[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/slab.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;
	unsigned long	tx_bytes;
	unsigned long	tx_packets;
	unsigned long	tx_errors;
	unsigned long	tx_dropped;
};

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);
		qdisc_bstats_update(sch, skb);
		return NET_XMIT_SUCCESS;
	}

	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;

	prev = master->slaves;
	if (prev) {
		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;
		char haddr[MAX_ADDR_LEN];

		neigh_ha_snapshot(haddr, n, dev);
		err = dev_hard_header(skb, dev, ntohs(skb->protocol), haddr,
				      NULL, skb->len);

		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 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;

	q = start;
	if (!q)
		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_frozen_or_stopped(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);
					master->tx_packets++;
					master->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;
	}
	master->tx_errors++;

drop:
	master->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 int 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 rtnl_link_stats64 *teql_master_stats64(struct net_device *dev,
						     struct rtnl_link_stats64 *stats)
{
	struct teql_master *m = netdev_priv(dev);

	stats->tx_packets	= m->tx_packets;
	stats->tx_bytes		= m->tx_bytes;
	stats->tx_errors	= m->tx_errors;
	stats->tx_dropped	= m->tx_dropped;
	return 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 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_get_stats64 = teql_master_stats64,
	.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;
	dev->priv_flags		&= ~IFF_XMIT_DST_RELEASE;
}

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>
5a0e3ad6	14	#include <linux/slab.h>
1da177e4	15	#include <linux/string.h>
1da177e4	16	#include <linux/errno.h>
14c85021	17	#include <linux/if_arp.h>
1da177e4	18	#include <linux/netdevice.h>
1da177e4	19	#include <linux/init.h>
1da177e4 LT	20	#include <linux/skbuff.h>
1da177e4 LT	21	#include <linux/moduleparam.h>
0ba48053 PM	22	#include <net/dst.h>
0ba48053 PM	23	#include <net/neighbour.h>
1da177e4 LT	24	#include <net/pkt_sched.h>
	25
	26	/*
	27	How to setup it.
	28	----------------
	29
	30	After loading this module you will find a new device teqlN
	31	and new qdisc with the same name. To join a slave to the equalizer
	32	you should just set this qdisc on a device f.e.
	33
	34	# tc qdisc add dev eth0 root teql0
	35	# tc qdisc add dev eth1 root teql0
	36
	37	That's all. Full PnP 8)
	38
	39	Applicability.
	40	--------------
	41
	42	1. Slave devices MUST be active devices, i.e., they must raise the tbusy
	43	signal and generate EOI events. If you want to equalize virtual devices
	44	like tunnels, use a normal eql device.
	45	2. This device puts no limitations on physical slave characteristics
	46	f.e. it will equalize 9600baud line and 100Mb ethernet perfectly :-)
	47	Certainly, large difference in link speeds will make the resulting
	48	eqalized link unusable, because of huge packet reordering.
	49	I estimate an upper useful difference as ~10 times.
	50	3. If the slave requires address resolution, only protocols using
	51	neighbour cache (IPv4/IPv6) will work over the equalized link.
	52	Other protocols are still allowed to use the slave device directly,
	53	which will not break load balancing, though native slave
	54	traffic will have the highest priority. */
	55
cc7ec456	56	struct teql_master {
1da177e4 LT	57	struct Qdisc_ops qops;
	58	struct net_device *dev;
	59	struct Qdisc *slaves;
	60	struct list_head master_list;
1ac9ad13 ED	61	unsigned long tx_bytes;
	62	unsigned long tx_packets;
	63	unsigned long tx_errors;
	64	unsigned long tx_dropped;
1da177e4 LT	65	};
1da177e4 LT	66
cc7ec456	67	struct teql_sched_data {
1da177e4 LT	68	struct Qdisc *next;
	69	struct teql_master *m;
	70	struct neighbour *ncache;
	71	struct sk_buff_head q;
	72	};
	73
cc7ec456	74	#define NEXT_SLAVE(q) (((struct teql_sched_data *)qdisc_priv(q))->next)
1da177e4	75
cc7ec456	76	#define FMASK (IFF_BROADCAST \| IFF_POINTOPOINT)
1da177e4 LT	77
	78	/* "teql" qdisc routines /
	79
	80	static int
cc7ec456	81	teql_enqueue(struct sk_buff skb, struct Qdisc sch)
1da177e4	82	{
5ce2d488	83	struct net_device *dev = qdisc_dev(sch);
1da177e4 LT	84	struct teql_sched_data *q = qdisc_priv(sch);
1da177e4 LT	85
4cd8c9e8 KK	86	if (q->q.qlen < dev->tx_queue_len) {
4cd8c9e8 KK	87	__skb_queue_tail(&q->q, skb);
bfe0d029	88	qdisc_bstats_update(sch, skb);
9871e50e	89	return NET_XMIT_SUCCESS;
1da177e4 LT	90	}
1da177e4 LT	91
1da177e4 LT	92	kfree_skb(skb);
	93	sch->qstats.drops++;
	94	return NET_XMIT_DROP;
	95	}
	96
1da177e4	97	static struct sk_buff *
cc7ec456	98	teql_dequeue(struct Qdisc *sch)
1da177e4 LT	99	{
1da177e4 LT	100	struct teql_sched_data *dat = qdisc_priv(sch);
b0e1e646	101	struct netdev_queue *dat_queue;
1da177e4 LT	102	struct sk_buff *skb;
	103
	104	skb = __skb_dequeue(&dat->q);
e8a0464c	105	dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
1da177e4	106	if (skb == NULL) {
b0e1e646	107	struct net_device *m = qdisc_dev(dat_queue->qdisc);
1da177e4 LT	108	if (m) {
	109	dat->m->slaves = sch;
	110	netif_wake_queue(m);
	111	}
	112	}
b0e1e646	113	sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen;
1da177e4 LT	114	return skb;
	115	}
	116
8e3af978	117	static struct sk_buff *
cc7ec456	118	teql_peek(struct Qdisc *sch)
8e3af978 JP	119	{
	120	/* teql is meant to be used as root qdisc */
	121	return NULL;
	122	}
	123
cc7ec456	124	static inline void
1da177e4 LT	125	teql_neigh_release(struct neighbour *n)
	126	{
	127	if (n)
	128	neigh_release(n);
	129	}
	130
	131	static void
cc7ec456	132	teql_reset(struct Qdisc *sch)
1da177e4 LT	133	{
	134	struct teql_sched_data *dat = qdisc_priv(sch);
	135
	136	skb_queue_purge(&dat->q);
	137	sch->q.qlen = 0;
	138	teql_neigh_release(xchg(&dat->ncache, NULL));
	139	}
	140
	141	static void
cc7ec456	142	teql_destroy(struct Qdisc *sch)
1da177e4 LT	143	{
	144	struct Qdisc q, prev;
	145	struct teql_sched_data *dat = qdisc_priv(sch);
	146	struct teql_master *master = dat->m;
	147
cc7ec456 ED	148	prev = master->slaves;
cc7ec456 ED	149	if (prev) {
1da177e4 LT	150	do {
	151	q = NEXT_SLAVE(prev);
	152	if (q == sch) {
	153	NEXT_SLAVE(prev) = NEXT_SLAVE(q);
	154	if (q == master->slaves) {
	155	master->slaves = NEXT_SLAVE(q);
	156	if (q == master->slaves) {
e8a0464c	157	struct netdev_queue *txq;
83874000	158	spinlock_t *root_lock;
e8a0464c DM	159
e8a0464c DM	160	txq = netdev_get_tx_queue(master->dev, 0);
1da177e4	161	master->slaves = NULL;
83874000	162
102396ae	163	root_lock = qdisc_root_sleeping_lock(txq->qdisc);
83874000	164	spin_lock_bh(root_lock);
e8a0464c	165	qdisc_reset(txq->qdisc);
83874000	166	spin_unlock_bh(root_lock);
1da177e4 LT	167	}
	168	}
	169	skb_queue_purge(&dat->q);
	170	teql_neigh_release(xchg(&dat->ncache, NULL));
	171	break;
	172	}
10297b99	173
1da177e4 LT	174	} while ((prev = q) != master->slaves);
	175	}
	176	}
	177
1e90474c	178	static int teql_qdisc_init(struct Qdisc sch, struct nlattr opt)
1da177e4	179	{
5ce2d488	180	struct net_device *dev = qdisc_dev(sch);
cc7ec456	181	struct teql_master m = (struct teql_master )sch->ops;
1da177e4 LT	182	struct teql_sched_data *q = qdisc_priv(sch);
	183
	184	if (dev->hard_header_len > m->dev->hard_header_len)
	185	return -EINVAL;
	186
	187	if (m->dev == dev)
	188	return -ELOOP;
	189
	190	q->m = m;
	191
	192	skb_queue_head_init(&q->q);
	193
	194	if (m->slaves) {
	195	if (m->dev->flags & IFF_UP) {
f64f9e71 JP	196	if ((m->dev->flags & IFF_POINTOPOINT &&
	197	!(dev->flags & IFF_POINTOPOINT)) \|\|
	198	(m->dev->flags & IFF_BROADCAST &&
	199	!(dev->flags & IFF_BROADCAST)) \|\|
	200	(m->dev->flags & IFF_MULTICAST &&
	201	!(dev->flags & IFF_MULTICAST)) \|\|
	202	dev->mtu < m->dev->mtu)
1da177e4 LT	203	return -EINVAL;
	204	} else {
	205	if (!(dev->flags&IFF_POINTOPOINT))
	206	m->dev->flags &= ~IFF_POINTOPOINT;
	207	if (!(dev->flags&IFF_BROADCAST))
	208	m->dev->flags &= ~IFF_BROADCAST;
	209	if (!(dev->flags&IFF_MULTICAST))
	210	m->dev->flags &= ~IFF_MULTICAST;
	211	if (dev->mtu < m->dev->mtu)
	212	m->dev->mtu = dev->mtu;
	213	}
	214	q->next = NEXT_SLAVE(m->slaves);
	215	NEXT_SLAVE(m->slaves) = sch;
	216	} else {
	217	q->next = sch;
	218	m->slaves = sch;
	219	m->dev->mtu = dev->mtu;
	220	m->dev->flags = (m->dev->flags&~FMASK)\|(dev->flags&FMASK);
	221	}
	222	return 0;
	223	}
	224
1da177e4 LT	225
	226	static int
	227	__teql_resolve(struct sk_buff skb, struct sk_buff skb_res, struct net_device *dev)
	228	{
e8a0464c DM	229	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
e8a0464c DM	230	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);
adf30907	231	struct neighbour *mn = skb_dst(skb)->neighbour;
1da177e4 LT	232	struct neighbour *n = q->ncache;
	233
	234	if (mn->tbl == NULL)
	235	return -EINVAL;
	236	if (n && n->tbl == mn->tbl &&
	237	memcmp(n->primary_key, mn->primary_key, mn->tbl->key_len) == 0) {
	238	atomic_inc(&n->refcnt);
	239	} else {
	240	n = __neigh_lookup_errno(mn->tbl, mn->primary_key, dev);
	241	if (IS_ERR(n))
	242	return PTR_ERR(n);
	243	}
	244	if (neigh_event_send(n, skb_res) == 0) {
	245	int err;
0ed8ddf4	246	char haddr[MAX_ADDR_LEN];
0c4e8581	247
0ed8ddf4 ED	248	neigh_ha_snapshot(haddr, n, dev);
	249	err = dev_hard_header(skb, dev, ntohs(skb->protocol), haddr,
	250	NULL, skb->len);
0c4e8581	251
1da177e4 LT	252	if (err < 0) {
	253	neigh_release(n);
	254	return -EINVAL;
	255	}
	256	teql_neigh_release(xchg(&q->ncache, n));
	257	return 0;
	258	}
	259	neigh_release(n);
	260	return (skb_res == NULL) ? -EAGAIN : 1;
	261	}
	262
3b04ddde SH	263	static inline int teql_resolve(struct sk_buff *skb,
3b04ddde SH	264	struct sk_buff skb_res, struct net_device dev)
1da177e4	265	{
e8a0464c DM	266	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
e8a0464c DM	267	if (txq->qdisc == &noop_qdisc)
4f9f8311 EP	268	return -ENODEV;
4f9f8311 EP	269
3b04ddde	270	if (dev->header_ops == NULL \|\|
adf30907 ED	271	skb_dst(skb) == NULL \|\|
adf30907 ED	272	skb_dst(skb)->neighbour == NULL)
1da177e4 LT	273	return 0;
	274	return __teql_resolve(skb, skb_res, dev);
	275	}
	276
6fef4c0c	277	static netdev_tx_t teql_master_xmit(struct sk_buff skb, struct net_device dev)
1da177e4	278	{
2941a486	279	struct teql_master *master = netdev_priv(dev);
1da177e4 LT	280	struct Qdisc start, q;
	281	int busy;
	282	int nores;
4e3ab47a	283	int subq = skb_get_queue_mapping(skb);
1da177e4 LT	284	struct sk_buff *skb_res = NULL;
	285
	286	start = master->slaves;
	287
	288	restart:
	289	nores = 0;
	290	busy = 0;
	291
cc7ec456 ED	292	q = start;
cc7ec456 ED	293	if (!q)
1da177e4 LT	294	goto drop;
	295
	296	do {
5ce2d488	297	struct net_device *slave = qdisc_dev(q);
61294e2e SH	298	struct netdev_queue *slave_txq = netdev_get_tx_queue(slave, 0);
61294e2e SH	299	const struct net_device_ops *slave_ops = slave->netdev_ops;
10297b99	300
e8a0464c	301	if (slave_txq->qdisc_sleeping != q)
1da177e4	302	continue;
fd2ea0a7	303	if (__netif_subqueue_stopped(slave, subq) \|\|
f25f4e44	304	!netif_running(slave)) {
1da177e4 LT	305	busy = 1;
	306	continue;
	307	}
	308
	309	switch (teql_resolve(skb, skb_res, slave)) {
	310	case 0:
c3f26a26	311	if (__netif_tx_trylock(slave_txq)) {
c0f84d0d ED	312	unsigned int length = qdisc_pkt_len(skb);
c0f84d0d ED	313
5a0d2268	314	if (!netif_tx_queue_frozen_or_stopped(slave_txq) &&
6fef4c0c	315	slave_ops->ndo_start_xmit(skb, slave) == NETDEV_TX_OK) {
08baf561	316	txq_trans_update(slave_txq);
c3f26a26	317	__netif_tx_unlock(slave_txq);
1da177e4 LT	318	master->slaves = NEXT_SLAVE(q);
1da177e4 LT	319	netif_wake_queue(dev);
1ac9ad13 ED	320	master->tx_packets++;
1ac9ad13 ED	321	master->tx_bytes += length;
6ed10654	322	return NETDEV_TX_OK;
1da177e4	323	}
c3f26a26	324	__netif_tx_unlock(slave_txq);
1da177e4 LT	325	}
	326	if (netif_queue_stopped(dev))
	327	busy = 1;
	328	break;
	329	case 1:
	330	master->slaves = NEXT_SLAVE(q);
6ed10654	331	return NETDEV_TX_OK;
1da177e4 LT	332	default:
	333	nores = 1;
	334	break;
	335	}
bbe735e4	336	__skb_pull(skb, skb_network_offset(skb));
1da177e4 LT	337	} while ((q = NEXT_SLAVE(q)) != start);
	338
	339	if (nores && skb_res == NULL) {
	340	skb_res = skb;
	341	goto restart;
	342	}
	343
	344	if (busy) {
	345	netif_stop_queue(dev);
5b548140	346	return NETDEV_TX_BUSY;
1da177e4	347	}
1ac9ad13	348	master->tx_errors++;
1da177e4 LT	349
1da177e4 LT	350	drop:
1ac9ad13	351	master->tx_dropped++;
1da177e4	352	dev_kfree_skb(skb);
6ed10654	353	return NETDEV_TX_OK;
1da177e4 LT	354	}
	355
	356	static int teql_master_open(struct net_device *dev)
	357	{
cc7ec456	358	struct Qdisc *q;
2941a486	359	struct teql_master *m = netdev_priv(dev);
1da177e4	360	int mtu = 0xFFFE;
cc7ec456	361	unsigned int flags = IFF_NOARP \| IFF_MULTICAST;
1da177e4 LT	362
	363	if (m->slaves == NULL)
	364	return -EUNATCH;
	365
	366	flags = FMASK;
	367
	368	q = m->slaves;
	369	do {
5ce2d488	370	struct net_device *slave = qdisc_dev(q);
1da177e4 LT	371
	372	if (slave == NULL)
	373	return -EUNATCH;
	374
	375	if (slave->mtu < mtu)
	376	mtu = slave->mtu;
	377	if (slave->hard_header_len > LL_MAX_HEADER)
	378	return -EINVAL;
	379
	380	/* If all the slaves are BROADCAST, master is BROADCAST
	381	If all the slaves are PtP, master is PtP
	382	Otherwise, master is NBMA.
	383	*/
	384	if (!(slave->flags&IFF_POINTOPOINT))
	385	flags &= ~IFF_POINTOPOINT;
	386	if (!(slave->flags&IFF_BROADCAST))
	387	flags &= ~IFF_BROADCAST;
	388	if (!(slave->flags&IFF_MULTICAST))
	389	flags &= ~IFF_MULTICAST;
	390	} while ((q = NEXT_SLAVE(q)) != m->slaves);
	391
	392	m->dev->mtu = mtu;
	393	m->dev->flags = (m->dev->flags&~FMASK) \| flags;
	394	netif_start_queue(m->dev);
	395	return 0;
	396	}
	397
	398	static int teql_master_close(struct net_device *dev)
	399	{
	400	netif_stop_queue(dev);
	401	return 0;
	402	}
	403
1ac9ad13 ED	404	static struct rtnl_link_stats64 teql_master_stats64(struct net_device dev,
	405	struct rtnl_link_stats64 *stats)
	406	{
	407	struct teql_master *m = netdev_priv(dev);
	408
	409	stats->tx_packets = m->tx_packets;
	410	stats->tx_bytes = m->tx_bytes;
	411	stats->tx_errors = m->tx_errors;
	412	stats->tx_dropped = m->tx_dropped;
	413	return stats;
	414	}
	415
1da177e4 LT	416	static int teql_master_mtu(struct net_device *dev, int new_mtu)
1da177e4 LT	417	{
2941a486	418	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	419	struct Qdisc *q;
	420
	421	if (new_mtu < 68)
	422	return -EINVAL;
	423
	424	q = m->slaves;
	425	if (q) {
	426	do {
5ce2d488	427	if (new_mtu > qdisc_dev(q)->mtu)
1da177e4	428	return -EINVAL;
cc7ec456	429	} while ((q = NEXT_SLAVE(q)) != m->slaves);
1da177e4 LT	430	}
	431
	432	dev->mtu = new_mtu;
	433	return 0;
	434	}
	435
61294e2e SH	436	static const struct net_device_ops teql_netdev_ops = {
	437	.ndo_open = teql_master_open,
	438	.ndo_stop = teql_master_close,
	439	.ndo_start_xmit = teql_master_xmit,
1ac9ad13	440	.ndo_get_stats64 = teql_master_stats64,
61294e2e SH	441	.ndo_change_mtu = teql_master_mtu,
	442	};
	443
1da177e4 LT	444	static __init void teql_master_setup(struct net_device *dev)
1da177e4 LT	445	{
2941a486	446	struct teql_master *master = netdev_priv(dev);
1da177e4 LT	447	struct Qdisc_ops *ops = &master->qops;
	448
	449	master->dev = dev;
	450	ops->priv_size = sizeof(struct teql_sched_data);
10297b99	451
1da177e4 LT	452	ops->enqueue = teql_enqueue;
1da177e4 LT	453	ops->dequeue = teql_dequeue;
8e3af978	454	ops->peek = teql_peek;
1da177e4 LT	455	ops->init = teql_qdisc_init;
	456	ops->reset = teql_reset;
	457	ops->destroy = teql_destroy;
	458	ops->owner = THIS_MODULE;
	459
61294e2e	460	dev->netdev_ops = &teql_netdev_ops;
1da177e4 LT	461	dev->type = ARPHRD_VOID;
	462	dev->mtu = 1500;
	463	dev->tx_queue_len = 100;
	464	dev->flags = IFF_NOARP;
	465	dev->hard_header_len = LL_MAX_HEADER;
fa68a782	466	dev->priv_flags &= ~IFF_XMIT_DST_RELEASE;
1da177e4 LT	467	}
	468
	469	static LIST_HEAD(master_dev_list);
	470	static int max_equalizers = 1;
	471	module_param(max_equalizers, int, 0);
	472	MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
	473
	474	static int __init teql_init(void)
	475	{
	476	int i;
	477	int err = -ENODEV;
	478
	479	for (i = 0; i < max_equalizers; i++) {
	480	struct net_device *dev;
	481	struct teql_master *master;
	482
	483	dev = alloc_netdev(sizeof(struct teql_master),
	484	"teql%d", teql_master_setup);
	485	if (!dev) {
	486	err = -ENOMEM;
	487	break;
	488	}
	489
	490	if ((err = register_netdev(dev))) {
	491	free_netdev(dev);
	492	break;
	493	}
	494
2941a486	495	master = netdev_priv(dev);
1da177e4 LT	496
	497	strlcpy(master->qops.id, dev->name, IFNAMSIZ);
	498	err = register_qdisc(&master->qops);
	499
	500	if (err) {
	501	unregister_netdev(dev);
	502	free_netdev(dev);
	503	break;
	504	}
	505
	506	list_add_tail(&master->master_list, &master_dev_list);
	507	}
	508	return i ? 0 : err;
	509	}
	510
10297b99	511	static void __exit teql_exit(void)
1da177e4 LT	512	{
	513	struct teql_master master, nxt;
	514
	515	list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
	516
	517	list_del(&master->master_list);
	518
	519	unregister_qdisc(&master->qops);
	520	unregister_netdev(master->dev);
	521	free_netdev(master->dev);
	522	}
	523	}
	524
	525	module_init(teql_init);
	526	module_exit(teql_exit);
	527
	528	MODULE_LICENSE("GPL");