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