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                         br_sysfs_addbr(dev);
  47                         return NOTIFY_DONE;
  48                 }
  49         }
  50
  51         /* not a port of a bridge */
  52         p = br_port_get_rtnl(dev);
  53         if (!p)
  54                 return NOTIFY_DONE;
  55
  56         br = p->br;
  57
  58         switch (event) {
  59         case NETDEV_CHANGEMTU:
  60                 br_mtu_auto_adjust(br);
  61                 break;
  62
  63         case NETDEV_PRE_CHANGEADDR:
  64                 if (br->dev->addr_assign_type == NET_ADDR_SET)
  65                         break;
  66                 prechaddr_info = ptr;
  67                 err = dev_pre_changeaddr_notify(br->dev,
  68                                                 prechaddr_info->dev_addr,
  69                                                 extack);
  70                 if (err)
  71                         return notifier_from_errno(err);
  72                 break;
  73
  74         case NETDEV_CHANGEADDR:
  75                 spin_lock_bh(&br->lock);
  76                 br_fdb_changeaddr(p, dev->dev_addr);
  77                 changed_addr = br_stp_recalculate_bridge_id(br);
  78                 spin_unlock_bh(&br->lock);
  79
  80                 if (changed_addr)
  81                         call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
  82
  83                 break;
  84
  85         case NETDEV_CHANGE:
  86                 br_port_carrier_check(p, &notified);
  87                 break;
  88
  89         case NETDEV_FEAT_CHANGE:
  90                 netdev_update_features(br->dev);
  91                 break;
  92
  93         case NETDEV_DOWN:
  94                 spin_lock_bh(&br->lock);
  95                 if (br->dev->flags & IFF_UP) {
  96                         br_stp_disable_port(p);
  97                         notified = true;
  98                 }
  99                 spin_unlock_bh(&br->lock);
 100                 break;
 101
 102         case NETDEV_UP:
 103                 if (netif_running(br->dev) && netif_oper_up(dev)) {
 104                         spin_lock_bh(&br->lock);
 105                         br_stp_enable_port(p);
 106                         notified = true;
 107                         spin_unlock_bh(&br->lock);
 108                 }
 109                 break;
 110
 111         case NETDEV_UNREGISTER:
 112                 br_del_if(br, dev);
 113                 break;
 114
 115         case NETDEV_CHANGENAME:
 116                 err = br_sysfs_renameif(p);
 117                 if (err)
 118                         return notifier_from_errno(err);
 119                 break;
 120
 121         case NETDEV_PRE_TYPE_CHANGE:
 122                 /* Forbid underlaying device to change its type. */
 123                 return NOTIFY_BAD;
 124
 125         case NETDEV_RESEND_IGMP:
 126                 /* Propagate to master device */
 127                 call_netdevice_notifiers(event, br->dev);
 128                 break;
 129         }
 130
 131         if (event != NETDEV_UNREGISTER)
 132                 br_vlan_port_event(p, event);
 133
 134         /* Events that may cause spanning tree to refresh */
 135         if (!notified && (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
 136                           event == NETDEV_CHANGE || event == NETDEV_DOWN))
 137                 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 138
 139         return NOTIFY_DONE;
 140 }
 141
 142 static struct notifier_block br_device_notifier = {
 143         .notifier_call = br_device_event
 144 };
 145
 146 /* called with RTNL or RCU */
 147 static int br_switchdev_event(struct notifier_block *unused,
 148                               unsigned long event, void *ptr)
 149 {
 150         struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
 151         struct net_bridge_port *p;
 152         struct net_bridge *br;
 153         struct switchdev_notifier_fdb_info *fdb_info;
 154         int err = NOTIFY_DONE;
 155
 156         p = br_port_get_rtnl_rcu(dev);
 157         if (!p)
 158                 goto out;
 159
 160         br = p->br;
 161
 162         switch (event) {
 163         case SWITCHDEV_FDB_ADD_TO_BRIDGE:
 164                 fdb_info = ptr;
 165                 err = br_fdb_external_learn_add(br, p, fdb_info->addr,
 166                                                 fdb_info->vid, false);
 167                 if (err) {
 168                         err = notifier_from_errno(err);
 169                         break;
 170                 }
 171                 br_fdb_offloaded_set(br, p, fdb_info->addr,
 172                                      fdb_info->vid, true);
 173                 break;
 174         case SWITCHDEV_FDB_DEL_TO_BRIDGE:
 175                 fdb_info = ptr;
 176                 err = br_fdb_external_learn_del(br, p, fdb_info->addr,
 177                                                 fdb_info->vid, false);
 178                 if (err)
 179                         err = notifier_from_errno(err);
 180                 break;
 181         case SWITCHDEV_FDB_OFFLOADED:
 182                 fdb_info = ptr;
 183                 br_fdb_offloaded_set(br, p, fdb_info->addr,
 184                                      fdb_info->vid, fdb_info->offloaded);
 185                 break;
 186         }
 187
 188 out:
 189         return err;
 190 }
 191
 192 static struct notifier_block br_switchdev_notifier = {
 193         .notifier_call = br_switchdev_event,
 194 };
 195
 196 /* br_boolopt_toggle - change user-controlled boolean option
 197  *
 198  * @br: bridge device
 199  * @opt: id of the option to change
 200  * @on: new option value
 201  * @extack: extack for error messages
 202  *
 203  * Changes the value of the respective boolean option to @on taking care of
 204  * any internal option value mapping and configuration.
 205  */
 206 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
 207                       struct netlink_ext_ack *extack)
 208 {
 209         switch (opt) {
 210         case BR_BOOLOPT_NO_LL_LEARN:
 211                 br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
 212                 break;
 213         default:
 214                 /* shouldn't be called with unsupported options */
 215                 WARN_ON(1);
 216                 break;
 217         }
 218
 219         return 0;
 220 }
 221
 222 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
 223 {
 224         switch (opt) {
 225         case BR_BOOLOPT_NO_LL_LEARN:
 226                 return br_opt_get(br, BROPT_NO_LL_LEARN);
 227         default:
 228                 /* shouldn't be called with unsupported options */
 229                 WARN_ON(1);
 230                 break;
 231         }
 232
 233         return 0;
 234 }
 235
 236 int br_boolopt_multi_toggle(struct net_bridge *br,
 237                             struct br_boolopt_multi *bm,
 238                             struct netlink_ext_ack *extack)
 239 {
 240         unsigned long bitmap = bm->optmask;
 241         int err = 0;
 242         int opt_id;
 243
 244         for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
 245                 bool on = !!(bm->optval & BIT(opt_id));
 246
 247                 err = br_boolopt_toggle(br, opt_id, on, extack);
 248                 if (err) {
 249                         br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
 250                                  opt_id, br_boolopt_get(br, opt_id), on, err);
 251                         break;
 252                 }
 253         }
 254
 255         return err;
 256 }
 257
 258 void br_boolopt_multi_get(const struct net_bridge *br,
 259                           struct br_boolopt_multi *bm)
 260 {
 261         u32 optval = 0;
 262         int opt_id;
 263
 264         for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
 265                 optval |= (br_boolopt_get(br, opt_id) << opt_id);
 266
 267         bm->optval = optval;
 268         bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
 269 }
 270
 271 /* private bridge options, controlled by the kernel */
 272 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
 273 {
 274         bool cur = !!br_opt_get(br, opt);
 275
 276         br_debug(br, "toggle option: %d state: %d -> %d\n",
 277                  opt, cur, on);
 278
 279         if (cur == on)
 280                 return;
 281
 282         if (on)
 283                 set_bit(opt, &br->options);
 284         else
 285                 clear_bit(opt, &br->options);
 286 }
 287
 288 static void __net_exit br_net_exit(struct net *net)
 289 {
 290         struct net_device *dev;
 291         LIST_HEAD(list);
 292
 293         rtnl_lock();
 294         for_each_netdev(net, dev)
 295                 if (dev->priv_flags & IFF_EBRIDGE)
 296                         br_dev_delete(dev, &list);
 297
 298         unregister_netdevice_many(&list);
 299         rtnl_unlock();
 300
 301 }
 302
 303 static struct pernet_operations br_net_ops = {
 304         .exit   = br_net_exit,
 305 };
 306
 307 static const struct stp_proto br_stp_proto = {
 308         .rcv    = br_stp_rcv,
 309 };
 310
 311 static int __init br_init(void)
 312 {
 313         int err;
 314
 315         BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb));
 316
 317         err = stp_proto_register(&br_stp_proto);
 318         if (err < 0) {
 319                 pr_err("bridge: can't register sap for STP\n");
 320                 return err;
 321         }
 322
 323         err = br_fdb_init();
 324         if (err)
 325                 goto err_out;
 326
 327         err = register_pernet_subsys(&br_net_ops);
 328         if (err)
 329                 goto err_out1;
 330
 331         err = br_nf_core_init();
 332         if (err)
 333                 goto err_out2;
 334
 335         err = register_netdevice_notifier(&br_device_notifier);
 336         if (err)
 337                 goto err_out3;
 338
 339         err = register_switchdev_notifier(&br_switchdev_notifier);
 340         if (err)
 341                 goto err_out4;
 342
 343         err = br_netlink_init();
 344         if (err)
 345                 goto err_out5;
 346
 347         brioctl_set(br_ioctl_deviceless_stub);
 348
 349 #if IS_ENABLED(CONFIG_ATM_LANE)
 350         br_fdb_test_addr_hook = br_fdb_test_addr;
 351 #endif
 352
 353 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
 354         pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
 355                 "by default. Update your scripts to load br_netfilter if you "
 356                 "need this.\n");
 357 #endif
 358
 359         return 0;
 360
 361 err_out5:
 362         unregister_switchdev_notifier(&br_switchdev_notifier);
 363 err_out4:
 364         unregister_netdevice_notifier(&br_device_notifier);
 365 err_out3:
 366         br_nf_core_fini();
 367 err_out2:
 368         unregister_pernet_subsys(&br_net_ops);
 369 err_out1:
 370         br_fdb_fini();
 371 err_out:
 372         stp_proto_unregister(&br_stp_proto);
 373         return err;
 374 }
 375
 376 static void __exit br_deinit(void)
 377 {
 378         stp_proto_unregister(&br_stp_proto);
 379         br_netlink_fini();
 380         unregister_switchdev_notifier(&br_switchdev_notifier);
 381         unregister_netdevice_notifier(&br_device_notifier);
 382         brioctl_set(NULL);
 383         unregister_pernet_subsys(&br_net_ops);
 384
 385         rcu_barrier(); /* Wait for completion of call_rcu()'s */
 386
 387         br_nf_core_fini();
 388 #if IS_ENABLED(CONFIG_ATM_LANE)
 389         br_fdb_test_addr_hook = NULL;
 390 #endif
 391         br_fdb_fini();
 392 }
 393
 394 module_init(br_init)
 395 module_exit(br_deinit)
 396 MODULE_LICENSE("GPL");
 397 MODULE_VERSION(BR_VERSION);
 398 MODULE_ALIAS_RTNL_LINK("bridge");