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         struct ethhdr *eth;
  43         u16 vid = 0;
  44
  45         rcu_read_lock();
  46         nf_ops = rcu_dereference(nf_br_ops);
  47         if (nf_ops && nf_ops->br_dev_xmit_hook(skb)) {
  48                 rcu_read_unlock();
  49                 return NETDEV_TX_OK;
  50         }
  51
  52         u64_stats_update_begin(&brstats->syncp);
  53         brstats->tx_packets++;
  54         brstats->tx_bytes += skb->len;
  55         u64_stats_update_end(&brstats->syncp);
  56
  57         br_switchdev_frame_unmark(skb);
  58         BR_INPUT_SKB_CB(skb)->brdev = dev;
  59
  60         skb_reset_mac_header(skb);
  61         eth = eth_hdr(skb);
  62         skb_pull(skb, ETH_HLEN);
  63
  64         if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid))
  65                 goto out;
  66
  67         if (IS_ENABLED(CONFIG_INET) &&
  68             (eth->h_proto == htons(ETH_P_ARP) ||
  69              eth->h_proto == htons(ETH_P_RARP)) &&
  70             br->neigh_suppress_enabled) {
  71                 br_do_proxy_suppress_arp(skb, br, vid, NULL);
  72         } else if (IS_ENABLED(CONFIG_IPV6) &&
  73                    skb->protocol == htons(ETH_P_IPV6) &&
  74                    br->neigh_suppress_enabled &&
  75                    pskb_may_pull(skb, sizeof(struct ipv6hdr) +
  76                                  sizeof(struct nd_msg)) &&
  77                    ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) {
  78                         struct nd_msg *msg, _msg;
  79
  80                         msg = br_is_nd_neigh_msg(skb, &_msg);
  81                         if (msg)
  82                                 br_do_suppress_nd(skb, br, vid, NULL, msg);
  83         }
  84
  85         dest = eth_hdr(skb)->h_dest;
  86         if (is_broadcast_ether_addr(dest)) {
  87                 br_flood(br, skb, BR_PKT_BROADCAST, false, true);
  88         } else if (is_multicast_ether_addr(dest)) {
  89                 if (unlikely(netpoll_tx_running(dev))) {
  90                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
  91                         goto out;
  92                 }
  93                 if (br_multicast_rcv(br, NULL, skb, vid)) {
  94                         kfree_skb(skb);
  95                         goto out;
  96                 }
  97
  98                 mdst = br_mdb_get(br, skb, vid);
  99                 if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
 100                     br_multicast_querier_exists(br, eth_hdr(skb)))
 101                         br_multicast_flood(mdst, skb, false, true);
 102                 else
 103                         br_flood(br, skb, BR_PKT_MULTICAST, false, true);
 104         } else if ((dst = br_fdb_find_rcu(br, dest, vid)) != NULL) {
 105                 br_forward(dst->dst, skb, false, true);
 106         } else {
 107                 br_flood(br, skb, BR_PKT_UNICAST, false, true);
 108         }
 109 out:
 110         rcu_read_unlock();
 111         return NETDEV_TX_OK;
 112 }
 113
 114 static void br_set_lockdep_class(struct net_device *dev)
 115 {
 116         lockdep_set_class(&dev->addr_list_lock, &bridge_netdev_addr_lock_key);
 117 }
 118
 119 static int br_dev_init(struct net_device *dev)
 120 {
 121         struct net_bridge *br = netdev_priv(dev);
 122         int err;
 123
 124         br->stats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
 125         if (!br->stats)
 126                 return -ENOMEM;
 127
 128         err = br_vlan_init(br);
 129         if (err) {
 130                 free_percpu(br->stats);
 131                 return err;
 132         }
 133
 134         err = br_multicast_init_stats(br);
 135         if (err) {
 136                 free_percpu(br->stats);
 137                 br_vlan_flush(br);
 138         }
 139         br_set_lockdep_class(dev);
 140
 141         return err;
 142 }
 143
 144 static void br_dev_uninit(struct net_device *dev)
 145 {
 146         struct net_bridge *br = netdev_priv(dev);
 147
 148         br_multicast_dev_del(br);
 149         br_multicast_uninit_stats(br);
 150         br_vlan_flush(br);
 151         free_percpu(br->stats);
 152 }
 153
 154 static int br_dev_open(struct net_device *dev)
 155 {
 156         struct net_bridge *br = netdev_priv(dev);
 157
 158         netdev_update_features(dev);
 159         netif_start_queue(dev);
 160         br_stp_enable_bridge(br);
 161         br_multicast_open(br);
 162
 163         return 0;
 164 }
 165
 166 static void br_dev_set_multicast_list(struct net_device *dev)
 167 {
 168 }
 169
 170 static void br_dev_change_rx_flags(struct net_device *dev, int change)
 171 {
 172         if (change & IFF_PROMISC)
 173                 br_manage_promisc(netdev_priv(dev));
 174 }
 175
 176 static int br_dev_stop(struct net_device *dev)
 177 {
 178         struct net_bridge *br = netdev_priv(dev);
 179
 180         br_stp_disable_bridge(br);
 181         br_multicast_stop(br);
 182
 183         netif_stop_queue(dev);
 184
 185         return 0;
 186 }
 187
 188 static void br_get_stats64(struct net_device *dev,
 189                            struct rtnl_link_stats64 *stats)
 190 {
 191         struct net_bridge *br = netdev_priv(dev);
 192         struct pcpu_sw_netstats tmp, sum = { 0 };
 193         unsigned int cpu;
 194
 195         for_each_possible_cpu(cpu) {
 196                 unsigned int start;
 197                 const struct pcpu_sw_netstats *bstats
 198                         = per_cpu_ptr(br->stats, cpu);
 199                 do {
 200                         start = u64_stats_fetch_begin_irq(&bstats->syncp);
 201                         memcpy(&tmp, bstats, sizeof(tmp));
 202                 } while (u64_stats_fetch_retry_irq(&bstats->syncp, start));
 203                 sum.tx_bytes   += tmp.tx_bytes;
 204                 sum.tx_packets += tmp.tx_packets;
 205                 sum.rx_bytes   += tmp.rx_bytes;
 206                 sum.rx_packets += tmp.rx_packets;
 207         }
 208
 209         stats->tx_bytes   = sum.tx_bytes;
 210         stats->tx_packets = sum.tx_packets;
 211         stats->rx_bytes   = sum.rx_bytes;
 212         stats->rx_packets = sum.rx_packets;
 213 }
 214
 215 static int br_change_mtu(struct net_device *dev, int new_mtu)
 216 {
 217         struct net_bridge *br = netdev_priv(dev);
 218         if (new_mtu > br_min_mtu(br))
 219                 return -EINVAL;
 220
 221         dev->mtu = new_mtu;
 222
 223 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
 224         /* remember the MTU in the rtable for PMTU */
 225         dst_metric_set(&br->fake_rtable.dst, RTAX_MTU, new_mtu);
 226 #endif
 227
 228         return 0;
 229 }
 230
 231 /* Allow setting mac address to any valid ethernet address. */
 232 static int br_set_mac_address(struct net_device *dev, void *p)
 233 {
 234         struct net_bridge *br = netdev_priv(dev);
 235         struct sockaddr *addr = p;
 236
 237         if (!is_valid_ether_addr(addr->sa_data))
 238                 return -EADDRNOTAVAIL;
 239
 240         spin_lock_bh(&br->lock);
 241         if (!ether_addr_equal(dev->dev_addr, addr->sa_data)) {
 242                 /* Mac address will be changed in br_stp_change_bridge_id(). */
 243                 br_stp_change_bridge_id(br, addr->sa_data);
 244         }
 245         spin_unlock_bh(&br->lock);
 246
 247         return 0;
 248 }
 249
 250 static void br_getinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 251 {
 252         strlcpy(info->driver, "bridge", sizeof(info->driver));
 253         strlcpy(info->version, BR_VERSION, sizeof(info->version));
 254         strlcpy(info->fw_version, "N/A", sizeof(info->fw_version));
 255         strlcpy(info->bus_info, "N/A", sizeof(info->bus_info));
 256 }
 257
 258 static netdev_features_t br_fix_features(struct net_device *dev,
 259         netdev_features_t features)
 260 {
 261         struct net_bridge *br = netdev_priv(dev);
 262
 263         return br_features_recompute(br, features);
 264 }
 265
 266 #ifdef CONFIG_NET_POLL_CONTROLLER
 267 static void br_poll_controller(struct net_device *br_dev)
 268 {
 269 }
 270
 271 static void br_netpoll_cleanup(struct net_device *dev)
 272 {
 273         struct net_bridge *br = netdev_priv(dev);
 274         struct net_bridge_port *p;
 275
 276         list_for_each_entry(p, &br->port_list, list)
 277                 br_netpoll_disable(p);
 278 }
 279
 280 static int __br_netpoll_enable(struct net_bridge_port *p)
 281 {
 282         struct netpoll *np;
 283         int err;
 284
 285         np = kzalloc(sizeof(*p->np), GFP_KERNEL);
 286         if (!np)
 287                 return -ENOMEM;
 288
 289         err = __netpoll_setup(np, p->dev);
 290         if (err) {
 291                 kfree(np);
 292                 return err;
 293         }
 294
 295         p->np = np;
 296         return err;
 297 }
 298
 299 int br_netpoll_enable(struct net_bridge_port *p)
 300 {
 301         if (!p->br->dev->npinfo)
 302                 return 0;
 303
 304         return __br_netpoll_enable(p);
 305 }
 306
 307 static int br_netpoll_setup(struct net_device *dev, struct netpoll_info *ni)
 308 {
 309         struct net_bridge *br = netdev_priv(dev);
 310         struct net_bridge_port *p;
 311         int err = 0;
 312
 313         list_for_each_entry(p, &br->port_list, list) {
 314                 if (!p->dev)
 315                         continue;
 316                 err = __br_netpoll_enable(p);
 317                 if (err)
 318                         goto fail;
 319         }
 320
 321 out:
 322         return err;
 323
 324 fail:
 325         br_netpoll_cleanup(dev);
 326         goto out;
 327 }
 328
 329 void br_netpoll_disable(struct net_bridge_port *p)
 330 {
 331         struct netpoll *np = p->np;
 332
 333         if (!np)
 334                 return;
 335
 336         p->np = NULL;
 337
 338         __netpoll_free_async(np);
 339 }
 340
 341 #endif
 342
 343 static int br_add_slave(struct net_device *dev, struct net_device *slave_dev,
 344                         struct netlink_ext_ack *extack)
 345
 346 {
 347         struct net_bridge *br = netdev_priv(dev);
 348
 349         return br_add_if(br, slave_dev, extack);
 350 }
 351
 352 static int br_del_slave(struct net_device *dev, struct net_device *slave_dev)
 353 {
 354         struct net_bridge *br = netdev_priv(dev);
 355
 356         return br_del_if(br, slave_dev);
 357 }
 358
 359 static const struct ethtool_ops br_ethtool_ops = {
 360         .get_drvinfo    = br_getinfo,
 361         .get_link       = ethtool_op_get_link,
 362 };
 363
 364 static const struct net_device_ops br_netdev_ops = {
 365         .ndo_open                = br_dev_open,
 366         .ndo_stop                = br_dev_stop,
 367         .ndo_init                = br_dev_init,
 368         .ndo_uninit              = br_dev_uninit,
 369         .ndo_start_xmit          = br_dev_xmit,
 370         .ndo_get_stats64         = br_get_stats64,
 371         .ndo_set_mac_address     = br_set_mac_address,
 372         .ndo_set_rx_mode         = br_dev_set_multicast_list,
 373         .ndo_change_rx_flags     = br_dev_change_rx_flags,
 374         .ndo_change_mtu          = br_change_mtu,
 375         .ndo_do_ioctl            = br_dev_ioctl,
 376 #ifdef CONFIG_NET_POLL_CONTROLLER
 377         .ndo_netpoll_setup       = br_netpoll_setup,
 378         .ndo_netpoll_cleanup     = br_netpoll_cleanup,
 379         .ndo_poll_controller     = br_poll_controller,
 380 #endif
 381         .ndo_add_slave           = br_add_slave,
 382         .ndo_del_slave           = br_del_slave,
 383         .ndo_fix_features        = br_fix_features,
 384         .ndo_fdb_add             = br_fdb_add,
 385         .ndo_fdb_del             = br_fdb_delete,
 386         .ndo_fdb_dump            = br_fdb_dump,
 387         .ndo_bridge_getlink      = br_getlink,
 388         .ndo_bridge_setlink      = br_setlink,
 389         .ndo_bridge_dellink      = br_dellink,
 390         .ndo_features_check      = passthru_features_check,
 391 };
 392
 393 static struct device_type br_type = {
 394         .name   = "bridge",
 395 };
 396
 397 void br_dev_setup(struct net_device *dev)
 398 {
 399         struct net_bridge *br = netdev_priv(dev);
 400
 401         eth_hw_addr_random(dev);
 402         ether_setup(dev);
 403
 404         dev->netdev_ops = &br_netdev_ops;
 405         dev->needs_free_netdev = true;
 406         dev->ethtool_ops = &br_ethtool_ops;
 407         SET_NETDEV_DEVTYPE(dev, &br_type);
 408         dev->priv_flags = IFF_EBRIDGE | IFF_NO_QUEUE;
 409
 410         dev->features = COMMON_FEATURES | NETIF_F_LLTX | NETIF_F_NETNS_LOCAL |
 411                         NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX;
 412         dev->hw_features = COMMON_FEATURES | NETIF_F_HW_VLAN_CTAG_TX |
 413                            NETIF_F_HW_VLAN_STAG_TX;
 414         dev->vlan_features = COMMON_FEATURES;
 415
 416         br->dev = dev;
 417         spin_lock_init(&br->lock);
 418         INIT_LIST_HEAD(&br->port_list);
 419         spin_lock_init(&br->hash_lock);
 420
 421         br->bridge_id.prio[0] = 0x80;
 422         br->bridge_id.prio[1] = 0x00;
 423
 424         ether_addr_copy(br->group_addr, eth_stp_addr);
 425
 426         br->stp_enabled = BR_NO_STP;
 427         br->group_fwd_mask = BR_GROUPFWD_DEFAULT;
 428         br->group_fwd_mask_required = BR_GROUPFWD_DEFAULT;
 429
 430         br->designated_root = br->bridge_id;
 431         br->bridge_max_age = br->max_age = 20 * HZ;
 432         br->bridge_hello_time = br->hello_time = 2 * HZ;
 433         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 434         br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
 435         dev->max_mtu = ETH_MAX_MTU;
 436
 437         br_netfilter_rtable_init(br);
 438         br_stp_timer_init(br);
 439         br_multicast_init(br);
 440         INIT_DELAYED_WORK(&br->gc_work, br_fdb_cleanup);
 441 }