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         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         }
 101 out:
 102         rcu_read_unlock();
 103         return NETDEV_TX_OK;
 104 }
 105
 106 static struct lock_class_key bridge_netdev_addr_lock_key;
 107
 108 static 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
 113 static 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
 155 static 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
 167 static 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
 182 static void br_dev_set_multicast_list(struct net_device *dev)
 183 {
 184 }
 185
 186 static 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
 192 static 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
 207 static 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. */
 224 static 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
 248 static 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
 256 static 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
 287 static 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
 296 static void br_poll_controller(struct net_device *br_dev)
 297 {
 298 }
 299
 300 static 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
 309 static 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
 328 int 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
 336 static 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
 350 out:
 351         return err;
 352
 353 fail:
 354         br_netpoll_cleanup(dev);
 355         goto out;
 356 }
 357
 358 void 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
 372 static 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
 381 static 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
 388 static const struct ethtool_ops br_ethtool_ops = {
 389         .get_drvinfo             = br_getinfo,
 390         .get_link                = ethtool_op_get_link,
 391         .get_link_ksettings      = br_get_link_ksettings,
 392 };
 393
 394 static const struct net_device_ops br_netdev_ops = {
 395         .ndo_open                = br_dev_open,
 396         .ndo_stop                = br_dev_stop,
 397         .ndo_init                = br_dev_init,
 398         .ndo_uninit              = br_dev_uninit,
 399         .ndo_start_xmit          = br_dev_xmit,
 400         .ndo_get_stats64         = dev_get_tstats64,
 401         .ndo_set_mac_address     = br_set_mac_address,
 402         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 403         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 404         .ndo_change_mtu          = br_change_mtu,
 405         .ndo_do_ioctl            = br_dev_ioctl,
 406 #ifdef CONFIG_NET_POLL_CONTROLLER
 407         .ndo_netpoll_setup       = br_netpoll_setup,
 408         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 409         .ndo_poll_controller     = br_poll_controller,
 410 #endif
 411         .ndo_add_slave           = br_add_slave,
 412         .ndo_del_slave           = br_del_slave,
 413         .ndo_fix_features        = br_fix_features,
 414         .ndo_fdb_add             = br_fdb_add,
 415         .ndo_fdb_del             = br_fdb_delete,
 416         .ndo_fdb_dump            = br_fdb_dump,
 417         .ndo_fdb_get             = br_fdb_get,
 418         .ndo_bridge_getlink      = br_getlink,
 419         .ndo_bridge_setlink      = br_setlink,
 420         .ndo_bridge_dellink      = br_dellink,
 421         .ndo_features_check      = passthru_features_check,
 422 };
 423
 424 static struct device_type br_type = {
 425         .name   = "bridge",
 426 };
 427
 428 void br_dev_setup(struct net_device *dev)
 429 {
 430         struct net_bridge *br = netdev_priv(dev);
 431
 432         eth_hw_addr_random(dev);
 433         ether_setup(dev);
 434
 435         dev->netdev_ops = &br_netdev_ops;
 436         dev->needs_free_netdev = true;
 437         dev->ethtool_ops = &br_ethtool_ops;
 438         SET_NETDEV_DEVTYPE(dev, &br_type);
 439         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 440
 441         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 442                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 443         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 444                            NETIF_F_HW_VLAN_STAG_TX;
 445         dev->vlan_features = COMMON_FEATURES;
 446
 447         br->dev = dev;
 448         spin_lock_init(&br->lock);
 449         INIT_LIST_HEAD(&br->port_list);
 450         INIT_HLIST_HEAD(&br->fdb_list);
 451         INIT_HLIST_HEAD(&br->frame_type_list);
 452 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 453         INIT_HLIST_HEAD(&br->mrp_list);
 454 #endif
 455 #if IS_ENABLED(CONFIG_BRIDGE_CFM)
 456         INIT_HLIST_HEAD(&br->mep_list);
 457 #endif
 458         spin_lock_init(&br->hash_lock);
 459
 460         br->bridge_id.prio[0] = 0x80;
 461         br->bridge_id.prio[1] = 0x00;
 462
 463         ether_addr_copy(br->group_addr, eth_stp_addr);
 464
 465         br->stp_enabled = BR_NO_STP;
 466         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 467         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 468
 469         br->designated_root = br->bridge_id;
 470         br->bridge_max_age = br->max_age = 20 * HZ;
 471         br->bridge_hello_time = br->hello_time = 2 * HZ;
 472         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 473         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 474         dev->max_mtu = ETH_MAX_MTU;
 475
 476         br_netfilter_rtable_init(br);
 477         br_stp_timer_init(br);
 478         br_multicast_init(br);
 479         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 480 }