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 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, ¬ified); 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 } 141 142 static struct notifier_block br_device_notifier = { 143 .notifier_call = br_device_event 144 }; 145 146 /* called with RTNL or RCU */ 147 static 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 } 187 188 out: 189 return err; 190 } 191 192 static 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 */ 206 int 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 } 221 222 int 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 } 235 236 int 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 } 257 258 void 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 */ 272 void 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 } 287 288 static 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 } 302 303 static struct pernet_operations br_net_ops = { 304 .exit = br_net_exit, 305 }; 306 307 static const struct stp_proto br_stp_proto = { 308 .rcv = br_stp_rcv, 309 }; 310 311 static int __init br_init(void) 312 { 313 int err; 314 315 BUILD_BUG_ON(sizeof(struct br_input_skb_cb) > sizeof_field(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; 360 361 err_out5: 362 unregister_switchdev_notifier(&br_switchdev_notifier); 363 err_out4: 364 unregister_netdevice_notifier(&br_device_notifier); 365 err_out3: 366 br_nf_core_fini(); 367 err_out2: 368 unregister_pernet_subsys(&br_net_ops); 369 err_out1: 370 br_fdb_fini(); 371 err_out: 372 stp_proto_unregister(&br_stp_proto); 373 return err; 374 } 375 376 static 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 } 393 394 module_init(br_init) 395 module_exit(br_deinit) 396 MODULE_LICENSE("GPL"); 397 MODULE_VERSION(BR_VERSION); 398 MODULE_ALIAS_RTNL_LINK("bridge"); 399