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 * Since driver might sleep need to not be holding any locks. 33 */ 34 static int port_cost(struct net_device *dev) 35 { 36 if (dev->ethtool_ops && dev->ethtool_ops->get_settings) { 37 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, }; 38 39 if (!dev->ethtool_ops->get_settings(dev, &ecmd)) { 40 switch(ecmd.speed) { 41 case SPEED_10000: 42 return 2; 43 case SPEED_1000: 44 return 4; 45 case SPEED_100: 46 return 19; 47 case SPEED_10: 48 return 100; 49 } 50 } 51 } 52 53 /* Old silly heuristics based on name */ 54 if (!strncmp(dev->name, "lec", 3)) 55 return 7; 56 57 if (!strncmp(dev->name, "plip", 4)) 58 return 2500; 59 60 return 100; /* assume old 10Mbps */ 61 } 62 63 64 /* 65 * Check for port carrier transistions. 66 * Called from work queue to allow for calling functions that 67 * might sleep (such as speed check), and to debounce. 68 */ 69 void br_port_carrier_check(struct net_bridge_port *p) 70 { 71 struct net_device *dev = p->dev; 72 struct net_bridge *br = p->br; 73 74 if (netif_carrier_ok(dev)) 75 p->path_cost = port_cost(dev); 76 77 if (netif_running(br->dev)) { 78 spin_lock_bh(&br->lock); 79 if (netif_carrier_ok(dev)) { 80 if (p->state == BR_STATE_DISABLED) 81 br_stp_enable_port(p); 82 } else { 83 if (p->state != BR_STATE_DISABLED) 84 br_stp_disable_port(p); 85 } 86 spin_unlock_bh(&br->lock); 87 } 88 } 89 90 static void release_nbp(struct kobject *kobj) 91 { 92 struct net_bridge_port *p 93 = container_of(kobj, struct net_bridge_port, kobj); 94 kfree(p); 95 } 96 97 static struct kobj_type brport_ktype = { 98 #ifdef CONFIG_SYSFS 99 .sysfs_ops = &brport_sysfs_ops, 100 #endif 101 .release = release_nbp, 102 }; 103 104 static void destroy_nbp(struct net_bridge_port *p) 105 { 106 struct net_device *dev = p->dev; 107 108 p->br = NULL; 109 p->dev = NULL; 110 dev_put(dev); 111 112 kobject_put(&p->kobj); 113 } 114 115 static void destroy_nbp_rcu(struct rcu_head *head) 116 { 117 struct net_bridge_port *p = 118 container_of(head, struct net_bridge_port, rcu); 119 destroy_nbp(p); 120 } 121 122 /* Delete port(interface) from bridge is done in two steps. 123 * via RCU. First step, marks device as down. That deletes 124 * all the timers and stops new packets from flowing through. 125 * 126 * Final cleanup doesn't occur until after all CPU's finished 127 * processing packets. 128 * 129 * Protected from multiple admin operations by RTNL mutex 130 */ 131 static void del_nbp(struct net_bridge_port *p) 132 { 133 struct net_bridge *br = p->br; 134 struct net_device *dev = p->dev; 135 136 sysfs_remove_link(br->ifobj, dev->name); 137 138 dev_set_promiscuity(dev, -1); 139 140 spin_lock_bh(&br->lock); 141 br_stp_disable_port(p); 142 spin_unlock_bh(&br->lock); 143 144 br_ifinfo_notify(RTM_DELLINK, p); 145 146 br_fdb_delete_by_port(br, p, 1); 147 148 list_del_rcu(&p->list); 149 150 rcu_assign_pointer(dev->br_port, NULL); 151 152 kobject_uevent(&p->kobj, KOBJ_REMOVE); 153 kobject_del(&p->kobj); 154 155 call_rcu(&p->rcu, destroy_nbp_rcu); 156 } 157 158 /* called with RTNL */ 159 static void del_br(struct net_bridge *br) 160 { 161 struct net_bridge_port *p, *n; 162 163 list_for_each_entry_safe(p, n, &br->port_list, list) { 164 del_nbp(p); 165 } 166 167 del_timer_sync(&br->gc_timer); 168 169 br_sysfs_delbr(br->dev); 170 unregister_netdevice(br->dev); 171 } 172 173 static struct net_device *new_bridge_dev(const char *name) 174 { 175 struct net_bridge *br; 176 struct net_device *dev; 177 178 dev = alloc_netdev(sizeof(struct net_bridge), name, 179 br_dev_setup); 180 181 if (!dev) 182 return NULL; 183 184 br = netdev_priv(dev); 185 br->dev = dev; 186 187 spin_lock_init(&br->lock); 188 INIT_LIST_HEAD(&br->port_list); 189 spin_lock_init(&br->hash_lock); 190 191 br->bridge_id.prio[0] = 0x80; 192 br->bridge_id.prio[1] = 0x00; 193 194 memcpy(br->group_addr, br_group_address, ETH_ALEN); 195 196 br->feature_mask = dev->features; 197 br->stp_enabled = BR_NO_STP; 198 br->designated_root = br->bridge_id; 199 br->root_path_cost = 0; 200 br->root_port = 0; 201 br->bridge_max_age = br->max_age = 20 * HZ; 202 br->bridge_hello_time = br->hello_time = 2 * HZ; 203 br->bridge_forward_delay = br->forward_delay = 15 * HZ; 204 br->topology_change = 0; 205 br->topology_change_detected = 0; 206 br->ageing_time = 300 * HZ; 207 INIT_LIST_HEAD(&br->age_list); 208 209 br_stp_timer_init(br); 210 211 return dev; 212 } 213 214 /* find an available port number */ 215 static int find_portno(struct net_bridge *br) 216 { 217 int index; 218 struct net_bridge_port *p; 219 unsigned long *inuse; 220 221 inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long), 222 GFP_KERNEL); 223 if (!inuse) 224 return -ENOMEM; 225 226 set_bit(0, inuse); /* zero is reserved */ 227 list_for_each_entry(p, &br->port_list, list) { 228 set_bit(p->port_no, inuse); 229 } 230 index = find_first_zero_bit(inuse, BR_MAX_PORTS); 231 kfree(inuse); 232 233 return (index >= BR_MAX_PORTS) ? -EXFULL : index; 234 } 235 236 /* called with RTNL but without bridge lock */ 237 static struct net_bridge_port *new_nbp(struct net_bridge *br, 238 struct net_device *dev) 239 { 240 int index; 241 struct net_bridge_port *p; 242 243 index = find_portno(br); 244 if (index < 0) 245 return ERR_PTR(index); 246 247 p = kzalloc(sizeof(*p), GFP_KERNEL); 248 if (p == NULL) 249 return ERR_PTR(-ENOMEM); 250 251 p->br = br; 252 dev_hold(dev); 253 p->dev = dev; 254 p->path_cost = port_cost(dev); 255 p->priority = 0x8000 >> BR_PORT_BITS; 256 p->port_no = index; 257 br_init_port(p); 258 p->state = BR_STATE_DISABLED; 259 br_stp_port_timer_init(p); 260 261 return p; 262 } 263 264 int br_add_bridge(const char *name) 265 { 266 struct net_device *dev; 267 int ret; 268 269 dev = new_bridge_dev(name); 270 if (!dev) 271 return -ENOMEM; 272 273 rtnl_lock(); 274 if (strchr(dev->name, '%')) { 275 ret = dev_alloc_name(dev, dev->name); 276 if (ret < 0) 277 goto out_free; 278 } 279 280 ret = register_netdevice(dev); 281 if (ret) 282 goto out_free; 283 284 ret = br_sysfs_addbr(dev); 285 if (ret) 286 unregister_netdevice(dev); 287 out: 288 rtnl_unlock(); 289 return ret; 290 291 out_free: 292 free_netdev(dev); 293 goto out; 294 } 295 296 int br_del_bridge(const char *name) 297 { 298 struct net_device *dev; 299 int ret = 0; 300 301 rtnl_lock(); 302 dev = __dev_get_by_name(&init_net, name); 303 if (dev == NULL) 304 ret = -ENXIO; /* Could not find device */ 305 306 else if (!(dev->priv_flags & IFF_EBRIDGE)) { 307 /* Attempt to delete non bridge device! */ 308 ret = -EPERM; 309 } 310 311 else if (dev->flags & IFF_UP) { 312 /* Not shutdown yet. */ 313 ret = -EBUSY; 314 } 315 316 else 317 del_br(netdev_priv(dev)); 318 319 rtnl_unlock(); 320 return ret; 321 } 322 323 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */ 324 int br_min_mtu(const struct net_bridge *br) 325 { 326 const struct net_bridge_port *p; 327 int mtu = 0; 328 329 ASSERT_RTNL(); 330 331 if (list_empty(&br->port_list)) 332 mtu = ETH_DATA_LEN; 333 else { 334 list_for_each_entry(p, &br->port_list, list) { 335 if (!mtu || p->dev->mtu < mtu) 336 mtu = p->dev->mtu; 337 } 338 } 339 return mtu; 340 } 341 342 /* 343 * Recomputes features using slave's features 344 */ 345 void br_features_recompute(struct net_bridge *br) 346 { 347 struct net_bridge_port *p; 348 unsigned long features; 349 350 features = br->feature_mask; 351 352 list_for_each_entry(p, &br->port_list, list) { 353 features = netdev_compute_features(features, p->dev->features); 354 } 355 356 br->dev->features = features; 357 } 358 359 /* called with RTNL */ 360 int br_add_if(struct net_bridge *br, struct net_device *dev) 361 { 362 struct net_bridge_port *p; 363 int err = 0; 364 365 if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER) 366 return -EINVAL; 367 368 if (dev->hard_start_xmit == br_dev_xmit) 369 return -ELOOP; 370 371 if (dev->br_port != NULL) 372 return -EBUSY; 373 374 p = new_nbp(br, dev); 375 if (IS_ERR(p)) 376 return PTR_ERR(p); 377 378 err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj), 379 SYSFS_BRIDGE_PORT_ATTR); 380 if (err) 381 goto err0; 382 383 err = br_fdb_insert(br, p, dev->dev_addr); 384 if (err) 385 goto err1; 386 387 err = br_sysfs_addif(p); 388 if (err) 389 goto err2; 390 391 rcu_assign_pointer(dev->br_port, p); 392 dev_set_promiscuity(dev, 1); 393 394 list_add_rcu(&p->list, &br->port_list); 395 396 spin_lock_bh(&br->lock); 397 br_stp_recalculate_bridge_id(br); 398 br_features_recompute(br); 399 400 if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) && 401 (br->dev->flags & IFF_UP)) 402 br_stp_enable_port(p); 403 spin_unlock_bh(&br->lock); 404 405 br_ifinfo_notify(RTM_NEWLINK, p); 406 407 dev_set_mtu(br->dev, br_min_mtu(br)); 408 409 kobject_uevent(&p->kobj, KOBJ_ADD); 410 411 return 0; 412 err2: 413 br_fdb_delete_by_port(br, p, 1); 414 err1: 415 kobject_del(&p->kobj); 416 goto put_back; 417 err0: 418 kobject_put(&p->kobj); 419 420 put_back: 421 dev_put(dev); 422 return err; 423 } 424 425 /* called with RTNL */ 426 int br_del_if(struct net_bridge *br, struct net_device *dev) 427 { 428 struct net_bridge_port *p = dev->br_port; 429 430 if (!p || p->br != br) 431 return -EINVAL; 432 433 del_nbp(p); 434 435 spin_lock_bh(&br->lock); 436 br_stp_recalculate_bridge_id(br); 437 br_features_recompute(br); 438 spin_unlock_bh(&br->lock); 439 440 return 0; 441 } 442 443 void __exit br_cleanup_bridges(void) 444 { 445 struct net_device *dev, *nxt; 446 447 rtnl_lock(); 448 for_each_netdev_safe(&init_net, dev, nxt) 449 if (dev->priv_flags & IFF_EBRIDGE) 450 del_br(dev->priv); 451 rtnl_unlock(); 452 453 } 454