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