[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 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 += 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 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;

		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_txq)) {
				if (!netif_tx_queue_stopped(slave_txq) &&
				    !netif_tx_queue_frozen(slave_txq) &&
				    slave->hard_start_xmit(skb, slave) == 0) {
					__netif_tx_unlock(slave_txq);
					master->slaves = NEXT_SLAVE(q);
					netif_wake_queue(dev);
					master->stats.tx_packets++;
					master->stats.tx_bytes +=
						qdisc_pkt_len(skb);
					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;
	}
	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->peek	=	teql_peek;
	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);
0abf77e5	86	sch->bstats.bytes += qdisc_pkt_len(skb);
1da177e4 LT	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
1da177e4 LT	96	static struct sk_buff *
	97	teql_dequeue(struct Qdisc* sch)
	98	{
	99	struct teql_sched_data *dat = qdisc_priv(sch);
b0e1e646	100	struct netdev_queue *dat_queue;
1da177e4 LT	101	struct sk_buff *skb;
	102
	103	skb = __skb_dequeue(&dat->q);
e8a0464c	104	dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
1da177e4	105	if (skb == NULL) {
b0e1e646	106	struct net_device *m = qdisc_dev(dat_queue->qdisc);
1da177e4 LT	107	if (m) {
	108	dat->m->slaves = sch;
	109	netif_wake_queue(m);
	110	}
	111	}
b0e1e646	112	sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen;
1da177e4 LT	113	return skb;
	114	}
	115
8e3af978 JP	116	static struct sk_buff *
	117	teql_peek(struct Qdisc* sch)
	118	{
	119	/* teql is meant to be used as root qdisc */
	120	return NULL;
	121	}
	122
1da177e4 LT	123	static __inline__ void
	124	teql_neigh_release(struct neighbour *n)
	125	{
	126	if (n)
	127	neigh_release(n);
	128	}
	129
	130	static void
	131	teql_reset(struct Qdisc* sch)
	132	{
	133	struct teql_sched_data *dat = qdisc_priv(sch);
	134
	135	skb_queue_purge(&dat->q);
	136	sch->q.qlen = 0;
	137	teql_neigh_release(xchg(&dat->ncache, NULL));
	138	}
	139
	140	static void
	141	teql_destroy(struct Qdisc* sch)
	142	{
	143	struct Qdisc q, prev;
	144	struct teql_sched_data *dat = qdisc_priv(sch);
	145	struct teql_master *master = dat->m;
	146
	147	if ((prev = master->slaves) != NULL) {
	148	do {
	149	q = NEXT_SLAVE(prev);
	150	if (q == sch) {
	151	NEXT_SLAVE(prev) = NEXT_SLAVE(q);
	152	if (q == master->slaves) {
	153	master->slaves = NEXT_SLAVE(q);
	154	if (q == master->slaves) {
e8a0464c	155	struct netdev_queue *txq;
83874000	156	spinlock_t *root_lock;
e8a0464c DM	157
e8a0464c DM	158	txq = netdev_get_tx_queue(master->dev, 0);
1da177e4	159	master->slaves = NULL;
83874000	160
102396ae	161	root_lock = qdisc_root_sleeping_lock(txq->qdisc);
83874000	162	spin_lock_bh(root_lock);
e8a0464c	163	qdisc_reset(txq->qdisc);
83874000	164	spin_unlock_bh(root_lock);
1da177e4 LT	165	}
	166	}
	167	skb_queue_purge(&dat->q);
	168	teql_neigh_release(xchg(&dat->ncache, NULL));
	169	break;
	170	}
10297b99	171
1da177e4 LT	172	} while ((prev = q) != master->slaves);
	173	}
	174	}
	175
1e90474c	176	static int teql_qdisc_init(struct Qdisc sch, struct nlattr opt)
1da177e4	177	{
5ce2d488	178	struct net_device *dev = qdisc_dev(sch);
1da177e4 LT	179	struct teql_master m = (struct teql_master)sch->ops;
	180	struct teql_sched_data *q = qdisc_priv(sch);
	181
	182	if (dev->hard_header_len > m->dev->hard_header_len)
	183	return -EINVAL;
	184
	185	if (m->dev == dev)
	186	return -ELOOP;
	187
	188	q->m = m;
	189
	190	skb_queue_head_init(&q->q);
	191
	192	if (m->slaves) {
	193	if (m->dev->flags & IFF_UP) {
	194	if ((m->dev->flags&IFF_POINTOPOINT && !(dev->flags&IFF_POINTOPOINT))
	195	\|\| (m->dev->flags&IFF_BROADCAST && !(dev->flags&IFF_BROADCAST))
	196	\|\| (m->dev->flags&IFF_MULTICAST && !(dev->flags&IFF_MULTICAST))
	197	\|\| dev->mtu < m->dev->mtu)
	198	return -EINVAL;
	199	} else {
	200	if (!(dev->flags&IFF_POINTOPOINT))
	201	m->dev->flags &= ~IFF_POINTOPOINT;
	202	if (!(dev->flags&IFF_BROADCAST))
	203	m->dev->flags &= ~IFF_BROADCAST;
	204	if (!(dev->flags&IFF_MULTICAST))
	205	m->dev->flags &= ~IFF_MULTICAST;
	206	if (dev->mtu < m->dev->mtu)
	207	m->dev->mtu = dev->mtu;
	208	}
	209	q->next = NEXT_SLAVE(m->slaves);
	210	NEXT_SLAVE(m->slaves) = sch;
	211	} else {
	212	q->next = sch;
	213	m->slaves = sch;
	214	m->dev->mtu = dev->mtu;
	215	m->dev->flags = (m->dev->flags&~FMASK)\|(dev->flags&FMASK);
	216	}
	217	return 0;
	218	}
	219
1da177e4 LT	220
	221	static int
	222	__teql_resolve(struct sk_buff skb, struct sk_buff skb_res, struct net_device *dev)
	223	{
e8a0464c DM	224	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
e8a0464c DM	225	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);
1da177e4 LT	226	struct neighbour *mn = skb->dst->neighbour;
	227	struct neighbour *n = q->ncache;
	228
	229	if (mn->tbl == NULL)
	230	return -EINVAL;
	231	if (n && n->tbl == mn->tbl &&
	232	memcmp(n->primary_key, mn->primary_key, mn->tbl->key_len) == 0) {
	233	atomic_inc(&n->refcnt);
	234	} else {
	235	n = __neigh_lookup_errno(mn->tbl, mn->primary_key, dev);
	236	if (IS_ERR(n))
	237	return PTR_ERR(n);
	238	}
	239	if (neigh_event_send(n, skb_res) == 0) {
	240	int err;
0c4e8581	241
1da177e4	242	read_lock(&n->lock);
0c4e8581 SH	243	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
0c4e8581 SH	244	n->ha, NULL, skb->len);
1da177e4	245	read_unlock(&n->lock);
0c4e8581	246
1da177e4 LT	247	if (err < 0) {
	248	neigh_release(n);
	249	return -EINVAL;
	250	}
	251	teql_neigh_release(xchg(&q->ncache, n));
	252	return 0;
	253	}
	254	neigh_release(n);
	255	return (skb_res == NULL) ? -EAGAIN : 1;
	256	}
	257
3b04ddde SH	258	static inline int teql_resolve(struct sk_buff *skb,
3b04ddde SH	259	struct sk_buff skb_res, struct net_device dev)
1da177e4	260	{
e8a0464c DM	261	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
e8a0464c DM	262	if (txq->qdisc == &noop_qdisc)
4f9f8311 EP	263	return -ENODEV;
4f9f8311 EP	264
3b04ddde	265	if (dev->header_ops == NULL \|\|
1da177e4 LT	266	skb->dst == NULL \|\|
	267	skb->dst->neighbour == NULL)
	268	return 0;
	269	return __teql_resolve(skb, skb_res, dev);
	270	}
	271
	272	static int teql_master_xmit(struct sk_buff skb, struct net_device dev)
	273	{
2941a486	274	struct teql_master *master = netdev_priv(dev);
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);
e8a0464c	292	struct netdev_queue *slave_txq;
10297b99	293
e8a0464c DM	294	slave_txq = netdev_get_tx_queue(slave, 0);
e8a0464c DM	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 DM	305	if (__netif_tx_trylock(slave_txq)) {
	306	if (!netif_tx_queue_stopped(slave_txq) &&
	307	!netif_tx_queue_frozen(slave_txq) &&
1da177e4	308	slave->hard_start_xmit(skb, slave) == 0) {
c3f26a26	309	__netif_tx_unlock(slave_txq);
1da177e4 LT	310	master->slaves = NEXT_SLAVE(q);
	311	netif_wake_queue(dev);
	312	master->stats.tx_packets++;
0abf77e5 JK	313	master->stats.tx_bytes +=
0abf77e5 JK	314	qdisc_pkt_len(skb);
1da177e4 LT	315	return 0;
1da177e4 LT	316	}
c3f26a26	317	__netif_tx_unlock(slave_txq);
1da177e4 LT	318	}
	319	if (netif_queue_stopped(dev))
	320	busy = 1;
	321	break;
	322	case 1:
	323	master->slaves = NEXT_SLAVE(q);
	324	return 0;
	325	default:
	326	nores = 1;
	327	break;
	328	}
bbe735e4	329	__skb_pull(skb, skb_network_offset(skb));
1da177e4 LT	330	} while ((q = NEXT_SLAVE(q)) != start);
	331
	332	if (nores && skb_res == NULL) {
	333	skb_res = skb;
	334	goto restart;
	335	}
	336
	337	if (busy) {
	338	netif_stop_queue(dev);
	339	return 1;
	340	}
	341	master->stats.tx_errors++;
	342
	343	drop:
	344	master->stats.tx_dropped++;
	345	dev_kfree_skb(skb);
	346	return 0;
	347	}
	348
	349	static int teql_master_open(struct net_device *dev)
	350	{
	351	struct Qdisc * q;
2941a486	352	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	353	int mtu = 0xFFFE;
	354	unsigned flags = IFF_NOARP\|IFF_MULTICAST;
	355
	356	if (m->slaves == NULL)
	357	return -EUNATCH;
	358
	359	flags = FMASK;
	360
	361	q = m->slaves;
	362	do {
5ce2d488	363	struct net_device *slave = qdisc_dev(q);
1da177e4 LT	364
	365	if (slave == NULL)
	366	return -EUNATCH;
	367
	368	if (slave->mtu < mtu)
	369	mtu = slave->mtu;
	370	if (slave->hard_header_len > LL_MAX_HEADER)
	371	return -EINVAL;
	372
	373	/* If all the slaves are BROADCAST, master is BROADCAST
	374	If all the slaves are PtP, master is PtP
	375	Otherwise, master is NBMA.
	376	*/
	377	if (!(slave->flags&IFF_POINTOPOINT))
	378	flags &= ~IFF_POINTOPOINT;
	379	if (!(slave->flags&IFF_BROADCAST))
	380	flags &= ~IFF_BROADCAST;
	381	if (!(slave->flags&IFF_MULTICAST))
	382	flags &= ~IFF_MULTICAST;
	383	} while ((q = NEXT_SLAVE(q)) != m->slaves);
	384
	385	m->dev->mtu = mtu;
	386	m->dev->flags = (m->dev->flags&~FMASK) \| flags;
	387	netif_start_queue(m->dev);
	388	return 0;
	389	}
	390
	391	static int teql_master_close(struct net_device *dev)
	392	{
	393	netif_stop_queue(dev);
	394	return 0;
	395	}
	396
	397	static struct net_device_stats teql_master_stats(struct net_device dev)
	398	{
2941a486	399	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	400	return &m->stats;
	401	}
	402
	403	static int teql_master_mtu(struct net_device *dev, int new_mtu)
	404	{
2941a486	405	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	406	struct Qdisc *q;
	407
	408	if (new_mtu < 68)
	409	return -EINVAL;
	410
	411	q = m->slaves;
	412	if (q) {
	413	do {
5ce2d488	414	if (new_mtu > qdisc_dev(q)->mtu)
1da177e4 LT	415	return -EINVAL;
	416	} while ((q=NEXT_SLAVE(q)) != m->slaves);
	417	}
	418
	419	dev->mtu = new_mtu;
	420	return 0;
	421	}
	422
	423	static __init void teql_master_setup(struct net_device *dev)
	424	{
2941a486	425	struct teql_master *master = netdev_priv(dev);
1da177e4 LT	426	struct Qdisc_ops *ops = &master->qops;
	427
	428	master->dev = dev;
	429	ops->priv_size = sizeof(struct teql_sched_data);
10297b99	430
1da177e4 LT	431	ops->enqueue = teql_enqueue;
1da177e4 LT	432	ops->dequeue = teql_dequeue;
8e3af978	433	ops->peek = teql_peek;
1da177e4 LT	434	ops->init = teql_qdisc_init;
	435	ops->reset = teql_reset;
	436	ops->destroy = teql_destroy;
	437	ops->owner = THIS_MODULE;
	438
	439	dev->open = teql_master_open;
	440	dev->hard_start_xmit = teql_master_xmit;
	441	dev->stop = teql_master_close;
	442	dev->get_stats = teql_master_stats;
	443	dev->change_mtu = teql_master_mtu;
	444	dev->type = ARPHRD_VOID;
	445	dev->mtu = 1500;
	446	dev->tx_queue_len = 100;
	447	dev->flags = IFF_NOARP;
	448	dev->hard_header_len = LL_MAX_HEADER;
1da177e4 LT	449	}
	450
	451	static LIST_HEAD(master_dev_list);
	452	static int max_equalizers = 1;
	453	module_param(max_equalizers, int, 0);
	454	MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
	455
	456	static int __init teql_init(void)
	457	{
	458	int i;
	459	int err = -ENODEV;
	460
	461	for (i = 0; i < max_equalizers; i++) {
	462	struct net_device *dev;
	463	struct teql_master *master;
	464
	465	dev = alloc_netdev(sizeof(struct teql_master),
	466	"teql%d", teql_master_setup);
	467	if (!dev) {
	468	err = -ENOMEM;
	469	break;
	470	}
	471
	472	if ((err = register_netdev(dev))) {
	473	free_netdev(dev);
	474	break;
	475	}
	476
2941a486	477	master = netdev_priv(dev);
1da177e4 LT	478
	479	strlcpy(master->qops.id, dev->name, IFNAMSIZ);
	480	err = register_qdisc(&master->qops);
	481
	482	if (err) {
	483	unregister_netdev(dev);
	484	free_netdev(dev);
	485	break;
	486	}
	487
	488	list_add_tail(&master->master_list, &master_dev_list);
	489	}
	490	return i ? 0 : err;
	491	}
	492
10297b99	493	static void __exit teql_exit(void)
1da177e4 LT	494	{
	495	struct teql_master master, nxt;
	496
	497	list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
	498
	499	list_del(&master->master_list);
	500
	501	unregister_qdisc(&master->qops);
	502	unregister_netdev(master->dev);
	503	free_netdev(master->dev);
	504	}
	505	}
	506
	507	module_init(teql_init);
	508	module_exit(teql_exit);
	509
	510	MODULE_LICENSE("GPL");