aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/eql.c
blob: a59cf961a436be4fc151b62160f2ad3d17429491 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
/*
 * Equalizer Load-balancer for serial network interfaces.
 *
 * (c) Copyright 1995 Simon "Guru Aleph-Null" Janes
 * NCM: Network and Communications Management, Inc.
 *
 * (c) Copyright 2002 David S. Miller (davem@redhat.com)
 *
 *	This software may be used and distributed according to the terms
 *	of the GNU General Public License, incorporated herein by reference.
 *
 * The author may be reached as simon@ncm.com, or C/O
 *    NCM
 *    Attn: Simon Janes
 *    6803 Whittier Ave
 *    McLean VA 22101
 *    Phone: 1-703-847-0040 ext 103
 */

/*
 * Sources:
 *   skeleton.c by Donald Becker.
 * Inspirations:
 *   The Harried and Overworked Alan Cox
 * Conspiracies:
 *   The Alan Cox and Mike McLagan plot to get someone else to do the code,
 *   which turned out to be me.
 */

/*
 * $Log: eql.c,v $
 * Revision 1.2  1996/04/11 17:51:52  guru
 * Added one-line eql_remove_slave patch.
 *
 * Revision 1.1  1996/04/11 17:44:17  guru
 * Initial revision
 *
 * Revision 3.13  1996/01/21  15:17:18  alan
 * tx_queue_len changes.
 * reformatted.
 *
 * Revision 3.12  1995/03/22  21:07:51  anarchy
 * Added capable() checks on configuration.
 * Moved header file.
 *
 * Revision 3.11  1995/01/19  23:14:31  guru
 * 		      slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
 * 			(priority_Bps) + bytes_queued * 8;
 *
 * Revision 3.10  1995/01/19  23:07:53  guru
 * back to
 * 		      slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
 * 			(priority_Bps) + bytes_queued;
 *
 * Revision 3.9  1995/01/19  22:38:20  guru
 * 		      slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
 * 			(priority_Bps) + bytes_queued * 4;
 *
 * Revision 3.8  1995/01/19  22:30:55  guru
 *       slave_load = (ULONG_MAX - (ULONG_MAX / 2)) -
 * 			(priority_Bps) + bytes_queued * 2;
 *
 * Revision 3.7  1995/01/19  21:52:35  guru
 * printk's trimmed out.
 *
 * Revision 3.6  1995/01/19  21:49:56  guru
 * This is working pretty well. I gained 1 K/s in speed.. now it's just
 * robustness and printk's to be diked out.
 *
 * Revision 3.5  1995/01/18  22:29:59  guru
 * still crashes the kernel when the lock_wait thing is woken up.
 *
 * Revision 3.4  1995/01/18  21:59:47  guru
 * Broken set-bit locking snapshot
 *
 * Revision 3.3  1995/01/17  22:09:18  guru
 * infinite sleep in a lock somewhere..
 *
 * Revision 3.2  1995/01/15  16:46:06  guru
 * Log trimmed of non-pertinent 1.x branch messages
 *
 * Revision 3.1  1995/01/15  14:41:45  guru
 * New Scheduler and timer stuff...
 *
 * Revision 1.15  1995/01/15  14:29:02  guru
 * Will make 1.14 (now 1.15) the 3.0 branch, and the 1.12 the 2.0 branch, the one
 * with the dumber scheduler
 *
 * Revision 1.14  1995/01/15  02:37:08  guru
 * shock.. the kept-new-versions could have zonked working
 * stuff.. shudder
 *
 * Revision 1.13  1995/01/15  02:36:31  guru
 * big changes
 *
 * 	scheduler was torn out and replaced with something smarter
 *
 * 	global names not prefixed with eql_ were renamed to protect
 * 	against namespace collisions
 *
 * 	a few more abstract interfaces were added to facilitate any
 * 	potential change of datastructure.  the driver is still using
 * 	a linked list of slaves.  going to a heap would be a bit of
 * 	an overkill.
 *
 * 	this compiles fine with no warnings.
 *
 * 	the locking mechanism and timer stuff must be written however,
 * 	this version will not work otherwise
 *
 * Sorry, I had to rewrite most of this for 2.5.x -DaveM
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/capability.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/netdevice.h>
#include <net/net_namespace.h>

#include <linux/if.h>
#include <linux/if_arp.h>
#include <linux/if_eql.h>

#include <asm/uaccess.h>

static int eql_open(struct net_device *dev);
static int eql_close(struct net_device *dev);
static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);

#define eql_is_slave(dev)	((dev->flags & IFF_SLAVE) == IFF_SLAVE)
#define eql_is_master(dev)	((dev->flags & IFF_MASTER) == IFF_MASTER)

static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);

static void eql_timer(unsigned long param)
{
	equalizer_t *eql = (equalizer_t *) param;
	struct list_head *this, *tmp, *head;

	spin_lock_bh(&eql->queue.lock);
	head = &eql->queue.all_slaves;
	list_for_each_safe(this, tmp, head) {
		slave_t *slave = list_entry(this, slave_t, list);

		if ((slave->dev->flags & IFF_UP) == IFF_UP) {
			slave->bytes_queued -= slave->priority_Bps;
			if (slave->bytes_queued < 0)
				slave->bytes_queued = 0;
		} else {
			eql_kill_one_slave(&eql->queue, slave);
		}

	}
	spin_unlock_bh(&eql->queue.lock);

	eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
	add_timer(&eql->timer);
}

static const char version[] __initconst =
	"Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)";

static const struct net_device_ops eql_netdev_ops = {
	.ndo_open	= eql_open,
	.ndo_stop	= eql_close,
	.ndo_do_ioctl	= eql_ioctl,
	.ndo_start_xmit	= eql_slave_xmit,
};

static void __init eql_setup(struct net_device *dev)
{
	equalizer_t *eql = netdev_priv(dev);

	init_timer(&eql->timer);
	eql->timer.data     	= (unsigned long) eql;
	eql->timer.expires  	= jiffies + EQL_DEFAULT_RESCHED_IVAL;
	eql->timer.function 	= eql_timer;

	spin_lock_init(&eql->queue.lock);
	INIT_LIST_HEAD(&eql->queue.all_slaves);
	eql->queue.master_dev	= dev;

	dev->netdev_ops		= &eql_netdev_ops;

	/*
	 *	Now we undo some of the things that eth_setup does
	 * 	that we don't like
	 */

	dev->mtu        	= EQL_DEFAULT_MTU;	/* set to 576 in if_eql.h */
	dev->flags      	= IFF_MASTER;

	dev->type       	= ARPHRD_SLIP;
	dev->tx_queue_len 	= 5;		/* Hands them off fast */
	dev->priv_flags	       &= ~IFF_XMIT_DST_RELEASE;
}

static int eql_open(struct net_device *dev)
{
	equalizer_t *eql = netdev_priv(dev);

	/* XXX We should force this off automatically for the user. */
	netdev_info(dev,
		    "remember to turn off Van-Jacobson compression on your slave devices\n");

	BUG_ON(!list_empty(&eql->queue.all_slaves));

	eql->min_slaves = 1;
	eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */

	add_timer(&eql->timer);

	return 0;
}

static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave)
{
	list_del(&slave->list);
	queue->num_slaves--;
	slave->dev->flags &= ~IFF_SLAVE;
	dev_put(slave->dev);
	kfree(slave);
}

static void eql_kill_slave_queue(slave_queue_t *queue)
{
	struct list_head *head, *tmp, *this;

	spin_lock_bh(&queue->lock);

	head = &queue->all_slaves;
	list_for_each_safe(this, tmp, head) {
		slave_t *s = list_entry(this, slave_t, list);

		eql_kill_one_slave(queue, s);
	}

	spin_unlock_bh(&queue->lock);
}

static int eql_close(struct net_device *dev)
{
	equalizer_t *eql = netdev_priv(dev);

	/*
	 *	The timer has to be stopped first before we start hacking away
	 *	at the data structure it scans every so often...
	 */

	del_timer_sync(&eql->timer);

	eql_kill_slave_queue(&eql->queue);

	return 0;
}

static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);

static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);

static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);

static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
{
	if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
	    !capable(CAP_NET_ADMIN))
	  	return -EPERM;

	switch (cmd) {
		case EQL_ENSLAVE:
			return eql_enslave(dev, ifr->ifr_data);
		case EQL_EMANCIPATE:
			return eql_emancipate(dev, ifr->ifr_data);
		case EQL_GETSLAVECFG:
			return eql_g_slave_cfg(dev, ifr->ifr_data);
		case EQL_SETSLAVECFG:
			return eql_s_slave_cfg(dev, ifr->ifr_data);
		case EQL_GETMASTRCFG:
			return eql_g_master_cfg(dev, ifr->ifr_data);
		case EQL_SETMASTRCFG:
			return eql_s_master_cfg(dev, ifr->ifr_data);
		default:
			return -EOPNOTSUPP;
	}
}

/* queue->lock must be held */
static slave_t *__eql_schedule_slaves(slave_queue_t *queue)
{
	unsigned long best_load = ~0UL;
	struct list_head *this, *tmp, *head;
	slave_t *best_slave;

	best_slave = NULL;

	/* Make a pass to set the best slave. */
	head = &queue->all_slaves;
	list_for_each_safe(this, tmp, head) {
		slave_t *slave = list_entry(this, slave_t, list);
		unsigned long slave_load, bytes_queued, priority_Bps;

		/* Go through the slave list once, updating best_slave
		 * whenever a new best_load is found.
		 */
		bytes_queued = slave->bytes_queued;
		priority_Bps = slave->priority_Bps;
		if ((slave->dev->flags & IFF_UP) == IFF_UP) {
			slave_load = (~0UL - (~0UL / 2)) -
				(priority_Bps) + bytes_queued * 8;

			if (slave_load < best_load) {
				best_load = slave_load;
				best_slave = slave;
			}
		} else {
			/* We found a dead slave, kill it. */
			eql_kill_one_slave(queue, slave);
		}
	}
	return best_slave;
}

static netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
{
	equalizer_t *eql = netdev_priv(dev);
	slave_t *slave;

	spin_lock(&eql->queue.lock);

	slave = __eql_schedule_slaves(&eql->queue);
	if (slave) {
		struct net_device *slave_dev = slave->dev;

		skb->dev = slave_dev;
		skb->priority = 1;
		slave->bytes_queued += skb->len;
		dev_queue_xmit(skb);
		dev->stats.tx_packets++;
	} else {
		dev->stats.tx_dropped++;
		dev_kfree_skb(skb);
	}

	spin_unlock(&eql->queue.lock);

	return NETDEV_TX_OK;
}

/*
 *	Private ioctl functions
 */

/* queue->lock must be held */
static slave_t *__eql_find_slave_dev(slave_queue_t *queue, struct net_device *dev)
{
	struct list_head *this, *head;

	head = &queue->all_slaves;
	list_for_each(this, head) {
		slave_t *slave = list_entry(this, slave_t, list);

		if (slave->dev == dev)
			return slave;
	}

	return NULL;
}

static inline int eql_is_full(slave_queue_t *queue)
{
	equalizer_t *eql = netdev_priv(queue->master_dev);

	if (queue->num_slaves >= eql->max_slaves)
		return 1;
	return 0;
}

/* queue->lock must be held */
static int __eql_insert_slave(slave_queue_t *queue, slave_t *slave)
{
	if (!eql_is_full(queue)) {
		slave_t *duplicate_slave = NULL;

		duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
		if (duplicate_slave)
			eql_kill_one_slave(queue, duplicate_slave);

		list_add(&slave->list, &queue->all_slaves);
		queue->num_slaves++;
		slave->dev->flags |= IFF_SLAVE;

		return 0;
	}

	return -ENOSPC;
}

static int eql_enslave(struct net_device *master_dev, slaving_request_t __user *srqp)
{
	struct net_device *slave_dev;
	slaving_request_t srq;

	if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
		return -EFAULT;

	slave_dev  = dev_get_by_name(&init_net, srq.slave_name);
	if (slave_dev) {
		if ((master_dev->flags & IFF_UP) == IFF_UP) {
			/* slave is not a master & not already a slave: */
			if (!eql_is_master(slave_dev) &&
			    !eql_is_slave(slave_dev)) {
				slave_t *s = kmalloc(sizeof(*s), GFP_KERNEL);
				equalizer_t *eql = netdev_priv(master_dev);
				int ret;

				if (!s) {
					dev_put(slave_dev);
					return -ENOMEM;
				}

				memset(s, 0, sizeof(*s));
				s->dev = slave_dev;
				s->priority = srq.priority;
				s->priority_bps = srq.priority;
				s->priority_Bps = srq.priority / 8;

				spin_lock_bh(&eql->queue.lock);
				ret = __eql_insert_slave(&eql->queue, s);
				if (ret) {
					dev_put(slave_dev);
					kfree(s);
				}
				spin_unlock_bh(&eql->queue.lock);

				return ret;
			}
		}
		dev_put(slave_dev);
	}

	return -EINVAL;
}

static int eql_emancipate(struct net_device *master_dev, slaving_request_t __user *srqp)
{
	equalizer_t *eql = netdev_priv(master_dev);
	struct net_device *slave_dev;
	slaving_request_t srq;
	int ret;

	if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
		return -EFAULT;

	slave_dev = dev_get_by_name(&init_net, srq.slave_name);
	ret = -EINVAL;
	if (slave_dev) {
		spin_lock_bh(&eql->queue.lock);

		if (eql_is_slave(slave_dev)) {
			slave_t *slave = __eql_find_slave_dev(&eql->queue,
							      slave_dev);

			if (slave) {
				eql_kill_one_slave(&eql->queue, slave);
				ret = 0;
			}
		}
		dev_put(slave_dev);

		spin_unlock_bh(&eql->queue.lock);
	}

	return ret;
}

static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
{
	equalizer_t *eql = netdev_priv(dev);
	slave_t *slave;
	struct net_device *slave_dev;
	slave_config_t sc;
	int ret;

	if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
		return -EFAULT;

	slave_dev = dev_get_by_name(&init_net, sc.slave_name);
	if (!slave_dev)
		return -ENODEV;

	ret = -EINVAL;

	spin_lock_bh(&eql->queue.lock);
	if (eql_is_slave(slave_dev)) {
		slave = __eql_find_slave_dev(&eql->queue, slave_dev);
		if (slave) {
			sc.priority = slave->priority;
			ret = 0;
		}
	}
	spin_unlock_bh(&eql->queue.lock);

	dev_put(slave_dev);

	if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
		ret = -EFAULT;

	return ret;
}

static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *scp)
{
	slave_t *slave;
	equalizer_t *eql;
	struct net_device *slave_dev;
	slave_config_t sc;
	int ret;

	if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
		return -EFAULT;

	slave_dev = dev_get_by_name(&init_net, sc.slave_name);
	if (!slave_dev)
		return -ENODEV;

	ret = -EINVAL;

	eql = netdev_priv(dev);
	spin_lock_bh(&eql->queue.lock);
	if (eql_is_slave(slave_dev)) {
		slave = __eql_find_slave_dev(&eql->queue, slave_dev);
		if (slave) {
			slave->priority = sc.priority;
			slave->priority_bps = sc.priority;
			slave->priority_Bps = sc.priority / 8;
			ret = 0;
		}
	}
	spin_unlock_bh(&eql->queue.lock);

	dev_put(slave_dev);

	return ret;
}

static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mcp)
{
	equalizer_t *eql;
	master_config_t mc;

	memset(&mc, 0, sizeof(master_config_t));

	if (eql_is_master(dev)) {
		eql = netdev_priv(dev);
		mc.max_slaves = eql->max_slaves;
		mc.min_slaves = eql->min_slaves;
		if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
			return -EFAULT;
		return 0;
	}
	return -EINVAL;
}

static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mcp)
{
	equalizer_t *eql;
	master_config_t mc;

	if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
		return -EFAULT;

	if (eql_is_master(dev)) {
		eql = netdev_priv(dev);
		eql->max_slaves = mc.max_slaves;
		eql->min_slaves = mc.min_slaves;
		return 0;
	}
	return -EINVAL;
}

static struct net_device *dev_eql;

static int __init eql_init_module(void)
{
	int err;

	pr_info("%s\n", version);

	dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
	if (!dev_eql)
		return -ENOMEM;

	err = register_netdev(dev_eql);
	if (err)
		free_netdev(dev_eql);
	return err;
}

static void __exit eql_cleanup_module(void)
{
	unregister_netdev(dev_eql);
	free_netdev(dev_eql);
}

module_init(eql_init_module);
module_exit(eql_cleanup_module);
MODULE_LICENSE("GPL");