blob: 815436c6170f5d707caf8fd67029fa6469ac8fed [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
120#include <linux/if.h>
121#include <linux/if_arp.h>
122#include <linux/if_eql.h>
123
124#include <asm/uaccess.h>
125
126static int eql_open(struct net_device *dev);
127static int eql_close(struct net_device *dev);
128static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
129static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);
130static struct net_device_stats *eql_get_stats(struct net_device *dev);
131
132#define eql_is_slave(dev) ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
133#define eql_is_master(dev) ((dev->flags & IFF_MASTER) == IFF_MASTER)
134
Loic Le Loarer14a59e12005-07-21 14:16:54 -0700135static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137static void eql_timer(unsigned long param)
138{
139 equalizer_t *eql = (equalizer_t *) param;
140 struct list_head *this, *tmp, *head;
141
142 spin_lock_bh(&eql->queue.lock);
143 head = &eql->queue.all_slaves;
144 list_for_each_safe(this, tmp, head) {
145 slave_t *slave = list_entry(this, slave_t, list);
146
147 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
148 slave->bytes_queued -= slave->priority_Bps;
149 if (slave->bytes_queued < 0)
150 slave->bytes_queued = 0;
151 } else {
Loic Le Loarer14a59e12005-07-21 14:16:54 -0700152 eql_kill_one_slave(&eql->queue, slave);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 }
154
155 }
156 spin_unlock_bh(&eql->queue.lock);
157
158 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
159 add_timer(&eql->timer);
160}
161
162static char version[] __initdata =
163 "Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
164
165static void __init eql_setup(struct net_device *dev)
166{
167 equalizer_t *eql = netdev_priv(dev);
168
169 SET_MODULE_OWNER(dev);
170
171 init_timer(&eql->timer);
172 eql->timer.data = (unsigned long) eql;
173 eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
174 eql->timer.function = eql_timer;
175
176 spin_lock_init(&eql->queue.lock);
177 INIT_LIST_HEAD(&eql->queue.all_slaves);
178 eql->queue.master_dev = dev;
179
180 dev->open = eql_open;
181 dev->stop = eql_close;
182 dev->do_ioctl = eql_ioctl;
183 dev->hard_start_xmit = eql_slave_xmit;
184 dev->get_stats = eql_get_stats;
185
186 /*
187 * Now we undo some of the things that eth_setup does
188 * that we don't like
189 */
190
191 dev->mtu = EQL_DEFAULT_MTU; /* set to 576 in if_eql.h */
192 dev->flags = IFF_MASTER;
193
194 dev->type = ARPHRD_SLIP;
195 dev->tx_queue_len = 5; /* Hands them off fast */
196}
197
198static int eql_open(struct net_device *dev)
199{
200 equalizer_t *eql = netdev_priv(dev);
201
202 /* XXX We should force this off automatically for the user. */
203 printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
204 "your slave devices.\n", dev->name);
205
Eric Sesterhenn5d9428d2006-04-02 13:52:48 +0200206 BUG_ON(!list_empty(&eql->queue.all_slaves));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
208 eql->min_slaves = 1;
209 eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
210
211 add_timer(&eql->timer);
212
213 return 0;
214}
215
Loic Le Loarer14a59e12005-07-21 14:16:54 -0700216static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217{
218 list_del(&slave->list);
Loic Le Loarer14a59e12005-07-21 14:16:54 -0700219 queue->num_slaves--;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 slave->dev->flags &= ~IFF_SLAVE;
221 dev_put(slave->dev);
222 kfree(slave);
223}
224
225static void eql_kill_slave_queue(slave_queue_t *queue)
226{
227 struct list_head *head, *tmp, *this;
228
229 spin_lock_bh(&queue->lock);
230
231 head = &queue->all_slaves;
232 list_for_each_safe(this, tmp, head) {
233 slave_t *s = list_entry(this, slave_t, list);
234
Loic Le Loarer14a59e12005-07-21 14:16:54 -0700235 eql_kill_one_slave(queue, s);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 }
237
238 spin_unlock_bh(&queue->lock);
239}
240
241static int eql_close(struct net_device *dev)
242{
243 equalizer_t *eql = netdev_priv(dev);
244
245 /*
246 * The timer has to be stopped first before we start hacking away
247 * at the data structure it scans every so often...
248 */
249
250 del_timer_sync(&eql->timer);
251
252 eql_kill_slave_queue(&eql->queue);
253
254 return 0;
255}
256
257static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq);
258static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
259
260static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
261static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
262
263static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
264static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
265
266static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
267{
268 if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
269 !capable(CAP_NET_ADMIN))
270 return -EPERM;
271
272 switch (cmd) {
273 case EQL_ENSLAVE:
274 return eql_enslave(dev, ifr->ifr_data);
275 case EQL_EMANCIPATE:
276 return eql_emancipate(dev, ifr->ifr_data);
277 case EQL_GETSLAVECFG:
278 return eql_g_slave_cfg(dev, ifr->ifr_data);
279 case EQL_SETSLAVECFG:
280 return eql_s_slave_cfg(dev, ifr->ifr_data);
281 case EQL_GETMASTRCFG:
282 return eql_g_master_cfg(dev, ifr->ifr_data);
283 case EQL_SETMASTRCFG:
284 return eql_s_master_cfg(dev, ifr->ifr_data);
285 default:
286 return -EOPNOTSUPP;
287 };
288}
289
290/* queue->lock must be held */
291static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
292{
293 unsigned long best_load = ~0UL;
294 struct list_head *this, *tmp, *head;
295 slave_t *best_slave;
296
297 best_slave = NULL;
298
299 /* Make a pass to set the best slave. */
300 head = &queue->all_slaves;
301 list_for_each_safe(this, tmp, head) {
302 slave_t *slave = list_entry(this, slave_t, list);
303 unsigned long slave_load, bytes_queued, priority_Bps;
304
305 /* Go through the slave list once, updating best_slave
306 * whenever a new best_load is found.
307 */
308 bytes_queued = slave->bytes_queued;
309 priority_Bps = slave->priority_Bps;
310 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
311 slave_load = (~0UL - (~0UL / 2)) -
312 (priority_Bps) + bytes_queued * 8;
313
314 if (slave_load < best_load) {
315 best_load = slave_load;
316 best_slave = slave;
317 }
318 } else {
319 /* We found a dead slave, kill it. */
Loic Le Loarer14a59e12005-07-21 14:16:54 -0700320 eql_kill_one_slave(queue, slave);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321 }
322 }
323 return best_slave;
324}
325
326static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
327{
328 equalizer_t *eql = netdev_priv(dev);
329 slave_t *slave;
330
331 spin_lock(&eql->queue.lock);
332
333 slave = __eql_schedule_slaves(&eql->queue);
334 if (slave) {
335 struct net_device *slave_dev = slave->dev;
336
337 skb->dev = slave_dev;
338 skb->priority = 1;
339 slave->bytes_queued += skb->len;
340 dev_queue_xmit(skb);
341 eql->stats.tx_packets++;
342 } else {
343 eql->stats.tx_dropped++;
344 dev_kfree_skb(skb);
345 }
346
347 spin_unlock(&eql->queue.lock);
348
349 return 0;
350}
351
352static struct net_device_stats * eql_get_stats(struct net_device *dev)
353{
354 equalizer_t *eql = netdev_priv(dev);
355 return &eql->stats;
356}
357
358/*
359 * Private ioctl functions
360 */
361
362/* queue->lock must be held */
363static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
364{
365 struct list_head *this, *head;
366
367 head = &queue->all_slaves;
368 list_for_each(this, head) {
369 slave_t *slave = list_entry(this, slave_t, list);
370
371 if (slave->dev == dev)
372 return slave;
373 }
374
375 return NULL;
376}
377
378static inline int eql_is_full(slave_queue_t *queue)
379{
380 equalizer_t *eql = netdev_priv(queue->master_dev);
381
382 if (queue->num_slaves >= eql->max_slaves)
383 return 1;
384 return 0;
385}
386
387/* queue->lock must be held */
388static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
389{
390 if (!eql_is_full(queue)) {
391 slave_t *duplicate_slave = NULL;
392
393 duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
394 if (duplicate_slave != 0)
Loic Le Loarer14a59e12005-07-21 14:16:54 -0700395 eql_kill_one_slave(queue, duplicate_slave);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396
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
407static 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(srq.slave_name);
416 if (slave_dev) {
417 if ((master_dev->flags & IFF_UP) == IFF_UP) {
418 /* slave is not a master & not already a slave: */
419 if (!eql_is_master(slave_dev) &&
420 !eql_is_slave(slave_dev)) {
421 slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
422 equalizer_t *eql = netdev_priv(master_dev);
423 int ret;
424
425 if (!s) {
426 dev_put(slave_dev);
427 return -ENOMEM;
428 }
429
430 memset(s, 0, sizeof(*s));
431 s->dev = slave_dev;
432 s->priority = srq.priority;
433 s->priority_bps = srq.priority;
434 s->priority_Bps = srq.priority / 8;
435
436 spin_lock_bh(&eql->queue.lock);
437 ret = __eql_insert_slave(&eql->queue, s);
438 if (ret) {
439 dev_put(slave_dev);
440 kfree(s);
441 }
442 spin_unlock_bh(&eql->queue.lock);
443
444 return ret;
445 }
446 }
447 dev_put(slave_dev);
448 }
449
450 return -EINVAL;
451}
452
453static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
454{
455 equalizer_t *eql = netdev_priv(master_dev);
456 struct net_device *slave_dev;
457 slaving_request_t srq;
458 int ret;
459
460 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
461 return -EFAULT;
462
463 slave_dev = dev_get_by_name(srq.slave_name);
464 ret = -EINVAL;
465 if (slave_dev) {
466 spin_lock_bh(&eql->queue.lock);
467
468 if (eql_is_slave(slave_dev)) {
469 slave_t *slave = __eql_find_slave_dev(&eql->queue,
470 slave_dev);
471
472 if (slave) {
Loic Le Loarer14a59e12005-07-21 14:16:54 -0700473 eql_kill_one_slave(&eql->queue, slave);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 ret = 0;
475 }
476 }
477 dev_put(slave_dev);
478
479 spin_unlock_bh(&eql->queue.lock);
480 }
481
482 return ret;
483}
484
485static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
486{
487 equalizer_t *eql = netdev_priv(dev);
488 slave_t *slave;
489 struct net_device *slave_dev;
490 slave_config_t sc;
491 int ret;
492
493 if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
494 return -EFAULT;
495
496 slave_dev = dev_get_by_name(sc.slave_name);
497 if (!slave_dev)
498 return -ENODEV;
499
500 ret = -EINVAL;
501
502 spin_lock_bh(&eql->queue.lock);
503 if (eql_is_slave(slave_dev)) {
504 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
505 if (slave) {
506 sc.priority = slave->priority;
507 ret = 0;
508 }
509 }
510 spin_unlock_bh(&eql->queue.lock);
511
512 dev_put(slave_dev);
513
514 if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
515 ret = -EFAULT;
516
517 return ret;
518}
519
520static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
521{
522 slave_t *slave;
523 equalizer_t *eql;
524 struct net_device *slave_dev;
525 slave_config_t sc;
526 int ret;
527
528 if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
529 return -EFAULT;
530
531 slave_dev = dev_get_by_name(sc.slave_name);
532 if (!slave_dev)
533 return -ENODEV;
534
535 ret = -EINVAL;
536
537 eql = netdev_priv(dev);
538 spin_lock_bh(&eql->queue.lock);
539 if (eql_is_slave(slave_dev)) {
540 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
541 if (slave) {
542 slave->priority = sc.priority;
543 slave->priority_bps = sc.priority;
544 slave->priority_Bps = sc.priority / 8;
545 ret = 0;
546 }
547 }
548 spin_unlock_bh(&eql->queue.lock);
549
550 return ret;
551}
552
553static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
554{
555 equalizer_t *eql;
556 master_config_t mc;
557
558 if (eql_is_master(dev)) {
559 eql = netdev_priv(dev);
560 mc.max_slaves = eql->max_slaves;
561 mc.min_slaves = eql->min_slaves;
562 if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
563 return -EFAULT;
564 return 0;
565 }
566 return -EINVAL;
567}
568
569static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
570{
571 equalizer_t *eql;
572 master_config_t mc;
573
574 if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
575 return -EFAULT;
576
577 if (eql_is_master(dev)) {
578 eql = netdev_priv(dev);
579 eql->max_slaves = mc.max_slaves;
580 eql->min_slaves = mc.min_slaves;
581 return 0;
582 }
583 return -EINVAL;
584}
585
586static struct net_device *dev_eql;
587
588static int __init eql_init_module(void)
589{
590 int err;
591
592 printk(version);
593
594 dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
595 if (!dev_eql)
596 return -ENOMEM;
597
598 err = register_netdev(dev_eql);
599 if (err)
600 free_netdev(dev_eql);
601 return err;
602}
603
604static void __exit eql_cleanup_module(void)
605{
606 unregister_netdev(dev_eql);
607 free_netdev(dev_eql);
608}
609
610module_init(eql_init_module);
611module_exit(eql_cleanup_module);
612MODULE_LICENSE("GPL");