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         u16 vid = 0;
  34
  35         rcu_read_lock();
  36 #ifdef CONFIG_BRIDGE_NETFILTER
  37         if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
  38                 br_nf_pre_routing_finish_bridge_slow(skb);
  39                 rcu_read_unlock();
  40                 return NETDEV_TX_OK;
  41         }
  42 #endif
  43
  44         if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid))
  45                 goto out;
  46
  47         BR_INPUT_SKB_CB(skb)->brdev = dev;
  48
  49         skb_reset_mac_header(skb);
  50         skb_pull(skb, ETH_HLEN);
  51
  52         u64_stats_update_begin(&brstats->syncp);
  53         brstats->tx_packets++;
  54         /* Exclude ETH_HLEN from byte stats for consistency with Rx chain */
  55         brstats->tx_bytes += skb->len;
  56         u64_stats_update_end(&brstats->syncp);
  57
  58         if (is_broadcast_ether_addr(dest))
  59                 br_flood_deliver(br, skb);
  60         else if (is_multicast_ether_addr(dest)) {
  61                 if (unlikely(netpoll_tx_running(dev))) {
  62                         br_flood_deliver(br, skb);
  63                         goto out;
  64                 }
  65                 if (br_multicast_rcv(br, NULL, skb)) {
  66                         kfree_skb(skb);
  67                         goto out;
  68                 }
  69
  70                 mdst = br_mdb_get(br, skb, vid);
  71                 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb))
  72                         br_multicast_deliver(mdst, skb);
  73                 else
  74                         br_flood_deliver(br, skb);
  75         } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL)
  76                 br_deliver(dst->dst, skb);
  77         else
  78                 br_flood_deliver(br, skb);
  79
  80 out:
  81         rcu_read_unlock();
  82         return NETDEV_TX_OK;
  83 }
  84
  85 static int br_dev_init(struct net_device *dev)
  86 {
  87         struct net_bridge *br = netdev_priv(dev);
  88
  89         br->stats = alloc_percpu(struct br_cpu_netstats);
  90         if (!br->stats)
  91                 return -ENOMEM;
  92
  93         return 0;
  94 }
  95
  96 static int br_dev_open(struct net_device *dev)
  97 {
  98         struct net_bridge *br = netdev_priv(dev);
  99
 100         netdev_update_features(dev);
 101         netif_start_queue(dev);
 102         br_stp_enable_bridge(br);
 103         br_multicast_open(br);
 104
 105         return 0;
 106 }
 107
 108 static void br_dev_set_multicast_list(struct net_device *dev)
 109 {
 110 }
 111
 112 static int br_dev_stop(struct net_device *dev)
 113 {
 114         struct net_bridge *br = netdev_priv(dev);
 115
 116         br_stp_disable_bridge(br);
 117         br_multicast_stop(br);
 118
 119         netif_stop_queue(dev);
 120
 121         return 0;
 122 }
 123
 124 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 125                                                 struct rtnl_link_stats64 *stats)
 126 {
 127         struct net_bridge *br = netdev_priv(dev);
 128         struct br_cpu_netstats tmp, sum = { 0 };
 129         unsigned int cpu;
 130
 131         for_each_possible_cpu(cpu) {
 132                 unsigned int start;
 133                 const struct br_cpu_netstats *bstats
 134                         = per_cpu_ptr(br->stats, cpu);
 135                 do {
 136                         start = u64_stats_fetch_begin_bh(&bstats->syncp);
 137                         memcpy(&tmp, bstats, sizeof(tmp));
 138                 } while (u64_stats_fetch_retry_bh(&bstats->syncp, start));
 139                 sum.tx_bytes   += tmp.tx_bytes;
 140                 sum.tx_packets += tmp.tx_packets;
 141                 sum.rx_bytes   += tmp.rx_bytes;
 142                 sum.rx_packets += tmp.rx_packets;
 143         }
 144
 145         stats->tx_bytes   = sum.tx_bytes;
 146         stats->tx_packets = sum.tx_packets;
 147         stats->rx_bytes   = sum.rx_bytes;
 148         stats->rx_packets = sum.rx_packets;
 149
 150         return stats;
 151 }
 152
 153 static int br_change_mtu(struct net_device *dev, int new_mtu)
 154 {
 155         struct net_bridge *br = netdev_priv(dev);
 156         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 157                 return -EINVAL;
 158
 159         dev->mtu = new_mtu;
 160
 161 #ifdef CONFIG_BRIDGE_NETFILTER
 162         /* remember the MTU in the rtable for PMTU */
 163         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 164 #endif
 165
 166         return 0;
 167 }
 168
 169 /* Allow setting mac address to any valid ethernet address. */
 170 static int br_set_mac_address(struct net_device *dev, void *p)
 171 {
 172         struct net_bridge *br = netdev_priv(dev);
 173         struct sockaddr *addr = p;
 174
 175         if (!is_valid_ether_addr(addr->sa_data))
 176                 return -EADDRNOTAVAIL;
 177
 178         spin_lock_bh(&br->lock);
 179         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 180                 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 181                 br_fdb_change_mac_address(br, addr->sa_data);
 182                 br_stp_change_bridge_id(br, addr->sa_data);
 183         }
 184         spin_unlock_bh(&br->lock);
 185
 186         return 0;
 187 }
 188
 189 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 190 {
 191         strlcpy(info->driver, "bridge", sizeof(info->driver));
 192         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 193         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 194         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 195 }
 196
 197 static netdev_features_t br_fix_features(struct net_device *dev,
 198         netdev_features_t features)
 199 {
 200         struct net_bridge *br = netdev_priv(dev);
 201
 202         return br_features_recompute(br, features);
 203 }
 204
 205 #ifdef CONFIG_NET_POLL_CONTROLLER
 206 static void br_poll_controller(struct net_device *br_dev)
 207 {
 208 }
 209
 210 static void br_netpoll_cleanup(struct net_device *dev)
 211 {
 212         struct net_bridge *br = netdev_priv(dev);
 213         struct net_bridge_port *p;
 214
 215         list_for_each_entry(p, &br->port_list, list)
 216                 br_netpoll_disable(p);
 217 }
 218
 219 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni,
 220                             gfp_t gfp)
 221 {
 222         struct net_bridge *br = netdev_priv(dev);
 223         struct net_bridge_port *p;
 224         int err = 0;
 225
 226         list_for_each_entry(p, &br->port_list, list) {
 227                 if (!p->dev)
 228                         continue;
 229                 err = br_netpoll_enable(p, gfp);
 230                 if (err)
 231                         goto fail;
 232         }
 233
 234 out:
 235         return err;
 236
 237 fail:
 238         br_netpoll_cleanup(dev);
 239         goto out;
 240 }
 241
 242 int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp)
 243 {
 244         struct netpoll *np;
 245         int err = 0;
 246
 247         np = kzalloc(sizeof(*p->np), gfp);
 248         err = -ENOMEM;
 249         if (!np)
 250                 goto out;
 251
 252         err = __netpoll_setup(np, p->dev, gfp);
 253         if (err) {
 254                 kfree(np);
 255                 goto out;
 256         }
 257
 258         p->np = np;
 259
 260 out:
 261         return err;
 262 }
 263
 264 void br_netpoll_disable(struct net_bridge_port *p)
 265 {
 266         struct netpoll *np = p->np;
 267
 268         if (!np)
 269                 return;
 270
 271         p->np = NULL;
 272
 273         __netpoll_free_async(np);
 274 }
 275
 276 #endif
 277
 278 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 279
 280 {
 281         struct net_bridge *br = netdev_priv(dev);
 282
 283         return br_add_if(br, slave_dev);
 284 }
 285
 286 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 287 {
 288         struct net_bridge *br = netdev_priv(dev);
 289
 290         return br_del_if(br, slave_dev);
 291 }
 292
 293 static const struct ethtool_ops br_ethtool_ops = {
 294         .get_drvinfo    = br_getinfo,
 295         .get_link       = ethtool_op_get_link,
 296 };
 297
 298 static const struct net_device_ops br_netdev_ops = {
 299         .ndo_open                = br_dev_open,
 300         .ndo_stop                = br_dev_stop,
 301         .ndo_init                = br_dev_init,
 302         .ndo_start_xmit          = br_dev_xmit,
 303         .ndo_get_stats64         = br_get_stats64,
 304         .ndo_set_mac_address     = br_set_mac_address,
 305         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 306         .ndo_change_mtu          = br_change_mtu,
 307         .ndo_do_ioctl            = br_dev_ioctl,
 308 #ifdef CONFIG_NET_POLL_CONTROLLER
 309         .ndo_netpoll_setup       = br_netpoll_setup,
 310         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 311         .ndo_poll_controller     = br_poll_controller,
 312 #endif
 313         .ndo_add_slave           = br_add_slave,
 314         .ndo_del_slave           = br_del_slave,
 315         .ndo_fix_features        = br_fix_features,
 316         .ndo_fdb_add             = br_fdb_add,
 317         .ndo_fdb_del             = br_fdb_delete,
 318         .ndo_fdb_dump            = br_fdb_dump,
 319         .ndo_bridge_getlink      = br_getlink,
 320         .ndo_bridge_setlink      = br_setlink,
 321         .ndo_bridge_dellink      = br_dellink,
 322 };
 323
 324 static void br_dev_free(struct net_device *dev)
 325 {
 326         struct net_bridge *br = netdev_priv(dev);
 327
 328         free_percpu(br->stats);
 329         free_netdev(dev);
 330 }
 331
 332 static struct device_type br_type = {
 333         .name   = "bridge",
 334 };
 335
 336 void br_dev_setup(struct net_device *dev)
 337 {
 338         struct net_bridge *br = netdev_priv(dev);
 339
 340         eth_hw_addr_random(dev);
 341         ether_setup(dev);
 342
 343         dev->netdev_ops = &br_netdev_ops;
 344         dev->destructor = br_dev_free;
 345         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 346         SET_NETDEV_DEVTYPE(dev, &br_type);
 347         dev->tx_queue_len = 0;
 348         dev->priv_flags = IFF_EBRIDGE;
 349
 350         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 351                         NETIF_F_GSO_MASK | NETIF_F_HW_CSUM | NETIF_F_LLTX |
 352                         NETIF_F_NETNS_LOCAL | NETIF_F_HW_VLAN_CTAG_TX;
 353         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 354                            NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
 355                            NETIF_F_HW_VLAN_CTAG_TX;
 356
 357         br->dev = dev;
 358         spin_lock_init(&br->lock);
 359         INIT_LIST_HEAD(&br->port_list);
 360         spin_lock_init(&br->hash_lock);
 361
 362         br->bridge_id.prio[0] = 0x80;
 363         br->bridge_id.prio[1] = 0x00;
 364
 365         memcpy(br->group_addr, eth_reserved_addr_base, ETH_ALEN);
 366
 367         br->stp_enabled = BR_NO_STP;
 368         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 369
 370         br->designated_root = br->bridge_id;
 371         br->bridge_max_age = br->max_age = 20 * HZ;
 372         br->bridge_hello_time = br->hello_time = 2 * HZ;
 373         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 374         br->ageing_time = 300 * HZ;
 375
 376         br_netfilter_rtable_init(br);
 377         br_stp_timer_init(br);
 378         br_multicast_init(br);
 379 }