release/src-rt-6.x.4708/linux/linux-2.6.36/net/bridge/br_if.c

   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/netpoll.h>
  17 #include <linux/ethtool.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/rtnetlink.h>
  22 #include <linux/if_ether.h>
  23 #include <linux/slab.h>
  24 #include <net/sock.h>
  25
  26 #include "br_private.h"
  27
  28 #ifdef HNDCTF
  29 #include <ctf/hndctf.h>
  30 #endif /* HNDCTF */
  31
  32 /*
  33  * Determine initial path cost based on speed.
  34  * using recommendations from 802.1d standard
  35  *
  36  * Since driver might sleep need to not be holding any locks.
  37  */
  38 static int port_cost(struct net_device *dev)
  39 {
  40         if (dev->ethtool_ops && dev->ethtool_ops->get_settings) {
  41                 struct ethtool_cmd ecmd = { .cmd = ETHTOOL_GSET, };
  42
  43                 if (!dev->ethtool_ops->get_settings(dev, &ecmd)) {
  44                         switch(ecmd.speed) {
  45                         case SPEED_10000:
  46                                 return 2;
  47                         case SPEED_1000:
  48                                 return 4;
  49                         case SPEED_100:
  50                                 return 19;
  51                         case SPEED_10:
  52                                 return 100;
  53                         }
  54                 }
  55         }
  56
  57         /* Old silly heuristics based on name */
  58         if (!strncmp(dev->name, "lec", 3))
  59                 return 7;
  60
  61         if (!strncmp(dev->name, "plip", 4))
  62                 return 2500;
  63
  64         return 100;     /* assume old 10Mbps */
  65 }
  66
  67
  68 /*
  69  * Check for port carrier transistions.
  70  * Called from work queue to allow for calling functions that
  71  * might sleep (such as speed check), and to debounce.
  72  */
  73 void br_port_carrier_check(struct net_bridge_port *p)
  74 {
  75         struct net_device *dev = p->dev;
  76         struct net_bridge *br = p->br;
  77
  78         if (netif_carrier_ok(dev))
  79                 p->path_cost = port_cost(dev);
  80
  81         if (netif_running(br->dev)) {
  82                 spin_lock_bh(&br->lock);
  83                 if (netif_carrier_ok(dev)) {
  84                         if (p->state == BR_STATE_DISABLED)
  85                                 br_stp_enable_port(p);
  86                 } else {
  87                         if (p->state != BR_STATE_DISABLED)
  88                                 br_stp_disable_port(p);
  89                 }
  90                 spin_unlock_bh(&br->lock);
  91         }
  92 }
  93
  94 static void release_nbp(struct kobject *kobj)
  95 {
  96         struct net_bridge_port *p
  97                 = container_of(kobj, struct net_bridge_port, kobj);
  98         kfree(p);
  99 }
 100
 101 static struct kobj_type brport_ktype = {
 102 #ifdef CONFIG_SYSFS
 103         .sysfs_ops = &brport_sysfs_ops,
 104 #endif
 105         .release = release_nbp,
 106 };
 107
 108 static void destroy_nbp(struct net_bridge_port *p)
 109 {
 110         struct net_device *dev = p->dev;
 111
 112         p->br = NULL;
 113         p->dev = NULL;
 114         dev_put(dev);
 115
 116         kobject_put(&p->kobj);
 117 }
 118
 119 static void destroy_nbp_rcu(struct rcu_head *head)
 120 {
 121         struct net_bridge_port *p =
 122                         container_of(head, struct net_bridge_port, rcu);
 123         destroy_nbp(p);
 124 }
 125
 126 /* Delete port(interface) from bridge is done in two steps.
 127  * via RCU. First step, marks device as down. That deletes
 128  * all the timers and stops new packets from flowing through.
 129  *
 130  * Final cleanup doesn't occur until after all CPU's finished
 131  * processing packets.
 132  *
 133  * Protected from multiple admin operations by RTNL mutex
 134  */
 135 static void del_nbp(struct net_bridge_port *p)
 136 {
 137         struct net_bridge *br = p->br;
 138         struct net_device *dev = p->dev;
 139
 140         sysfs_remove_link(br->ifobj, p->dev->name);
 141
 142         dev_set_promiscuity(dev, -1);
 143
 144         spin_lock_bh(&br->lock);
 145         br_stp_disable_port(p);
 146         spin_unlock_bh(&br->lock);
 147
 148         br_ifinfo_notify(RTM_DELLINK, p);
 149
 150         br_fdb_delete_by_port(br, p, 1);
 151
 152         list_del_rcu(&p->list);
 153
 154         dev->priv_flags &= ~IFF_BRIDGE_PORT;
 155
 156         netdev_rx_handler_unregister(dev);
 157
 158         br_multicast_del_port(p);
 159
 160         kobject_uevent(&p->kobj, KOBJ_REMOVE);
 161         kobject_del(&p->kobj);
 162
 163         br_netpoll_disable(p);
 164
 165         call_rcu(&p->rcu, destroy_nbp_rcu);
 166 }
 167
 168 /* called with RTNL */
 169 static void del_br(struct net_bridge *br, struct list_head *head)
 170 {
 171         struct net_bridge_port *p, *n;
 172
 173         list_for_each_entry_safe(p, n, &br->port_list, list) {
 174                 del_nbp(p);
 175         }
 176
 177         del_timer_sync(&br->gc_timer);
 178
 179         br_sysfs_delbr(br->dev);
 180         unregister_netdevice_queue(br->dev, head);
 181 }
 182
 183 static struct net_device *new_bridge_dev(struct net *net, const char *name)
 184 {
 185         struct net_bridge *br;
 186         struct net_device *dev;
 187
 188         dev = alloc_netdev(sizeof(struct net_bridge), name,
 189                            br_dev_setup);
 190
 191         if (!dev)
 192                 return NULL;
 193         dev_net_set(dev, net);
 194
 195         br = netdev_priv(dev);
 196         br->dev = dev;
 197
 198         br->stats = alloc_percpu(struct br_cpu_netstats);
 199         if (!br->stats) {
 200                 free_netdev(dev);
 201                 return NULL;
 202         }
 203
 204         spin_lock_init(&br->lock);
 205         INIT_LIST_HEAD(&br->port_list);
 206         spin_lock_init(&br->hash_lock);
 207
 208         br->bridge_id.prio[0] = 0x80;
 209         br->bridge_id.prio[1] = 0x00;
 210
 211         memcpy(br->group_addr, br_group_address, ETH_ALEN);
 212
 213         br->feature_mask = dev->features;
 214         br->stp_enabled = BR_NO_STP;
 215         br->designated_root = br->bridge_id;
 216         br->root_path_cost = 0;
 217         br->root_port = 0;
 218         br->bridge_max_age = br->max_age = 20 * HZ;
 219         br->bridge_hello_time = br->hello_time = 2 * HZ;
 220         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 221         br->topology_change = 0;
 222         br->topology_change_detected = 0;
 223         br->ageing_time = 300 * HZ;
 224
 225         br_netfilter_rtable_init(br);
 226
 227         br_stp_timer_init(br);
 228         br_multicast_init(br);
 229
 230         return dev;
 231 }
 232
 233 /* find an available port number */
 234 static int find_portno(struct net_bridge *br)
 235 {
 236         int index;
 237         struct net_bridge_port *p;
 238         unsigned long *inuse;
 239
 240         inuse = kcalloc(BITS_TO_LONGS(BR_MAX_PORTS), sizeof(unsigned long),
 241                         GFP_KERNEL);
 242         if (!inuse)
 243                 return -ENOMEM;
 244
 245         set_bit(0, inuse);      /* zero is reserved */
 246         list_for_each_entry(p, &br->port_list, list) {
 247                 set_bit(p->port_no, inuse);
 248         }
 249         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 250         kfree(inuse);
 251
 252         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 253 }
 254
 255 /* called with RTNL but without bridge lock */
 256 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 257                                        struct net_device *dev)
 258 {
 259         int index;
 260         struct net_bridge_port *p;
 261
 262         index = find_portno(br);
 263         if (index < 0)
 264                 return ERR_PTR(index);
 265
 266         p = kzalloc(sizeof(*p), GFP_KERNEL);
 267         if (p == NULL)
 268                 return ERR_PTR(-ENOMEM);
 269
 270         p->br = br;
 271         dev_hold(dev);
 272         p->dev = dev;
 273         p->path_cost = port_cost(dev);
 274         p->priority = 0x8000 >> BR_PORT_BITS;
 275         p->port_no = index;
 276         p->flags = 0;
 277         br_init_port(p);
 278         p->state = BR_STATE_DISABLED;
 279         br_stp_port_timer_init(p);
 280         br_multicast_add_port(p);
 281
 282         return p;
 283 }
 284
 285 static struct device_type br_type = {
 286         .name   = "bridge",
 287 };
 288
 289 int br_add_bridge(struct net *net, const char *name)
 290 {
 291         struct net_device *dev;
 292         int ret;
 293
 294         dev = new_bridge_dev(net, name);
 295         if (!dev)
 296                 return -ENOMEM;
 297
 298         rtnl_lock();
 299         if (strchr(dev->name, '%')) {
 300                 ret = dev_alloc_name(dev, dev->name);
 301                 if (ret < 0)
 302                         goto out_free;
 303         }
 304
 305         SET_NETDEV_DEVTYPE(dev, &br_type);
 306
 307         ret = register_netdevice(dev);
 308         if (ret)
 309                 goto out_free;
 310
 311 #ifdef HNDCTF
 312         if ((ctf_dev_register(kcih, dev, TRUE) != BCME_OK) ||
 313             (ctf_enable(kcih, dev, TRUE, NULL) != BCME_OK)) {
 314                 ctf_dev_unregister(kcih, dev);
 315                 unregister_netdevice(dev);
 316                 ret = -ENXIO;
 317                 goto out_free;
 318         }
 319 #endif /* HNDCTF */
 320
 321         ret = br_sysfs_addbr(dev);
 322         if (ret)
 323                 unregister_netdevice(dev);
 324  out:
 325         rtnl_unlock();
 326         return ret;
 327
 328 out_free:
 329         free_netdev(dev);
 330         goto out;
 331 }
 332
 333 int br_del_bridge(struct net *net, const char *name)
 334 {
 335         struct net_device *dev;
 336         int ret = 0;
 337
 338         rtnl_lock();
 339         dev = __dev_get_by_name(net, name);
 340         if (dev == NULL)
 341                 ret =  -ENXIO;  /* Could not find device */
 342
 343         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 344                 /* Attempt to delete non bridge device! */
 345                 ret = -EPERM;
 346         }
 347
 348         else if (dev->flags & IFF_UP) {
 349                 /* Not shutdown yet. */
 350                 ret = -EBUSY;
 351         }
 352
 353         else {
 354 #ifdef HNDCTF
 355                 ctf_dev_unregister(kcih, dev);
 356 #endif /* HNDCTF */
 357                 del_br(netdev_priv(dev), NULL);
 358         }
 359
 360         rtnl_unlock();
 361         return ret;
 362 }
 363
 364 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
 365 int br_min_mtu(const struct net_bridge *br)
 366 {
 367         const struct net_bridge_port *p;
 368         int mtu = 0;
 369
 370         ASSERT_RTNL();
 371
 372         if (list_empty(&br->port_list))
 373                 mtu = ETH_DATA_LEN;
 374         else {
 375                 list_for_each_entry(p, &br->port_list, list) {
 376                         if (!mtu  || p->dev->mtu < mtu)
 377                                 mtu = p->dev->mtu;
 378                 }
 379         }
 380         return mtu;
 381 }
 382
 383 /*
 384  * Recomputes features using slave's features
 385  */
 386 void br_features_recompute(struct net_bridge *br)
 387 {
 388         struct net_bridge_port *p;
 389         unsigned long features, mask;
 390
 391         features = mask = br->feature_mask;
 392         if (list_empty(&br->port_list))
 393                 goto done;
 394
 395         features &= ~NETIF_F_ONE_FOR_ALL;
 396
 397         list_for_each_entry(p, &br->port_list, list) {
 398                 features = netdev_increment_features(features,
 399                                                      p->dev->features, mask);
 400         }
 401
 402 done:
 403         br->dev->features = netdev_fix_features(features, NULL);
 404 }
 405
 406 /* called with RTNL */
 407 int br_add_if(struct net_bridge *br, struct net_device *dev)
 408 {
 409         struct net_bridge_port *p;
 410         int err = 0;
 411
 412         /* Don't allow bridging non-ethernet like devices */
 413         if ((dev->flags & IFF_LOOPBACK) ||
 414             dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN)
 415                 return -EINVAL;
 416
 417         /* No bridging of bridges */
 418         if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit)
 419                 return -ELOOP;
 420
 421         /* Device is already being bridged */
 422         if (br_port_exists(dev))
 423                 return -EBUSY;
 424
 425         /* No bridging devices that dislike that (e.g. wireless) */
 426         if (dev->priv_flags & IFF_DONT_BRIDGE)
 427                 return -EOPNOTSUPP;
 428
 429         p = new_nbp(br, dev);
 430         if (IS_ERR(p))
 431                 return PTR_ERR(p);
 432
 433         err = dev_set_promiscuity(dev, 1);
 434         if (err)
 435                 goto put_back;
 436
 437         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 438                                    SYSFS_BRIDGE_PORT_ATTR);
 439         if (err)
 440                 goto err0;
 441
 442         err = br_fdb_insert(br, p, dev->dev_addr);
 443         if (err)
 444                 goto err1;
 445
 446         err = br_sysfs_addif(p);
 447         if (err)
 448                 goto err2;
 449
 450         if (br_netpoll_info(br) && ((err = br_netpoll_enable(p))))
 451                 goto err3;
 452
 453         err = netdev_rx_handler_register(dev, br_handle_frame, p);
 454         if (err)
 455                 goto err3;
 456
 457         dev->priv_flags |= IFF_BRIDGE_PORT;
 458
 459         dev_disable_lro(dev);
 460
 461         list_add_rcu(&p->list, &br->port_list);
 462
 463         spin_lock_bh(&br->lock);
 464         br_stp_recalculate_bridge_id(br);
 465         br_features_recompute(br);
 466
 467         if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
 468             (br->dev->flags & IFF_UP))
 469                 br_stp_enable_port(p);
 470         spin_unlock_bh(&br->lock);
 471
 472         br_ifinfo_notify(RTM_NEWLINK, p);
 473
 474         dev_set_mtu(br->dev, br_min_mtu(br));
 475
 476         kobject_uevent(&p->kobj, KOBJ_ADD);
 477
 478         return 0;
 479 err3:
 480         sysfs_remove_link(br->ifobj, p->dev->name);
 481 err2:
 482         br_fdb_delete_by_port(br, p, 1);
 483 err1:
 484         kobject_put(&p->kobj);
 485         p = NULL; /* kobject_put frees */
 486 err0:
 487         dev_set_promiscuity(dev, -1);
 488 put_back:
 489         dev_put(dev);
 490         kfree(p);
 491         return err;
 492 }
 493
 494 /* called with RTNL */
 495 int br_del_if(struct net_bridge *br, struct net_device *dev)
 496 {
 497         struct net_bridge_port *p;
 498
 499         if (!br_port_exists(dev))
 500                 return -EINVAL;
 501
 502         p = br_port_get(dev);
 503         if (p->br != br)
 504                 return -EINVAL;
 505
 506         del_nbp(p);
 507
 508         spin_lock_bh(&br->lock);
 509         br_stp_recalculate_bridge_id(br);
 510         br_features_recompute(br);
 511         spin_unlock_bh(&br->lock);
 512
 513         return 0;
 514 }
 515
 516 void __net_exit br_net_exit(struct net *net)
 517 {
 518         struct net_device *dev;
 519         LIST_HEAD(list);
 520
 521         rtnl_lock();
 522         for_each_netdev(net, dev)
 523                 if (dev->priv_flags & IFF_EBRIDGE)
 524                         del_br(netdev_priv(dev), &list);
 525
 526         unregister_netdevice_many(&list);
 527         rtnl_unlock();
 528
 529 }