[mirror_ubuntu-jammy-kernel.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;

	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;
		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;

	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_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 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
	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;
1ac9ad13 ED	62	unsigned long tx_bytes;
	63	unsigned long tx_packets;
	64	unsigned long tx_errors;
	65	unsigned long tx_dropped;
1da177e4 LT	66	};
	67
	68	struct teql_sched_data
	69	{
	70	struct Qdisc *next;
	71	struct teql_master *m;
	72	struct neighbour *ncache;
	73	struct sk_buff_head q;
	74	};
	75
	76	#define NEXT_SLAVE(q) (((struct teql_sched_data*)qdisc_priv(q))->next)
	77
cc8fd14d	78	#define FMASK (IFF_BROADCAST\|IFF_POINTOPOINT)
1da177e4 LT	79
	80	/* "teql" qdisc routines /
	81
	82	static int
	83	teql_enqueue(struct sk_buff skb, struct Qdisc sch)
	84	{
5ce2d488	85	struct net_device *dev = qdisc_dev(sch);
1da177e4 LT	86	struct teql_sched_data *q = qdisc_priv(sch);
1da177e4 LT	87
4cd8c9e8 KK	88	if (q->q.qlen < dev->tx_queue_len) {
4cd8c9e8 KK	89	__skb_queue_tail(&q->q, skb);
bfe0d029	90	qdisc_bstats_update(sch, skb);
9871e50e	91	return NET_XMIT_SUCCESS;
1da177e4 LT	92	}
1da177e4 LT	93
1da177e4 LT	94	kfree_skb(skb);
	95	sch->qstats.drops++;
	96	return NET_XMIT_DROP;
	97	}
	98
1da177e4 LT	99	static struct sk_buff *
	100	teql_dequeue(struct Qdisc* sch)
	101	{
	102	struct teql_sched_data *dat = qdisc_priv(sch);
b0e1e646	103	struct netdev_queue *dat_queue;
1da177e4 LT	104	struct sk_buff *skb;
	105
	106	skb = __skb_dequeue(&dat->q);
e8a0464c	107	dat_queue = netdev_get_tx_queue(dat->m->dev, 0);
1da177e4	108	if (skb == NULL) {
b0e1e646	109	struct net_device *m = qdisc_dev(dat_queue->qdisc);
1da177e4 LT	110	if (m) {
	111	dat->m->slaves = sch;
	112	netif_wake_queue(m);
	113	}
	114	}
b0e1e646	115	sch->q.qlen = dat->q.qlen + dat_queue->qdisc->q.qlen;
1da177e4 LT	116	return skb;
	117	}
	118
8e3af978 JP	119	static struct sk_buff *
	120	teql_peek(struct Qdisc* sch)
	121	{
	122	/* teql is meant to be used as root qdisc */
	123	return NULL;
	124	}
	125
1da177e4 LT	126	static __inline__ void
	127	teql_neigh_release(struct neighbour *n)
	128	{
	129	if (n)
	130	neigh_release(n);
	131	}
	132
	133	static void
	134	teql_reset(struct Qdisc* sch)
	135	{
	136	struct teql_sched_data *dat = qdisc_priv(sch);
	137
	138	skb_queue_purge(&dat->q);
	139	sch->q.qlen = 0;
	140	teql_neigh_release(xchg(&dat->ncache, NULL));
	141	}
	142
	143	static void
	144	teql_destroy(struct Qdisc* sch)
	145	{
	146	struct Qdisc q, prev;
	147	struct teql_sched_data *dat = qdisc_priv(sch);
	148	struct teql_master *master = dat->m;
	149
	150	if ((prev = master->slaves) != NULL) {
	151	do {
	152	q = NEXT_SLAVE(prev);
	153	if (q == sch) {
	154	NEXT_SLAVE(prev) = NEXT_SLAVE(q);
	155	if (q == master->slaves) {
	156	master->slaves = NEXT_SLAVE(q);
	157	if (q == master->slaves) {
e8a0464c	158	struct netdev_queue *txq;
83874000	159	spinlock_t *root_lock;
e8a0464c DM	160
e8a0464c DM	161	txq = netdev_get_tx_queue(master->dev, 0);
1da177e4	162	master->slaves = NULL;
83874000	163
102396ae	164	root_lock = qdisc_root_sleeping_lock(txq->qdisc);
83874000	165	spin_lock_bh(root_lock);
e8a0464c	166	qdisc_reset(txq->qdisc);
83874000	167	spin_unlock_bh(root_lock);
1da177e4 LT	168	}
	169	}
	170	skb_queue_purge(&dat->q);
	171	teql_neigh_release(xchg(&dat->ncache, NULL));
	172	break;
	173	}
10297b99	174
1da177e4 LT	175	} while ((prev = q) != master->slaves);
	176	}
	177	}
	178
1e90474c	179	static int teql_qdisc_init(struct Qdisc sch, struct nlattr opt)
1da177e4	180	{
5ce2d488	181	struct net_device *dev = qdisc_dev(sch);
1da177e4 LT	182	struct teql_master m = (struct teql_master)sch->ops;
	183	struct teql_sched_data *q = qdisc_priv(sch);
	184
	185	if (dev->hard_header_len > m->dev->hard_header_len)
	186	return -EINVAL;
	187
	188	if (m->dev == dev)
	189	return -ELOOP;
	190
	191	q->m = m;
	192
	193	skb_queue_head_init(&q->q);
	194
	195	if (m->slaves) {
	196	if (m->dev->flags & IFF_UP) {
f64f9e71 JP	197	if ((m->dev->flags & IFF_POINTOPOINT &&
	198	!(dev->flags & IFF_POINTOPOINT)) \|\|
	199	(m->dev->flags & IFF_BROADCAST &&
	200	!(dev->flags & IFF_BROADCAST)) \|\|
	201	(m->dev->flags & IFF_MULTICAST &&
	202	!(dev->flags & IFF_MULTICAST)) \|\|
	203	dev->mtu < m->dev->mtu)
1da177e4 LT	204	return -EINVAL;
	205	} else {
	206	if (!(dev->flags&IFF_POINTOPOINT))
	207	m->dev->flags &= ~IFF_POINTOPOINT;
	208	if (!(dev->flags&IFF_BROADCAST))
	209	m->dev->flags &= ~IFF_BROADCAST;
	210	if (!(dev->flags&IFF_MULTICAST))
	211	m->dev->flags &= ~IFF_MULTICAST;
	212	if (dev->mtu < m->dev->mtu)
	213	m->dev->mtu = dev->mtu;
	214	}
	215	q->next = NEXT_SLAVE(m->slaves);
	216	NEXT_SLAVE(m->slaves) = sch;
	217	} else {
	218	q->next = sch;
	219	m->slaves = sch;
	220	m->dev->mtu = dev->mtu;
	221	m->dev->flags = (m->dev->flags&~FMASK)\|(dev->flags&FMASK);
	222	}
	223	return 0;
	224	}
	225
1da177e4 LT	226
	227	static int
	228	__teql_resolve(struct sk_buff skb, struct sk_buff skb_res, struct net_device *dev)
	229	{
e8a0464c DM	230	struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, 0);
e8a0464c DM	231	struct teql_sched_data *q = qdisc_priv(dev_queue->qdisc);
adf30907	232	struct neighbour *mn = skb_dst(skb)->neighbour;
1da177e4 LT	233	struct neighbour *n = q->ncache;
	234
	235	if (mn->tbl == NULL)
	236	return -EINVAL;
	237	if (n && n->tbl == mn->tbl &&
	238	memcmp(n->primary_key, mn->primary_key, mn->tbl->key_len) == 0) {
	239	atomic_inc(&n->refcnt);
	240	} else {
	241	n = __neigh_lookup_errno(mn->tbl, mn->primary_key, dev);
	242	if (IS_ERR(n))
	243	return PTR_ERR(n);
	244	}
	245	if (neigh_event_send(n, skb_res) == 0) {
	246	int err;
0ed8ddf4	247	char haddr[MAX_ADDR_LEN];
0c4e8581	248
0ed8ddf4 ED	249	neigh_ha_snapshot(haddr, n, dev);
	250	err = dev_hard_header(skb, dev, ntohs(skb->protocol), haddr,
	251	NULL, skb->len);
0c4e8581	252
1da177e4 LT	253	if (err < 0) {
	254	neigh_release(n);
	255	return -EINVAL;
	256	}
	257	teql_neigh_release(xchg(&q->ncache, n));
	258	return 0;
	259	}
	260	neigh_release(n);
	261	return (skb_res == NULL) ? -EAGAIN : 1;
	262	}
	263
3b04ddde SH	264	static inline int teql_resolve(struct sk_buff *skb,
3b04ddde SH	265	struct sk_buff skb_res, struct net_device dev)
1da177e4	266	{
e8a0464c DM	267	struct netdev_queue *txq = netdev_get_tx_queue(dev, 0);
e8a0464c DM	268	if (txq->qdisc == &noop_qdisc)
4f9f8311 EP	269	return -ENODEV;
4f9f8311 EP	270
3b04ddde	271	if (dev->header_ops == NULL \|\|
adf30907 ED	272	skb_dst(skb) == NULL \|\|
adf30907 ED	273	skb_dst(skb)->neighbour == NULL)
1da177e4 LT	274	return 0;
	275	return __teql_resolve(skb, skb_res, dev);
	276	}
	277
6fef4c0c	278	static netdev_tx_t teql_master_xmit(struct sk_buff skb, struct net_device dev)
1da177e4	279	{
2941a486	280	struct teql_master *master = netdev_priv(dev);
1da177e4 LT	281	struct Qdisc start, q;
	282	int busy;
	283	int nores;
4e3ab47a	284	int subq = skb_get_queue_mapping(skb);
1da177e4 LT	285	struct sk_buff *skb_res = NULL;
	286
	287	start = master->slaves;
	288
	289	restart:
	290	nores = 0;
	291	busy = 0;
	292
	293	if ((q = start) == NULL)
	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	{
	358	struct Qdisc * q;
2941a486	359	struct teql_master *m = netdev_priv(dev);
1da177e4 LT	360	int mtu = 0xFFFE;
	361	unsigned flags = IFF_NOARP\|IFF_MULTICAST;
	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 LT	428	return -EINVAL;
	429	} while ((q=NEXT_SLAVE(q)) != m->slaves);
	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");