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 <linux/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 const struct nf_br_ops __rcu *nf_br_ops __read_mostly;
  29 EXPORT_SYMBOL_GPL(nf_br_ops);
  30
  31 static struct lock_class_key bridge_netdev_addr_lock_key;
  32
  33 /* net device transmit always called with BH disabled */
  34 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
  35 {
  36         struct net_bridge *br = netdev_priv(dev);
  37         struct net_bridge_fdb_entry *dst;
  38         struct net_bridge_mdb_entry *mdst;
  39         struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);
  40         const struct nf_br_ops *nf_ops;
  41         const unsigned char *dest;
  42         u16 vid = 0;
  43
  44         rcu_read_lock();
  45         nf_ops = rcu_dereference(nf_br_ops);
  46         if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
  47                 rcu_read_unlock();
  48                 return NETDEV_TX_OK;
  49         }
  50
  51         u64_stats_update_begin(&brstats->syncp);
  52         brstats->tx_packets++;
  53         brstats->tx_bytes += skb->len;
  54         u64_stats_update_end(&brstats->syncp);
  55
  56         br_switchdev_frame_unmark(skb);
  57         BR_INPUT_SKB_CB(skb)->brdev = dev;
  58
  59         skb_reset_mac_header(skb);
  60         skb_pull(skb, ETH_HLEN);
  61
  62         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid))
  63                 goto out;
  64
  65         dest = eth_hdr(skb)->h_dest;
  66         if (is_broadcast_ether_addr(dest)) {
  67                 br_flood(br, skb, BR_PKT_BROADCAST, false, true);
  68         } else if (is_multicast_ether_addr(dest)) {
  69                 if (unlikely(netpoll_tx_running(dev))) {
  70                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  71                         goto out;
  72                 }
  73                 if (br_multicast_rcv(br, NULL, skb, vid)) {
  74                         kfree_skb(skb);
  75                         goto out;
  76                 }
  77
  78                 mdst = br_mdb_get(br, skb, vid);
  79                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
  80                     br_multicast_querier_exists(br, eth_hdr(skb)))
  81                         br_multicast_flood(mdst, skb, false, true);
  82                 else
  83                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  84         } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
  85                 br_forward(dst->dst, skb, false, true);
  86         } else {
  87                 br_flood(br, skb, BR_PKT_UNICAST, false, true);
  88         }
  89 out:
  90         rcu_read_unlock();
  91         return NETDEV_TX_OK;
  92 }
  93
  94 static void br_set_lockdep_class(struct net_device *dev)
  95 {
  96         lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key);
  97 }
  98
  99 static int br_dev_init(struct net_device *dev)
 100 {
 101         struct net_bridge *br = netdev_priv(dev);
 102         int err;
 103
 104         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 105         if (!br->stats)
 106                 return -ENOMEM;
 107
 108         err = br_vlan_init(br);
 109         if (err) {
 110                 free_percpu(br->stats);
 111                 return err;
 112         }
 113
 114         err = br_multicast_init_stats(br);
 115         if (err) {
 116                 free_percpu(br->stats);
 117                 br_vlan_flush(br);
 118         }
 119         br_set_lockdep_class(dev);
 120
 121         return err;
 122 }
 123
 124 static void br_dev_uninit(struct net_device *dev)
 125 {
 126         struct net_bridge *br = netdev_priv(dev);
 127
 128         br_multicast_dev_del(br);
 129         br_multicast_uninit_stats(br);
 130         br_vlan_flush(br);
 131         free_percpu(br->stats);
 132 }
 133
 134 static int br_dev_open(struct net_device *dev)
 135 {
 136         struct net_bridge *br = netdev_priv(dev);
 137
 138         netdev_update_features(dev);
 139         netif_start_queue(dev);
 140         br_stp_enable_bridge(br);
 141         br_multicast_open(br);
 142
 143         return 0;
 144 }
 145
 146 static void br_dev_set_multicast_list(struct net_device *dev)
 147 {
 148 }
 149
 150 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 151 {
 152         if (change & IFF_PROMISC)
 153                 br_manage_promisc(netdev_priv(dev));
 154 }
 155
 156 static int br_dev_stop(struct net_device *dev)
 157 {
 158         struct net_bridge *br = netdev_priv(dev);
 159
 160         br_stp_disable_bridge(br);
 161         br_multicast_stop(br);
 162
 163         netif_stop_queue(dev);
 164
 165         return 0;
 166 }
 167
 168 static void br_get_stats64(struct net_device *dev,
 169                            struct rtnl_link_stats64 *stats)
 170 {
 171         struct net_bridge *br = netdev_priv(dev);
 172         struct pcpu_sw_netstats tmp, sum = { 0 };
 173         unsigned int cpu;
 174
 175         for_each_possible_cpu(cpu) {
 176                 unsigned int start;
 177                 const struct pcpu_sw_netstats *bstats
 178                         = per_cpu_ptr(br->stats, cpu);
 179                 do {
 180                         start = u64_stats_fetch_begin_irq(&bstats->syncp);
 181                         memcpy(&tmp, bstats, sizeof(tmp));
 182                 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
 183                 sum.tx_bytes   += tmp.tx_bytes;
 184                 sum.tx_packets += tmp.tx_packets;
 185                 sum.rx_bytes   += tmp.rx_bytes;
 186                 sum.rx_packets += tmp.rx_packets;
 187         }
 188
 189         stats->tx_bytes   = sum.tx_bytes;
 190         stats->tx_packets = sum.tx_packets;
 191         stats->rx_bytes   = sum.rx_bytes;
 192         stats->rx_packets = sum.rx_packets;
 193 }
 194
 195 static int br_change_mtu(struct net_device *dev, int new_mtu)
 196 {
 197         struct net_bridge *br = netdev_priv(dev);
 198         if (new_mtu > br_min_mtu(br))
 199                 return -EINVAL;
 200
 201         dev->mtu = new_mtu;
 202
 203 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 204         /* remember the MTU in the rtable for PMTU */
 205         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 206 #endif
 207
 208         return 0;
 209 }
 210
 211 /* Allow setting mac address to any valid ethernet address. */
 212 static int br_set_mac_address(struct net_device *dev, void *p)
 213 {
 214         struct net_bridge *br = netdev_priv(dev);
 215         struct sockaddr *addr = p;
 216
 217         if (!is_valid_ether_addr(addr->sa_data))
 218                 return -EADDRNOTAVAIL;
 219
 220         spin_lock_bh(&br->lock);
 221         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 222                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 223                 br_stp_change_bridge_id(br, addr->sa_data);
 224         }
 225         spin_unlock_bh(&br->lock);
 226
 227         return 0;
 228 }
 229
 230 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 231 {
 232         strlcpy(info->driver, "bridge", sizeof(info->driver));
 233         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 234         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 235         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 236 }
 237
 238 static netdev_features_t br_fix_features(struct net_device *dev,
 239         netdev_features_t features)
 240 {
 241         struct net_bridge *br = netdev_priv(dev);
 242
 243         return br_features_recompute(br, features);
 244 }
 245
 246 #ifdef CONFIG_NET_POLL_CONTROLLER
 247 static void br_poll_controller(struct net_device *br_dev)
 248 {
 249 }
 250
 251 static void br_netpoll_cleanup(struct net_device *dev)
 252 {
 253         struct net_bridge *br = netdev_priv(dev);
 254         struct net_bridge_port *p;
 255
 256         list_for_each_entry(p, &br->port_list, list)
 257                 br_netpoll_disable(p);
 258 }
 259
 260 static int __br_netpoll_enable(struct net_bridge_port *p)
 261 {
 262         struct netpoll *np;
 263         int err;
 264
 265         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 266         if (!np)
 267                 return -ENOMEM;
 268
 269         err = __netpoll_setup(np, p->dev);
 270         if (err) {
 271                 kfree(np);
 272                 return err;
 273         }
 274
 275         p->np = np;
 276         return err;
 277 }
 278
 279 int br_netpoll_enable(struct net_bridge_port *p)
 280 {
 281         if (!p->br->dev->npinfo)
 282                 return 0;
 283
 284         return __br_netpoll_enable(p);
 285 }
 286
 287 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 288 {
 289         struct net_bridge *br = netdev_priv(dev);
 290         struct net_bridge_port *p;
 291         int err = 0;
 292
 293         list_for_each_entry(p, &br->port_list, list) {
 294                 if (!p->dev)
 295                         continue;
 296                 err = __br_netpoll_enable(p);
 297                 if (err)
 298                         goto fail;
 299         }
 300
 301 out:
 302         return err;
 303
 304 fail:
 305         br_netpoll_cleanup(dev);
 306         goto out;
 307 }
 308
 309 void br_netpoll_disable(struct net_bridge_port *p)
 310 {
 311         struct netpoll *np = p->np;
 312
 313         if (!np)
 314                 return;
 315
 316         p->np = NULL;
 317
 318         __netpoll_free_async(np);
 319 }
 320
 321 #endif
 322
 323 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev)
 324
 325 {
 326         struct net_bridge *br = netdev_priv(dev);
 327
 328         return br_add_if(br, slave_dev);
 329 }
 330
 331 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 332 {
 333         struct net_bridge *br = netdev_priv(dev);
 334
 335         return br_del_if(br, slave_dev);
 336 }
 337
 338 static const struct ethtool_ops br_ethtool_ops = {
 339         .get_drvinfo    = br_getinfo,
 340         .get_link       = ethtool_op_get_link,
 341 };
 342
 343 static const struct net_device_ops br_netdev_ops = {
 344         .ndo_open                = br_dev_open,
 345         .ndo_stop                = br_dev_stop,
 346         .ndo_init                = br_dev_init,
 347         .ndo_uninit              = br_dev_uninit,
 348         .ndo_start_xmit          = br_dev_xmit,
 349         .ndo_get_stats64         = br_get_stats64,
 350         .ndo_set_mac_address     = br_set_mac_address,
 351         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 352         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 353         .ndo_change_mtu          = br_change_mtu,
 354         .ndo_do_ioctl            = br_dev_ioctl,
 355 #ifdef CONFIG_NET_POLL_CONTROLLER
 356         .ndo_netpoll_setup       = br_netpoll_setup,
 357         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 358         .ndo_poll_controller     = br_poll_controller,
 359 #endif
 360         .ndo_add_slave           = br_add_slave,
 361         .ndo_del_slave           = br_del_slave,
 362         .ndo_fix_features        = br_fix_features,
 363         .ndo_fdb_add             = br_fdb_add,
 364         .ndo_fdb_del             = br_fdb_delete,
 365         .ndo_fdb_dump            = br_fdb_dump,
 366         .ndo_bridge_getlink      = br_getlink,
 367         .ndo_bridge_setlink      = br_setlink,
 368         .ndo_bridge_dellink      = br_dellink,
 369         .ndo_features_check      = passthru_features_check,
 370 };
 371
 372 static struct device_type br_type = {
 373         .name   = "bridge",
 374 };
 375
 376 void br_dev_setup(struct net_device *dev)
 377 {
 378         struct net_bridge *br = netdev_priv(dev);
 379
 380         eth_hw_addr_random(dev);
 381         ether_setup(dev);
 382
 383         dev->netdev_ops = &br_netdev_ops;
 384         dev->needs_free_netdev = true;
 385         dev->ethtool_ops = &br_ethtool_ops;
 386         SET_NETDEV_DEVTYPE(dev, &br_type);
 387         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 388
 389         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 390                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 391         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 392                            NETIF_F_HW_VLAN_STAG_TX;
 393         dev->vlan_features = COMMON_FEATURES;
 394
 395         br->dev = dev;
 396         spin_lock_init(&br->lock);
 397         INIT_LIST_HEAD(&br->port_list);
 398         spin_lock_init(&br->hash_lock);
 399
 400         br->bridge_id.prio[0] = 0x80;
 401         br->bridge_id.prio[1] = 0x00;
 402
 403         ether_addr_copy(br->group_addr, eth_reserved_addr_base);
 404
 405         br->stp_enabled = BR_NO_STP;
 406         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 407         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 408
 409         br->designated_root = br->bridge_id;
 410         br->bridge_max_age = br->max_age = 20 * HZ;
 411         br->bridge_hello_time = br->hello_time = 2 * HZ;
 412         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 413         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 414         dev->max_mtu = ETH_MAX_MTU;
 415
 416         br_netfilter_rtable_init(br);
 417         br_stp_timer_init(br);
 418         br_multicast_init(br);
 419         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 420 }