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