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 br_initial_port_cost(struct net_device *dev)
  36 {
  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                 default:
  62                         pr_info("bridge: can't decode speed from %s: %d\n",
  63                                 dev->name, ecmd.speed);
  64                         return 100;
  65                 }
  66         }
  67
  68         /* Old silly heuristics based on name */
  69         if (!strncmp(dev->name, "lec", 3))
  70                 return 7;
  71
  72         if (!strncmp(dev->name, "plip", 4))
  73                 return 2500;
  74
  75         return 100;     /* assume old 10Mbps */
  76 }
  77
  78 static void destroy_nbp(struct net_bridge_port *p)
  79 {
  80         struct net_device *dev = p->dev;
  81
  82         p->br = NULL;
  83         p->dev = NULL;
  84         dev_put(dev);
  85
  86         br_sysfs_freeif(p);
  87 }
  88
  89 static void destroy_nbp_rcu(struct rcu_head *head)
  90 {
  91         struct net_bridge_port *p =
  92                         container_of(head, struct net_bridge_port, rcu);
  93         destroy_nbp(p);
  94 }
  95
  96 /* called with RTNL */
  97 static void del_nbp(struct net_bridge_port *p)
  98 {
  99         struct net_bridge *br = p->br;
 100         struct net_device *dev = p->dev;
 101
 102         dev->br_port = NULL;
 103         dev_set_promiscuity(dev, -1);
 104
 105         spin_lock_bh(&br->lock);
 106         br_stp_disable_port(p);
 107         spin_unlock_bh(&br->lock);
 108
 109         br_fdb_delete_by_port(br, p);
 110
 111         list_del_rcu(&p->list);
 112
 113         del_timer_sync(&p->message_age_timer);
 114         del_timer_sync(&p->forward_delay_timer);
 115         del_timer_sync(&p->hold_timer);
 116
 117         call_rcu(&p->rcu, destroy_nbp_rcu);
 118 }
 119
 120 /* called with RTNL */
 121 static void del_br(struct net_bridge *br)
 122 {
 123         struct net_bridge_port *p, *n;
 124
 125         list_for_each_entry_safe(p, n, &br->port_list, list) {
 126                 br_sysfs_removeif(p);
 127                 del_nbp(p);
 128         }
 129
 130         del_timer_sync(&br->gc_timer);
 131
 132         br_sysfs_delbr(br->dev);
 133         unregister_netdevice(br->dev);
 134 }
 135
 136 static struct net_device *new_bridge_dev(const char *name)
 137 {
 138         struct net_bridge *br;
 139         struct net_device *dev;
 140
 141         dev = alloc_netdev(sizeof(struct net_bridge), name,
 142                            br_dev_setup);
 143
 144         if (!dev)
 145                 return NULL;
 146
 147         br = netdev_priv(dev);
 148         br->dev = dev;
 149
 150         spin_lock_init(&br->lock);
 151         INIT_LIST_HEAD(&br->port_list);
 152         spin_lock_init(&br->hash_lock);
 153
 154         br->bridge_id.prio[0] = 0x80;
 155         br->bridge_id.prio[1] = 0x00;
 156         memset(br->bridge_id.addr, 0, ETH_ALEN);
 157
 158         br->stp_enabled = 0;
 159         br->designated_root = br->bridge_id;
 160         br->root_path_cost = 0;
 161         br->root_port = 0;
 162         br->bridge_max_age = br->max_age = 20 * HZ;
 163         br->bridge_hello_time = br->hello_time = 2 * HZ;
 164         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 165         br->topology_change = 0;
 166         br->topology_change_detected = 0;
 167         br->ageing_time = 300 * HZ;
 168         INIT_LIST_HEAD(&br->age_list);
 169
 170         br_stp_timer_init(br);
 171
 172         return dev;
 173 }
 174
 175 /* find an available port number */
 176 static int find_portno(struct net_bridge *br)
 177 {
 178         int index;
 179         struct net_bridge_port *p;
 180         unsigned long *inuse;
 181
 182         inuse = kmalloc(BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long),
 183                         GFP_KERNEL);
 184         if (!inuse)
 185                 return -ENOMEM;
 186
 187         memset(inuse, 0, BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long));
 188         set_bit(0, inuse);      /* zero is reserved */
 189         list_for_each_entry(p, &br->port_list, list) {
 190                 set_bit(p->port_no, inuse);
 191         }
 192         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 193         kfree(inuse);
 194
 195         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 196 }
 197
 198 /* called with RTNL */
 199 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 200                                        struct net_device *dev,
 201                                        unsigned long cost)
 202 {
 203         int index;
 204         struct net_bridge_port *p;
 205
 206         index = find_portno(br);
 207         if (index < 0)
 208                 return ERR_PTR(index);
 209
 210         p = kmalloc(sizeof(*p), GFP_KERNEL);
 211         if (p == NULL)
 212                 return ERR_PTR(-ENOMEM);
 213
 214         memset(p, 0, sizeof(*p));
 215         p->br = br;
 216         dev_hold(dev);
 217         p->dev = dev;
 218         p->path_cost = cost;
 219         p->priority = 0x8000 >> BR_PORT_BITS;
 220         dev->br_port = p;
 221         p->port_no = index;
 222         br_init_port(p);
 223         p->state = BR_STATE_DISABLED;
 224         kobject_init(&p->kobj);
 225
 226         return p;
 227 }
 228
 229 int br_add_bridge(const char *name)
 230 {
 231         struct net_device *dev;
 232         int ret;
 233
 234         dev = new_bridge_dev(name);
 235         if (!dev)
 236                 return -ENOMEM;
 237
 238         rtnl_lock();
 239         if (strchr(dev->name, '%')) {
 240                 ret = dev_alloc_name(dev, dev->name);
 241                 if (ret < 0)
 242                         goto err1;
 243         }
 244
 245         ret = register_netdevice(dev);
 246         if (ret)
 247                 goto err2;
 248
 249         /* network device kobject is not setup until
 250          * after rtnl_unlock does it's hotplug magic.
 251          * so hold reference to avoid race.
 252          */
 253         dev_hold(dev);
 254         rtnl_unlock();
 255
 256         ret = br_sysfs_addbr(dev);
 257         dev_put(dev);
 258
 259         if (ret)
 260                 unregister_netdev(dev);
 261  out:
 262         return ret;
 263
 264  err2:
 265         free_netdev(dev);
 266  err1:
 267         rtnl_unlock();
 268         goto out;
 269 }
 270
 271 int br_del_bridge(const char *name)
 272 {
 273         struct net_device *dev;
 274         int ret = 0;
 275
 276         rtnl_lock();
 277         dev = __dev_get_by_name(name);
 278         if (dev == NULL)
 279                 ret =  -ENXIO;  /* Could not find device */
 280
 281         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 282                 /* Attempt to delete non bridge device! */
 283                 ret = -EPERM;
 284         }
 285
 286         else if (dev->flags & IFF_UP) {
 287                 /* Not shutdown yet. */
 288                 ret = -EBUSY;
 289         }
 290
 291         else
 292                 del_br(netdev_priv(dev));
 293
 294         rtnl_unlock();
 295         return ret;
 296 }
 297
 298 /* Mtu of the bridge pseudo-device 1500 or the minimum of the ports */
 299 int br_min_mtu(const struct net_bridge *br)
 300 {
 301         const struct net_bridge_port *p;
 302         int mtu = 0;
 303
 304         ASSERT_RTNL();
 305
 306         if (list_empty(&br->port_list))
 307                 mtu = 1500;
 308         else {
 309                 list_for_each_entry(p, &br->port_list, list) {
 310                         if (!mtu  || p->dev->mtu < mtu)
 311                                 mtu = p->dev->mtu;
 312                 }
 313         }
 314         return mtu;
 315 }
 316
 317 /*
 318  * Recomputes features using slave's features
 319  */
 320 void br_features_recompute(struct net_bridge *br)
 321 {
 322         struct net_bridge_port *p;
 323         unsigned long features, checksum;
 324
 325         features = NETIF_F_SG | NETIF_F_FRAGLIST
 326                 | NETIF_F_HIGHDMA | NETIF_F_TSO;
 327         checksum = NETIF_F_IP_CSUM;     /* least commmon subset */
 328
 329         list_for_each_entry(p, &br->port_list, list) {
 330                 if (!(p->dev->features
 331                       & (NETIF_F_IP_CSUM|NETIF_F_NO_CSUM|NETIF_F_HW_CSUM)))
 332                         checksum = 0;
 333                 features &= p->dev->features;
 334         }
 335
 336         br->dev->features = features | checksum | NETIF_F_LLTX;
 337 }
 338
 339 /* called with RTNL */
 340 int br_add_if(struct net_bridge *br, struct net_device *dev)
 341 {
 342         struct net_bridge_port *p;
 343         int err = 0;
 344
 345         if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
 346                 return -EINVAL;
 347
 348         if (dev->hard_start_xmit == br_dev_xmit)
 349                 return -ELOOP;
 350
 351         if (dev->br_port != NULL)
 352                 return -EBUSY;
 353
 354         if (IS_ERR(p = new_nbp(br, dev, br_initial_port_cost(dev))))
 355                 return PTR_ERR(p);
 356
 357         if ((err = br_fdb_insert(br, p, dev->dev_addr)))
 358                 destroy_nbp(p);
 359
 360         else if ((err = br_sysfs_addif(p)))
 361                 del_nbp(p);
 362         else {
 363                 dev_set_promiscuity(dev, 1);
 364
 365                 list_add_rcu(&p->list, &br->port_list);
 366
 367                 spin_lock_bh(&br->lock);
 368                 br_stp_recalculate_bridge_id(br);
 369                 if ((br->dev->flags & IFF_UP)
 370                     && (dev->flags & IFF_UP) && netif_carrier_ok(dev))
 371                         br_stp_enable_port(p);
 372                 spin_unlock_bh(&br->lock);
 373
 374                 dev_set_mtu(br->dev, br_min_mtu(br));
 375         }
 376
 377         return err;
 378 }
 379
 380 /* called with RTNL */
 381 int br_del_if(struct net_bridge *br, struct net_device *dev)
 382 {
 383         struct net_bridge_port *p = dev->br_port;
 384
 385         if (!p || p->br != br)
 386                 return -EINVAL;
 387
 388         br_sysfs_removeif(p);
 389         del_nbp(p);
 390
 391         spin_lock_bh(&br->lock);
 392         br_stp_recalculate_bridge_id(br);
 393         br_features_recompute(br);
 394         spin_unlock_bh(&br->lock);
 395
 396         return 0;
 397 }
 398
 399 void __exit br_cleanup_bridges(void)
 400 {
 401         struct net_device *dev, *nxt;
 402
 403         rtnl_lock();
 404         for (dev = dev_base; dev; dev = nxt) {
 405                 nxt = dev->next;
 406                 if (dev->priv_flags & IFF_EBRIDGE)
 407                         del_br(dev->priv);
 408         }
 409         rtnl_unlock();
 410
 411 }