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 (netif_is_bridge_master(dev)) { 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 err = br_sysfs_addbr(dev); 47 if (err) 48 return notifier_from_errno(err); 49 50 return NOTIFY_DONE; 51 } 52 } 53 54 /* not a port of a bridge */ 55 p = br_port_get_rtnl(dev); 56 if (!p) 57 return NOTIFY_DONE; 58 59 br = p->br; 60 61 switch (event) { 62 case NETDEV_CHANGEMTU: 63 br_mtu_auto_adjust(br); 64 break; 65 66 case NETDEV_PRE_CHANGEADDR: 67 if (br->dev->addr_assign_type == NET_ADDR_SET) 68 break; 69 prechaddr_info = ptr; 70 err = dev_pre_changeaddr_notify(br->dev, 71 prechaddr_info->dev_addr, 72 extack); 73 if (err) 74 return notifier_from_errno(err); 75 break; 76 77 case NETDEV_CHANGEADDR: 78 spin_lock_bh(&br->lock); 79 br_fdb_changeaddr(p, dev->dev_addr); 80 changed_addr = br_stp_recalculate_bridge_id(br); 81 spin_unlock_bh(&br->lock); 82 83 if (changed_addr) 84 call_netdevice_notifiers(NETDEV_CHANGEADDR, br->dev); 85 86 break; 87 88 case NETDEV_CHANGE: 89 br_port_carrier_check(p, ¬ified); 90 break; 91 92 case NETDEV_FEAT_CHANGE: 93 netdev_update_features(br->dev); 94 break; 95 96 case NETDEV_DOWN: 97 spin_lock_bh(&br->lock); 98 if (br->dev->flags & IFF_UP) { 99 br_stp_disable_port(p); 100 notified = true; 101 } 102 spin_unlock_bh(&br->lock); 103 break; 104 105 case NETDEV_UP: 106 if (netif_running(br->dev) && netif_oper_up(dev)) { 107 spin_lock_bh(&br->lock); 108 br_stp_enable_port(p); 109 notified = true; 110 spin_unlock_bh(&br->lock); 111 } 112 break; 113 114 case NETDEV_UNREGISTER: 115 br_del_if(br, dev); 116 break; 117 118 case NETDEV_CHANGENAME: 119 err = br_sysfs_renameif(p); 120 if (err) 121 return notifier_from_errno(err); 122 break; 123 124 case NETDEV_PRE_TYPE_CHANGE: 125 /* Forbid underlying device to change its type. */ 126 return NOTIFY_BAD; 127 128 case NETDEV_RESEND_IGMP: 129 /* Propagate to master device */ 130 call_netdevice_notifiers(event, br->dev); 131 break; 132 } 133 134 if (event != NETDEV_UNREGISTER) 135 br_vlan_port_event(p, event); 136 137 /* Events that may cause spanning tree to refresh */ 138 if (!notified && (event == NETDEV_CHANGEADDR || event == NETDEV_UP || 139 event == NETDEV_CHANGE || event == NETDEV_DOWN)) 140 br_ifinfo_notify(RTM_NEWLINK, NULL, p); 141 142 return NOTIFY_DONE; 143 } 144 145 static struct notifier_block br_device_notifier = { 146 .notifier_call = br_device_event 147 }; 148 149 /* called with RTNL or RCU */ 150 static int br_switchdev_event(struct notifier_block *unused, 151 unsigned long event, void *ptr) 152 { 153 struct net_device *dev = switchdev_notifier_info_to_dev(ptr); 154 struct net_bridge_port *p; 155 struct net_bridge *br; 156 struct switchdev_notifier_fdb_info *fdb_info; 157 int err = NOTIFY_DONE; 158 159 p = br_port_get_rtnl_rcu(dev); 160 if (!p) 161 goto out; 162 163 br = p->br; 164 165 switch (event) { 166 case SWITCHDEV_FDB_ADD_TO_BRIDGE: 167 fdb_info = ptr; 168 err = br_fdb_external_learn_add(br, p, fdb_info->addr, 169 fdb_info->vid, 170 fdb_info->locked, false); 171 if (err) { 172 err = notifier_from_errno(err); 173 break; 174 } 175 br_fdb_offloaded_set(br, p, fdb_info->addr, 176 fdb_info->vid, fdb_info->offloaded); 177 break; 178 case SWITCHDEV_FDB_DEL_TO_BRIDGE: 179 fdb_info = ptr; 180 err = br_fdb_external_learn_del(br, p, fdb_info->addr, 181 fdb_info->vid, false); 182 if (err) 183 err = notifier_from_errno(err); 184 break; 185 case SWITCHDEV_FDB_OFFLOADED: 186 fdb_info = ptr; 187 br_fdb_offloaded_set(br, p, fdb_info->addr, 188 fdb_info->vid, fdb_info->offloaded); 189 break; 190 case SWITCHDEV_FDB_FLUSH_TO_BRIDGE: 191 fdb_info = ptr; 192 /* Don't delete static entries */ 193 br_fdb_delete_by_port(br, p, fdb_info->vid, 0); 194 break; 195 } 196 197 out: 198 return err; 199 } 200 201 static struct notifier_block br_switchdev_notifier = { 202 .notifier_call = br_switchdev_event, 203 }; 204 205 /* called under rtnl_mutex */ 206 static int br_switchdev_blocking_event(struct notifier_block *nb, 207 unsigned long event, void *ptr) 208 { 209 struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(ptr); 210 struct net_device *dev = switchdev_notifier_info_to_dev(ptr); 211 struct switchdev_notifier_brport_info *brport_info; 212 const struct switchdev_brport *b; 213 struct net_bridge_port *p; 214 int err = NOTIFY_DONE; 215 216 p = br_port_get_rtnl(dev); 217 if (!p) 218 goto out; 219 220 switch (event) { 221 case SWITCHDEV_BRPORT_OFFLOADED: 222 brport_info = ptr; 223 b = &brport_info->brport; 224 225 err = br_switchdev_port_offload(p, b->dev, b->ctx, 226 b->atomic_nb, b->blocking_nb, 227 b->tx_fwd_offload, extack); 228 err = notifier_from_errno(err); 229 break; 230 case SWITCHDEV_BRPORT_UNOFFLOADED: 231 brport_info = ptr; 232 b = &brport_info->brport; 233 234 br_switchdev_port_unoffload(p, b->ctx, b->atomic_nb, 235 b->blocking_nb); 236 break; 237 } 238 239 out: 240 return err; 241 } 242 243 static struct notifier_block br_switchdev_blocking_notifier = { 244 .notifier_call = br_switchdev_blocking_event, 245 }; 246 247 /* br_boolopt_toggle - change user-controlled boolean option 248 * 249 * @br: bridge device 250 * @opt: id of the option to change 251 * @on: new option value 252 * @extack: extack for error messages 253 * 254 * Changes the value of the respective boolean option to @on taking care of 255 * any internal option value mapping and configuration. 256 */ 257 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on, 258 struct netlink_ext_ack *extack) 259 { 260 int err = 0; 261 262 switch (opt) { 263 case BR_BOOLOPT_NO_LL_LEARN: 264 br_opt_toggle(br, BROPT_NO_LL_LEARN, on); 265 break; 266 case BR_BOOLOPT_MCAST_VLAN_SNOOPING: 267 err = br_multicast_toggle_vlan_snooping(br, on, extack); 268 break; 269 case BR_BOOLOPT_MST_ENABLE: 270 err = br_mst_set_enabled(br, on, extack); 271 break; 272 default: 273 /* shouldn't be called with unsupported options */ 274 WARN_ON(1); 275 break; 276 } 277 278 return err; 279 } 280 281 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt) 282 { 283 switch (opt) { 284 case BR_BOOLOPT_NO_LL_LEARN: 285 return br_opt_get(br, BROPT_NO_LL_LEARN); 286 case BR_BOOLOPT_MCAST_VLAN_SNOOPING: 287 return br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED); 288 case BR_BOOLOPT_MST_ENABLE: 289 return br_opt_get(br, BROPT_MST_ENABLED); 290 default: 291 /* shouldn't be called with unsupported options */ 292 WARN_ON(1); 293 break; 294 } 295 296 return 0; 297 } 298 299 int br_boolopt_multi_toggle(struct net_bridge *br, 300 struct br_boolopt_multi *bm, 301 struct netlink_ext_ack *extack) 302 { 303 unsigned long bitmap = bm->optmask; 304 int err = 0; 305 int opt_id; 306 307 for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) { 308 bool on = !!(bm->optval & BIT(opt_id)); 309 310 err = br_boolopt_toggle(br, opt_id, on, extack); 311 if (err) { 312 br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n", 313 opt_id, br_boolopt_get(br, opt_id), on, err); 314 break; 315 } 316 } 317 318 return err; 319 } 320 321 void br_boolopt_multi_get(const struct net_bridge *br, 322 struct br_boolopt_multi *bm) 323 { 324 u32 optval = 0; 325 int opt_id; 326 327 for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++) 328 optval |= (br_boolopt_get(br, opt_id) << opt_id); 329 330 bm->optval = optval; 331 bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0); 332 } 333 334 /* private bridge options, controlled by the kernel */ 335 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on) 336 { 337 bool cur = !!br_opt_get(br, opt); 338 339 br_debug(br, "toggle option: %d state: %d -> %d\n", 340 opt, cur, on); 341 342 if (cur == on) 343 return; 344 345 if (on) 346 set_bit(opt, &br->options); 347 else 348 clear_bit(opt, &br->options); 349 } 350 351 static void __net_exit br_net_exit_batch(struct list_head *net_list) 352 { 353 struct net_device *dev; 354 struct net *net; 355 LIST_HEAD(list); 356 357 rtnl_lock(); 358 359 list_for_each_entry(net, net_list, exit_list) 360 for_each_netdev(net, dev) 361 if (netif_is_bridge_master(dev)) 362 br_dev_delete(dev, &list); 363 364 unregister_netdevice_many(&list); 365 366 rtnl_unlock(); 367 } 368 369 static struct pernet_operations br_net_ops = { 370 .exit_batch = br_net_exit_batch, 371 }; 372 373 static const struct stp_proto br_stp_proto = { 374 .rcv = br_stp_rcv, 375 }; 376 377 static int __init br_init(void) 378 { 379 int err; 380 381 BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb)); 382 383 err = stp_proto_register(&br_stp_proto); 384 if (err < 0) { 385 pr_err("bridge: can't register sap for STP\n"); 386 return err; 387 } 388 389 err = br_fdb_init(); 390 if (err) 391 goto err_out; 392 393 err = register_pernet_subsys(&br_net_ops); 394 if (err) 395 goto err_out1; 396 397 err = br_nf_core_init(); 398 if (err) 399 goto err_out2; 400 401 err = register_netdevice_notifier(&br_device_notifier); 402 if (err) 403 goto err_out3; 404 405 err = register_switchdev_notifier(&br_switchdev_notifier); 406 if (err) 407 goto err_out4; 408 409 err = register_switchdev_blocking_notifier(&br_switchdev_blocking_notifier); 410 if (err) 411 goto err_out5; 412 413 err = br_netlink_init(); 414 if (err) 415 goto err_out6; 416 417 brioctl_set(br_ioctl_stub); 418 419 #if IS_ENABLED(CONFIG_ATM_LANE) 420 br_fdb_test_addr_hook = br_fdb_test_addr; 421 #endif 422 423 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER) 424 pr_info("bridge: filtering via arp/ip/ip6tables is no longer available " 425 "by default. Update your scripts to load br_netfilter if you " 426 "need this.\n"); 427 #endif 428 429 return 0; 430 431 err_out6: 432 unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier); 433 err_out5: 434 unregister_switchdev_notifier(&br_switchdev_notifier); 435 err_out4: 436 unregister_netdevice_notifier(&br_device_notifier); 437 err_out3: 438 br_nf_core_fini(); 439 err_out2: 440 unregister_pernet_subsys(&br_net_ops); 441 err_out1: 442 br_fdb_fini(); 443 err_out: 444 stp_proto_unregister(&br_stp_proto); 445 return err; 446 } 447 448 static void __exit br_deinit(void) 449 { 450 stp_proto_unregister(&br_stp_proto); 451 br_netlink_fini(); 452 unregister_switchdev_blocking_notifier(&br_switchdev_blocking_notifier); 453 unregister_switchdev_notifier(&br_switchdev_notifier); 454 unregister_netdevice_notifier(&br_device_notifier); 455 brioctl_set(NULL); 456 unregister_pernet_subsys(&br_net_ops); 457 458 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 459 460 br_nf_core_fini(); 461 #if IS_ENABLED(CONFIG_ATM_LANE) 462 br_fdb_test_addr_hook = NULL; 463 #endif 464 br_fdb_fini(); 465 } 466 467 module_init(br_init) 468 module_exit(br_deinit) 469 MODULE_LICENSE("GPL"); 470 MODULE_VERSION(BR_VERSION); 471 MODULE_ALIAS_RTNL_LINK("bridge"); 472