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         u16 vid = 0;
  38
  39         memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
  40
  41         rcu_read_lock();
  42         nf_ops = rcu_dereference(nf_br_ops);
  43         if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
  44                 rcu_read_unlock();
  45                 return NETDEV_TX_OK;
  46         }
  47
  48         u64_stats_update_begin(&brstats->syncp);
  49         brstats->tx_packets++;
  50         brstats->tx_bytes += skb->len;
  51         u64_stats_update_end(&brstats->syncp);
  52
  53         br_switchdev_frame_unmark(skb);
  54         BR_INPUT_SKB_CB(skb)->brdev = dev;
  55         BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
  56
  57         skb_reset_mac_header(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_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(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 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         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 123         if (!br->stats)
 124                 return -ENOMEM;
 125
 126         err = br_fdb_hash_init(br);
 127         if (err) {
 128                 free_percpu(br->stats);
 129                 return err;
 130         }
 131
 132         err = br_mdb_hash_init(br);
 133         if (err) {
 134                 free_percpu(br->stats);
 135                 br_fdb_hash_fini(br);
 136                 return err;
 137         }
 138
 139         err = br_vlan_init(br);
 140         if (err) {
 141                 free_percpu(br->stats);
 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(br->stats);
 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(br->stats);
 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         return 0;
 181 }
 182
 183 static void br_dev_set_multicast_list(struct net_device *dev)
 184 {
 185 }
 186
 187 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 188 {
 189         if (change & IFF_PROMISC)
 190                 br_manage_promisc(netdev_priv(dev));
 191 }
 192
 193 static int br_dev_stop(struct net_device *dev)
 194 {
 195         struct net_bridge *br = netdev_priv(dev);
 196
 197         br_stp_disable_bridge(br);
 198         br_multicast_stop(br);
 199
 200         netif_stop_queue(dev);
 201
 202         return 0;
 203 }
 204
 205 static void br_get_stats64(struct net_device *dev,
 206                            struct rtnl_link_stats64 *stats)
 207 {
 208         struct net_bridge *br = netdev_priv(dev);
 209
 210         dev_fetch_sw_netstats(stats, br->stats);
 211 }
 212
 213 static int br_change_mtu(struct net_device *dev, int new_mtu)
 214 {
 215         struct net_bridge *br = netdev_priv(dev);
 216
 217         dev->mtu = new_mtu;
 218
 219         /* this flag will be cleared if the MTU was automatically adjusted */
 220         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 221 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 222         /* remember the MTU in the rtable for PMTU */
 223         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 224 #endif
 225
 226         return 0;
 227 }
 228
 229 /* Allow setting mac address to any valid ethernet address. */
 230 static int br_set_mac_address(struct net_device *dev, void *p)
 231 {
 232         struct net_bridge *br = netdev_priv(dev);
 233         struct sockaddr *addr = p;
 234
 235         if (!is_valid_ether_addr(addr->sa_data))
 236                 return -EADDRNOTAVAIL;
 237
 238         /* dev_set_mac_addr() can be called by a master device on bridge's
 239          * NETDEV_UNREGISTER, but since it's being destroyed do nothing
 240          */
 241         if (dev->reg_state != NETREG_REGISTERED)
 242                 return -EBUSY;
 243
 244         spin_lock_bh(&br->lock);
 245         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 246                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 247                 br_stp_change_bridge_id(br, addr->sa_data);
 248         }
 249         spin_unlock_bh(&br->lock);
 250
 251         return 0;
 252 }
 253
 254 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 255 {
 256         strlcpy(info->driver, "bridge", sizeof(info->driver));
 257         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 258         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 259         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 260 }
 261
 262 static int br_get_link_ksettings(struct net_device *dev,
 263                                  struct ethtool_link_ksettings *cmd)
 264 {
 265         struct net_bridge *br = netdev_priv(dev);
 266         struct net_bridge_port *p;
 267
 268         cmd->base.duplex = DUPLEX_UNKNOWN;
 269         cmd->base.port = PORT_OTHER;
 270         cmd->base.speed = SPEED_UNKNOWN;
 271
 272         list_for_each_entry(p, &br->port_list, list) {
 273                 struct ethtool_link_ksettings ecmd;
 274                 struct net_device *pdev = p->dev;
 275
 276                 if (!netif_running(pdev) || !netif_oper_up(pdev))
 277                         continue;
 278
 279                 if (__ethtool_get_link_ksettings(pdev, &ecmd))
 280                         continue;
 281
 282                 if (ecmd.base.speed == (__u32)SPEED_UNKNOWN)
 283                         continue;
 284
 285                 if (cmd->base.speed == (__u32)SPEED_UNKNOWN ||
 286                     cmd->base.speed < ecmd.base.speed)
 287                         cmd->base.speed = ecmd.base.speed;
 288         }
 289
 290         return 0;
 291 }
 292
 293 static netdev_features_t br_fix_features(struct net_device *dev,
 294         netdev_features_t features)
 295 {
 296         struct net_bridge *br = netdev_priv(dev);
 297
 298         return br_features_recompute(br, features);
 299 }
 300
 301 #ifdef CONFIG_NET_POLL_CONTROLLER
 302 static void br_poll_controller(struct net_device *br_dev)
 303 {
 304 }
 305
 306 static void br_netpoll_cleanup(struct net_device *dev)
 307 {
 308         struct net_bridge *br = netdev_priv(dev);
 309         struct net_bridge_port *p;
 310
 311         list_for_each_entry(p, &br->port_list, list)
 312                 br_netpoll_disable(p);
 313 }
 314
 315 static int __br_netpoll_enable(struct net_bridge_port *p)
 316 {
 317         struct netpoll *np;
 318         int err;
 319
 320         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 321         if (!np)
 322                 return -ENOMEM;
 323
 324         err = __netpoll_setup(np, p->dev);
 325         if (err) {
 326                 kfree(np);
 327                 return err;
 328         }
 329
 330         p->np = np;
 331         return err;
 332 }
 333
 334 int br_netpoll_enable(struct net_bridge_port *p)
 335 {
 336         if (!p->br->dev->npinfo)
 337                 return 0;
 338
 339         return __br_netpoll_enable(p);
 340 }
 341
 342 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 343 {
 344         struct net_bridge *br = netdev_priv(dev);
 345         struct net_bridge_port *p;
 346         int err = 0;
 347
 348         list_for_each_entry(p, &br->port_list, list) {
 349                 if (!p->dev)
 350                         continue;
 351                 err = __br_netpoll_enable(p);
 352                 if (err)
 353                         goto fail;
 354         }
 355
 356 out:
 357         return err;
 358
 359 fail:
 360         br_netpoll_cleanup(dev);
 361         goto out;
 362 }
 363
 364 void br_netpoll_disable(struct net_bridge_port *p)
 365 {
 366         struct netpoll *np = p->np;
 367
 368         if (!np)
 369                 return;
 370
 371         p->np = NULL;
 372
 373         __netpoll_free(np);
 374 }
 375
 376 #endif
 377
 378 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 379                         struct netlink_ext_ack *extack)
 380
 381 {
 382         struct net_bridge *br = netdev_priv(dev);
 383
 384         return br_add_if(br, slave_dev, extack);
 385 }
 386
 387 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 388 {
 389         struct net_bridge *br = netdev_priv(dev);
 390
 391         return br_del_if(br, slave_dev);
 392 }
 393
 394 static const struct ethtool_ops br_ethtool_ops = {
 395         .get_drvinfo             = br_getinfo,
 396         .get_link                = ethtool_op_get_link,
 397         .get_link_ksettings      = br_get_link_ksettings,
 398 };
 399
 400 static const struct net_device_ops br_netdev_ops = {
 401         .ndo_open                = br_dev_open,
 402         .ndo_stop                = br_dev_stop,
 403         .ndo_init                = br_dev_init,
 404         .ndo_uninit              = br_dev_uninit,
 405         .ndo_start_xmit          = br_dev_xmit,
 406         .ndo_get_stats64         = br_get_stats64,
 407         .ndo_set_mac_address     = br_set_mac_address,
 408         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 409         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 410         .ndo_change_mtu          = br_change_mtu,
 411         .ndo_do_ioctl            = br_dev_ioctl,
 412 #ifdef CONFIG_NET_POLL_CONTROLLER
 413         .ndo_netpoll_setup       = br_netpoll_setup,
 414         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 415         .ndo_poll_controller     = br_poll_controller,
 416 #endif
 417         .ndo_add_slave           = br_add_slave,
 418         .ndo_del_slave           = br_del_slave,
 419         .ndo_fix_features        = br_fix_features,
 420         .ndo_fdb_add             = br_fdb_add,
 421         .ndo_fdb_del             = br_fdb_delete,
 422         .ndo_fdb_dump            = br_fdb_dump,
 423         .ndo_fdb_get             = br_fdb_get,
 424         .ndo_bridge_getlink      = br_getlink,
 425         .ndo_bridge_setlink      = br_setlink,
 426         .ndo_bridge_dellink      = br_dellink,
 427         .ndo_features_check      = passthru_features_check,
 428 };
 429
 430 static struct device_type br_type = {
 431         .name   = "bridge",
 432 };
 433
 434 void br_dev_setup(struct net_device *dev)
 435 {
 436         struct net_bridge *br = netdev_priv(dev);
 437
 438         eth_hw_addr_random(dev);
 439         ether_setup(dev);
 440
 441         dev->netdev_ops = &br_netdev_ops;
 442         dev->needs_free_netdev = true;
 443         dev->ethtool_ops = &br_ethtool_ops;
 444         SET_NETDEV_DEVTYPE(dev, &br_type);
 445         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 446
 447         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 448                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 449         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 450                            NETIF_F_HW_VLAN_STAG_TX;
 451         dev->vlan_features = COMMON_FEATURES;
 452
 453         br->dev = dev;
 454         spin_lock_init(&br->lock);
 455         INIT_LIST_HEAD(&br->port_list);
 456         INIT_HLIST_HEAD(&br->fdb_list);
 457 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 458         INIT_LIST_HEAD(&br->mrp_list);
 459 #endif
 460         spin_lock_init(&br->hash_lock);
 461
 462         br->bridge_id.prio[0] = 0x80;
 463         br->bridge_id.prio[1] = 0x00;
 464
 465         ether_addr_copy(br->group_addr, eth_stp_addr);
 466
 467         br->stp_enabled = BR_NO_STP;
 468         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 469         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 470
 471         br->designated_root = br->bridge_id;
 472         br->bridge_max_age = br->max_age = 20 * HZ;
 473         br->bridge_hello_time = br->hello_time = 2 * HZ;
 474         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 475         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 476         dev->max_mtu = ETH_MAX_MTU;
 477
 478         br_netfilter_rtable_init(br);
 479         br_stp_timer_init(br);
 480         br_multicast_init(br);
 481         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 482 }