drivers/net/eql.c

   1 /*
   2  * Equalizer Load-balancer for serial network interfaces.
   3  *
   4  * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
   5  * NCM: Network and Communications Management, Inc.
   6  *
   7  * (c) Copyright 2002 David S. Miller (davem@redhat.com)
   8  *
   9  *      This software may be used and distributed according to the terms
  10  *      of the GNU General Public License, incorporated herein by reference.
  11  *
  12  * The author may be reached as simon@ncm.com, or C/O
  13  *    NCM
  14  *    Attn: Simon Janes
  15  *    6803 Whittier Ave
  16  *    McLean VA 22101
  17  *    Phone: 1-703-847-0040 ext 103
  18  */
  19
  20 /*
  21  * Sources:
  22  *   skeleton.c by Donald Becker.
  23  * Inspirations:
  24  *   The Harried and Overworked Alan Cox
  25  * Conspiracies:
  26  *   The Alan Cox and Mike McLagan plot to get someone else to do the code,
  27  *   which turned out to be me.
  28  */
  29
  30 /*
  31  * $Log: eql.c,v $
  32  * Revision 1.2  1996/04/11 17:51:52  guru
  33  * Added one-line eql_remove_slave patch.
  34  *
  35  * Revision 1.1  1996/04/11 17:44:17  guru
  36  * Initial revision
  37  *
  38  * Revision 3.13  1996/01/21  15:17:18  alan
  39  * tx_queue_len changes.
  40  * reformatted.
  41  *
  42  * Revision 3.12  1995/03/22  21:07:51  anarchy
  43  * Added capable() checks on configuration.
  44  * Moved header file.
  45  *
  46  * Revision 3.11  1995/01/19  23:14:31  guru
  47  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
  48  *                      (priority_Bps) + bytes_queued * 8;
  49  *
  50  * Revision 3.10  1995/01/19  23:07:53  guru
  51  * back to
  52  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
  53  *                      (priority_Bps) + bytes_queued;
  54  *
  55  * Revision 3.9  1995/01/19  22:38:20  guru
  56  *                    slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
  57  *                      (priority_Bps) + bytes_queued * 4;
  58  *
  59  * Revision 3.8  1995/01/19  22:30:55  guru
  60  *       slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
  61  *                      (priority_Bps) + bytes_queued * 2;
  62  *
  63  * Revision 3.7  1995/01/19  21:52:35  guru
  64  * printk's trimmed out.
  65  *
  66  * Revision 3.6  1995/01/19  21:49:56  guru
  67  * This is working pretty well. I gained 1 K/s in speed.. now it's just
  68  * robustness and printk's to be diked out.
  69  *
  70  * Revision 3.5  1995/01/18  22:29:59  guru
  71  * still crashes the kernel when the lock_wait thing is woken up.
  72  *
  73  * Revision 3.4  1995/01/18  21:59:47  guru
  74  * Broken set-bit locking snapshot
  75  *
  76  * Revision 3.3  1995/01/17  22:09:18  guru
  77  * infinite sleep in a lock somewhere..
  78  *
  79  * Revision 3.2  1995/01/15  16:46:06  guru
  80  * Log trimmed of non-pertinent 1.x branch messages
  81  *
  82  * Revision 3.1  1995/01/15  14:41:45  guru
  83  * New Scheduler and timer stuff...
  84  *
  85  * Revision 1.15  1995/01/15  14:29:02  guru
  86  * Will make 1.14 (now 1.15) the 3.0 branch, and the 1.12 the 2.0 branch, the one
  87  * with the dumber scheduler
  88  *
  89  * Revision 1.14  1995/01/15  02:37:08  guru
  90  * shock.. the kept-new-versions could have zonked working
  91  * stuff.. shudder
  92  *
  93  * Revision 1.13  1995/01/15  02:36:31  guru
  94  * big changes
  95  *
  96  *      scheduler was torn out and replaced with something smarter
  97  *
  98  *      global names not prefixed with eql_ were renamed to protect
  99  *      against namespace collisions
 100  *
 101  *      a few more abstract interfaces were added to facilitate any
 102  *      potential change of datastructure.  the driver is still using
 103  *      a linked list of slaves.  going to a heap would be a bit of
 104  *      an overkill.
 105  *
 106  *      this compiles fine with no warnings.
 107  *
 108  *      the locking mechanism and timer stuff must be written however,
 109  *      this version will not work otherwise
 110  *
 111  * Sorry, I had to rewrite most of this for 2.5.x -DaveM
 112  */
 113
 114 #include <linux/capability.h>
 115 #include <linux/module.h>
 116 #include <linux/kernel.h>
 117 #include <linux/init.h>
 118 #include <linux/slab.h>
 119 #include <linux/timer.h>
 120 #include <linux/netdevice.h>
 121 #include <net/net_namespace.h>
 122
 123 #include <linux/if.h>
 124 #include <linux/if_arp.h>
 125 #include <linux/if_eql.h>
 126
 127 #include <asm/uaccess.h>
 128
 129 static int eql_open(struct net_device *dev);
 130 static int eql_close(struct net_device *dev);
 131 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
 132 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
 133
 134 #define eql_is_slave(dev)       ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
 135 #define eql_is_master(dev)      ((dev->flags & IFF_MASTER) == IFF_MASTER)
 136
 137 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
 138
 139 static void eql_timer(unsigned long param)
 140 {
 141         equalizer_t *eql = (equalizer_t *) param;
 142         struct list_head *this, *tmp, *head;
 143
 144         spin_lock_bh(&eql->queue.lock);
 145         head = &eql->queue.all_slaves;
 146         list_for_each_safe(this, tmp, head) {
 147                 slave_t *slave = list_entry(this, slave_t, list);
 148
 149                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
 150                         slave->bytes_queued -= slave->priority_Bps;
 151                         if (slave->bytes_queued < 0)
 152                                 slave->bytes_queued = 0;
 153                 } else {
 154                         eql_kill_one_slave(&eql->queue, slave);
 155                 }
 156
 157         }
 158         spin_unlock_bh(&eql->queue.lock);
 159
 160         eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
 161         add_timer(&eql->timer);
 162 }
 163
 164 static const char version[] __initconst =
 165         "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
 166
 167 static const struct net_device_ops eql_netdev_ops = {
 168         .ndo_open       = eql_open,
 169         .ndo_stop       = eql_close,
 170         .ndo_do_ioctl   = eql_ioctl,
 171         .ndo_start_xmit = eql_slave_xmit,
 172 };
 173
 174 static void __init eql_setup(struct net_device *dev)
 175 {
 176         equalizer_t *eql = netdev_priv(dev);
 177
 178         init_timer(&eql->timer);
 179         eql->timer.data         = (unsigned long) eql;
 180         eql->timer.expires      = jiffies + EQL_DEFAULT_RESCHED_IVAL;
 181         eql->timer.function     = eql_timer;
 182
 183         spin_lock_init(&eql->queue.lock);
 184         INIT_LIST_HEAD(&eql->queue.all_slaves);
 185         eql->queue.master_dev   = dev;
 186
 187         dev->netdev_ops         = &eql_netdev_ops;
 188
 189         /*
 190          *      Now we undo some of the things that eth_setup does
 191          *      that we don't like
 192          */
 193
 194         dev->mtu                = EQL_DEFAULT_MTU;      /* set to 576 in if_eql.h */
 195         dev->flags              = IFF_MASTER;
 196
 197         dev->type               = ARPHRD_SLIP;
 198         dev->tx_queue_len       = 5;            /* Hands them off fast */
 199         dev->priv_flags        &= ~IFF_XMIT_DST_RELEASE;
 200 }
 201
 202 static int eql_open(struct net_device *dev)
 203 {
 204         equalizer_t *eql = netdev_priv(dev);
 205
 206         /* XXX We should force this off automatically for the user. */
 207         printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
 208                "your slave devices.\n", dev->name);
 209
 210         BUG_ON(!list_empty(&eql->queue.all_slaves));
 211
 212         eql->min_slaves = 1;
 213         eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
 214
 215         add_timer(&eql->timer);
 216
 217         return 0;
 218 }
 219
 220 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
 221 {
 222         list_del(&slave->list);
 223         queue->num_slaves--;
 224         slave->dev->flags &= ~IFF_SLAVE;
 225         dev_put(slave->dev);
 226         kfree(slave);
 227 }
 228
 229 static void eql_kill_slave_queue(slave_queue_t *queue)
 230 {
 231         struct list_head *head, *tmp, *this;
 232
 233         spin_lock_bh(&queue->lock);
 234
 235         head = &queue->all_slaves;
 236         list_for_each_safe(this, tmp, head) {
 237                 slave_t *s = list_entry(this, slave_t, list);
 238
 239                 eql_kill_one_slave(queue, s);
 240         }
 241
 242         spin_unlock_bh(&queue->lock);
 243 }
 244
 245 static int eql_close(struct net_device *dev)
 246 {
 247         equalizer_t *eql = netdev_priv(dev);
 248
 249         /*
 250          *      The timer has to be stopped first before we start hacking away
 251          *      at the data structure it scans every so often...
 252          */
 253
 254         del_timer_sync(&eql->timer);
 255
 256         eql_kill_slave_queue(&eql->queue);
 257
 258         return 0;
 259 }
 260
 261 static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
 262 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
 263
 264 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
 265 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
 266
 267 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
 268 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
 269
 270 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 271 {
 272         if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
 273             !capable(CAP_NET_ADMIN))
 274                 return -EPERM;
 275
 276         switch (cmd) {
 277                 case EQL_ENSLAVE:
 278                         return eql_enslave(dev, ifr->ifr_data);
 279                 case EQL_EMANCIPATE:
 280                         return eql_emancipate(dev, ifr->ifr_data);
 281                 case EQL_GETSLAVECFG:
 282                         return eql_g_slave_cfg(dev, ifr->ifr_data);
 283                 case EQL_SETSLAVECFG:
 284                         return eql_s_slave_cfg(dev, ifr->ifr_data);
 285                 case EQL_GETMASTRCFG:
 286                         return eql_g_master_cfg(dev, ifr->ifr_data);
 287                 case EQL_SETMASTRCFG:
 288                         return eql_s_master_cfg(dev, ifr->ifr_data);
 289                 default:
 290                         return -EOPNOTSUPP;
 291         }
 292 }
 293
 294 /* queue->lock must be held */
 295 static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
 296 {
 297         unsigned long best_load = ~0UL;
 298         struct list_head *this, *tmp, *head;
 299         slave_t *best_slave;
 300
 301         best_slave = NULL;
 302
 303         /* Make a pass to set the best slave. */
 304         head = &queue->all_slaves;
 305         list_for_each_safe(this, tmp, head) {
 306                 slave_t *slave = list_entry(this, slave_t, list);
 307                 unsigned long slave_load, bytes_queued, priority_Bps;
 308
 309                 /* Go through the slave list once, updating best_slave
 310                  * whenever a new best_load is found.
 311                  */
 312                 bytes_queued = slave->bytes_queued;
 313                 priority_Bps = slave->priority_Bps;
 314                 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
 315                         slave_load = (~0UL - (~0UL / 2)) -
 316                                 (priority_Bps) + bytes_queued * 8;
 317
 318                         if (slave_load < best_load) {
 319                                 best_load = slave_load;
 320                                 best_slave = slave;
 321                         }
 322                 } else {
 323                         /* We found a dead slave, kill it. */
 324                         eql_kill_one_slave(queue, slave);
 325                 }
 326         }
 327         return best_slave;
 328 }
 329
 330 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
 331 {
 332         equalizer_t *eql = netdev_priv(dev);
 333         slave_t *slave;
 334
 335         spin_lock(&eql->queue.lock);
 336
 337         slave = __eql_schedule_slaves(&eql->queue);
 338         if (slave) {
 339                 struct net_device *slave_dev = slave->dev;
 340
 341                 skb->dev = slave_dev;
 342                 skb->priority = 1;
 343                 slave->bytes_queued += skb->len;
 344                 dev_queue_xmit(skb);
 345                 dev->stats.tx_packets++;
 346         } else {
 347                 dev->stats.tx_dropped++;
 348                 dev_kfree_skb(skb);
 349         }
 350
 351         spin_unlock(&eql->queue.lock);
 352
 353         return NETDEV_TX_OK;
 354 }
 355
 356 /*
 357  *      Private ioctl functions
 358  */
 359
 360 /* queue->lock must be held */
 361 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
 362 {
 363         struct list_head *this, *head;
 364
 365         head = &queue->all_slaves;
 366         list_for_each(this, head) {
 367                 slave_t *slave = list_entry(this, slave_t, list);
 368
 369                 if (slave->dev == dev)
 370                         return slave;
 371         }
 372
 373         return NULL;
 374 }
 375
 376 static inline int eql_is_full(slave_queue_t *queue)
 377 {
 378         equalizer_t *eql = netdev_priv(queue->master_dev);
 379
 380         if (queue->num_slaves >= eql->max_slaves)
 381                 return 1;
 382         return 0;
 383 }
 384
 385 /* queue->lock must be held */
 386 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
 387 {
 388         if (!eql_is_full(queue)) {
 389                 slave_t *duplicate_slave = NULL;
 390
 391                 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
 392                 if (duplicate_slave)
 393                         eql_kill_one_slave(queue, duplicate_slave);
 394
 395                 list_add(&slave->list, &queue->all_slaves);
 396                 queue->num_slaves++;
 397                 slave->dev->flags |= IFF_SLAVE;
 398
 399                 return 0;
 400         }
 401
 402         return -ENOSPC;
 403 }
 404
 405 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
 406 {
 407         struct net_device *slave_dev;
 408         slaving_request_t srq;
 409
 410         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
 411                 return -EFAULT;
 412
 413         slave_dev  = dev_get_by_name(&init_net, srq.slave_name);
 414         if (slave_dev) {
 415                 if ((master_dev->flags & IFF_UP) == IFF_UP) {
 416                         /* slave is not a master & not already a slave: */
 417                         if (!eql_is_master(slave_dev) &&
 418                             !eql_is_slave(slave_dev)) {
 419                                 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
 420                                 equalizer_t *eql = netdev_priv(master_dev);
 421                                 int ret;
 422
 423                                 if (!s) {
 424                                         dev_put(slave_dev);
 425                                         return -ENOMEM;
 426                                 }
 427
 428                                 memset(s, 0, sizeof(*s));
 429                                 s->dev = slave_dev;
 430                                 s->priority = srq.priority;
 431                                 s->priority_bps = srq.priority;
 432                                 s->priority_Bps = srq.priority / 8;
 433
 434                                 spin_lock_bh(&eql->queue.lock);
 435                                 ret = __eql_insert_slave(&eql->queue, s);
 436                                 if (ret) {
 437                                         dev_put(slave_dev);
 438                                         kfree(s);
 439                                 }
 440                                 spin_unlock_bh(&eql->queue.lock);
 441
 442                                 return ret;
 443                         }
 444                 }
 445                 dev_put(slave_dev);
 446         }
 447
 448         return -EINVAL;
 449 }
 450
 451 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
 452 {
 453         equalizer_t *eql = netdev_priv(master_dev);
 454         struct net_device *slave_dev;
 455         slaving_request_t srq;
 456         int ret;
 457
 458         if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
 459                 return -EFAULT;
 460
 461         slave_dev = dev_get_by_name(&init_net, srq.slave_name);
 462         ret = -EINVAL;
 463         if (slave_dev) {
 464                 spin_lock_bh(&eql->queue.lock);
 465
 466                 if (eql_is_slave(slave_dev)) {
 467                         slave_t *slave = __eql_find_slave_dev(&eql->queue,
 468                                                               slave_dev);
 469
 470                         if (slave) {
 471                                 eql_kill_one_slave(&eql->queue, slave);
 472                                 ret = 0;
 473                         }
 474                 }
 475                 dev_put(slave_dev);
 476
 477                 spin_unlock_bh(&eql->queue.lock);
 478         }
 479
 480         return ret;
 481 }
 482
 483 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
 484 {
 485         equalizer_t *eql = netdev_priv(dev);
 486         slave_t *slave;
 487         struct net_device *slave_dev;
 488         slave_config_t sc;
 489         int ret;
 490
 491         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
 492                 return -EFAULT;
 493
 494         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
 495         if (!slave_dev)
 496                 return -ENODEV;
 497
 498         ret = -EINVAL;
 499
 500         spin_lock_bh(&eql->queue.lock);
 501         if (eql_is_slave(slave_dev)) {
 502                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
 503                 if (slave) {
 504                         sc.priority = slave->priority;
 505                         ret = 0;
 506                 }
 507         }
 508         spin_unlock_bh(&eql->queue.lock);
 509
 510         dev_put(slave_dev);
 511
 512         if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
 513                 ret = -EFAULT;
 514
 515         return ret;
 516 }
 517
 518 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
 519 {
 520         slave_t *slave;
 521         equalizer_t *eql;
 522         struct net_device *slave_dev;
 523         slave_config_t sc;
 524         int ret;
 525
 526         if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
 527                 return -EFAULT;
 528
 529         slave_dev = dev_get_by_name(&init_net, sc.slave_name);
 530         if (!slave_dev)
 531                 return -ENODEV;
 532
 533         ret = -EINVAL;
 534
 535         eql = netdev_priv(dev);
 536         spin_lock_bh(&eql->queue.lock);
 537         if (eql_is_slave(slave_dev)) {
 538                 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
 539                 if (slave) {
 540                         slave->priority = sc.priority;
 541                         slave->priority_bps = sc.priority;
 542                         slave->priority_Bps = sc.priority / 8;
 543                         ret = 0;
 544                 }
 545         }
 546         spin_unlock_bh(&eql->queue.lock);
 547
 548         dev_put(slave_dev);
 549
 550         return ret;
 551 }
 552
 553 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
 554 {
 555         equalizer_t *eql;
 556         master_config_t mc;
 557
 558         if (eql_is_master(dev)) {
 559                 eql = netdev_priv(dev);
 560                 mc.max_slaves = eql->max_slaves;
 561                 mc.min_slaves = eql->min_slaves;
 562                 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
 563                         return -EFAULT;
 564                 return 0;
 565         }
 566         return -EINVAL;
 567 }
 568
 569 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
 570 {
 571         equalizer_t *eql;
 572         master_config_t mc;
 573
 574         if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
 575                 return -EFAULT;
 576
 577         if (eql_is_master(dev)) {
 578                 eql = netdev_priv(dev);
 579                 eql->max_slaves = mc.max_slaves;
 580                 eql->min_slaves = mc.min_slaves;
 581                 return 0;
 582         }
 583         return -EINVAL;
 584 }
 585
 586 static struct net_device *dev_eql;
 587
 588 static int __init eql_init_module(void)
 589 {
 590         int err;
 591
 592         printk(version);
 593
 594         dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
 595         if (!dev_eql)
 596                 return -ENOMEM;
 597
 598         err = register_netdev(dev_eql);
 599         if (err)
 600                 free_netdev(dev_eql);
 601         return err;
 602 }
 603
 604 static void __exit eql_cleanup_module(void)
 605 {
 606         unregister_netdev(dev_eql);
 607         free_netdev(dev_eql);
 608 }
 609
 610 module_init(eql_init_module);
 611 module_exit(eql_cleanup_module);
 612 MODULE_LICENSE("GPL");