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 #if IS_ENABLED(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 err;
  92
  93         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
  94         if (!br->stats)
  95                 return -ENOMEM;
  96
  97         err = br_vlan_init(br);
  98         if (err)
  99                 free_percpu(br->stats);
 100
 101         return err;
 102 }
 103
 104 static int br_dev_open(struct net_device *dev)
 105 {
 106         struct net_bridge *br = netdev_priv(dev);
 107
 108         netdev_update_features(dev);
 109         netif_start_queue(dev);
 110         br_stp_enable_bridge(br);
 111         br_multicast_open(br);
 112
 113         return 0;
 114 }
 115
 116 static void br_dev_set_multicast_list(struct net_device *dev)
 117 {
 118 }
 119
 120 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 121 {
 122         if (change & IFF_PROMISC)
 123                 br_manage_promisc(netdev_priv(dev));
 124 }
 125
 126 static int br_dev_stop(struct net_device *dev)
 127 {
 128         struct net_bridge *br = netdev_priv(dev);
 129
 130         br_stp_disable_bridge(br);
 131         br_multicast_stop(br);
 132
 133         netif_stop_queue(dev);
 134
 135         return 0;
 136 }
 137
 138 static struct rtnl_link_stats64 *br_get_stats64(struct net_device *dev,
 139                                                 struct rtnl_link_stats64 *stats)
 140 {
 141         struct net_bridge *br = netdev_priv(dev);
 142         struct pcpu_sw_netstats tmp, sum = { 0 };
 143         unsigned int cpu;
 144
 145         for_each_possible_cpu(cpu) {
 146                 unsigned int start;
 147                 const struct pcpu_sw_netstats *bstats
 148                         = per_cpu_ptr(br->stats, cpu);
 149                 do {
 150                         start = u64_stats_fetch_begin_irq(&bstats->syncp);
 151                         memcpy(&tmp, bstats, sizeof(tmp));
 152                 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
 153                 sum.tx_bytes   += tmp.tx_bytes;
 154                 sum.tx_packets += tmp.tx_packets;
 155                 sum.rx_bytes   += tmp.rx_bytes;
 156                 sum.rx_packets += tmp.rx_packets;
 157         }
 158
 159         stats->tx_bytes   = sum.tx_bytes;
 160         stats->tx_packets = sum.tx_packets;
 161         stats->rx_bytes   = sum.rx_bytes;
 162         stats->rx_packets = sum.rx_packets;
 163
 164         return stats;
 165 }
 166
 167 static int br_change_mtu(struct net_device *dev, int new_mtu)
 168 {
 169         struct net_bridge *br = netdev_priv(dev);
 170         if (new_mtu < 68 || new_mtu > br_min_mtu(br))
 171                 return -EINVAL;
 172
 173         dev->mtu = new_mtu;
 174
 175 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 176         /* remember the MTU in the rtable for PMTU */
 177         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 178 #endif
 179
 180         return 0;
 181 }
 182
 183 /* Allow setting mac address to any valid ethernet address. */
 184 static int br_set_mac_address(struct net_device *dev, void *p)
 185 {
 186         struct net_bridge *br = netdev_priv(dev);
 187         struct sockaddr *addr = p;
 188
 189         if (!is_valid_ether_addr(addr->sa_data))
 190                 return -EADDRNOTAVAIL;
 191
 192         spin_lock_bh(&br->lock);
 193         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 194                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 195                 br_stp_change_bridge_id(br, addr->sa_data);
 196         }
 197         spin_unlock_bh(&br->lock);
 198
 199         return 0;
 200 }
 201
 202 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 203 {
 204         strlcpy(info->driver, "bridge", sizeof(info->driver));
 205         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 206         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 207         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 208 }
 209
 210 static netdev_features_t br_fix_features(struct net_device *dev,
 211         netdev_features_t features)
 212 {
 213         struct net_bridge *br = netdev_priv(dev);
 214
 215         return br_features_recompute(br, features);
 216 }
 217
 218 #ifdef CONFIG_NET_POLL_CONTROLLER
 219 static void br_poll_controller(struct net_device *br_dev)
 220 {
 221 }
 222
 223 static void br_netpoll_cleanup(struct net_device *dev)
 224 {
 225         struct net_bridge *br = netdev_priv(dev);
 226         struct net_bridge_port *p;
 227
 228         list_for_each_entry(p, &br->port_list, list)
 229                 br_netpoll_disable(p);
 230 }
 231
 232 static int __br_netpoll_enable(struct net_bridge_port *p)
 233 {
 234         struct netpoll *np;
 235         int err;
 236
 237         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 238         if (!np)
 239                 return -ENOMEM;
 240
 241         err = __netpoll_setup(np, p->dev);
 242         if (err) {
 243                 kfree(np);
 244                 return err;
 245         }
 246
 247         p->np = np;
 248         return err;
 249 }
 250
 251 int br_netpoll_enable(struct net_bridge_port *p)
 252 {
 253         if (!p->br->dev->npinfo)
 254                 return 0;
 255
 256         return __br_netpoll_enable(p);
 257 }
 258
 259 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 260 {
 261         struct net_bridge *br = netdev_priv(dev);
 262         struct net_bridge_port *p;
 263         int err = 0;
 264
 265         list_for_each_entry(p, &br->port_list, list) {
 266                 if (!p->dev)
 267                         continue;
 268                 err = __br_netpoll_enable(p);
 269                 if (err)
 270                         goto fail;
 271         }
 272
 273 out:
 274         return err;
 275
 276 fail:
 277         br_netpoll_cleanup(dev);
 278         goto out;
 279 }
 280
 281 void br_netpoll_disable(struct net_bridge_port *p)
 282 {
 283         struct netpoll *np = p->np;
 284
 285         if (!np)
 286                 return;
 287
 288         p->np = NULL;
 289
 290         __netpoll_free_async(np);
 291 }
 292
 293 #endif
 294
 295 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 296
 297 {
 298         struct net_bridge *br = netdev_priv(dev);
 299
 300         return br_add_if(br, slave_dev);
 301 }
 302
 303 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 304 {
 305         struct net_bridge *br = netdev_priv(dev);
 306
 307         return br_del_if(br, slave_dev);
 308 }
 309
 310 static const struct ethtool_ops br_ethtool_ops = {
 311         .get_drvinfo    = br_getinfo,
 312         .get_link       = ethtool_op_get_link,
 313 };
 314
 315 static const struct net_device_ops br_netdev_ops = {
 316         .ndo_open                = br_dev_open,
 317         .ndo_stop                = br_dev_stop,
 318         .ndo_init                = br_dev_init,
 319         .ndo_start_xmit          = br_dev_xmit,
 320         .ndo_get_stats64         = br_get_stats64,
 321         .ndo_set_mac_address     = br_set_mac_address,
 322         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 323         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 324         .ndo_change_mtu          = br_change_mtu,
 325         .ndo_do_ioctl            = br_dev_ioctl,
 326 #ifdef CONFIG_NET_POLL_CONTROLLER
 327         .ndo_netpoll_setup       = br_netpoll_setup,
 328         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 329         .ndo_poll_controller     = br_poll_controller,
 330 #endif
 331         .ndo_add_slave           = br_add_slave,
 332         .ndo_del_slave           = br_del_slave,
 333         .ndo_fix_features        = br_fix_features,
 334         .ndo_fdb_add             = br_fdb_add,
 335         .ndo_fdb_del             = br_fdb_delete,
 336         .ndo_fdb_dump            = br_fdb_dump,
 337         .ndo_bridge_getlink      = br_getlink,
 338         .ndo_bridge_setlink      = br_setlink,
 339         .ndo_bridge_dellink      = br_dellink,
 340 };
 341
 342 static void br_dev_free(struct net_device *dev)
 343 {
 344         struct net_bridge *br = netdev_priv(dev);
 345
 346         free_percpu(br->stats);
 347         free_netdev(dev);
 348 }
 349
 350 static struct device_type br_type = {
 351         .name   = "bridge",
 352 };
 353
 354 void br_dev_setup(struct net_device *dev)
 355 {
 356         struct net_bridge *br = netdev_priv(dev);
 357
 358         eth_hw_addr_random(dev);
 359         ether_setup(dev);
 360
 361         dev->netdev_ops = &br_netdev_ops;
 362         dev->destructor = br_dev_free;
 363         dev->ethtool_ops = &br_ethtool_ops;
 364         SET_NETDEV_DEVTYPE(dev, &br_type);
 365         dev->tx_queue_len = 0;
 366         dev->priv_flags = IFF_EBRIDGE;
 367
 368         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 369                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 370         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 371                            NETIF_F_HW_VLAN_STAG_TX;
 372         dev->vlan_features = COMMON_FEATURES;
 373
 374         br->dev = dev;
 375         spin_lock_init(&br->lock);
 376         INIT_LIST_HEAD(&br->port_list);
 377         spin_lock_init(&br->hash_lock);
 378
 379         br->bridge_id.prio[0] = 0x80;
 380         br->bridge_id.prio[1] = 0x00;
 381
 382         ether_addr_copy(br->group_addr, eth_reserved_addr_base);
 383
 384         br->stp_enabled = BR_NO_STP;
 385         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 386         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 387
 388         br->designated_root = br->bridge_id;
 389         br->bridge_max_age = br->max_age = 20 * HZ;
 390         br->bridge_hello_time = br->hello_time = 2 * HZ;
 391         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 392         br->ageing_time = 300 * HZ;
 393
 394         br_netfilter_rtable_init(br);
 395         br_stp_timer_init(br);
 396         br_multicast_init(br);
 397 }