/* * 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/compat.h>#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_siocdevprivate(struct net_device *dev, struct ifreq *ifr,			      void __user *data, 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 = timer_container_of(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_siocdevprivate = eql_siocdevprivate,	.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;	netdev_put(slave->dev, &slave->dev_tracker);	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...	 */ 	timer_delete_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_siocdevprivate(struct net_device *dev, struct ifreq *ifr,			      void __user *data, int cmd){	if (cmd != EQL_GETMASTRCFG && cmd != EQL_GETSLAVECFG &&	    !capable(CAP_NET_ADMIN))	  	return -EPERM; 	if (in_compat_syscall()) /* to be implemented */		return -EOPNOTSUPP; 	switch (cmd) {		case EQL_ENSLAVE:			return eql_enslave(dev, data);		case EQL_EMANCIPATE:			return eql_emancipate(dev, data);		case EQL_GETSLAVECFG:			return eql_g_slave_cfg(dev, data);		case EQL_SETSLAVECFG:			return eql_s_slave_cfg(dev, data);		case EQL_GETMASTRCFG:			return eql_g_master_cfg(dev, data);		case EQL_SETMASTRCFG:			return eql_s_master_cfg(dev, 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); 		netdev_hold(slave->dev, &slave->dev_tracker, GFP_ATOMIC);		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 = kzalloc_obj(*s);			equalizer_t *eql = netdev_priv(master_dev);			int ret; 			if (!s)				return -ENOMEM; 			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)) {

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