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) 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(br->dev); 169 } 170 171 static struct net_device *new_bridge_dev(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; 181 182 br = netdev_priv(dev); 183 br->dev = dev; 184 185 spin_lock_init(&br->lock); 186 INIT_LIST_HEAD(&br->port_list); 187 spin_lock_init(&br->hash_lock); 188 189 br->bridge_id.prio[0] = 0x80; 190 br->bridge_id.prio[1] = 0x00; 191 192 memcpy(br->group_addr, br_group_address, ETH_ALEN); 193 194 br->feature_mask = dev->features; 195 br->stp_enabled = BR_NO_STP; 196 br->designated_root = br->bridge_id; 197 br->root_path_cost = 0; 198 br->root_port = 0; 199 br->bridge_max_age = br->max_age = 20 * HZ; 200 br->bridge_hello_time = br->hello_time = 2 * HZ; 201 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 202 br->topology_change = 0; 203 br->topology_change_detected = 0; 204 br->ageing_time = 300 * HZ; 205 206 br_netfilter_rtable_init(br); 207 208 INIT_LIST_HEAD(&br->age_list); 209 210 br_stp_timer_init(br); 211 212 return dev; 213 } 214 215 /* find an available port number */ 216 static int find_portno(struct net_bridge *br) 217 { 218 int index; 219 struct net_bridge_port *p; 220 unsigned long *inuse; 221 222 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 223 GFP_KERNEL); 224 if (!inuse) 225 return -ENOMEM; 226 227 set_bit(0, inuse); /* zero is reserved */ 228 list_for_each_entry(p, &br->port_list, list) { 229 set_bit(p->port_no, inuse); 230 } 231 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 232 kfree(inuse); 233 234 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 235 } 236 237 /* called with RTNL but without bridge lock */ 238 static struct net_bridge_port *new_nbp(struct net_bridge *br, 239 struct net_device *dev) 240 { 241 int index; 242 struct net_bridge_port *p; 243 244 index = find_portno(br); 245 if (index < 0) 246 return ERR_PTR(index); 247 248 p = kzalloc(sizeof(*p), GFP_KERNEL); 249 if (p == NULL) 250 return ERR_PTR(-ENOMEM); 251 252 p->br = br; 253 dev_hold(dev); 254 p->dev = dev; 255 p->path_cost = port_cost(dev); 256 p->priority = 0x8000 >> BR_PORT_BITS; 257 p->port_no = index; 258 br_init_port(p); 259 p->state = BR_STATE_DISABLED; 260 br_stp_port_timer_init(p); 261 262 return p; 263 } 264 265 int br_add_bridge(const char *name) 266 { 267 struct net_device *dev; 268 int ret; 269 270 dev = new_bridge_dev(name); 271 if (!dev) 272 return -ENOMEM; 273 274 rtnl_lock(); 275 if (strchr(dev->name, '%')) { 276 ret = dev_alloc_name(dev, dev->name); 277 if (ret < 0) 278 goto out_free; 279 } 280 281 ret = register_netdevice(dev); 282 if (ret) 283 goto out_free; 284 285 ret = br_sysfs_addbr(dev); 286 if (ret) 287 unregister_netdevice(dev); 288 out: 289 rtnl_unlock(); 290 return ret; 291 292 out_free: 293 free_netdev(dev); 294 goto out; 295 } 296 297 int br_del_bridge(const char *name) 298 { 299 struct net_device *dev; 300 int ret = 0; 301 302 rtnl_lock(); 303 dev = __dev_get_by_name(&init_net, name); 304 if (dev == NULL) 305 ret = -ENXIO; /* Could not find device */ 306 307 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 308 /* Attempt to delete non bridge device! */ 309 ret = -EPERM; 310 } 311 312 else if (dev->flags & IFF_UP) { 313 /* Not shutdown yet. */ 314 ret = -EBUSY; 315 } 316 317 else 318 del_br(netdev_priv(dev)); 319 320 rtnl_unlock(); 321 return ret; 322 } 323 324 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 325 int br_min_mtu(const struct net_bridge *br) 326 { 327 const struct net_bridge_port *p; 328 int mtu = 0; 329 330 ASSERT_RTNL(); 331 332 if (list_empty(&br->port_list)) 333 mtu = ETH_DATA_LEN; 334 else { 335 list_for_each_entry(p, &br->port_list, list) { 336 if (!mtu || p->dev->mtu < mtu) 337 mtu = p->dev->mtu; 338 } 339 } 340 return mtu; 341 } 342 343 /* 344 * Recomputes features using slave's features 345 */ 346 void br_features_recompute(struct net_bridge *br) 347 { 348 struct net_bridge_port *p; 349 unsigned long features; 350 351 features = br->feature_mask; 352 353 list_for_each_entry(p, &br->port_list, list) { 354 features = netdev_compute_features(features, p->dev->features); 355 } 356 357 br->dev->features = features; 358 } 359 360 /* called with RTNL */ 361 int br_add_if(struct net_bridge *br, struct net_device *dev) 362 { 363 struct net_bridge_port *p; 364 int err = 0; 365 366 if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER) 367 return -EINVAL; 368 369 if (dev->hard_start_xmit == br_dev_xmit) 370 return -ELOOP; 371 372 if (dev->br_port != NULL) 373 return -EBUSY; 374 375 p = new_nbp(br, dev); 376 if (IS_ERR(p)) 377 return PTR_ERR(p); 378 379 err = dev_set_promiscuity(dev, 1); 380 if (err) 381 goto put_back; 382 383 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 384 SYSFS_BRIDGE_PORT_ATTR); 385 if (err) 386 goto err0; 387 388 err = br_fdb_insert(br, p, dev->dev_addr); 389 if (err) 390 goto err1; 391 392 err = br_sysfs_addif(p); 393 if (err) 394 goto err2; 395 396 rcu_assign_pointer(dev->br_port, p); 397 dev_disable_lro(dev); 398 399 list_add_rcu(&p->list, &br->port_list); 400 401 spin_lock_bh(&br->lock); 402 br_stp_recalculate_bridge_id(br); 403 br_features_recompute(br); 404 405 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && 406 (br->dev->flags & IFF_UP)) 407 br_stp_enable_port(p); 408 spin_unlock_bh(&br->lock); 409 410 br_ifinfo_notify(RTM_NEWLINK, p); 411 412 dev_set_mtu(br->dev, br_min_mtu(br)); 413 414 kobject_uevent(&p->kobj, KOBJ_ADD); 415 416 return 0; 417 err2: 418 br_fdb_delete_by_port(br, p, 1); 419 err1: 420 kobject_del(&p->kobj); 421 err0: 422 kobject_put(&p->kobj); 423 dev_set_promiscuity(dev, -1); 424 put_back: 425 dev_put(dev); 426 kfree(p); 427 return err; 428 } 429 430 /* called with RTNL */ 431 int br_del_if(struct net_bridge *br, struct net_device *dev) 432 { 433 struct net_bridge_port *p = dev->br_port; 434 435 if (!p || p->br != br) 436 return -EINVAL; 437 438 del_nbp(p); 439 440 spin_lock_bh(&br->lock); 441 br_stp_recalculate_bridge_id(br); 442 br_features_recompute(br); 443 spin_unlock_bh(&br->lock); 444 445 return 0; 446 } 447 448 void __exit br_cleanup_bridges(void) 449 { 450 struct net_device *dev; 451 452 rtnl_lock(); 453 restart: 454 for_each_netdev(&init_net, dev) { 455 if (dev->priv_flags & IFF_EBRIDGE) { 456 del_br(dev->priv); 457 goto restart; 458 } 459 } 460 rtnl_unlock(); 461 462 } 463