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