1 /* 2 * Userspace interface 3 * Linux ethernet bridge 4 * 5 * Authors: 6 * Lennert Buytenhek <buytenh@gnu.org> 7 * 8 * $Id: br_if.c,v 1.7 2001/12/24 00:59:55 davem Exp $ 9 * 10 * This program is free software; you can redistribute it and/or 11 * modify it under the terms of the GNU General Public License 12 * as published by the Free Software Foundation; either version 13 * 2 of the License, or (at your option) any later version. 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/netdevice.h> 18 #include <linux/ethtool.h> 19 #include <linux/if_arp.h> 20 #include <linux/module.h> 21 #include <linux/init.h> 22 #include <linux/rtnetlink.h> 23 #include <linux/if_ether.h> 24 #include <net/sock.h> 25 26 #include "br_private.h" 27 28 /* 29 * Determine initial path cost based on speed. 30 * using recommendations from 802.1d standard 31 * 32 * Need to simulate user ioctl because not all device's that support 33 * ethtool, use ethtool_ops. Also, since driver might sleep need to 34 * not be holding any locks. 35 */ 36 static int port_cost(struct net_device *dev) 37 { 38 struct ethtool_cmd ecmd = { ETHTOOL_GSET }; 39 struct ifreq ifr; 40 mm_segment_t old_fs; 41 int err; 42 43 strncpy(ifr.ifr_name, dev->name, IFNAMSIZ); 44 ifr.ifr_data = (void __user *) &ecmd; 45 46 old_fs = get_fs(); 47 set_fs(KERNEL_DS); 48 err = dev_ethtool(&ifr); 49 set_fs(old_fs); 50 51 if (!err) { 52 switch(ecmd.speed) { 53 case SPEED_100: 54 return 19; 55 case SPEED_1000: 56 return 4; 57 case SPEED_10000: 58 return 2; 59 case SPEED_10: 60 return 100; 61 } 62 } 63 64 /* Old silly heuristics based on name */ 65 if (!strncmp(dev->name, "lec", 3)) 66 return 7; 67 68 if (!strncmp(dev->name, "plip", 4)) 69 return 2500; 70 71 return 100; /* assume old 10Mbps */ 72 } 73 74 75 /* 76 * Check for port carrier transistions. 77 * Called from work queue to allow for calling functions that 78 * might sleep (such as speed check), and to debounce. 79 */ 80 static void port_carrier_check(void *arg) 81 { 82 struct net_device *dev = arg; 83 struct net_bridge_port *p; 84 struct net_bridge *br; 85 86 rtnl_lock(); 87 p = dev->br_port; 88 if (!p) 89 goto done; 90 br = p->br; 91 92 if (netif_carrier_ok(dev)) 93 p->path_cost = port_cost(dev); 94 95 if (br->dev->flags & IFF_UP) { 96 spin_lock_bh(&br->lock); 97 if (netif_carrier_ok(dev)) { 98 if (p->state == BR_STATE_DISABLED) 99 br_stp_enable_port(p); 100 } else { 101 if (p->state != BR_STATE_DISABLED) 102 br_stp_disable_port(p); 103 } 104 spin_unlock_bh(&br->lock); 105 } 106 done: 107 rtnl_unlock(); 108 } 109 110 static void release_nbp(struct kobject *kobj) 111 { 112 struct net_bridge_port *p 113 = container_of(kobj, struct net_bridge_port, kobj); 114 kfree(p); 115 } 116 117 static struct kobj_type brport_ktype = { 118 #ifdef CONFIG_SYSFS 119 .sysfs_ops = &brport_sysfs_ops, 120 #endif 121 .release = release_nbp, 122 }; 123 124 static void destroy_nbp(struct net_bridge_port *p) 125 { 126 struct net_device *dev = p->dev; 127 128 p->br = NULL; 129 p->dev = NULL; 130 dev_put(dev); 131 132 kobject_put(&p->kobj); 133 } 134 135 static void destroy_nbp_rcu(struct rcu_head *head) 136 { 137 struct net_bridge_port *p = 138 container_of(head, struct net_bridge_port, rcu); 139 destroy_nbp(p); 140 } 141 142 /* Delete port(interface) from bridge is done in two steps. 143 * via RCU. First step, marks device as down. That deletes 144 * all the timers and stops new packets from flowing through. 145 * 146 * Final cleanup doesn't occur until after all CPU's finished 147 * processing packets. 148 * 149 * Protected from multiple admin operations by RTNL mutex 150 */ 151 static void del_nbp(struct net_bridge_port *p) 152 { 153 struct net_bridge *br = p->br; 154 struct net_device *dev = p->dev; 155 156 sysfs_remove_link(&br->ifobj, dev->name); 157 158 dev_set_promiscuity(dev, -1); 159 160 cancel_delayed_work(&p->carrier_check); 161 162 spin_lock_bh(&br->lock); 163 br_stp_disable_port(p); 164 spin_unlock_bh(&br->lock); 165 166 br_fdb_delete_by_port(br, p); 167 168 list_del_rcu(&p->list); 169 170 rcu_assign_pointer(dev->br_port, NULL); 171 172 kobject_uevent(&p->kobj, KOBJ_REMOVE); 173 kobject_del(&p->kobj); 174 175 call_rcu(&p->rcu, destroy_nbp_rcu); 176 } 177 178 /* called with RTNL */ 179 static void del_br(struct net_bridge *br) 180 { 181 struct net_bridge_port *p, *n; 182 183 list_for_each_entry_safe(p, n, &br->port_list, list) { 184 del_nbp(p); 185 } 186 187 del_timer_sync(&br->gc_timer); 188 189 br_sysfs_delbr(br->dev); 190 unregister_netdevice(br->dev); 191 } 192 193 static struct net_device *new_bridge_dev(const char *name) 194 { 195 struct net_bridge *br; 196 struct net_device *dev; 197 198 dev = alloc_netdev(sizeof(struct net_bridge), name, 199 br_dev_setup); 200 201 if (!dev) 202 return NULL; 203 204 br = netdev_priv(dev); 205 br->dev = dev; 206 207 spin_lock_init(&br->lock); 208 INIT_LIST_HEAD(&br->port_list); 209 spin_lock_init(&br->hash_lock); 210 211 br->bridge_id.prio[0] = 0x80; 212 br->bridge_id.prio[1] = 0x00; 213 214 memcpy(br->group_addr, br_group_address, ETH_ALEN); 215 216 br->feature_mask = dev->features; 217 br->stp_enabled = 0; 218 br->designated_root = br->bridge_id; 219 br->root_path_cost = 0; 220 br->root_port = 0; 221 br->bridge_max_age = br->max_age = 20 * HZ; 222 br->bridge_hello_time = br->hello_time = 2 * HZ; 223 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 224 br->topology_change = 0; 225 br->topology_change_detected = 0; 226 br->ageing_time = 300 * HZ; 227 INIT_LIST_HEAD(&br->age_list); 228 229 br_stp_timer_init(br); 230 231 return dev; 232 } 233 234 /* find an available port number */ 235 static int find_portno(struct net_bridge *br) 236 { 237 int index; 238 struct net_bridge_port *p; 239 unsigned long *inuse; 240 241 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 242 GFP_KERNEL); 243 if (!inuse) 244 return -ENOMEM; 245 246 set_bit(0, inuse); /* zero is reserved */ 247 list_for_each_entry(p, &br->port_list, list) { 248 set_bit(p->port_no, inuse); 249 } 250 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 251 kfree(inuse); 252 253 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 254 } 255 256 /* called with RTNL but without bridge lock */ 257 static struct net_bridge_port *new_nbp(struct net_bridge *br, 258 struct net_device *dev) 259 { 260 int index; 261 struct net_bridge_port *p; 262 263 index = find_portno(br); 264 if (index < 0) 265 return ERR_PTR(index); 266 267 p = kzalloc(sizeof(*p), GFP_KERNEL); 268 if (p == NULL) 269 return ERR_PTR(-ENOMEM); 270 271 p->br = br; 272 dev_hold(dev); 273 p->dev = dev; 274 p->path_cost = port_cost(dev); 275 p->priority = 0x8000 >> BR_PORT_BITS; 276 p->port_no = index; 277 br_init_port(p); 278 p->state = BR_STATE_DISABLED; 279 INIT_WORK(&p->carrier_check, port_carrier_check, dev); 280 br_stp_port_timer_init(p); 281 282 kobject_init(&p->kobj); 283 kobject_set_name(&p->kobj, SYSFS_BRIDGE_PORT_ATTR); 284 p->kobj.ktype = &brport_ktype; 285 p->kobj.parent = &(dev->class_dev.kobj); 286 p->kobj.kset = NULL; 287 288 return p; 289 } 290 291 int br_add_bridge(const char *name) 292 { 293 struct net_device *dev; 294 int ret; 295 296 dev = new_bridge_dev(name); 297 if (!dev) 298 return -ENOMEM; 299 300 rtnl_lock(); 301 if (strchr(dev->name, '%')) { 302 ret = dev_alloc_name(dev, dev->name); 303 if (ret < 0) 304 goto err1; 305 } 306 307 ret = register_netdevice(dev); 308 if (ret) 309 goto err2; 310 311 /* network device kobject is not setup until 312 * after rtnl_unlock does it's hotplug magic. 313 * so hold reference to avoid race. 314 */ 315 dev_hold(dev); 316 rtnl_unlock(); 317 318 ret = br_sysfs_addbr(dev); 319 dev_put(dev); 320 321 if (ret) 322 unregister_netdev(dev); 323 out: 324 return ret; 325 326 err2: 327 free_netdev(dev); 328 err1: 329 rtnl_unlock(); 330 goto out; 331 } 332 333 int br_del_bridge(const char *name) 334 { 335 struct net_device *dev; 336 int ret = 0; 337 338 rtnl_lock(); 339 dev = __dev_get_by_name(name); 340 if (dev == NULL) 341 ret = -ENXIO; /* Could not find device */ 342 343 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 344 /* Attempt to delete non bridge device! */ 345 ret = -EPERM; 346 } 347 348 else if (dev->flags & IFF_UP) { 349 /* Not shutdown yet. */ 350 ret = -EBUSY; 351 } 352 353 else 354 del_br(netdev_priv(dev)); 355 356 rtnl_unlock(); 357 return ret; 358 } 359 360 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 361 int br_min_mtu(const struct net_bridge *br) 362 { 363 const struct net_bridge_port *p; 364 int mtu = 0; 365 366 ASSERT_RTNL(); 367 368 if (list_empty(&br->port_list)) 369 mtu = ETH_DATA_LEN; 370 else { 371 list_for_each_entry(p, &br->port_list, list) { 372 if (!mtu || p->dev->mtu < mtu) 373 mtu = p->dev->mtu; 374 } 375 } 376 return mtu; 377 } 378 379 /* 380 * Recomputes features using slave's features 381 */ 382 void br_features_recompute(struct net_bridge *br) 383 { 384 struct net_bridge_port *p; 385 unsigned long features, checksum; 386 387 features = br->feature_mask &~ NETIF_F_IP_CSUM; 388 checksum = br->feature_mask & NETIF_F_IP_CSUM; 389 390 list_for_each_entry(p, &br->port_list, list) { 391 if (!(p->dev->features 392 & (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM))) 393 checksum = 0; 394 features &= p->dev->features; 395 } 396 397 br->dev->features = features | checksum | NETIF_F_LLTX; 398 } 399 400 /* called with RTNL */ 401 int br_add_if(struct net_bridge *br, struct net_device *dev) 402 { 403 struct net_bridge_port *p; 404 int err = 0; 405 406 if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER) 407 return -EINVAL; 408 409 if (dev->hard_start_xmit == br_dev_xmit) 410 return -ELOOP; 411 412 if (dev->br_port != NULL) 413 return -EBUSY; 414 415 p = new_nbp(br, dev); 416 if (IS_ERR(p)) 417 return PTR_ERR(p); 418 419 err = kobject_add(&p->kobj); 420 if (err) 421 goto err0; 422 423 err = br_fdb_insert(br, p, dev->dev_addr); 424 if (err) 425 goto err1; 426 427 err = br_sysfs_addif(p); 428 if (err) 429 goto err2; 430 431 rcu_assign_pointer(dev->br_port, p); 432 dev_set_promiscuity(dev, 1); 433 434 list_add_rcu(&p->list, &br->port_list); 435 436 spin_lock_bh(&br->lock); 437 br_stp_recalculate_bridge_id(br); 438 br_features_recompute(br); 439 schedule_delayed_work(&p->carrier_check, BR_PORT_DEBOUNCE); 440 spin_unlock_bh(&br->lock); 441 442 dev_set_mtu(br->dev, br_min_mtu(br)); 443 kobject_uevent(&p->kobj, KOBJ_ADD); 444 445 return 0; 446 err2: 447 br_fdb_delete_by_port(br, p); 448 err1: 449 kobject_del(&p->kobj); 450 err0: 451 kobject_put(&p->kobj); 452 return err; 453 } 454 455 /* called with RTNL */ 456 int br_del_if(struct net_bridge *br, struct net_device *dev) 457 { 458 struct net_bridge_port *p = dev->br_port; 459 460 if (!p || p->br != br) 461 return -EINVAL; 462 463 del_nbp(p); 464 465 spin_lock_bh(&br->lock); 466 br_stp_recalculate_bridge_id(br); 467 br_features_recompute(br); 468 spin_unlock_bh(&br->lock); 469 470 return 0; 471 } 472 473 void __exit br_cleanup_bridges(void) 474 { 475 struct net_device *dev, *nxt; 476 477 rtnl_lock(); 478 for (dev = dev_base; dev; dev = nxt) { 479 nxt = dev->next; 480 if (dev->priv_flags & IFF_EBRIDGE) 481 del_br(dev->priv); 482 } 483 rtnl_unlock(); 484 485 } 486