linux/net/bridge/br.c
<<
>>
Prefs
   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 */
  28static 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
 142static struct notifier_block br_device_notifier = {
 143        .notifier_call = br_device_event
 144};
 145
 146/* called with RTNL or RCU */
 147static 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
 188out:
 189        return err;
 190}
 191
 192static 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 */
 206int 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
 222int 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
 236int 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
 258void 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 */
 272void 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
 288static 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
 303static struct pernet_operations br_net_ops = {
 304        .exit   = br_net_exit,
 305};
 306
 307static const struct stp_proto br_stp_proto = {
 308        .rcv    = br_stp_rcv,
 309};
 310
 311static int __init br_init(void)
 312{
 313        int err;
 314
 315        BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > FIELD_SIZEOF(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
 361err_out5:
 362        unregister_switchdev_notifier(&br_switchdev_notifier);
 363err_out4:
 364        unregister_netdevice_notifier(&br_device_notifier);
 365err_out3:
 366        br_nf_core_fini();
 367err_out2:
 368        unregister_pernet_subsys(&br_net_ops);
 369err_out1:
 370        br_fdb_fini();
 371err_out:
 372        stp_proto_unregister(&br_stp_proto);
 373        return err;
 374}
 375
 376static 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
 394module_init(br_init)
 395module_exit(br_deinit)
 396MODULE_LICENSE("GPL");
 397MODULE_VERSION(BR_VERSION);
 398MODULE_ALIAS_RTNL_LINK("bridge");
 399