[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 ([email protected])
 *
 *	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 [email protected], 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 <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);
static struct net_device_stats *eql_get_stats(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 ([email protected]) and David S. Miller ([email protected])\n";

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

	SET_MODULE_OWNER(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;
	dev->get_stats		= eql_get_stats;
  
	/*
	 *	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);
		eql->stats.tx_packets++;
	} else {
		eql->stats.tx_dropped++;
		dev_kfree_skb(skb);
	}	  

	spin_unlock(&eql->queue.lock);

	return 0;
}

static struct net_device_stats * eql_get_stats(struct net_device *dev)
{
	equalizer_t *eql = netdev_priv(dev);
	return &eql->stats;
}

/*
 *	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 != 0)
			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(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(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(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(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 ([email protected])
	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 [email protected], 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
126	static int eql_open(struct net_device *dev);
127	static int eql_close(struct net_device *dev);
128	static int eql_ioctl(struct net_device dev, struct ifreq ifr, int cmd);
129	static int eql_slave_xmit(struct sk_buff skb, struct net_device dev);
130	static 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
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;
	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 {
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
	162	static char version[] __initdata =
	163	"Equalizer2002: Simon Janes ([email protected]) and David S. Miller ([email protected])\n";
	164
	165	static 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
	198	static 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
5d9428de	206	BUG_ON(!list_empty(&eql->queue.all_slaves));
1da177e4 LT	207
	208	eql->min_slaves = 1;
	209	eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
	210
	211	add_timer(&eql->timer);
	212
	213	return 0;
	214	}
	215
14a59e18	216	static void eql_kill_one_slave(slave_queue_t queue, slave_t slave)
1da177e4 LT	217	{
1da177e4 LT	218	list_del(&slave->list);
14a59e18	219	queue->num_slaves--;
1da177e4 LT	220	slave->dev->flags &= ~IFF_SLAVE;
	221	dev_put(slave->dev);
	222	kfree(slave);
	223	}
	224
	225	static 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
14a59e18	235	eql_kill_one_slave(queue, s);
1da177e4 LT	236	}
	237
	238	spin_unlock_bh(&queue->lock);
	239	}
	240
	241	static int eql_close(struct net_device *dev)
	242	{
	243	equalizer_t *eql = netdev_priv(dev);
	244
	245	/*
	246	* The timer has to be stopped first before we start hacking away
	247	* at the data structure it scans every so often...
	248	*/
	249
	250	del_timer_sync(&eql->timer);
	251
	252	eql_kill_slave_queue(&eql->queue);
	253
	254	return 0;
	255	}
	256
	257	static int eql_enslave(struct net_device dev, slaving_request_t __user srq);
	258	static int eql_emancipate(struct net_device dev, slaving_request_t __user srq);
	259
	260	static int eql_g_slave_cfg(struct net_device dev, slave_config_t __user sc);
	261	static int eql_s_slave_cfg(struct net_device dev, slave_config_t __user sc);
	262
	263	static int eql_g_master_cfg(struct net_device dev, master_config_t __user mc);
	264	static int eql_s_master_cfg(struct net_device dev, master_config_t __user mc);
	265
	266	static int eql_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
	267	{
	268	if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
	269	!capable(CAP_NET_ADMIN))
	270	return -EPERM;
	271
	272	switch (cmd) {
	273	case EQL_ENSLAVE:
	274	return eql_enslave(dev, ifr->ifr_data);
	275	case EQL_EMANCIPATE:
	276	return eql_emancipate(dev, ifr->ifr_data);
	277	case EQL_GETSLAVECFG:
	278	return eql_g_slave_cfg(dev, ifr->ifr_data);
	279	case EQL_SETSLAVECFG:
	280	return eql_s_slave_cfg(dev, ifr->ifr_data);
	281	case EQL_GETMASTRCFG:
	282	return eql_g_master_cfg(dev, ifr->ifr_data);
	283	case EQL_SETMASTRCFG:
	284	return eql_s_master_cfg(dev, ifr->ifr_data);
	285	default:
	286	return -EOPNOTSUPP;
	287	};
	288	}
	289
	290	/* queue->lock must be held */
	291	static slave_t __eql_schedule_slaves(slave_queue_t queue)
	292	{
	293	unsigned long best_load = ~0UL;
	294	struct list_head this, tmp, *head;
	295	slave_t *best_slave;
	296
	297	best_slave = NULL;
	298
	299	/* Make a pass to set the best slave. */
300	head = &queue->all_slaves;
301	list_for_each_safe(this, tmp, head) {
302	slave_t *slave = list_entry(this, slave_t, list);
303	unsigned long slave_load, bytes_queued, priority_Bps;
304
305	/* Go through the slave list once, updating best_slave
306	* whenever a new best_load is found.
307	*/
308	bytes_queued = slave->bytes_queued;
309	priority_Bps = slave->priority_Bps;
310	if ((slave->dev->flags & IFF_UP) == IFF_UP) {
311	slave_load = (~0UL - (~0UL / 2)) -
312	(priority_Bps) + bytes_queued * 8;
313
314	if (slave_load < best_load) {
315	best_load = slave_load;
316	best_slave = slave;
317	}
318	} else {
319	/* We found a dead slave, kill it. */
14a59e18	320	eql_kill_one_slave(queue, slave);
1da177e4 LT	321	}
	322	}
	323	return best_slave;
	324	}
	325
	326	static int eql_slave_xmit(struct sk_buff skb, struct net_device dev)
	327	{
	328	equalizer_t *eql = netdev_priv(dev);
	329	slave_t *slave;
	330
	331	spin_lock(&eql->queue.lock);
	332
	333	slave = __eql_schedule_slaves(&eql->queue);
	334	if (slave) {
	335	struct net_device *slave_dev = slave->dev;
	336
	337	skb->dev = slave_dev;
	338	skb->priority = 1;
	339	slave->bytes_queued += skb->len;
	340	dev_queue_xmit(skb);
	341	eql->stats.tx_packets++;
	342	} else {
	343	eql->stats.tx_dropped++;
	344	dev_kfree_skb(skb);
	345	}
	346
	347	spin_unlock(&eql->queue.lock);
	348
	349	return 0;
	350	}
	351
	352	static struct net_device_stats * eql_get_stats(struct net_device *dev)
	353	{
	354	equalizer_t *eql = netdev_priv(dev);
	355	return &eql->stats;
	356	}
	357
	358	/*
	359	* Private ioctl functions
	360	*/
	361
	362	/* queue->lock must be held */
	363	static slave_t __eql_find_slave_dev(slave_queue_t queue, struct net_device *dev)
	364	{
	365	struct list_head this, head;
	366
	367	head = &queue->all_slaves;
	368	list_for_each(this, head) {
	369	slave_t *slave = list_entry(this, slave_t, list);
	370
	371	if (slave->dev == dev)
	372	return slave;
	373	}
	374
	375	return NULL;
	376	}
	377
	378	static inline int eql_is_full(slave_queue_t *queue)
	379	{
	380	equalizer_t *eql = netdev_priv(queue->master_dev);
	381
	382	if (queue->num_slaves >= eql->max_slaves)
	383	return 1;
	384	return 0;
385	}
386
387	/* queue->lock must be held */
388	static int __eql_insert_slave(slave_queue_t queue, slave_t slave)
389	{
390	if (!eql_is_full(queue)) {
391	slave_t *duplicate_slave = NULL;
392
393	duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
394	if (duplicate_slave != 0)
14a59e18	395	eql_kill_one_slave(queue, duplicate_slave);
1da177e4 LT	396
	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
	407	static int eql_enslave(struct net_device master_dev, slaving_request_t __user srqp)
	408	{
	409	struct net_device *slave_dev;
	410	slaving_request_t srq;
	411
	412	if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
	413	return -EFAULT;
	414
	415	slave_dev = dev_get_by_name(srq.slave_name);
	416	if (slave_dev) {
	417	if ((master_dev->flags & IFF_UP) == IFF_UP) {
	418	/* slave is not a master & not already a slave: */
	419	if (!eql_is_master(slave_dev) &&
	420	!eql_is_slave(slave_dev)) {
	421	slave_t s = kmalloc(sizeof(s), GFP_KERNEL);
	422	equalizer_t *eql = netdev_priv(master_dev);
	423	int ret;
	424
	425	if (!s) {
	426	dev_put(slave_dev);
	427	return -ENOMEM;
	428	}
	429
	430	memset(s, 0, sizeof(*s));
	431	s->dev = slave_dev;
	432	s->priority = srq.priority;
	433	s->priority_bps = srq.priority;
	434	s->priority_Bps = srq.priority / 8;
	435
	436	spin_lock_bh(&eql->queue.lock);
	437	ret = __eql_insert_slave(&eql->queue, s);
	438	if (ret) {
	439	dev_put(slave_dev);
	440	kfree(s);
	441	}
	442	spin_unlock_bh(&eql->queue.lock);
	443
	444	return ret;
	445	}
	446	}
	447	dev_put(slave_dev);
	448	}
	449
	450	return -EINVAL;
	451	}
	452
	453	static int eql_emancipate(struct net_device master_dev, slaving_request_t __user srqp)
	454	{
	455	equalizer_t *eql = netdev_priv(master_dev);
	456	struct net_device *slave_dev;
	457	slaving_request_t srq;
	458	int ret;
	459
460	if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
461	return -EFAULT;
462
463	slave_dev = dev_get_by_name(srq.slave_name);
464	ret = -EINVAL;
465	if (slave_dev) {
466	spin_lock_bh(&eql->queue.lock);
467
468	if (eql_is_slave(slave_dev)) {
469	slave_t *slave = __eql_find_slave_dev(&eql->queue,
470	slave_dev);
471
472	if (slave) {
14a59e18	473	eql_kill_one_slave(&eql->queue, slave);
1da177e4 LT	474	ret = 0;
	475	}
	476	}
	477	dev_put(slave_dev);
	478
	479	spin_unlock_bh(&eql->queue.lock);
	480	}
	481
	482	return ret;
	483	}
	484
	485	static int eql_g_slave_cfg(struct net_device dev, slave_config_t __user scp)
	486	{
	487	equalizer_t *eql = netdev_priv(dev);
	488	slave_t *slave;
	489	struct net_device *slave_dev;
	490	slave_config_t sc;
	491	int ret;
	492
	493	if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
	494	return -EFAULT;
	495
	496	slave_dev = dev_get_by_name(sc.slave_name);
	497	if (!slave_dev)
	498	return -ENODEV;
	499
	500	ret = -EINVAL;
	501
	502	spin_lock_bh(&eql->queue.lock);
	503	if (eql_is_slave(slave_dev)) {
	504	slave = __eql_find_slave_dev(&eql->queue, slave_dev);
	505	if (slave) {
	506	sc.priority = slave->priority;
	507	ret = 0;
	508	}
	509	}
	510	spin_unlock_bh(&eql->queue.lock);
	511
	512	dev_put(slave_dev);
	513
	514	if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
	515	ret = -EFAULT;
	516
	517	return ret;
	518	}
	519
	520	static int eql_s_slave_cfg(struct net_device dev, slave_config_t __user scp)
	521	{
	522	slave_t *slave;
	523	equalizer_t *eql;
	524	struct net_device *slave_dev;
	525	slave_config_t sc;
	526	int ret;
	527
	528	if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
	529	return -EFAULT;
	530
	531	slave_dev = dev_get_by_name(sc.slave_name);
	532	if (!slave_dev)
	533	return -ENODEV;
	534
	535	ret = -EINVAL;
	536
	537	eql = netdev_priv(dev);
538	spin_lock_bh(&eql->queue.lock);
539	if (eql_is_slave(slave_dev)) {
540	slave = __eql_find_slave_dev(&eql->queue, slave_dev);
541	if (slave) {
542	slave->priority = sc.priority;
543	slave->priority_bps = sc.priority;
544	slave->priority_Bps = sc.priority / 8;
545	ret = 0;
546	}
547	}
548	spin_unlock_bh(&eql->queue.lock);
549
550	return ret;
551	}
552
553	static int eql_g_master_cfg(struct net_device dev, master_config_t __user mcp)
554	{
555	equalizer_t *eql;
556	master_config_t mc;
557
558	if (eql_is_master(dev)) {
559	eql = netdev_priv(dev);
560	mc.max_slaves = eql->max_slaves;
561	mc.min_slaves = eql->min_slaves;
562	if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
563	return -EFAULT;
564	return 0;
565	}
566	return -EINVAL;
567	}
568
569	static int eql_s_master_cfg(struct net_device dev, master_config_t __user mcp)
570	{
571	equalizer_t *eql;
572	master_config_t mc;
573
574	if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
575	return -EFAULT;
576
577	if (eql_is_master(dev)) {
578	eql = netdev_priv(dev);
579	eql->max_slaves = mc.max_slaves;
580	eql->min_slaves = mc.min_slaves;
581	return 0;
582	}
583	return -EINVAL;
584	}
585
586	static struct net_device *dev_eql;
587
588	static int __init eql_init_module(void)
589	{
590	int err;
591
592	printk(version);
593
594	dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
595	if (!dev_eql)
596	return -ENOMEM;
597
598	err = register_netdev(dev_eql);
599	if (err)
600	free_netdev(dev_eql);
601	return err;
602	}
603
604	static void __exit eql_cleanup_module(void)
605	{
606	unregister_netdev(dev_eql);
607	free_netdev(dev_eql);
608	}
609
610	module_init(eql_init_module);
611	module_exit(eql_cleanup_module);
612	MODULE_LICENSE("GPL");