net/bridge/br.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      Generic parts
   4  *      Linux ethernet bridge
   5  *
   6  *      Authors:
   7  *      Lennert Buytenhek               <buytenh@gnu.org>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/etherdevice.h>
  14 #include <linux/init.h>
  15 #include <linux/llc.h>
  16 #include <net/llc.h>
  17 #include <net/stp.h>
  18 #include <net/switchdev.h>
  19
  20 #include "br_private.h"
  21
  22 /*
  23  * Handle changes in state of network devices enslaved to a bridge.
  24  *
  25  * Note: don't care about up/down if bridge itself is down, because
  26  *     port state is checked when bridge is brought up.
  27  */
  28 static int br_device_event(struct notifier_block *unused, unsigned long event, void *ptr)
  29 {
  30         struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(ptr);
  31         struct netdev_notifier_pre_changeaddr_info *prechaddr_info;
  32         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
  33         struct net_bridge_port *p;
  34         struct net_bridge *br;
  35         bool notified = false;
  36         bool changed_addr;
  37         int err;
  38
  39         if (netif_is_bridge_master(dev)) {
  40                 err = br_vlan_bridge_event(dev, event, ptr);
  41                 if (err)
  42                         return notifier_from_errno(err);
  43
  44                 if (event == NETDEV_REGISTER) {
  45                         /* register of bridge completed, add sysfs entries */
  46                         err = br_sysfs_addbr(dev);
  47                         if (err)
  48                                 return notifier_from_errno(err);
  49
  50                         return NOTIFY_DONE;
  51                 }
  52         }
  53
  54         if (is_vlan_dev(dev)) {
  55                 struct net_device *real_dev = vlan_dev_real_dev(dev);
  56
  57                 if (netif_is_bridge_master(real_dev))
  58                         br_vlan_vlan_upper_event(real_dev, dev, event);
  59         }
  60
  61         /* not a port of a bridge */
  62         p = br_port_get_rtnl(dev);
  63         if (!p)
  64                 return NOTIFY_DONE;
  65
  66         br = p->br;
  67
  68         switch (event) {
  69         case NETDEV_CHANGEMTU:
  70                 br_mtu_auto_adjust(br);
  71                 break;
  72
  73         case NETDEV_PRE_CHANGEADDR:
  74                 if (br->dev->addr_assign_type == NET_ADDR_SET)
  75                         break;
  76                 prechaddr_info = ptr;
  77                 err = dev_pre_changeaddr_notify(br->dev,
  78                                                 prechaddr_info->dev_addr,
  79                                                 extack);
  80                 if (err)
  81                         return notifier_from_errno(err);
  82                 break;
  83
  84         case NETDEV_CHANGEADDR:
  85                 spin_lock_bh(&br->lock);
  86                 br_fdb_changeaddr(p, dev->dev_addr);
  87                 changed_addr = br_stp_recalculate_bridge_id(br);
  88                 spin_unlock_bh(&br->lock);
  89
  90                 if (changed_addr)
  91                         call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
  92
  93                 break;
  94
  95         case NETDEV_CHANGE:
  96                 br_port_carrier_check(p, &notified);
  97                 break;
  98
  99         case NETDEV_FEAT_CHANGE:
 100                 netdev_update_features(br->dev);
 101                 break;
 102
 103         case NETDEV_DOWN:
 104                 spin_lock_bh(&br->lock);
 105                 if (br->dev->flags & IFF_UP) {
 106                         br_stp_disable_port(p);
 107                         notified = true;
 108                 }
 109                 spin_unlock_bh(&br->lock);
 110                 break;
 111
 112         case NETDEV_UP:
 113                 if (netif_running(br->dev) && netif_oper_up(dev)) {
 114                         spin_lock_bh(&br->lock);
 115                         br_stp_enable_port(p);
 116                         notified = true;
 117                         spin_unlock_bh(&br->lock);
 118                 }
 119                 break;
 120
 121         case NETDEV_UNREGISTER:
 122                 br_del_if(br, dev);
 123                 break;
 124
 125         case NETDEV_CHANGENAME:
 126                 err = br_sysfs_renameif(p);
 127                 if (err)
 128                         return notifier_from_errno(err);
 129                 break;
 130
 131         case NETDEV_PRE_TYPE_CHANGE:
 132                 /* Forbid underlying device to change its type. */
 133                 return NOTIFY_BAD;
 134
 135         case NETDEV_RESEND_IGMP:
 136                 /* Propagate to master device */
 137                 call_netdevice_notifiers(event, br->dev);
 138                 break;
 139         }
 140
 141         if (event != NETDEV_UNREGISTER)
 142                 br_vlan_port_event(p, event);
 143
 144         /* Events that may cause spanning tree to refresh */
 145         if (!notified && (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
 146                           event == NETDEV_CHANGE || event == NETDEV_DOWN))
 147                 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 148
 149         return NOTIFY_DONE;
 150 }
 151
 152 static struct notifier_block br_device_notifier = {
 153         .notifier_call = br_device_event
 154 };
 155
 156 /* called with RTNL or RCU */
 157 static int br_switchdev_event(struct notifier_block *unused,
 158                               unsigned long event, void *ptr)
 159 {
 160         struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
 161         struct net_bridge_port *p;
 162         struct net_bridge *br;
 163         struct switchdev_notifier_fdb_info *fdb_info;
 164         int err = NOTIFY_DONE;
 165
 166         p = br_port_get_rtnl_rcu(dev);
 167         if (!p)
 168                 goto out;
 169
 170         br = p->br;
 171
 172         switch (event) {
 173         case SWITCHDEV_FDB_ADD_TO_BRIDGE:
 174                 fdb_info = ptr;
 175                 err = br_fdb_external_learn_add(br, p, fdb_info->addr,
 176                                                 fdb_info->vid,
 177                                                 fdb_info->locked, false);
 178                 if (err) {
 179                         err = notifier_from_errno(err);
 180                         break;
 181                 }
 182                 br_fdb_offloaded_set(br, p, fdb_info->addr,
 183                                      fdb_info->vid, fdb_info->offloaded);
 184                 break;
 185         case SWITCHDEV_FDB_DEL_TO_BRIDGE:
 186                 fdb_info = ptr;
 187                 err = br_fdb_external_learn_del(br, p, fdb_info->addr,
 188                                                 fdb_info->vid, false);
 189                 if (err)
 190                         err = notifier_from_errno(err);
 191                 break;
 192         case SWITCHDEV_FDB_OFFLOADED:
 193                 fdb_info = ptr;
 194                 br_fdb_offloaded_set(br, p, fdb_info->addr,
 195                                      fdb_info->vid, fdb_info->offloaded);
 196                 break;
 197         case SWITCHDEV_FDB_FLUSH_TO_BRIDGE:
 198                 fdb_info = ptr;
 199                 /* Don't delete static entries */
 200                 br_fdb_delete_by_port(br, p, fdb_info->vid, 0);
 201                 break;
 202         }
 203
 204 out:
 205         return err;
 206 }
 207
 208 static struct notifier_block br_switchdev_notifier = {
 209         .notifier_call = br_switchdev_event,
 210 };
 211
 212 /* called under rtnl_mutex */
 213 static int br_switchdev_blocking_event(struct notifier_block *nb,
 214                                        unsigned long event, void *ptr)
 215 {
 216         struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(ptr);
 217         struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
 218         struct switchdev_notifier_brport_info *brport_info;
 219         const struct switchdev_brport *b;
 220         struct net_bridge_port *p;
 221         int err = NOTIFY_DONE;
 222
 223         p = br_port_get_rtnl(dev);
 224         if (!p)
 225                 goto out;
 226
 227         switch (event) {
 228         case SWITCHDEV_BRPORT_OFFLOADED:
 229                 brport_info = ptr;
 230                 b = &brport_info->brport;
 231
 232                 err = br_switchdev_port_offload(p, b->dev, b->ctx,
 233                                                 b->atomic_nb, b->blocking_nb,
 234                                                 b->tx_fwd_offload, extack);
 235                 err = notifier_from_errno(err);
 236                 break;
 237         case SWITCHDEV_BRPORT_UNOFFLOADED:
 238                 brport_info = ptr;
 239                 b = &brport_info->brport;
 240
 241                 br_switchdev_port_unoffload(p, b->ctx, b->atomic_nb,
 242                                             b->blocking_nb);
 243                 break;
 244         case SWITCHDEV_BRPORT_REPLAY:
 245                 brport_info = ptr;
 246                 b = &brport_info->brport;
 247
 248                 err = br_switchdev_port_replay(p, b->dev, b->ctx, b->atomic_nb,
 249                                                b->blocking_nb, extack);
 250                 err = notifier_from_errno(err);
 251                 break;
 252         }
 253
 254 out:
 255         return err;
 256 }
 257
 258 static struct notifier_block br_switchdev_blocking_notifier = {
 259         .notifier_call = br_switchdev_blocking_event,
 260 };
 261
 262 /* br_boolopt_toggle - change user-controlled boolean option
 263  *
 264  * @br: bridge device
 265  * @opt: id of the option to change
 266  * @on: new option value
 267  * @extack: extack for error messages
 268  *
 269  * Changes the value of the respective boolean option to @on taking care of
 270  * any internal option value mapping and configuration.
 271  */
 272 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
 273                       struct netlink_ext_ack *extack)
 274 {
 275         int err = 0;
 276
 277         switch (opt) {
 278         case BR_BOOLOPT_NO_LL_LEARN:
 279                 br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
 280                 break;
 281         case BR_BOOLOPT_MCAST_VLAN_SNOOPING:
 282                 err = br_multicast_toggle_vlan_snooping(br, on, extack);
 283                 break;
 284         case BR_BOOLOPT_MST_ENABLE:
 285                 err = br_mst_set_enabled(br, on, extack);
 286                 break;
 287         default:
 288                 /* shouldn't be called with unsupported options */
 289                 WARN_ON(1);
 290                 break;
 291         }
 292
 293         return err;
 294 }
 295
 296 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
 297 {
 298         switch (opt) {
 299         case BR_BOOLOPT_NO_LL_LEARN:
 300                 return br_opt_get(br, BROPT_NO_LL_LEARN);
 301         case BR_BOOLOPT_MCAST_VLAN_SNOOPING:
 302                 return br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED);
 303         case BR_BOOLOPT_MST_ENABLE:
 304                 return br_opt_get(br, BROPT_MST_ENABLED);
 305         default:
 306                 /* shouldn't be called with unsupported options */
 307                 WARN_ON(1);
 308                 break;
 309         }
 310
 311         return 0;
 312 }
 313
 314 int br_boolopt_multi_toggle(struct net_bridge *br,
 315                             struct br_boolopt_multi *bm,
 316                             struct netlink_ext_ack *extack)
 317 {
 318         unsigned long bitmap = bm->optmask;
 319         int err = 0;
 320         int opt_id;
 321
 322         for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
 323                 bool on = !!(bm->optval & BIT(opt_id));
 324
 325                 err = br_boolopt_toggle(br, opt_id, on, extack);
 326                 if (err) {
 327                         br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
 328                                  opt_id, br_boolopt_get(br, opt_id), on, err);
 329                         break;
 330                 }
 331         }
 332
 333         return err;
 334 }
 335
 336 void br_boolopt_multi_get(const struct net_bridge *br,
 337                           struct br_boolopt_multi *bm)
 338 {
 339         u32 optval = 0;
 340         int opt_id;
 341
 342         for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
 343                 optval |= (br_boolopt_get(br, opt_id) << opt_id);
 344
 345         bm->optval = optval;
 346         bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
 347 }
 348
 349 /* private bridge options, controlled by the kernel */
 350 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
 351 {
 352         bool cur = !!br_opt_get(br, opt);
 353
 354         br_debug(br, "toggle option: %d state: %d -> %d\n",
 355                  opt, cur, on);
 356
 357         if (cur == on)
 358                 return;
 359
 360         if (on)
 361                 set_bit(opt, &br->options);
 362         else
 363                 clear_bit(opt, &br->options);
 364 }
 365
 366 static void __net_exit br_net_exit_batch_rtnl(struct list_head *net_list,
 367                                               struct list_head *dev_to_kill)
 368 {
 369         struct net_device *dev;
 370         struct net *net;
 371
 372         ASSERT_RTNL();
 373         list_for_each_entry(net, net_list, exit_list)
 374                 for_each_netdev(net, dev)
 375                         if (netif_is_bridge_master(dev))
 376                                 br_dev_delete(dev, dev_to_kill);
 377 }
 378
 379 static struct pernet_operations br_net_ops = {
 380         .exit_batch_rtnl = br_net_exit_batch_rtnl,
 381 };
 382
 383 static const struct stp_proto br_stp_proto = {
 384         .rcv    = br_stp_rcv,
 385 };
 386
 387 static int __init br_init(void)
 388 {
 389         int err;
 390
 391         BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
 392
 393         err = stp_proto_register(&br_stp_proto);
 394         if (err < 0) {
 395                 pr_err("bridge: can't register sap for STP\n");
 396                 return err;
 397         }
 398
 399         err = br_fdb_init();
 400         if (err)
 401                 goto err_out;
 402
 403         err = register_pernet_subsys(&br_net_ops);
 404         if (err)
 405                 goto err_out1;
 406
 407         err = br_nf_core_init();
 408         if (err)
 409                 goto err_out2;
 410
 411         err = register_netdevice_notifier(&br_device_notifier);
 412         if (err)
 413                 goto err_out3;
 414
 415         err = register_switchdev_notifier(&br_switchdev_notifier);
 416         if (err)
 417                 goto err_out4;
 418
 419         err = register_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
 420         if (err)
 421                 goto err_out5;
 422
 423         err = br_netlink_init();
 424         if (err)
 425                 goto err_out6;
 426
 427         brioctl_set(br_ioctl_stub);
 428
 429 #if IS_ENABLED(CONFIG_ATM_LANE)
 430         br_fdb_test_addr_hook = br_fdb_test_addr;
 431 #endif
 432
 433 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
 434         pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
 435                 "by default. Update your scripts to load br_netfilter if you "
 436                 "need this.\n");
 437 #endif
 438
 439         return 0;
 440
 441 err_out6:
 442         unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
 443 err_out5:
 444         unregister_switchdev_notifier(&br_switchdev_notifier);
 445 err_out4:
 446         unregister_netdevice_notifier(&br_device_notifier);
 447 err_out3:
 448         br_nf_core_fini();
 449 err_out2:
 450         unregister_pernet_subsys(&br_net_ops);
 451 err_out1:
 452         br_fdb_fini();
 453 err_out:
 454         stp_proto_unregister(&br_stp_proto);
 455         return err;
 456 }
 457
 458 static void __exit br_deinit(void)
 459 {
 460         stp_proto_unregister(&br_stp_proto);
 461         br_netlink_fini();
 462         unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier);
 463         unregister_switchdev_notifier(&br_switchdev_notifier);
 464         unregister_netdevice_notifier(&br_device_notifier);
 465         brioctl_set(NULL);
 466         unregister_pernet_subsys(&br_net_ops);
 467
 468         rcu_barrier(); /* Wait for completion of call_rcu()'s */
 469
 470         br_nf_core_fini();
 471 #if IS_ENABLED(CONFIG_ATM_LANE)
 472         br_fdb_test_addr_hook = NULL;
 473 #endif
 474         br_fdb_fini();
 475 }
 476
 477 module_init(br_init)
 478 module_exit(br_deinit)
 479 MODULE_LICENSE("GPL");
 480 MODULE_VERSION(BR_VERSION);
 481 MODULE_ALIAS_RTNL_LINK("bridge");
 482 MODULE_DESCRIPTION("Ethernet bridge driver");