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(struct work_struct *work) 81 { 82 struct net_bridge_port *p; 83 struct net_device *dev; 84 struct net_bridge *br; 85 86 dev = container_of(work, struct net_bridge_port, 87 carrier_check.work)->dev; 88 work_release(work); 89 90 rtnl_lock(); 91 p = dev->br_port; 92 if (!p) 93 goto done; 94 br = p->br; 95 96 if (netif_carrier_ok(dev)) 97 p->path_cost = port_cost(dev); 98 99 if (br->dev->flags & IFF_UP) { 100 spin_lock_bh(&br->lock); 101 if (netif_carrier_ok(dev)) { 102 if (p->state == BR_STATE_DISABLED) 103 br_stp_enable_port(p); 104 } else { 105 if (p->state != BR_STATE_DISABLED) 106 br_stp_disable_port(p); 107 } 108 spin_unlock_bh(&br->lock); 109 } 110 done: 111 dev_put(dev); 112 rtnl_unlock(); 113 } 114 115 static void release_nbp(struct kobject *kobj) 116 { 117 struct net_bridge_port *p 118 = container_of(kobj, struct net_bridge_port, kobj); 119 kfree(p); 120 } 121 122 static struct kobj_type brport_ktype = { 123 #ifdef CONFIG_SYSFS 124 .sysfs_ops = &brport_sysfs_ops, 125 #endif 126 .release = release_nbp, 127 }; 128 129 static void destroy_nbp(struct net_bridge_port *p) 130 { 131 struct net_device *dev = p->dev; 132 133 p->br = NULL; 134 p->dev = NULL; 135 dev_put(dev); 136 137 kobject_put(&p->kobj); 138 } 139 140 static void destroy_nbp_rcu(struct rcu_head *head) 141 { 142 struct net_bridge_port *p = 143 container_of(head, struct net_bridge_port, rcu); 144 destroy_nbp(p); 145 } 146 147 /* Delete port(interface) from bridge is done in two steps. 148 * via RCU. First step, marks device as down. That deletes 149 * all the timers and stops new packets from flowing through. 150 * 151 * Final cleanup doesn't occur until after all CPU's finished 152 * processing packets. 153 * 154 * Protected from multiple admin operations by RTNL mutex 155 */ 156 static void del_nbp(struct net_bridge_port *p) 157 { 158 struct net_bridge *br = p->br; 159 struct net_device *dev = p->dev; 160 161 sysfs_remove_link(&br->ifobj, dev->name); 162 163 dev_set_promiscuity(dev, -1); 164 165 if (cancel_delayed_work(&p->carrier_check)) 166 dev_put(dev); 167 168 spin_lock_bh(&br->lock); 169 br_stp_disable_port(p); 170 spin_unlock_bh(&br->lock); 171 172 br_fdb_delete_by_port(br, p, 1); 173 174 list_del_rcu(&p->list); 175 176 rcu_assign_pointer(dev->br_port, NULL); 177 178 kobject_uevent(&p->kobj, KOBJ_REMOVE); 179 kobject_del(&p->kobj); 180 181 call_rcu(&p->rcu, destroy_nbp_rcu); 182 } 183 184 /* called with RTNL */ 185 static void del_br(struct net_bridge *br) 186 { 187 struct net_bridge_port *p, *n; 188 189 list_for_each_entry_safe(p, n, &br->port_list, list) { 190 del_nbp(p); 191 } 192 193 del_timer_sync(&br->gc_timer); 194 195 br_sysfs_delbr(br->dev); 196 unregister_netdevice(br->dev); 197 } 198 199 static struct net_device *new_bridge_dev(const char *name) 200 { 201 struct net_bridge *br; 202 struct net_device *dev; 203 204 dev = alloc_netdev(sizeof(struct net_bridge), name, 205 br_dev_setup); 206 207 if (!dev) 208 return NULL; 209 210 br = netdev_priv(dev); 211 br->dev = dev; 212 213 spin_lock_init(&br->lock); 214 INIT_LIST_HEAD(&br->port_list); 215 spin_lock_init(&br->hash_lock); 216 217 br->bridge_id.prio[0] = 0x80; 218 br->bridge_id.prio[1] = 0x00; 219 220 memcpy(br->group_addr, br_group_address, ETH_ALEN); 221 222 br->feature_mask = dev->features; 223 br->stp_enabled = 0; 224 br->designated_root = br->bridge_id; 225 br->root_path_cost = 0; 226 br->root_port = 0; 227 br->bridge_max_age = br->max_age = 20 * HZ; 228 br->bridge_hello_time = br->hello_time = 2 * HZ; 229 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 230 br->topology_change = 0; 231 br->topology_change_detected = 0; 232 br->ageing_time = 300 * HZ; 233 INIT_LIST_HEAD(&br->age_list); 234 235 br_stp_timer_init(br); 236 237 return dev; 238 } 239 240 /* find an available port number */ 241 static int find_portno(struct net_bridge *br) 242 { 243 int index; 244 struct net_bridge_port *p; 245 unsigned long *inuse; 246 247 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 248 GFP_KERNEL); 249 if (!inuse) 250 return -ENOMEM; 251 252 set_bit(0, inuse); /* zero is reserved */ 253 list_for_each_entry(p, &br->port_list, list) { 254 set_bit(p->port_no, inuse); 255 } 256 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 257 kfree(inuse); 258 259 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 260 } 261 262 /* called with RTNL but without bridge lock */ 263 static struct net_bridge_port *new_nbp(struct net_bridge *br, 264 struct net_device *dev) 265 { 266 int index; 267 struct net_bridge_port *p; 268 269 index = find_portno(br); 270 if (index < 0) 271 return ERR_PTR(index); 272 273 p = kzalloc(sizeof(*p), GFP_KERNEL); 274 if (p == NULL) 275 return ERR_PTR(-ENOMEM); 276 277 p->br = br; 278 dev_hold(dev); 279 p->dev = dev; 280 p->path_cost = port_cost(dev); 281 p->priority = 0x8000 >> BR_PORT_BITS; 282 p->port_no = index; 283 br_init_port(p); 284 p->state = BR_STATE_DISABLED; 285 INIT_DELAYED_WORK_NAR(&p->carrier_check, port_carrier_check); 286 br_stp_port_timer_init(p); 287 288 kobject_init(&p->kobj); 289 kobject_set_name(&p->kobj, SYSFS_BRIDGE_PORT_ATTR); 290 p->kobj.ktype = &brport_ktype; 291 p->kobj.parent = &(dev->dev.kobj); 292 p->kobj.kset = NULL; 293 294 return p; 295 } 296 297 int br_add_bridge(const char *name) 298 { 299 struct net_device *dev; 300 int ret; 301 302 dev = new_bridge_dev(name); 303 if (!dev) 304 return -ENOMEM; 305 306 rtnl_lock(); 307 if (strchr(dev->name, '%')) { 308 ret = dev_alloc_name(dev, dev->name); 309 if (ret < 0) { 310 free_netdev(dev); 311 goto out; 312 } 313 } 314 315 ret = register_netdevice(dev); 316 if (ret) 317 goto out; 318 319 ret = br_sysfs_addbr(dev); 320 if (ret) 321 unregister_netdevice(dev); 322 out: 323 rtnl_unlock(); 324 return ret; 325 } 326 327 int br_del_bridge(const char *name) 328 { 329 struct net_device *dev; 330 int ret = 0; 331 332 rtnl_lock(); 333 dev = __dev_get_by_name(name); 334 if (dev == NULL) 335 ret = -ENXIO; /* Could not find device */ 336 337 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 338 /* Attempt to delete non bridge device! */ 339 ret = -EPERM; 340 } 341 342 else if (dev->flags & IFF_UP) { 343 /* Not shutdown yet. */ 344 ret = -EBUSY; 345 } 346 347 else 348 del_br(netdev_priv(dev)); 349 350 rtnl_unlock(); 351 return ret; 352 } 353 354 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 355 int br_min_mtu(const struct net_bridge *br) 356 { 357 const struct net_bridge_port *p; 358 int mtu = 0; 359 360 ASSERT_RTNL(); 361 362 if (list_empty(&br->port_list)) 363 mtu = ETH_DATA_LEN; 364 else { 365 list_for_each_entry(p, &br->port_list, list) { 366 if (!mtu || p->dev->mtu < mtu) 367 mtu = p->dev->mtu; 368 } 369 } 370 return mtu; 371 } 372 373 /* 374 * Recomputes features using slave's features 375 */ 376 void br_features_recompute(struct net_bridge *br) 377 { 378 struct net_bridge_port *p; 379 unsigned long features, checksum; 380 381 checksum = br->feature_mask & NETIF_F_ALL_CSUM ? NETIF_F_NO_CSUM : 0; 382 features = br->feature_mask & ~NETIF_F_ALL_CSUM; 383 384 list_for_each_entry(p, &br->port_list, list) { 385 unsigned long feature = p->dev->features; 386 387 if (checksum & NETIF_F_NO_CSUM && !(feature & NETIF_F_NO_CSUM)) 388 checksum ^= NETIF_F_NO_CSUM | NETIF_F_HW_CSUM; 389 if (checksum & NETIF_F_HW_CSUM && !(feature & NETIF_F_HW_CSUM)) 390 checksum ^= NETIF_F_HW_CSUM | NETIF_F_IP_CSUM; 391 if (!(feature & NETIF_F_IP_CSUM)) 392 checksum = 0; 393 394 if (feature & NETIF_F_GSO) 395 feature |= NETIF_F_GSO_SOFTWARE; 396 feature |= NETIF_F_GSO; 397 398 features &= feature; 399 } 400 401 if (!(checksum & NETIF_F_ALL_CSUM)) 402 features &= ~NETIF_F_SG; 403 if (!(features & NETIF_F_SG)) 404 features &= ~NETIF_F_GSO_MASK; 405 406 br->dev->features = features | checksum | NETIF_F_LLTX | 407 NETIF_F_GSO_ROBUST; 408 } 409 410 /* called with RTNL */ 411 int br_add_if(struct net_bridge *br, struct net_device *dev) 412 { 413 struct net_bridge_port *p; 414 int err = 0; 415 416 if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER) 417 return -EINVAL; 418 419 if (dev->hard_start_xmit == br_dev_xmit) 420 return -ELOOP; 421 422 if (dev->br_port != NULL) 423 return -EBUSY; 424 425 p = new_nbp(br, dev); 426 if (IS_ERR(p)) 427 return PTR_ERR(p); 428 429 err = kobject_add(&p->kobj); 430 if (err) 431 goto err0; 432 433 err = br_fdb_insert(br, p, dev->dev_addr); 434 if (err) 435 goto err1; 436 437 err = br_sysfs_addif(p); 438 if (err) 439 goto err2; 440 441 rcu_assign_pointer(dev->br_port, p); 442 dev_set_promiscuity(dev, 1); 443 444 list_add_rcu(&p->list, &br->port_list); 445 446 spin_lock_bh(&br->lock); 447 br_stp_recalculate_bridge_id(br); 448 br_features_recompute(br); 449 if (schedule_delayed_work(&p->carrier_check, BR_PORT_DEBOUNCE)) 450 dev_hold(dev); 451 452 spin_unlock_bh(&br->lock); 453 454 dev_set_mtu(br->dev, br_min_mtu(br)); 455 kobject_uevent(&p->kobj, KOBJ_ADD); 456 457 return 0; 458 err2: 459 br_fdb_delete_by_port(br, p, 1); 460 err1: 461 kobject_del(&p->kobj); 462 err0: 463 kobject_put(&p->kobj); 464 return err; 465 } 466 467 /* called with RTNL */ 468 int br_del_if(struct net_bridge *br, struct net_device *dev) 469 { 470 struct net_bridge_port *p = dev->br_port; 471 472 if (!p || p->br != br) 473 return -EINVAL; 474 475 del_nbp(p); 476 477 spin_lock_bh(&br->lock); 478 br_stp_recalculate_bridge_id(br); 479 br_features_recompute(br); 480 spin_unlock_bh(&br->lock); 481 482 return 0; 483 } 484 485 void __exit br_cleanup_bridges(void) 486 { 487 struct net_device *dev, *nxt; 488 489 rtnl_lock(); 490 for (dev = dev_base; dev; dev = nxt) { 491 nxt = dev->next; 492 if (dev->priv_flags & IFF_EBRIDGE) 493 del_br(dev->priv); 494 } 495 rtnl_unlock(); 496 497 } 498