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         struct net_bridge_fdb_entry *dst;
  38         struct net_bridge_mdb_entry *mdst;
  39         struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);
  40         const struct nf_br_ops *nf_ops;
  41         const unsigned char *dest;
  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_switchdev_frame_unmark(skb);
  57         BR_INPUT_SKB_CB(skb)->brdev = dev;
  58
  59         skb_reset_mac_header(skb);
  60         skb_pull(skb, ETH_HLEN);
  61
  62         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid))
  63                 goto out;
  64
  65         dest = eth_hdr(skb)->h_dest;
  66         if (is_broadcast_ether_addr(dest)) {
  67                 br_flood(br, skb, BR_PKT_BROADCAST, false, true);
  68         } else if (is_multicast_ether_addr(dest)) {
  69                 if (unlikely(netpoll_tx_running(dev))) {
  70                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  71                         goto out;
  72                 }
  73                 if (br_multicast_rcv(br, NULL, skb, vid)) {
  74                         kfree_skb(skb);
  75                         goto out;
  76                 }
  77
  78                 mdst = br_mdb_get(br, skb, vid);
  79                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
  80                     br_multicast_querier_exists(br, eth_hdr(skb)))
  81                         br_multicast_flood(mdst, skb, false, true);
  82                 else
  83                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  84         } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
  85                 br_forward(dst->dst, skb, false, true);
  86         } else {
  87                 br_flood(br, skb, BR_PKT_UNICAST, false, true);
  88         }
  89 out:
  90         rcu_read_unlock();
  91         return NETDEV_TX_OK;
  92 }
  93
  94 static void br_set_lockdep_class(struct net_device *dev)
  95 {
  96         lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key);
  97 }
  98
  99 static int br_dev_init(struct net_device *dev)
 100 {
 101         struct net_bridge *br = netdev_priv(dev);
 102         int err;
 103
 104         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 105         if (!br->stats)
 106                 return -ENOMEM;
 107
 108         err = br_vlan_init(br);
 109         if (err) {
 110                 free_percpu(br->stats);
 111                 return err;
 112         }
 113
 114         err = br_multicast_init_stats(br);
 115         if (err) {
 116                 free_percpu(br->stats);
 117                 br_vlan_flush(br);
 118         }
 119         br_set_lockdep_class(dev);
 120
 121         return err;
 122 }
 123
 124 static void br_dev_uninit(struct net_device *dev)
 125 {
 126         struct net_bridge *br = netdev_priv(dev);
 127
 128         br_multicast_dev_del(br);
 129         br_multicast_uninit_stats(br);
 130         br_vlan_flush(br);
 131         free_percpu(br->stats);
 132 }
 133
 134 static int br_dev_open(struct net_device *dev)
 135 {
 136         struct net_bridge *br = netdev_priv(dev);
 137
 138         netdev_update_features(dev);
 139         netif_start_queue(dev);
 140         br_stp_enable_bridge(br);
 141         br_multicast_open(br);
 142
 143         return 0;
 144 }
 145
 146 static void br_dev_set_multicast_list(struct net_device *dev)
 147 {
 148 }
 149
 150 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 151 {
 152         if (change & IFF_PROMISC)
 153                 br_manage_promisc(netdev_priv(dev));
 154 }
 155
 156 static int br_dev_stop(struct net_device *dev)
 157 {
 158         struct net_bridge *br = netdev_priv(dev);
 159
 160         br_stp_disable_bridge(br);
 161         br_multicast_stop(br);
 162
 163         netif_stop_queue(dev);
 164
 165         return 0;
 166 }
 167
 168 static void br_get_stats64(struct net_device *dev,
 169                            struct rtnl_link_stats64 *stats)
 170 {
 171         struct net_bridge *br = netdev_priv(dev);
 172         struct pcpu_sw_netstats tmp, sum = { 0 };
 173         unsigned int cpu;
 174
 175         for_each_possible_cpu(cpu) {
 176                 unsigned int start;
 177                 const struct pcpu_sw_netstats *bstats
 178                         = per_cpu_ptr(br->stats, cpu);
 179                 do {
 180                         start = u64_stats_fetch_begin_irq(&bstats->syncp);
 181                         memcpy(&tmp, bstats, sizeof(tmp));
 182                 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
 183                 sum.tx_bytes   += tmp.tx_bytes;
 184                 sum.tx_packets += tmp.tx_packets;
 185                 sum.rx_bytes   += tmp.rx_bytes;
 186                 sum.rx_packets += tmp.rx_packets;
 187         }
 188
 189         netdev_stats_to_stats64(stats, &dev->stats);
 190         stats->tx_bytes   = sum.tx_bytes;
 191         stats->tx_packets = sum.tx_packets;
 192         stats->rx_bytes   = sum.rx_bytes;
 193         stats->rx_packets = sum.rx_packets;
 194 }
 195
 196 static int br_change_mtu(struct net_device *dev, int new_mtu)
 197 {
 198         struct net_bridge *br = netdev_priv(dev);
 199         if (new_mtu > br_min_mtu(br))
 200                 return -EINVAL;
 201
 202         dev->mtu = new_mtu;
 203
 204 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 205         /* remember the MTU in the rtable for PMTU */
 206         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 207 #endif
 208
 209         return 0;
 210 }
 211
 212 /* Allow setting mac address to any valid ethernet address. */
 213 static int br_set_mac_address(struct net_device *dev, void *p)
 214 {
 215         struct net_bridge *br = netdev_priv(dev);
 216         struct sockaddr *addr = p;
 217
 218         if (!is_valid_ether_addr(addr->sa_data))
 219                 return -EADDRNOTAVAIL;
 220
 221         /* dev_set_mac_addr() can be called by a master device on bridge's
 222          * NETDEV_UNREGISTER, but since it's being destroyed do nothing
 223          */
 224         if (dev->reg_state != NETREG_REGISTERED)
 225                 return -EBUSY;
 226
 227         spin_lock_bh(&br->lock);
 228         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 229                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 230                 br_stp_change_bridge_id(br, addr->sa_data);
 231         }
 232         spin_unlock_bh(&br->lock);
 233
 234         return 0;
 235 }
 236
 237 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 238 {
 239         strlcpy(info->driver, "bridge", sizeof(info->driver));
 240         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 241         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 242         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 243 }
 244
 245 static netdev_features_t br_fix_features(struct net_device *dev,
 246         netdev_features_t features)
 247 {
 248         struct net_bridge *br = netdev_priv(dev);
 249
 250         return br_features_recompute(br, features);
 251 }
 252
 253 #ifdef CONFIG_NET_POLL_CONTROLLER
 254 static void br_poll_controller(struct net_device *br_dev)
 255 {
 256 }
 257
 258 static void br_netpoll_cleanup(struct net_device *dev)
 259 {
 260         struct net_bridge *br = netdev_priv(dev);
 261         struct net_bridge_port *p;
 262
 263         list_for_each_entry(p, &br->port_list, list)
 264                 br_netpoll_disable(p);
 265 }
 266
 267 static int __br_netpoll_enable(struct net_bridge_port *p)
 268 {
 269         struct netpoll *np;
 270         int err;
 271
 272         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 273         if (!np)
 274                 return -ENOMEM;
 275
 276         err = __netpoll_setup(np, p->dev);
 277         if (err) {
 278                 kfree(np);
 279                 return err;
 280         }
 281
 282         p->np = np;
 283         return err;
 284 }
 285
 286 int br_netpoll_enable(struct net_bridge_port *p)
 287 {
 288         if (!p->br->dev->npinfo)
 289                 return 0;
 290
 291         return __br_netpoll_enable(p);
 292 }
 293
 294 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 295 {
 296         struct net_bridge *br = netdev_priv(dev);
 297         struct net_bridge_port *p;
 298         int err = 0;
 299
 300         list_for_each_entry(p, &br->port_list, list) {
 301                 if (!p->dev)
 302                         continue;
 303                 err = __br_netpoll_enable(p);
 304                 if (err)
 305                         goto fail;
 306         }
 307
 308 out:
 309         return err;
 310
 311 fail:
 312         br_netpoll_cleanup(dev);
 313         goto out;
 314 }
 315
 316 void br_netpoll_disable(struct net_bridge_port *p)
 317 {
 318         struct netpoll *np = p->np;
 319
 320         if (!np)
 321                 return;
 322
 323         p->np = NULL;
 324
 325         __netpoll_free_async(np);
 326 }
 327
 328 #endif
 329
 330 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 331
 332 {
 333         struct net_bridge *br = netdev_priv(dev);
 334
 335         return br_add_if(br, slave_dev);
 336 }
 337
 338 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 339 {
 340         struct net_bridge *br = netdev_priv(dev);
 341
 342         return br_del_if(br, slave_dev);
 343 }
 344
 345 static const struct ethtool_ops br_ethtool_ops = {
 346         .get_drvinfo    = br_getinfo,
 347         .get_link       = ethtool_op_get_link,
 348 };
 349
 350 static const struct net_device_ops br_netdev_ops = {
 351         .ndo_open                = br_dev_open,
 352         .ndo_stop                = br_dev_stop,
 353         .ndo_init                = br_dev_init,
 354         .ndo_uninit              = br_dev_uninit,
 355         .ndo_start_xmit          = br_dev_xmit,
 356         .ndo_get_stats64         = br_get_stats64,
 357         .ndo_set_mac_address     = br_set_mac_address,
 358         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 359         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 360         .ndo_change_mtu          = br_change_mtu,
 361         .ndo_do_ioctl            = br_dev_ioctl,
 362 #ifdef CONFIG_NET_POLL_CONTROLLER
 363         .ndo_netpoll_setup       = br_netpoll_setup,
 364         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 365         .ndo_poll_controller     = br_poll_controller,
 366 #endif
 367         .ndo_add_slave           = br_add_slave,
 368         .ndo_del_slave           = br_del_slave,
 369         .ndo_fix_features        = br_fix_features,
 370         .ndo_fdb_add             = br_fdb_add,
 371         .ndo_fdb_del             = br_fdb_delete,
 372         .ndo_fdb_dump            = br_fdb_dump,
 373         .ndo_bridge_getlink      = br_getlink,
 374         .ndo_bridge_setlink      = br_setlink,
 375         .ndo_bridge_dellink      = br_dellink,
 376         .ndo_features_check      = passthru_features_check,
 377 };
 378
 379 static struct device_type br_type = {
 380         .name   = "bridge",
 381 };
 382
 383 void br_dev_setup(struct net_device *dev)
 384 {
 385         struct net_bridge *br = netdev_priv(dev);
 386
 387         eth_hw_addr_random(dev);
 388         ether_setup(dev);
 389
 390         dev->netdev_ops = &br_netdev_ops;
 391         dev->needs_free_netdev = true;
 392         dev->ethtool_ops = &br_ethtool_ops;
 393         SET_NETDEV_DEVTYPE(dev, &br_type);
 394         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 395
 396         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 397                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 398         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 399                            NETIF_F_HW_VLAN_STAG_TX;
 400         dev->vlan_features = COMMON_FEATURES;
 401
 402         br->dev = dev;
 403         spin_lock_init(&br->lock);
 404         INIT_LIST_HEAD(&br->port_list);
 405         spin_lock_init(&br->hash_lock);
 406
 407         br->bridge_id.prio[0] = 0x80;
 408         br->bridge_id.prio[1] = 0x00;
 409
 410         ether_addr_copy(br->group_addr, eth_reserved_addr_base);
 411
 412         br->stp_enabled = BR_NO_STP;
 413         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 414         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 415
 416         br->designated_root = br->bridge_id;
 417         br->bridge_max_age = br->max_age = 20 * HZ;
 418         br->bridge_hello_time = br->hello_time = 2 * HZ;
 419         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 420         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 421         dev->max_mtu = ETH_MAX_MTU;
 422
 423         br_netfilter_rtable_init(br);
 424         br_stp_timer_init(br);
 425         br_multicast_init(br);
 426         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 427 }