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 /* br_boolopt_toggle - change user-controlled boolean option
 206  *
 207  * @br: bridge device
 208  * @opt: id of the option to change
 209  * @on: new option value
 210  * @extack: extack for error messages
 211  *
 212  * Changes the value of the respective boolean option to @on taking care of
 213  * any internal option value mapping and configuration.
 214  */
 215 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
 216                       struct netlink_ext_ack *extack)
 217 {
 218         switch (opt) {
 219         case BR_BOOLOPT_NO_LL_LEARN:
 220                 br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
 221                 break;
 222         default:
 223                 /* shouldn't be called with unsupported options */
 224                 WARN_ON(1);
 225                 break;
 226         }
 227
 228         return 0;
 229 }
 230
 231 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
 232 {
 233         switch (opt) {
 234         case BR_BOOLOPT_NO_LL_LEARN:
 235                 return br_opt_get(br, BROPT_NO_LL_LEARN);
 236         default:
 237                 /* shouldn't be called with unsupported options */
 238                 WARN_ON(1);
 239                 break;
 240         }
 241
 242         return 0;
 243 }
 244
 245 int br_boolopt_multi_toggle(struct net_bridge *br,
 246                             struct br_boolopt_multi *bm,
 247                             struct netlink_ext_ack *extack)
 248 {
 249         unsigned long bitmap = bm->optmask;
 250         int err = 0;
 251         int opt_id;
 252
 253         for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
 254                 bool on = !!(bm->optval & BIT(opt_id));
 255
 256                 err = br_boolopt_toggle(br, opt_id, on, extack);
 257                 if (err) {
 258                         br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
 259                                  opt_id, br_boolopt_get(br, opt_id), on, err);
 260                         break;
 261                 }
 262         }
 263
 264         return err;
 265 }
 266
 267 void br_boolopt_multi_get(const struct net_bridge *br,
 268                           struct br_boolopt_multi *bm)
 269 {
 270         u32 optval = 0;
 271         int opt_id;
 272
 273         for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
 274                 optval |= (br_boolopt_get(br, opt_id) << opt_id);
 275
 276         bm->optval = optval;
 277         bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
 278 }
 279
 280 /* private bridge options, controlled by the kernel */
 281 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
 282 {
 283         bool cur = !!br_opt_get(br, opt);
 284
 285         br_debug(br, "toggle option: %d state: %d -> %d\n",
 286                  opt, cur, on);
 287
 288         if (cur == on)
 289                 return;
 290
 291         if (on)
 292                 set_bit(opt, &br->options);
 293         else
 294                 clear_bit(opt, &br->options);
 295 }
 296
 297 static void __net_exit br_net_exit(struct net *net)
 298 {
 299         struct net_device *dev;
 300         LIST_HEAD(list);
 301
 302         rtnl_lock();
 303         for_each_netdev(net, dev)
 304                 if (dev->priv_flags & IFF_EBRIDGE)
 305                         br_dev_delete(dev, &list);
 306
 307         unregister_netdevice_many(&list);
 308         rtnl_unlock();
 309
 310 }
 311
 312 static struct pernet_operations br_net_ops = {
 313         .exit   = br_net_exit,
 314 };
 315
 316 static const struct stp_proto br_stp_proto = {
 317         .rcv    = br_stp_rcv,
 318 };
 319
 320 static int __init br_init(void)
 321 {
 322         int err;
 323
 324         BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
 325
 326         err = stp_proto_register(&br_stp_proto);
 327         if (err < 0) {
 328                 pr_err("bridge: can't register sap for STP\n");
 329                 return err;
 330         }
 331
 332         err = br_fdb_init();
 333         if (err)
 334                 goto err_out;
 335
 336         err = register_pernet_subsys(&br_net_ops);
 337         if (err)
 338                 goto err_out1;
 339
 340         err = br_nf_core_init();
 341         if (err)
 342                 goto err_out2;
 343
 344         err = register_netdevice_notifier(&br_device_notifier);
 345         if (err)
 346                 goto err_out3;
 347
 348         err = register_switchdev_notifier(&br_switchdev_notifier);
 349         if (err)
 350                 goto err_out4;
 351
 352         err = br_netlink_init();
 353         if (err)
 354                 goto err_out5;
 355
 356         brioctl_set(br_ioctl_deviceless_stub);
 357
 358 #if IS_ENABLED(CONFIG_ATM_LANE)
 359         br_fdb_test_addr_hook = br_fdb_test_addr;
 360 #endif
 361
 362 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
 363         pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
 364                 "by default. Update your scripts to load br_netfilter if you "
 365                 "need this.\n");
 366 #endif
 367
 368         return 0;
 369
 370 err_out5:
 371         unregister_switchdev_notifier(&br_switchdev_notifier);
 372 err_out4:
 373         unregister_netdevice_notifier(&br_device_notifier);
 374 err_out3:
 375         br_nf_core_fini();
 376 err_out2:
 377         unregister_pernet_subsys(&br_net_ops);
 378 err_out1:
 379         br_fdb_fini();
 380 err_out:
 381         stp_proto_unregister(&br_stp_proto);
 382         return err;
 383 }
 384
 385 static void __exit br_deinit(void)
 386 {
 387         stp_proto_unregister(&br_stp_proto);
 388         br_netlink_fini();
 389         unregister_switchdev_notifier(&br_switchdev_notifier);
 390         unregister_netdevice_notifier(&br_device_notifier);
 391         brioctl_set(NULL);
 392         unregister_pernet_subsys(&br_net_ops);
 393
 394         rcu_barrier(); /* Wait for completion of call_rcu()'s */
 395
 396         br_nf_core_fini();
 397 #if IS_ENABLED(CONFIG_ATM_LANE)
 398         br_fdb_test_addr_hook = NULL;
 399 #endif
 400         br_fdb_fini();
 401 }
 402
 403 module_init(br_init)
 404 module_exit(br_deinit)
 405 MODULE_LICENSE("GPL");
 406 MODULE_VERSION(BR_VERSION);
 407 MODULE_ALIAS_RTNL_LINK("bridge");