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