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