[linux-2.6-block.git] / net / sched / sch_teql.c

/* net/sched/sch_teql.c	"True" (or "trivial") link equalizer.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/if_arp.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/moduleparam.h>
#include <net/dst.h>
#include <net/neighbour.h>
#include <net/pkt_sched.h>

/*
   How to setup it.
   ----------------

   After loading this module you will find a new device teqlN
   and new qdisc with the same name. To join a slave to the equalizer
   you should just set this qdisc on a device f.e.

   # tc qdisc add dev eth0 root teql0
   # tc qdisc add dev eth1 root teql0

   That's all. Full PnP 8)

   Applicability.
   --------------

   1. Slave devices MUST be active devices, i.e., they must raise the tbusy
      signal and generate EOI events. If you want to equalize virtual devices
      like tunnels, use a normal eql device.
   2. This device puts no limitations on physical slave characteristics
      f.e. it will equalize 9600baud line and 100Mb ethernet perfectly :-)
      Certainly, large difference in link speeds will make the resulting
      eqalized link unusable, because of huge packet reordering.
      I estimate an upper useful difference as ~10 times.
   3. If the slave requires address resolution, only protocols using
      neighbour cache (IPv4/IPv6) will work over the equalized link.
      Other protocols are still allowed to use the slave device directly,
      which will not break load balancing, though native slave
      traffic will have the highest priority.  */

struct teql_master
{
	struct Qdisc_ops qops;
	struct net_device *dev;
	struct Qdisc *slaves;
	struct list_head master_list;
	struct net_device_stats stats;
};

struct teql_sched_data
{
	struct Qdisc *next;
	struct teql_master *m;
	struct neighbour *ncache;
	struct sk_buff_head q;
};

#define NEXT_SLAVE(q) (((struct teql_sched_data*)qdisc_priv(q))->next)

#define FMASK (IFF_BROADCAST|IFF_POINTOPOINT)

/* "teql*" qdisc routines */

static int
teql_enqueue(struct sk_buff *skb, struct Qdisc* sch)
{
	struct net_device *dev = qdisc_dev(sch);
	struct teql_sched_data *q = qdisc_priv(sch);

	if (q->q.qlen < dev->tx_queue_len) {
		__skb_queue_tail(&q->q, skb);
		sch->bstats.bytes += skb->len;
		sch->bstats.packets++;
		return 0;
	}

	kfree_skb(skb);
	sch->qstats.drops++;
	return NET_XMIT_DROP;
}

static int
teql_requeue(struct sk_buff *skb, struct Qdisc* sch)
{
	struct teql_sched_data *q = qdisc_priv(sch);

	__skb_queue_head(&q->q, skb);
	sch->qstats.requeues++;
	return 0;
}

static struct sk_buff *
teql_dequeue(struct Qdisc* sch)
{
	struct teql_sched_data *dat = qdisc_priv(sch);
	struct netdev_queue *dat_queue;
	struct sk_buff *skb;

	skb = __skb_dequeue(&dat->q);
	dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
	if (skb == NULL) {
		struct net_device *m = qdisc_dev(dat_queue->qdisc);
		if (m) {
			dat->m->slaves = sch;
			netif_wake_queue(m);
		}
	}
	sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen;
	return skb;
}

static __inline__ void
teql_neigh_release(struct neighbour *n)
{
	if (n)
		neigh_release(n);
}

static void
teql_reset(struct Qdisc* sch)
{
	struct teql_sched_data *dat = qdisc_priv(sch);

	skb_queue_purge(&dat->q);
	sch->q.qlen = 0;
	teql_neigh_release(xchg(&dat->ncache, NULL));
}

static void
teql_destroy(struct Qdisc* sch)
{
	struct Qdisc *q, *prev;
	struct teql_sched_data *dat = qdisc_priv(sch);
	struct teql_master *master = dat->m;

	if ((prev = master->slaves) != NULL) {
		do {
			q = NEXT_SLAVE(prev);
			if (q == sch) {
				NEXT_SLAVE(prev) = NEXT_SLAVE(q);
				if (q == master->slaves) {
					master->slaves = NEXT_SLAVE(q);
					if (q == master->slaves) {
						struct netdev_queue *txq;
						spinlock_t *root_lock;

						txq = netdev_get_tx_queue(master->dev, 0);
						master->slaves = NULL;

						root_lock = qdisc_root_lock(txq->qdisc);
						spin_lock_bh(root_lock);
						qdisc_reset(txq->qdisc);
						spin_unlock_bh(root_lock);
					}
				}
				skb_queue_purge(&dat->q);
				teql_neigh_release(xchg(&dat->ncache, NULL));
				break;
			}

		} while ((prev = q) != master->slaves);
	}
}

static int teql_qdisc_init(struct Qdisc *sch, struct nlattr *opt)
{
	struct net_device *dev = qdisc_dev(sch);
	struct teql_master *m = (struct teql_master*)sch->ops;
	struct teql_sched_data *q = qdisc_priv(sch);

	if (dev->hard_header_len > m->dev->hard_header_len)
		return -EINVAL;

	if (m->dev == dev)
		return -ELOOP;

	q->m = m;

	skb_queue_head_init(&q->q);

	if (m->slaves) {
		if (m->dev->flags & IFF_UP) {
			if ((m->dev->flags&IFF_POINTOPOINT && !(dev->flags&IFF_POINTOPOINT))
			    || (m->dev->flags&IFF_BROADCAST && !(dev->flags&IFF_BROADCAST))
			    || (m->dev->flags&IFF_MULTICAST && !(dev->flags&IFF_MULTICAST))
			    || dev->mtu < m->dev->mtu)
				return -EINVAL;
		} else {
			if (!(dev->flags&IFF_POINTOPOINT))
				m->dev->flags &= ~IFF_POINTOPOINT;
			if (!(dev->flags&IFF_BROADCAST))
				m->dev->flags &= ~IFF_BROADCAST;
			if (!(dev->flags&IFF_MULTICAST))
				m->dev->flags &= ~IFF_MULTICAST;
			if (dev->mtu < m->dev->mtu)
				m->dev->mtu = dev->mtu;
		}
		q->next = NEXT_SLAVE(m->slaves);
		NEXT_SLAVE(m->slaves) = sch;
	} else {
		q->next = sch;
		m->slaves = sch;
		m->dev->mtu = dev->mtu;
		m->dev->flags = (m->dev->flags&~FMASK)|(dev->flags&FMASK);
	}
	return 0;
}


static int
__teql_resolve(struct sk_buff *skb, struct sk_buff *skb_res, struct net_device *dev)
{
	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);
	struct neighbour *mn = skb->dst->neighbour;
	struct neighbour *n = q->ncache;

	if (mn->tbl == NULL)
		return -EINVAL;
	if (n && n->tbl == mn->tbl &&
	    memcmp(n->primary_key, mn->primary_key, mn->tbl->key_len) == 0) {
		atomic_inc(&n->refcnt);
	} else {
		n = __neigh_lookup_errno(mn->tbl, mn->primary_key, dev);
		if (IS_ERR(n))
			return PTR_ERR(n);
	}
	if (neigh_event_send(n, skb_res) == 0) {
		int err;

		read_lock(&n->lock);
		err = dev_hard_header(skb, dev, ntohs(skb->protocol),
				      n->ha, NULL, skb->len);
		read_unlock(&n->lock);

		if (err < 0) {
			neigh_release(n);
			return -EINVAL;
		}
		teql_neigh_release(xchg(&q->ncache, n));
		return 0;
	}
	neigh_release(n);
	return (skb_res == NULL) ? -EAGAIN : 1;
}

static inline int teql_resolve(struct sk_buff *skb,
			       struct sk_buff *skb_res, struct net_device *dev)
{
	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
	if (txq->qdisc == &noop_qdisc)
		return -ENODEV;

	if (dev->header_ops == NULL ||
	    skb->dst == NULL ||
	    skb->dst->neighbour == NULL)
		return 0;
	return __teql_resolve(skb, skb_res, dev);
}

static int teql_master_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct teql_master *master = netdev_priv(dev);
	struct Qdisc *start, *q;
	int busy;
	int nores;
	int len = skb->len;
	int subq = skb_get_queue_mapping(skb);
	struct sk_buff *skb_res = NULL;

	start = master->slaves;

restart:
	nores = 0;
	busy = 0;

	if ((q = start) == NULL)
		goto drop;

	do {
		struct net_device *slave = qdisc_dev(q);
		struct netdev_queue *slave_txq;

		slave_txq = netdev_get_tx_queue(slave, 0);
		if (slave_txq->qdisc_sleeping != q)
			continue;
		if (__netif_subqueue_stopped(slave, subq) ||
		    !netif_running(slave)) {
			busy = 1;
			continue;
		}

		switch (teql_resolve(skb, skb_res, slave)) {
		case 0:
			if (netif_tx_trylock(slave)) {
				if (!__netif_subqueue_stopped(slave, subq) &&
				    slave->hard_start_xmit(skb, slave) == 0) {
					netif_tx_unlock(slave);
					master->slaves = NEXT_SLAVE(q);
					netif_wake_queue(dev);
					master->stats.tx_packets++;
					master->stats.tx_bytes += len;
					return 0;
				}
				netif_tx_unlock(slave);
			}
			if (netif_queue_stopped(dev))
				busy = 1;
			break;
		case 1:
			master->slaves = NEXT_SLAVE(q);
			return 0;
		default:
			nores = 1;
			break;
		}
		__skb_pull(skb, skb_network_offset(skb));
	} while ((q = NEXT_SLAVE(q)) != start);

	if (nores && skb_res == NULL) {
		skb_res = skb;
		goto restart;
	}

	if (busy) {
		netif_stop_queue(dev);
		return 1;
	}
	master->stats.tx_errors++;

drop:
	master->stats.tx_dropped++;
	dev_kfree_skb(skb);
	return 0;
}

static int teql_master_open(struct net_device *dev)
{
	struct Qdisc * q;
	struct teql_master *m = netdev_priv(dev);
	int mtu = 0xFFFE;
	unsigned flags = IFF_NOARP|IFF_MULTICAST;

	if (m->slaves == NULL)
		return -EUNATCH;

	flags = FMASK;

	q = m->slaves;
	do {
		struct net_device *slave = qdisc_dev(q);

		if (slave == NULL)
			return -EUNATCH;

		if (slave->mtu < mtu)
			mtu = slave->mtu;
		if (slave->hard_header_len > LL_MAX_HEADER)
			return -EINVAL;

		/* If all the slaves are BROADCAST, master is BROADCAST
		   If all the slaves are PtP, master is PtP
		   Otherwise, master is NBMA.
		 */
		if (!(slave->flags&IFF_POINTOPOINT))
			flags &= ~IFF_POINTOPOINT;
		if (!(slave->flags&IFF_BROADCAST))
			flags &= ~IFF_BROADCAST;
		if (!(slave->flags&IFF_MULTICAST))
			flags &= ~IFF_MULTICAST;
	} while ((q = NEXT_SLAVE(q)) != m->slaves);

	m->dev->mtu = mtu;
	m->dev->flags = (m->dev->flags&~FMASK) | flags;
	netif_start_queue(m->dev);
	return 0;
}

static int teql_master_close(struct net_device *dev)
{
	netif_stop_queue(dev);
	return 0;
}

static struct net_device_stats *teql_master_stats(struct net_device *dev)
{
	struct teql_master *m = netdev_priv(dev);
	return &m->stats;
}

static int teql_master_mtu(struct net_device *dev, int new_mtu)
{
	struct teql_master *m = netdev_priv(dev);
	struct Qdisc *q;

	if (new_mtu < 68)
		return -EINVAL;

	q = m->slaves;
	if (q) {
		do {
			if (new_mtu > qdisc_dev(q)->mtu)
				return -EINVAL;
		} while ((q=NEXT_SLAVE(q)) != m->slaves);
	}

	dev->mtu = new_mtu;
	return 0;
}

static __init void teql_master_setup(struct net_device *dev)
{
	struct teql_master *master = netdev_priv(dev);
	struct Qdisc_ops *ops = &master->qops;

	master->dev	= dev;
	ops->priv_size  = sizeof(struct teql_sched_data);

	ops->enqueue	=	teql_enqueue;
	ops->dequeue	=	teql_dequeue;
	ops->requeue	=	teql_requeue;
	ops->init	=	teql_qdisc_init;
	ops->reset	=	teql_reset;
	ops->destroy	=	teql_destroy;
	ops->owner	=	THIS_MODULE;

	dev->open		= teql_master_open;
	dev->hard_start_xmit	= teql_master_xmit;
	dev->stop		= teql_master_close;
	dev->get_stats		= teql_master_stats;
	dev->change_mtu		= teql_master_mtu;
	dev->type		= ARPHRD_VOID;
	dev->mtu		= 1500;
	dev->tx_queue_len	= 100;
	dev->flags		= IFF_NOARP;
	dev->hard_header_len	= LL_MAX_HEADER;
}

static LIST_HEAD(master_dev_list);
static int max_equalizers = 1;
module_param(max_equalizers, int, 0);
MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");

static int __init teql_init(void)
{
	int i;
	int err = -ENODEV;

	for (i = 0; i < max_equalizers; i++) {
		struct net_device *dev;
		struct teql_master *master;

		dev = alloc_netdev(sizeof(struct teql_master),
				  "teql%d", teql_master_setup);
		if (!dev) {
			err = -ENOMEM;
			break;
		}

		if ((err = register_netdev(dev))) {
			free_netdev(dev);
			break;
		}

		master = netdev_priv(dev);

		strlcpy(master->qops.id, dev->name, IFNAMSIZ);
		err = register_qdisc(&master->qops);

		if (err) {
			unregister_netdev(dev);
			free_netdev(dev);
			break;
		}

		list_add_tail(&master->master_list, &master_dev_list);
	}
	return i ? 0 : err;
}

static void __exit teql_exit(void)
{
	struct teql_master *master, *nxt;

	list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {

		list_del(&master->master_list);

		unregister_qdisc(&master->qops);
		unregister_netdev(master->dev);
		free_netdev(master->dev);
	}
}

module_init(teql_init);
module_exit(teql_exit);

MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/* net/sched/sch_teql.c "True" (or "trivial") link equalizer.
	2	*
	3	* This program is free software; you can redistribute it and/or
	4	* modify it under the terms of the GNU General Public License
	5	* as published by the Free Software Foundation; either version
	6	* 2 of the License, or (at your option) any later version.
	7	*
	8	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	9	*/
	10
	11	#include <linux/module.h>
1da177e4 LT	12	#include <linux/types.h>
1da177e4 LT	13	#include <linux/kernel.h>
1da177e4	14	#include <linux/string.h>
1da177e4	15	#include <linux/errno.h>
14c85021	16	#include <linux/if_arp.h>
1da177e4	17	#include <linux/netdevice.h>
1da177e4	18	#include <linux/init.h>
1da177e4 LT	19	#include <linux/skbuff.h>
1da177e4 LT	20	#include <linux/moduleparam.h>
0ba48053 PM	21	#include <net/dst.h>
0ba48053 PM	22	#include <net/neighbour.h>
1da177e4 LT	23	#include <net/pkt_sched.h>
	24
	25	/*
	26	How to setup it.
	27	----------------
	28
	29	After loading this module you will find a new device teqlN
	30	and new qdisc with the same name. To join a slave to the equalizer
	31	you should just set this qdisc on a device f.e.
	32
	33	# tc qdisc add dev eth0 root teql0
	34	# tc qdisc add dev eth1 root teql0
	35
	36	That's all. Full PnP 8)
	37
	38	Applicability.
	39	--------------
	40
	41	1. Slave devices MUST be active devices, i.e., they must raise the tbusy
	42	signal and generate EOI events. If you want to equalize virtual devices
	43	like tunnels, use a normal eql device.
	44	2. This device puts no limitations on physical slave characteristics
	45	f.e. it will equalize 9600baud line and 100Mb ethernet perfectly :-)
	46	Certainly, large difference in link speeds will make the resulting
	47	eqalized link unusable, because of huge packet reordering.
	48	I estimate an upper useful difference as ~10 times.
	49	3. If the slave requires address resolution, only protocols using
	50	neighbour cache (IPv4/IPv6) will work over the equalized link.
	51	Other protocols are still allowed to use the slave device directly,
	52	which will not break load balancing, though native slave
	53	traffic will have the highest priority. */
	54
	55	struct teql_master
	56	{
	57	struct Qdisc_ops qops;
	58	struct net_device *dev;
	59	struct Qdisc *slaves;
	60	struct list_head master_list;
	61	struct net_device_stats stats;
	62	};
	63
	64	struct teql_sched_data
	65	{
	66	struct Qdisc *next;
	67	struct teql_master *m;
	68	struct neighbour *ncache;
	69	struct sk_buff_head q;
	70	};
	71
	72	#define NEXT_SLAVE(q) (((struct teql_sched_data*)qdisc_priv(q))->next)
	73
cc8fd14d	74	#define FMASK (IFF_BROADCAST\|IFF_POINTOPOINT)
1da177e4 LT	75
	76	/* "teql" qdisc routines /
	77
	78	static int
	79	teql_enqueue(struct sk_buff skb, struct Qdisc sch)
	80	{
5ce2d488	81	struct net_device *dev = qdisc_dev(sch);
1da177e4 LT	82	struct teql_sched_data *q = qdisc_priv(sch);
1da177e4 LT	83
4cd8c9e8 KK	84	if (q->q.qlen < dev->tx_queue_len) {
4cd8c9e8 KK	85	__skb_queue_tail(&q->q, skb);
1da177e4 LT	86	sch->bstats.bytes += skb->len;
	87	sch->bstats.packets++;
	88	return 0;
	89	}
	90
1da177e4 LT	91	kfree_skb(skb);
	92	sch->qstats.drops++;
	93	return NET_XMIT_DROP;
	94	}
	95
	96	static int
	97	teql_requeue(struct sk_buff skb, struct Qdisc sch)
	98	{
	99	struct teql_sched_data *q = qdisc_priv(sch);
	100
	101	__skb_queue_head(&q->q, skb);
	102	sch->qstats.requeues++;
	103	return 0;
	104	}
	105
	106	static struct sk_buff *
	107	teql_dequeue(struct Qdisc* sch)
	108	{
	109	struct teql_sched_data *dat = qdisc_priv(sch);
b0e1e646	110	struct netdev_queue *dat_queue;
1da177e4 LT	111	struct sk_buff *skb;
	112
	113	skb = __skb_dequeue(&dat->q);
e8a0464c	114	dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
1da177e4	115	if (skb == NULL) {
b0e1e646	116	struct net_device *m = qdisc_dev(dat_queue->qdisc);
1da177e4 LT	117	if (m) {
	118	dat->m->slaves = sch;
	119	netif_wake_queue(m);
	120	}
	121	}
b0e1e646	122	sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen;
1da177e4 LT	123	return skb;
	124	}
	125
	126	static __inline__ void
	127	teql_neigh_release(struct neighbour *n)
	128	{
	129	if (n)
	130	neigh_release(n);
	131	}
	132
	133	static void
	134	teql_reset(struct Qdisc* sch)
	135	{
	136	struct teql_sched_data *dat = qdisc_priv(sch);
	137
	138	skb_queue_purge(&dat->q);
	139	sch->q.qlen = 0;
	140	teql_neigh_release(xchg(&dat->ncache, NULL));
	141	}
	142
	143	static void
	144	teql_destroy(struct Qdisc* sch)
	145	{
	146	struct Qdisc q, prev;
	147	struct teql_sched_data *dat = qdisc_priv(sch);
	148	struct teql_master *master = dat->m;
	149
	150	if ((prev = master->slaves) != NULL) {
	151	do {
	152	q = NEXT_SLAVE(prev);
	153	if (q == sch) {
	154	NEXT_SLAVE(prev) = NEXT_SLAVE(q);
	155	if (q == master->slaves) {
	156	master->slaves = NEXT_SLAVE(q);
	157	if (q == master->slaves) {
e8a0464c	158	struct netdev_queue *txq;
83874000	159	spinlock_t *root_lock;
e8a0464c DM	160
e8a0464c DM	161	txq = netdev_get_tx_queue(master->dev, 0);
1da177e4	162	master->slaves = NULL;
83874000 DM	163
	164	root_lock = qdisc_root_lock(txq->qdisc);
	165	spin_lock_bh(root_lock);
e8a0464c	166	qdisc_reset(txq->qdisc);
83874000	167	spin_unlock_bh(root_lock);
1da177e4 LT	168	}
	169	}
	170	skb_queue_purge(&dat->q);
	171	teql_neigh_release(xchg(&dat->ncache, NULL));
	172	break;
	173	}
10297b99	174
1da177e4 LT	175	} while ((prev = q) != master->slaves);
	176	}
	177	}
	178
1e90474c	179	static int teql_qdisc_init(struct Qdisc sch, struct nlattr opt)
1da177e4	180	{
5ce2d488	181	struct net_device *dev = qdisc_dev(sch);
1da177e4 LT	182	struct teql_master m = (struct teql_master)sch->ops;
	183	struct teql_sched_data *q = qdisc_priv(sch);
	184
	185	if (dev->hard_header_len > m->dev->hard_header_len)
	186	return -EINVAL;
	187
	188	if (m->dev == dev)
	189	return -ELOOP;
	190
	191	q->m = m;
	192
	193	skb_queue_head_init(&q->q);
	194
	195	if (m->slaves) {
	196	if (m->dev->flags & IFF_UP) {
	197	if ((m->dev->flags&IFF_POINTOPOINT && !(dev->flags&IFF_POINTOPOINT))
	198	\|\| (m->dev->flags&IFF_BROADCAST && !(dev->flags&IFF_BROADCAST))
	199	\|\| (m->dev->flags&IFF_MULTICAST && !(dev->flags&IFF_MULTICAST))
	200	\|\| dev->mtu < m->dev->mtu)
	201	return -EINVAL;
	202	} else {
	203	if (!(dev->flags&IFF_POINTOPOINT))
	204	m->dev->flags &= ~IFF_POINTOPOINT;
	205	if (!(dev->flags&IFF_BROADCAST))
	206	m->dev->flags &= ~IFF_BROADCAST;
	207	if (!(dev->flags&IFF_MULTICAST))
	208	m->dev->flags &= ~IFF_MULTICAST;
	209	if (dev->mtu < m->dev->mtu)
	210	m->dev->mtu = dev->mtu;
	211	}
	212	q->next = NEXT_SLAVE(m->slaves);
	213	NEXT_SLAVE(m->slaves) = sch;
	214	} else {
	215	q->next = sch;
	216	m->slaves = sch;
	217	m->dev->mtu = dev->mtu;
	218	m->dev->flags = (m->dev->flags&~FMASK)\|(dev->flags&FMASK);
	219	}
	220	return 0;
	221	}
	222
1da177e4 LT	223
	224	static int
	225	__teql_resolve(struct sk_buff skb, struct sk_buff skb_res, struct net_device *dev)
	226	{
e8a0464c DM	227	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
e8a0464c DM	228	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);
1da177e4 LT	229	struct neighbour *mn = skb->dst->neighbour;
	230	struct neighbour *n = q->ncache;
	231
	232	if (mn->tbl == NULL)
	233	return -EINVAL;
	234	if (n && n->tbl == mn->tbl &&
	235	memcmp(n->primary_key, mn->primary_key, mn->tbl->key_len) == 0) {
	236	atomic_inc(&n->refcnt);
	237	} else {
	238	n = __neigh_lookup_errno(mn->tbl, mn->primary_key, dev);
	239	if (IS_ERR(n))
	240	return PTR_ERR(n);
	241	}
	242	if (neigh_event_send(n, skb_res) == 0) {
	243	int err;
0c4e8581	244
1da177e4	245	read_lock(&n->lock);
0c4e8581 SH	246	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
0c4e8581 SH	247	n->ha, NULL, skb->len);
1da177e4	248	read_unlock(&n->lock);
0c4e8581	249
1da177e4 LT	250	if (err < 0) {
	251	neigh_release(n);
	252	return -EINVAL;
	253	}
	254	teql_neigh_release(xchg(&q->ncache, n));
	255	return 0;
	256	}
	257	neigh_release(n);
	258	return (skb_res == NULL) ? -EAGAIN : 1;
	259	}
	260
3b04ddde SH	261	static inline int teql_resolve(struct sk_buff *skb,
3b04ddde SH	262	struct sk_buff skb_res, struct net_device dev)
1da177e4	263	{
e8a0464c DM	264	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
e8a0464c DM	265	if (txq->qdisc == &noop_qdisc)
4f9f8311 EP	266	return -ENODEV;
4f9f8311 EP	267
3b04ddde	268	if (dev->header_ops == NULL \|\|
1da177e4 LT	269	skb->dst == NULL \|\|
	270	skb->dst->neighbour == NULL)
	271	return 0;
	272	return __teql_resolve(skb, skb_res, dev);
	273	}
	274
	275	static int teql_master_xmit(struct sk_buff skb, struct net_device dev)
	276	{
2941a486	277	struct teql_master *master = netdev_priv(dev);
1da177e4 LT	278	struct Qdisc start, q;
	279	int busy;
	280	int nores;
	281	int len = skb->len;
4e3ab47a	282	int subq = skb_get_queue_mapping(skb);
1da177e4 LT	283	struct sk_buff *skb_res = NULL;
	284
	285	start = master->slaves;
	286
	287	restart:
	288	nores = 0;
	289	busy = 0;
	290
	291	if ((q = start) == NULL)
	292	goto drop;
	293
	294	do {
5ce2d488	295	struct net_device *slave = qdisc_dev(q);
e8a0464c	296	struct netdev_queue *slave_txq;
10297b99	297
e8a0464c DM	298	slave_txq = netdev_get_tx_queue(slave, 0);
e8a0464c DM	299	if (slave_txq->qdisc_sleeping != q)
1da177e4	300	continue;
fd2ea0a7	301	if (__netif_subqueue_stopped(slave, subq) \|\|
f25f4e44	302	!netif_running(slave)) {
1da177e4 LT	303	busy = 1;
	304	continue;
	305	}
	306
	307	switch (teql_resolve(skb, skb_res, slave)) {
	308	case 0:
932ff279	309	if (netif_tx_trylock(slave)) {
fd2ea0a7	310	if (!__netif_subqueue_stopped(slave, subq) &&
1da177e4	311	slave->hard_start_xmit(skb, slave) == 0) {
932ff279	312	netif_tx_unlock(slave);
1da177e4 LT	313	master->slaves = NEXT_SLAVE(q);
	314	netif_wake_queue(dev);
	315	master->stats.tx_packets++;
	316	master->stats.tx_bytes += len;
	317	return 0;
	318	}
932ff279	319	netif_tx_unlock(slave);
1da177e4 LT	320	}
	321	if (netif_queue_stopped(dev))
	322	busy = 1;
	323	break;
	324	case 1:
	325	master->slaves = NEXT_SLAVE(q);
	326	return 0;
	327	default:
	328	nores = 1;
	329	break;
	330	}
bbe735e4	331	__skb_pull(skb, skb_network_offset(skb));
1da177e4 LT	332	} while ((q = NEXT_SLAVE(q)) != start);
	333
	334	if (nores && skb_res == NULL) {
	335	skb_res = skb;
	336	goto restart;
	337	}
	338
	339	if (busy) {
	340	netif_stop_queue(dev);
	341	return 1;
	342	}
	343	master->stats.tx_errors++;
	344
	345	drop:
	346	master->stats.tx_dropped++;
	347	dev_kfree_skb(skb);
	348	return 0;
	349	}
	350
	351	static int teql_master_open(struct net_device *dev)
	352	{
	353	struct Qdisc * q;
2941a486	354	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	355	int mtu = 0xFFFE;
	356	unsigned flags = IFF_NOARP\|IFF_MULTICAST;
	357
	358	if (m->slaves == NULL)
	359	return -EUNATCH;
	360
	361	flags = FMASK;
	362
	363	q = m->slaves;
	364	do {
5ce2d488	365	struct net_device *slave = qdisc_dev(q);
1da177e4 LT	366
	367	if (slave == NULL)
	368	return -EUNATCH;
	369
	370	if (slave->mtu < mtu)
	371	mtu = slave->mtu;
	372	if (slave->hard_header_len > LL_MAX_HEADER)
	373	return -EINVAL;
	374
	375	/* If all the slaves are BROADCAST, master is BROADCAST
	376	If all the slaves are PtP, master is PtP
	377	Otherwise, master is NBMA.
	378	*/
	379	if (!(slave->flags&IFF_POINTOPOINT))
	380	flags &= ~IFF_POINTOPOINT;
	381	if (!(slave->flags&IFF_BROADCAST))
	382	flags &= ~IFF_BROADCAST;
	383	if (!(slave->flags&IFF_MULTICAST))
	384	flags &= ~IFF_MULTICAST;
	385	} while ((q = NEXT_SLAVE(q)) != m->slaves);
	386
	387	m->dev->mtu = mtu;
	388	m->dev->flags = (m->dev->flags&~FMASK) \| flags;
	389	netif_start_queue(m->dev);
	390	return 0;
	391	}
	392
	393	static int teql_master_close(struct net_device *dev)
	394	{
	395	netif_stop_queue(dev);
	396	return 0;
	397	}
	398
	399	static struct net_device_stats teql_master_stats(struct net_device dev)
	400	{
2941a486	401	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	402	return &m->stats;
	403	}
	404
	405	static int teql_master_mtu(struct net_device *dev, int new_mtu)
	406	{
2941a486	407	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	408	struct Qdisc *q;
	409
	410	if (new_mtu < 68)
	411	return -EINVAL;
	412
	413	q = m->slaves;
	414	if (q) {
	415	do {
5ce2d488	416	if (new_mtu > qdisc_dev(q)->mtu)
1da177e4 LT	417	return -EINVAL;
	418	} while ((q=NEXT_SLAVE(q)) != m->slaves);
	419	}
	420
	421	dev->mtu = new_mtu;
	422	return 0;
	423	}
	424
	425	static __init void teql_master_setup(struct net_device *dev)
	426	{
2941a486	427	struct teql_master *master = netdev_priv(dev);
1da177e4 LT	428	struct Qdisc_ops *ops = &master->qops;
	429
	430	master->dev = dev;
	431	ops->priv_size = sizeof(struct teql_sched_data);
10297b99	432
1da177e4 LT	433	ops->enqueue = teql_enqueue;
	434	ops->dequeue = teql_dequeue;
	435	ops->requeue = teql_requeue;
	436	ops->init = teql_qdisc_init;
	437	ops->reset = teql_reset;
	438	ops->destroy = teql_destroy;
	439	ops->owner = THIS_MODULE;
	440
	441	dev->open = teql_master_open;
	442	dev->hard_start_xmit = teql_master_xmit;
	443	dev->stop = teql_master_close;
	444	dev->get_stats = teql_master_stats;
	445	dev->change_mtu = teql_master_mtu;
	446	dev->type = ARPHRD_VOID;
	447	dev->mtu = 1500;
	448	dev->tx_queue_len = 100;
	449	dev->flags = IFF_NOARP;
	450	dev->hard_header_len = LL_MAX_HEADER;
1da177e4 LT	451	}
	452
	453	static LIST_HEAD(master_dev_list);
	454	static int max_equalizers = 1;
	455	module_param(max_equalizers, int, 0);
	456	MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
	457
	458	static int __init teql_init(void)
	459	{
	460	int i;
	461	int err = -ENODEV;
	462
	463	for (i = 0; i < max_equalizers; i++) {
	464	struct net_device *dev;
	465	struct teql_master *master;
	466
	467	dev = alloc_netdev(sizeof(struct teql_master),
	468	"teql%d", teql_master_setup);
	469	if (!dev) {
	470	err = -ENOMEM;
	471	break;
	472	}
	473
	474	if ((err = register_netdev(dev))) {
	475	free_netdev(dev);
	476	break;
	477	}
	478
2941a486	479	master = netdev_priv(dev);
1da177e4 LT	480
	481	strlcpy(master->qops.id, dev->name, IFNAMSIZ);
	482	err = register_qdisc(&master->qops);
	483
	484	if (err) {
	485	unregister_netdev(dev);
	486	free_netdev(dev);
	487	break;
	488	}
	489
	490	list_add_tail(&master->master_list, &master_dev_list);
	491	}
	492	return i ? 0 : err;
	493	}
	494
10297b99	495	static void __exit teql_exit(void)
1da177e4 LT	496	{
	497	struct teql_master master, nxt;
	498
	499	list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
	500
	501	list_del(&master->master_list);
	502
	503	unregister_qdisc(&master->qops);
	504	unregister_netdev(master->dev);
	505	free_netdev(master->dev);
	506	}
	507	}
	508
	509	module_init(teql_init);
	510	module_exit(teql_exit);
	511
	512	MODULE_LICENSE("GPL");