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         const unsigned char *dest;
  36         struct ethhdr *eth;
  37         u16 vid = 0;
  38
  39         rcu_read_lock();
  40         nf_ops = rcu_dereference(nf_br_ops);
  41         if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
  42                 rcu_read_unlock();
  43                 return NETDEV_TX_OK;
  44         }
  45
  46         u64_stats_update_begin(&brstats->syncp);
  47         brstats->tx_packets++;
  48         brstats->tx_bytes += skb->len;
  49         u64_stats_update_end(&brstats->syncp);
  50
  51         br_switchdev_frame_unmark(skb);
  52         BR_INPUT_SKB_CB(skb)->brdev = dev;
  53         BR_INPUT_SKB_CB(skb)->frag_max_size = 0;
  54
  55         skb_reset_mac_header(skb);
  56         eth = eth_hdr(skb);
  57         skb_pull(skb, ETH_HLEN);
  58
  59         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid))
  60                 goto out;
  61
  62         if (IS_ENABLED(CONFIG_INET) &&
  63             (eth->h_proto == htons(ETH_P_ARP) ||
  64              eth->h_proto == htons(ETH_P_RARP)) &&
  65             br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) {
  66                 br_do_proxy_suppress_arp(skb, br, vid, NULL);
  67         } else if (IS_ENABLED(CONFIG_IPV6) &&
  68                    skb->protocol == htons(ETH_P_IPV6) &&
  69                    br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) &&
  70                    pskb_may_pull(skb, sizeof(struct ipv6hdr) +
  71                                  sizeof(struct nd_msg)) &&
  72                    ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
  73                         struct nd_msg *msg, _msg;
  74
  75                         msg = br_is_nd_neigh_msg(skb, &_msg);
  76                         if (msg)
  77                                 br_do_suppress_nd(skb, br, vid, NULL, msg);
  78         }
  79
  80         dest = eth_hdr(skb)->h_dest;
  81         if (is_broadcast_ether_addr(dest)) {
  82                 br_flood(br, skb, BR_PKT_BROADCAST, false, true);
  83         } else if (is_multicast_ether_addr(dest)) {
  84                 if (unlikely(netpoll_tx_running(dev))) {
  85                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  86                         goto out;
  87                 }
  88                 if (br_multicast_rcv(br, NULL, skb, vid)) {
  89                         kfree_skb(skb);
  90                         goto out;
  91                 }
  92
  93                 mdst = br_mdb_get(br, skb, vid);
  94                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
  95                     br_multicast_querier_exists(br, eth_hdr(skb)))
  96                         br_multicast_flood(mdst, skb, false, true);
  97                 else
  98                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  99         } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
 100                 br_forward(dst->dst, skb, false, true);
 101         } else {
 102                 br_flood(br, skb, BR_PKT_UNICAST, false, true);
 103         }
 104 out:
 105         rcu_read_unlock();
 106         return NETDEV_TX_OK;
 107 }
 108
 109 static int br_dev_init(struct net_device *dev)
 110 {
 111         struct net_bridge *br = netdev_priv(dev);
 112         int err;
 113
 114         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 115         if (!br->stats)
 116                 return -ENOMEM;
 117
 118         err = br_fdb_hash_init(br);
 119         if (err) {
 120                 free_percpu(br->stats);
 121                 return err;
 122         }
 123
 124         err = br_mdb_hash_init(br);
 125         if (err) {
 126                 free_percpu(br->stats);
 127                 br_fdb_hash_fini(br);
 128                 return err;
 129         }
 130
 131         err = br_vlan_init(br);
 132         if (err) {
 133                 free_percpu(br->stats);
 134                 br_mdb_hash_fini(br);
 135                 br_fdb_hash_fini(br);
 136                 return err;
 137         }
 138
 139         err = br_multicast_init_stats(br);
 140         if (err) {
 141                 free_percpu(br->stats);
 142                 br_vlan_flush(br);
 143                 br_mdb_hash_fini(br);
 144                 br_fdb_hash_fini(br);
 145         }
 146
 147         return err;
 148 }
 149
 150 static void br_dev_uninit(struct net_device *dev)
 151 {
 152         struct net_bridge *br = netdev_priv(dev);
 153
 154         br_multicast_dev_del(br);
 155         br_multicast_uninit_stats(br);
 156         br_vlan_flush(br);
 157         br_mdb_hash_fini(br);
 158         br_fdb_hash_fini(br);
 159         free_percpu(br->stats);
 160 }
 161
 162 static int br_dev_open(struct net_device *dev)
 163 {
 164         struct net_bridge *br = netdev_priv(dev);
 165
 166         netdev_update_features(dev);
 167         netif_start_queue(dev);
 168         br_stp_enable_bridge(br);
 169         br_multicast_open(br);
 170
 171         return 0;
 172 }
 173
 174 static void br_dev_set_multicast_list(struct net_device *dev)
 175 {
 176 }
 177
 178 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 179 {
 180         if (change & IFF_PROMISC)
 181                 br_manage_promisc(netdev_priv(dev));
 182 }
 183
 184 static int br_dev_stop(struct net_device *dev)
 185 {
 186         struct net_bridge *br = netdev_priv(dev);
 187
 188         br_stp_disable_bridge(br);
 189         br_multicast_stop(br);
 190
 191         netif_stop_queue(dev);
 192
 193         return 0;
 194 }
 195
 196 static void br_get_stats64(struct net_device *dev,
 197                            struct rtnl_link_stats64 *stats)
 198 {
 199         struct net_bridge *br = netdev_priv(dev);
 200         struct pcpu_sw_netstats tmp, sum = { 0 };
 201         unsigned int cpu;
 202
 203         for_each_possible_cpu(cpu) {
 204                 unsigned int start;
 205                 const struct pcpu_sw_netstats *bstats
 206                         = per_cpu_ptr(br->stats, cpu);
 207                 do {
 208                         start = u64_stats_fetch_begin_irq(&bstats->syncp);
 209                         memcpy(&tmp, bstats, sizeof(tmp));
 210                 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
 211                 sum.tx_bytes   += tmp.tx_bytes;
 212                 sum.tx_packets += tmp.tx_packets;
 213                 sum.rx_bytes   += tmp.rx_bytes;
 214                 sum.rx_packets += tmp.rx_packets;
 215         }
 216
 217         stats->tx_bytes   = sum.tx_bytes;
 218         stats->tx_packets = sum.tx_packets;
 219         stats->rx_bytes   = sum.rx_bytes;
 220         stats->rx_packets = sum.rx_packets;
 221 }
 222
 223 static int br_change_mtu(struct net_device *dev, int new_mtu)
 224 {
 225         struct net_bridge *br = netdev_priv(dev);
 226
 227         dev->mtu = new_mtu;
 228
 229         /* this flag will be cleared if the MTU was automatically adjusted */
 230         br_opt_toggle(br, BROPT_MTU_SET_BY_USER, true);
 231 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 232         /* remember the MTU in the rtable for PMTU */
 233         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 234 #endif
 235
 236         return 0;
 237 }
 238
 239 /* Allow setting mac address to any valid ethernet address. */
 240 static int br_set_mac_address(struct net_device *dev, void *p)
 241 {
 242         struct net_bridge *br = netdev_priv(dev);
 243         struct sockaddr *addr = p;
 244
 245         if (!is_valid_ether_addr(addr->sa_data))
 246                 return -EADDRNOTAVAIL;
 247
 248         spin_lock_bh(&br->lock);
 249         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 250                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 251                 br_stp_change_bridge_id(br, addr->sa_data);
 252         }
 253         spin_unlock_bh(&br->lock);
 254
 255         return 0;
 256 }
 257
 258 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 259 {
 260         strlcpy(info->driver, "bridge", sizeof(info->driver));
 261         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 262         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 263         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 264 }
 265
 266 static netdev_features_t br_fix_features(struct net_device *dev,
 267         netdev_features_t features)
 268 {
 269         struct net_bridge *br = netdev_priv(dev);
 270
 271         return br_features_recompute(br, features);
 272 }
 273
 274 #ifdef CONFIG_NET_POLL_CONTROLLER
 275 static void br_poll_controller(struct net_device *br_dev)
 276 {
 277 }
 278
 279 static void br_netpoll_cleanup(struct net_device *dev)
 280 {
 281         struct net_bridge *br = netdev_priv(dev);
 282         struct net_bridge_port *p;
 283
 284         list_for_each_entry(p, &br->port_list, list)
 285                 br_netpoll_disable(p);
 286 }
 287
 288 static int __br_netpoll_enable(struct net_bridge_port *p)
 289 {
 290         struct netpoll *np;
 291         int err;
 292
 293         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 294         if (!np)
 295                 return -ENOMEM;
 296
 297         err = __netpoll_setup(np, p->dev);
 298         if (err) {
 299                 kfree(np);
 300                 return err;
 301         }
 302
 303         p->np = np;
 304         return err;
 305 }
 306
 307 int br_netpoll_enable(struct net_bridge_port *p)
 308 {
 309         if (!p->br->dev->npinfo)
 310                 return 0;
 311
 312         return __br_netpoll_enable(p);
 313 }
 314
 315 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 316 {
 317         struct net_bridge *br = netdev_priv(dev);
 318         struct net_bridge_port *p;
 319         int err = 0;
 320
 321         list_for_each_entry(p, &br->port_list, list) {
 322                 if (!p->dev)
 323                         continue;
 324                 err = __br_netpoll_enable(p);
 325                 if (err)
 326                         goto fail;
 327         }
 328
 329 out:
 330         return err;
 331
 332 fail:
 333         br_netpoll_cleanup(dev);
 334         goto out;
 335 }
 336
 337 void br_netpoll_disable(struct net_bridge_port *p)
 338 {
 339         struct netpoll *np = p->np;
 340
 341         if (!np)
 342                 return;
 343
 344         p->np = NULL;
 345
 346         __netpoll_free(np);
 347 }
 348
 349 #endif
 350
 351 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 352                         struct netlink_ext_ack *extack)
 353
 354 {
 355         struct net_bridge *br = netdev_priv(dev);
 356
 357         return br_add_if(br, slave_dev, extack);
 358 }
 359
 360 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 361 {
 362         struct net_bridge *br = netdev_priv(dev);
 363
 364         return br_del_if(br, slave_dev);
 365 }
 366
 367 static const struct ethtool_ops br_ethtool_ops = {
 368         .get_drvinfo    = br_getinfo,
 369         .get_link       = ethtool_op_get_link,
 370 };
 371
 372 static const struct net_device_ops br_netdev_ops = {
 373         .ndo_open                = br_dev_open,
 374         .ndo_stop                = br_dev_stop,
 375         .ndo_init                = br_dev_init,
 376         .ndo_uninit              = br_dev_uninit,
 377         .ndo_start_xmit          = br_dev_xmit,
 378         .ndo_get_stats64         = br_get_stats64,
 379         .ndo_set_mac_address     = br_set_mac_address,
 380         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 381         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 382         .ndo_change_mtu          = br_change_mtu,
 383         .ndo_do_ioctl            = br_dev_ioctl,
 384 #ifdef CONFIG_NET_POLL_CONTROLLER
 385         .ndo_netpoll_setup       = br_netpoll_setup,
 386         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 387         .ndo_poll_controller     = br_poll_controller,
 388 #endif
 389         .ndo_add_slave           = br_add_slave,
 390         .ndo_del_slave           = br_del_slave,
 391         .ndo_fix_features        = br_fix_features,
 392         .ndo_fdb_add             = br_fdb_add,
 393         .ndo_fdb_del             = br_fdb_delete,
 394         .ndo_fdb_dump            = br_fdb_dump,
 395         .ndo_fdb_get             = br_fdb_get,
 396         .ndo_bridge_getlink      = br_getlink,
 397         .ndo_bridge_setlink      = br_setlink,
 398         .ndo_bridge_dellink      = br_dellink,
 399         .ndo_features_check      = passthru_features_check,
 400 };
 401
 402 static struct device_type br_type = {
 403         .name   = "bridge",
 404 };
 405
 406 void br_dev_setup(struct net_device *dev)
 407 {
 408         struct net_bridge *br = netdev_priv(dev);
 409
 410         eth_hw_addr_random(dev);
 411         ether_setup(dev);
 412
 413         dev->netdev_ops = &br_netdev_ops;
 414         dev->needs_free_netdev = true;
 415         dev->ethtool_ops = &br_ethtool_ops;
 416         SET_NETDEV_DEVTYPE(dev, &br_type);
 417         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 418
 419         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 420                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 421         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 422                            NETIF_F_HW_VLAN_STAG_TX;
 423         dev->vlan_features = COMMON_FEATURES;
 424
 425         br->dev = dev;
 426         spin_lock_init(&br->lock);
 427         INIT_LIST_HEAD(&br->port_list);
 428         INIT_HLIST_HEAD(&br->fdb_list);
 429         spin_lock_init(&br->hash_lock);
 430
 431         br->bridge_id.prio[0] = 0x80;
 432         br->bridge_id.prio[1] = 0x00;
 433
 434         ether_addr_copy(br->group_addr, eth_stp_addr);
 435
 436         br->stp_enabled = BR_NO_STP;
 437         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 438         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 439
 440         br->designated_root = br->bridge_id;
 441         br->bridge_max_age = br->max_age = 20 * HZ;
 442         br->bridge_hello_time = br->hello_time = 2 * HZ;
 443         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 444         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 445         dev->max_mtu = ETH_MAX_MTU;
 446
 447         br_netfilter_rtable_init(br);
 448         br_stp_timer_init(br);
 449         br_multicast_init(br);
 450         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 451 }