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 129static int eql_open(struct net_device *dev); 130static int eql_close(struct net_device *dev); 131static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd); 132static 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 137static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave); 138 139static 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 164static const char version[] __initconst = 165 "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n"; 166 167static 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 174static 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 202static int eql_open(struct net_device *dev) 203{ 204 equalizer_t *eql = netdev_priv(dev); 205 206 printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on " 207 "your slave devices.\n", dev->name); 208 209 BUG_ON(!list_empty(&eql->queue.all_slaves)); 210 211 eql->min_slaves = 1; 212 eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */ 213 214 add_timer(&eql->timer); 215 216 return 0; 217} 218 219static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave) 220{ 221 list_del(&slave->list); 222 queue->num_slaves--; 223 slave->dev->flags &= ~IFF_SLAVE; 224 dev_put(slave->dev); 225 kfree(slave); 226} 227 228static void eql_kill_slave_queue(slave_queue_t *queue) 229{ 230 struct list_head *head, *tmp, *this; 231 232 spin_lock_bh(&queue->lock); 233 234 head = &queue->all_slaves; 235 list_for_each_safe(this, tmp, head) { 236 slave_t *s = list_entry(this, slave_t, list); 237 238 eql_kill_one_slave(queue, s); 239 } 240 241 spin_unlock_bh(&queue->lock); 242} 243 244static int eql_close(struct net_device *dev) 245{ 246 equalizer_t *eql = netdev_priv(dev); 247 248 /* 249 * The timer has to be stopped first before we start hacking away 250 * at the data structure it scans every so often... 251 */ 252 253 del_timer_sync(&eql->timer); 254 255 eql_kill_slave_queue(&eql->queue); 256 257 return 0; 258} 259 260static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq); 261static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq); 262 263static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc); 264static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc); 265 266static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc); 267static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc); 268 269static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 270{ 271 if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG && 272 !capable(CAP_NET_ADMIN)) 273 return -EPERM; 274 275 switch (cmd) { 276 case EQL_ENSLAVE: 277 return eql_enslave(dev, ifr->ifr_data); 278 case EQL_EMANCIPATE: 279 return eql_emancipate(dev, ifr->ifr_data); 280 case EQL_GETSLAVECFG: 281 return eql_g_slave_cfg(dev, ifr->ifr_data); 282 case EQL_SETSLAVECFG: 283 return eql_s_slave_cfg(dev, ifr->ifr_data); 284 case EQL_GETMASTRCFG: 285 return eql_g_master_cfg(dev, ifr->ifr_data); 286 case EQL_SETMASTRCFG: 287 return eql_s_master_cfg(dev, ifr->ifr_data); 288 default: 289 return -EOPNOTSUPP; 290 } 291} 292 293/* queue->lock must be held */ 294static slave_t *__eql_schedule_slaves(slave_queue_t *queue) 295{ 296 unsigned long best_load = ~0UL; 297 struct list_head *this, *tmp, *head; 298 slave_t *best_slave; 299 300 best_slave = NULL; 301 302 /* Make a pass to set the best slave. */ 303 head = &queue->all_slaves; 304 list_for_each_safe(this, tmp, head) { 305 slave_t *slave = list_entry(this, slave_t, list); 306 unsigned long slave_load, bytes_queued, priority_Bps; 307 308 /* Go through the slave list once, updating best_slave 309 * whenever a new best_load is found. 310 */ 311 bytes_queued = slave->bytes_queued; 312 priority_Bps = slave->priority_Bps; 313 if ((slave->dev->flags & IFF_UP) == IFF_UP) { 314 slave_load = (~0UL - (~0UL / 2)) - 315 (priority_Bps) + bytes_queued * 8; 316 317 if (slave_load < best_load) { 318 best_load = slave_load; 319 best_slave = slave; 320 } 321 } else { 322 /* We found a dead slave, kill it. */ 323 eql_kill_one_slave(queue, slave); 324 } 325 } 326 return best_slave; 327} 328 329static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev) 330{ 331 equalizer_t *eql = netdev_priv(dev); 332 slave_t *slave; 333 334 spin_lock(&eql->queue.lock); 335 336 slave = __eql_schedule_slaves(&eql->queue); 337 if (slave) { 338 struct net_device *slave_dev = slave->dev; 339 340 skb->dev = slave_dev; 341 skb->priority = 1; 342 slave->bytes_queued += skb->len; 343 dev_queue_xmit(skb); 344 dev->stats.tx_packets++; 345 } else { 346 dev->stats.tx_dropped++; 347 dev_kfree_skb(skb); 348 } 349 350 spin_unlock(&eql->queue.lock); 351 352 return NETDEV_TX_OK; 353} 354 355/* 356 * Private ioctl functions 357 */ 358 359/* queue->lock must be held */ 360static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev) 361{ 362 struct list_head *this, *head; 363 364 head = &queue->all_slaves; 365 list_for_each(this, head) { 366 slave_t *slave = list_entry(this, slave_t, list); 367 368 if (slave->dev == dev) 369 return slave; 370 } 371 372 return NULL; 373} 374 375static inline int eql_is_full(slave_queue_t *queue) 376{ 377 equalizer_t *eql = netdev_priv(queue->master_dev); 378 379 if (queue->num_slaves >= eql->max_slaves) 380 return 1; 381 return 0; 382} 383 384/* queue->lock must be held */ 385static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave) 386{ 387 if (!eql_is_full(queue)) { 388 slave_t *duplicate_slave = NULL; 389 390 duplicate_slave = __eql_find_slave_dev(queue, slave->dev); 391 if (duplicate_slave) 392 eql_kill_one_slave(queue, duplicate_slave); 393 394 list_add(&slave->list, &queue->all_slaves); 395 queue->num_slaves++; 396 slave->dev->flags |= IFF_SLAVE; 397 398 return 0; 399 } 400 401 return -ENOSPC; 402} 403 404static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp) 405{ 406 struct net_device *slave_dev; 407 slaving_request_t srq; 408 409 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t))) 410 return -EFAULT; 411 412 slave_dev = dev_get_by_name(&init_net, srq.slave_name); 413 if (slave_dev) { 414 if ((master_dev->flags & IFF_UP) == IFF_UP) { 415 /* slave is not a master & not already a slave: */ 416 if (!eql_is_master(slave_dev) && 417 !eql_is_slave(slave_dev)) { 418 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL); 419 equalizer_t *eql = netdev_priv(master_dev); 420 int ret; 421 422 if (!s) { 423 dev_put(slave_dev); 424 return -ENOMEM; 425 } 426 427 memset(s, 0, sizeof(*s)); 428 s->dev = slave_dev; 429 s->priority = srq.priority; 430 s->priority_bps = srq.priority; 431 s->priority_Bps = srq.priority / 8; 432 433 spin_lock_bh(&eql->queue.lock); 434 ret = __eql_insert_slave(&eql->queue, s); 435 if (ret) { 436 dev_put(slave_dev); 437 kfree(s); 438 } 439 spin_unlock_bh(&eql->queue.lock); 440 441 return ret; 442 } 443 } 444 dev_put(slave_dev); 445 } 446 447 return -EINVAL; 448} 449 450static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp) 451{ 452 equalizer_t *eql = netdev_priv(master_dev); 453 struct net_device *slave_dev; 454 slaving_request_t srq; 455 int ret; 456 457 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t))) 458 return -EFAULT; 459 460 slave_dev = dev_get_by_name(&init_net, srq.slave_name); 461 ret = -EINVAL; 462 if (slave_dev) { 463 spin_lock_bh(&eql->queue.lock); 464 465 if (eql_is_slave(slave_dev)) { 466 slave_t *slave = __eql_find_slave_dev(&eql->queue, 467 slave_dev); 468 469 if (slave) { 470 eql_kill_one_slave(&eql->queue, slave); 471 ret = 0; 472 } 473 } 474 dev_put(slave_dev); 475 476 spin_unlock_bh(&eql->queue.lock); 477 } 478 479 return ret; 480} 481 482static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp) 483{ 484 equalizer_t *eql = netdev_priv(dev); 485 slave_t *slave; 486 struct net_device *slave_dev; 487 slave_config_t sc; 488 int ret; 489 490 if (copy_from_user(&sc, scp, sizeof (slave_config_t))) 491 return -EFAULT; 492 493 slave_dev = dev_get_by_name(&init_net, sc.slave_name); 494 if (!slave_dev) 495 return -ENODEV; 496 497 ret = -EINVAL; 498 499 spin_lock_bh(&eql->queue.lock); 500 if (eql_is_slave(slave_dev)) { 501 slave = __eql_find_slave_dev(&eql->queue, slave_dev); 502 if (slave) { 503 sc.priority = slave->priority; 504 ret = 0; 505 } 506 } 507 spin_unlock_bh(&eql->queue.lock); 508 509 dev_put(slave_dev); 510 511 if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t))) 512 ret = -EFAULT; 513 514 return ret; 515} 516 517static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp) 518{ 519 slave_t *slave; 520 equalizer_t *eql; 521 struct net_device *slave_dev; 522 slave_config_t sc; 523 int ret; 524 525 if (copy_from_user(&sc, scp, sizeof (slave_config_t))) 526 return -EFAULT; 527 528 slave_dev = dev_get_by_name(&init_net, sc.slave_name); 529 if (!slave_dev) 530 return -ENODEV; 531 532 ret = -EINVAL; 533 534 eql = netdev_priv(dev); 535 spin_lock_bh(&eql->queue.lock); 536 if (eql_is_slave(slave_dev)) { 537 slave = __eql_find_slave_dev(&eql->queue, slave_dev); 538 if (slave) { 539 slave->priority = sc.priority; 540 slave->priority_bps = sc.priority; 541 slave->priority_Bps = sc.priority / 8; 542 ret = 0; 543 } 544 } 545 spin_unlock_bh(&eql->queue.lock); 546 547 dev_put(slave_dev); 548 549 return ret; 550} 551 552static 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 memset(&mc, 0, sizeof(master_config_t)); 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 570static 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 587static struct net_device *dev_eql; 588 589static 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 605static void __exit eql_cleanup_module(void) 606{ 607 unregister_netdev(dev_eql); 608 free_netdev(dev_eql); 609} 610 611module_init(eql_init_module); 612module_exit(eql_cleanup_module); 613MODULE_LICENSE("GPL"); 614