[net-next-2.6.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(skb)->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(skb) == NULL ||
	    skb_dst(skb)->neighbour == NULL)
		return 0;
	return __teql_resolve(skb, skb_res, dev);
}

static netdev_tx_t 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) == NETDEV_TX_OK) {
					txq_trans_update(slave_txq);
					__netif_tx_unlock(slave_txq);
					master->slaves = NEXT_SLAVE(q);
					netif_wake_queue(dev);
					txq->tx_packets++;
					txq->tx_bytes += length;
					return NETDEV_TX_OK;
				}
				__netif_tx_unlock(slave_txq);
			}
			if (netif_queue_stopped(dev))
				busy = 1;
			break;
		case 1:
			master->slaves = NEXT_SLAVE(q);
			return NETDEV_TX_OK;
		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 NETDEV_TX_BUSY;
	}
	dev->stats.tx_errors++;

drop:
	txq->tx_dropped++;
	dev_kfree_skb(skb);
	return NETDEV_TX_OK;
}

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);
adf30907	225	struct neighbour *mn = skb_dst(skb)->neighbour;
1da177e4 LT	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 \|\|
adf30907 ED	265	skb_dst(skb) == NULL \|\|
adf30907 ED	266	skb_dst(skb)->neighbour == NULL)
1da177e4 LT	267	return 0;
	268	return __teql_resolve(skb, skb_res, dev);
	269	}
	270
6fef4c0c	271	static netdev_tx_t teql_master_xmit(struct sk_buff skb, struct net_device dev)
1da177e4	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) &&
6fef4c0c	310	slave_ops->ndo_start_xmit(skb, slave) == NETDEV_TX_OK) {
08baf561	311	txq_trans_update(slave_txq);
c3f26a26	312	__netif_tx_unlock(slave_txq);
1da177e4 LT	313	master->slaves = NEXT_SLAVE(q);
1da177e4 LT	314	netif_wake_queue(dev);
ab35cd4b ED	315	txq->tx_packets++;
ab35cd4b ED	316	txq->tx_bytes += length;
6ed10654	317	return NETDEV_TX_OK;
1da177e4	318	}
c3f26a26	319	__netif_tx_unlock(slave_txq);
1da177e4 LT	320	}
	321	if (netif_queue_stopped(dev))
	322	busy = 1;
	323	break;
	324	case 1:
	325	master->slaves = NEXT_SLAVE(q);
6ed10654	326	return NETDEV_TX_OK;
1da177e4 LT	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);
5b548140	341	return NETDEV_TX_BUSY;
1da177e4	342	}
ab35cd4b	343	dev->stats.tx_errors++;
1da177e4 LT	344
1da177e4 LT	345	drop:
ab35cd4b	346	txq->tx_dropped++;
1da177e4	347	dev_kfree_skb(skb);
6ed10654	348	return NETDEV_TX_OK;
1da177e4 LT	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
1da177e4 LT	399	static int teql_master_mtu(struct net_device *dev, int new_mtu)
1da177e4 LT	400	{
2941a486	401	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	402	struct Qdisc *q;
	403
	404	if (new_mtu < 68)
	405	return -EINVAL;
	406
	407	q = m->slaves;
	408	if (q) {
	409	do {
5ce2d488	410	if (new_mtu > qdisc_dev(q)->mtu)
1da177e4 LT	411	return -EINVAL;
	412	} while ((q=NEXT_SLAVE(q)) != m->slaves);
	413	}
	414
	415	dev->mtu = new_mtu;
	416	return 0;
	417	}
	418
61294e2e SH	419	static const struct net_device_ops teql_netdev_ops = {
	420	.ndo_open = teql_master_open,
	421	.ndo_stop = teql_master_close,
	422	.ndo_start_xmit = teql_master_xmit,
61294e2e SH	423	.ndo_change_mtu = teql_master_mtu,
	424	};
	425
1da177e4 LT	426	static __init void teql_master_setup(struct net_device *dev)
1da177e4 LT	427	{
2941a486	428	struct teql_master *master = netdev_priv(dev);
1da177e4 LT	429	struct Qdisc_ops *ops = &master->qops;
	430
	431	master->dev = dev;
	432	ops->priv_size = sizeof(struct teql_sched_data);
10297b99	433
1da177e4 LT	434	ops->enqueue = teql_enqueue;
1da177e4 LT	435	ops->dequeue = teql_dequeue;
8e3af978	436	ops->peek = teql_peek;
1da177e4 LT	437	ops->init = teql_qdisc_init;
	438	ops->reset = teql_reset;
	439	ops->destroy = teql_destroy;
	440	ops->owner = THIS_MODULE;
	441
61294e2e	442	dev->netdev_ops = &teql_netdev_ops;
1da177e4 LT	443	dev->type = ARPHRD_VOID;
	444	dev->mtu = 1500;
	445	dev->tx_queue_len = 100;
	446	dev->flags = IFF_NOARP;
	447	dev->hard_header_len = LL_MAX_HEADER;
1da177e4 LT	448	}
	449
	450	static LIST_HEAD(master_dev_list);
	451	static int max_equalizers = 1;
	452	module_param(max_equalizers, int, 0);
	453	MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
	454
	455	static int __init teql_init(void)
	456	{
	457	int i;
	458	int err = -ENODEV;
	459
	460	for (i = 0; i < max_equalizers; i++) {
	461	struct net_device *dev;
	462	struct teql_master *master;
	463
	464	dev = alloc_netdev(sizeof(struct teql_master),
	465	"teql%d", teql_master_setup);
	466	if (!dev) {
	467	err = -ENOMEM;
	468	break;
	469	}
	470
	471	if ((err = register_netdev(dev))) {
	472	free_netdev(dev);
	473	break;
	474	}
	475
2941a486	476	master = netdev_priv(dev);
1da177e4 LT	477
	478	strlcpy(master->qops.id, dev->name, IFNAMSIZ);
	479	err = register_qdisc(&master->qops);
	480
	481	if (err) {
	482	unregister_netdev(dev);
	483	free_netdev(dev);
	484	break;
	485	}
	486
	487	list_add_tail(&master->master_list, &master_dev_list);
	488	}
	489	return i ? 0 : err;
	490	}
	491
10297b99	492	static void __exit teql_exit(void)
1da177e4 LT	493	{
	494	struct teql_master master, nxt;
	495
	496	list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
	497
	498	list_del(&master->master_list);
	499
	500	unregister_qdisc(&master->qops);
	501	unregister_netdev(master->dev);
	502	free_netdev(master->dev);
	503	}
	504	}
	505
	506	module_init(teql_init);
	507	module_exit(teql_exit);
	508
	509	MODULE_LICENSE("GPL");