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_broadcast_ether_addr(dest))
  53                 br_flood_deliver(br, skb);
  54         else if (is_multicast_ether_addr(dest)) {
  55                 if (unlikely(netpoll_tx_running(dev))) {
  56                         br_flood_deliver(br, skb);
  57                         goto out;
  58                 }
  59                 if (br_multicast_rcv(br, NULL, skb)) {
  60                         kfree_skb(skb);
  61                         goto out;
  62                 }
  63
  64                 mdst = br_mdb_get(br, skb);
  65                 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb))
  66                         br_multicast_deliver(mdst, skb);
  67                 else
  68                         br_flood_deliver(br, skb);
  69         } else if ((dst = __br_fdb_get(br, dest)) != NULL)
  70                 br_deliver(dst->dst, skb);
  71         else
  72                 br_flood_deliver(br, skb);
  73
  74 out:
  75         rcu_read_unlock();
  76         return NETDEV_TX_OK;
  77 }
  78
  79 static int br_dev_init(struct net_device *dev)
  80 {
  81         struct net_bridge *br = netdev_priv(dev);
  82
  83         br->stats = alloc_percpu(struct br_cpu_netstats);
  84         if (!br->stats)
  85                 return -ENOMEM;
  86
  87         return 0;
  88 }
  89
  90 static int br_dev_open(struct net_device *dev)
  91 {
  92         struct net_bridge *br = netdev_priv(dev);
  93
  94         netif_carrier_off(dev);
  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         netif_carrier_off(dev);
 112
 113         br_stp_disable_bridge(br);
 114         br_multicast_stop(br);
 115
 116         netif_stop_queue(dev);
 117
 118         return 0;
 119 }
 120
 121 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 122                                                 struct rtnl_link_stats64 *stats)
 123 {
 124         struct net_bridge *br = netdev_priv(dev);
 125         struct br_cpu_netstats tmp, sum = { 0 };
 126         unsigned int cpu;
 127
 128         for_each_possible_cpu(cpu) {
 129                 unsigned int start;
 130                 const struct br_cpu_netstats *bstats
 131                         = per_cpu_ptr(br->stats, cpu);
 132                 do {
 133                         start = u64_stats_fetch_begin(&bstats->syncp);
 134                         memcpy(&tmp, bstats, sizeof(tmp));
 135                 } while (u64_stats_fetch_retry(&bstats->syncp, start));
 136                 sum.tx_bytes   += tmp.tx_bytes;
 137                 sum.tx_packets += tmp.tx_packets;
 138                 sum.rx_bytes   += tmp.rx_bytes;
 139                 sum.rx_packets += tmp.rx_packets;
 140         }
 141
 142         stats->tx_bytes   = sum.tx_bytes;
 143         stats->tx_packets = sum.tx_packets;
 144         stats->rx_bytes   = sum.rx_bytes;
 145         stats->rx_packets = sum.rx_packets;
 146
 147         return stats;
 148 }
 149
 150 static int br_change_mtu(struct net_device *dev, int new_mtu)
 151 {
 152         struct net_bridge *br = netdev_priv(dev);
 153         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 154                 return -EINVAL;
 155
 156         dev->mtu = new_mtu;
 157
 158 #ifdef CONFIG_BRIDGE_NETFILTER
 159         /* remember the MTU in the rtable for PMTU */
 160         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 161 #endif
 162
 163         return 0;
 164 }
 165
 166 /* Allow setting mac address to any valid ethernet address. */
 167 static int br_set_mac_address(struct net_device *dev, void *p)
 168 {
 169         struct net_bridge *br = netdev_priv(dev);
 170         struct sockaddr *addr = p;
 171
 172         if (!is_valid_ether_addr(addr->sa_data))
 173                 return -EINVAL;
 174
 175         spin_lock_bh(&br->lock);
 176         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 177         br_stp_change_bridge_id(br, addr->sa_data);
 178         br->flags |= BR_SET_MAC_ADDR;
 179         spin_unlock_bh(&br->lock);
 180
 181         return 0;
 182 }
 183
 184 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 185 {
 186         strcpy(info->driver, "bridge");
 187         strcpy(info->version, BR_VERSION);
 188         strcpy(info->fw_version, "N/A");
 189         strcpy(info->bus_info, "N/A");
 190 }
 191
 192 static u32 br_fix_features(struct net_device *dev, u32 features)
 193 {
 194         struct net_bridge *br = netdev_priv(dev);
 195
 196         return br_features_recompute(br, features);
 197 }
 198
 199 #ifdef CONFIG_NET_POLL_CONTROLLER
 200 static void br_poll_controller(struct net_device *br_dev)
 201 {
 202 }
 203
 204 static void br_netpoll_cleanup(struct net_device *dev)
 205 {
 206         struct net_bridge *br = netdev_priv(dev);
 207         struct net_bridge_port *p, *n;
 208
 209         list_for_each_entry_safe(p, n, &br->port_list, list) {
 210                 br_netpoll_disable(p);
 211         }
 212 }
 213
 214 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 215 {
 216         struct net_bridge *br = netdev_priv(dev);
 217         struct net_bridge_port *p, *n;
 218         int err = 0;
 219
 220         list_for_each_entry_safe(p, n, &br->port_list, list) {
 221                 if (!p->dev)
 222                         continue;
 223
 224                 err = br_netpoll_enable(p);
 225                 if (err)
 226                         goto fail;
 227         }
 228
 229 out:
 230         return err;
 231
 232 fail:
 233         br_netpoll_cleanup(dev);
 234         goto out;
 235 }
 236
 237 int br_netpoll_enable(struct net_bridge_port *p)
 238 {
 239         struct netpoll *np;
 240         int err = 0;
 241
 242         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 243         err = -ENOMEM;
 244         if (!np)
 245                 goto out;
 246
 247         np->dev = p->dev;
 248         strlcpy(np->dev_name, p->dev->name, IFNAMSIZ);
 249
 250         err = __netpoll_setup(np);
 251         if (err) {
 252                 kfree(np);
 253                 goto out;
 254         }
 255
 256         p->np = np;
 257
 258 out:
 259         return err;
 260 }
 261
 262 void br_netpoll_disable(struct net_bridge_port *p)
 263 {
 264         struct netpoll *np = p->np;
 265
 266         if (!np)
 267                 return;
 268
 269         p->np = NULL;
 270
 271         /* Wait for transmitting packets to finish before freeing. */
 272         synchronize_rcu_bh();
 273
 274         __netpoll_cleanup(np);
 275         kfree(np);
 276 }
 277
 278 #endif
 279
 280 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 281
 282 {
 283         struct net_bridge *br = netdev_priv(dev);
 284
 285         return br_add_if(br, slave_dev);
 286 }
 287
 288 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 289 {
 290         struct net_bridge *br = netdev_priv(dev);
 291
 292         return br_del_if(br, slave_dev);
 293 }
 294
 295 static const struct ethtool_ops br_ethtool_ops = {
 296         .get_drvinfo    = br_getinfo,
 297         .get_link       = ethtool_op_get_link,
 298 };
 299
 300 static const struct net_device_ops br_netdev_ops = {
 301         .ndo_open                = br_dev_open,
 302         .ndo_stop                = br_dev_stop,
 303         .ndo_init                = br_dev_init,
 304         .ndo_start_xmit          = br_dev_xmit,
 305         .ndo_get_stats64         = br_get_stats64,
 306         .ndo_set_mac_address     = br_set_mac_address,
 307         .ndo_set_multicast_list  = br_dev_set_multicast_list,
 308         .ndo_change_mtu          = br_change_mtu,
 309         .ndo_do_ioctl            = br_dev_ioctl,
 310 #ifdef CONFIG_NET_POLL_CONTROLLER
 311         .ndo_netpoll_setup       = br_netpoll_setup,
 312         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 313         .ndo_poll_controller     = br_poll_controller,
 314 #endif
 315         .ndo_add_slave           = br_add_slave,
 316         .ndo_del_slave           = br_del_slave,
 317         .ndo_fix_features        = br_fix_features,
 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         random_ether_addr(dev->dev_addr);
 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_NO_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_NO_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, br_group_address, ETH_ALEN);
 362
 363         br->stp_enabled = BR_NO_STP;
 364         br->designated_root = br->bridge_id;
 365         br->bridge_max_age = br->max_age = 20 * HZ;
 366         br->bridge_hello_time = br->hello_time = 2 * HZ;
 367         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 368         br->ageing_time = 300 * HZ;
 369
 370         br_netfilter_rtable_init(br);
 371         br_stp_timer_init(br);
 372         br_multicast_init(br);
 373 }