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