git.oblomov.eu Git - 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  *      $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 <net/sock.h>
  24
  25 #include "br_private.h"
  26
  27 /*
  28  * Determine initial path cost based on speed.
  29  * using recommendations from 802.1d standard
  30  *
  31  * Need to simulate user ioctl because not all device's that support
  32  * ethtool, use ethtool_ops.  Also, since driver might sleep need to
  33  * not be holding any locks.
  34  */
  35 static int port_cost(struct net_device *dev)
  36 {
  37         struct ethtool_cmd ecmd = { ETHTOOL_GSET };
  38         struct ifreq ifr;
  39         mm_segment_t old_fs;
  40         int err;
  41
  42         strncpy(ifr.ifr_name, dev->name, IFNAMSIZ);
  43         ifr.ifr_data = (void __user *) &ecmd;
  44
  45         old_fs = get_fs();
  46         set_fs(KERNEL_DS);
  47         err = dev_ethtool(&ifr);
  48         set_fs(old_fs);
  49
  50         if (!err) {
  51                 switch(ecmd.speed) {
  52                 case SPEED_100:
  53                         return 19;
  54                 case SPEED_1000:
  55                         return 4;
  56                 case SPEED_10000:
  57                         return 2;
  58                 case SPEED_10:
  59                         return 100;
  60                 }
  61         }
  62
  63         /* Old silly heuristics based on name */
  64         if (!strncmp(dev->name, "lec", 3))
  65                 return 7;
  66
  67         if (!strncmp(dev->name, "plip", 4))
  68                 return 2500;
  69
  70         return 100;     /* assume old 10Mbps */
  71 }
  72
  73
  74 /*
  75  * Check for port carrier transistions.
  76  * Called from work queue to allow for calling functions that
  77  * might sleep (such as speed check), and to debounce.
  78  */
  79 static void port_carrier_check(void *arg)
  80 {
  81         struct net_bridge_port *p = arg;
  82
  83         rtnl_lock();
  84         if (netif_carrier_ok(p->dev)) {
  85                 u32 cost = port_cost(p->dev);
  86
  87                 spin_lock_bh(&p->br->lock);
  88                 if (p->state == BR_STATE_DISABLED) {
  89                         p->path_cost = cost;
  90                         br_stp_enable_port(p);
  91                 }
  92                 spin_unlock_bh(&p->br->lock);
  93         } else {
  94                 spin_lock_bh(&p->br->lock);
  95                 if (p->state != BR_STATE_DISABLED)
  96                         br_stp_disable_port(p);
  97                 spin_unlock_bh(&p->br->lock);
  98         }
  99         rtnl_unlock();
 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         br_sysfs_freeif(p);
 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 /* called with RTNL */
 121 static void del_nbp(struct net_bridge_port *p)
 122 {
 123         struct net_bridge *br = p->br;
 124         struct net_device *dev = p->dev;
 125
 126         dev->br_port = NULL;
 127         dev_set_promiscuity(dev, -1);
 128
 129         cancel_delayed_work(&p->carrier_check);
 130         flush_scheduled_work();
 131
 132         spin_lock_bh(&br->lock);
 133         br_stp_disable_port(p);
 134         spin_unlock_bh(&br->lock);
 135
 136         br_fdb_delete_by_port(br, p);
 137
 138         list_del_rcu(&p->list);
 139
 140         del_timer_sync(&p->message_age_timer);
 141         del_timer_sync(&p->forward_delay_timer);
 142         del_timer_sync(&p->hold_timer);
 143
 144         call_rcu(&p->rcu, destroy_nbp_rcu);
 145 }
 146
 147 /* called with RTNL */
 148 static void del_br(struct net_bridge *br)
 149 {
 150         struct net_bridge_port *p, *n;
 151
 152         list_for_each_entry_safe(p, n, &br->port_list, list) {
 153                 br_sysfs_removeif(p);
 154                 del_nbp(p);
 155         }
 156
 157         del_timer_sync(&br->gc_timer);
 158
 159         br_sysfs_delbr(br->dev);
 160         unregister_netdevice(br->dev);
 161 }
 162
 163 static struct net_device *new_bridge_dev(const char *name)
 164 {
 165         struct net_bridge *br;
 166         struct net_device *dev;
 167
 168         dev = alloc_netdev(sizeof(struct net_bridge), name,
 169                            br_dev_setup);
 170
 171         if (!dev)
 172                 return NULL;
 173
 174         br = netdev_priv(dev);
 175         br->dev = dev;
 176
 177         spin_lock_init(&br->lock);
 178         INIT_LIST_HEAD(&br->port_list);
 179         spin_lock_init(&br->hash_lock);
 180
 181         br->bridge_id.prio[0] = 0x80;
 182         br->bridge_id.prio[1] = 0x00;
 183         memset(br->bridge_id.addr, 0, ETH_ALEN);
 184
 185         br->stp_enabled = 0;
 186         br->designated_root = br->bridge_id;
 187         br->root_path_cost = 0;
 188         br->root_port = 0;
 189         br->bridge_max_age = br->max_age = 20 * HZ;
 190         br->bridge_hello_time = br->hello_time = 2 * HZ;
 191         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 192         br->topology_change = 0;
 193         br->topology_change_detected = 0;
 194         br->ageing_time = 300 * HZ;
 195         INIT_LIST_HEAD(&br->age_list);
 196
 197         br_stp_timer_init(br);
 198
 199         return dev;
 200 }
 201
 202 /* find an available port number */
 203 static int find_portno(struct net_bridge *br)
 204 {
 205         int index;
 206         struct net_bridge_port *p;
 207         unsigned long *inuse;
 208
 209         inuse = kmalloc(BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long),
 210                         GFP_KERNEL);
 211         if (!inuse)
 212                 return -ENOMEM;
 213
 214         memset(inuse, 0, BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long));
 215         set_bit(0, inuse);      /* zero is reserved */
 216         list_for_each_entry(p, &br->port_list, list) {
 217                 set_bit(p->port_no, inuse);
 218         }
 219         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 220         kfree(inuse);
 221
 222         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 223 }
 224
 225 /* called with RTNL but without bridge lock */
 226 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 227                                        struct net_device *dev)
 228 {
 229         int index;
 230         struct net_bridge_port *p;
 231
 232         index = find_portno(br);
 233         if (index < 0)
 234                 return ERR_PTR(index);
 235
 236         p = kmalloc(sizeof(*p), GFP_KERNEL);
 237         if (p == NULL)
 238                 return ERR_PTR(-ENOMEM);
 239
 240         memset(p, 0, sizeof(*p));
 241         p->br = br;
 242         dev_hold(dev);
 243         p->dev = dev;
 244         p->path_cost = port_cost(dev);
 245         p->priority = 0x8000 >> BR_PORT_BITS;
 246         dev->br_port = p;
 247         p->port_no = index;
 248         br_init_port(p);
 249         p->state = BR_STATE_DISABLED;
 250         INIT_WORK(&p->carrier_check, port_carrier_check, p);
 251         kobject_init(&p->kobj);
 252
 253         return p;
 254 }
 255
 256 int br_add_bridge(const char *name)
 257 {
 258         struct net_device *dev;
 259         int ret;
 260
 261         dev = new_bridge_dev(name);
 262         if (!dev)
 263                 return -ENOMEM;
 264
 265         rtnl_lock();
 266         if (strchr(dev->name, '%')) {
 267                 ret = dev_alloc_name(dev, dev->name);
 268                 if (ret < 0)
 269                         goto err1;
 270         }
 271
 272         ret = register_netdevice(dev);
 273         if (ret)
 274                 goto err2;
 275
 276         /* network device kobject is not setup until
 277          * after rtnl_unlock does it's hotplug magic.
 278          * so hold reference to avoid race.
 279          */
 280         dev_hold(dev);
 281         rtnl_unlock();
 282
 283         ret = br_sysfs_addbr(dev);
 284         dev_put(dev);
 285
 286         if (ret)
 287                 unregister_netdev(dev);
 288  out:
 289         return ret;
 290
 291  err2:
 292         free_netdev(dev);
 293  err1:
 294         rtnl_unlock();
 295         goto out;
 296 }
 297
 298 int br_del_bridge(const char *name)
 299 {
 300         struct net_device *dev;
 301         int ret = 0;
 302
 303         rtnl_lock();
 304         dev = __dev_get_by_name(name);
 305         if (dev == NULL)
 306                 ret =  -ENXIO;  /* Could not find device */
 307
 308         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 309                 /* Attempt to delete non bridge device! */
 310                 ret = -EPERM;
 311         }
 312
 313         else if (dev->flags & IFF_UP) {
 314                 /* Not shutdown yet. */
 315                 ret = -EBUSY;
 316         }
 317
 318         else
 319                 del_br(netdev_priv(dev));
 320
 321         rtnl_unlock();
 322         return ret;
 323 }
 324
 325 /* Mtu of the bridge pseudo-device 1500 or the minimum of the ports */
 326 int br_min_mtu(const struct net_bridge *br)
 327 {
 328         const struct net_bridge_port *p;
 329         int mtu = 0;
 330
 331         ASSERT_RTNL();
 332
 333         if (list_empty(&br->port_list))
 334                 mtu = 1500;
 335         else {
 336                 list_for_each_entry(p, &br->port_list, list) {
 337                         if (!mtu  || p->dev->mtu < mtu)
 338                                 mtu = p->dev->mtu;
 339                 }
 340         }
 341         return mtu;
 342 }
 343
 344 /*
 345  * Recomputes features using slave's features
 346  */
 347 void br_features_recompute(struct net_bridge *br)
 348 {
 349         struct net_bridge_port *p;
 350         unsigned long features, checksum;
 351
 352         features = NETIF_F_SG | NETIF_F_FRAGLIST
 353                 | NETIF_F_HIGHDMA | NETIF_F_TSO;
 354         checksum = NETIF_F_IP_CSUM;     /* least commmon subset */
 355
 356         list_for_each_entry(p, &br->port_list, list) {
 357                 if (!(p->dev->features
 358                       & (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM)))
 359                         checksum = 0;
 360                 features &= p->dev->features;
 361         }
 362
 363         br->dev->features = features | checksum | NETIF_F_LLTX;
 364 }
 365
 366 /* called with RTNL */
 367 int br_add_if(struct net_bridge *br, struct net_device *dev)
 368 {
 369         struct net_bridge_port *p;
 370         int err = 0;
 371
 372         if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
 373                 return -EINVAL;
 374
 375         if (dev->hard_start_xmit == br_dev_xmit)
 376                 return -ELOOP;
 377
 378         if (dev->br_port != NULL)
 379                 return -EBUSY;
 380
 381         if (IS_ERR(p = new_nbp(br, dev)))
 382                 return PTR_ERR(p);
 383
 384         if ((err = br_fdb_insert(br, p, dev->dev_addr)))
 385                 destroy_nbp(p);
 386
 387         else if ((err = br_sysfs_addif(p)))
 388                 del_nbp(p);
 389         else {
 390                 dev_set_promiscuity(dev, 1);
 391
 392                 list_add_rcu(&p->list, &br->port_list);
 393
 394                 spin_lock_bh(&br->lock);
 395                 br_stp_recalculate_bridge_id(br);
 396                 br_features_recompute(br);
 397                 if ((br->dev->flags & IFF_UP)
 398                     && (dev->flags & IFF_UP) && netif_carrier_ok(dev))
 399                         br_stp_enable_port(p);
 400                 spin_unlock_bh(&br->lock);
 401
 402                 dev_set_mtu(br->dev, br_min_mtu(br));
 403         }
 404
 405         return err;
 406 }
 407
 408 /* called with RTNL */
 409 int br_del_if(struct net_bridge *br, struct net_device *dev)
 410 {
 411         struct net_bridge_port *p = dev->br_port;
 412
 413         if (!p || p->br != br)
 414                 return -EINVAL;
 415
 416         br_sysfs_removeif(p);
 417         del_nbp(p);
 418
 419         spin_lock_bh(&br->lock);
 420         br_stp_recalculate_bridge_id(br);
 421         br_features_recompute(br);
 422         spin_unlock_bh(&br->lock);
 423
 424         return 0;
 425 }
 426
 427 void __exit br_cleanup_bridges(void)
 428 {
 429         struct net_device *dev, *nxt;
 430
 431         rtnl_lock();
 432         for (dev = dev_base; dev; dev = nxt) {
 433                 nxt = dev->next;
 434                 if (dev->priv_flags & IFF_EBRIDGE)
 435                         del_br(dev->priv);
 436         }
 437         rtnl_unlock();
 438
 439 }