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