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v6.8
  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/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 does
194	 * 	that we don't like
195	 */
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 away
254	 *	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_slave
317		 * 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 functions
365 */
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");
v4.17
  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
132static int eql_open(struct net_device *dev);
133static int eql_close(struct net_device *dev);
134static int eql_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
 
135static 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
140static void eql_kill_one_slave(slave_queue_t *queue, slave_t *slave);
141
142static 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
167static const char version[] __initconst =
168	"Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)";
169
170static 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
177static 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
203static 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
221static 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
230static 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
246static 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
262static int eql_enslave(struct net_device *dev,  slaving_request_t __user *srq);
263static int eql_emancipate(struct net_device *dev, slaving_request_t __user *srq);
264
265static int eql_g_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
266static int eql_s_slave_cfg(struct net_device *dev, slave_config_t __user *sc);
267
268static int eql_g_master_cfg(struct net_device *dev, master_config_t __user *mc);
269static int eql_s_master_cfg(struct net_device *dev, master_config_t __user *mc);
270
271static 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 */
296static 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
331static 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 */
362static 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
377static 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 */
387static 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
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(&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
449static 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
477static 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
510static 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
543static 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
561static 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
578static struct net_device *dev_eql;
579
580static 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
597static void __exit eql_cleanup_module(void)
598{
599	unregister_netdev(dev_eql);
600	free_netdev(dev_eql);
601}
602
603module_init(eql_init_module);
604module_exit(eql_cleanup_module);
 
605MODULE_LICENSE("GPL");