SAFE public projects git trees. - safe/jmp/linux-2.6/blob - 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/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         br_multicast_del_port(p);
 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, struct list_head *head)
 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_queue(br->dev, head);
 171 }
 172
 173 static struct net_device *new_bridge_dev(struct net *net, 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         dev_net_set(dev, net);
 184
 185         br = netdev_priv(dev);
 186         br->dev = dev;
 187
 188         br->stats = alloc_percpu(struct br_cpu_netstats);
 189         if (!br->stats) {
 190                 free_netdev(dev);
 191                 return NULL;
 192         }
 193
 194         spin_lock_init(&br->lock);
 195         INIT_LIST_HEAD(&br->port_list);
 196         spin_lock_init(&br->hash_lock);
 197
 198         br->bridge_id.prio[0] = 0x80;
 199         br->bridge_id.prio[1] = 0x00;
 200
 201         memcpy(br->group_addr, br_group_address, ETH_ALEN);
 202
 203         br->feature_mask = dev->features;
 204         br->stp_enabled = BR_NO_STP;
 205         br->designated_root = br->bridge_id;
 206         br->root_path_cost = 0;
 207         br->root_port = 0;
 208         br->bridge_max_age = br->max_age = 20 * HZ;
 209         br->bridge_hello_time = br->hello_time = 2 * HZ;
 210         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 211         br->topology_change = 0;
 212         br->topology_change_detected = 0;
 213         br->ageing_time = 300 * HZ;
 214
 215         br_netfilter_rtable_init(br);
 216
 217         br_stp_timer_init(br);
 218         br_multicast_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         p->flags = 0;
 267         br_init_port(p);
 268         p->state = BR_STATE_DISABLED;
 269         br_stp_port_timer_init(p);
 270         br_multicast_add_port(p);
 271
 272         return p;
 273 }
 274
 275 static struct device_type br_type = {
 276         .name   = "bridge",
 277 };
 278
 279 int br_add_bridge(struct net *net, const char *name)
 280 {
 281         struct net_device *dev;
 282         int ret;
 283
 284         dev = new_bridge_dev(net, 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                         goto out_free;
 293         }
 294
 295         SET_NETDEV_DEVTYPE(dev, &br_type);
 296
 297         ret = register_netdevice(dev);
 298         if (ret)
 299                 goto out_free;
 300
 301         ret = br_sysfs_addbr(dev);
 302         if (ret)
 303                 unregister_netdevice(dev);
 304  out:
 305         rtnl_unlock();
 306         return ret;
 307
 308 out_free:
 309         free_netdev(dev);
 310         goto out;
 311 }
 312
 313 int br_del_bridge(struct net *net, const char *name)
 314 {
 315         struct net_device *dev;
 316         int ret = 0;
 317
 318         rtnl_lock();
 319         dev = __dev_get_by_name(net, name);
 320         if (dev == NULL)
 321                 ret =  -ENXIO;  /* Could not find device */
 322
 323         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 324                 /* Attempt to delete non bridge device! */
 325                 ret = -EPERM;
 326         }
 327
 328         else if (dev->flags & IFF_UP) {
 329                 /* Not shutdown yet. */
 330                 ret = -EBUSY;
 331         }
 332
 333         else
 334                 del_br(netdev_priv(dev), NULL);
 335
 336         rtnl_unlock();
 337         return ret;
 338 }
 339
 340 /* MTU of the bridge pseudo-device: ETH_DATA_LEN or the minimum of the ports */
 341 int br_min_mtu(const struct net_bridge *br)
 342 {
 343         const struct net_bridge_port *p;
 344         int mtu = 0;
 345
 346         ASSERT_RTNL();
 347
 348         if (list_empty(&br->port_list))
 349                 mtu = ETH_DATA_LEN;
 350         else {
 351                 list_for_each_entry(p, &br->port_list, list) {
 352                         if (!mtu  || p->dev->mtu < mtu)
 353                                 mtu = p->dev->mtu;
 354                 }
 355         }
 356         return mtu;
 357 }
 358
 359 /*
 360  * Recomputes features using slave's features
 361  */
 362 void br_features_recompute(struct net_bridge *br)
 363 {
 364         struct net_bridge_port *p;
 365         unsigned long features, mask;
 366
 367         features = mask = br->feature_mask;
 368         if (list_empty(&br->port_list))
 369                 goto done;
 370
 371         features &= ~NETIF_F_ONE_FOR_ALL;
 372
 373         list_for_each_entry(p, &br->port_list, list) {
 374                 features = netdev_increment_features(features,
 375                                                      p->dev->features, mask);
 376         }
 377
 378 done:
 379         br->dev->features = netdev_fix_features(features, NULL);
 380 }
 381
 382 /* called with RTNL */
 383 int br_add_if(struct net_bridge *br, struct net_device *dev)
 384 {
 385         struct net_bridge_port *p;
 386         int err = 0;
 387
 388         /* Don't allow bridging non-ethernet like devices */
 389         if ((dev->flags & IFF_LOOPBACK) ||
 390             dev->type != ARPHRD_ETHER || dev->addr_len != ETH_ALEN)
 391                 return -EINVAL;
 392
 393         /* No bridging of bridges */
 394         if (dev->netdev_ops->ndo_start_xmit == br_dev_xmit)
 395                 return -ELOOP;
 396
 397         /* Device is already being bridged */
 398         if (dev->br_port != NULL)
 399                 return -EBUSY;
 400
 401         /* No bridging devices that dislike that (e.g. wireless) */
 402         if (dev->priv_flags & IFF_DONT_BRIDGE)
 403                 return -EOPNOTSUPP;
 404
 405         p = new_nbp(br, dev);
 406         if (IS_ERR(p))
 407                 return PTR_ERR(p);
 408
 409         err = dev_set_promiscuity(dev, 1);
 410         if (err)
 411                 goto put_back;
 412
 413         err = kobject_init_and_add(&p->kobj, &brport_ktype, &(dev->dev.kobj),
 414                                    SYSFS_BRIDGE_PORT_ATTR);
 415         if (err)
 416                 goto err0;
 417
 418         err = br_fdb_insert(br, p, dev->dev_addr);
 419         if (err)
 420                 goto err1;
 421
 422         err = br_sysfs_addif(p);
 423         if (err)
 424                 goto err2;
 425
 426         rcu_assign_pointer(dev->br_port, p);
 427         dev_disable_lro(dev);
 428
 429         list_add_rcu(&p->list, &br->port_list);
 430
 431         spin_lock_bh(&br->lock);
 432         br_stp_recalculate_bridge_id(br);
 433         br_features_recompute(br);
 434
 435         if ((dev->flags & IFF_UP) && netif_carrier_ok(dev) &&
 436             (br->dev->flags & IFF_UP))
 437                 br_stp_enable_port(p);
 438         spin_unlock_bh(&br->lock);
 439
 440         br_ifinfo_notify(RTM_NEWLINK, p);
 441
 442         dev_set_mtu(br->dev, br_min_mtu(br));
 443
 444         kobject_uevent(&p->kobj, KOBJ_ADD);
 445
 446         return 0;
 447 err2:
 448         br_fdb_delete_by_port(br, p, 1);
 449 err1:
 450         kobject_put(&p->kobj);
 451         p = NULL; /* kobject_put frees */
 452 err0:
 453         dev_set_promiscuity(dev, -1);
 454 put_back:
 455         dev_put(dev);
 456         kfree(p);
 457         return err;
 458 }
 459
 460 /* called with RTNL */
 461 int br_del_if(struct net_bridge *br, struct net_device *dev)
 462 {
 463         struct net_bridge_port *p = dev->br_port;
 464
 465         if (!p || p->br != br)
 466                 return -EINVAL;
 467
 468         del_nbp(p);
 469
 470         spin_lock_bh(&br->lock);
 471         br_stp_recalculate_bridge_id(br);
 472         br_features_recompute(br);
 473         spin_unlock_bh(&br->lock);
 474
 475         return 0;
 476 }
 477
 478 void __net_exit br_net_exit(struct net *net)
 479 {
 480         struct net_device *dev;
 481         LIST_HEAD(list);
 482
 483         rtnl_lock();
 484         for_each_netdev(net, dev)
 485                 if (dev->priv_flags & IFF_EBRIDGE)
 486                         del_br(netdev_priv(dev), &list);
 487
 488         unregister_netdevice_many(&list);
 489         rtnl_unlock();
 490
 491 }