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/module.h> 115 #include <linux/kernel.h> 116 #include <linux/init.h> 117 #include <linux/timer.h> 118 #include <linux/netdevice.h> 119 120 #include <linux/if.h> 121 #include <linux/if_arp.h> 122 #include <linux/if_eql.h> 123 124 #include <asm/uaccess.h> 125 126 static int eql_open(struct net_device *dev); 127 static int eql_close(struct net_device *dev); 128 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); 129 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev); 130 static struct net_device_stats *eql_get_stats(struct net_device *dev); 131 132 #define eql_is_slave(dev) ((dev->flags & IFF_SLAVE) == IFF_SLAVE) 133 #define eql_is_master(dev) ((dev->flags & IFF_MASTER) == IFF_MASTER) 134 135 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave); 136 137 static void eql_timer(unsigned long param) 138 { 139 equalizer_t *eql = (equalizer_t *) param; 140 struct list_head *this, *tmp, *head; 141 142 spin_lock_bh(&eql->queue.lock); 143 head = &eql->queue.all_slaves; 144 list_for_each_safe(this, tmp, head) { 145 slave_t *slave = list_entry(this, slave_t, list); 146 147 if ((slave->dev->flags & IFF_UP) == IFF_UP) { 148 slave->bytes_queued -= slave->priority_Bps; 149 if (slave->bytes_queued < 0) 150 slave->bytes_queued = 0; 151 } else { 152 eql_kill_one_slave(&eql->queue, slave); 153 } 154 155 } 156 spin_unlock_bh(&eql->queue.lock); 157 158 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL; 159 add_timer(&eql->timer); 160 } 161 162 static char version[] __initdata = 163 "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n"; 164 165 static void __init eql_setup(struct net_device *dev) 166 { 167 equalizer_t *eql = netdev_priv(dev); 168 169 SET_MODULE_OWNER(dev); 170 171 init_timer(&eql->timer); 172 eql->timer.data = (unsigned long) eql; 173 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL; 174 eql->timer.function = eql_timer; 175 176 spin_lock_init(&eql->queue.lock); 177 INIT_LIST_HEAD(&eql->queue.all_slaves); 178 eql->queue.master_dev = dev; 179 180 dev->open = eql_open; 181 dev->stop = eql_close; 182 dev->do_ioctl = eql_ioctl; 183 dev->hard_start_xmit = eql_slave_xmit; 184 dev->get_stats = eql_get_stats; 185 186 /* 187 * Now we undo some of the things that eth_setup does 188 * that we don't like 189 */ 190 191 dev->mtu = EQL_DEFAULT_MTU; /* set to 576 in if_eql.h */ 192 dev->flags = IFF_MASTER; 193 194 dev->type = ARPHRD_SLIP; 195 dev->tx_queue_len = 5; /* Hands them off fast */ 196 } 197 198 static int eql_open(struct net_device *dev) 199 { 200 equalizer_t *eql = netdev_priv(dev); 201 202 /* XXX We should force this off automatically for the user. */ 203 printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on " 204 "your slave devices.\n", dev->name); 205 206 if (!list_empty(&eql->queue.all_slaves)) 207 BUG(); 208 209 eql->min_slaves = 1; 210 eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */ 211 212 add_timer(&eql->timer); 213 214 return 0; 215 } 216 217 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave) 218 { 219 list_del(&slave->list); 220 queue->num_slaves--; 221 slave->dev->flags &= ~IFF_SLAVE; 222 dev_put(slave->dev); 223 kfree(slave); 224 } 225 226 static void eql_kill_slave_queue(slave_queue_t *queue) 227 { 228 struct list_head *head, *tmp, *this; 229 230 spin_lock_bh(&queue->lock); 231 232 head = &queue->all_slaves; 233 list_for_each_safe(this, tmp, head) { 234 slave_t *s = list_entry(this, slave_t, list); 235 236 eql_kill_one_slave(queue, s); 237 } 238 239 spin_unlock_bh(&queue->lock); 240 } 241 242 static int eql_close(struct net_device *dev) 243 { 244 equalizer_t *eql = netdev_priv(dev); 245 246 /* 247 * The timer has to be stopped first before we start hacking away 248 * at the data structure it scans every so often... 249 */ 250 251 del_timer_sync(&eql->timer); 252 253 eql_kill_slave_queue(&eql->queue); 254 255 return 0; 256 } 257 258 static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq); 259 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq); 260 261 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc); 262 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc); 263 264 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc); 265 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc); 266 267 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 268 { 269 if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG && 270 !capable(CAP_NET_ADMIN)) 271 return -EPERM; 272 273 switch (cmd) { 274 case EQL_ENSLAVE: 275 return eql_enslave(dev, ifr->ifr_data); 276 case EQL_EMANCIPATE: 277 return eql_emancipate(dev, ifr->ifr_data); 278 case EQL_GETSLAVECFG: 279 return eql_g_slave_cfg(dev, ifr->ifr_data); 280 case EQL_SETSLAVECFG: 281 return eql_s_slave_cfg(dev, ifr->ifr_data); 282 case EQL_GETMASTRCFG: 283 return eql_g_master_cfg(dev, ifr->ifr_data); 284 case EQL_SETMASTRCFG: 285 return eql_s_master_cfg(dev, ifr->ifr_data); 286 default: 287 return -EOPNOTSUPP; 288 }; 289 } 290 291 /* queue->lock must be held */ 292 static slave_t *__eql_schedule_slaves(slave_queue_t *queue) 293 { 294 unsigned long best_load = ~0UL; 295 struct list_head *this, *tmp, *head; 296 slave_t *best_slave; 297 298 best_slave = NULL; 299 300 /* Make a pass to set the best slave. */ 301 head = &queue->all_slaves; 302 list_for_each_safe(this, tmp, head) { 303 slave_t *slave = list_entry(this, slave_t, list); 304 unsigned long slave_load, bytes_queued, priority_Bps; 305 306 /* Go through the slave list once, updating best_slave 307 * whenever a new best_load is found. 308 */ 309 bytes_queued = slave->bytes_queued; 310 priority_Bps = slave->priority_Bps; 311 if ((slave->dev->flags & IFF_UP) == IFF_UP) { 312 slave_load = (~0UL - (~0UL / 2)) - 313 (priority_Bps) + bytes_queued * 8; 314 315 if (slave_load < best_load) { 316 best_load = slave_load; 317 best_slave = slave; 318 } 319 } else { 320 /* We found a dead slave, kill it. */ 321 eql_kill_one_slave(queue, slave); 322 } 323 } 324 return best_slave; 325 } 326 327 static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev) 328 { 329 equalizer_t *eql = netdev_priv(dev); 330 slave_t *slave; 331 332 spin_lock(&eql->queue.lock); 333 334 slave = __eql_schedule_slaves(&eql->queue); 335 if (slave) { 336 struct net_device *slave_dev = slave->dev; 337 338 skb->dev = slave_dev; 339 skb->priority = 1; 340 slave->bytes_queued += skb->len; 341 dev_queue_xmit(skb); 342 eql->stats.tx_packets++; 343 } else { 344 eql->stats.tx_dropped++; 345 dev_kfree_skb(skb); 346 } 347 348 spin_unlock(&eql->queue.lock); 349 350 return 0; 351 } 352 353 static struct net_device_stats * eql_get_stats(struct net_device *dev) 354 { 355 equalizer_t *eql = netdev_priv(dev); 356 return &eql->stats; 357 } 358 359 /* 360 * Private ioctl functions 361 */ 362 363 /* queue->lock must be held */ 364 static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev) 365 { 366 struct list_head *this, *head; 367 368 head = &queue->all_slaves; 369 list_for_each(this, head) { 370 slave_t *slave = list_entry(this, slave_t, list); 371 372 if (slave->dev == dev) 373 return slave; 374 } 375 376 return NULL; 377 } 378 379 static inline int eql_is_full(slave_queue_t *queue) 380 { 381 equalizer_t *eql = netdev_priv(queue->master_dev); 382 383 if (queue->num_slaves >= eql->max_slaves) 384 return 1; 385 return 0; 386 } 387 388 /* queue->lock must be held */ 389 static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave) 390 { 391 if (!eql_is_full(queue)) { 392 slave_t *duplicate_slave = NULL; 393 394 duplicate_slave = __eql_find_slave_dev(queue, slave->dev); 395 if (duplicate_slave != 0) 396 eql_kill_one_slave(queue, duplicate_slave); 397 398 list_add(&slave->list, &queue->all_slaves); 399 queue->num_slaves++; 400 slave->dev->flags |= IFF_SLAVE; 401 402 return 0; 403 } 404 405 return -ENOSPC; 406 } 407 408 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp) 409 { 410 struct net_device *slave_dev; 411 slaving_request_t srq; 412 413 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t))) 414 return -EFAULT; 415 416 slave_dev = dev_get_by_name(srq.slave_name); 417 if (slave_dev) { 418 if ((master_dev->flags & IFF_UP) == IFF_UP) { 419 /* slave is not a master & not already a slave: */ 420 if (!eql_is_master(slave_dev) && 421 !eql_is_slave(slave_dev)) { 422 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL); 423 equalizer_t *eql = netdev_priv(master_dev); 424 int ret; 425 426 if (!s) { 427 dev_put(slave_dev); 428 return -ENOMEM; 429 } 430 431 memset(s, 0, sizeof(*s)); 432 s->dev = slave_dev; 433 s->priority = srq.priority; 434 s->priority_bps = srq.priority; 435 s->priority_Bps = srq.priority / 8; 436 437 spin_lock_bh(&eql->queue.lock); 438 ret = __eql_insert_slave(&eql->queue, s); 439 if (ret) { 440 dev_put(slave_dev); 441 kfree(s); 442 } 443 spin_unlock_bh(&eql->queue.lock); 444 445 return ret; 446 } 447 } 448 dev_put(slave_dev); 449 } 450 451 return -EINVAL; 452 } 453 454 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp) 455 { 456 equalizer_t *eql = netdev_priv(master_dev); 457 struct net_device *slave_dev; 458 slaving_request_t srq; 459 int ret; 460 461 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t))) 462 return -EFAULT; 463 464 slave_dev = dev_get_by_name(srq.slave_name); 465 ret = -EINVAL; 466 if (slave_dev) { 467 spin_lock_bh(&eql->queue.lock); 468 469 if (eql_is_slave(slave_dev)) { 470 slave_t *slave = __eql_find_slave_dev(&eql->queue, 471 slave_dev); 472 473 if (slave) { 474 eql_kill_one_slave(&eql->queue, slave); 475 ret = 0; 476 } 477 } 478 dev_put(slave_dev); 479 480 spin_unlock_bh(&eql->queue.lock); 481 } 482 483 return ret; 484 } 485 486 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp) 487 { 488 equalizer_t *eql = netdev_priv(dev); 489 slave_t *slave; 490 struct net_device *slave_dev; 491 slave_config_t sc; 492 int ret; 493 494 if (copy_from_user(&sc, scp, sizeof (slave_config_t))) 495 return -EFAULT; 496 497 slave_dev = dev_get_by_name(sc.slave_name); 498 if (!slave_dev) 499 return -ENODEV; 500 501 ret = -EINVAL; 502 503 spin_lock_bh(&eql->queue.lock); 504 if (eql_is_slave(slave_dev)) { 505 slave = __eql_find_slave_dev(&eql->queue, slave_dev); 506 if (slave) { 507 sc.priority = slave->priority; 508 ret = 0; 509 } 510 } 511 spin_unlock_bh(&eql->queue.lock); 512 513 dev_put(slave_dev); 514 515 if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t))) 516 ret = -EFAULT; 517 518 return ret; 519 } 520 521 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp) 522 { 523 slave_t *slave; 524 equalizer_t *eql; 525 struct net_device *slave_dev; 526 slave_config_t sc; 527 int ret; 528 529 if (copy_from_user(&sc, scp, sizeof (slave_config_t))) 530 return -EFAULT; 531 532 slave_dev = dev_get_by_name(sc.slave_name); 533 if (!slave_dev) 534 return -ENODEV; 535 536 ret = -EINVAL; 537 538 eql = netdev_priv(dev); 539 spin_lock_bh(&eql->queue.lock); 540 if (eql_is_slave(slave_dev)) { 541 slave = __eql_find_slave_dev(&eql->queue, slave_dev); 542 if (slave) { 543 slave->priority = sc.priority; 544 slave->priority_bps = sc.priority; 545 slave->priority_Bps = sc.priority / 8; 546 ret = 0; 547 } 548 } 549 spin_unlock_bh(&eql->queue.lock); 550 551 return ret; 552 } 553 554 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp) 555 { 556 equalizer_t *eql; 557 master_config_t mc; 558 559 if (eql_is_master(dev)) { 560 eql = netdev_priv(dev); 561 mc.max_slaves = eql->max_slaves; 562 mc.min_slaves = eql->min_slaves; 563 if (copy_to_user(mcp, &mc, sizeof (master_config_t))) 564 return -EFAULT; 565 return 0; 566 } 567 return -EINVAL; 568 } 569 570 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp) 571 { 572 equalizer_t *eql; 573 master_config_t mc; 574 575 if (copy_from_user(&mc, mcp, sizeof (master_config_t))) 576 return -EFAULT; 577 578 if (eql_is_master(dev)) { 579 eql = netdev_priv(dev); 580 eql->max_slaves = mc.max_slaves; 581 eql->min_slaves = mc.min_slaves; 582 return 0; 583 } 584 return -EINVAL; 585 } 586 587 static struct net_device *dev_eql; 588 589 static int __init eql_init_module(void) 590 { 591 int err; 592 593 printk(version); 594 595 dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup); 596 if (!dev_eql) 597 return -ENOMEM; 598 599 err = register_netdev(dev_eql); 600 if (err) 601 free_netdev(dev_eql); 602 return err; 603 } 604 605 static void __exit eql_cleanup_module(void) 606 { 607 unregister_netdev(dev_eql); 608 free_netdev(dev_eql); 609 } 610 611 module_init(eql_init_module); 612 module_exit(eql_cleanup_module); 613 MODULE_LICENSE("GPL"); 614