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/pkt_cls.h>
#include <net/act_api.h>
#include <net/netlink.h>

static int tcf_action_goto_chain_init(struct tc_action *a, struct tcf_proto *tp)
{
	u32 chain_index = a->tcfa_action & TC_ACT_EXT_VAL_MASK;

	if (!tp)
		return -EINVAL;
	a->goto_chain = tcf_chain_get(tp->chain->block, chain_index, true);
	if (!a->goto_chain)
		return -ENOMEM;
	return 0;
}

static void tcf_action_goto_chain_fini(struct tc_action *a)
{
	tcf_chain_put(a->goto_chain);
}

static void tcf_action_goto_chain_exec(const struct tc_action *a,
				       struct tcf_result *res)
{
	const struct tcf_chain *chain = a->goto_chain;

	res->goto_tp = rcu_dereference_bh(chain->filter_chain);
}

/* XXX: For standalone actions, we don't need a RCU grace period either, because
 * actions are always connected to filters and filters are already destroyed in
 * RCU callbacks, so after a RCU grace period actions are already disconnected
 * from filters. Readers later can not find us.
 */
static void free_tcf(struct tc_action *p)
{
	free_percpu(p->cpu_bstats);
	free_percpu(p->cpu_qstats);

	if (p->act_cookie) {
		kfree(p->act_cookie->data);
		kfree(p->act_cookie);
	}
	if (p->goto_chain)
		tcf_action_goto_chain_fini(p);

	kfree(p);
}

static void tcf_idr_remove(struct tcf_idrinfo *idrinfo, struct tc_action *p)
{
	spin_lock_bh(&idrinfo->lock);
	idr_remove_ext(&idrinfo->action_idr, p->tcfa_index);
	spin_unlock_bh(&idrinfo->lock);
	gen_kill_estimator(&p->tcfa_rate_est);
	free_tcf(p);
}

int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
{
	int ret = 0;

	ASSERT_RTNL();

	if (p) {
		if (bind)
			p->tcfa_bindcnt--;
		else if (strict && p->tcfa_bindcnt > 0)
			return -EPERM;

		p->tcfa_refcnt--;
		if (p->tcfa_bindcnt <= 0 && p->tcfa_refcnt <= 0) {
			if (p->ops->cleanup)
				p->ops->cleanup(p, bind);
			tcf_idr_remove(p->idrinfo, p);
			ret = ACT_P_DELETED;
		}
	}

	return ret;
}
EXPORT_SYMBOL(__tcf_idr_release);

static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
			   struct netlink_callback *cb)
{
	int err = 0, index = -1, s_i