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