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 pcpu_sw_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         BR_INPUT_SKB_CB(skb)->brdev = dev;
  53
  54         skb_reset_mac_header(skb);
  55         skb_pull(skb, ETH_HLEN);
  56
  57         if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid))
  58                 goto out;
  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, vid)) {
  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_querier_exists(br, eth_hdr(skb)))
  75                         br_multicast_deliver(mdst, skb);
  76                 else
  77                         br_flood_deliver(br, skb, false);
  78         } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL)
  79                 br_deliver(dst->dst, skb);
  80         else
  81                 br_flood_deliver(br, skb, true);
  82
  83 out:
  84         rcu_read_unlock();
  85         return NETDEV_TX_OK;
  86 }
  87
  88 static int br_dev_init(struct net_device *dev)
  89 {
  90         struct net_bridge *br = netdev_priv(dev);
  91         int i;
  92
  93         br->stats = alloc_percpu(struct pcpu_sw_netstats);
  94         if (!br->stats)
  95                 return -ENOMEM;
  96
  97         for_each_possible_cpu(i) {
  98                 struct pcpu_sw_netstats *br_dev_stats;
  99                 br_dev_stats = per_cpu_ptr(br->stats, i);
 100                 u64_stats_init(&br_dev_stats->syncp);
 101         }
 102
 103         return 0;
 104 }
 105
 106 static int br_dev_open(struct net_device *dev)
 107 {
 108         struct net_bridge *br = netdev_priv(dev);
 109
 110         netdev_update_features(dev);
 111         netif_start_queue(dev);
 112         br_stp_enable_bridge(br);
 113         br_multicast_open(br);
 114
 115         return 0;
 116 }
 117
 118 static void br_dev_set_multicast_list(struct net_device *dev)
 119 {
 120 }
 121
 122 static int br_dev_stop(struct net_device *dev)
 123 {
 124         struct net_bridge *br = netdev_priv(dev);
 125
 126         br_stp_disable_bridge(br);
 127         br_multicast_stop(br);
 128
 129         netif_stop_queue(dev);
 130
 131         return 0;
 132 }
 133
 134 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 135                                                 struct rtnl_link_stats64 *stats)
 136 {
 137         struct net_bridge *br = netdev_priv(dev);
 138         struct pcpu_sw_netstats tmp, sum = { 0 };
 139         unsigned int cpu;
 140
 141         for_each_possible_cpu(cpu) {
 142                 unsigned int start;
 143                 const struct pcpu_sw_netstats *bstats
 144                         = per_cpu_ptr(br->stats, cpu);
 145                 do {
 146                         start = u64_stats_fetch_begin_bh(&bstats->syncp);
 147                         memcpy(&tmp, bstats, sizeof(tmp));
 148                 } while (u64_stats_fetch_retry_bh(&bstats->syncp, start));
 149                 sum.tx_bytes   += tmp.tx_bytes;
 150                 sum.tx_packets += tmp.tx_packets;
 151                 sum.rx_bytes   += tmp.rx_bytes;
 152                 sum.rx_packets += tmp.rx_packets;
 153         }
 154
 155         stats->tx_bytes   = sum.tx_bytes;
 156         stats->tx_packets = sum.tx_packets;
 157         stats->rx_bytes   = sum.rx_bytes;
 158         stats->rx_packets = sum.rx_packets;
 159
 160         return stats;
 161 }
 162
 163 static int br_change_mtu(struct net_device *dev, int new_mtu)
 164 {
 165         struct net_bridge *br = netdev_priv(dev);
 166         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 167                 return -EINVAL;
 168
 169         dev->mtu = new_mtu;
 170
 171 #ifdef CONFIG_BRIDGE_NETFILTER
 172         /* remember the MTU in the rtable for PMTU */
 173         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 174 #endif
 175
 176         return 0;
 177 }
 178
 179 /* Allow setting mac address to any valid ethernet address. */
 180 static int br_set_mac_address(struct net_device *dev, void *p)
 181 {
 182         struct net_bridge *br = netdev_priv(dev);
 183         struct sockaddr *addr = p;
 184
 185         if (!is_valid_ether_addr(addr->sa_data))
 186                 return -EADDRNOTAVAIL;
 187
 188         spin_lock_bh(&br->lock);
 189         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 190                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 191                 br_stp_change_bridge_id(br, addr->sa_data);
 192         }
 193         spin_unlock_bh(&br->lock);
 194
 195         return 0;
 196 }
 197
 198 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 199 {
 200         strlcpy(info->driver, "bridge", sizeof(info->driver));
 201         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 202         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 203         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 204 }
 205
 206 static netdev_features_t br_fix_features(struct net_device *dev,
 207         netdev_features_t features)
 208 {
 209         struct net_bridge *br = netdev_priv(dev);
 210
 211         return br_features_recompute(br, features);
 212 }
 213
 214 #ifdef CONFIG_NET_POLL_CONTROLLER
 215 static void br_poll_controller(struct net_device *br_dev)
 216 {
 217 }
 218
 219 static void br_netpoll_cleanup(struct net_device *dev)
 220 {
 221         struct net_bridge *br = netdev_priv(dev);
 222         struct net_bridge_port *p;
 223
 224         list_for_each_entry(p, &br->port_list, list)
 225                 br_netpoll_disable(p);
 226 }
 227
 228 static int __br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp)
 229 {
 230         struct netpoll *np;
 231         int err;
 232
 233         np = kzalloc(sizeof(*p->np), gfp);
 234         if (!np)
 235                 return -ENOMEM;
 236
 237         err = __netpoll_setup(np, p->dev, gfp);
 238         if (err) {
 239                 kfree(np);
 240                 return err;
 241         }
 242
 243         p->np = np;
 244         return err;
 245 }
 246
 247 int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp)
 248 {
 249         if (!p->br->dev->npinfo)
 250                 return 0;
 251
 252         return __br_netpoll_enable(p, gfp);
 253 }
 254
 255 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni,
 256                             gfp_t gfp)
 257 {
 258         struct net_bridge *br = netdev_priv(dev);
 259         struct net_bridge_port *p;
 260         int err = 0;
 261
 262         list_for_each_entry(p, &br->port_list, list) {
 263                 if (!p->dev)
 264                         continue;
 265                 err = __br_netpoll_enable(p, gfp);
 266                 if (err)
 267                         goto fail;
 268         }
 269
 270 out:
 271         return err;
 272
 273 fail:
 274         br_netpoll_cleanup(dev);
 275         goto out;
 276 }
 277
 278 void br_netpoll_disable(struct net_bridge_port *p)
 279 {
 280         struct netpoll *np = p->np;
 281
 282         if (!np)
 283                 return;
 284
 285         p->np = NULL;
 286
 287         __netpoll_free_async(np);
 288 }
 289
 290 #endif
 291
 292 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 293
 294 {
 295         struct net_bridge *br = netdev_priv(dev);
 296
 297         return br_add_if(br, slave_dev);
 298 }
 299
 300 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 301 {
 302         struct net_bridge *br = netdev_priv(dev);
 303
 304         return br_del_if(br, slave_dev);
 305 }
 306
 307 static const struct ethtool_ops br_ethtool_ops = {
 308         .get_drvinfo    = br_getinfo,
 309         .get_link       = ethtool_op_get_link,
 310 };
 311
 312 static const struct net_device_ops br_netdev_ops = {
 313         .ndo_open                = br_dev_open,
 314         .ndo_stop                = br_dev_stop,
 315         .ndo_init                = br_dev_init,
 316         .ndo_start_xmit          = br_dev_xmit,
 317         .ndo_get_stats64         = br_get_stats64,
 318         .ndo_set_mac_address     = br_set_mac_address,
 319         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 320         .ndo_change_mtu          = br_change_mtu,
 321         .ndo_do_ioctl            = br_dev_ioctl,
 322 #ifdef CONFIG_NET_POLL_CONTROLLER
 323         .ndo_netpoll_setup       = br_netpoll_setup,
 324         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 325         .ndo_poll_controller     = br_poll_controller,
 326 #endif
 327         .ndo_add_slave           = br_add_slave,
 328         .ndo_del_slave           = br_del_slave,
 329         .ndo_fix_features        = br_fix_features,
 330         .ndo_fdb_add             = br_fdb_add,
 331         .ndo_fdb_del             = br_fdb_delete,
 332         .ndo_fdb_dump            = br_fdb_dump,
 333         .ndo_bridge_getlink      = br_getlink,
 334         .ndo_bridge_setlink      = br_setlink,
 335         .ndo_bridge_dellink      = br_dellink,
 336 };
 337
 338 static void br_dev_free(struct net_device *dev)
 339 {
 340         struct net_bridge *br = netdev_priv(dev);
 341
 342         free_percpu(br->stats);
 343         free_netdev(dev);
 344 }
 345
 346 static struct device_type br_type = {
 347         .name   = "bridge",
 348 };
 349
 350 void br_dev_setup(struct net_device *dev)
 351 {
 352         struct net_bridge *br = netdev_priv(dev);
 353
 354         eth_hw_addr_random(dev);
 355         ether_setup(dev);
 356
 357         dev->netdev_ops = &br_netdev_ops;
 358         dev->destructor = br_dev_free;
 359         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 360         SET_NETDEV_DEVTYPE(dev, &br_type);
 361         dev->tx_queue_len = 0;
 362         dev->priv_flags = IFF_EBRIDGE;
 363
 364         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 365                         NETIF_F_HW_VLAN_CTAG_TX;
 366         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX;
 367         dev->vlan_features = COMMON_FEATURES;
 368
 369         br->dev = dev;
 370         spin_lock_init(&br->lock);
 371         INIT_LIST_HEAD(&br->port_list);
 372         spin_lock_init(&br->hash_lock);
 373
 374         br->bridge_id.prio[0] = 0x80;
 375         br->bridge_id.prio[1] = 0x00;
 376
 377         memcpy(br->group_addr, eth_reserved_addr_base, ETH_ALEN);
 378
 379         br->stp_enabled = BR_NO_STP;
 380         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 381
 382         br->designated_root = br->bridge_id;
 383         br->bridge_max_age = br->max_age = 20 * HZ;
 384         br->bridge_hello_time = br->hello_time = 2 * HZ;
 385         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 386         br->ageing_time = 300 * HZ;
 387
 388         br_netfilter_rtable_init(br);
 389         br_stp_timer_init(br);
 390         br_multicast_init(br);
 391 }