[mirror_ubuntu-bionic-kernel.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
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

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

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

#include <linux/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(struct timer_list *t)
{
	equalizer_t *eql = from_timer(eql, t, timer);
	struct list_head *this, *tmp, *head;

	spin_lock(&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(&eql->queue.lock);

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

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

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

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

	timer_setup(&eql->timer, eql_timer, 0);
	eql->timer.expires  	= jiffies + EQL_DEFAULT_RESCHED_IVAL;

	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 */
	netif_keep_dst(dev);
}

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

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

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

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

	add_timer(&eql->timer);

	return 0;
}

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

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

	spin_lock_bh(&queue->lock);

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

		eql_kill_one_slave(queue, s);
	}

	spin_unlock_bh(&queue->lock);
}

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

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

	del_timer_sync(&eql->timer);

	eql_kill_slave_queue(&eql->queue);

	return 0;
}

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

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

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

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

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

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

	best_slave = NULL;

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

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

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

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

	spin_lock(&eql->queue.lock);

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

		skb->dev = slave_dev;
		skb->priority = TC_PRIO_FILLER;
		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);

		dev_hold(slave->dev);
		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)
		return -ENODEV;

	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)
				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)
				kfree(s);

			spin_unlock_bh(&eql->queue.lock);

			return ret;
		}
	}

	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);
	if (!slave_dev)
		return -ENODEV;

	ret = -EINVAL;
	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;
		}
	}
	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);

	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;

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

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

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

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

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

static struct net_device *dev_eql;

static int __init eql_init_module(void)
{
	int err;

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

	dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", NET_NAME_UNKNOWN,
			       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
63f97425 JP	114	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
63f97425 JP	115
d43c36dc	116	#include <linux/capability.h>
1da177e4 LT	117	#include <linux/module.h>
	118	#include <linux/kernel.h>
	119	#include <linux/init.h>
5a0e3ad6	120	#include <linux/slab.h>
1da177e4 LT	121	#include <linux/timer.h>
1da177e4 LT	122	#include <linux/netdevice.h>
881d966b	123	#include <net/net_namespace.h>
1da177e4 LT	124
	125	#include <linux/if.h>
	126	#include <linux/if_arp.h>
	127	#include <linux/if_eql.h>
09e79d6e	128	#include <linux/pkt_sched.h>
1da177e4	129
7c0f6ba6	130	#include <linux/uaccess.h>
1da177e4 LT	131
	132	static int eql_open(struct net_device *dev);
	133	static int eql_close(struct net_device *dev);
	134	static int eql_ioctl(struct net_device dev, struct ifreq ifr, int cmd);
424efe9c	135	static netdev_tx_t eql_slave_xmit(struct sk_buff skb, struct net_device dev);
1da177e4 LT	136
	137	#define eql_is_slave(dev) ((dev->flags & IFF_SLAVE) == IFF_SLAVE)
	138	#define eql_is_master(dev) ((dev->flags & IFF_MASTER) == IFF_MASTER)
	139
14a59e18	140	static void eql_kill_one_slave(slave_queue_t queue, slave_t slave);
1da177e4	141
e99e88a9	142	static void eql_timer(struct timer_list *t)
1da177e4	143	{
e99e88a9	144	equalizer_t *eql = from_timer(eql, t, timer);
1da177e4	145	struct list_head this, tmp, *head;
6aa20a22	146
09e79d6e	147	spin_lock(&eql->queue.lock);
1da177e4 LT	148	head = &eql->queue.all_slaves;
	149	list_for_each_safe(this, tmp, head) {
	150	slave_t *slave = list_entry(this, slave_t, list);
	151
	152	if ((slave->dev->flags & IFF_UP) == IFF_UP) {
	153	slave->bytes_queued -= slave->priority_Bps;
	154	if (slave->bytes_queued < 0)
	155	slave->bytes_queued = 0;
	156	} else {
14a59e18	157	eql_kill_one_slave(&eql->queue, slave);
1da177e4 LT	158	}
	159
	160	}
09e79d6e	161	spin_unlock(&eql->queue.lock);
1da177e4 LT	162
	163	eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
	164	add_timer(&eql->timer);
	165	}
	166
aec464bb	167	static const char version[] __initconst =
63f97425	168	"Equalizer2002: Simon Janes (simon@ncm.com) and David S. Miller (davem@redhat.com)";
1da177e4	169
99921b7e SH	170	static const struct net_device_ops eql_netdev_ops = {
	171	.ndo_open = eql_open,
	172	.ndo_stop = eql_close,
	173	.ndo_do_ioctl = eql_ioctl,
	174	.ndo_start_xmit = eql_slave_xmit,
	175	};
	176
1da177e4 LT	177	static void __init eql_setup(struct net_device *dev)
	178	{
	179	equalizer_t *eql = netdev_priv(dev);
	180
e99e88a9	181	timer_setup(&eql->timer, eql_timer, 0);
1da177e4	182	eql->timer.expires = jiffies + EQL_DEFAULT_RESCHED_IVAL;
1da177e4 LT	183
	184	spin_lock_init(&eql->queue.lock);
	185	INIT_LIST_HEAD(&eql->queue.all_slaves);
	186	eql->queue.master_dev = dev;
	187
99921b7e	188	dev->netdev_ops = &eql_netdev_ops;
6aa20a22	189
1da177e4 LT	190	/*
1da177e4 LT	191	* Now we undo some of the things that eth_setup does
6aa20a22	192	* that we don't like
1da177e4	193	*/
6aa20a22	194
1da177e4 LT	195	dev->mtu = EQL_DEFAULT_MTU; /* set to 576 in if_eql.h */
	196	dev->flags = IFF_MASTER;
	197
	198	dev->type = ARPHRD_SLIP;
	199	dev->tx_queue_len = 5; /* Hands them off fast */
02875878	200	netif_keep_dst(dev);
1da177e4 LT	201	}
	202
	203	static int eql_open(struct net_device *dev)
	204	{
	205	equalizer_t *eql = netdev_priv(dev);
	206
	207	/* XXX We should force this off automatically for the user. */
63f97425 JP	208	netdev_info(dev,
63f97425 JP	209	"remember to turn off Van-Jacobson compression on your slave devices\n");
1da177e4	210
5d9428de	211	BUG_ON(!list_empty(&eql->queue.all_slaves));
1da177e4 LT	212
	213	eql->min_slaves = 1;
	214	eql->max_slaves = EQL_DEFAULT_MAX_SLAVES; /* 4 usually... */
	215
	216	add_timer(&eql->timer);
	217
	218	return 0;
	219	}
	220
14a59e18	221	static void eql_kill_one_slave(slave_queue_t queue, slave_t slave)
1da177e4 LT	222	{
1da177e4 LT	223	list_del(&slave->list);
14a59e18	224	queue->num_slaves--;
1da177e4 LT	225	slave->dev->flags &= ~IFF_SLAVE;
	226	dev_put(slave->dev);
	227	kfree(slave);
	228	}
	229
	230	static void eql_kill_slave_queue(slave_queue_t *queue)
6aa20a22	231	{
1da177e4 LT	232	struct list_head head, tmp, *this;
	233
	234	spin_lock_bh(&queue->lock);
	235
	236	head = &queue->all_slaves;
	237	list_for_each_safe(this, tmp, head) {
	238	slave_t *s = list_entry(this, slave_t, list);
	239
14a59e18	240	eql_kill_one_slave(queue, s);
1da177e4 LT	241	}
	242
	243	spin_unlock_bh(&queue->lock);
	244	}
	245
	246	static int eql_close(struct net_device *dev)
	247	{
	248	equalizer_t *eql = netdev_priv(dev);
	249
	250	/*
	251	* The timer has to be stopped first before we start hacking away
6aa20a22	252	* at the data structure it scans every so often...
1da177e4 LT	253	*/
	254
	255	del_timer_sync(&eql->timer);
	256
	257	eql_kill_slave_queue(&eql->queue);
	258
	259	return 0;
	260	}
	261
	262	static int eql_enslave(struct net_device dev, slaving_request_t __user srq);
	263	static int eql_emancipate(struct net_device dev, slaving_request_t __user srq);
	264
	265	static int eql_g_slave_cfg(struct net_device dev, slave_config_t __user sc);
	266	static int eql_s_slave_cfg(struct net_device dev, slave_config_t __user sc);
	267
	268	static int eql_g_master_cfg(struct net_device dev, master_config_t __user mc);
	269	static int eql_s_master_cfg(struct net_device dev, master_config_t __user mc);
	270
	271	static int eql_ioctl(struct net_device dev, struct ifreq ifr, int cmd)
6aa20a22	272	{
1da177e4 LT	273	if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&
	274	!capable(CAP_NET_ADMIN))
	275	return -EPERM;
	276
	277	switch (cmd) {
	278	case EQL_ENSLAVE:
	279	return eql_enslave(dev, ifr->ifr_data);
	280	case EQL_EMANCIPATE:
	281	return eql_emancipate(dev, ifr->ifr_data);
	282	case EQL_GETSLAVECFG:
	283	return eql_g_slave_cfg(dev, ifr->ifr_data);
	284	case EQL_SETSLAVECFG:
	285	return eql_s_slave_cfg(dev, ifr->ifr_data);
	286	case EQL_GETMASTRCFG:
	287	return eql_g_master_cfg(dev, ifr->ifr_data);
	288	case EQL_SETMASTRCFG:
	289	return eql_s_master_cfg(dev, ifr->ifr_data);
	290	default:
	291	return -EOPNOTSUPP;
ee289b64	292	}
1da177e4 LT	293	}
	294
	295	/* queue->lock must be held */
	296	static slave_t __eql_schedule_slaves(slave_queue_t queue)
	297	{
	298	unsigned long best_load = ~0UL;
	299	struct list_head this, tmp, *head;
	300	slave_t *best_slave;
	301
	302	best_slave = NULL;
	303
	304	/* Make a pass to set the best slave. */
	305	head = &queue->all_slaves;
	306	list_for_each_safe(this, tmp, head) {
	307	slave_t *slave = list_entry(this, slave_t, list);
6aa20a22	308	unsigned long slave_load, bytes_queued, priority_Bps;
1da177e4 LT	309
	310	/* Go through the slave list once, updating best_slave
	311	* whenever a new best_load is found.
	312	*/
	313	bytes_queued = slave->bytes_queued;
6aa20a22	314	priority_Bps = slave->priority_Bps;
1da177e4	315	if ((slave->dev->flags & IFF_UP) == IFF_UP) {
6aa20a22	316	slave_load = (~0UL - (~0UL / 2)) -
1da177e4 LT	317	(priority_Bps) + bytes_queued * 8;
	318
	319	if (slave_load < best_load) {
	320	best_load = slave_load;
	321	best_slave = slave;
	322	}
	323	} else {
	324	/* We found a dead slave, kill it. */
14a59e18	325	eql_kill_one_slave(queue, slave);
1da177e4 LT	326	}
	327	}
	328	return best_slave;
	329	}
	330
424efe9c	331	static netdev_tx_t eql_slave_xmit(struct sk_buff skb, struct net_device dev)
1da177e4 LT	332	{
	333	equalizer_t *eql = netdev_priv(dev);
	334	slave_t *slave;
	335
	336	spin_lock(&eql->queue.lock);
	337
	338	slave = __eql_schedule_slaves(&eql->queue);
	339	if (slave) {
	340	struct net_device *slave_dev = slave->dev;
	341
	342	skb->dev = slave_dev;
09e79d6e	343	skb->priority = TC_PRIO_FILLER;
6aa20a22	344	slave->bytes_queued += skb->len;
1da177e4	345	dev_queue_xmit(skb);
09f75cd7	346	dev->stats.tx_packets++;
1da177e4	347	} else {
09f75cd7	348	dev->stats.tx_dropped++;
1da177e4	349	dev_kfree_skb(skb);
6aa20a22	350	}
1da177e4 LT	351
	352	spin_unlock(&eql->queue.lock);
	353
6ed10654	354	return NETDEV_TX_OK;
1da177e4 LT	355	}
1da177e4 LT	356
1da177e4 LT	357	/*
	358	* Private ioctl functions
	359	*/
	360
	361	/* queue->lock must be held */
	362	static slave_t __eql_find_slave_dev(slave_queue_t queue, struct net_device *dev)
	363	{
	364	struct list_head this, head;
	365
	366	head = &queue->all_slaves;
	367	list_for_each(this, head) {
	368	slave_t *slave = list_entry(this, slave_t, list);
	369
	370	if (slave->dev == dev)
	371	return slave;
	372	}
	373
	374	return NULL;
	375	}
	376
	377	static inline int eql_is_full(slave_queue_t *queue)
	378	{
	379	equalizer_t *eql = netdev_priv(queue->master_dev);
	380
	381	if (queue->num_slaves >= eql->max_slaves)
	382	return 1;
	383	return 0;
	384	}
	385
	386	/* queue->lock must be held */
	387	static int __eql_insert_slave(slave_queue_t queue, slave_t slave)
	388	{
	389	if (!eql_is_full(queue)) {
	390	slave_t *duplicate_slave = NULL;
	391
	392	duplicate_slave = __eql_find_slave_dev(queue, slave->dev);
37d2e731	393	if (duplicate_slave)
14a59e18	394	eql_kill_one_slave(queue, duplicate_slave);
1da177e4	395
ebd93a7d	396	dev_hold(slave->dev);
1da177e4 LT	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
ebd93a7d YX	415	slave_dev = __dev_get_by_name(&init_net, srq.slave_name);
	416	if (!slave_dev)
	417	return -ENODEV;
	418
	419	if ((master_dev->flags & IFF_UP) == IFF_UP) {
	420	/* slave is not a master & not already a slave: */
	421	if (!eql_is_master(slave_dev) && !eql_is_slave(slave_dev)) {
	422	slave_t s = kmalloc(sizeof(s), GFP_KERNEL);
	423	equalizer_t *eql = netdev_priv(master_dev);
	424	int ret;
	425
	426	if (!s)
	427	return -ENOMEM;
	428
	429	memset(s, 0, sizeof(*s));
	430	s->dev = slave_dev;
	431	s->priority = srq.priority;
	432	s->priority_bps = srq.priority;
	433	s->priority_Bps = srq.priority / 8;
	434
	435	spin_lock_bh(&eql->queue.lock);
	436	ret = __eql_insert_slave(&eql->queue, s);
	437	if (ret)
	438	kfree(s);
	439
	440	spin_unlock_bh(&eql->queue.lock);
	441
	442	return ret;
1da177e4	443	}
1da177e4 LT	444	}
	445
	446	return -EINVAL;
	447	}
	448
	449	static int eql_emancipate(struct net_device master_dev, slaving_request_t __user srqp)
	450	{
	451	equalizer_t *eql = netdev_priv(master_dev);
	452	struct net_device *slave_dev;
	453	slaving_request_t srq;
	454	int ret;
	455
	456	if (copy_from_user(&srq, srqp, sizeof (slaving_request_t)))
	457	return -EFAULT;
	458
ebd93a7d YX	459	slave_dev = __dev_get_by_name(&init_net, srq.slave_name);
	460	if (!slave_dev)
	461	return -ENODEV;
1da177e4	462
ebd93a7d YX	463	ret = -EINVAL;
	464	spin_lock_bh(&eql->queue.lock);
	465	if (eql_is_slave(slave_dev)) {
	466	slave_t *slave = __eql_find_slave_dev(&eql->queue, slave_dev);
	467	if (slave) {
	468	eql_kill_one_slave(&eql->queue, slave);
	469	ret = 0;
1da177e4	470	}
1da177e4	471	}
ebd93a7d	472	spin_unlock_bh(&eql->queue.lock);
1da177e4 LT	473
	474	return ret;
	475	}
	476
	477	static int eql_g_slave_cfg(struct net_device dev, slave_config_t __user scp)
	478	{
	479	equalizer_t *eql = netdev_priv(dev);
	480	slave_t *slave;
	481	struct net_device *slave_dev;
	482	slave_config_t sc;
	483	int ret;
	484
	485	if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
	486	return -EFAULT;
	487
ebd93a7d	488	slave_dev = __dev_get_by_name(&init_net, sc.slave_name);
1da177e4 LT	489	if (!slave_dev)
	490	return -ENODEV;
	491
	492	ret = -EINVAL;
	493
	494	spin_lock_bh(&eql->queue.lock);
	495	if (eql_is_slave(slave_dev)) {
	496	slave = __eql_find_slave_dev(&eql->queue, slave_dev);
	497	if (slave) {
	498	sc.priority = slave->priority;
	499	ret = 0;
	500	}
	501	}
	502	spin_unlock_bh(&eql->queue.lock);
	503
1da177e4 LT	504	if (!ret && copy_to_user(scp, &sc, sizeof (slave_config_t)))
	505	ret = -EFAULT;
	506
	507	return ret;
	508	}
	509
	510	static int eql_s_slave_cfg(struct net_device dev, slave_config_t __user scp)
	511	{
	512	slave_t *slave;
	513	equalizer_t *eql;
	514	struct net_device *slave_dev;
	515	slave_config_t sc;
	516	int ret;
	517
	518	if (copy_from_user(&sc, scp, sizeof (slave_config_t)))
	519	return -EFAULT;
	520
ebd93a7d	521	slave_dev = __dev_get_by_name(&init_net, sc.slave_name);
1da177e4 LT	522	if (!slave_dev)
	523	return -ENODEV;
	524
	525	ret = -EINVAL;
	526
	527	eql = netdev_priv(dev);
	528	spin_lock_bh(&eql->queue.lock);
	529	if (eql_is_slave(slave_dev)) {
	530	slave = __eql_find_slave_dev(&eql->queue, slave_dev);
	531	if (slave) {
	532	slave->priority = sc.priority;
	533	slave->priority_bps = sc.priority;
	534	slave->priority_Bps = sc.priority / 8;
	535	ret = 0;
	536	}
	537	}
	538	spin_unlock_bh(&eql->queue.lock);
	539
	540	return ret;
	541	}
	542
	543	static int eql_g_master_cfg(struct net_device dev, master_config_t __user mcp)
	544	{
	545	equalizer_t *eql;
	546	master_config_t mc;
	547
44467187 DR	548	memset(&mc, 0, sizeof(master_config_t));
44467187 DR	549
1da177e4 LT	550	if (eql_is_master(dev)) {
	551	eql = netdev_priv(dev);
	552	mc.max_slaves = eql->max_slaves;
	553	mc.min_slaves = eql->min_slaves;
	554	if (copy_to_user(mcp, &mc, sizeof (master_config_t)))
	555	return -EFAULT;
	556	return 0;
	557	}
	558	return -EINVAL;
	559	}
	560
	561	static int eql_s_master_cfg(struct net_device dev, master_config_t __user mcp)
	562	{
	563	equalizer_t *eql;
	564	master_config_t mc;
	565
	566	if (copy_from_user(&mc, mcp, sizeof (master_config_t)))
	567	return -EFAULT;
	568
	569	if (eql_is_master(dev)) {
	570	eql = netdev_priv(dev);
	571	eql->max_slaves = mc.max_slaves;
	572	eql->min_slaves = mc.min_slaves;
	573	return 0;
	574	}
	575	return -EINVAL;
	576	}
	577
	578	static struct net_device *dev_eql;
	579
	580	static int __init eql_init_module(void)
	581	{
	582	int err;
	583
63f97425	584	pr_info("%s\n", version);
1da177e4	585
c835a677 TG	586	dev_eql = alloc_netdev(sizeof(equalizer_t), "eql", NET_NAME_UNKNOWN,
c835a677 TG	587	eql_setup);
1da177e4 LT	588	if (!dev_eql)
	589	return -ENOMEM;
	590
	591	err = register_netdev(dev_eql);
6aa20a22	592	if (err)
1da177e4 LT	593	free_netdev(dev_eql);
	594	return err;
	595	}
	596
	597	static void __exit eql_cleanup_module(void)
	598	{
	599	unregister_netdev(dev_eql);
	600	free_netdev(dev_eql);
	601	}
	602
	603	module_init(eql_init_module);
	604	module_exit(eql_cleanup_module);
	605	MODULE_LICENSE("GPL");