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                 if (event == NETDEV_REGISTER) {
  41                         /* register of bridge completed, add sysfs entries */
  42                         br_sysfs_addbr(dev);
  43                         return NOTIFY_DONE;
  44                 }
  45                 br_vlan_bridge_event(dev, event, ptr);
  46         }
  47
  48         /* not a port of a bridge */
  49         p = br_port_get_rtnl(dev);
  50         if (!p)
  51                 return NOTIFY_DONE;
  52
  53         br = p->br;
  54
  55         switch (event) {
  56         case NETDEV_CHANGEMTU:
  57                 br_mtu_auto_adjust(br);
  58                 break;
  59
  60         case NETDEV_PRE_CHANGEADDR:
  61                 if (br->dev->addr_assign_type == NET_ADDR_SET)
  62                         break;
  63                 prechaddr_info = ptr;
  64                 err = dev_pre_changeaddr_notify(br->dev,
  65                                                 prechaddr_info->dev_addr,
  66                                                 extack);
  67                 if (err)
  68                         return notifier_from_errno(err);
  69                 break;
  70
  71         case NETDEV_CHANGEADDR:
  72                 spin_lock_bh(&br->lock);
  73                 br_fdb_changeaddr(p, dev->dev_addr);
  74                 changed_addr = br_stp_recalculate_bridge_id(br);
  75                 spin_unlock_bh(&br->lock);
  76
  77                 if (changed_addr)
  78                         call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev);
  79
  80                 break;
  81
  82         case NETDEV_CHANGE:
  83                 br_port_carrier_check(p, &notified);
  84                 break;
  85
  86         case NETDEV_FEAT_CHANGE:
  87                 netdev_update_features(br->dev);
  88                 break;
  89
  90         case NETDEV_DOWN:
  91                 spin_lock_bh(&br->lock);
  92                 if (br->dev->flags & IFF_UP) {
  93                         br_stp_disable_port(p);
  94                         notified = true;
  95                 }
  96                 spin_unlock_bh(&br->lock);
  97                 break;
  98
  99         case NETDEV_UP:
 100                 if (netif_running(br->dev) && netif_oper_up(dev)) {
 101                         spin_lock_bh(&br->lock);
 102                         br_stp_enable_port(p);
 103                         notified = true;
 104                         spin_unlock_bh(&br->lock);
 105                 }
 106                 break;
 107
 108         case NETDEV_UNREGISTER:
 109                 br_del_if(br, dev);
 110                 break;
 111
 112         case NETDEV_CHANGENAME:
 113                 err = br_sysfs_renameif(p);
 114                 if (err)
 115                         return notifier_from_errno(err);
 116                 break;
 117
 118         case NETDEV_PRE_TYPE_CHANGE:
 119                 /* Forbid underlaying device to change its type. */
 120                 return NOTIFY_BAD;
 121
 122         case NETDEV_RESEND_IGMP:
 123                 /* Propagate to master device */
 124                 call_netdevice_notifiers(event, br->dev);
 125                 break;
 126         }
 127
 128         if (event != NETDEV_UNREGISTER)
 129                 br_vlan_port_event(p, event);
 130
 131         /* Events that may cause spanning tree to refresh */
 132         if (!notified && (event == NETDEV_CHANGEADDR || event == NETDEV_UP ||
 133                           event == NETDEV_CHANGE || event == NETDEV_DOWN))
 134                 br_ifinfo_notify(RTM_NEWLINK, NULL, p);
 135
 136         return NOTIFY_DONE;
 137 }
 138
 139 static struct notifier_block br_device_notifier = {
 140         .notifier_call = br_device_event
 141 };
 142
 143 /* called with RTNL or RCU */
 144 static int br_switchdev_event(struct notifier_block *unused,
 145                               unsigned long event, void *ptr)
 146 {
 147         struct net_device *dev = switchdev_notifier_info_to_dev(ptr);
 148         struct net_bridge_port *p;
 149         struct net_bridge *br;
 150         struct switchdev_notifier_fdb_info *fdb_info;
 151         int err = NOTIFY_DONE;
 152
 153         p = br_port_get_rtnl_rcu(dev);
 154         if (!p)
 155                 goto out;
 156
 157         br = p->br;
 158
 159         switch (event) {
 160         case SWITCHDEV_FDB_ADD_TO_BRIDGE:
 161                 fdb_info = ptr;
 162                 err = br_fdb_external_learn_add(br, p, fdb_info->addr,
 163                                                 fdb_info->vid, false);
 164                 if (err) {
 165                         err = notifier_from_errno(err);
 166                         break;
 167                 }
 168                 br_fdb_offloaded_set(br, p, fdb_info->addr,
 169                                      fdb_info->vid, true);
 170                 break;
 171         case SWITCHDEV_FDB_DEL_TO_BRIDGE:
 172                 fdb_info = ptr;
 173                 err = br_fdb_external_learn_del(br, p, fdb_info->addr,
 174                                                 fdb_info->vid, false);
 175                 if (err)
 176                         err = notifier_from_errno(err);
 177                 break;
 178         case SWITCHDEV_FDB_OFFLOADED:
 179                 fdb_info = ptr;
 180                 br_fdb_offloaded_set(br, p, fdb_info->addr,
 181                                      fdb_info->vid, fdb_info->offloaded);
 182                 break;
 183         }
 184
 185 out:
 186         return err;
 187 }
 188
 189 static struct notifier_block br_switchdev_notifier = {
 190         .notifier_call = br_switchdev_event,
 191 };
 192
 193 /* br_boolopt_toggle - change user-controlled boolean option
 194  *
 195  * @br: bridge device
 196  * @opt: id of the option to change
 197  * @on: new option value
 198  * @extack: extack for error messages
 199  *
 200  * Changes the value of the respective boolean option to @on taking care of
 201  * any internal option value mapping and configuration.
 202  */
 203 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on,
 204                       struct netlink_ext_ack *extack)
 205 {
 206         switch (opt) {
 207         case BR_BOOLOPT_NO_LL_LEARN:
 208                 br_opt_toggle(br, BROPT_NO_LL_LEARN, on);
 209                 break;
 210         default:
 211                 /* shouldn't be called with unsupported options */
 212                 WARN_ON(1);
 213                 break;
 214         }
 215
 216         return 0;
 217 }
 218
 219 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt)
 220 {
 221         switch (opt) {
 222         case BR_BOOLOPT_NO_LL_LEARN:
 223                 return br_opt_get(br, BROPT_NO_LL_LEARN);
 224         default:
 225                 /* shouldn't be called with unsupported options */
 226                 WARN_ON(1);
 227                 break;
 228         }
 229
 230         return 0;
 231 }
 232
 233 int br_boolopt_multi_toggle(struct net_bridge *br,
 234                             struct br_boolopt_multi *bm,
 235                             struct netlink_ext_ack *extack)
 236 {
 237         unsigned long bitmap = bm->optmask;
 238         int err = 0;
 239         int opt_id;
 240
 241         for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) {
 242                 bool on = !!(bm->optval & BIT(opt_id));
 243
 244                 err = br_boolopt_toggle(br, opt_id, on, extack);
 245                 if (err) {
 246                         br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n",
 247                                  opt_id, br_boolopt_get(br, opt_id), on, err);
 248                         break;
 249                 }
 250         }
 251
 252         return err;
 253 }
 254
 255 void br_boolopt_multi_get(const struct net_bridge *br,
 256                           struct br_boolopt_multi *bm)
 257 {
 258         u32 optval = 0;
 259         int opt_id;
 260
 261         for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++)
 262                 optval |= (br_boolopt_get(br, opt_id) << opt_id);
 263
 264         bm->optval = optval;
 265         bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0);
 266 }
 267
 268 /* private bridge options, controlled by the kernel */
 269 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on)
 270 {
 271         bool cur = !!br_opt_get(br, opt);
 272
 273         br_debug(br, "toggle option: %d state: %d -> %d\n",
 274                  opt, cur, on);
 275
 276         if (cur == on)
 277                 return;
 278
 279         if (on)
 280                 set_bit(opt, &br->options);
 281         else
 282                 clear_bit(opt, &br->options);
 283 }
 284
 285 static void __net_exit br_net_exit(struct net *net)
 286 {
 287         struct net_device *dev;
 288         LIST_HEAD(list);
 289
 290         rtnl_lock();
 291         for_each_netdev(net, dev)
 292                 if (dev->priv_flags & IFF_EBRIDGE)
 293                         br_dev_delete(dev, &list);
 294
 295         unregister_netdevice_many(&list);
 296         rtnl_unlock();
 297
 298 }
 299
 300 static struct pernet_operations br_net_ops = {
 301         .exit   = br_net_exit,
 302 };
 303
 304 static const struct stp_proto br_stp_proto = {
 305         .rcv    = br_stp_rcv,
 306 };
 307
 308 static int __init br_init(void)
 309 {
 310         int err;
 311
 312         BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(struct sk_buff, cb));
 313
 314         err = stp_proto_register(&br_stp_proto);
 315         if (err < 0) {
 316                 pr_err("bridge: can't register sap for STP\n");
 317                 return err;
 318         }
 319
 320         err = br_fdb_init();
 321         if (err)
 322                 goto err_out;
 323
 324         err = register_pernet_subsys(&br_net_ops);
 325         if (err)
 326                 goto err_out1;
 327
 328         err = br_nf_core_init();
 329         if (err)
 330                 goto err_out2;
 331
 332         err = register_netdevice_notifier(&br_device_notifier);
 333         if (err)
 334                 goto err_out3;
 335
 336         err = register_switchdev_notifier(&br_switchdev_notifier);
 337         if (err)
 338                 goto err_out4;
 339
 340         err = br_netlink_init();
 341         if (err)
 342                 goto err_out5;
 343
 344         brioctl_set(br_ioctl_deviceless_stub);
 345
 346 #if IS_ENABLED(CONFIG_ATM_LANE)
 347         br_fdb_test_addr_hook = br_fdb_test_addr;
 348 #endif
 349
 350 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER)
 351         pr_info("bridge: filtering via arp/ip/ip6tables is no longer available "
 352                 "by default. Update your scripts to load br_netfilter if you "
 353                 "need this.\n");
 354 #endif
 355
 356         return 0;
 357
 358 err_out5:
 359         unregister_switchdev_notifier(&br_switchdev_notifier);
 360 err_out4:
 361         unregister_netdevice_notifier(&br_device_notifier);
 362 err_out3:
 363         br_nf_core_fini();
 364 err_out2:
 365         unregister_pernet_subsys(&br_net_ops);
 366 err_out1:
 367         br_fdb_fini();
 368 err_out:
 369         stp_proto_unregister(&br_stp_proto);
 370         return err;
 371 }
 372
 373 static void __exit br_deinit(void)
 374 {
 375         stp_proto_unregister(&br_stp_proto);
 376         br_netlink_fini();
 377         unregister_switchdev_notifier(&br_switchdev_notifier);
 378         unregister_netdevice_notifier(&br_device_notifier);
 379         brioctl_set(NULL);
 380         unregister_pernet_subsys(&br_net_ops);
 381
 382         rcu_barrier(); /* Wait for completion of call_rcu()'s */
 383
 384         br_nf_core_fini();
 385 #if IS_ENABLED(CONFIG_ATM_LANE)
 386         br_fdb_test_addr_hook = NULL;
 387 #endif
 388         br_fdb_fini();
 389 }
 390
 391 module_init(br_init)
 392 module_exit(br_deinit)
 393 MODULE_LICENSE("GPL");
 394 MODULE_VERSION(BR_VERSION);
 395 MODULE_ALIAS_RTNL_LINK("bridge");