&br->port_list);
 467         INIT_HLIST_HEAD(&br->fdb_list);
 468         spin_lock_init(&br->hash_lock);
 469
 470         br->bridge_id.prio[0] = 0x80;
 471         br->bridge_id.prio[1] = 0x00;
 472
 473         ether_addr_copy(br->group_addr, eth_stp_addr);
 474
 475         br->stp_enabled = BR_NO_STP;
 476         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 477         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 478
 479         br->designated_root = br->bridge_id;
 480         br->bridge_max_age = br->max_age = 20 * HZ;
 481         br->bridge_hello_time = br->hello_time = 2 * HZ;
 482         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 483         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 484         dev->max_mtu = ETH_MAX_MTU;
 485
 486         br_netfilter_rtable_init(br);
 487         br_stp_timer_init(br);
 488         br_multicast_init(br);
 489         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 490 }