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 #define COMMON_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA | \
  26                          NETIF_F_GSO_MASK | NETIF_F_HW_CSUM)
  27
  28 /* net device transmit always called with BH disabled */
  29 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
  30 {
  31         struct net_bridge *br = netdev_priv(dev);
  32         const unsigned char *dest = skb->data;
  33         struct net_bridge_fdb_entry *dst;
  34         struct net_bridge_mdb_entry *mdst;
  35         struct br_cpu_netstats *brstats = this_cpu_ptr(br->stats);
  36         u16 vid = 0;
  37
  38         rcu_read_lock();
  39 #ifdef CONFIG_BRIDGE_NETFILTER
  40         if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
  41                 br_nf_pre_routing_finish_bridge_slow(skb);
  42                 rcu_read_unlock();
  43                 return NETDEV_TX_OK;
  44         }
  45 #endif
  46
  47         u64_stats_update_begin(&brstats->syncp);
  48         brstats->tx_packets++;
  49         brstats->tx_bytes += skb->len;
  50         u64_stats_update_end(&brstats->syncp);
  51
  52         if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid))
  53                 goto out;
  54
  55         BR_INPUT_SKB_CB(skb)->brdev = dev;
  56
  57         skb_reset_mac_header(skb);
  58         skb_pull(skb, ETH_HLEN);
  59
  60         if (is_broadcast_ether_addr(dest))
  61                 br_flood_deliver(br, skb, false);
  62         else if (is_multicast_ether_addr(dest)) {
  63                 if (unlikely(netpoll_tx_running(dev))) {
  64                         br_flood_deliver(br, skb, false);
  65                         goto out;
  66                 }
  67                 if (br_multicast_rcv(br, NULL, skb)) {
  68                         kfree_skb(skb);
  69                         goto out;
  70                 }
  71
  72                 mdst = br_mdb_get(br, skb, vid);
  73                 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb))
  74                         br_multicast_deliver(mdst, skb);
  75                 else
  76                         br_flood_deliver(br, skb, false);
  77         } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL)
  78                 br_deliver(dst->dst, skb);
  79         else
  80                 br_flood_deliver(br, skb, true);
  81
  82 out:
  83         rcu_read_unlock();
  84         return NETDEV_TX_OK;
  85 }
  86
  87 static int br_dev_init(struct net_device *dev)
  88 {
  89         struct net_bridge *br = netdev_priv(dev);
  90
  91         br->stats = alloc_percpu(struct br_cpu_netstats);
  92         if (!br->stats)
  93                 return -ENOMEM;
  94
  95         return 0;
  96 }
  97
  98 static int br_dev_open(struct net_device *dev)
  99 {
 100         struct net_bridge *br = netdev_priv(dev);
 101
 102         netdev_update_features(dev);
 103         netif_start_queue(dev);
 104         br_stp_enable_bridge(br);
 105         br_multicast_open(br);
 106
 107         return 0;
 108 }
 109
 110 static void br_dev_set_multicast_list(struct net_device *dev)
 111 {
 112 }
 113
 114 static int br_dev_stop(struct net_device *dev)
 115 {
 116         struct net_bridge *br = netdev_priv(dev);
 117
 118         br_stp_disable_bridge(br);
 119         br_multicast_stop(br);
 120
 121         netif_stop_queue(dev);
 122
 123         return 0;
 124 }
 125
 126 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 127                                                 struct rtnl_link_stats64 *stats)
 128 {
 129         struct net_bridge *br = netdev_priv(dev);
 130         struct br_cpu_netstats tmp, sum = { 0 };
 131         unsigned int cpu;
 132
 133         for_each_possible_cpu(cpu) {
 134                 unsigned int start;
 135                 const struct br_cpu_netstats *bstats
 136                         = per_cpu_ptr(br->stats, cpu);
 137                 do {
 138                         start = u64_stats_fetch_begin_bh(&bstats->syncp);
 139                         memcpy(&tmp, bstats, sizeof(tmp));
 140                 } while (u64_stats_fetch_retry_bh(&bstats->syncp, start));
 141                 sum.tx_bytes   += tmp.tx_bytes;
 142                 sum.tx_packets += tmp.tx_packets;
 143                 sum.rx_bytes   += tmp.rx_bytes;
 144                 sum.rx_packets += tmp.rx_packets;
 145         }
 146
 147         stats->tx_bytes   = sum.tx_bytes;
 148         stats->tx_packets = sum.tx_packets;
 149         stats->rx_bytes   = sum.rx_bytes;
 150         stats->rx_packets = sum.rx_packets;
 151
 152         return stats;
 153 }
 154
 155 static int br_change_mtu(struct net_device *dev, int new_mtu)
 156 {
 157         struct net_bridge *br = netdev_priv(dev);
 158         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 159                 return -EINVAL;
 160
 161         dev->mtu = new_mtu;
 162
 163 #ifdef CONFIG_BRIDGE_NETFILTER
 164         /* remember the MTU in the rtable for PMTU */
 165         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 166 #endif
 167
 168         return 0;
 169 }
 170
 171 /* Allow setting mac address to any valid ethernet address. */
 172 static int br_set_mac_address(struct net_device *dev, void *p)
 173 {
 174         struct net_bridge *br = netdev_priv(dev);
 175         struct sockaddr *addr = p;
 176
 177         if (!is_valid_ether_addr(addr->sa_data))
 178                 return -EADDRNOTAVAIL;
 179
 180         spin_lock_bh(&br->lock);
 181         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 182                 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 183                 br_fdb_change_mac_address(br, addr->sa_data);
 184                 br_stp_change_bridge_id(br, addr->sa_data);
 185         }
 186         spin_unlock_bh(&br->lock);
 187
 188         return 0;
 189 }
 190
 191 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 192 {
 193         strlcpy(info->driver, "bridge", sizeof(info->driver));
 194         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 195         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 196         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 197 }
 198
 199 static netdev_features_t br_fix_features(struct net_device *dev,
 200         netdev_features_t features)
 201 {
 202         struct net_bridge *br = netdev_priv(dev);
 203
 204         return br_features_recompute(br, features);
 205 }
 206
 207 #ifdef CONFIG_NET_POLL_CONTROLLER
 208 static void br_poll_controller(struct net_device *br_dev)
 209 {
 210 }
 211
 212 static void br_netpoll_cleanup(struct net_device *dev)
 213 {
 214         struct net_bridge *br = netdev_priv(dev);
 215         struct net_bridge_port *p;
 216
 217         list_for_each_entry(p, &br->port_list, list)
 218                 br_netpoll_disable(p);
 219 }
 220
 221 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni,
 222                             gfp_t gfp)
 223 {
 224         struct net_bridge *br = netdev_priv(dev);
 225         struct net_bridge_port *p;
 226         int err = 0;
 227
 228         list_for_each_entry(p, &br->port_list, list) {
 229                 if (!p->dev)
 230                         continue;
 231                 err = br_netpoll_enable(p, gfp);
 232                 if (err)
 233                         goto fail;
 234         }
 235
 236 out:
 237         return err;
 238
 239 fail:
 240         br_netpoll_cleanup(dev);
 241         goto out;
 242 }
 243
 244 int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp)
 245 {
 246         struct netpoll *np;
 247         int err = 0;
 248
 249         np = kzalloc(sizeof(*p->np), gfp);
 250         err = -ENOMEM;
 251         if (!np)
 252                 goto out;
 253
 254         err = __netpoll_setup(np, p->dev, gfp);
 255         if (err) {
 256                 kfree(np);
 257                 goto out;
 258         }
 259
 260         p->np = np;
 261
 262 out:
 263         return err;
 264 }
 265
 266 void br_netpoll_disable(struct net_bridge_port *p)
 267 {
 268         struct netpoll *np = p->np;
 269
 270         if (!np)
 271                 return;
 272
 273         p->np = NULL;
 274
 275         __netpoll_free_async(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_rx_mode         = 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         .ndo_fdb_add             = br_fdb_add,
 319         .ndo_fdb_del             = br_fdb_delete,
 320         .ndo_fdb_dump            = br_fdb_dump,
 321         .ndo_bridge_getlink      = br_getlink,
 322         .ndo_bridge_setlink      = br_setlink,
 323         .ndo_bridge_dellink      = br_dellink,
 324 };
 325
 326 static void br_dev_free(struct net_device *dev)
 327 {
 328         struct net_bridge *br = netdev_priv(dev);
 329
 330         free_percpu(br->stats);
 331         free_netdev(dev);
 332 }
 333
 334 static struct device_type br_type = {
 335         .name   = "bridge",
 336 };
 337
 338 void br_dev_setup(struct net_device *dev)
 339 {
 340         struct net_bridge *br = netdev_priv(dev);
 341
 342         eth_hw_addr_random(dev);
 343         ether_setup(dev);
 344
 345         dev->netdev_ops = &br_netdev_ops;
 346         dev->destructor = br_dev_free;
 347         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 348         SET_NETDEV_DEVTYPE(dev, &br_type);
 349         dev->tx_queue_len = 0;
 350         dev->priv_flags = IFF_EBRIDGE;
 351
 352         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 353                         NETIF_F_HW_VLAN_CTAG_TX;
 354         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX;
 355         dev->vlan_features = COMMON_FEATURES;
 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 }