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1/*2 * Equalizer Load-balancer for serial network interfaces.3 *4 * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes5 * 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 terms10 * of the GNU General Public License, incorporated herein by reference.11 *12 * The author may be reached as simon@ncm.com, or C/O13 * NCM14 * Attn: Simon Janes15 * 6803 Whittier Ave16 * McLean VA 2210117 * Phone: 1-703-847-0040 ext 10318 */19 20/*21 * Sources:22 * skeleton.c by Donald Becker.23 * Inspirations:24 * The Harried and Overworked Alan Cox25 * 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 guru33 * Added one-line eql_remove_slave patch.34 *35 * Revision 1.1 1996/04/11 17:44:17 guru36 * Initial revision37 *38 * Revision 3.13 1996/01/21 15:17:18 alan39 * tx_queue_len changes.40 * reformatted.41 *42 * Revision 3.12 1995/03/22 21:07:51 anarchy43 * Added capable() checks on configuration.44 * Moved header file.45 *46 * Revision 3.11 1995/01/19 23:14:31 guru47 * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -48 * (priority_Bps) + bytes_queued * 8;49 *50 * Revision 3.10 1995/01/19 23:07:53 guru51 * back to52 * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -53 * (priority_Bps) + bytes_queued;54 *55 * Revision 3.9 1995/01/19 22:38:20 guru56 * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -57 * (priority_Bps) + bytes_queued * 4;58 *59 * Revision 3.8 1995/01/19 22:30:55 guru60 * slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -61 * (priority_Bps) + bytes_queued * 2;62 *63 * Revision 3.7 1995/01/19 21:52:35 guru64 * printk's trimmed out.65 *66 * Revision 3.6 1995/01/19 21:49:56 guru67 * This is working pretty well. I gained 1 K/s in speed.. now it's just68 * robustness and printk's to be diked out.69 *70 * Revision 3.5 1995/01/18 22:29:59 guru71 * still crashes the kernel when the lock_wait thing is woken up.72 *73 * Revision 3.4 1995/01/18 21:59:47 guru74 * Broken set-bit locking snapshot75 *76 * Revision 3.3 1995/01/17 22:09:18 guru77 * infinite sleep in a lock somewhere..78 *79 * Revision 3.2 1995/01/15 16:46:06 guru80 * Log trimmed of non-pertinent 1.x branch messages81 *82 * Revision 3.1 1995/01/15 14:41:45 guru83 * New Scheduler and timer stuff...84 *85 * Revision 1.15 1995/01/15 14:29:02 guru86 * Will make 1.14 (now 1.15) the 3.0 branch, and the 1.12 the 2.0 branch, the one87 * with the dumber scheduler88 *89 * Revision 1.14 1995/01/15 02:37:08 guru90 * shock.. the kept-new-versions could have zonked working91 * stuff.. shudder92 *93 * Revision 1.13 1995/01/15 02:36:31 guru94 * big changes95 *96 * scheduler was torn out and replaced with something smarter97 *98 * global names not prefixed with eql_ were renamed to protect99 * against namespace collisions100 *101 * a few more abstract interfaces were added to facilitate any102 * potential change of datastructure. the driver is still using103 * a linked list of slaves. going to a heap would be a bit of104 * 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 otherwise110 *111 * Sorry, I had to rewrite most of this for 2.5.x -DaveM112 */113 114#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt115 116#include <linux/compat.h>117#include <linux/capability.h>118#include <linux/module.h>119#include <linux/kernel.h>120#include <linux/init.h>121#include <linux/slab.h>122#include <linux/timer.h>123#include <linux/netdevice.h>124#include <net/net_namespace.h>125 126#include <linux/if.h>127#include <linux/if_arp.h>128#include <linux/if_eql.h>129#include <linux/pkt_sched.h>130 131#include <linux/uaccess.h>132 133static int eql_open(struct net_device *dev);134static int eql_close(struct net_device *dev);135static int eql_siocdevprivate(struct net_device *dev, struct ifreq *ifr,136 void __user *data, int cmd);137static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);138 139#define eql_is_slave(dev) ((dev->flags & IFF_SLAVE) == IFF_SLAVE)140#define eql_is_master(dev) ((dev->flags & IFF_MASTER) == IFF_MASTER)141 142static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);143 144static void eql_timer(struct timer_list *t)145{146 equalizer_t *eql = from_timer(eql, t, timer);147 struct list_head *this, *tmp, *head;148 149 spin_lock(&eql->queue.lock);150 head = &eql->queue.all_slaves;151 list_for_each_safe(this, tmp, head) {152 slave_t *slave = list_entry(this, slave_t, list);153 154 if ((slave->dev->flags & IFF_UP) == IFF_UP) {155 slave->bytes_queued -= slave->priority_Bps;156 if (slave->bytes_queued < 0)157 slave->bytes_queued = 0;158 } else {159 eql_kill_one_slave(&eql->queue, slave);160 }161 162 }163 spin_unlock(&eql->queue.lock);164 165 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;166 add_timer(&eql->timer);167}168 169static const char version[] __initconst =170 "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)";171 172static const struct net_device_ops eql_netdev_ops = {173 .ndo_open = eql_open,174 .ndo_stop = eql_close,175 .ndo_siocdevprivate = eql_siocdevprivate,176 .ndo_start_xmit = eql_slave_xmit,177};178 179static void __init eql_setup(struct net_device *dev)180{181 equalizer_t *eql = netdev_priv(dev);182 183 timer_setup(&eql->timer, eql_timer, 0);184 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;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 does194 * that we don't like195 */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 netif_keep_dst(dev);203}204 205static 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 223static 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 netdev_put(slave->dev, &slave->dev_tracker);229 kfree(slave);230}231 232static 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 248static 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 away254 * 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 264static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq);265static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);266 267static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);268static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);269 270static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);271static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);272 273static int eql_siocdevprivate(struct net_device *dev, struct ifreq *ifr,274 void __user *data, int cmd)275{276 if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&277 !capable(CAP_NET_ADMIN))278 return -EPERM;279 280 if (in_compat_syscall()) /* to be implemented */281 return -EOPNOTSUPP;282 283 switch (cmd) {284 case EQL_ENSLAVE:285 return eql_enslave(dev, data);286 case EQL_EMANCIPATE:287 return eql_emancipate(dev, data);288 case EQL_GETSLAVECFG:289 return eql_g_slave_cfg(dev, data);290 case EQL_SETSLAVECFG:291 return eql_s_slave_cfg(dev, data);292 case EQL_GETMASTRCFG:293 return eql_g_master_cfg(dev, data);294 case EQL_SETMASTRCFG:295 return eql_s_master_cfg(dev, data);296 default:297 return -EOPNOTSUPP;298 }299}300 301/* queue->lock must be held */302static slave_t *__eql_schedule_slaves(slave_queue_t *queue)303{304 unsigned long best_load = ~0UL;305 struct list_head *this, *tmp, *head;306 slave_t *best_slave;307 308 best_slave = NULL;309 310 /* Make a pass to set the best slave. */311 head = &queue->all_slaves;312 list_for_each_safe(this, tmp, head) {313 slave_t *slave = list_entry(this, slave_t, list);314 unsigned long slave_load, bytes_queued, priority_Bps;315 316 /* Go through the slave list once, updating best_slave317 * whenever a new best_load is found.318 */319 bytes_queued = slave->bytes_queued;320 priority_Bps = slave->priority_Bps;321 if ((slave->dev->flags & IFF_UP) == IFF_UP) {322 slave_load = (~0UL - (~0UL / 2)) -323 (priority_Bps) + bytes_queued * 8;324 325 if (slave_load < best_load) {326 best_load = slave_load;327 best_slave = slave;328 }329 } else {330 /* We found a dead slave, kill it. */331 eql_kill_one_slave(queue, slave);332 }333 }334 return best_slave;335}336 337static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)338{339 equalizer_t *eql = netdev_priv(dev);340 slave_t *slave;341 342 spin_lock(&eql->queue.lock);343 344 slave = __eql_schedule_slaves(&eql->queue);345 if (slave) {346 struct net_device *slave_dev = slave->dev;347 348 skb->dev = slave_dev;349 skb->priority = TC_PRIO_FILLER;350 slave->bytes_queued += skb->len;351 dev_queue_xmit(skb);352 dev->stats.tx_packets++;353 } else {354 dev->stats.tx_dropped++;355 dev_kfree_skb(skb);356 }357 358 spin_unlock(&eql->queue.lock);359 360 return NETDEV_TX_OK;361}362 363/*364 * Private ioctl functions365 */366 367/* queue->lock must be held */368static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)369{370 struct list_head *this, *head;371 372 head = &queue->all_slaves;373 list_for_each(this, head) {374 slave_t *slave = list_entry(this, slave_t, list);375 376 if (slave->dev == dev)377 return slave;378 }379 380 return NULL;381}382 383static inline int eql_is_full(slave_queue_t *queue)384{385 equalizer_t *eql = netdev_priv(queue->master_dev);386 387 if (queue->num_slaves >= eql->max_slaves)388 return 1;389 return 0;390}391 392/* queue->lock must be held */393static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)394{395 if (!eql_is_full(queue)) {396 slave_t *duplicate_slave = NULL;397 398 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);399 if (duplicate_slave)400 eql_kill_one_slave(queue, duplicate_slave);401 402 netdev_hold(slave->dev, &slave->dev_tracker, GFP_ATOMIC);403 list_add(&slave->list, &queue->all_slaves);404 queue->num_slaves++;405 slave->dev->flags |= IFF_SLAVE;406 407 return 0;408 }409 410 return -ENOSPC;411}412 413static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)414{415 struct net_device *slave_dev;416 slaving_request_t srq;417 418 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))419 return -EFAULT;420 421 slave_dev = __dev_get_by_name(&init_net, srq.slave_name);422 if (!slave_dev)423 return -ENODEV;424 425 if ((master_dev->flags & IFF_UP) == IFF_UP) {426 /* slave is not a master & not already a slave: */427 if (!eql_is_master(slave_dev) && !eql_is_slave(slave_dev)) {428 slave_t *s = kzalloc(sizeof(*s), GFP_KERNEL);429 equalizer_t *eql = netdev_priv(master_dev);430 int ret;431 432 if (!s)433 return -ENOMEM;434 435 s->dev = slave_dev;436 s->priority = srq.priority;437 s->priority_bps = srq.priority;438 s->priority_Bps = srq.priority / 8;439 440 spin_lock_bh(&eql->queue.lock);441 ret = __eql_insert_slave(&eql->queue, s);442 if (ret)443 kfree(s);444 445 spin_unlock_bh(&eql->queue.lock);446 447 return ret;448 }449 }450 451 return -EINVAL;452}453 454static 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(&init_net, srq.slave_name);465 if (!slave_dev)466 return -ENODEV;467 468 ret = -EINVAL;469 spin_lock_bh(&eql->queue.lock);470 if (eql_is_slave(slave_dev)) {471 slave_t *slave = __eql_find_slave_dev(&eql->queue, slave_dev);472 if (slave) {473 eql_kill_one_slave(&eql->queue, slave);474 ret = 0;475 }476 }477 spin_unlock_bh(&eql->queue.lock);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 if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))510 ret = -EFAULT;511 512 return ret;513}514 515static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)516{517 slave_t *slave;518 equalizer_t *eql;519 struct net_device *slave_dev;520 slave_config_t sc;521 int ret;522 523 if (copy_from_user(&sc, scp, sizeof (slave_config_t)))524 return -EFAULT;525 526 slave_dev = __dev_get_by_name(&init_net, sc.slave_name);527 if (!slave_dev)528 return -ENODEV;529 530 ret = -EINVAL;531 532 eql = netdev_priv(dev);533 spin_lock_bh(&eql->queue.lock);534 if (eql_is_slave(slave_dev)) {535 slave = __eql_find_slave_dev(&eql->queue, slave_dev);536 if (slave) {537 slave->priority = sc.priority;538 slave->priority_bps = sc.priority;539 slave->priority_Bps = sc.priority / 8;540 ret = 0;541 }542 }543 spin_unlock_bh(&eql->queue.lock);544 545 return ret;546}547 548static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)549{550 equalizer_t *eql;551 master_config_t mc;552 553 memset(&mc, 0, sizeof(master_config_t));554 555 if (eql_is_master(dev)) {556 eql = netdev_priv(dev);557 mc.max_slaves = eql->max_slaves;558 mc.min_slaves = eql->min_slaves;559 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))560 return -EFAULT;561 return 0;562 }563 return -EINVAL;564}565 566static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)567{568 equalizer_t *eql;569 master_config_t mc;570 571 if (copy_from_user(&mc, mcp, sizeof (master_config_t)))572 return -EFAULT;573 574 if (eql_is_master(dev)) {575 eql = netdev_priv(dev);576 eql->max_slaves = mc.max_slaves;577 eql->min_slaves = mc.min_slaves;578 return 0;579 }580 return -EINVAL;581}582 583static struct net_device *dev_eql;584 585static int __init eql_init_module(void)586{587 int err;588 589 pr_info("%s\n", version);590 591 dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", NET_NAME_UNKNOWN,592 eql_setup);593 if (!dev_eql)594 return -ENOMEM;595 596 err = register_netdev(dev_eql);597 if (err)598 free_netdev(dev_eql);599 return err;600}601 602static void __exit eql_cleanup_module(void)603{604 unregister_netdev(dev_eql);605 free_netdev(dev_eql);606}607 608module_init(eql_init_module);609module_exit(eql_cleanup_module);610MODULE_DESCRIPTION("Equalizer Load-balancer for serial network interfaces");611MODULE_LICENSE("GPL");612