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         netdev_update_features(dev);
  94         netif_start_queue(dev);
  95         br_stp_enable_bridge(br);
  96         br_multicast_open(br);
  97
  98         return 0;
  99 }
 100
 101 static void br_dev_set_multicast_list(struct net_device *dev)
 102 {
 103 }
 104
 105 static int br_dev_stop(struct net_device *dev)
 106 {
 107         struct net_bridge *br = netdev_priv(dev);
 108
 109         netif_carrier_off(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(&bstats->syncp);
 132                         memcpy(&tmp, bstats, sizeof(tmp));
 133                 } while (u64_stats_fetch_retry(&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 -EINVAL;
 172
 173         spin_lock_bh(&br->lock);
 174         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 175         br_stp_change_bridge_id(br, addr->sa_data);
 176         br->flags |= BR_SET_MAC_ADDR;
 177         spin_unlock_bh(&br->lock);
 178
 179         return 0;
 180 }
 181
 182 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 183 {
 184         strcpy(info->driver, "bridge");
 185         strcpy(info->version, BR_VERSION);
 186         strcpy(info->fw_version, "N/A");
 187         strcpy(info->bus_info, "N/A");
 188 }
 189
 190 static u32 br_fix_features(struct net_device *dev, u32 features)
 191 {
 192         struct net_bridge *br = netdev_priv(dev);
 193
 194         return br_features_recompute(br, features);
 195 }
 196
 197 #ifdef CONFIG_NET_POLL_CONTROLLER
 198 static void br_poll_controller(struct net_device *br_dev)
 199 {
 200 }
 201
 202 static void br_netpoll_cleanup(struct net_device *dev)
 203 {
 204         struct net_bridge *br = netdev_priv(dev);
 205         struct net_bridge_port *p, *n;
 206
 207         list_for_each_entry_safe(p, n, &br->port_list, list) {
 208                 br_netpoll_disable(p);
 209         }
 210 }
 211
 212 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 213 {
 214         struct net_bridge *br = netdev_priv(dev);
 215         struct net_bridge_port *p, *n;
 216         int err = 0;
 217
 218         list_for_each_entry_safe(p, n, &br->port_list, list) {
 219                 if (!p->dev)
 220                         continue;
 221
 222                 err = br_netpoll_enable(p);
 223                 if (err)
 224                         goto fail;
 225         }
 226
 227 out:
 228         return err;
 229
 230 fail:
 231         br_netpoll_cleanup(dev);
 232         goto out;
 233 }
 234
 235 int br_netpoll_enable(struct net_bridge_port *p)
 236 {
 237         struct netpoll *np;
 238         int err = 0;
 239
 240         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 241         err = -ENOMEM;
 242         if (!np)
 243                 goto out;
 244
 245         np->dev = p->dev;
 246         strlcpy(np->dev_name, p->dev->name, IFNAMSIZ);
 247
 248         err = __netpoll_setup(np);
 249         if (err) {
 250                 kfree(np);
 251                 goto out;
 252         }
 253
 254         p->np = np;
 255
 256 out:
 257         return err;
 258 }
 259
 260 void br_netpoll_disable(struct net_bridge_port *p)
 261 {
 262         struct netpoll *np = p->np;
 263
 264         if (!np)
 265                 return;
 266
 267         p->np = NULL;
 268
 269         /* Wait for transmitting packets to finish before freeing. */
 270         synchronize_rcu_bh();
 271
 272         __netpoll_cleanup(np);
 273         kfree(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_multicast_list  = 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 };
 317
 318 static void br_dev_free(struct net_device *dev)
 319 {
 320         struct net_bridge *br = netdev_priv(dev);
 321
 322         free_percpu(br->stats);
 323         free_netdev(dev);
 324 }
 325
 326 static struct device_type br_type = {
 327         .name   = "bridge",
 328 };
 329
 330 void br_dev_setup(struct net_device *dev)
 331 {
 332         struct net_bridge *br = netdev_priv(dev);
 333
 334         random_ether_addr(dev->dev_addr);
 335         ether_setup(dev);
 336
 337         dev->netdev_ops = &br_netdev_ops;
 338         dev->destructor = br_dev_free;
 339         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 340         SET_NETDEV_DEVTYPE(dev, &br_type);
 341         dev->tx_queue_len = 0;
 342         dev->priv_flags = IFF_EBRIDGE;
 343
 344         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 345                         NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX |
 346                         NETIF_F_NETNS_LOCAL | NETIF_F_HW_VLAN_TX;
 347         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 348                            NETIF_F_GSO_MASK | NETIF_F_NO_CSUM |
 349                            NETIF_F_HW_VLAN_TX;
 350
 351         br->dev = dev;
 352         spin_lock_init(&br->lock);
 353         INIT_LIST_HEAD(&br->port_list);
 354         spin_lock_init(&br->hash_lock);
 355
 356         br->bridge_id.prio[0] = 0x80;
 357         br->bridge_id.prio[1] = 0x00;
 358
 359         memcpy(br->group_addr, br_group_address, ETH_ALEN);
 360
 361         br->stp_enabled = BR_NO_STP;
 362         br->designated_root = br->bridge_id;
 363         br->bridge_max_age = br->max_age = 20 * HZ;
 364         br->bridge_hello_time = br->hello_time = 2 * HZ;
 365         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 366         br->ageing_time = 300 * HZ;
 367
 368         br_netfilter_rtable_init(br);
 369         br_stp_timer_init(br);
 370         br_multicast_init(br);
 371 }