[deliverable/linux.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 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 += qdisc_pkt_len(skb);
		sch->bstats.packets++;
		return 0;
	}

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

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 struct sk_buff *
teql_peek(struct Qdisc* sch)
{
	/* teql is meant to be used as root qdisc */
	return NULL;
}

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_sleeping_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 netdev_queue *txq = netdev_get_tx_queue(dev, 0);
	struct Qdisc *start, *q;
	int busy;
	int nores;
	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 = netdev_get_tx_queue(slave, 0);
		const struct net_device_ops *slave_ops = slave->netdev_ops;

		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_txq)) {
				unsigned int length = qdisc_pkt_len(skb);

				if (!netif_tx_queue_stopped(slave_txq) &&
				    !netif_tx_queue_frozen(slave_txq) &&
				    slave_ops->ndo_start_xmit(skb, slave) == 0) {
					__netif_tx_unlock(slave_txq);
					master->slaves = NEXT_SLAVE(q);
					netif_wake_queue(dev);
					txq->tx_packets++;
					txq->tx_bytes += length;
					return 0;
				}
				__netif_tx_unlock(slave_txq);
			}
			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;
	}
	dev->stats.tx_errors++;

drop:
	txq->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 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 const struct net_device_ops teql_netdev_ops = {
	.ndo_open	= teql_master_open,
	.ndo_stop	= teql_master_close,
	.ndo_start_xmit	= teql_master_xmit,
	.ndo_change_mtu	= teql_master_mtu,
};

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->peek	=	teql_peek;
	ops->init	=	teql_qdisc_init;
	ops->reset	=	teql_reset;
	ops->destroy	=	teql_destroy;
	ops->owner	=	THIS_MODULE;

	dev->netdev_ops =       &teql_netdev_ops;
	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;
1da177e4 LT	61	};
	62
	63	struct teql_sched_data
	64	{
	65	struct Qdisc *next;
	66	struct teql_master *m;
	67	struct neighbour *ncache;
	68	struct sk_buff_head q;
	69	};
	70
	71	#define NEXT_SLAVE(q) (((struct teql_sched_data*)qdisc_priv(q))->next)
	72
cc8fd14d	73	#define FMASK (IFF_BROADCAST\|IFF_POINTOPOINT)
1da177e4 LT	74
	75	/* "teql" qdisc routines /
	76
	77	static int
	78	teql_enqueue(struct sk_buff skb, struct Qdisc sch)
	79	{
5ce2d488	80	struct net_device *dev = qdisc_dev(sch);
1da177e4 LT	81	struct teql_sched_data *q = qdisc_priv(sch);
1da177e4 LT	82
4cd8c9e8 KK	83	if (q->q.qlen < dev->tx_queue_len) {
4cd8c9e8 KK	84	__skb_queue_tail(&q->q, skb);
0abf77e5	85	sch->bstats.bytes += qdisc_pkt_len(skb);
1da177e4 LT	86	sch->bstats.packets++;
	87	return 0;
	88	}
	89
1da177e4 LT	90	kfree_skb(skb);
	91	sch->qstats.drops++;
	92	return NET_XMIT_DROP;
	93	}
	94
1da177e4 LT	95	static struct sk_buff *
	96	teql_dequeue(struct Qdisc* sch)
	97	{
	98	struct teql_sched_data *dat = qdisc_priv(sch);
b0e1e646	99	struct netdev_queue *dat_queue;
1da177e4 LT	100	struct sk_buff *skb;
	101
	102	skb = __skb_dequeue(&dat->q);
e8a0464c	103	dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
1da177e4	104	if (skb == NULL) {
b0e1e646	105	struct net_device *m = qdisc_dev(dat_queue->qdisc);
1da177e4 LT	106	if (m) {
	107	dat->m->slaves = sch;
	108	netif_wake_queue(m);
	109	}
	110	}
b0e1e646	111	sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen;
1da177e4 LT	112	return skb;
	113	}
	114
8e3af978 JP	115	static struct sk_buff *
	116	teql_peek(struct Qdisc* sch)
	117	{
	118	/* teql is meant to be used as root qdisc */
	119	return NULL;
	120	}
	121
1da177e4 LT	122	static __inline__ void
	123	teql_neigh_release(struct neighbour *n)
	124	{
	125	if (n)
	126	neigh_release(n);
	127	}
	128
	129	static void
	130	teql_reset(struct Qdisc* sch)
	131	{
	132	struct teql_sched_data *dat = qdisc_priv(sch);
	133
	134	skb_queue_purge(&dat->q);
	135	sch->q.qlen = 0;
	136	teql_neigh_release(xchg(&dat->ncache, NULL));
	137	}
	138
	139	static void
	140	teql_destroy(struct Qdisc* sch)
	141	{
	142	struct Qdisc q, prev;
	143	struct teql_sched_data *dat = qdisc_priv(sch);
	144	struct teql_master *master = dat->m;
	145
	146	if ((prev = master->slaves) != NULL) {
	147	do {
	148	q = NEXT_SLAVE(prev);
	149	if (q == sch) {
	150	NEXT_SLAVE(prev) = NEXT_SLAVE(q);
	151	if (q == master->slaves) {
	152	master->slaves = NEXT_SLAVE(q);
	153	if (q == master->slaves) {
e8a0464c	154	struct netdev_queue *txq;
83874000	155	spinlock_t *root_lock;
e8a0464c DM	156
e8a0464c DM	157	txq = netdev_get_tx_queue(master->dev, 0);
1da177e4	158	master->slaves = NULL;
83874000	159
102396ae	160	root_lock = qdisc_root_sleeping_lock(txq->qdisc);
83874000	161	spin_lock_bh(root_lock);
e8a0464c	162	qdisc_reset(txq->qdisc);
83874000	163	spin_unlock_bh(root_lock);
1da177e4 LT	164	}
	165	}
	166	skb_queue_purge(&dat->q);
	167	teql_neigh_release(xchg(&dat->ncache, NULL));
	168	break;
	169	}
10297b99	170
1da177e4 LT	171	} while ((prev = q) != master->slaves);
	172	}
	173	}
	174
1e90474c	175	static int teql_qdisc_init(struct Qdisc sch, struct nlattr opt)
1da177e4	176	{
5ce2d488	177	struct net_device *dev = qdisc_dev(sch);
1da177e4 LT	178	struct teql_master m = (struct teql_master)sch->ops;
	179	struct teql_sched_data *q = qdisc_priv(sch);
	180
	181	if (dev->hard_header_len > m->dev->hard_header_len)
	182	return -EINVAL;
	183
	184	if (m->dev == dev)
	185	return -ELOOP;
	186
	187	q->m = m;
	188
	189	skb_queue_head_init(&q->q);
	190
	191	if (m->slaves) {
	192	if (m->dev->flags & IFF_UP) {
	193	if ((m->dev->flags&IFF_POINTOPOINT && !(dev->flags&IFF_POINTOPOINT))
	194	\|\| (m->dev->flags&IFF_BROADCAST && !(dev->flags&IFF_BROADCAST))
	195	\|\| (m->dev->flags&IFF_MULTICAST && !(dev->flags&IFF_MULTICAST))
	196	\|\| dev->mtu < m->dev->mtu)
	197	return -EINVAL;
	198	} else {
	199	if (!(dev->flags&IFF_POINTOPOINT))
	200	m->dev->flags &= ~IFF_POINTOPOINT;
	201	if (!(dev->flags&IFF_BROADCAST))
	202	m->dev->flags &= ~IFF_BROADCAST;
	203	if (!(dev->flags&IFF_MULTICAST))
	204	m->dev->flags &= ~IFF_MULTICAST;
	205	if (dev->mtu < m->dev->mtu)
	206	m->dev->mtu = dev->mtu;
	207	}
	208	q->next = NEXT_SLAVE(m->slaves);
	209	NEXT_SLAVE(m->slaves) = sch;
	210	} else {
	211	q->next = sch;
	212	m->slaves = sch;
	213	m->dev->mtu = dev->mtu;
	214	m->dev->flags = (m->dev->flags&~FMASK)\|(dev->flags&FMASK);
	215	}
	216	return 0;
	217	}
	218
1da177e4 LT	219
	220	static int
	221	__teql_resolve(struct sk_buff skb, struct sk_buff skb_res, struct net_device *dev)
	222	{
e8a0464c DM	223	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
e8a0464c DM	224	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);
1da177e4 LT	225	struct neighbour *mn = skb->dst->neighbour;
	226	struct neighbour *n = q->ncache;
	227
	228	if (mn->tbl == NULL)
	229	return -EINVAL;
	230	if (n && n->tbl == mn->tbl &&
	231	memcmp(n->primary_key, mn->primary_key, mn->tbl->key_len) == 0) {
	232	atomic_inc(&n->refcnt);
	233	} else {
	234	n = __neigh_lookup_errno(mn->tbl, mn->primary_key, dev);
	235	if (IS_ERR(n))
	236	return PTR_ERR(n);
	237	}
	238	if (neigh_event_send(n, skb_res) == 0) {
	239	int err;
0c4e8581	240
1da177e4	241	read_lock(&n->lock);
0c4e8581 SH	242	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
0c4e8581 SH	243	n->ha, NULL, skb->len);
1da177e4	244	read_unlock(&n->lock);
0c4e8581	245
1da177e4 LT	246	if (err < 0) {
	247	neigh_release(n);
	248	return -EINVAL;
	249	}
	250	teql_neigh_release(xchg(&q->ncache, n));
	251	return 0;
	252	}
	253	neigh_release(n);
	254	return (skb_res == NULL) ? -EAGAIN : 1;
	255	}
	256
3b04ddde SH	257	static inline int teql_resolve(struct sk_buff *skb,
3b04ddde SH	258	struct sk_buff skb_res, struct net_device dev)
1da177e4	259	{
e8a0464c DM	260	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
e8a0464c DM	261	if (txq->qdisc == &noop_qdisc)
4f9f8311 EP	262	return -ENODEV;
4f9f8311 EP	263
3b04ddde	264	if (dev->header_ops == NULL \|\|
1da177e4 LT	265	skb->dst == NULL \|\|
	266	skb->dst->neighbour == NULL)
	267	return 0;
	268	return __teql_resolve(skb, skb_res, dev);
	269	}
	270
	271	static int teql_master_xmit(struct sk_buff skb, struct net_device dev)
	272	{
2941a486	273	struct teql_master *master = netdev_priv(dev);
ab35cd4b	274	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
1da177e4 LT	275	struct Qdisc start, q;
	276	int busy;
	277	int nores;
4e3ab47a	278	int subq = skb_get_queue_mapping(skb);
1da177e4 LT	279	struct sk_buff *skb_res = NULL;
	280
	281	start = master->slaves;
	282
	283	restart:
	284	nores = 0;
	285	busy = 0;
	286
	287	if ((q = start) == NULL)
	288	goto drop;
	289
	290	do {
5ce2d488	291	struct net_device *slave = qdisc_dev(q);
61294e2e SH	292	struct netdev_queue *slave_txq = netdev_get_tx_queue(slave, 0);
61294e2e SH	293	const struct net_device_ops *slave_ops = slave->netdev_ops;
10297b99	294
e8a0464c	295	if (slave_txq->qdisc_sleeping != q)
1da177e4	296	continue;
fd2ea0a7	297	if (__netif_subqueue_stopped(slave, subq) \|\|
f25f4e44	298	!netif_running(slave)) {
1da177e4 LT	299	busy = 1;
	300	continue;
	301	}
	302
	303	switch (teql_resolve(skb, skb_res, slave)) {
	304	case 0:
c3f26a26	305	if (__netif_tx_trylock(slave_txq)) {
c0f84d0d ED	306	unsigned int length = qdisc_pkt_len(skb);
c0f84d0d ED	307
c3f26a26 DM	308	if (!netif_tx_queue_stopped(slave_txq) &&
c3f26a26 DM	309	!netif_tx_queue_frozen(slave_txq) &&
61294e2e	310	slave_ops->ndo_start_xmit(skb, slave) == 0) {
c3f26a26	311	__netif_tx_unlock(slave_txq);
1da177e4 LT	312	master->slaves = NEXT_SLAVE(q);
1da177e4 LT	313	netif_wake_queue(dev);
ab35cd4b ED	314	txq->tx_packets++;
ab35cd4b ED	315	txq->tx_bytes += length;
1da177e4 LT	316	return 0;
1da177e4 LT	317	}
c3f26a26	318	__netif_tx_unlock(slave_txq);
1da177e4 LT	319	}
	320	if (netif_queue_stopped(dev))
	321	busy = 1;
	322	break;
	323	case 1:
	324	master->slaves = NEXT_SLAVE(q);
	325	return 0;
	326	default:
	327	nores = 1;
	328	break;
	329	}
bbe735e4	330	__skb_pull(skb, skb_network_offset(skb));
1da177e4 LT	331	} while ((q = NEXT_SLAVE(q)) != start);
	332
	333	if (nores && skb_res == NULL) {
	334	skb_res = skb;
	335	goto restart;
	336	}
	337
	338	if (busy) {
	339	netif_stop_queue(dev);
	340	return 1;
	341	}
ab35cd4b	342	dev->stats.tx_errors++;
1da177e4 LT	343
1da177e4 LT	344	drop:
ab35cd4b	345	txq->tx_dropped++;
1da177e4 LT	346	dev_kfree_skb(skb);
	347	return 0;
	348	}
	349
	350	static int teql_master_open(struct net_device *dev)
	351	{
	352	struct Qdisc * q;
2941a486	353	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	354	int mtu = 0xFFFE;
	355	unsigned flags = IFF_NOARP\|IFF_MULTICAST;
	356
	357	if (m->slaves == NULL)
	358	return -EUNATCH;
	359
	360	flags = FMASK;
	361
	362	q = m->slaves;
	363	do {
5ce2d488	364	struct net_device *slave = qdisc_dev(q);
1da177e4 LT	365
	366	if (slave == NULL)
	367	return -EUNATCH;
	368
	369	if (slave->mtu < mtu)
	370	mtu = slave->mtu;
	371	if (slave->hard_header_len > LL_MAX_HEADER)
	372	return -EINVAL;
	373
	374	/* If all the slaves are BROADCAST, master is BROADCAST
	375	If all the slaves are PtP, master is PtP
	376	Otherwise, master is NBMA.
	377	*/
	378	if (!(slave->flags&IFF_POINTOPOINT))
	379	flags &= ~IFF_POINTOPOINT;
	380	if (!(slave->flags&IFF_BROADCAST))
	381	flags &= ~IFF_BROADCAST;
	382	if (!(slave->flags&IFF_MULTICAST))
	383	flags &= ~IFF_MULTICAST;
	384	} while ((q = NEXT_SLAVE(q)) != m->slaves);
	385
	386	m->dev->mtu = mtu;
	387	m->dev->flags = (m->dev->flags&~FMASK) \| flags;
	388	netif_start_queue(m->dev);
	389	return 0;
	390	}
	391
	392	static int teql_master_close(struct net_device *dev)
	393	{
	394	netif_stop_queue(dev);
	395	return 0;
	396	}
	397
1da177e4 LT	398	static int teql_master_mtu(struct net_device *dev, int new_mtu)
1da177e4 LT	399	{
2941a486	400	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	401	struct Qdisc *q;
	402
	403	if (new_mtu < 68)
	404	return -EINVAL;
	405
	406	q = m->slaves;
	407	if (q) {
	408	do {
5ce2d488	409	if (new_mtu > qdisc_dev(q)->mtu)
1da177e4 LT	410	return -EINVAL;
	411	} while ((q=NEXT_SLAVE(q)) != m->slaves);
	412	}
	413
	414	dev->mtu = new_mtu;
	415	return 0;
	416	}
	417
61294e2e SH	418	static const struct net_device_ops teql_netdev_ops = {
	419	.ndo_open = teql_master_open,
	420	.ndo_stop = teql_master_close,
	421	.ndo_start_xmit = teql_master_xmit,
61294e2e SH	422	.ndo_change_mtu = teql_master_mtu,
	423	};
	424
1da177e4 LT	425	static __init void teql_master_setup(struct net_device *dev)
1da177e4 LT	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;
1da177e4 LT	434	ops->dequeue = teql_dequeue;
8e3af978	435	ops->peek = teql_peek;
1da177e4 LT	436	ops->init = teql_qdisc_init;
	437	ops->reset = teql_reset;
	438	ops->destroy = teql_destroy;
	439	ops->owner = THIS_MODULE;
	440
61294e2e	441	dev->netdev_ops = &teql_netdev_ops;
1da177e4 LT	442	dev->type = ARPHRD_VOID;
	443	dev->mtu = 1500;
	444	dev->tx_queue_len = 100;
	445	dev->flags = IFF_NOARP;
	446	dev->hard_header_len = LL_MAX_HEADER;
1da177e4 LT	447	}
	448
	449	static LIST_HEAD(master_dev_list);
	450	static int max_equalizers = 1;
	451	module_param(max_equalizers, int, 0);
	452	MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
	453
	454	static int __init teql_init(void)
	455	{
	456	int i;
	457	int err = -ENODEV;
	458
	459	for (i = 0; i < max_equalizers; i++) {
	460	struct net_device *dev;
	461	struct teql_master *master;
	462
	463	dev = alloc_netdev(sizeof(struct teql_master),
	464	"teql%d", teql_master_setup);
	465	if (!dev) {
	466	err = -ENOMEM;
	467	break;
	468	}
	469
	470	if ((err = register_netdev(dev))) {
	471	free_netdev(dev);
	472	break;
	473	}
	474
2941a486	475	master = netdev_priv(dev);
1da177e4 LT	476
	477	strlcpy(master->qops.id, dev->name, IFNAMSIZ);
	478	err = register_qdisc(&master->qops);
	479
	480	if (err) {
	481	unregister_netdev(dev);
	482	free_netdev(dev);
	483	break;
	484	}
	485
	486	list_add_tail(&master->master_list, &master_dev_list);
	487	}
	488	return i ? 0 : err;
	489	}
	490
10297b99	491	static void __exit teql_exit(void)
1da177e4 LT	492	{
	493	struct teql_master master, nxt;
	494
	495	list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
	496
	497	list_del(&master->master_list);
	498
	499	unregister_qdisc(&master->qops);
	500	unregister_netdev(master->dev);
	501	free_netdev(master->dev);
	502	}
	503	}
	504
	505	module_init(teql_init);
	506	module_exit(teql_exit);
	507
	508	MODULE_LICENSE("GPL");