net/bridge/br_device.c

   1 /*
   2  *      Device handling code
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <buytenh@gnu.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/netpoll.h>
  17 #include <linux/etherdevice.h>
  18 #include <linux/ethtool.h>
  19 #include <linux/list.h>
  20 #include <linux/netfilter_bridge.h>
  21
  22 #include <linux/uaccess.h>
  23 #include "br_private.h"
  24
  25 #define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \
  26                          NETIF_F_GSO_MASK | NETIF_F_HW_CSUM)
  27
  28 const struct nf_br_ops __rcu *nf_br_ops __read_mostly;
  29 EXPORT_SYMBOL_GPL(nf_br_ops);
  30
  31 static struct lock_class_key bridge_netdev_addr_lock_key;
  32
  33 /* net device transmit always called with BH disabled */
  34 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
  35 {
  36         struct net_bridge *br = netdev_priv(dev);
  37         const unsigned char *dest = skb->data;
  38         struct net_bridge_fdb_entry *dst;
  39         struct net_bridge_mdb_entry *mdst;
  40         struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);
  41         const struct nf_br_ops *nf_ops;
  42         u16 vid = 0;
  43
  44         rcu_read_lock();
  45         nf_ops = rcu_dereference(nf_br_ops);
  46         if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
  47                 rcu_read_unlock();
  48                 return NETDEV_TX_OK;
  49         }
  50
  51         u64_stats_update_begin(&brstats->syncp);
  52         brstats->tx_packets++;
  53         brstats->tx_bytes += skb->len;
  54         u64_stats_update_end(&brstats->syncp);
  55
  56         BR_INPUT_SKB_CB(skb)->brdev = dev;
  57
  58         skb_reset_mac_header(skb);
  59         skb_pull(skb, ETH_HLEN);
  60
  61         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid))
  62                 goto out;
  63
  64         if (is_broadcast_ether_addr(dest)) {
  65                 br_flood(br, skb, BR_PKT_BROADCAST, false, true);
  66         } else if (is_multicast_ether_addr(dest)) {
  67                 if (unlikely(netpoll_tx_running(dev))) {
  68                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  69                         goto out;
  70                 }
  71                 if (br_multicast_rcv(br, NULL, skb, vid)) {
  72                         kfree_skb(skb);
  73                         goto out;
  74                 }
  75
  76                 mdst = br_mdb_get(br, skb, vid);
  77                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
  78                     br_multicast_querier_exists(br, eth_hdr(skb)))
  79                         br_multicast_flood(mdst, skb, false, true);
  80                 else
  81                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  82         } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
  83                 br_forward(dst->dst, skb, false, true);
  84         } else {
  85                 br_flood(br, skb, BR_PKT_UNICAST, false, true);
  86         }
  87 out:
  88         rcu_read_unlock();
  89         return NETDEV_TX_OK;
  90 }
  91
  92 static void br_set_lockdep_class(struct net_device *dev)
  93 {
  94         lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key);
  95 }
  96
  97 static int br_dev_init(struct net_device *dev)
  98 {
  99         struct net_bridge *br = netdev_priv(dev);
 100         int err;
 101
 102         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 103         if (!br->stats)
 104                 return -ENOMEM;
 105
 106         err = br_vlan_init(br);
 107         if (err) {
 108                 free_percpu(br->stats);
 109                 return err;
 110         }
 111
 112         err = br_multicast_init_stats(br);
 113         if (err) {
 114                 free_percpu(br->stats);
 115                 br_vlan_flush(br);
 116         }
 117         br_set_lockdep_class(dev);
 118
 119         return err;
 120 }
 121
 122 static int br_dev_open(struct net_device *dev)
 123 {
 124         struct net_bridge *br = netdev_priv(dev);
 125
 126         netdev_update_features(dev);
 127         netif_start_queue(dev);
 128         br_stp_enable_bridge(br);
 129         br_multicast_open(br);
 130
 131         return 0;
 132 }
 133
 134 static void br_dev_set_multicast_list(struct net_device *dev)
 135 {
 136 }
 137
 138 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 139 {
 140         if (change & IFF_PROMISC)
 141                 br_manage_promisc(netdev_priv(dev));
 142 }
 143
 144 static int br_dev_stop(struct net_device *dev)
 145 {
 146         struct net_bridge *br = netdev_priv(dev);
 147
 148         br_stp_disable_bridge(br);
 149         br_multicast_stop(br);
 150
 151         netif_stop_queue(dev);
 152
 153         return 0;
 154 }
 155
 156 static void br_get_stats64(struct net_device *dev,
 157                            struct rtnl_link_stats64 *stats)
 158 {
 159         struct net_bridge *br = netdev_priv(dev);
 160         struct pcpu_sw_netstats tmp, sum = { 0 };
 161         unsigned int cpu;
 162
 163         for_each_possible_cpu(cpu) {
 164                 unsigned int start;
 165                 const struct pcpu_sw_netstats *bstats
 166                         = per_cpu_ptr(br->stats, cpu);
 167                 do {
 168                         start = u64_stats_fetch_begin_irq(&bstats->syncp);
 169                         memcpy(&tmp, bstats, sizeof(tmp));
 170                 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
 171                 sum.tx_bytes   += tmp.tx_bytes;
 172                 sum.tx_packets += tmp.tx_packets;
 173                 sum.rx_bytes   += tmp.rx_bytes;
 174                 sum.rx_packets += tmp.rx_packets;
 175         }
 176
 177         stats->tx_bytes   = sum.tx_bytes;
 178         stats->tx_packets = sum.tx_packets;
 179         stats->rx_bytes   = sum.rx_bytes;
 180         stats->rx_packets = sum.rx_packets;
 181 }
 182
 183 static int br_change_mtu(struct net_device *dev, int new_mtu)
 184 {
 185         struct net_bridge *br = netdev_priv(dev);
 186         if (new_mtu > br_min_mtu(br))
 187                 return -EINVAL;
 188
 189         dev->mtu = new_mtu;
 190
 191 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 192         /* remember the MTU in the rtable for PMTU */
 193         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 194 #endif
 195
 196         return 0;
 197 }
 198
 199 /* Allow setting mac address to any valid ethernet address. */
 200 static int br_set_mac_address(struct net_device *dev, void *p)
 201 {
 202         struct net_bridge *br = netdev_priv(dev);
 203         struct sockaddr *addr = p;
 204
 205         if (!is_valid_ether_addr(addr->sa_data))
 206                 return -EADDRNOTAVAIL;
 207
 208         spin_lock_bh(&br->lock);
 209         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 210                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 211                 br_stp_change_bridge_id(br, addr->sa_data);
 212         }
 213         spin_unlock_bh(&br->lock);
 214
 215         return 0;
 216 }
 217
 218 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 219 {
 220         strlcpy(info->driver, "bridge", sizeof(info->driver));
 221         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 222         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 223         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 224 }
 225
 226 static netdev_features_t br_fix_features(struct net_device *dev,
 227         netdev_features_t features)
 228 {
 229         struct net_bridge *br = netdev_priv(dev);
 230
 231         return br_features_recompute(br, features);
 232 }
 233
 234 #ifdef CONFIG_NET_POLL_CONTROLLER
 235 static void br_poll_controller(struct net_device *br_dev)
 236 {
 237 }
 238
 239 static void br_netpoll_cleanup(struct net_device *dev)
 240 {
 241         struct net_bridge *br = netdev_priv(dev);
 242         struct net_bridge_port *p;
 243
 244         list_for_each_entry(p, &br->port_list, list)
 245                 br_netpoll_disable(p);
 246 }
 247
 248 static int __br_netpoll_enable(struct net_bridge_port *p)
 249 {
 250         struct netpoll *np;
 251         int err;
 252
 253         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 254         if (!np)
 255                 return -ENOMEM;
 256
 257         err = __netpoll_setup(np, p->dev);
 258         if (err) {
 259                 kfree(np);
 260                 return err;
 261         }
 262
 263         p->np = np;
 264         return err;
 265 }
 266
 267 int br_netpoll_enable(struct net_bridge_port *p)
 268 {
 269         if (!p->br->dev->npinfo)
 270                 return 0;
 271
 272         return __br_netpoll_enable(p);
 273 }
 274
 275 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 276 {
 277         struct net_bridge *br = netdev_priv(dev);
 278         struct net_bridge_port *p;
 279         int err = 0;
 280
 281         list_for_each_entry(p, &br->port_list, list) {
 282                 if (!p->dev)
 283                         continue;
 284                 err = __br_netpoll_enable(p);
 285                 if (err)
 286                         goto fail;
 287         }
 288
 289 out:
 290         return err;
 291
 292 fail:
 293         br_netpoll_cleanup(dev);
 294         goto out;
 295 }
 296
 297 void br_netpoll_disable(struct net_bridge_port *p)
 298 {
 299         struct netpoll *np = p->np;
 300
 301         if (!np)
 302                 return;
 303
 304         p->np = NULL;
 305
 306         __netpoll_free_async(np);
 307 }
 308
 309 #endif
 310
 311 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 312
 313 {
 314         struct net_bridge *br = netdev_priv(dev);
 315
 316         return br_add_if(br, slave_dev);
 317 }
 318
 319 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 320 {
 321         struct net_bridge *br = netdev_priv(dev);
 322
 323         return br_del_if(br, slave_dev);
 324 }
 325
 326 static const struct ethtool_ops br_ethtool_ops = {
 327         .get_drvinfo    = br_getinfo,
 328         .get_link       = ethtool_op_get_link,
 329 };
 330
 331 static const struct net_device_ops br_netdev_ops = {
 332         .ndo_open                = br_dev_open,
 333         .ndo_stop                = br_dev_stop,
 334         .ndo_init                = br_dev_init,
 335         .ndo_start_xmit          = br_dev_xmit,
 336         .ndo_get_stats64         = br_get_stats64,
 337         .ndo_set_mac_address     = br_set_mac_address,
 338         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 339         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 340         .ndo_change_mtu          = br_change_mtu,
 341         .ndo_do_ioctl            = br_dev_ioctl,
 342 #ifdef CONFIG_NET_POLL_CONTROLLER
 343         .ndo_netpoll_setup       = br_netpoll_setup,
 344         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 345         .ndo_poll_controller     = br_poll_controller,
 346 #endif
 347         .ndo_add_slave           = br_add_slave,
 348         .ndo_del_slave           = br_del_slave,
 349         .ndo_fix_features        = br_fix_features,
 350         .ndo_fdb_add             = br_fdb_add,
 351         .ndo_fdb_del             = br_fdb_delete,
 352         .ndo_fdb_dump            = br_fdb_dump,
 353         .ndo_bridge_getlink      = br_getlink,
 354         .ndo_bridge_setlink      = br_setlink,
 355         .ndo_bridge_dellink      = br_dellink,
 356         .ndo_features_check      = passthru_features_check,
 357 };
 358
 359 static void br_dev_free(struct net_device *dev)
 360 {
 361         struct net_bridge *br = netdev_priv(dev);
 362
 363         free_percpu(br->stats);
 364         free_netdev(dev);
 365 }
 366
 367 static struct device_type br_type = {
 368         .name   = "bridge",
 369 };
 370
 371 void br_dev_setup(struct net_device *dev)
 372 {
 373         struct net_bridge *br = netdev_priv(dev);
 374
 375         eth_hw_addr_random(dev);
 376         ether_setup(dev);
 377
 378         dev->netdev_ops = &br_netdev_ops;
 379         dev->destructor = br_dev_free;
 380         dev->ethtool_ops = &br_ethtool_ops;
 381         SET_NETDEV_DEVTYPE(dev, &br_type);
 382         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 383
 384         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 385                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 386         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 387                            NETIF_F_HW_VLAN_STAG_TX;
 388         dev->vlan_features = COMMON_FEATURES;
 389
 390         br->dev = dev;
 391         spin_lock_init(&br->lock);
 392         INIT_LIST_HEAD(&br->port_list);
 393         spin_lock_init(&br->hash_lock);
 394
 395         br->bridge_id.prio[0] = 0x80;
 396         br->bridge_id.prio[1] = 0x00;
 397
 398         ether_addr_copy(br->group_addr, eth_reserved_addr_base);
 399
 400         br->stp_enabled = BR_NO_STP;
 401         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 402         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 403
 404         br->designated_root = br->bridge_id;
 405         br->bridge_max_age = br->max_age = 20 * HZ;
 406         br->bridge_hello_time = br->hello_time = 2 * HZ;
 407         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 408         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 409         dev->max_mtu = ETH_MAX_MTU;
 410
 411         br_netfilter_rtable_init(br);
 412         br_stp_timer_init(br);
 413         br_multicast_init(br);
 414         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 415 }