[deliverable/linux.git] / drivers / net / eql.c

/*
 * 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
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.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 int 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 char version[] __initdata =
	"Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";

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->open		= eql_open;
	dev->stop		= eql_close;
	dev->do_ioctl		= eql_ioctl;
	dev->hard_start_xmit	= eql_slave_xmit;

	/*
	 *	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 */
}

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

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

	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 int 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 0;
}

/*
 *	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);

	return ret;
}

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

	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;

	printk(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");
Commit	Line	Data
1da177e4 LT	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.
6aa20a22	11	*
1da177e4 LT	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:
6aa20a22	26	* The Alan Cox and Mike McLagan plot to get someone else to do the code,
1da177e4 LT	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>
881d966b	119	#include <net/net_namespace.h>
1da177e4 LT	120
	121	#include <linux/if.h>
	122	#include <linux/if_arp.h>
	123	#include <linux/if_eql.h>
	124
	125	#include <asm/uaccess.h>
	126
	127	static int eql_open(struct net_device *dev);
	128	static int eql_close(struct net_device *dev);
	129	static int eql_ioctl(struct net_device dev, struct ifreq ifr, int cmd);
	130	static int eql_slave_xmit(struct sk_buff skb, struct net_device dev);
1da177e4 LT	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
14a59e18	135	static void eql_kill_one_slave(slave_queue_t queue, slave_t slave);
1da177e4 LT	136
	137	static void eql_timer(unsigned long param)
	138	{
	139	equalizer_t eql = (equalizer_t ) param;
	140	struct list_head this, tmp, *head;
6aa20a22	141
1da177e4 LT	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 {
14a59e18	152	eql_kill_one_slave(&eql->queue, slave);
1da177e4 LT	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
6aa20a22	162	static char version[] __initdata =
1da177e4 LT	163	"Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)\n";
	164
	165	static void __init eql_setup(struct net_device *dev)
	166	{
	167	equalizer_t *eql = netdev_priv(dev);
	168
1da177e4 LT	169	init_timer(&eql->timer);
	170	eql->timer.data = (unsigned long) eql;
	171	eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
	172	eql->timer.function = eql_timer;
	173
	174	spin_lock_init(&eql->queue.lock);
	175	INIT_LIST_HEAD(&eql->queue.all_slaves);
	176	eql->queue.master_dev = dev;
	177
	178	dev->open = eql_open;
	179	dev->stop = eql_close;
	180	dev->do_ioctl = eql_ioctl;
	181	dev->hard_start_xmit = eql_slave_xmit;
6aa20a22	182
1da177e4 LT	183	/*
1da177e4 LT	184	* Now we undo some of the things that eth_setup does
6aa20a22	185	* that we don't like
1da177e4	186	*/
6aa20a22	187
1da177e4 LT	188	dev->mtu = EQL_DEFAULT_MTU; /* set to 576 in if_eql.h */
	189	dev->flags = IFF_MASTER;
	190
	191	dev->type = ARPHRD_SLIP;
	192	dev->tx_queue_len = 5; /* Hands them off fast */
	193	}
	194
	195	static int eql_open(struct net_device *dev)
	196	{
	197	equalizer_t *eql = netdev_priv(dev);
	198
	199	/* XXX We should force this off automatically for the user. */
	200	printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
	201	"your slave devices.\n", dev->name);
	202
5d9428de	203	BUG_ON(!list_empty(&eql->queue.all_slaves));
1da177e4 LT	204
	205	eql->min_slaves = 1;
	206	eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
	207
	208	add_timer(&eql->timer);
	209
	210	return 0;
	211	}
	212
14a59e18	213	static void eql_kill_one_slave(slave_queue_t queue, slave_t slave)
1da177e4 LT	214	{
1da177e4 LT	215	list_del(&slave->list);
14a59e18	216	queue->num_slaves--;
1da177e4 LT	217	slave->dev->flags &= ~IFF_SLAVE;
	218	dev_put(slave->dev);
	219	kfree(slave);
	220	}
	221
	222	static void eql_kill_slave_queue(slave_queue_t *queue)
6aa20a22	223	{
1da177e4 LT	224	struct list_head head, tmp, *this;
	225
	226	spin_lock_bh(&queue->lock);
	227
	228	head = &queue->all_slaves;
	229	list_for_each_safe(this, tmp, head) {
	230	slave_t *s = list_entry(this, slave_t, list);
	231
14a59e18	232	eql_kill_one_slave(queue, s);
1da177e4 LT	233	}
	234
	235	spin_unlock_bh(&queue->lock);
	236	}
	237
	238	static int eql_close(struct net_device *dev)
	239	{
	240	equalizer_t *eql = netdev_priv(dev);
	241
	242	/*
	243	* The timer has to be stopped first before we start hacking away
6aa20a22	244	* at the data structure it scans every so often...
1da177e4 LT	245	*/
	246
	247	del_timer_sync(&eql->timer);
	248
	249	eql_kill_slave_queue(&eql->queue);
	250
	251	return 0;
	252	}
	253
	254	static int eql_enslave(struct net_device dev, slaving_request_t __user srq);
	255	static int eql_emancipate(struct net_device dev, slaving_request_t __user srq);
	256
	257	static int eql_g_slave_cfg(struct net_device dev, slave_config_t __user sc);
	258	static int eql_s_slave_cfg(struct net_device dev, slave_config_t __user sc);
	259
	260	static int eql_g_master_cfg(struct net_device dev, master_config_t __user mc);
	261	static int eql_s_master_cfg(struct net_device dev, master_config_t __user mc);
	262
	263	static int eql_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
6aa20a22	264	{
1da177e4 LT	265	if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
	266	!capable(CAP_NET_ADMIN))
	267	return -EPERM;
	268
	269	switch (cmd) {
	270	case EQL_ENSLAVE:
	271	return eql_enslave(dev, ifr->ifr_data);
	272	case EQL_EMANCIPATE:
	273	return eql_emancipate(dev, ifr->ifr_data);
	274	case EQL_GETSLAVECFG:
	275	return eql_g_slave_cfg(dev, ifr->ifr_data);
	276	case EQL_SETSLAVECFG:
	277	return eql_s_slave_cfg(dev, ifr->ifr_data);
	278	case EQL_GETMASTRCFG:
	279	return eql_g_master_cfg(dev, ifr->ifr_data);
	280	case EQL_SETMASTRCFG:
	281	return eql_s_master_cfg(dev, ifr->ifr_data);
	282	default:
	283	return -EOPNOTSUPP;
	284	};
	285	}
	286
	287	/* queue->lock must be held */
	288	static slave_t __eql_schedule_slaves(slave_queue_t queue)
	289	{
	290	unsigned long best_load = ~0UL;
	291	struct list_head this, tmp, *head;
	292	slave_t *best_slave;
	293
	294	best_slave = NULL;
	295
	296	/* Make a pass to set the best slave. */
	297	head = &queue->all_slaves;
	298	list_for_each_safe(this, tmp, head) {
	299	slave_t *slave = list_entry(this, slave_t, list);
6aa20a22	300	unsigned long slave_load, bytes_queued, priority_Bps;
1da177e4 LT	301
	302	/* Go through the slave list once, updating best_slave
	303	* whenever a new best_load is found.
	304	*/
	305	bytes_queued = slave->bytes_queued;
6aa20a22	306	priority_Bps = slave->priority_Bps;
1da177e4	307	if ((slave->dev->flags & IFF_UP) == IFF_UP) {
6aa20a22	308	slave_load = (~0UL - (~0UL / 2)) -
1da177e4 LT	309	(priority_Bps) + bytes_queued * 8;
	310
	311	if (slave_load < best_load) {
	312	best_load = slave_load;
	313	best_slave = slave;
	314	}
	315	} else {
	316	/* We found a dead slave, kill it. */
14a59e18	317	eql_kill_one_slave(queue, slave);
1da177e4 LT	318	}
	319	}
	320	return best_slave;
	321	}
	322
	323	static int eql_slave_xmit(struct sk_buff skb, struct net_device dev)
	324	{
	325	equalizer_t *eql = netdev_priv(dev);
	326	slave_t *slave;
	327
	328	spin_lock(&eql->queue.lock);
	329
	330	slave = __eql_schedule_slaves(&eql->queue);
	331	if (slave) {
	332	struct net_device *slave_dev = slave->dev;
	333
	334	skb->dev = slave_dev;
	335	skb->priority = 1;
6aa20a22	336	slave->bytes_queued += skb->len;
1da177e4	337	dev_queue_xmit(skb);
09f75cd7	338	dev->stats.tx_packets++;
1da177e4	339	} else {
09f75cd7	340	dev->stats.tx_dropped++;
1da177e4	341	dev_kfree_skb(skb);
6aa20a22	342	}
1da177e4 LT	343
	344	spin_unlock(&eql->queue.lock);
	345
	346	return 0;
	347	}
	348
1da177e4 LT	349	/*
	350	* Private ioctl functions
	351	*/
	352
	353	/* queue->lock must be held */
	354	static slave_t __eql_find_slave_dev(slave_queue_t queue, struct net_device *dev)
	355	{
	356	struct list_head this, head;
	357
	358	head = &queue->all_slaves;
	359	list_for_each(this, head) {
	360	slave_t *slave = list_entry(this, slave_t, list);
	361
	362	if (slave->dev == dev)
	363	return slave;
	364	}
	365
	366	return NULL;
	367	}
	368
	369	static inline int eql_is_full(slave_queue_t *queue)
	370	{
	371	equalizer_t *eql = netdev_priv(queue->master_dev);
	372
	373	if (queue->num_slaves >= eql->max_slaves)
	374	return 1;
	375	return 0;
	376	}
	377
	378	/* queue->lock must be held */
	379	static int __eql_insert_slave(slave_queue_t queue, slave_t slave)
	380	{
	381	if (!eql_is_full(queue)) {
	382	slave_t *duplicate_slave = NULL;
	383
	384	duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
37d2e731	385	if (duplicate_slave)
14a59e18	386	eql_kill_one_slave(queue, duplicate_slave);
1da177e4 LT	387
	388	list_add(&slave->list, &queue->all_slaves);
	389	queue->num_slaves++;
	390	slave->dev->flags \|= IFF_SLAVE;
	391
	392	return 0;
	393	}
	394
	395	return -ENOSPC;
	396	}
	397
	398	static int eql_enslave(struct net_device master_dev, slaving_request_t __user srqp)
	399	{
	400	struct net_device *slave_dev;
	401	slaving_request_t srq;
	402
	403	if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
	404	return -EFAULT;
	405
881d966b	406	slave_dev = dev_get_by_name(&init_net, srq.slave_name);
1da177e4 LT	407	if (slave_dev) {
	408	if ((master_dev->flags & IFF_UP) == IFF_UP) {
	409	/* slave is not a master & not already a slave: */
	410	if (!eql_is_master(slave_dev) &&
	411	!eql_is_slave(slave_dev)) {
	412	slave_t s = kmalloc(sizeof(s), GFP_KERNEL);
	413	equalizer_t *eql = netdev_priv(master_dev);
	414	int ret;
	415
	416	if (!s) {
	417	dev_put(slave_dev);
	418	return -ENOMEM;
	419	}
	420
	421	memset(s, 0, sizeof(*s));
	422	s->dev = slave_dev;
	423	s->priority = srq.priority;
	424	s->priority_bps = srq.priority;
	425	s->priority_Bps = srq.priority / 8;
	426
	427	spin_lock_bh(&eql->queue.lock);
	428	ret = __eql_insert_slave(&eql->queue, s);
	429	if (ret) {
	430	dev_put(slave_dev);
	431	kfree(s);
	432	}
	433	spin_unlock_bh(&eql->queue.lock);
	434
	435	return ret;
	436	}
	437	}
	438	dev_put(slave_dev);
	439	}
	440
	441	return -EINVAL;
	442	}
	443
	444	static int eql_emancipate(struct net_device master_dev, slaving_request_t __user srqp)
	445	{
	446	equalizer_t *eql = netdev_priv(master_dev);
	447	struct net_device *slave_dev;
	448	slaving_request_t srq;
	449	int ret;
	450
	451	if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
	452	return -EFAULT;
	453
881d966b	454	slave_dev = dev_get_by_name(&init_net, srq.slave_name);
1da177e4 LT	455	ret = -EINVAL;
	456	if (slave_dev) {
	457	spin_lock_bh(&eql->queue.lock);
	458
	459	if (eql_is_slave(slave_dev)) {
	460	slave_t *slave = __eql_find_slave_dev(&eql->queue,
	461	slave_dev);
	462
	463	if (slave) {
14a59e18	464	eql_kill_one_slave(&eql->queue, slave);
1da177e4 LT	465	ret = 0;
	466	}
	467	}
	468	dev_put(slave_dev);
	469
	470	spin_unlock_bh(&eql->queue.lock);
	471	}
	472
	473	return ret;
	474	}
	475
	476	static int eql_g_slave_cfg(struct net_device dev, slave_config_t __user scp)
	477	{
	478	equalizer_t *eql = netdev_priv(dev);
	479	slave_t *slave;
	480	struct net_device *slave_dev;
	481	slave_config_t sc;
	482	int ret;
	483
	484	if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
	485	return -EFAULT;
	486
881d966b	487	slave_dev = dev_get_by_name(&init_net, sc.slave_name);
1da177e4 LT	488	if (!slave_dev)
	489	return -ENODEV;
	490
	491	ret = -EINVAL;
	492
	493	spin_lock_bh(&eql->queue.lock);
	494	if (eql_is_slave(slave_dev)) {
	495	slave = __eql_find_slave_dev(&eql->queue, slave_dev);
	496	if (slave) {
	497	sc.priority = slave->priority;
	498	ret = 0;
	499	}
	500	}
	501	spin_unlock_bh(&eql->queue.lock);
	502
	503	dev_put(slave_dev);
	504
	505	if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
	506	ret = -EFAULT;
	507
	508	return ret;
	509	}
	510
	511	static int eql_s_slave_cfg(struct net_device dev, slave_config_t __user scp)
	512	{
	513	slave_t *slave;
	514	equalizer_t *eql;
	515	struct net_device *slave_dev;
	516	slave_config_t sc;
	517	int ret;
	518
	519	if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
	520	return -EFAULT;
	521
881d966b	522	slave_dev = dev_get_by_name(&init_net, sc.slave_name);
1da177e4 LT	523	if (!slave_dev)
	524	return -ENODEV;
	525
	526	ret = -EINVAL;
	527
	528	eql = netdev_priv(dev);
	529	spin_lock_bh(&eql->queue.lock);
	530	if (eql_is_slave(slave_dev)) {
	531	slave = __eql_find_slave_dev(&eql->queue, slave_dev);
	532	if (slave) {
	533	slave->priority = sc.priority;
	534	slave->priority_bps = sc.priority;
	535	slave->priority_Bps = sc.priority / 8;
	536	ret = 0;
	537	}
	538	}
	539	spin_unlock_bh(&eql->queue.lock);
	540
	541	return ret;
	542	}
	543
	544	static int eql_g_master_cfg(struct net_device dev, master_config_t __user mcp)
	545	{
	546	equalizer_t *eql;
	547	master_config_t mc;
	548
	549	if (eql_is_master(dev)) {
	550	eql = netdev_priv(dev);
	551	mc.max_slaves = eql->max_slaves;
	552	mc.min_slaves = eql->min_slaves;
	553	if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
	554	return -EFAULT;
	555	return 0;
	556	}
	557	return -EINVAL;
	558	}
	559
	560	static int eql_s_master_cfg(struct net_device dev, master_config_t __user mcp)
	561	{
	562	equalizer_t *eql;
	563	master_config_t mc;
	564
	565	if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
	566	return -EFAULT;
	567
	568	if (eql_is_master(dev)) {
	569	eql = netdev_priv(dev);
	570	eql->max_slaves = mc.max_slaves;
	571	eql->min_slaves = mc.min_slaves;
	572	return 0;
	573	}
	574	return -EINVAL;
	575	}
	576
	577	static struct net_device *dev_eql;
	578
	579	static int __init eql_init_module(void)
	580	{
	581	int err;
	582
	583	printk(version);
	584
	585	dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
	586	if (!dev_eql)
587	return -ENOMEM;
588
589	err = register_netdev(dev_eql);
6aa20a22	590	if (err)
1da177e4 LT	591	free_netdev(dev_eql);
	592	return err;
	593	}
	594
	595	static void __exit eql_cleanup_module(void)
	596	{
	597	unregister_netdev(dev_eql);
	598	free_netdev(dev_eql);
	599	}
	600
	601	module_init(eql_init_module);
	602	module_exit(eql_cleanup_module);
	603	MODULE_LICENSE("GPL");