path: root/net/sched/act_api.c

/*
 * net/sched/act_api.c	Packet action API.
 *
 *		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.
 *
 * Author:	Jamal Hadi Salim
 *
 *
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <linux/init.h>
#include <linux/kmod.h>
#include <linux/err.h>
#include <linux/module.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/sch_generic.h>
#include <net/act_api.h>
#include <net/netlink.h>

void tcf_hash_destroy(struct tc_action *a)
{
	struct tcf_common *p = a->priv;
	struct tcf_hashinfo *hinfo = a->ops->hinfo;

	spin_lock_bh(&hinfo->lock);
	hlist_del(&p->tcfc_head);
	spin_unlock_bh(&hinfo->lock);
	gen_kill_estimator(&p->tcfc_bstats,
			   &p->tcfc_rate_est);
	/*
	 * gen_estimator est_timer() might access p->tcfc_lock
	 * or bstats, wait a RCU grace period before freeing p
	 */
	kfree_rcu(p, tcfc_rcu);
}
EXPORT_SYMBOL(tcf_hash_destroy);

int tcf_hash_release(struct tc_action *a, int bind)
{
	struct tcf_common *p = a->priv;
	int ret = 0;

	if (p) {
		if (bind)
			p->tcfc_bindcnt--;
		else if (p->tcfc_bindcnt > 0)
			return -EPERM;

		p->tcfc_refcnt--;
		if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
			if (a->ops->cleanup)
				a->ops->cleanup(a, bind);
			tcf_hash_destroy(a);
			ret = 1;
		}
	}
	return ret;
}
EXPORT_SYMBOL(tcf_hash_release);

static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
			   struct tc_action *a)
{
	struct tcf_hashinfo *hinfo = a->ops->hinfo;
	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(&hinfo->lock);

	s_i = cb->args[0];

	for (i = 0; i < (hinfo->hmask + 1); i++) {
		head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];

		hlist_for_each_entry_rcu(p, head, tcfc_head) {
			index++;
			if (index < s_i)
				continue;
			a->priv = p;
			a->order = n_i;

			nest = nla_nest_start(skb, a->order);
			if (nest == NULL)
				goto nla_put_failure;
			err = tcf_action_dump_1(skb, a, 0, 0);
			if (err < 0) {
				index--;
				nlmsg_trim(skb, nest);
				goto done;
			}
			nla_nest_end(skb, nest);
			n_i++;
			if (n_i >= TCA_ACT_MAX_PRIO)
				goto done;
		}
	}
done:
	spin_unlock_bh(&hinfo->lock);
	if (n_i)
		cb->args[0] += n_i;
	return n_i;

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

static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a)
{
	struct tcf_hashinfo *hinfo = a->ops->hinfo;
	struct hlist_head *head;
	struct hlist_node *n;
	struct tcf_common *p;
<