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