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 /* net device transmit always called with BH disabled */
  26 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
  27 {
  28         struct net_bridge *br = netdev_priv(dev);
  29         const unsigned char *dest = skb->data;
  30         struct net_bridge_fdb_entry *dst;
  31         struct net_bridge_mdb_entry *mdst;
  32         struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
  33
  34 #ifdef CONFIG_BRIDGE_NETFILTER
  35         if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
  36                 br_nf_pre_routing_finish_bridge_slow(skb);
  37                 return NETDEV_TX_OK;
  38         }
  39 #endif
  40
  41         u64_stats_update_begin(&brstats->syncp);
  42         brstats->tx_packets++;
  43         brstats->tx_bytes += skb->len;
  44         u64_stats_update_end(&brstats->syncp);
  45
  46         BR_INPUT_SKB_CB(skb)->brdev = dev;
  47
  48         skb_reset_mac_header(skb);
  49         skb_pull(skb, ETH_HLEN);
  50
  51         rcu_read_lock();
  52         if (is_multicast_ether_addr(dest)) {
  53                 if (unlikely(netpoll_tx_running(dev))) {
  54                         br_flood_deliver(br, skb);
  55                         goto out;
  56                 }
  57                 if (br_multicast_rcv(br, NULL, skb)) {
  58                         kfree_skb(skb);
  59                         goto out;
  60                 }
  61
  62                 mdst = br_mdb_get(br, skb);
  63                 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb))
  64                         br_multicast_deliver(mdst, skb);
  65                 else
  66                         br_flood_deliver(br, skb);
  67         } else if ((dst = __br_fdb_get(br, dest)) != NULL)
  68                 br_deliver(dst->dst, skb);
  69         else
  70                 br_flood_deliver(br, skb);
  71
  72 out:
  73         rcu_read_unlock();
  74         return NETDEV_TX_OK;
  75 }
  76
  77 static int br_dev_init(struct net_device *dev)
  78 {
  79         struct net_bridge *br = netdev_priv(dev);
  80
  81         br->stats = alloc_percpu(struct br_cpu_netstats);
  82         if (!br->stats)
  83                 return -ENOMEM;
  84
  85         return 0;
  86 }
  87
  88 static int br_dev_open(struct net_device *dev)
  89 {
  90         struct net_bridge *br = netdev_priv(dev);
  91
  92         netif_carrier_off(dev);
  93
  94         br_features_recompute(br);
  95         netif_start_queue(dev);
  96         br_stp_enable_bridge(br);
  97         br_multicast_open(br);
  98
  99         return 0;
 100 }
 101
 102 static void br_dev_set_multicast_list(struct net_device *dev)
 103 {
 104 }
 105
 106 static int br_dev_stop(struct net_device *dev)
 107 {
 108         struct net_bridge *br = netdev_priv(dev);
 109
 110         netif_carrier_off(dev);
 111
 112         br_stp_disable_bridge(br);
 113         br_multicast_stop(br);
 114
 115         netif_stop_queue(dev);
 116
 117         return 0;
 118 }
 119
 120 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 121                                                 struct rtnl_link_stats64 *stats)
 122 {
 123         struct net_bridge *br = netdev_priv(dev);
 124         struct br_cpu_netstats tmp, sum = { 0 };
 125         unsigned int cpu;
 126
 127         for_each_possible_cpu(cpu) {
 128                 unsigned int start;
 129                 const struct br_cpu_netstats *bstats
 130                         = per_cpu_ptr(br->stats, cpu);
 131                 do {
 132                         start = u64_stats_fetch_begin(&bstats->syncp);
 133                         memcpy(&tmp, bstats, sizeof(tmp));
 134                 } while (u64_stats_fetch_retry(&bstats->syncp, start));
 135                 sum.tx_bytes   += tmp.tx_bytes;
 136                 sum.tx_packets += tmp.tx_packets;
 137                 sum.rx_bytes   += tmp.rx_bytes;
 138                 sum.rx_packets += tmp.rx_packets;
 139         }
 140
 141         stats->tx_bytes   = sum.tx_bytes;
 142         stats->tx_packets = sum.tx_packets;
 143         stats->rx_bytes   = sum.rx_bytes;
 144         stats->rx_packets = sum.rx_packets;
 145
 146         return stats;
 147 }
 148
 149 static int br_change_mtu(struct net_device *dev, int new_mtu)
 150 {
 151         struct net_bridge *br = netdev_priv(dev);
 152         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 153                 return -EINVAL;
 154
 155         dev->mtu = new_mtu;
 156
 157 #ifdef CONFIG_BRIDGE_NETFILTER
 158         /* remember the MTU in the rtable for PMTU */
 159         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 160 #endif
 161
 162         return 0;
 163 }
 164
 165 /* Allow setting mac address to any valid ethernet address. */
 166 static int br_set_mac_address(struct net_device *dev, void *p)
 167 {
 168         struct net_bridge *br = netdev_priv(dev);
 169         struct sockaddr *addr = p;
 170
 171         if (!is_valid_ether_addr(addr->sa_data))
 172                 return -EINVAL;
 173
 174         spin_lock_bh(&br->lock);
 175         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 176         br_stp_change_bridge_id(br, addr->sa_data);
 177         br->flags |= BR_SET_MAC_ADDR;
 178         spin_unlock_bh(&br->lock);
 179
 180         return 0;
 181 }
 182
 183 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 184 {
 185         strcpy(info->driver, "bridge");
 186         strcpy(info->version, BR_VERSION);
 187         strcpy(info->fw_version, "N/A");
 188         strcpy(info->bus_info, "N/A");
 189 }
 190
 191 static int br_set_sg(struct net_device *dev, u32 data)
 192 {
 193         struct net_bridge *br = netdev_priv(dev);
 194
 195         if (data)
 196                 br->feature_mask |= NETIF_F_SG;
 197         else
 198                 br->feature_mask &= ~NETIF_F_SG;
 199
 200         br_features_recompute(br);
 201         return 0;
 202 }
 203
 204 static int br_set_tso(struct net_device *dev, u32 data)
 205 {
 206         struct net_bridge *br = netdev_priv(dev);
 207
 208         if (data)
 209                 br->feature_mask |= NETIF_F_TSO;
 210         else
 211                 br->feature_mask &= ~NETIF_F_TSO;
 212
 213         br_features_recompute(br);
 214         return 0;
 215 }
 216
 217 static int br_set_tx_csum(struct net_device *dev, u32 data)
 218 {
 219         struct net_bridge *br = netdev_priv(dev);
 220
 221         if (data)
 222                 br->feature_mask |= NETIF_F_NO_CSUM;
 223         else
 224                 br->feature_mask &= ~NETIF_F_ALL_CSUM;
 225
 226         br_features_recompute(br);
 227         return 0;
 228 }
 229
 230 static int br_set_flags(struct net_device *netdev, u32 data)
 231 {
 232         return ethtool_op_set_flags(netdev, data, ETH_FLAG_TXVLAN);
 233 }
 234
 235 #ifdef CONFIG_NET_POLL_CONTROLLER
 236 static void br_poll_controller(struct net_device *br_dev)
 237 {
 238 }
 239
 240 static void br_netpoll_cleanup(struct net_device *dev)
 241 {
 242         struct net_bridge *br = netdev_priv(dev);
 243         struct net_bridge_port *p, *n;
 244
 245         list_for_each_entry_safe(p, n, &br->port_list, list) {
 246                 br_netpoll_disable(p);
 247         }
 248 }
 249
 250 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 251 {
 252         struct net_bridge *br = netdev_priv(dev);
 253         struct net_bridge_port *p, *n;
 254         int err = 0;
 255
 256         list_for_each_entry_safe(p, n, &br->port_list, list) {
 257                 if (!p->dev)
 258                         continue;
 259
 260                 err = br_netpoll_enable(p);
 261                 if (err)
 262                         goto fail;
 263         }
 264
 265 out:
 266         return err;
 267
 268 fail:
 269         br_netpoll_cleanup(dev);
 270         goto out;
 271 }
 272
 273 int br_netpoll_enable(struct net_bridge_port *p)
 274 {
 275         struct netpoll *np;
 276         int err = 0;
 277
 278         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 279         err = -ENOMEM;
 280         if (!np)
 281                 goto out;
 282
 283         np->dev = p->dev;
 284
 285         err = __netpoll_setup(np);
 286         if (err) {
 287                 kfree(np);
 288                 goto out;
 289         }
 290
 291         p->np = np;
 292
 293 out:
 294         return err;
 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         /* Wait for transmitting packets to finish before freeing. */
 307         synchronize_rcu_bh();
 308
 309         __netpoll_cleanup(np);
 310         kfree(np);
 311 }
 312
 313 #endif
 314
 315 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 316
 317 {
 318         struct net_bridge *br = netdev_priv(dev);
 319
 320         return br_add_if(br, slave_dev);
 321 }
 322
 323 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 324 {
 325         struct net_bridge *br = netdev_priv(dev);
 326
 327         return br_del_if(br, slave_dev);
 328 }
 329
 330 static const struct ethtool_ops br_ethtool_ops = {
 331         .get_drvinfo    = br_getinfo,
 332         .get_link       = ethtool_op_get_link,
 333         .get_tx_csum    = ethtool_op_get_tx_csum,
 334         .set_tx_csum    = br_set_tx_csum,
 335         .get_sg         = ethtool_op_get_sg,
 336         .set_sg         = br_set_sg,
 337         .get_tso        = ethtool_op_get_tso,
 338         .set_tso        = br_set_tso,
 339         .get_ufo        = ethtool_op_get_ufo,
 340         .set_ufo        = ethtool_op_set_ufo,
 341         .get_flags      = ethtool_op_get_flags,
 342         .set_flags      = br_set_flags,
 343 };
 344
 345 static const struct net_device_ops br_netdev_ops = {
 346         .ndo_open                = br_dev_open,
 347         .ndo_stop                = br_dev_stop,
 348         .ndo_init                = br_dev_init,
 349         .ndo_start_xmit          = br_dev_xmit,
 350         .ndo_get_stats64         = br_get_stats64,
 351         .ndo_set_mac_address     = br_set_mac_address,
 352         .ndo_set_multicast_list  = br_dev_set_multicast_list,
 353         .ndo_change_mtu          = br_change_mtu,
 354         .ndo_do_ioctl            = br_dev_ioctl,
 355 #ifdef CONFIG_NET_POLL_CONTROLLER
 356         .ndo_netpoll_setup       = br_netpoll_setup,
 357         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 358         .ndo_poll_controller     = br_poll_controller,
 359 #endif
 360         .ndo_add_slave           = br_add_slave,
 361         .ndo_del_slave           = br_del_slave,
 362 };
 363
 364 static void br_dev_free(struct net_device *dev)
 365 {
 366         struct net_bridge *br = netdev_priv(dev);
 367
 368         free_percpu(br->stats);
 369         free_netdev(dev);
 370 }
 371
 372 static struct device_type br_type = {
 373         .name   = "bridge",
 374 };
 375
 376 void br_dev_setup(struct net_device *dev)
 377 {
 378         struct net_bridge *br = netdev_priv(dev);
 379
 380         random_ether_addr(dev->dev_addr);
 381         ether_setup(dev);
 382
 383         dev->netdev_ops = &br_netdev_ops;
 384         dev->destructor = br_dev_free;
 385         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 386         SET_NETDEV_DEVTYPE(dev, &br_type);
 387         dev->tx_queue_len = 0;
 388         dev->priv_flags = IFF_EBRIDGE;
 389
 390         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 391                         NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX |
 392                         NETIF_F_NETNS_LOCAL | NETIF_F_GSO | NETIF_F_HW_VLAN_TX;
 393
 394         br->dev = dev;
 395         spin_lock_init(&br->lock);
 396         INIT_LIST_HEAD(&br->port_list);
 397         spin_lock_init(&br->hash_lock);
 398
 399         br->bridge_id.prio[0] = 0x80;
 400         br->bridge_id.prio[1] = 0x00;
 401
 402         memcpy(br->group_addr, br_group_address, ETH_ALEN);
 403
 404         br->feature_mask = dev->features;
 405         br->stp_enabled = BR_NO_STP;
 406         br->designated_root = br->bridge_id;
 407         br->bridge_max_age = br->max_age = 20 * HZ;
 408         br->bridge_hello_time = br->hello_time = 2 * HZ;
 409         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 410         br->ageing_time = 300 * HZ;
 411
 412         br_netfilter_rtable_init(br);
 413         br_stp_timer_init(br);
 414         br_multicast_init(br);
 415 }