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