net/sched/act_police.c - SHIFTPHONES/kernel/common - Gitiles

 /*
  * net/sched/police.c	Input police filter.
  *
  *		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>
  * 		J Hadi Salim (action changes)
  */

 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/skbuff.h>
 #include <linux/rtnetlink.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <net/act_api.h>
 #include <net/netlink.h>

 struct tcf_police {
 	struct tcf_common	common;
 	int			tcfp_result;
 	u32			tcfp_ewma_rate;
 	s64			tcfp_burst;
 	u32			tcfp_mtu;
 	s64			tcfp_toks;
 	s64			tcfp_ptoks;
 	s64			tcfp_mtu_ptoks;
 	s64			tcfp_t_c;
 	struct psched_ratecfg	rate;
 	bool			rate_present;
 	struct psched_ratecfg	peak;
 	bool			peak_present;
 };
 #define to_police(pc)	\
 	container_of(pc, struct tcf_police, common)

 #define POL_TAB_MASK     15
 static u32 police_idx_gen;
 static struct tcf_hashinfo police_hash_info;

 /* old policer structure from before tc actions */
 struct tc_police_compat {
 	u32			index;
 	int			action;
 	u32			limit;
 	u32			burst;
 	u32			mtu;
 	struct tc_ratespec	rate;
 	struct tc_ratespec	peakrate;
 };

 /* Each policer is serialized by its individual spinlock */

 static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb,
 			      int type, struct tc_action *a)
 {
 	struct hlist_head *head;
 	struct tcf_common *p;
 	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
 	struct nlattr *nest;

 	spin_lock_bh(&police_hash_info.lock);

 	s_i = cb->args[0];

 	for (i = 0; i < (POL_TAB_MASK + 1); i++) {
 		head = &police_hash_info.htab[tcf_hash(i, POL_TAB_MASK)];

 		hlist_for_each_entry_rcu(p, head, tcfc_head) {
 			index++;
 			if (index < s_i)
 				continue;
 			a->priv = p;
 			a->order = index;
 			nest = nla_nest_start(skb, a->order);
 			if (nest == NULL)
 				goto nla_put_failure;
 			if (type == RTM_DELACTION)
 				err = tcf_action_dump_1(skb, a, 0, 1);
 			else
 				err = tcf_action_dump_1(skb, a, 0, 0);
 			if (err < 0) {
 				index--;
 				nla_nest_cancel(skb, nest);
 				goto done;
 			}
 			nla_nest_end(skb, nest);
 			n_i++;
 		}
 	}
 done:
 	spin_unlock_bh(&police_hash_info.lock);
 	if (n_i)
 		cb->args[0] += n_i;
 	return n_i;

 nla_put_failure:
 	nla_nest_cancel(skb, nest);
 	goto done;
 }

 static void tcf_police_destroy(struct tcf_police *p)
 {
 	spin_lock_bh(&police_hash_info.lock);
 	hlist_del(&p->tcf_head);
 	spin_unlock_bh(&police_hash_info.lock);
 	gen_kill_estimator(&p->tcf_bstats,
 			   &p->tcf_rate_est);
 	/*
 	 * gen_estimator est_timer() might access p->tcf_lock
 	 * or bstats, wait a RCU grace period before freeing p
 	 */
 	kfree_rcu(p, tcf_rcu);
 }

 static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
 	[TCA_POLICE_RATE]	= { .len = TC_RTAB_SIZE },
 	[TCA_POLICE_PEAKRATE]	= { .len = TC_RTAB_SIZE },
 	[TCA_POLICE_AVRATE]	= { .type = NLA_U32 },
 	[TCA_POLICE_RESULT]	= { .type = NLA_U32 },
 };

 static int tcf_act_police_locate(struct net *net, struct nlattr *nla,
 				 struct nlattr *est, struct tc_action *a,
 				 int ovr, int bind)
 {
 	unsigned int h;
 	int ret = 0, err;
 	struct nlattr *tb[TCA_POLICE_MAX + 1];
 	struct tc_police *parm;
 	struct tcf_police *police;
 	struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
 	int size;

 	if (nla == NULL)
 		return -EINVAL;

 	err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy);
 	if (err < 0)
 		return err;

 	if (tb[TCA_POLICE_TBF] == NULL)
 		return -EINVAL;
 	size = nla_len(tb[TCA_POLICE_TBF]);
 	if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
 		return -EINVAL;
 	parm = nla_data(tb[TCA_POLICE_TBF]);

 	if (parm->index) {
 		struct tcf_common *pc;

 		pc = tcf_hash_lookup(parm->index, &police_hash_info);
 		if (pc != NULL) {
 			a->priv = pc;
 			police = to_police(pc);
 			if (bind) {
 				police->tcf_bindcnt += 1;
 				police->tcf_refcnt += 1;
 			}
 			if (ovr)
 				goto override;
 			return ret;
 		}
 	}

 	police = kzalloc(sizeof(*police), GFP_KERNEL);
 	if (police == NULL)
 		return -ENOMEM;
 	ret = ACT_P_CREATED;
 	police->tcf_refcnt = 1;
 	spin_lock_init(&police->tcf_lock);
 	if (bind)
 		police->tcf_bindcnt = 1;
 override:
 	if (parm->rate.rate) {
 		err = -ENOMEM;
 		R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
 		if (R_tab == NULL)
 			goto failure;

 		if (parm->peakrate.rate) {
 			P_tab = qdisc_get_rtab(&parm->peakrate,
 					       tb[TCA_POLICE_PEAKRATE]);
 			if (P_tab == NULL)
 				goto failure;
 		}
 	}

 	spin_lock_bh(&police->tcf_lock);
 	if (est) {
 		err = gen_replace_estimator(&police->tcf_bstats,
 					    &police->tcf_rate_est,
 					    &police->tcf_lock, est);
 		if (err)
 			goto failure_unlock;
 	} else if (tb[TCA_POLICE_AVRATE] &&
 		   (ret == ACT_P_CREATED ||
 		    !gen_estimator_active(&police->tcf_bstats,
 					  &police->tcf_rate_est))) {
 		err = -EINVAL;
 		goto failure_unlock;
 	}

 	/* No failure allowed after this point */
 	police->tcfp_mtu = parm->mtu;
 	if (police->tcfp_mtu == 0) {
 		police->tcfp_mtu = ~0;
 		if (R_tab)
 			police->tcfp_mtu = 255 << R_tab->rate.cell_log;
 	}
 	if (R_tab) {
 		police->rate_present = true;
 		psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0);
 		qdisc_put_rtab(R_tab);
 	} else {
 		police->rate_present = false;
 	}
 	if (P_tab) {
 		police->peak_present = true;
 		psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0);
 		qdisc_put_rtab(P_tab);
 	} else {
 		police->peak_present = false;
 	}

 	if (tb[TCA_POLICE_RESULT])
 		police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
 	police->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
 	police->tcfp_toks = police->tcfp_burst;
 	if (police->peak_present) {
 		police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak,
 							     police->tcfp_mtu);
 		police->tcfp_ptoks = police->tcfp_mtu_ptoks;
 	}
 	police->tcf_action = parm->action;

 	if (tb[TCA_POLICE_AVRATE])
 		police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);

 	spin_unlock_bh(&police->tcf_lock);
 	if (ret != ACT_P_CREATED)
 		return ret;

 	police->tcfp_t_c = ktime_to_ns(ktime_get());
 	police->tcf_index = parm->index ? parm->index :
 		tcf_hash_new_index(&police_idx_gen, &police_hash_info);
 	h = tcf_hash(police->tcf_index, POL_TAB_MASK);
 	spin_lock_bh(&police_hash_info.lock);
 	hlist_add_head(&police->tcf_head, &police_hash_info.htab[h]);
 	spin_unlock_bh(&police_hash_info.lock);

 	a->priv = police;
 	return ret;

 failure_unlock:
 	spin_unlock_bh(&police->tcf_lock);
 failure:
 	qdisc_put_rtab(P_tab);
 	qdisc_put_rtab(R_tab);
 	if (ret == ACT_P_CREATED)
 		kfree(police);
 	return err;
 }

 static int tcf_act_police_cleanup(struct tc_action *a, int bind)
 {
 	struct tcf_police *p = a->priv;
 	int ret = 0;

 	if (p != NULL) {
 		if (bind)
 			p->tcf_bindcnt--;

 		p->tcf_refcnt--;
 		if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
 			tcf_police_destroy(p);
 			ret = 1;
 		}
 	}
 	return ret;
 }

 static int tcf_act_police(struct sk_buff *skb, const struct tc_action *a,
 			  struct tcf_result *res)
 {
 	struct tcf_police *police = a->priv;
 	s64 now;
 	s64 toks;
 	s64 ptoks = 0;

 	spin_lock(&police->tcf_lock);

 	bstats_update(&police->tcf_bstats, skb);

 	if (police->tcfp_ewma_rate &&
 	    police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
 		police->tcf_qstats.overlimits++;
 		if (police->tcf_action == TC_ACT_SHOT)
 			police->tcf_qstats.drops++;
 		spin_unlock(&police->tcf_lock);
 		return police->tcf_action;
 	}

 	if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
 		if (!police->rate_present) {
 			spin_unlock(&police->tcf_lock);
 			return police->tcfp_result;
 		}

 		now = ktime_to_ns(ktime_get());
 		toks = min_t(s64, now - police->tcfp_t_c,
 			     police->tcfp_burst);
 		if (police->peak_present) {
 			ptoks = toks + police->tcfp_ptoks;
 			if (ptoks > police->tcfp_mtu_ptoks)
 				ptoks = police->tcfp_mtu_ptoks;
 			ptoks -= (s64) psched_l2t_ns(&police->peak,
 						     qdisc_pkt_len(skb));
 		}
 		toks += police->tcfp_toks;
 		if (toks > police->tcfp_burst)
 			toks = police->tcfp_burst;
 		toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb));
 		if ((toks|ptoks) >= 0) {
 			police->tcfp_t_c = now;
 			police->tcfp_toks = toks;
 			police->tcfp_ptoks = ptoks;
 			spin_unlock(&police->tcf_lock);
 			return police->tcfp_result;
 		}
 	}

 	police->tcf_qstats.overlimits++;
 	if (police->tcf_action == TC_ACT_SHOT)
 		police->tcf_qstats.drops++;
 	spin_unlock(&police->tcf_lock);
 	return police->tcf_action;
 }

 static int
 tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
 {
 	unsigned char *b = skb_tail_pointer(skb);
 	struct tcf_police *police = a->priv;
 	struct tc_police opt = {
 		.index = police->tcf_index,
 		.action = police->tcf_action,
 		.mtu = police->tcfp_mtu,
 		.burst = PSCHED_NS2TICKS(police->tcfp_burst),
 		.refcnt = police->tcf_refcnt - ref,
 		.bindcnt = police->tcf_bindcnt - bind,
 	};

 	if (police->rate_present)
 		psched_ratecfg_getrate(&opt.rate, &police->rate);
 	if (police->peak_present)
 		psched_ratecfg_getrate(&opt.peakrate, &police->peak);
 	if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
 		goto nla_put_failure;
 	if (police->tcfp_result &&
 	    nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result))
 		goto nla_put_failure;
 	if (police->tcfp_ewma_rate &&
 	    nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate))
 		goto nla_put_failure;
 	return skb->len;

 nla_put_failure:
 	nlmsg_trim(skb, b);
 	return -1;
 }

 MODULE_AUTHOR("Alexey Kuznetsov");
 MODULE_DESCRIPTION("Policing actions");
 MODULE_LICENSE("GPL");

 static struct tc_action_ops act_police_ops = {
 	.kind		=	"police",
 	.hinfo		=	&police_hash_info,
 	.type		=	TCA_ID_POLICE,
 	.capab		=	TCA_CAP_NONE,
 	.owner		=	THIS_MODULE,
 	.act		=	tcf_act_police,
 	.dump		=	tcf_act_police_dump,
 	.cleanup	=	tcf_act_police_cleanup,
 	.init		=	tcf_act_police_locate,
 	.walk		=	tcf_act_police_walker
 };

 static int __init
 police_init_module(void)
 {
 	int err = tcf_hashinfo_init(&police_hash_info, POL_TAB_MASK+1);
 	if (err)
 		return err;
 	err = tcf_register_action(&act_police_ops);
 	if (err)
 		tcf_hashinfo_destroy(&police_hash_info);
 	return err;
 }

 static void __exit
 police_cleanup_module(void)
 {
 	tcf_hashinfo_destroy(&police_hash_info);
 	tcf_unregister_action(&act_police_ops);
 }

 module_init(police_init_module);
 module_exit(police_cleanup_module);
	/*
	* net/sched/police.c Input police filter.
	*
	* 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>
	* J Hadi Salim (action changes)
	*/

	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/kernel.h>
	#include <linux/string.h>
	#include <linux/errno.h>
	#include <linux/skbuff.h>
	#include <linux/rtnetlink.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <net/act_api.h>
	#include <net/netlink.h>

	struct tcf_police {
	struct tcf_common common;
	int tcfp_result;
	u32 tcfp_ewma_rate;
	s64 tcfp_burst;
	u32 tcfp_mtu;
	s64 tcfp_toks;
	s64 tcfp_ptoks;
	s64 tcfp_mtu_ptoks;
	s64 tcfp_t_c;
	struct psched_ratecfg rate;
	bool rate_present;
	struct psched_ratecfg peak;
	bool peak_present;
	};
	#define to_police(pc) \
	container_of(pc, struct tcf_police, common)

	#define POL_TAB_MASK 15
	static u32 police_idx_gen;
	static struct tcf_hashinfo police_hash_info;

	/* old policer structure from before tc actions */
	struct tc_police_compat {
	u32 index;
	int action;
	u32 limit;
	u32 burst;
	u32 mtu;
	struct tc_ratespec rate;
	struct tc_ratespec peakrate;
	};

	/* Each policer is serialized by its individual spinlock */

	static int tcf_act_police_walker(struct sk_buff skb, struct netlink_callback cb,
	int type, struct tc_action *a)
	{
	struct hlist_head *head;
	struct tcf_common *p;
	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
	struct nlattr *nest;

	spin_lock_bh(&police_hash_info.lock);

	s_i = cb->args[0];

	for (i = 0; i < (POL_TAB_MASK + 1); i++) {
	head = &police_hash_info.htab[tcf_hash(i, POL_TAB_MASK)];

	hlist_for_each_entry_rcu(p, head, tcfc_head) {
	index++;
	if (index < s_i)
	continue;
	a->priv = p;
	a->order = index;
	nest = nla_nest_start(skb, a->order);
	if (nest == NULL)
	goto nla_put_failure;
	if (type == RTM_DELACTION)
	err = tcf_action_dump_1(skb, a, 0, 1);
	else
	err = tcf_action_dump_1(skb, a, 0, 0);
	if (err < 0) {
	index--;
	nla_nest_cancel(skb, nest);
	goto done;
	}
	nla_nest_end(skb, nest);
	n_i++;
	}
	}
	done:
	spin_unlock_bh(&police_hash_info.lock);
	if (n_i)
	cb->args[0] += n_i;
	return n_i;

	nla_put_failure:
	nla_nest_cancel(skb, nest);
	goto done;
	}

	static void tcf_police_destroy(struct tcf_police *p)
	{
	spin_lock_bh(&police_hash_info.lock);
	hlist_del(&p->tcf_head);
	spin_unlock_bh(&police_hash_info.lock);
	gen_kill_estimator(&p->tcf_bstats,
	&p->tcf_rate_est);
	/*
	* gen_estimator est_timer() might access p->tcf_lock
	* or bstats, wait a RCU grace period before freeing p
	*/
	kfree_rcu(p, tcf_rcu);
	}

	static const struct nla_policy police_policy[TCA_POLICE_MAX + 1] = {
	[TCA_POLICE_RATE] = { .len = TC_RTAB_SIZE },
	[TCA_POLICE_PEAKRATE] = { .len = TC_RTAB_SIZE },
	[TCA_POLICE_AVRATE] = { .type = NLA_U32 },
	[TCA_POLICE_RESULT] = { .type = NLA_U32 },
	};

	static int tcf_act_police_locate(struct net net, struct nlattr nla,
	struct nlattr est, struct tc_action a,
	int ovr, int bind)
	{
	unsigned int h;
	int ret = 0, err;
	struct nlattr *tb[TCA_POLICE_MAX + 1];
	struct tc_police *parm;
	struct tcf_police *police;
	struct qdisc_rate_table R_tab = NULL, P_tab = NULL;
	int size;

	if (nla == NULL)
	return -EINVAL;

	err = nla_parse_nested(tb, TCA_POLICE_MAX, nla, police_policy);
	if (err < 0)
	return err;

	if (tb[TCA_POLICE_TBF] == NULL)
	return -EINVAL;
	size = nla_len(tb[TCA_POLICE_TBF]);
	if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
	return -EINVAL;
	parm = nla_data(tb[TCA_POLICE_TBF]);

	if (parm->index) {
	struct tcf_common *pc;

	pc = tcf_hash_lookup(parm->index, &police_hash_info);
	if (pc != NULL) {
	a->priv = pc;
	police = to_police(pc);
	if (bind) {
	police->tcf_bindcnt += 1;
	police->tcf_refcnt += 1;
	}
	if (ovr)
	goto override;
	return ret;
	}
	}

	police = kzalloc(sizeof(*police), GFP_KERNEL);
	if (police == NULL)
	return -ENOMEM;
	ret = ACT_P_CREATED;
	police->tcf_refcnt = 1;
	spin_lock_init(&police->tcf_lock);
	if (bind)
	police->tcf_bindcnt = 1;
	override:
	if (parm->rate.rate) {
	err = -ENOMEM;
	R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
	if (R_tab == NULL)
	goto failure;

	if (parm->peakrate.rate) {
	P_tab = qdisc_get_rtab(&parm->peakrate,
	tb[TCA_POLICE_PEAKRATE]);
	if (P_tab == NULL)
	goto failure;
	}
	}

	spin_lock_bh(&police->tcf_lock);
	if (est) {
	err = gen_replace_estimator(&police->tcf_bstats,
	&police->tcf_rate_est,
	&police->tcf_lock, est);
	if (err)
	goto failure_unlock;
	} else if (tb[TCA_POLICE_AVRATE] &&
	(ret == ACT_P_CREATED \|\|
	!gen_estimator_active(&police->tcf_bstats,
	&police->tcf_rate_est))) {
	err = -EINVAL;
	goto failure_unlock;
	}

	/* No failure allowed after this point */
	police->tcfp_mtu = parm->mtu;
	if (police->tcfp_mtu == 0) {
	police->tcfp_mtu = ~0;
	if (R_tab)
	police->tcfp_mtu = 255 << R_tab->rate.cell_log;
	}
	if (R_tab) {
	police->rate_present = true;
	psched_ratecfg_precompute(&police->rate, &R_tab->rate, 0);
	qdisc_put_rtab(R_tab);
	} else {
	police->rate_present = false;
	}
	if (P_tab) {
	police->peak_present = true;
	psched_ratecfg_precompute(&police->peak, &P_tab->rate, 0);
	qdisc_put_rtab(P_tab);
	} else {
	police->peak_present = false;
	}

	if (tb[TCA_POLICE_RESULT])
	police->tcfp_result = nla_get_u32(tb[TCA_POLICE_RESULT]);
	police->tcfp_burst = PSCHED_TICKS2NS(parm->burst);
	police->tcfp_toks = police->tcfp_burst;
	if (police->peak_present) {
	police->tcfp_mtu_ptoks = (s64) psched_l2t_ns(&police->peak,
	police->tcfp_mtu);
	police->tcfp_ptoks = police->tcfp_mtu_ptoks;
	}
	police->tcf_action = parm->action;

	if (tb[TCA_POLICE_AVRATE])
	police->tcfp_ewma_rate = nla_get_u32(tb[TCA_POLICE_AVRATE]);

	spin_unlock_bh(&police->tcf_lock);
	if (ret != ACT_P_CREATED)
	return ret;

	police->tcfp_t_c = ktime_to_ns(ktime_get());
	police->tcf_index = parm->index ? parm->index :
	tcf_hash_new_index(&police_idx_gen, &police_hash_info);
	h = tcf_hash(police->tcf_index, POL_TAB_MASK);
	spin_lock_bh(&police_hash_info.lock);
	hlist_add_head(&police->tcf_head, &police_hash_info.htab[h]);
	spin_unlock_bh(&police_hash_info.lock);

	a->priv = police;
	return ret;

	failure_unlock:
	spin_unlock_bh(&police->tcf_lock);
	failure:
	qdisc_put_rtab(P_tab);
	qdisc_put_rtab(R_tab);
	if (ret == ACT_P_CREATED)
	kfree(police);
	return err;
	}

	static int tcf_act_police_cleanup(struct tc_action *a, int bind)
	{
	struct tcf_police *p = a->priv;
	int ret = 0;

	if (p != NULL) {
	if (bind)
	p->tcf_bindcnt--;

	p->tcf_refcnt--;
	if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
	tcf_police_destroy(p);
	ret = 1;
	}
	}
	return ret;
	}

	static int tcf_act_police(struct sk_buff skb, const struct tc_action a,
	struct tcf_result *res)
	{
	struct tcf_police *police = a->priv;
	s64 now;
	s64 toks;
	s64 ptoks = 0;

	spin_lock(&police->tcf_lock);

	bstats_update(&police->tcf_bstats, skb);

	if (police->tcfp_ewma_rate &&
	police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
	police->tcf_qstats.overlimits++;
	if (police->tcf_action == TC_ACT_SHOT)
	police->tcf_qstats.drops++;
	spin_unlock(&police->tcf_lock);
	return police->tcf_action;
	}

	if (qdisc_pkt_len(skb) <= police->tcfp_mtu) {
	if (!police->rate_present) {
	spin_unlock(&police->tcf_lock);
	return police->tcfp_result;
	}

	now = ktime_to_ns(ktime_get());
	toks = min_t(s64, now - police->tcfp_t_c,
	police->tcfp_burst);
	if (police->peak_present) {
	ptoks = toks + police->tcfp_ptoks;
	if (ptoks > police->tcfp_mtu_ptoks)
	ptoks = police->tcfp_mtu_ptoks;
	ptoks -= (s64) psched_l2t_ns(&police->peak,
	qdisc_pkt_len(skb));
	}
	toks += police->tcfp_toks;
	if (toks > police->tcfp_burst)
	toks = police->tcfp_burst;
	toks -= (s64) psched_l2t_ns(&police->rate, qdisc_pkt_len(skb));
	if ((toks\|ptoks) >= 0) {
	police->tcfp_t_c = now;
	police->tcfp_toks = toks;
	police->tcfp_ptoks = ptoks;
	spin_unlock(&police->tcf_lock);
	return police->tcfp_result;
	}
	}

	police->tcf_qstats.overlimits++;
	if (police->tcf_action == TC_ACT_SHOT)
	police->tcf_qstats.drops++;
	spin_unlock(&police->tcf_lock);
	return police->tcf_action;
	}

	static int
	tcf_act_police_dump(struct sk_buff skb, struct tc_action a, int bind, int ref)
	{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_police *police = a->priv;
	struct tc_police opt = {
	.index = police->tcf_index,
	.action = police->tcf_action,
	.mtu = police->tcfp_mtu,
	.burst = PSCHED_NS2TICKS(police->tcfp_burst),
	.refcnt = police->tcf_refcnt - ref,
	.bindcnt = police->tcf_bindcnt - bind,
	};

	if (police->rate_present)
	psched_ratecfg_getrate(&opt.rate, &police->rate);
	if (police->peak_present)
	psched_ratecfg_getrate(&opt.peakrate, &police->peak);
	if (nla_put(skb, TCA_POLICE_TBF, sizeof(opt), &opt))
	goto nla_put_failure;
	if (police->tcfp_result &&
	nla_put_u32(skb, TCA_POLICE_RESULT, police->tcfp_result))
	goto nla_put_failure;
	if (police->tcfp_ewma_rate &&
	nla_put_u32(skb, TCA_POLICE_AVRATE, police->tcfp_ewma_rate))
	goto nla_put_failure;
	return skb->len;

	nla_put_failure:
	nlmsg_trim(skb, b);
	return -1;
	}

	MODULE_AUTHOR("Alexey Kuznetsov");
	MODULE_DESCRIPTION("Policing actions");
	MODULE_LICENSE("GPL");

	static struct tc_action_ops act_police_ops = {
	.kind = "police",
	.hinfo = &police_hash_info,
	.type = TCA_ID_POLICE,
	.capab = TCA_CAP_NONE,
	.owner = THIS_MODULE,
	.act = tcf_act_police,
	.dump = tcf_act_police_dump,
	.cleanup = tcf_act_police_cleanup,
	.init = tcf_act_police_locate,
	.walk = tcf_act_police_walker
	};

	static int __init
	police_init_module(void)
	{
	int err = tcf_hashinfo_init(&police_hash_info, POL_TAB_MASK+1);
	if (err)
	return err;
	err = tcf_register_action(&act_police_ops);
	if (err)
	tcf_hashinfo_destroy(&police_hash_info);
	return err;
	}

	static void __exit
	police_cleanup_module(void)
	{
	tcf_hashinfo_destroy(&police_hash_info);
	tcf_unregister_action(&act_police_ops);
	}

	module_init(police_init_module);
	module_exit(police_cleanup_module);