net/bridge/br.c

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