1 /* 2 * Userspace interface 3 * Linux ethernet bridge 4 * 5 * Authors: 6 * Lennert Buytenhek <buytenh@gnu.org> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * as published by the Free Software Foundation; either version 11 * 2 of the License, or (at your option) any later version. 12 */ 13 14 #include <linux/kernel.h> 15 #include <linux/netdevice.h> 16 #include <linux/ethtool.h> 17 #include <linux/if_arp.h> 18 #include <linux/module.h> 19 #include <linux/init.h> 20 #include <linux/rtnetlink.h> 21 #include <linux/if_ether.h> 22 #include <net/sock.h> 23 24 #include "br_private.h" 25 26 /* 27 * Determine initial path cost based on speed. 28 * using recommendations from 802.1d standard 29 * 30 * Since driver might sleep need to not be holding any locks. 31 */ 32 static int port_cost(struct net_device *dev) 33 { 34 if (dev->ethtool_ops && dev->ethtool_ops->get_settings) { 35 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, }; 36 37 if (!dev->ethtool_ops->get_settings(dev, &ecmd)) { 38 switch(ecmd.speed) { 39 case SPEED_10000: 40 return 2; 41 case SPEED_1000: 42 return 4; 43 case SPEED_100: 44 return 19; 45 case SPEED_10: 46 return 100; 47 } 48 } 49 } 50 51 /* Old silly heuristics based on name */ 52 if (!strncmp(dev->name, "lec", 3)) 53 return 7; 54 55 if (!strncmp(dev->name, "plip", 4)) 56 return 2500; 57 58 return 100; /* assume old 10Mbps */ 59 } 60 61 62 /* 63 * Check for port carrier transistions. 64 * Called from work queue to allow for calling functions that 65 * might sleep (such as speed check), and to debounce. 66 */ 67 void br_port_carrier_check(struct net_bridge_port *p) 68 { 69 struct net_device *dev = p->dev; 70 struct net_bridge *br = p->br; 71 72 if (netif_carrier_ok(dev)) 73 p->path_cost = port_cost(dev); 74 75 if (netif_running(br->dev)) { 76 spin_lock_bh(&br->lock); 77 if (netif_carrier_ok(dev)) { 78 if (p->state == BR_STATE_DISABLED) 79 br_stp_enable_port(p); 80 } else { 81 if (p->state != BR_STATE_DISABLED) 82 br_stp_disable_port(p); 83 } 84 spin_unlock_bh(&br->lock); 85 } 86 } 87 88 static void release_nbp(struct kobject *kobj) 89 { 90 struct net_bridge_port *p 91 = container_of(kobj, struct net_bridge_port, kobj); 92 kfree(p); 93 } 94 95 static struct kobj_type brport_ktype = { 96 #ifdef CONFIG_SYSFS 97 .sysfs_ops = &brport_sysfs_ops, 98 #endif 99 .release = release_nbp, 100 }; 101 102 static void destroy_nbp(struct net_bridge_port *p) 103 { 104 struct net_device *dev = p->dev; 105 106 p->br = NULL; 107 p->dev = NULL; 108 dev_put(dev); 109 110 kobject_put(&p->kobj); 111 } 112 113 static void destroy_nbp_rcu(struct rcu_head *head) 114 { 115 struct net_bridge_port *p = 116 container_of(head, struct net_bridge_port, rcu); 117 destroy_nbp(p); 118 } 119 120 /* Delete port(interface) from bridge is done in two steps. 121 * via RCU. First step, marks device as down. That deletes 122 * all the timers and stops new packets from flowing through. 123 * 124 * Final cleanup doesn't occur until after all CPU's finished 125 * processing packets. 126 * 127 * Protected from multiple admin operations by RTNL mutex 128 */ 129 static void del_nbp(struct net_bridge_port *p) 130 { 131 struct net_bridge *br = p->br; 132 struct net_device *dev = p->dev; 133 134 sysfs_remove_link(br->ifobj, dev->name); 135 136 dev_set_promiscuity(dev, -1); 137 138 spin_lock_bh(&br->lock); 139 br_stp_disable_port(p); 140 spin_unlock_bh(&br->lock); 141 142 br_ifinfo_notify(RTM_DELLINK, p); 143 144 br_fdb_delete_by_port(br, p, 1); 145 146 list_del_rcu(&p->list); 147 148 rcu_assign_pointer(dev->br_port, NULL); 149 150 kobject_uevent(&p->kobj, KOBJ_REMOVE); 151 kobject_del(&p->kobj); 152 153 call_rcu(&p->rcu, destroy_nbp_rcu); 154 } 155 156 /* called with RTNL */ 157 static void del_br(struct net_bridge *br, struct list_head *head) 158 { 159 struct net_bridge_port *p, *n; 160 161 list_for_each_entry_safe(p, n, &br->port_list, list) { 162 del_nbp(p); 163 } 164 165 del_timer_sync(&br->gc_timer); 166 167 br_sysfs_delbr(br->dev); 168 unregister_netdevice_queue(br->dev, head); 169 } 170 171 static struct net_device *new_bridge_dev(struct net *net, const char *name) 172 { 173 struct net_bridge *br; 174 struct net_device *dev; 175 176 dev = alloc_netdev(sizeof(struct net_bridge), name, 177 br_dev_setup); 178 179 if (!dev) 180 return NULL; 181 dev_net_set(dev, net); 182 183 br = netdev_priv(dev); 184 br->dev = dev; 185 186 spin_lock_init(&br->lock); 187 INIT_LIST_HEAD(&br->port_list); 188 spin_lock_init(&br->hash_lock); 189 190 br->bridge_id.prio[0] = 0x80; 191 br->bridge_id.prio[1] = 0x00; 192 193 memcpy(br->group_addr, br_group_address, ETH_ALEN); 194 195 br->feature_mask = dev->features; 196 br->stp_enabled = BR_NO_STP; 197 br->designated_root = br->bridge_id; 198 br->root_path_cost = 0; 199 br->root_port = 0; 200 br->bridge_max_age = br->max_age = 20 * HZ; 201 br->bridge_hello_time = br->hello_time = 2 * HZ; 202 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 203 br->topology_change = 0; 204 br->topology_change_detected = 0; 205 br->ageing_time = 300 * HZ; 206 207 br_netfilter_rtable_init(br); 208 209 INIT_LIST_HEAD(&br->age_list); 210 211 br_stp_timer_init(br); 212 213 return dev; 214 } 215 216 /* find an available port number */ 217 static int find_portno(struct net_bridge *br) 218 { 219 int index; 220 struct net_bridge_port *p; 221 unsigned long *inuse; 222 223 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 224 GFP_KERNEL); 225 if (!inuse) 226 return -ENOMEM; 227 228 set_bit(0, inuse); /* zero is reserved */ 229 list_for_each_entry(p, &br->port_list, list) { 230 set_bit(p->port_no, inuse); 231 } 232 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 233 kfree(inuse); 234 235 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 236 } 237 238 /* called with RTNL but without bridge lock */ 239 static struct net_bridge_port *new_nbp(struct net_bridge *br, 240 struct net_device *dev) 241 { 242 int index; 243 struct net_bridge_port *p; 244 245 index = find_portno(br); 246 if (index < 0) 247 return ERR_PTR(index); 248 249 p = kzalloc(sizeof(*p), GFP_KERNEL); 250 if (p == NULL) 251 return ERR_PTR(-ENOMEM); 252 253 p->br = br; 254 dev_hold(dev); 255 p->dev = dev; 256 p->path_cost = port_cost(dev); 257 p->priority = 0x8000 >> BR_PORT_BITS; 258 p->port_no = index; 259 p->flags = 0; 260 br_init_port(p); 261 p->state = BR_STATE_DISABLED; 262 br_stp_port_timer_init(p); 263 264 return p; 265 } 266 267 static struct device_type br_type = { 268 .name = "bridge", 269 }; 270 271 int br_add_bridge(struct net *net, const char *name) 272 { 273 struct net_device *dev; 274 int ret; 275 276 dev = new_bridge_dev(net, name); 277 if (!dev) 278 return -ENOMEM; 279 280 rtnl_lock(); 281 if (strchr(dev->name, '%')) { 282 ret = dev_alloc_name(dev, dev->name); 283 if (ret < 0) 284 goto out_free; 285 } 286 287 SET_NETDEV_DEVTYPE(dev, &br_type); 288 289 ret = register_netdevice(dev); 290 if (ret) 291 goto out_free; 292 293 ret = br_sysfs_addbr(dev); 294 if (ret) 295 unregister_netdevice(dev); 296 out: 297 rtnl_unlock(); 298 return ret; 299 300 out_free: 301 free_netdev(dev); 302 goto out; 303 } 304 305 int br_del_bridge(struct net *net, const char *name) 306 { 307 struct net_device *dev; 308 int ret = 0; 309 310 rtnl_lock(); 311 dev = __dev_get_by_name(net, name); 312 if (dev == NULL) 313 ret = -ENXIO; /* Could not find device */ 314 315 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 316 /* Attempt to delete non bridge device! */ 317 ret = -EPERM; 318 } 319 320 else if (dev->flags & IFF_UP) { 321 /* Not shutdown yet. */ 322 ret = -EBUSY; 323 } 324 325 else 326 del_br(netdev_priv(dev), NULL); 327 328 rtnl_unlock(); 329 return ret; 330 } 331 332 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 333 int br_min_mtu(const struct net_bridge *br) 334 { 335 const struct net_bridge_port *p; 336 int mtu = 0; 337 338 ASSERT_RTNL(); 339 340 if (list_empty(&br->port_list)) 341 mtu = ETH_DATA_LEN; 342 else { 343 list_for_each_entry(p, &br->port_list, list) { 344 if (!mtu || p->dev->mtu < mtu) 345 mtu = p->dev->mtu; 346 } 347 } 348 return mtu; 349 } 350 351 /* 352 * Recomputes features using slave's features 353 */ 354 void br_features_recompute(struct net_bridge *br) 355 { 356 struct net_bridge_port *p; 357 unsigned long features, mask; 358 359 features = mask = br->feature_mask; 360 if (list_empty(&br->port_list)) 361 goto done; 362 363 features &= ~NETIF_F_ONE_FOR_ALL; 364 365 list_for_each_entry(p, &br->port_list, list) { 366 features = netdev_increment_features(features, 367 p->dev->features, mask); 368 } 369 370 done: 371 br->dev->features = netdev_fix_features(features, NULL); 372 } 373 374 /* called with RTNL */ 375 int br_add_if(struct net_bridge *br, struct net_device *dev) 376 { 377 struct net_bridge_port *p; 378 int err = 0; 379 380 /* Don't allow bridging non-ethernet like devices */ 381 if ((dev->flags & IFF_LOOPBACK) || 382 dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN) 383 return -EINVAL; 384 385 /* No bridging of bridges */ 386 if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit) 387 return -ELOOP; 388 389 /* Device is already being bridged */ 390 if (dev->br_port != NULL) 391 return -EBUSY; 392 393 /* No bridging devices that dislike that (e.g. wireless) */ 394 if (dev->priv_flags & IFF_DONT_BRIDGE) 395 return -EOPNOTSUPP; 396 397 p = new_nbp(br, dev); 398 if (IS_ERR(p)) 399 return PTR_ERR(p); 400 401 err = dev_set_promiscuity(dev, 1); 402 if (err) 403 goto put_back; 404 405 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 406 SYSFS_BRIDGE_PORT_ATTR); 407 if (err) 408 goto err0; 409 410 err = br_fdb_insert(br, p, dev->dev_addr); 411 if (err) 412 goto err1; 413 414 err = br_sysfs_addif(p); 415 if (err) 416 goto err2; 417 418 rcu_assign_pointer(dev->br_port, p); 419 dev_disable_lro(dev); 420 421 list_add_rcu(&p->list, &br->port_list); 422 423 spin_lock_bh(&br->lock); 424 br_stp_recalculate_bridge_id(br); 425 br_features_recompute(br); 426 427 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && 428 (br->dev->flags & IFF_UP)) 429 br_stp_enable_port(p); 430 spin_unlock_bh(&br->lock); 431 432 br_ifinfo_notify(RTM_NEWLINK, p); 433 434 dev_set_mtu(br->dev, br_min_mtu(br)); 435 436 kobject_uevent(&p->kobj, KOBJ_ADD); 437 438 return 0; 439 err2: 440 br_fdb_delete_by_port(br, p, 1); 441 err1: 442 kobject_put(&p->kobj); 443 p = NULL; /* kobject_put frees */ 444 err0: 445 dev_set_promiscuity(dev, -1); 446 put_back: 447 dev_put(dev); 448 kfree(p); 449 return err; 450 } 451 452 /* called with RTNL */ 453 int br_del_if(struct net_bridge *br, struct net_device *dev) 454 { 455 struct net_bridge_port *p = dev->br_port; 456 457 if (!p || p->br != br) 458 return -EINVAL; 459 460 del_nbp(p); 461 462 spin_lock_bh(&br->lock); 463 br_stp_recalculate_bridge_id(br); 464 br_features_recompute(br); 465 spin_unlock_bh(&br->lock); 466 467 return 0; 468 } 469 470 void __net_exit br_net_exit(struct net *net) 471 { 472 struct net_device *dev; 473 LIST_HEAD(list); 474 475 rtnl_lock(); 476 for_each_netdev(net, dev) 477 if (dev->priv_flags & IFF_EBRIDGE) 478 del_br(netdev_priv(dev), &list); 479 480 unregister_netdevice_many(&list); 481 rtnl_unlock(); 482 483 } 484