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