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 tcf_common *p, struct tcf_hashinfo *hinfo)
{
	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
	struct tcf_common **p1p;

	for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
		if (*p1p == p) {
			write_lock_bh(hinfo->lock);
			*p1p = p->tcfc_next;
			write_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);
			return;
		}
	}
	WARN_ON(1);
}
EXPORT_SYMBOL(tcf_hash_destroy);

int tcf_hash_release(struct tcf_common *p, int bind,
		     struct tcf_hashinfo *hinfo)
{
	int ret = 0;

	if (p) {
		if (bind)
			p->tcfc_bindcnt--;

		p->tcfc_refcnt--;
		if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
			tcf_hash_destroy(p, hinfo);
			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)
{
	struct tcf_common *p;
	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
	struct nlattr *nest;

	read_lock_bh(hinfo->lock);

	s_i = cb->args[0];

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

		for (; p; p = p->tcfc_next) {
			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:
	read_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)
{
	struct tcf_common *p, *s_p;
	struct nlattr *nest;
	int i = 0, n_i = 0;

	nest = nla_nest_start(skb, a->order);
	if (nest == NULL)
		goto nla_put_failure;
	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
		goto nla_put_failure;
	for (i = 0; i < (hinfo->hmask + 1); i++) {
		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];

		while (p != NULL) {
			s_p = p->tcfc_next;
			if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
				module_put(a->ops->owner);
			n_i++;
			p = s_p;
		}
	}
	if (nla_put_u32(skb, TCA_FCNT, n_i))
		goto nla_put_failure;
	nla_nest_end(skb, nest);

	return n_i;
nla_put_failure:
	nla_nest_cancel(skb, nest);
	return -EINVAL;
}

int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
		       int type, struct tc_action *a)
{
	struct tcf_hashinfo *hinfo = a->ops->hinfo;

	if (type == RTM_DELACTION) {
		return tcf_del_walker(skb, a, hinfo);
	} else if (type == RTM_GETACTION) {
		return tcf_dump_walker(skb, cb, a, hinfo);
	} else {
		WARN(1, "tcf_generic_walker: unknown action %d\n", type);
		return -EINVAL;
	}
}
EXPORT_SYMBOL(tcf_generic_walker);

struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
{
	struct tcf_common *p;

	read_lock_bh(hinfo->lock);
	for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
	     p = p->tcfc_next) {
		if (p->tcfc_index == index)
			break;
	}
	read_unlock_bh(hinfo->lock);

	return p;
}
EXPORT_SYMBOL(tcf_hash_lookup);

u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
{
	u32 val = *idx_gen;

	do {
		if (++val == 0)
			val = 1;
	} while (tcf_hash_lookup(val, hinfo));

	return (*idx_gen = val);
}
EXPORT_SYMBOL(tcf_hash_new_index);

int tcf_hash_search(struct tc_action *a, u32 index)
{
	struct tcf_hashinfo *hinfo = a->ops->hinfo;
	struct tcf_common *p = tcf_hash_lookup(index, hinfo);

	if (p) {
		a->priv = p;
		return 1;
	}
	return 0;
}
EXPORT_SYMBOL(tcf_hash_search);

struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
				  struct tcf_hashinfo *hinfo)
{
	struct tcf_common *p = NULL<