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         netdev_update_features(dev);
  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         br_stp_disable_bridge(br);
 111         br_multicast_stop(br);
 112
 113         netif_stop_queue(dev);
 114
 115         return 0;
 116 }
 117
 118 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 119                                                 struct rtnl_link_stats64 *stats)
 120 {
 121         struct net_bridge *br = netdev_priv(dev);
 122         struct br_cpu_netstats tmp, sum = { 0 };
 123         unsigned int cpu;
 124
 125         for_each_possible_cpu(cpu) {
 126                 unsigned int start;
 127                 const struct br_cpu_netstats *bstats
 128                         = per_cpu_ptr(br->stats, cpu);
 129                 do {
 130                         start = u64_stats_fetch_begin(&bstats->syncp);
 131                         memcpy(&tmp, bstats, sizeof(tmp));
 132                 } while (u64_stats_fetch_retry(&bstats->syncp, start));
 133                 sum.tx_bytes   += tmp.tx_bytes;
 134                 sum.tx_packets += tmp.tx_packets;
 135                 sum.rx_bytes   += tmp.rx_bytes;
 136                 sum.rx_packets += tmp.rx_packets;
 137         }
 138
 139         stats->tx_bytes   = sum.tx_bytes;
 140         stats->tx_packets = sum.tx_packets;
 141         stats->rx_bytes   = sum.rx_bytes;
 142         stats->rx_packets = sum.rx_packets;
 143
 144         return stats;
 145 }
 146
 147 static int br_change_mtu(struct net_device *dev, int new_mtu)
 148 {
 149         struct net_bridge *br = netdev_priv(dev);
 150         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 151                 return -EINVAL;
 152
 153         dev->mtu = new_mtu;
 154
 155 #ifdef CONFIG_BRIDGE_NETFILTER
 156         /* remember the MTU in the rtable for PMTU */
 157         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 158 #endif
 159
 160         return 0;
 161 }
 162
 163 /* Allow setting mac address to any valid ethernet address. */
 164 static int br_set_mac_address(struct net_device *dev, void *p)
 165 {
 166         struct net_bridge *br = netdev_priv(dev);
 167         struct sockaddr *addr = p;
 168
 169         if (!is_valid_ether_addr(addr->sa_data))
 170                 return -EINVAL;
 171
 172         spin_lock_bh(&br->lock);
 173         memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 174         br_stp_change_bridge_id(br, addr->sa_data);
 175         br->flags |= BR_SET_MAC_ADDR;
 176         spin_unlock_bh(&br->lock);
 177
 178         return 0;
 179 }
 180
 181 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 182 {
 183         strcpy(info->driver, "bridge");
 184         strcpy(info->version, BR_VERSION);
 185         strcpy(info->fw_version, "N/A");
 186         strcpy(info->bus_info, "N/A");
 187 }
 188
 189 static u32 br_fix_features(struct net_device *dev, u32 features)
 190 {
 191         struct net_bridge *br = netdev_priv(dev);
 192
 193         return br_features_recompute(br, features);
 194 }
 195
 196 #ifdef CONFIG_NET_POLL_CONTROLLER
 197 static void br_poll_controller(struct net_device *br_dev)
 198 {
 199 }
 200
 201 static void br_netpoll_cleanup(struct net_device *dev)
 202 {
 203         struct net_bridge *br = netdev_priv(dev);
 204         struct net_bridge_port *p, *n;
 205
 206         list_for_each_entry_safe(p, n, &br->port_list, list) {
 207                 br_netpoll_disable(p);
 208         }
 209 }
 210
 211 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 212 {
 213         struct net_bridge *br = netdev_priv(dev);
 214         struct net_bridge_port *p, *n;
 215         int err = 0;
 216
 217         list_for_each_entry_safe(p, n, &br->port_list, list) {
 218                 if (!p->dev)
 219                         continue;
 220
 221                 err = br_netpoll_enable(p);
 222                 if (err)
 223                         goto fail;
 224         }
 225
 226 out:
 227         return err;
 228
 229 fail:
 230         br_netpoll_cleanup(dev);
 231         goto out;
 232 }
 233
 234 int br_netpoll_enable(struct net_bridge_port *p)
 235 {
 236         struct netpoll *np;
 237         int err = 0;
 238
 239         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 240         err = -ENOMEM;
 241         if (!np)
 242                 goto out;
 243
 244         np->dev = p->dev;
 245         strlcpy(np->dev_name, p->dev->name, IFNAMSIZ);
 246
 247         err = __netpoll_setup(np);
 248         if (err) {
 249                 kfree(np);
 250                 goto out;
 251         }
 252
 253         p->np = np;
 254
 255 out:
 256         return err;
 257 }
 258
 259 void br_netpoll_disable(struct net_bridge_port *p)
 260 {
 261         struct netpoll *np = p->np;
 262
 263         if (!np)
 264                 return;
 265
 266         p->np = NULL;
 267
 268         /* Wait for transmitting packets to finish before freeing. */
 269         synchronize_rcu_bh();
 270
 271         __netpoll_cleanup(np);
 272         kfree(np);
 273 }
 274
 275 #endif
 276
 277 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 278
 279 {
 280         struct net_bridge *br = netdev_priv(dev);
 281
 282         return br_add_if(br, slave_dev);
 283 }
 284
 285 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 286 {
 287         struct net_bridge *br = netdev_priv(dev);
 288
 289         return br_del_if(br, slave_dev);
 290 }
 291
 292 static const struct ethtool_ops br_ethtool_ops = {
 293         .get_drvinfo    = br_getinfo,
 294         .get_link       = ethtool_op_get_link,
 295 };
 296
 297 static const struct net_device_ops br_netdev_ops = {
 298         .ndo_open                = br_dev_open,
 299         .ndo_stop                = br_dev_stop,
 300         .ndo_init                = br_dev_init,
 301         .ndo_start_xmit          = br_dev_xmit,
 302         .ndo_get_stats64         = br_get_stats64,
 303         .ndo_set_mac_address     = br_set_mac_address,
 304         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 305         .ndo_change_mtu          = br_change_mtu,
 306         .ndo_do_ioctl            = br_dev_ioctl,
 307 #ifdef CONFIG_NET_POLL_CONTROLLER
 308         .ndo_netpoll_setup       = br_netpoll_setup,
 309         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 310         .ndo_poll_controller     = br_poll_controller,
 311 #endif
 312         .ndo_add_slave           = br_add_slave,
 313         .ndo_del_slave           = br_del_slave,
 314         .ndo_fix_features        = br_fix_features,
 315 };
 316
 317 static void br_dev_free(struct net_device *dev)
 318 {
 319         struct net_bridge *br = netdev_priv(dev);
 320
 321         free_percpu(br->stats);
 322         free_netdev(dev);
 323 }
 324
 325 static struct device_type br_type = {
 326         .name   = "bridge",
 327 };
 328
 329 void br_dev_setup(struct net_device *dev)
 330 {
 331         struct net_bridge *br = netdev_priv(dev);
 332
 333         random_ether_addr(dev->dev_addr);
 334         ether_setup(dev);
 335
 336         dev->netdev_ops = &br_netdev_ops;
 337         dev->destructor = br_dev_free;
 338         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 339         SET_NETDEV_DEVTYPE(dev, &br_type);
 340         dev->tx_queue_len = 0;
 341         dev->priv_flags = IFF_EBRIDGE;
 342
 343         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 344                         NETIF_F_GSO_MASK | NETIF_F_NO_CSUM | NETIF_F_LLTX |
 345                         NETIF_F_NETNS_LOCAL | NETIF_F_HW_VLAN_TX;
 346         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 347                            NETIF_F_GSO_MASK | NETIF_F_NO_CSUM |
 348                            NETIF_F_HW_VLAN_TX;
 349
 350         br->dev = dev;
 351         spin_lock_init(&br->lock);
 352         INIT_LIST_HEAD(&br->port_list);
 353         spin_lock_init(&br->hash_lock);
 354
 355         br->bridge_id.prio[0] = 0x80;
 356         br->bridge_id.prio[1] = 0x00;
 357
 358         memcpy(br->group_addr, br_group_address, ETH_ALEN);
 359
 360         br->stp_enabled = BR_NO_STP;
 361         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 362
 363         br->designated_root = br->bridge_id;
 364         br->bridge_max_age = br->max_age = 20 * HZ;
 365         br->bridge_hello_time = br->hello_time = 2 * HZ;
 366         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 367         br->ageing_time = 300 * HZ;
 368
 369         br_netfilter_rtable_init(br);
 370         br_stp_timer_init(br);
 371         br_multicast_init(br);
 372 }