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

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

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/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;
};

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>
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
	56	struct teql_master
	57	{
	58	struct Qdisc_ops qops;
	59	struct net_device *dev;
	60	struct Qdisc *slaves;
	61	struct list_head master_list;
1da177e4 LT	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) {
f64f9e71 JP	194	if ((m->dev->flags & IFF_POINTOPOINT &&
	195	!(dev->flags & IFF_POINTOPOINT)) \|\|
	196	(m->dev->flags & IFF_BROADCAST &&
	197	!(dev->flags & IFF_BROADCAST)) \|\|
	198	(m->dev->flags & IFF_MULTICAST &&
	199	!(dev->flags & IFF_MULTICAST)) \|\|
	200	dev->mtu < m->dev->mtu)
1da177e4 LT	201	return -EINVAL;
	202	} else {
	203	if (!(dev->flags&IFF_POINTOPOINT))
	204	m->dev->flags &= ~IFF_POINTOPOINT;
	205	if (!(dev->flags&IFF_BROADCAST))
	206	m->dev->flags &= ~IFF_BROADCAST;
	207	if (!(dev->flags&IFF_MULTICAST))
	208	m->dev->flags &= ~IFF_MULTICAST;
	209	if (dev->mtu < m->dev->mtu)
	210	m->dev->mtu = dev->mtu;
	211	}
	212	q->next = NEXT_SLAVE(m->slaves);
	213	NEXT_SLAVE(m->slaves) = sch;
	214	} else {
	215	q->next = sch;
	216	m->slaves = sch;
	217	m->dev->mtu = dev->mtu;
	218	m->dev->flags = (m->dev->flags&~FMASK)\|(dev->flags&FMASK);
	219	}
	220	return 0;
	221	}
	222
1da177e4 LT	223
	224	static int
	225	__teql_resolve(struct sk_buff skb, struct sk_buff skb_res, struct net_device *dev)
	226	{
e8a0464c DM	227	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
e8a0464c DM	228	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);
adf30907	229	struct neighbour *mn = skb_dst(skb)->neighbour;
1da177e4 LT	230	struct neighbour *n = q->ncache;
	231
	232	if (mn->tbl == NULL)
	233	return -EINVAL;
	234	if (n && n->tbl == mn->tbl &&
	235	memcmp(n->primary_key, mn->primary_key, mn->tbl->key_len) == 0) {
	236	atomic_inc(&n->refcnt);
	237	} else {
	238	n = __neigh_lookup_errno(mn->tbl, mn->primary_key, dev);
	239	if (IS_ERR(n))
	240	return PTR_ERR(n);
	241	}
	242	if (neigh_event_send(n, skb_res) == 0) {
	243	int err;
0c4e8581	244
1da177e4	245	read_lock(&n->lock);
0c4e8581 SH	246	err = dev_hard_header(skb, dev, ntohs(skb->protocol),
0c4e8581 SH	247	n->ha, NULL, skb->len);
1da177e4	248	read_unlock(&n->lock);
0c4e8581	249
1da177e4 LT	250	if (err < 0) {
	251	neigh_release(n);
	252	return -EINVAL;
	253	}
	254	teql_neigh_release(xchg(&q->ncache, n));
	255	return 0;
	256	}
	257	neigh_release(n);
	258	return (skb_res == NULL) ? -EAGAIN : 1;
	259	}
	260
3b04ddde SH	261	static inline int teql_resolve(struct sk_buff *skb,
3b04ddde SH	262	struct sk_buff skb_res, struct net_device dev)
1da177e4	263	{
e8a0464c DM	264	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
e8a0464c DM	265	if (txq->qdisc == &noop_qdisc)
4f9f8311 EP	266	return -ENODEV;
4f9f8311 EP	267
3b04ddde	268	if (dev->header_ops == NULL \|\|
adf30907 ED	269	skb_dst(skb) == NULL \|\|
adf30907 ED	270	skb_dst(skb)->neighbour == NULL)
1da177e4 LT	271	return 0;
	272	return __teql_resolve(skb, skb_res, dev);
	273	}
	274
6fef4c0c	275	static netdev_tx_t teql_master_xmit(struct sk_buff skb, struct net_device dev)
1da177e4	276	{
2941a486	277	struct teql_master *master = netdev_priv(dev);
ab35cd4b	278	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
1da177e4 LT	279	struct Qdisc start, q;
	280	int busy;
	281	int nores;
4e3ab47a	282	int subq = skb_get_queue_mapping(skb);
1da177e4 LT	283	struct sk_buff *skb_res = NULL;
	284
	285	start = master->slaves;
	286
	287	restart:
	288	nores = 0;
	289	busy = 0;
	290
	291	if ((q = start) == NULL)
	292	goto drop;
	293
	294	do {
5ce2d488	295	struct net_device *slave = qdisc_dev(q);
61294e2e SH	296	struct netdev_queue *slave_txq = netdev_get_tx_queue(slave, 0);
61294e2e SH	297	const struct net_device_ops *slave_ops = slave->netdev_ops;
10297b99	298
e8a0464c	299	if (slave_txq->qdisc_sleeping != q)
1da177e4	300	continue;
fd2ea0a7	301	if (__netif_subqueue_stopped(slave, subq) \|\|
f25f4e44	302	!netif_running(slave)) {
1da177e4 LT	303	busy = 1;
	304	continue;
	305	}
	306
	307	switch (teql_resolve(skb, skb_res, slave)) {
	308	case 0:
c3f26a26	309	if (__netif_tx_trylock(slave_txq)) {
c0f84d0d ED	310	unsigned int length = qdisc_pkt_len(skb);
c0f84d0d ED	311
c3f26a26 DM	312	if (!netif_tx_queue_stopped(slave_txq) &&
c3f26a26 DM	313	!netif_tx_queue_frozen(slave_txq) &&
6fef4c0c	314	slave_ops->ndo_start_xmit(skb, slave) == NETDEV_TX_OK) {
08baf561	315	txq_trans_update(slave_txq);
c3f26a26	316	__netif_tx_unlock(slave_txq);
1da177e4 LT	317	master->slaves = NEXT_SLAVE(q);
1da177e4 LT	318	netif_wake_queue(dev);
ab35cd4b ED	319	txq->tx_packets++;
ab35cd4b ED	320	txq->tx_bytes += length;
6ed10654	321	return NETDEV_TX_OK;
1da177e4	322	}
c3f26a26	323	__netif_tx_unlock(slave_txq);
1da177e4 LT	324	}
	325	if (netif_queue_stopped(dev))
	326	busy = 1;
	327	break;
	328	case 1:
	329	master->slaves = NEXT_SLAVE(q);
6ed10654	330	return NETDEV_TX_OK;
1da177e4 LT	331	default:
	332	nores = 1;
	333	break;
	334	}
bbe735e4	335	__skb_pull(skb, skb_network_offset(skb));
1da177e4 LT	336	} while ((q = NEXT_SLAVE(q)) != start);
	337
	338	if (nores && skb_res == NULL) {
	339	skb_res = skb;
	340	goto restart;
	341	}
	342
	343	if (busy) {
	344	netif_stop_queue(dev);
5b548140	345	return NETDEV_TX_BUSY;
1da177e4	346	}
ab35cd4b	347	dev->stats.tx_errors++;
1da177e4 LT	348
1da177e4 LT	349	drop:
ab35cd4b	350	txq->tx_dropped++;
1da177e4	351	dev_kfree_skb(skb);
6ed10654	352	return NETDEV_TX_OK;
1da177e4 LT	353	}
	354
	355	static int teql_master_open(struct net_device *dev)
	356	{
	357	struct Qdisc * q;
2941a486	358	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	359	int mtu = 0xFFFE;
	360	unsigned flags = IFF_NOARP\|IFF_MULTICAST;
	361
	362	if (m->slaves == NULL)
	363	return -EUNATCH;
	364
	365	flags = FMASK;
	366
	367	q = m->slaves;
	368	do {
5ce2d488	369	struct net_device *slave = qdisc_dev(q);
1da177e4 LT	370
	371	if (slave == NULL)
	372	return -EUNATCH;
	373
	374	if (slave->mtu < mtu)
	375	mtu = slave->mtu;
	376	if (slave->hard_header_len > LL_MAX_HEADER)
	377	return -EINVAL;
	378
	379	/* If all the slaves are BROADCAST, master is BROADCAST
	380	If all the slaves are PtP, master is PtP
	381	Otherwise, master is NBMA.
	382	*/
	383	if (!(slave->flags&IFF_POINTOPOINT))
	384	flags &= ~IFF_POINTOPOINT;
	385	if (!(slave->flags&IFF_BROADCAST))
	386	flags &= ~IFF_BROADCAST;
	387	if (!(slave->flags&IFF_MULTICAST))
	388	flags &= ~IFF_MULTICAST;
	389	} while ((q = NEXT_SLAVE(q)) != m->slaves);
	390
	391	m->dev->mtu = mtu;
	392	m->dev->flags = (m->dev->flags&~FMASK) \| flags;
	393	netif_start_queue(m->dev);
	394	return 0;
	395	}
	396
	397	static int teql_master_close(struct net_device *dev)
	398	{
	399	netif_stop_queue(dev);
	400	return 0;
	401	}
	402
1da177e4 LT	403	static int teql_master_mtu(struct net_device *dev, int new_mtu)
1da177e4 LT	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
61294e2e SH	423	static const struct net_device_ops teql_netdev_ops = {
	424	.ndo_open = teql_master_open,
	425	.ndo_stop = teql_master_close,
	426	.ndo_start_xmit = teql_master_xmit,
61294e2e SH	427	.ndo_change_mtu = teql_master_mtu,
	428	};
	429
1da177e4 LT	430	static __init void teql_master_setup(struct net_device *dev)
1da177e4 LT	431	{
2941a486	432	struct teql_master *master = netdev_priv(dev);
1da177e4 LT	433	struct Qdisc_ops *ops = &master->qops;
	434
	435	master->dev = dev;
	436	ops->priv_size = sizeof(struct teql_sched_data);
10297b99	437
1da177e4 LT	438	ops->enqueue = teql_enqueue;
1da177e4 LT	439	ops->dequeue = teql_dequeue;
8e3af978	440	ops->peek = teql_peek;
1da177e4 LT	441	ops->init = teql_qdisc_init;
	442	ops->reset = teql_reset;
	443	ops->destroy = teql_destroy;
	444	ops->owner = THIS_MODULE;
	445
61294e2e	446	dev->netdev_ops = &teql_netdev_ops;
1da177e4 LT	447	dev->type = ARPHRD_VOID;
	448	dev->mtu = 1500;
	449	dev->tx_queue_len = 100;
	450	dev->flags = IFF_NOARP;
	451	dev->hard_header_len = LL_MAX_HEADER;
1da177e4 LT	452	}
	453
	454	static LIST_HEAD(master_dev_list);
	455	static int max_equalizers = 1;
	456	module_param(max_equalizers, int, 0);
	457	MODULE_PARM_DESC(max_equalizers, "Max number of link equalizers");
	458
	459	static int __init teql_init(void)
	460	{
	461	int i;
	462	int err = -ENODEV;
	463
	464	for (i = 0; i < max_equalizers; i++) {
	465	struct net_device *dev;
	466	struct teql_master *master;
	467
	468	dev = alloc_netdev(sizeof(struct teql_master),
	469	"teql%d", teql_master_setup);
	470	if (!dev) {
	471	err = -ENOMEM;
	472	break;
	473	}
	474
	475	if ((err = register_netdev(dev))) {
	476	free_netdev(dev);
	477	break;
	478	}
	479
2941a486	480	master = netdev_priv(dev);
1da177e4 LT	481
	482	strlcpy(master->qops.id, dev->name, IFNAMSIZ);
	483	err = register_qdisc(&master->qops);
	484
	485	if (err) {
	486	unregister_netdev(dev);
	487	free_netdev(dev);
	488	break;
	489	}
	490
	491	list_add_tail(&master->master_list, &master_dev_list);
	492	}
	493	return i ? 0 : err;
	494	}
	495
10297b99	496	static void __exit teql_exit(void)
1da177e4 LT	497	{
	498	struct teql_master master, nxt;
	499
	500	list_for_each_entry_safe(master, nxt, &master_dev_list, master_list) {
	501
	502	list_del(&master->master_list);
	503
	504	unregister_qdisc(&master->qops);
	505	unregister_netdev(master->dev);
	506	free_netdev(master->dev);
	507	}
	508	}
	509
	510	module_init(teql_init);
	511	module_exit(teql_exit);
	512
	513	MODULE_LICENSE("GPL");