blob: dd686582037255154654da59790134e532d81a91 [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
135static void eql_kill_one_slave(slave_t *slave);
136
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 {
152 eql_kill_one_slave(slave);
153 }
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
206 if (!list_empty(&eql->queue.all_slaves))
207 BUG();
208
209 eql->min_slaves = 1;
210 eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
211
212 add_timer(&eql->timer);
213
214 return 0;
215}
216
217static void eql_kill_one_slave(slave_t *slave)
218{
219 list_del(&slave->list);
220 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
235 eql_kill_one_slave(s);
236 queue->num_slaves--;
237 }
238
239 spin_unlock_bh(&queue->lock);
240}
241
242static int eql_close(struct net_device *dev)
243{
244 equalizer_t *eql = netdev_priv(dev);
245
246 /*
247 * The timer has to be stopped first before we start hacking away
248 * at the data structure it scans every so often...
249 */
250
251 del_timer_sync(&eql->timer);
252
253 eql_kill_slave_queue(&eql->queue);
254
255 return 0;
256}
257
258static int eql_enslave(struct net_device *dev, slaving_request_t __user *srq);
259static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
260
261static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
262static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
263
264static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
265static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
266
267static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
268{
269 if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
270 !capable(CAP_NET_ADMIN))
271 return -EPERM;
272
273 switch (cmd) {
274 case EQL_ENSLAVE:
275 return eql_enslave(dev, ifr->ifr_data);
276 case EQL_EMANCIPATE:
277 return eql_emancipate(dev, ifr->ifr_data);
278 case EQL_GETSLAVECFG:
279 return eql_g_slave_cfg(dev, ifr->ifr_data);
280 case EQL_SETSLAVECFG:
281 return eql_s_slave_cfg(dev, ifr->ifr_data);
282 case EQL_GETMASTRCFG:
283 return eql_g_master_cfg(dev, ifr->ifr_data);
284 case EQL_SETMASTRCFG:
285 return eql_s_master_cfg(dev, ifr->ifr_data);
286 default:
287 return -EOPNOTSUPP;
288 };
289}
290
291/* queue->lock must be held */
292static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
293{
294 unsigned long best_load = ~0UL;
295 struct list_head *this, *tmp, *head;
296 slave_t *best_slave;
297
298 best_slave = NULL;
299
300 /* Make a pass to set the best slave. */
301 head = &queue->all_slaves;
302 list_for_each_safe(this, tmp, head) {
303 slave_t *slave = list_entry(this, slave_t, list);
304 unsigned long slave_load, bytes_queued, priority_Bps;
305
306 /* Go through the slave list once, updating best_slave
307 * whenever a new best_load is found.
308 */
309 bytes_queued = slave->bytes_queued;
310 priority_Bps = slave->priority_Bps;
311 if ((slave->dev->flags & IFF_UP) == IFF_UP) {
312 slave_load = (~0UL - (~0UL / 2)) -
313 (priority_Bps) + bytes_queued * 8;
314
315 if (slave_load < best_load) {
316 best_load = slave_load;
317 best_slave = slave;
318 }
319 } else {
320 /* We found a dead slave, kill it. */
321 eql_kill_one_slave(slave);
322 }
323 }
324 return best_slave;
325}
326
327static int eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
328{
329 equalizer_t *eql = netdev_priv(dev);
330 slave_t *slave;
331
332 spin_lock(&eql->queue.lock);
333
334 slave = __eql_schedule_slaves(&eql->queue);
335 if (slave) {
336 struct net_device *slave_dev = slave->dev;
337
338 skb->dev = slave_dev;
339 skb->priority = 1;
340 slave->bytes_queued += skb->len;
341 dev_queue_xmit(skb);
342 eql->stats.tx_packets++;
343 } else {
344 eql->stats.tx_dropped++;
345 dev_kfree_skb(skb);
346 }
347
348 spin_unlock(&eql->queue.lock);
349
350 return 0;
351}
352
353static struct net_device_stats * eql_get_stats(struct net_device *dev)
354{
355 equalizer_t *eql = netdev_priv(dev);
356 return &eql->stats;
357}
358
359/*
360 * Private ioctl functions
361 */
362
363/* queue->lock must be held */
364static 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
379static 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 */
389static 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 != 0)
396 eql_kill_one_slave(duplicate_slave);
397
398 list_add(&slave->list, &queue->all_slaves);
399 queue->num_slaves++;
400 slave->dev->flags |= IFF_SLAVE;
401
402 return 0;
403 }
404
405 return -ENOSPC;
406}
407
408static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
409{
410 struct net_device *slave_dev;
411 slaving_request_t srq;
412
413 if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
414 return -EFAULT;
415
416 slave_dev = dev_get_by_name(srq.slave_name);
417 if (slave_dev) {
418 if ((master_dev->flags & IFF_UP) == IFF_UP) {
419 /* slave is not a master & not already a slave: */
420 if (!eql_is_master(slave_dev) &&
421 !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 dev_put(slave_dev);
428 return -ENOMEM;
429 }
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 dev_put(slave_dev);
441 kfree(s);
442 }
443 spin_unlock_bh(&eql->queue.lock);
444
445 return ret;
446 }
447 }
448 dev_put(slave_dev);
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(srq.slave_name);
465 ret = -EINVAL;
466 if (slave_dev) {
467 spin_lock_bh(&eql->queue.lock);
468
469 if (eql_is_slave(slave_dev)) {
470 slave_t *slave = __eql_find_slave_dev(&eql->queue,
471 slave_dev);
472
473 if (slave) {
474 eql_kill_one_slave(slave);
475 ret = 0;
476 }
477 }
478 dev_put(slave_dev);
479
480 spin_unlock_bh(&eql->queue.lock);
481 }
482
483 return ret;
484}
485
486static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
487{
488 equalizer_t *eql = netdev_priv(dev);
489 slave_t *slave;
490 struct net_device *slave_dev;
491 slave_config_t sc;
492 int ret;
493
494 if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
495 return -EFAULT;
496
497 slave_dev = dev_get_by_name(sc.slave_name);
498 if (!slave_dev)
499 return -ENODEV;
500
501 ret = -EINVAL;
502
503 spin_lock_bh(&eql->queue.lock);
504 if (eql_is_slave(slave_dev)) {
505 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
506 if (slave) {
507 sc.priority = slave->priority;
508 ret = 0;
509 }
510 }
511 spin_unlock_bh(&eql->queue.lock);
512
513 dev_put(slave_dev);
514
515 if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
516 ret = -EFAULT;
517
518 return ret;
519}
520
521static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
522{
523 slave_t *slave;
524 equalizer_t *eql;
525 struct net_device *slave_dev;
526 slave_config_t sc;
527 int ret;
528
529 if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
530 return -EFAULT;
531
532 slave_dev = dev_get_by_name(sc.slave_name);
533 if (!slave_dev)
534 return -ENODEV;
535
536 ret = -EINVAL;
537
538 eql = netdev_priv(dev);
539 spin_lock_bh(&eql->queue.lock);
540 if (eql_is_slave(slave_dev)) {
541 slave = __eql_find_slave_dev(&eql->queue, slave_dev);
542 if (slave) {
543 slave->priority = sc.priority;
544 slave->priority_bps = sc.priority;
545 slave->priority_Bps = sc.priority / 8;
546 ret = 0;
547 }
548 }
549 spin_unlock_bh(&eql->queue.lock);
550
551 return ret;
552}
553
554static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
555{
556 equalizer_t *eql;
557 master_config_t mc;
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");