act_gact.c

/*
 * net/sched/gact.c	Generic 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.
 *
 * copyright 	Jamal Hadi Salim (2002-4)
 *
 */

#include <asm/uaccess.h>
#include <asm/system.h>
#include <linux/bitops.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_gact.h>
#include <net/tc_act/tc_gact.h>

/* use generic hash table */
#define MY_TAB_SIZE	16
#define MY_TAB_MASK	15

static u32 idx_gen;
static struct tcf_gact *tcf_gact_ht[MY_TAB_SIZE];
static DEFINE_RWLOCK(gact_lock);

/* ovewrride the defaults */
#define tcf_st		tcf_gact
#define tc_st		tc_gact
#define tcf_t_lock	gact_lock
#define tcf_ht		tcf_gact_ht

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

#ifdef CONFIG_GACT_PROB
static int gact_net_rand(struct tcf_gact *p)
{
	if (net_random()%p->pval)
		return p->action;
	return p->paction;
}

static int gact_determ(struct tcf_gact *p)
{
	if (p->bstats.packets%p->pval)
		return p->action;
	return p->paction;
}

typedef int (*g_rand)(struct tcf_gact *p);
static g_rand gact_rand[MAX_RAND]= { NULL, gact_net_rand, gact_determ };
#endif

static int tcf_gact_init(struct rtattr *rta, struct rtattr *est,
                         struct tc_action *a, int ovr, int bind)
{
	struct rtattr *tb[TCA_GACT_MAX];
	struct tc_gact *parm;
	struct tcf_gact *p;
	int ret = 0;

	if (rta == NULL || rtattr_parse_nested(tb, TCA_GACT_MAX, rta) < 0)
		return -EINVAL;

	if (tb[TCA_GACT_PARMS - 1] == NULL ||
	    RTA_PAYLOAD(tb[TCA_GACT_PARMS - 1]) < sizeof(*parm))
		return -EINVAL;
	parm = RTA_DATA(tb[TCA_GACT_PARMS - 1]);

	if (tb[TCA_GACT_PROB-1] != NULL)
#ifdef CONFIG_GACT_PROB
		if (RTA_PAYLOAD(tb[TCA_GACT_PROB-1]) < sizeof(struct tc_gact_p))
			return -EINVAL;
#else
		return -EOPNOTSUPP;
#endif

	p = tcf_hash_check(parm->index, a, ovr, bind);
	if (p == NULL) {
		p = tcf_hash_create(parm->index, est, a, sizeof(*p), ovr, bind);
		if (p == NULL)
			return -ENOMEM;
		ret = ACT_P_CREATED;
	} else {
		if (!ovr) {
			tcf_hash_release(p, bind);
			return -EEXIST;
		}
	}

	spin_lock_bh(&p->lock);
	p->action = parm->action;
#ifdef CONFIG_GACT_PROB
	if (tb[TCA_GACT_PROB-1] != NULL) {
		struct tc_gact_p *p_parm = RTA_DATA(tb[TCA_GACT_PROB-1]);
		p->paction = p_parm->paction;
		p->pval    = p_parm->pval;
		p->ptype   = p_parm->ptype;
	}
#endif
	spin_unlock_bh(&p->lock);
	if (ret == ACT_P_CREATED)
		tcf_hash_insert(p);
	return ret;
}

static int
tcf_gact_cleanup(struct tc_action *a, int bind)
{
	struct tcf_gact *p = PRIV(a, gact);

	if (p != NULL)
		return tcf_hash_release(p, bind);
	return 0;
}

static int
tcf_gact(struct sk_buff *skb, struct tc_action *a, struct tcf_result *res)
{
	struct tcf_gact *p = PRIV(a, gact);
	int action = TC_ACT_SHOT;

	spin_lock(&p->lock);
#ifdef CONFIG_GACT_PROB
	if (p->ptype && gact_rand[p->ptype] != NULL)
		action = gact_rand[p->ptype](p);
	else
		action = p->action;
#else
	action = p->action;
#endif
	p->bstats.bytes += skb->len;
	p->bstats.packets++;
	if (action == TC_ACT_SHOT)
		p->qstats.drops++;
	p->tm.lastuse = jiffies;
	spin_unlock(&p->lock);

	return action;
}

static int
tcf_gact_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
	unsigned char *b = skb->tail;
	struct tc_gact opt;
	struct tcf_gact *p = PRIV(a, gact);
	struct tcf_t t;

	opt.index = p->index;
	opt.refcnt = p->refcnt - ref;
	opt.bindcnt = p->bindcnt - bind;
	opt.action = p->action;
	RTA_PUT(skb, TCA_GACT_PARMS, sizeof(opt), &opt);
#ifdef CONFIG_GACT_PROB
	if (p->ptype) {
		struct tc_gact_p p_opt;
		p_opt.paction = p->paction;
		p_opt.pval = p->pval;
		p_opt.ptype = p->ptype;
		RTA_PUT(skb, TCA_GACT_PROB, sizeof(p_opt), &p_opt);
	}
#endif
	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_GACT_TM, sizeof(t), &t);
	return skb->len;

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

static struct tc_action_ops act_gact_ops = {
	.kind		=	"gact",
	.type		=	TCA_ACT_GACT,
	.capab		=	TCA_CAP_NONE,
	.owner		=	THIS_MODULE,
	.act		=	tcf_gact,
	.dump		=	tcf_gact_dump,
	.cleanup	=	tcf_gact_cleanup,
	.lookup		=	tcf_hash_search,
	.init		=	tcf_gact_init,
	.walk		=	tcf_generic_walker
};

MODULE_AUTHOR("Jamal Hadi Salim(2002-4)");
MODULE_DESCRIPTION("Generic Classifier actions");
MODULE_LICENSE("GPL");

static int __init
gact_init_module(void)
{
#ifdef CONFIG_GACT_PROB
	printk("GACT probability on\n");
#else
	printk("GACT probability NOT on\n");
#endif
	return tcf_register_action(&act_gact_ops);
}

static void __exit
gact_cleanup_module(void)
{
	tcf_unregister_action(&act_gact_ops);
}

module_init(gact_init_module);
module_exit(gact_cleanup_module);