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         u16 vid = 0;
  34
  35         rcu_read_lock();
  36 #ifdef CONFIG_BRIDGE_NETFILTER
  37         if (skb->nf_bridge && (skb->nf_bridge->mask & BRNF_BRIDGED_DNAT)) {
  38                 br_nf_pre_routing_finish_bridge_slow(skb);
  39                 rcu_read_unlock();
  40                 return NETDEV_TX_OK;
  41         }
  42 #endif
  43
  44         u64_stats_update_begin(&brstats->syncp);
  45         brstats->tx_packets++;
  46         brstats->tx_bytes += skb->len;
  47         u64_stats_update_end(&brstats->syncp);
  48
  49         if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid))
  50                 goto out;
  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 (is_broadcast_ether_addr(dest))
  58                 br_flood_deliver(br, skb);
  59         else if (is_multicast_ether_addr(dest)) {
  60                 if (unlikely(netpoll_tx_running(dev))) {
  61                         br_flood_deliver(br, skb);
  62                         goto out;
  63                 }
  64                 if (br_multicast_rcv(br, NULL, skb)) {
  65                         kfree_skb(skb);
  66                         goto out;
  67                 }
  68
  69                 mdst = br_mdb_get(br, skb, vid);
  70                 if (mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb))
  71                         br_multicast_deliver(mdst, skb);
  72                 else
  73                         br_flood_deliver(br, skb);
  74         } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL)
  75                 br_deliver(dst->dst, skb);
  76         else
  77                 br_flood_deliver(br, skb);
  78
  79 out:
  80         rcu_read_unlock();
  81         return NETDEV_TX_OK;
  82 }
  83
  84 static int br_dev_init(struct net_device *dev)
  85 {
  86         struct net_bridge *br = netdev_priv(dev);
  87
  88         br->stats = alloc_percpu(struct br_cpu_netstats);
  89         if (!br->stats)
  90                 return -ENOMEM;
  91
  92         return 0;
  93 }
  94
  95 static int br_dev_open(struct net_device *dev)
  96 {
  97         struct net_bridge *br = netdev_priv(dev);
  98
  99         netdev_update_features(dev);
 100         netif_start_queue(dev);
 101         br_stp_enable_bridge(br);
 102         br_multicast_open(br);
 103
 104         return 0;
 105 }
 106
 107 static void br_dev_set_multicast_list(struct net_device *dev)
 108 {
 109 }
 110
 111 static int br_dev_stop(struct net_device *dev)
 112 {
 113         struct net_bridge *br = netdev_priv(dev);
 114
 115         br_stp_disable_bridge(br);
 116         br_multicast_stop(br);
 117
 118         netif_stop_queue(dev);
 119
 120         return 0;
 121 }
 122
 123 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 124                                                 struct rtnl_link_stats64 *stats)
 125 {
 126         struct net_bridge *br = netdev_priv(dev);
 127         struct br_cpu_netstats tmp, sum = { 0 };
 128         unsigned int cpu;
 129
 130         for_each_possible_cpu(cpu) {
 131                 unsigned int start;
 132                 const struct br_cpu_netstats *bstats
 133                         = per_cpu_ptr(br->stats, cpu);
 134                 do {
 135                         start = u64_stats_fetch_begin_bh(&bstats->syncp);
 136                         memcpy(&tmp, bstats, sizeof(tmp));
 137                 } while (u64_stats_fetch_retry_bh(&bstats->syncp, start));
 138                 sum.tx_bytes   += tmp.tx_bytes;
 139                 sum.tx_packets += tmp.tx_packets;
 140                 sum.rx_bytes   += tmp.rx_bytes;
 141                 sum.rx_packets += tmp.rx_packets;
 142         }
 143
 144         stats->tx_bytes   = sum.tx_bytes;
 145         stats->tx_packets = sum.tx_packets;
 146         stats->rx_bytes   = sum.rx_bytes;
 147         stats->rx_packets = sum.rx_packets;
 148
 149         return stats;
 150 }
 151
 152 static int br_change_mtu(struct net_device *dev, int new_mtu)
 153 {
 154         struct net_bridge *br = netdev_priv(dev);
 155         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 156                 return -EINVAL;
 157
 158         dev->mtu = new_mtu;
 159
 160 #ifdef CONFIG_BRIDGE_NETFILTER
 161         /* remember the MTU in the rtable for PMTU */
 162         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 163 #endif
 164
 165         return 0;
 166 }
 167
 168 /* Allow setting mac address to any valid ethernet address. */
 169 static int br_set_mac_address(struct net_device *dev, void *p)
 170 {
 171         struct net_bridge *br = netdev_priv(dev);
 172         struct sockaddr *addr = p;
 173
 174         if (!is_valid_ether_addr(addr->sa_data))
 175                 return -EADDRNOTAVAIL;
 176
 177         spin_lock_bh(&br->lock);
 178         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 179                 memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
 180                 br_fdb_change_mac_address(br, addr->sa_data);
 181                 br_stp_change_bridge_id(br, addr->sa_data);
 182         }
 183         spin_unlock_bh(&br->lock);
 184
 185         return 0;
 186 }
 187
 188 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 189 {
 190         strlcpy(info->driver, "bridge", sizeof(info->driver));
 191         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 192         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 193         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 194 }
 195
 196 static netdev_features_t br_fix_features(struct net_device *dev,
 197         netdev_features_t features)
 198 {
 199         struct net_bridge *br = netdev_priv(dev);
 200
 201         return br_features_recompute(br, features);
 202 }
 203
 204 #ifdef CONFIG_NET_POLL_CONTROLLER
 205 static void br_poll_controller(struct net_device *br_dev)
 206 {
 207 }
 208
 209 static void br_netpoll_cleanup(struct net_device *dev)
 210 {
 211         struct net_bridge *br = netdev_priv(dev);
 212         struct net_bridge_port *p;
 213
 214         list_for_each_entry(p, &br->port_list, list)
 215                 br_netpoll_disable(p);
 216 }
 217
 218 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni,
 219                             gfp_t gfp)
 220 {
 221         struct net_bridge *br = netdev_priv(dev);
 222         struct net_bridge_port *p;
 223         int err = 0;
 224
 225         list_for_each_entry(p, &br->port_list, list) {
 226                 if (!p->dev)
 227                         continue;
 228                 err = br_netpoll_enable(p, gfp);
 229                 if (err)
 230                         goto fail;
 231         }
 232
 233 out:
 234         return err;
 235
 236 fail:
 237         br_netpoll_cleanup(dev);
 238         goto out;
 239 }
 240
 241 int br_netpoll_enable(struct net_bridge_port *p, gfp_t gfp)
 242 {
 243         struct netpoll *np;
 244         int err = 0;
 245
 246         np = kzalloc(sizeof(*p->np), gfp);
 247         err = -ENOMEM;
 248         if (!np)
 249                 goto out;
 250
 251         err = __netpoll_setup(np, p->dev, gfp);
 252         if (err) {
 253                 kfree(np);
 254                 goto out;
 255         }
 256
 257         p->np = np;
 258
 259 out:
 260         return err;
 261 }
 262
 263 void br_netpoll_disable(struct net_bridge_port *p)
 264 {
 265         struct netpoll *np = p->np;
 266
 267         if (!np)
 268                 return;
 269
 270         p->np = NULL;
 271
 272         __netpoll_free_async(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         .ndo_fdb_add             = br_fdb_add,
 316         .ndo_fdb_del             = br_fdb_delete,
 317         .ndo_fdb_dump            = br_fdb_dump,
 318         .ndo_bridge_getlink      = br_getlink,
 319         .ndo_bridge_setlink      = br_setlink,
 320         .ndo_bridge_dellink      = br_dellink,
 321 };
 322
 323 static void br_dev_free(struct net_device *dev)
 324 {
 325         struct net_bridge *br = netdev_priv(dev);
 326
 327         free_percpu(br->stats);
 328         free_netdev(dev);
 329 }
 330
 331 static struct device_type br_type = {
 332         .name   = "bridge",
 333 };
 334
 335 void br_dev_setup(struct net_device *dev)
 336 {
 337         struct net_bridge *br = netdev_priv(dev);
 338
 339         eth_hw_addr_random(dev);
 340         ether_setup(dev);
 341
 342         dev->netdev_ops = &br_netdev_ops;
 343         dev->destructor = br_dev_free;
 344         SET_ETHTOOL_OPS(dev, &br_ethtool_ops);
 345         SET_NETDEV_DEVTYPE(dev, &br_type);
 346         dev->tx_queue_len = 0;
 347         dev->priv_flags = IFF_EBRIDGE;
 348
 349         dev->features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 350                         NETIF_F_GSO_MASK | NETIF_F_HW_CSUM | NETIF_F_LLTX |
 351                         NETIF_F_NETNS_LOCAL | NETIF_F_HW_VLAN_TX;
 352         dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HIGHDMA |
 353                            NETIF_F_GSO_MASK | NETIF_F_HW_CSUM |
 354                            NETIF_F_HW_VLAN_TX;
 355
 356         br->dev = dev;
 357         spin_lock_init(&br->lock);
 358         INIT_LIST_HEAD(&br->port_list);
 359         spin_lock_init(&br->hash_lock);
 360
 361         br->bridge_id.prio[0] = 0x80;
 362         br->bridge_id.prio[1] = 0x00;
 363
 364         memcpy(br->group_addr, eth_reserved_addr_base, ETH_ALEN);
 365
 366         br->stp_enabled = BR_NO_STP;
 367         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 368
 369         br->designated_root = br->bridge_id;
 370         br->bridge_max_age = br->max_age = 20 * HZ;
 371         br->bridge_hello_time = br->hello_time = 2 * HZ;
 372         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 373         br->ageing_time = 300 * HZ;
 374
 375         br_netfilter_rtable_init(br);
 376         br_stp_timer_init(br);
 377         br_multicast_init(br);
 378 }