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Merge up to 2.6.10.
Merge of 2.6.x-xfs-melb:linux:21010a by kenmcd.

/*
 * net/sched/mirred.c	packet mirroring and redirect actions
 *
 *		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:	Jamal Hadi Salim (2002-4)
 *
 * TODO: Add ingress support (and socket redirect support)
 *
 */

#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/bitops.h>
#include <linux/config.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
#include <linux/tc_act/tc_mirred.h>
#include <net/tc_act/tc_mirred.h>

#include <linux/etherdevice.h>
#include <linux/if_arp.h>


/* use generic hash table */
#define MY_TAB_SIZE     8
#define MY_TAB_MASK     (MY_TAB_SIZE - 1)
static u32 idx_gen;
static struct tcf_mirred *tcf_mirred_ht[MY_TAB_SIZE];
static rwlock_t mirred_lock = RW_LOCK_UNLOCKED;

/* ovewrride the defaults */
#define tcf_st  tcf_mirred
#define tc_st  tc_mirred
#define tcf_t_lock   mirred_lock
#define tcf_ht tcf_mirred_ht

#define CONFIG_NET_ACT_INIT 1
#include <net/pkt_act.h>

static inline int
tcf_mirred_release(struct tcf_mirred *p, int bind)
{
	if (p) {
		if (bind) {
			p->bindcnt--;
		}

		p->refcnt--;
		if(!p->bindcnt && p->refcnt <= 0) {
			dev_put(p->dev);
			tcf_hash_destroy(p);
			return 1;
		}
	}

	return 0;
}

static int
tcf_mirred_init(struct rtattr *rta, struct rtattr *est, struct tc_action *a,int ovr, int bind)
{
	struct rtattr *tb[TCA_MIRRED_MAX];
	struct tc_mirred *parm;
	struct tcf_mirred *p;
	struct net_device *dev = NULL;
	int size = sizeof (*p), new = 0;


	if (rtattr_parse(tb, TCA_MIRRED_MAX, RTA_DATA(rta), RTA_PAYLOAD(rta)) < 0) {
		DPRINTK("tcf_mirred_init BUG in user space couldnt parse properly\n");
		return -1;
	}

	if (NULL == a || NULL == tb[TCA_MIRRED_PARMS - 1]) {
		DPRINTK("BUG: tcf_mirred_init called with NULL params\n");
		return -1;
	}

	parm = RTA_DATA(tb[TCA_MIRRED_PARMS - 1]);

	p = tcf_hash_check(parm, a, ovr, bind);
	if (NULL == p) { /* new */
		p = tcf_hash_create(parm,est,a,size,ovr,bind);
		new = 1;
		if (NULL == p)
			return -1;
	}

	if (parm->ifindex) {
		dev = dev_get_by_index(parm->ifindex);
		if (NULL == dev) {
			printk("BUG: tcf_mirred_init called with bad device\n");
			return -1;
		}
		switch (dev->type) {
			case ARPHRD_TUNNEL:
			case ARPHRD_TUNNEL6:
			case ARPHRD_SIT:
			case ARPHRD_IPGRE:
			case ARPHRD_VOID:
			case ARPHRD_NONE:
				p->ok_push = 0;
				break;
			default:
				p->ok_push = 1;
				break;
		}
	} else {
		if (new) {
			kfree(p);
			return -1;
		}	
	}

	if (new || ovr) {
		spin_lock(&p->lock);
		p->action = parm->action;
		p->eaction = parm->eaction;
		if (parm->ifindex) {
			p->ifindex = parm->ifindex;
			if (ovr)
				dev_put(p->dev);
			p->dev = dev;
		}
		spin_unlock(&p->lock);
	}


	DPRINTK(" tcf_mirred_init index %d action %d eaction %d device %s ifndex %d\n",parm->index,parm->action,parm->eaction,dev->name,parm->ifindex);
	return new;

}

static int
tcf_mirred_cleanup(struct tc_action *a, int bind)
{
	struct tcf_mirred *p;
	p = PRIV(a,mirred);
	if (NULL != p)
		return tcf_mirred_release(p, bind);
	return 0;
}

static int
tcf_mirred(struct sk_buff **pskb, struct tc_action *a)
{
	struct tcf_mirred *p;
	struct net_device *dev;
	struct sk_buff *skb2 = NULL;
	struct sk_buff *skb = *pskb;
	__u32 at = G_TC_AT(skb->tc_verd);

	if (NULL == a) {
		if (net_ratelimit())
			printk("BUG: tcf_mirred called with NULL action!\n");
		return -1;
	}

	p = PRIV(a,mirred);

	if (NULL == p) {
		if (net_ratelimit())
			printk("BUG: tcf_mirred called with NULL params\n");
		return -1;
	}

	spin_lock(&p->lock);

       	dev = p->dev;
	p->tm.lastuse = jiffies;

	if (NULL == dev || !(dev->flags&IFF_UP) ) {
		if (net_ratelimit())
			printk("mirred to Houston: device %s is gone!\n",
					dev?dev->name:"");
bad_mirred:
		if (NULL != skb2)
			kfree_skb(skb2);
		p->qstats.overlimits++;
		p->bstats.bytes += skb->len;
		p->bstats.packets++;
		spin_unlock(&p->lock);
		/* should we be asking for packet to be dropped?
		 * may make sense for redirect case only 
		*/
		return TC_ACT_SHOT;
	} 

	skb2 = skb_clone(skb, GFP_ATOMIC);
	if (skb2 == NULL) {
		goto bad_mirred;
	}
	if (TCA_EGRESS_MIRROR != p->eaction &&
		TCA_EGRESS_REDIR != p->eaction) {
		if (net_ratelimit())
			printk("tcf_mirred unknown action %d\n",p->eaction);
		goto bad_mirred;
	}

	p->bstats.bytes += skb2->len;
	p->bstats.packets++;
	if ( !(at & AT_EGRESS)) {
		if (p->ok_push) {
			skb_push(skb2, skb2->dev->hard_header_len);
		}
	}

	/* mirror is always swallowed */
	if (TCA_EGRESS_MIRROR != p->eaction)
		skb2->tc_verd = SET_TC_FROM(skb2->tc_verd,at);

	skb2->dev = dev;
	skb2->input_dev = skb->dev;
	dev_queue_xmit(skb2);
	spin_unlock(&p->lock);
	return p->action;
}

static int
tcf_mirred_dump(struct sk_buff *skb, struct tc_action *a,int bind, int ref)
{
	unsigned char *b = skb->tail;
	struct tc_mirred opt;
	struct tcf_mirred *p;
	struct tcf_t t;

	p = PRIV(a,mirred);
	if (NULL == p) {
		printk("BUG: tcf_mirred_dump called with NULL params\n");
		goto rtattr_failure;
	}

	opt.index = p->index;
	opt.action = p->action;
	opt.refcnt = p->refcnt - ref;
	opt.bindcnt = p->bindcnt - bind;
	opt.eaction = p->eaction;
	opt.ifindex = p->ifindex;
	DPRINTK(" tcf_mirred_dump index %d action %d eaction %d ifndex %d\n",p->index,p->action,p->eaction,p->ifindex);
	RTA_PUT(skb, TCA_MIRRED_PARMS, sizeof (opt), &opt);
	t.install = jiffies_to_clock_t(jiffies - p->tm.install);
	t.lastuse = jiffies_to_clock_t(jiffies - p->tm.lastuse);
	t.expires = jiffies_to_clock_t(p->tm.expires);
	RTA_PUT(skb, TCA_MIRRED_TM, sizeof (t), &t);
	return skb->len;

      rtattr_failure:
	skb_trim(skb, b - skb->data);
	return -1;
}

static struct tc_action_ops act_mirred_ops = {
	.next		=	NULL,
	.kind		=	"mirred",
	.type		=	TCA_ACT_MIRRED,
	.capab		=	TCA_CAP_NONE,
	.owner		=	THIS_MODULE,
	.act		=	tcf_mirred,
	.dump		=	tcf_mirred_dump,
	.cleanup	=	tcf_mirred_cleanup,
	.lookup		=	tcf_hash_search,
	.init		=	tcf_mirred_init,
	.walk		=	tcf_generic_walker
};

MODULE_AUTHOR("Jamal Hadi Salim(2002)");
MODULE_DESCRIPTION("Device Mirror/redirect actions");
MODULE_LICENSE("GPL");


static int __init
mirred_init_module(void)
{
	printk("Mirror/redirect action on\n");
	return tcf_register_action(&act_mirred_ops);
}

static void __exit
mirred_cleanup_module(void)
{
	tcf_unregister_action(&act_mirred_ops);
}

module_init(mirred_init_module);
module_exit(mirred_cleanup_module);