[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/capability.h>
#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 netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev);

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

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

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

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

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

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

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

static const char version[] __initconst =
	"Equalizer2002: Simon Janes ([email protected]) and David S. Miller ([email protected])\n";

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

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

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

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

	dev->netdev_ops		= &eql_netdev_ops;

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

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

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

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

	/* XXX We should force this off automatically for the user. */
	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 netdev_tx_t eql_slave_xmit(struct sk_buff *skb, struct net_device *dev)
{
	equalizer_t *eql = netdev_priv(dev);
	slave_t *slave;

	spin_lock(&eql->queue.lock);

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

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

	spin_unlock(&eql->queue.lock);

	return NETDEV_TX_OK;
}

/*
 *	Private ioctl functions
 */

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

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

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

	return NULL;
}

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

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

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

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

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

		return 0;
	}

	return -ENOSPC;
}

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

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

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

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

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

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

				return ret;
			}
		}
		dev_put(slave_dev);
	}

	return -EINVAL;
}

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

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

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

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

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

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

	return ret;
}

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

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

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

	ret = -EINVAL;

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

	dev_put(slave_dev);

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

	return ret;
}

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

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

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

	ret = -EINVAL;

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

	dev_put(slave_dev);

	return ret;
}

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

	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.
6aa20a22	11	*
1da177e4 LT	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:
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
d43c36dc	114	#include <linux/capability.h>
1da177e4 LT	115	#include <linux/module.h>
	116	#include <linux/kernel.h>
	117	#include <linux/init.h>
	118	#include <linux/timer.h>
	119	#include <linux/netdevice.h>
881d966b	120	#include <net/net_namespace.h>
1da177e4 LT	121
	122	#include <linux/if.h>
	123	#include <linux/if_arp.h>
	124	#include <linux/if_eql.h>
	125
	126	#include <asm/uaccess.h>
	127
	128	static int eql_open(struct net_device *dev);
	129	static int eql_close(struct net_device *dev);
	130	static int eql_ioctl(struct net_device dev, struct ifreq ifr, int cmd);
424efe9c	131	static netdev_tx_t eql_slave_xmit(struct sk_buff skb, struct net_device dev);
1da177e4 LT	132
	133	#define eql_is_slave(dev) ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
	134	#define eql_is_master(dev) ((dev->flags & IFF_MASTER) == IFF_MASTER)
	135
14a59e18	136	static void eql_kill_one_slave(slave_queue_t queue, slave_t slave);
1da177e4 LT	137
	138	static void eql_timer(unsigned long param)
	139	{
	140	equalizer_t eql = (equalizer_t ) param;
	141	struct list_head this, tmp, *head;
6aa20a22	142
1da177e4 LT	143	spin_lock_bh(&eql->queue.lock);
	144	head = &eql->queue.all_slaves;
	145	list_for_each_safe(this, tmp, head) {
	146	slave_t *slave = list_entry(this, slave_t, list);
	147
	148	if ((slave->dev->flags & IFF_UP) == IFF_UP) {
	149	slave->bytes_queued -= slave->priority_Bps;
	150	if (slave->bytes_queued < 0)
	151	slave->bytes_queued = 0;
	152	} else {
14a59e18	153	eql_kill_one_slave(&eql->queue, slave);
1da177e4 LT	154	}
	155
	156	}
	157	spin_unlock_bh(&eql->queue.lock);
	158
	159	eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
	160	add_timer(&eql->timer);
	161	}
	162
aec464bb	163	static const char version[] __initconst =
1da177e4 LT	164	"Equalizer2002: Simon Janes ([email protected]) and David S. Miller ([email protected])\n";
1da177e4 LT	165
99921b7e SH	166	static const struct net_device_ops eql_netdev_ops = {
	167	.ndo_open = eql_open,
	168	.ndo_stop = eql_close,
	169	.ndo_do_ioctl = eql_ioctl,
	170	.ndo_start_xmit = eql_slave_xmit,
	171	};
	172
1da177e4 LT	173	static void __init eql_setup(struct net_device *dev)
	174	{
	175	equalizer_t *eql = netdev_priv(dev);
	176
1da177e4 LT	177	init_timer(&eql->timer);
	178	eql->timer.data = (unsigned long) eql;
	179	eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
	180	eql->timer.function = eql_timer;
	181
	182	spin_lock_init(&eql->queue.lock);
	183	INIT_LIST_HEAD(&eql->queue.all_slaves);
	184	eql->queue.master_dev = dev;
	185
99921b7e	186	dev->netdev_ops = &eql_netdev_ops;
6aa20a22	187
1da177e4 LT	188	/*
1da177e4 LT	189	* Now we undo some of the things that eth_setup does
6aa20a22	190	* that we don't like
1da177e4	191	*/
6aa20a22	192
1da177e4 LT	193	dev->mtu = EQL_DEFAULT_MTU; /* set to 576 in if_eql.h */
	194	dev->flags = IFF_MASTER;
	195
	196	dev->type = ARPHRD_SLIP;
	197	dev->tx_queue_len = 5; /* Hands them off fast */
93f154b5	198	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1da177e4 LT	199	}
	200
	201	static int eql_open(struct net_device *dev)
	202	{
	203	equalizer_t *eql = netdev_priv(dev);
	204
	205	/* XXX We should force this off automatically for the user. */
	206	printk(KERN_INFO "%s: remember to turn off Van-Jacobson compression on "
	207	"your slave devices.\n", dev->name);
	208
5d9428de	209	BUG_ON(!list_empty(&eql->queue.all_slaves));
1da177e4 LT	210
	211	eql->min_slaves = 1;
	212	eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
	213
	214	add_timer(&eql->timer);
	215
	216	return 0;
	217	}
	218
14a59e18	219	static void eql_kill_one_slave(slave_queue_t queue, slave_t slave)
1da177e4 LT	220	{
1da177e4 LT	221	list_del(&slave->list);
14a59e18	222	queue->num_slaves--;
1da177e4 LT	223	slave->dev->flags &= ~IFF_SLAVE;
	224	dev_put(slave->dev);
	225	kfree(slave);
	226	}
	227
	228	static void eql_kill_slave_queue(slave_queue_t *queue)
6aa20a22	229	{
1da177e4 LT	230	struct list_head head, tmp, *this;
	231
	232	spin_lock_bh(&queue->lock);
	233
	234	head = &queue->all_slaves;
	235	list_for_each_safe(this, tmp, head) {
	236	slave_t *s = list_entry(this, slave_t, list);
	237
14a59e18	238	eql_kill_one_slave(queue, s);
1da177e4 LT	239	}
	240
	241	spin_unlock_bh(&queue->lock);
	242	}
	243
	244	static int eql_close(struct net_device *dev)
	245	{
	246	equalizer_t *eql = netdev_priv(dev);
	247
	248	/*
	249	* The timer has to be stopped first before we start hacking away
6aa20a22	250	* at the data structure it scans every so often...
1da177e4 LT	251	*/
	252
	253	del_timer_sync(&eql->timer);
	254
	255	eql_kill_slave_queue(&eql->queue);
	256
	257	return 0;
	258	}
	259
	260	static int eql_enslave(struct net_device dev, slaving_request_t __user srq);
	261	static int eql_emancipate(struct net_device dev, slaving_request_t __user srq);
	262
	263	static int eql_g_slave_cfg(struct net_device dev, slave_config_t __user sc);
	264	static int eql_s_slave_cfg(struct net_device dev, slave_config_t __user sc);
	265
	266	static int eql_g_master_cfg(struct net_device dev, master_config_t __user mc);
	267	static int eql_s_master_cfg(struct net_device dev, master_config_t __user mc);
	268
	269	static int eql_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
6aa20a22	270	{
1da177e4 LT	271	if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
	272	!capable(CAP_NET_ADMIN))
	273	return -EPERM;
	274
	275	switch (cmd) {
	276	case EQL_ENSLAVE:
	277	return eql_enslave(dev, ifr->ifr_data);
	278	case EQL_EMANCIPATE:
	279	return eql_emancipate(dev, ifr->ifr_data);
	280	case EQL_GETSLAVECFG:
	281	return eql_g_slave_cfg(dev, ifr->ifr_data);
	282	case EQL_SETSLAVECFG:
	283	return eql_s_slave_cfg(dev, ifr->ifr_data);
	284	case EQL_GETMASTRCFG:
	285	return eql_g_master_cfg(dev, ifr->ifr_data);
	286	case EQL_SETMASTRCFG:
	287	return eql_s_master_cfg(dev, ifr->ifr_data);
	288	default:
	289	return -EOPNOTSUPP;
	290	};
	291	}
	292
	293	/* queue->lock must be held */
	294	static slave_t __eql_schedule_slaves(slave_queue_t queue)
	295	{
	296	unsigned long best_load = ~0UL;
	297	struct list_head this, tmp, *head;
	298	slave_t *best_slave;
	299
	300	best_slave = NULL;
	301
	302	/* Make a pass to set the best slave. */
	303	head = &queue->all_slaves;
	304	list_for_each_safe(this, tmp, head) {
	305	slave_t *slave = list_entry(this, slave_t, list);
6aa20a22	306	unsigned long slave_load, bytes_queued, priority_Bps;
1da177e4 LT	307
	308	/* Go through the slave list once, updating best_slave
	309	* whenever a new best_load is found.
	310	*/
	311	bytes_queued = slave->bytes_queued;
6aa20a22	312	priority_Bps = slave->priority_Bps;
1da177e4	313	if ((slave->dev->flags & IFF_UP) == IFF_UP) {
6aa20a22	314	slave_load = (~0UL - (~0UL / 2)) -
1da177e4 LT	315	(priority_Bps) + bytes_queued * 8;
	316
	317	if (slave_load < best_load) {
	318	best_load = slave_load;
	319	best_slave = slave;
	320	}
	321	} else {
	322	/* We found a dead slave, kill it. */
14a59e18	323	eql_kill_one_slave(queue, slave);
1da177e4 LT	324	}
	325	}
	326	return best_slave;
	327	}
	328
424efe9c	329	static netdev_tx_t eql_slave_xmit(struct sk_buff skb, struct net_device dev)
1da177e4 LT	330	{
	331	equalizer_t *eql = netdev_priv(dev);
	332	slave_t *slave;
	333
	334	spin_lock(&eql->queue.lock);
	335
	336	slave = __eql_schedule_slaves(&eql->queue);
	337	if (slave) {
	338	struct net_device *slave_dev = slave->dev;
	339
	340	skb->dev = slave_dev;
	341	skb->priority = 1;
6aa20a22	342	slave->bytes_queued += skb->len;
1da177e4	343	dev_queue_xmit(skb);
09f75cd7	344	dev->stats.tx_packets++;
1da177e4	345	} else {
09f75cd7	346	dev->stats.tx_dropped++;
1da177e4	347	dev_kfree_skb(skb);
6aa20a22	348	}
1da177e4 LT	349
	350	spin_unlock(&eql->queue.lock);
	351
6ed10654	352	return NETDEV_TX_OK;
1da177e4 LT	353	}
1da177e4 LT	354
1da177e4 LT	355	/*
	356	* Private ioctl functions
	357	*/
	358
	359	/* queue->lock must be held */
	360	static slave_t __eql_find_slave_dev(slave_queue_t queue, struct net_device *dev)
	361	{
	362	struct list_head this, head;
	363
	364	head = &queue->all_slaves;
	365	list_for_each(this, head) {
	366	slave_t *slave = list_entry(this, slave_t, list);
	367
	368	if (slave->dev == dev)
	369	return slave;
	370	}
	371
	372	return NULL;
	373	}
	374
	375	static inline int eql_is_full(slave_queue_t *queue)
	376	{
	377	equalizer_t *eql = netdev_priv(queue->master_dev);
	378
	379	if (queue->num_slaves >= eql->max_slaves)
	380	return 1;
	381	return 0;
	382	}
	383
	384	/* queue->lock must be held */
	385	static int __eql_insert_slave(slave_queue_t queue, slave_t slave)
	386	{
	387	if (!eql_is_full(queue)) {
	388	slave_t *duplicate_slave = NULL;
	389
	390	duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
37d2e731	391	if (duplicate_slave)
14a59e18	392	eql_kill_one_slave(queue, duplicate_slave);
1da177e4 LT	393
	394	list_add(&slave->list, &queue->all_slaves);
	395	queue->num_slaves++;
	396	slave->dev->flags \|= IFF_SLAVE;
	397
	398	return 0;
	399	}
	400
	401	return -ENOSPC;
	402	}
	403
	404	static int eql_enslave(struct net_device master_dev, slaving_request_t __user srqp)
	405	{
	406	struct net_device *slave_dev;
	407	slaving_request_t srq;
	408
	409	if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
	410	return -EFAULT;
	411
881d966b	412	slave_dev = dev_get_by_name(&init_net, srq.slave_name);
1da177e4 LT	413	if (slave_dev) {
	414	if ((master_dev->flags & IFF_UP) == IFF_UP) {
	415	/* slave is not a master & not already a slave: */
	416	if (!eql_is_master(slave_dev) &&
	417	!eql_is_slave(slave_dev)) {
	418	slave_t s = kmalloc(sizeof(s), GFP_KERNEL);
	419	equalizer_t *eql = netdev_priv(master_dev);
	420	int ret;
	421
	422	if (!s) {
	423	dev_put(slave_dev);
	424	return -ENOMEM;
	425	}
	426
	427	memset(s, 0, sizeof(*s));
	428	s->dev = slave_dev;
	429	s->priority = srq.priority;
	430	s->priority_bps = srq.priority;
	431	s->priority_Bps = srq.priority / 8;
	432
	433	spin_lock_bh(&eql->queue.lock);
	434	ret = __eql_insert_slave(&eql->queue, s);
	435	if (ret) {
	436	dev_put(slave_dev);
	437	kfree(s);
	438	}
	439	spin_unlock_bh(&eql->queue.lock);
	440
	441	return ret;
	442	}
	443	}
	444	dev_put(slave_dev);
	445	}
	446
	447	return -EINVAL;
	448	}
	449
	450	static int eql_emancipate(struct net_device master_dev, slaving_request_t __user srqp)
	451	{
	452	equalizer_t *eql = netdev_priv(master_dev);
	453	struct net_device *slave_dev;
	454	slaving_request_t srq;
	455	int ret;
	456
	457	if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
	458	return -EFAULT;
	459
881d966b	460	slave_dev = dev_get_by_name(&init_net, srq.slave_name);
1da177e4 LT	461	ret = -EINVAL;
	462	if (slave_dev) {
	463	spin_lock_bh(&eql->queue.lock);
	464
	465	if (eql_is_slave(slave_dev)) {
	466	slave_t *slave = __eql_find_slave_dev(&eql->queue,
	467	slave_dev);
	468
	469	if (slave) {
14a59e18	470	eql_kill_one_slave(&eql->queue, slave);
1da177e4 LT	471	ret = 0;
	472	}
	473	}
	474	dev_put(slave_dev);
	475
	476	spin_unlock_bh(&eql->queue.lock);
	477	}
	478
	479	return ret;
	480	}
	481
	482	static 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
881d966b	493	slave_dev = dev_get_by_name(&init_net, sc.slave_name);
1da177e4 LT	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	dev_put(slave_dev);
	510
	511	if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
	512	ret = -EFAULT;
	513
	514	return ret;
	515	}
	516
	517	static int eql_s_slave_cfg(struct net_device dev, slave_config_t __user scp)
	518	{
	519	slave_t *slave;
	520	equalizer_t *eql;
	521	struct net_device *slave_dev;
	522	slave_config_t sc;
	523	int ret;
	524
	525	if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
	526	return -EFAULT;
	527
881d966b	528	slave_dev = dev_get_by_name(&init_net, sc.slave_name);
1da177e4 LT	529	if (!slave_dev)
	530	return -ENODEV;
	531
	532	ret = -EINVAL;
	533
	534	eql = netdev_priv(dev);
	535	spin_lock_bh(&eql->queue.lock);
	536	if (eql_is_slave(slave_dev)) {
	537	slave = __eql_find_slave_dev(&eql->queue, slave_dev);
	538	if (slave) {
	539	slave->priority = sc.priority;
	540	slave->priority_bps = sc.priority;
	541	slave->priority_Bps = sc.priority / 8;
	542	ret = 0;
	543	}
	544	}
	545	spin_unlock_bh(&eql->queue.lock);
	546
93889d75 YH	547	dev_put(slave_dev);
93889d75 YH	548
1da177e4 LT	549	return ret;
	550	}
	551
	552	static int eql_g_master_cfg(struct net_device dev, master_config_t __user mcp)
	553	{
	554	equalizer_t *eql;
	555	master_config_t mc;
	556
	557	if (eql_is_master(dev)) {
	558	eql = netdev_priv(dev);
	559	mc.max_slaves = eql->max_slaves;
	560	mc.min_slaves = eql->min_slaves;
	561	if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
	562	return -EFAULT;
	563	return 0;
	564	}
	565	return -EINVAL;
	566	}
	567
	568	static int eql_s_master_cfg(struct net_device dev, master_config_t __user mcp)
	569	{
	570	equalizer_t *eql;
	571	master_config_t mc;
	572
	573	if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
	574	return -EFAULT;
	575
	576	if (eql_is_master(dev)) {
	577	eql = netdev_priv(dev);
	578	eql->max_slaves = mc.max_slaves;
	579	eql->min_slaves = mc.min_slaves;
	580	return 0;
	581	}
	582	return -EINVAL;
	583	}
	584
	585	static struct net_device *dev_eql;
	586
	587	static int __init eql_init_module(void)
	588	{
	589	int err;
	590
	591	printk(version);
	592
	593	dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", eql_setup);
	594	if (!dev_eql)
	595	return -ENOMEM;
	596
	597	err = register_netdev(dev_eql);
6aa20a22	598	if (err)
1da177e4 LT	599	free_netdev(dev_eql);
	600	return err;
	601	}
	602
	603	static void __exit eql_cleanup_module(void)
	604	{
	605	unregister_netdev(dev_eql);
	606	free_netdev(dev_eql);
	607	}
	608
	609	module_init(eql_init_module);
	610	module_exit(eql_cleanup_module);
	611	MODULE_LICENSE("GPL");