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 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, false); 170 if (err) { 171 err = notifier_from_errno(err); 172 break; 173 } 174 br_fdb_offloaded_set(br, p, fdb_info->addr, 175 fdb_info->vid, true); 176 break; 177 case SWITCHDEV_FDB_DEL_TO_BRIDGE: 178 fdb_info = ptr; 179 err = br_fdb_external_learn_del(br, p, fdb_info->addr, 180 fdb_info->vid, false); 181 if (err) 182 err = notifier_from_errno(err); 183 break; 184 case SWITCHDEV_FDB_OFFLOADED: 185 fdb_info = ptr; 186 br_fdb_offloaded_set(br, p, fdb_info->addr, 187 fdb_info->vid, fdb_info->offloaded); 188 break; 189 case SWITCHDEV_FDB_FLUSH_TO_BRIDGE: 190 fdb_info = ptr; 191 /* Don't delete static entries */ 192 br_fdb_delete_by_port(br, p, fdb_info->vid, 0); 193 break; 194 } 195 196 out: 197 return err; 198 } 199 200 static struct notifier_block br_switchdev_notifier = { 201 .notifier_call = br_switchdev_event, 202 }; 203 204 /* br_boolopt_toggle - change user-controlled boolean option 205 * 206 * @br: bridge device 207 * @opt: id of the option to change 208 * @on: new option value 209 * @extack: extack for error messages 210 * 211 * Changes the value of the respective boolean option to @on taking care of 212 * any internal option value mapping and configuration. 213 */ 214 int br_boolopt_toggle(struct net_bridge *br, enum br_boolopt_id opt, bool on, 215 struct netlink_ext_ack *extack) 216 { 217 int err = 0; 218 219 switch (opt) { 220 case BR_BOOLOPT_NO_LL_LEARN: 221 br_opt_toggle(br, BROPT_NO_LL_LEARN, on); 222 break; 223 case BR_BOOLOPT_MCAST_VLAN_SNOOPING: 224 err = br_multicast_toggle_vlan_snooping(br, on, extack); 225 break; 226 default: 227 /* shouldn't be called with unsupported options */ 228 WARN_ON(1); 229 break; 230 } 231 232 return err; 233 } 234 235 int br_boolopt_get(const struct net_bridge *br, enum br_boolopt_id opt) 236 { 237 switch (opt) { 238 case BR_BOOLOPT_NO_LL_LEARN: 239 return br_opt_get(br, BROPT_NO_LL_LEARN); 240 case BR_BOOLOPT_MCAST_VLAN_SNOOPING: 241 return br_opt_get(br, BROPT_MCAST_VLAN_SNOOPING_ENABLED); 242 default: 243 /* shouldn't be called with unsupported options */ 244 WARN_ON(1); 245 break; 246 } 247 248 return 0; 249 } 250 251 int br_boolopt_multi_toggle(struct net_bridge *br, 252 struct br_boolopt_multi *bm, 253 struct netlink_ext_ack *extack) 254 { 255 unsigned long bitmap = bm->optmask; 256 int err = 0; 257 int opt_id; 258 259 for_each_set_bit(opt_id, &bitmap, BR_BOOLOPT_MAX) { 260 bool on = !!(bm->optval & BIT(opt_id)); 261 262 err = br_boolopt_toggle(br, opt_id, on, extack); 263 if (err) { 264 br_debug(br, "boolopt multi-toggle error: option: %d current: %d new: %d error: %d\n", 265 opt_id, br_boolopt_get(br, opt_id), on, err); 266 break; 267 } 268 } 269 270 return err; 271 } 272 273 void br_boolopt_multi_get(const struct net_bridge *br, 274 struct br_boolopt_multi *bm) 275 { 276 u32 optval = 0; 277 int opt_id; 278 279 for (opt_id = 0; opt_id < BR_BOOLOPT_MAX; opt_id++) 280 optval |= (br_boolopt_get(br, opt_id) << opt_id); 281 282 bm->optval = optval; 283 bm->optmask = GENMASK((BR_BOOLOPT_MAX - 1), 0); 284 } 285 286 /* private bridge options, controlled by the kernel */ 287 void br_opt_toggle(struct net_bridge *br, enum net_bridge_opts opt, bool on) 288 { 289 bool cur = !!br_opt_get(br, opt); 290 291 br_debug(br, "toggle option: %d state: %d -> %d\n", 292 opt, cur, on); 293 294 if (cur == on) 295 return; 296 297 if (on) 298 set_bit(opt, &br->options); 299 else 300 clear_bit(opt, &br->options); 301 } 302 303 static void __net_exit br_net_exit(struct net *net) 304 { 305 struct net_device *dev; 306 LIST_HEAD(list); 307 308 rtnl_lock(); 309 for_each_netdev(net, dev) 310 if (dev->priv_flags & IFF_EBRIDGE) 311 br_dev_delete(dev, &list); 312 313 unregister_netdevice_many(&list); 314 rtnl_unlock(); 315 316 } 317 318 static struct pernet_operations br_net_ops = { 319 .exit = br_net_exit, 320 }; 321 322 static const struct stp_proto br_stp_proto = { 323 .rcv = br_stp_rcv, 324 }; 325 326 static int __init br_init(void) 327 { 328 int err; 329 330 BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(struct sk_buff, cb)); 331 332 err = stp_proto_register(&br_stp_proto); 333 if (err < 0) { 334 pr_err("bridge: can't register sap for STP\n"); 335 return err; 336 } 337 338 err = br_fdb_init(); 339 if (err) 340 goto err_out; 341 342 err = register_pernet_subsys(&br_net_ops); 343 if (err) 344 goto err_out1; 345 346 err = br_nf_core_init(); 347 if (err) 348 goto err_out2; 349 350 err = register_netdevice_notifier(&br_device_notifier); 351 if (err) 352 goto err_out3; 353 354 err = register_switchdev_notifier(&br_switchdev_notifier); 355 if (err) 356 goto err_out4; 357 358 err = br_netlink_init(); 359 if (err) 360 goto err_out5; 361 362 brioctl_set(br_ioctl_deviceless_stub); 363 364 #if IS_ENABLED(CONFIG_ATM_LANE) 365 br_fdb_test_addr_hook = br_fdb_test_addr; 366 #endif 367 368 #if IS_MODULE(CONFIG_BRIDGE_NETFILTER) 369 pr_info("bridge: filtering via arp/ip/ip6tables is no longer available " 370 "by default. Update your scripts to load br_netfilter if you " 371 "need this.\n"); 372 #endif 373 374 return 0; 375 376 err_out5: 377 unregister_switchdev_notifier(&br_switchdev_notifier); 378 err_out4: 379 unregister_netdevice_notifier(&br_device_notifier); 380 err_out3: 381 br_nf_core_fini(); 382 err_out2: 383 unregister_pernet_subsys(&br_net_ops); 384 err_out1: 385 br_fdb_fini(); 386 err_out: 387 stp_proto_unregister(&br_stp_proto); 388 return err; 389 } 390 391 static void __exit br_deinit(void) 392 { 393 stp_proto_unregister(&br_stp_proto); 394 br_netlink_fini(); 395 unregister_switchdev_notifier(&br_switchdev_notifier); 396 unregister_netdevice_notifier(&br_device_notifier); 397 brioctl_set(NULL); 398 unregister_pernet_subsys(&br_net_ops); 399 400 rcu_barrier(); /* Wait for completion of call_rcu()'s */ 401 402 br_nf_core_fini(); 403 #if IS_ENABLED(CONFIG_ATM_LANE) 404 br_fdb_test_addr_hook = NULL; 405 #endif 406 br_fdb_fini(); 407 } 408 409 module_init(br_init) 410 module_exit(br_deinit) 411 MODULE_LICENSE("GPL"); 412 MODULE_VERSION(BR_VERSION); 413 MODULE_ALIAS_RTNL_LINK("bridge"); 414