net/bridge/br_device.c

   1 /*
   2  *      Device handling code
   3  *      Linux ethernet bridge
   4  *
   5  *      Authors:
   6  *      Lennert Buytenhek               <[email protected]>
   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         if (br_nf_prerouting_finish_bridge(skb)) {
  40                 rcu_read_unlock();
  41                 return NETDEV_TX_OK;
  42         }
  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         BR_INPUT_SKB_CB(skb)->brdev = dev;
  50
  51         skb_reset_mac_header(skb);
  52         skb_pull(skb, ETH_HLEN);
  53
  54         if (!br_allowed_ingress(br, br_get_vlan_info(br), skb, &vid))
  55                 goto out;
  56
  57         if (is_broadcast_ether_addr(dest))
  58                 br_flood_deliver(br, skb, false);
  59         else if (is_multicast_ether_addr(dest)) {
  60                 if (unlikely(netpoll_tx_running(dev))) {
  61                         br_flood_deliver(br, skb, false);
  62                         goto out;
  63                 }
  64                 if (br_multicast_rcv(br, NULL, skb, vid)) {
  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_querier_exists(br, eth_hdr(skb)))
  72                         br_multicast_deliver(mdst, skb);
  73                 else
  74                         br_flood_deliver(br, skb, false);
  75         } else if ((dst = __br_fdb_get(br, dest, vid)) != NULL)
  76                 br_deliver(dst->dst, skb);
  77         else
  78                 br_flood_deliver(br, skb, true);
  79
  80 out:
  81         rcu_read_unlock();
  82         return NETDEV_TX_OK;
  83 }
  84
  85 static int br_dev_init(struct net_device *dev)
  86 {
  87         struct net_bridge *br = netdev_priv(dev);
  88         int err;
  89
  90         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
  91         if (!br->stats)
  92                 return -ENOMEM;
  93
  94         err = br_vlan_init(br);
  95         if (err)
  96                 free_percpu(br->stats);
  97
  98         return err;
  99 }
 100
 101 static int br_dev_open(struct net_device *dev)
 102 {
 103         struct net_bridge *br = netdev_priv(dev);
 104
 105         netdev_update_features(dev);
 106         netif_start_queue(dev);
 107         br_stp_enable_bridge(br);
 108         br_multicast_open(br);
 109
 110         return 0;
 111 }
 112
 113 static void br_dev_set_multicast_list(struct net_device *dev)
 114 {
 115 }
 116
 117 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 118 {
 119         if (change & IFF_PROMISC)
 120                 br_manage_promisc(netdev_priv(dev));
 121 }
 122
 123 static int br_dev_stop(struct net_device *dev)
 124 {
 125         struct net_bridge *br = netdev_priv(dev);
 126
 127         br_stp_disable_bridge(br);
 128         br_multicast_stop(br);
 129
 130         netif_stop_queue(dev);
 131
 132         return 0;
 133 }
 134
 135 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 136                                                 struct rtnl_link_stats64 *stats)
 137 {
 138         struct net_bridge *br = netdev_priv(dev);
 139         struct pcpu_sw_netstats tmp, sum = { 0 };
 140         unsigned int cpu;
 141
 142         for_each_possible_cpu(cpu) {
 143                 unsigned int start;
 144                 const struct pcpu_sw_netstats *bstats
 145                         = per_cpu_ptr(br->stats, cpu);
 146                 do {
 147                         start = u64_stats_fetch_begin_irq(&bstats->syncp);
 148                         memcpy(&tmp, bstats, sizeof(tmp));
 149                 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
 150                 sum.tx_bytes   += tmp.tx_bytes;
 151                 sum.tx_packets += tmp.tx_packets;
 152                 sum.rx_bytes   += tmp.rx_bytes;
 153                 sum.rx_packets += tmp.rx_packets;
 154         }
 155
 156         stats->tx_bytes   = sum.tx_bytes;
 157         stats->tx_packets = sum.tx_packets;
 158         stats->rx_bytes   = sum.rx_bytes;
 159         stats->rx_packets = sum.rx_packets;
 160
 161         return stats;
 162 }
 163
 164 static int br_change_mtu(struct net_device *dev, int new_mtu)
 165 {
 166         struct net_bridge *br = netdev_priv(dev);
 167         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 168                 return -EINVAL;
 169
 170         dev->mtu = new_mtu;
 171
 172 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 173         /* remember the MTU in the rtable for PMTU */
 174         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 175 #endif
 176
 177         return 0;
 178 }
 179
 180 /* Allow setting mac address to any valid ethernet address. */
 181 static int br_set_mac_address(struct net_device *dev, void *p)
 182 {
 183         struct net_bridge *br = netdev_priv(dev);
 184         struct sockaddr *addr = p;
 185
 186         if (!is_valid_ether_addr(addr->sa_data))
 187                 return -EADDRNOTAVAIL;
 188
 189         spin_lock_bh(&br->lock);
 190         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 191                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 192                 br_stp_change_bridge_id(br, addr->sa_data);
 193         }
 194         spin_unlock_bh(&br->lock);
 195
 196         return 0;
 197 }
 198
 199 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 200 {
 201         strlcpy(info->driver, "bridge", sizeof(info->driver));
 202         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 203         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 204         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 205 }
 206
 207 static netdev_features_t br_fix_features(struct net_device *dev,
 208         netdev_features_t features)
 209 {
 210         struct net_bridge *br = netdev_priv(dev);
 211
 212         return br_features_recompute(br, features);
 213 }
 214
 215 #ifdef CONFIG_NET_POLL_CONTROLLER
 216 static void br_poll_controller(struct net_device *br_dev)
 217 {
 218 }
 219
 220 static void br_netpoll_cleanup(struct net_device *dev)
 221 {
 222         struct net_bridge *br = netdev_priv(dev);
 223         struct net_bridge_port *p;
 224
 225         list_for_each_entry(p, &br->port_list, list)
 226                 br_netpoll_disable(p);
 227 }
 228
 229 static int __br_netpoll_enable(struct net_bridge_port *p)
 230 {
 231         struct netpoll *np;
 232         int err;
 233
 234         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 235         if (!np)
 236                 return -ENOMEM;
 237
 238         err = __netpoll_setup(np, p->dev);
 239         if (err) {
 240                 kfree(np);
 241                 return err;
 242         }
 243
 244         p->np = np;
 245         return err;
 246 }
 247
 248 int br_netpoll_enable(struct net_bridge_port *p)
 249 {
 250         if (!p->br->dev->npinfo)
 251                 return 0;
 252
 253         return __br_netpoll_enable(p);
 254 }
 255
 256 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 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);
 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_rx_flags     = br_dev_change_rx_flags,
 321         .ndo_change_mtu          = br_change_mtu,
 322         .ndo_do_ioctl            = br_dev_ioctl,
 323 #ifdef CONFIG_NET_POLL_CONTROLLER
 324         .ndo_netpoll_setup       = br_netpoll_setup,
 325         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 326         .ndo_poll_controller     = br_poll_controller,
 327 #endif
 328         .ndo_add_slave           = br_add_slave,
 329         .ndo_del_slave           = br_del_slave,
 330         .ndo_fix_features        = br_fix_features,
 331         .ndo_fdb_add             = br_fdb_add,
 332         .ndo_fdb_del             = br_fdb_delete,
 333         .ndo_fdb_dump            = br_fdb_dump,
 334         .ndo_bridge_getlink      = br_getlink,
 335         .ndo_bridge_setlink      = br_setlink,
 336         .ndo_bridge_dellink      = br_dellink,
 337 };
 338
 339 static void br_dev_free(struct net_device *dev)
 340 {
 341         struct net_bridge *br = netdev_priv(dev);
 342
 343         free_percpu(br->stats);
 344         free_netdev(dev);
 345 }
 346
 347 static struct device_type br_type = {
 348         .name   = "bridge",
 349 };
 350
 351 void br_dev_setup(struct net_device *dev)
 352 {
 353         struct net_bridge *br = netdev_priv(dev);
 354
 355         eth_hw_addr_random(dev);
 356         ether_setup(dev);
 357
 358         dev->netdev_ops = &br_netdev_ops;
 359         dev->destructor = br_dev_free;
 360         dev->ethtool_ops = &br_ethtool_ops;
 361         SET_NETDEV_DEVTYPE(dev, &br_type);
 362         dev->tx_queue_len = 0;
 363         dev->priv_flags = IFF_EBRIDGE;
 364
 365         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 366                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 367         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 368                            NETIF_F_HW_VLAN_STAG_TX;
 369         dev->vlan_features = COMMON_FEATURES;
 370
 371         br->dev = dev;
 372         spin_lock_init(&br->lock);
 373         INIT_LIST_HEAD(&br->port_list);
 374         spin_lock_init(&br->hash_lock);
 375
 376         br->bridge_id.prio[0] = 0x80;
 377         br->bridge_id.prio[1] = 0x00;
 378
 379         ether_addr_copy(br->group_addr, eth_reserved_addr_base);
 380
 381         br->stp_enabled = BR_NO_STP;
 382         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 383         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 384
 385         br->designated_root = br->bridge_id;
 386         br->bridge_max_age = br->max_age = 20 * HZ;
 387         br->bridge_hello_time = br->hello_time = 2 * HZ;
 388         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 389         br->ageing_time = 300 * HZ;
 390
 391         br_netfilter_rtable_init(br);
 392         br_stp_timer_init(br);
 393         br_multicast_init(br);
 394 }