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 <linux/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(struct timer_list *t) 143 { 144 equalizer_t *eql = from_timer(eql, t, timer); 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 timer_setup(&eql->timer, eql_timer, 0); 182 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL; 183 184 spin_lock_init(&eql->queue.lock); 185 INIT_LIST_HEAD(&eql->queue.all_slaves); 186 eql->queue.master_dev = dev; 187 188 dev->netdev_ops = &eql_netdev_ops; 189 190 /* 191 * Now we undo some of the things that eth_setup does 192 * that we don't like 193 */ 194 195 dev->mtu = EQL_DEFAULT_MTU; /* set to 576 in if_eql.h */ 196 dev->flags = IFF_MASTER; 197 198 dev->type = ARPHRD_SLIP; 199 dev->tx_queue_len = 5; /* Hands them off fast */ 200 netif_keep_dst(dev); 201 } 202 203 static int eql_open(struct net_device *dev) 204 { 205 equalizer_t *eql = netdev_priv(dev); 206 207 /* XXX We should force this off automatically for the user. */ 208 netdev_info(dev, 209 "remember to turn off Van-Jacobson compression on your slave devices\n"); 210 211 BUG_ON(!list_empty(&eql->queue.all_slaves)); 212 213 eql->min_slaves = 1; 214 eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */ 215 216 add_timer(&eql->timer); 217 218 return 0; 219 } 220 221 static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave) 222 { 223 list_del(&slave->list); 224 queue->num_slaves--; 225 slave->dev->flags &= ~IFF_SLAVE; 226 dev_put(slave->dev); 227 kfree(slave); 228 } 229 230 static void eql_kill_slave_queue(slave_queue_t *queue) 231 { 232 struct list_head *head, *tmp, *this; 233 234 spin_lock_bh(&queue->lock); 235 236 head = &queue->all_slaves; 237 list_for_each_safe(this, tmp, head) { 238 slave_t *s = list_entry(this, slave_t, list); 239 240 eql_kill_one_slave(queue, s); 241 } 242 243 spin_unlock_bh(&queue->lock); 244 } 245 246 static int eql_close(struct net_device *dev) 247 { 248 equalizer_t *eql = netdev_priv(dev); 249 250 /* 251 * The timer has to be stopped first before we start hacking away 252 * at the data structure it scans every so often... 253 */ 254 255 del_timer_sync(&eql->timer); 256 257 eql_kill_slave_queue(&eql->queue); 258 259 return 0; 260 } 261 262 static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq); 263 static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq); 264 265 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc); 266 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc); 267 268 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc); 269 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc); 270 271 static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 272 { 273 if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG && 274 !capable(CAP_NET_ADMIN)) 275 return -EPERM; 276 277 switch (cmd) { 278 case EQL_ENSLAVE: 279 return eql_enslave(dev, ifr->ifr_data); 280 case EQL_EMANCIPATE: 281 return eql_emancipate(dev, ifr->ifr_data); 282 case EQL_GETSLAVECFG: 283 return eql_g_slave_cfg(dev, ifr->ifr_data); 284 case EQL_SETSLAVECFG: 285 return eql_s_slave_cfg(dev, ifr->ifr_data); 286 case EQL_GETMASTRCFG: 287 return eql_g_master_cfg(dev, ifr->ifr_data); 288 case EQL_SETMASTRCFG: 289 return eql_s_master_cfg(dev, ifr->ifr_data); 290 default: 291 return -EOPNOTSUPP; 292 } 293 } 294 295 /* queue->lock must be held */ 296 static slave_t *__eql_schedule_slaves(slave_queue_t *queue) 297 { 298 unsigned long best_load = ~0UL; 299 struct list_head *this, *tmp, *head; 300 slave_t *best_slave; 301 302 best_slave = NULL; 303 304 /* Make a pass to set the best slave. */ 305 head = &queue->all_slaves; 306 list_for_each_safe(this, tmp, head) { 307 slave_t *slave = list_entry(this, slave_t, list); 308 unsigned long slave_load, bytes_queued, priority_Bps; 309 310 /* Go through the slave list once, updating best_slave 311 * whenever a new best_load is found. 312 */ 313 bytes_queued = slave->bytes_queued; 314 priority_Bps = slave->priority_Bps; 315 if ((slave->dev->flags & IFF_UP) == IFF_UP) { 316 slave_load = (~0UL - (~0UL / 2)) - 317 (priority_Bps) + bytes_queued * 8; 318 319 if (slave_load < best_load) { 320 best_load = slave_load; 321 best_slave = slave; 322 } 323 } else { 324 /* We found a dead slave, kill it. */ 325 eql_kill_one_slave(queue, slave); 326 } 327 } 328 return best_slave; 329 } 330 331 static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev) 332 { 333 equalizer_t *eql = netdev_priv(dev); 334 slave_t *slave; 335 336 spin_lock(&eql->queue.lock); 337 338 slave = __eql_schedule_slaves(&eql->queue); 339 if (slave) { 340 struct net_device *slave_dev = slave->dev; 341 342 skb->dev = slave_dev; 343 skb->priority = TC_PRIO_FILLER; 344 slave->bytes_queued += skb->len; 345 dev_queue_xmit(skb); 346 dev->stats.tx_packets++; 347 } else { 348 dev->stats.tx_dropped++; 349 dev_kfree_skb(skb); 350 } 351 352 spin_unlock(&eql->queue.lock); 353 354 return NETDEV_TX_OK; 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 dev_hold(slave->dev); 397 list_add(&slave->list, &queue->all_slaves); 398 queue->num_slaves++; 399 slave->dev->flags |= IFF_SLAVE; 400 401 return 0; 402 } 403 404 return -ENOSPC; 405 } 406 407 static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp) 408 { 409 struct net_device *slave_dev; 410 slaving_request_t srq; 411 412 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t))) 413 return -EFAULT; 414 415 slave_dev = __dev_get_by_name(&init_net, srq.slave_name); 416 if (!slave_dev) 417 return -ENODEV; 418 419 if ((master_dev->flags & IFF_UP) == IFF_UP) { 420 /* slave is not a master & not already a slave: */ 421 if (!eql_is_master(slave_dev) && !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 return -ENOMEM; 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 kfree(s); 439 440 spin_unlock_bh(&eql->queue.lock); 441 442 return ret; 443 } 444 } 445 446 return -EINVAL; 447 } 448 449 static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp) 450 { 451 equalizer_t *eql = netdev_priv(master_dev); 452 struct net_device *slave_dev; 453 slaving_request_t srq; 454 int ret; 455 456 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t))) 457 return -EFAULT; 458 459 slave_dev = __dev_get_by_name(&init_net, srq.slave_name); 460 if (!slave_dev) 461 return -ENODEV; 462 463 ret = -EINVAL; 464 spin_lock_bh(&eql->queue.lock); 465 if (eql_is_slave(slave_dev)) { 466 slave_t *slave = __eql_find_slave_dev(&eql->queue, slave_dev); 467 if (slave) { 468 eql_kill_one_slave(&eql->queue, slave); 469 ret = 0; 470 } 471 } 472 spin_unlock_bh(&eql->queue.lock); 473 474 return ret; 475 } 476 477 static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp) 478 { 479 equalizer_t *eql = netdev_priv(dev); 480 slave_t *slave; 481 struct net_device *slave_dev; 482 slave_config_t sc; 483 int ret; 484 485 if (copy_from_user(&sc, scp, sizeof (slave_config_t))) 486 return -EFAULT; 487 488 slave_dev = __dev_get_by_name(&init_net, sc.slave_name); 489 if (!slave_dev) 490 return -ENODEV; 491 492 ret = -EINVAL; 493 494 spin_lock_bh(&eql->queue.lock); 495 if (eql_is_slave(slave_dev)) { 496 slave = __eql_find_slave_dev(&eql->queue, slave_dev); 497 if (slave) { 498 sc.priority = slave->priority; 499 ret = 0; 500 } 501 } 502 spin_unlock_bh(&eql->queue.lock); 503 504 if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t))) 505 ret = -EFAULT; 506 507 return ret; 508 } 509 510 static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp) 511 { 512 slave_t *slave; 513 equalizer_t *eql; 514 struct net_device *slave_dev; 515 slave_config_t sc; 516 int ret; 517 518 if (copy_from_user(&sc, scp, sizeof (slave_config_t))) 519 return -EFAULT; 520 521 slave_dev = __dev_get_by_name(&init_net, sc.slave_name); 522 if (!slave_dev) 523 return -ENODEV; 524 525 ret = -EINVAL; 526 527 eql = netdev_priv(dev); 528 spin_lock_bh(&eql->queue.lock); 529 if (eql_is_slave(slave_dev)) { 530 slave = __eql_find_slave_dev(&eql->queue, slave_dev); 531 if (slave) { 532 slave->priority = sc.priority; 533 slave->priority_bps = sc.priority; 534 slave->priority_Bps = sc.priority / 8; 535 ret = 0; 536 } 537 } 538 spin_unlock_bh(&eql->queue.lock); 539 540 return ret; 541 } 542 543 static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp) 544 { 545 equalizer_t *eql; 546 master_config_t mc; 547 548 memset(&mc, 0, sizeof(master_config_t)); 549 550 if (eql_is_master(dev)) { 551 eql = netdev_priv(dev); 552 mc.max_slaves = eql->max_slaves; 553 mc.min_slaves = eql->min_slaves; 554 if (copy_to_user(mcp, &mc, sizeof (master_config_t))) 555 return -EFAULT; 556 return 0; 557 } 558 return -EINVAL; 559 } 560 561 static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp) 562 { 563 equalizer_t *eql; 564 master_config_t mc; 565 566 if (copy_from_user(&mc, mcp, sizeof (master_config_t))) 567 return -EFAULT; 568 569 if (eql_is_master(dev)) { 570 eql = netdev_priv(dev); 571 eql->max_slaves = mc.max_slaves; 572 eql->min_slaves = mc.min_slaves; 573 return 0; 574 } 575 return -EINVAL; 576 } 577 578 static struct net_device *dev_eql; 579 580 static int __init eql_init_module(void) 581 { 582 int err; 583 584 pr_info("%s\n", version); 585 586 dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", NET_NAME_UNKNOWN, 587 eql_setup); 588 if (!dev_eql) 589 return -ENOMEM; 590 591 err = register_netdev(dev_eql); 592 if (err) 593 free_netdev(dev_eql); 594 return err; 595 } 596 597 static void __exit eql_cleanup_module(void) 598 { 599 unregister_netdev(dev_eql); 600 free_netdev(dev_eql); 601 } 602 603 module_init(eql_init_module); 604 module_exit(eql_cleanup_module); 605 MODULE_LICENSE("GPL"); 606