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 *) &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(void *arg)
  79 {
  80         struct net_bridge_port *p = arg;
  81         struct net_device *dev = p->dev;
  82
  83         dev->br_port = NULL;
  84         p->br = NULL;
  85         p->dev = NULL;
  86         dev_put(dev);
  87
  88         br_sysfs_freeif(p);
  89 }
  90
  91 /* called with RTNL */
  92 static void del_nbp(struct net_bridge_port *p)
  93 {
  94         struct net_bridge *br = p->br;
  95         struct net_device *dev = p->dev;
  96
  97         dev_set_promiscuity(dev, -1);
  98
  99         spin_lock_bh(&br->lock);
 100         br_stp_disable_port(p);
 101         spin_unlock_bh(&br->lock);
 102
 103         br_fdb_delete_by_port(br, p);
 104
 105         list_del_rcu(&p->list);
 106
 107         del_timer_sync(&p->message_age_timer);
 108         del_timer_sync(&p->forward_delay_timer);
 109         del_timer_sync(&p->hold_timer);
 110
 111         call_rcu(&p->rcu, destroy_nbp, p);
 112 }
 113
 114 /* called with RTNL */
 115 static void del_br(struct net_bridge *br)
 116 {
 117         struct net_bridge_port *p, *n;
 118
 119         list_for_each_entry_safe(p, n, &br->port_list, list) {
 120                 br_sysfs_removeif(p);
 121                 del_nbp(p);
 122         }
 123
 124         del_timer_sync(&br->gc_timer);
 125
 126         br_sysfs_delbr(br->dev);
 127         unregister_netdevice(br->dev);
 128 }
 129
 130 static struct net_device *new_bridge_dev(const char *name)
 131 {
 132         struct net_bridge *br;
 133         struct net_device *dev;
 134
 135         dev = alloc_netdev(sizeof(struct net_bridge), name,
 136                            br_dev_setup);
 137
 138         if (!dev)
 139                 return NULL;
 140
 141         br = netdev_priv(dev);
 142         br->dev = dev;
 143
 144         br->lock = SPIN_LOCK_UNLOCKED;
 145         INIT_LIST_HEAD(&br->port_list);
 146         br->hash_lock = RW_LOCK_UNLOCKED;
 147
 148         br->bridge_id.prio[0] = 0x80;
 149         br->bridge_id.prio[1] = 0x00;
 150         memset(br->bridge_id.addr, 0, ETH_ALEN);
 151
 152         br->stp_enabled = 0;
 153         br->designated_root = br->bridge_id;
 154         br->root_path_cost = 0;
 155         br->root_port = 0;
 156         br->bridge_max_age = br->max_age = 20 * HZ;
 157         br->bridge_hello_time = br->hello_time = 2 * HZ;
 158         br->bridge_forward_delay = br->forward_delay = 15 * HZ;
 159         br->topology_change = 0;
 160         br->topology_change_detected = 0;
 161         br->ageing_time = 300 * HZ;
 162         INIT_LIST_HEAD(&br->age_list);
 163
 164         br_stp_timer_init(br);
 165
 166         return dev;
 167 }
 168
 169 /* find an available port number */
 170 static int find_portno(struct net_bridge *br)
 171 {
 172         int index;
 173         struct net_bridge_port *p;
 174         unsigned long *inuse;
 175
 176         inuse = kmalloc(BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long),
 177                         GFP_KERNEL);
 178         if (!inuse)
 179                 return -ENOMEM;
 180
 181         memset(inuse, 0, BITS_TO_LONGS(BR_MAX_PORTS)*sizeof(unsigned long));
 182         set_bit(0, inuse);      /* zero is reserved */
 183         list_for_each_entry(p, &br->port_list, list) {
 184                 set_bit(p->port_no, inuse);
 185         }
 186         index = find_first_zero_bit(inuse, BR_MAX_PORTS);
 187         kfree(inuse);
 188
 189         return (index >= BR_MAX_PORTS) ? -EXFULL : index;
 190 }
 191
 192 /* called with RTNL */
 193 static struct net_bridge_port *new_nbp(struct net_bridge *br,
 194                                        struct net_device *dev,
 195                                        unsigned long cost)
 196 {
 197         int index;
 198         struct net_bridge_port *p;
 199
 200         index = find_portno(br);
 201         if (index < 0)
 202                 return ERR_PTR(index);
 203
 204         p = kmalloc(sizeof(*p), GFP_KERNEL);
 205         if (p == NULL)
 206                 return ERR_PTR(-ENOMEM);
 207
 208         memset(p, 0, sizeof(*p));
 209         p->br = br;
 210         dev_hold(dev);
 211         p->dev = dev;
 212         p->path_cost = cost;
 213         p->priority = 0x8000 >> BR_PORT_BITS;
 214         dev->br_port = p;
 215         p->port_no = index;
 216         br_init_port(p);
 217         p->state = BR_STATE_DISABLED;
 218         kobject_init(&p->kobj);
 219
 220         return p;
 221 }
 222
 223 int br_add_bridge(const char *name)
 224 {
 225         struct net_device *dev;
 226         int ret;
 227
 228         dev = new_bridge_dev(name);
 229         if (!dev)
 230                 return -ENOMEM;
 231
 232         rtnl_lock();
 233         if (strchr(dev->name, '%')) {
 234                 ret = dev_alloc_name(dev, dev->name);
 235                 if (ret < 0)
 236                         goto err1;
 237         }
 238
 239         ret = register_netdevice(dev);
 240         if (ret)
 241                 goto err2;
 242
 243         /* network device kobject is not setup until
 244          * after rtnl_unlock does it's hotplug magic.
 245          * so hold reference to avoid race.
 246          */
 247         dev_hold(dev);
 248         rtnl_unlock();
 249
 250         ret = br_sysfs_addbr(dev);
 251         dev_put(dev);
 252
 253         if (ret)
 254                 unregister_netdev(dev);
 255  out:
 256         return ret;
 257
 258  err2:
 259         free_netdev(dev);
 260  err1:
 261         rtnl_unlock();
 262         goto out;
 263 }
 264
 265 int br_del_bridge(const char *name)
 266 {
 267         struct net_device *dev;
 268         int ret = 0;
 269
 270         rtnl_lock();
 271         dev = __dev_get_by_name(name);
 272         if (dev == NULL)
 273                 ret =  -ENXIO;  /* Could not find device */
 274
 275         else if (!(dev->priv_flags & IFF_EBRIDGE)) {
 276                 /* Attempt to delete non bridge device! */
 277                 ret = -EPERM;
 278         }
 279
 280         else if (dev->flags & IFF_UP) {
 281                 /* Not shutdown yet. */
 282                 ret = -EBUSY;
 283         }
 284
 285         else
 286                 del_br(netdev_priv(dev));
 287
 288         rtnl_unlock();
 289         return ret;
 290 }
 291
 292 /* called with RTNL */
 293 int br_add_if(struct net_bridge *br, struct net_device *dev)
 294 {
 295         struct net_bridge_port *p;
 296         int err = 0;
 297
 298         if (dev->flags & IFF_LOOPBACK || dev->type != ARPHRD_ETHER)
 299                 return -EINVAL;
 300
 301         if (dev->hard_start_xmit == br_dev_xmit)
 302                 return -ELOOP;
 303
 304         if (dev->br_port != NULL)
 305                 return -EBUSY;
 306
 307         if (IS_ERR(p = new_nbp(br, dev, br_initial_port_cost(dev))))
 308                 return PTR_ERR(p);
 309
 310         if ((err = br_fdb_insert(br, p, dev->dev_addr, 1)))
 311                 destroy_nbp(p);
 312
 313         else if ((err = br_sysfs_addif(p)))
 314                 del_nbp(p);
 315         else {
 316                 dev_set_promiscuity(dev, 1);
 317
 318                 list_add_rcu(&p->list, &br->port_list);
 319
 320                 spin_lock_bh(&br->lock);
 321                 br_stp_recalculate_bridge_id(br);
 322                 if ((br->dev->flags & IFF_UP) && (dev->flags & IFF_UP))
 323                         br_stp_enable_port(p);
 324                 spin_unlock_bh(&br->lock);
 325         }
 326
 327         return err;
 328 }
 329
 330 /* called with RTNL */
 331 int br_del_if(struct net_bridge *br, struct net_device *dev)
 332 {
 333         struct net_bridge_port *p = dev->br_port;
 334
 335         if (!p || p->br != br)
 336                 return -EINVAL;
 337
 338         br_sysfs_removeif(p);
 339         del_nbp(p);
 340
 341         spin_lock_bh(&br->lock);
 342         br_stp_recalculate_bridge_id(br);
 343         spin_unlock_bh(&br->lock);
 344
 345         return 0;
 346 }
 347
 348 void __exit br_cleanup_bridges(void)
 349 {
 350         struct net_device *dev, *nxt;
 351
 352         rtnl_lock();
 353         for (dev = dev_base; dev; dev = nxt) {
 354                 nxt = dev->next;
 355                 if (dev->priv_flags & IFF_EBRIDGE)
 356                         del_br(dev->priv);
 357         }
 358         rtnl_unlock();
 359
 360 }