3a9a231d97
With calls to modular infrastructure, these files really needs the full module.h header. Call it out so some of the cleanups of implicit and unrequired includes elsewhere can be cleaned up. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
102 lines
2.5 KiB
C
102 lines
2.5 KiB
C
/*
|
|
* Copyright (c) 2006 Patrick McHardy <kaber@trash.net>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*
|
|
* Based on ipt_random and ipt_nth by Fabrice MARIE <fabrice@netfilter.org>.
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/net.h>
|
|
#include <linux/slab.h>
|
|
|
|
#include <linux/netfilter/xt_statistic.h>
|
|
#include <linux/netfilter/x_tables.h>
|
|
#include <linux/module.h>
|
|
|
|
struct xt_statistic_priv {
|
|
atomic_t count;
|
|
} ____cacheline_aligned_in_smp;
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
|
|
MODULE_DESCRIPTION("Xtables: statistics-based matching (\"Nth\", random)");
|
|
MODULE_ALIAS("ipt_statistic");
|
|
MODULE_ALIAS("ip6t_statistic");
|
|
|
|
static bool
|
|
statistic_mt(const struct sk_buff *skb, struct xt_action_param *par)
|
|
{
|
|
const struct xt_statistic_info *info = par->matchinfo;
|
|
bool ret = info->flags & XT_STATISTIC_INVERT;
|
|
int nval, oval;
|
|
|
|
switch (info->mode) {
|
|
case XT_STATISTIC_MODE_RANDOM:
|
|
if ((net_random() & 0x7FFFFFFF) < info->u.random.probability)
|
|
ret = !ret;
|
|
break;
|
|
case XT_STATISTIC_MODE_NTH:
|
|
do {
|
|
oval = atomic_read(&info->master->count);
|
|
nval = (oval == info->u.nth.every) ? 0 : oval + 1;
|
|
} while (atomic_cmpxchg(&info->master->count, oval, nval) != oval);
|
|
if (nval == 0)
|
|
ret = !ret;
|
|
break;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int statistic_mt_check(const struct xt_mtchk_param *par)
|
|
{
|
|
struct xt_statistic_info *info = par->matchinfo;
|
|
|
|
if (info->mode > XT_STATISTIC_MODE_MAX ||
|
|
info->flags & ~XT_STATISTIC_MASK)
|
|
return -EINVAL;
|
|
|
|
info->master = kzalloc(sizeof(*info->master), GFP_KERNEL);
|
|
if (info->master == NULL)
|
|
return -ENOMEM;
|
|
atomic_set(&info->master->count, info->u.nth.count);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void statistic_mt_destroy(const struct xt_mtdtor_param *par)
|
|
{
|
|
const struct xt_statistic_info *info = par->matchinfo;
|
|
|
|
kfree(info->master);
|
|
}
|
|
|
|
static struct xt_match xt_statistic_mt_reg __read_mostly = {
|
|
.name = "statistic",
|
|
.revision = 0,
|
|
.family = NFPROTO_UNSPEC,
|
|
.match = statistic_mt,
|
|
.checkentry = statistic_mt_check,
|
|
.destroy = statistic_mt_destroy,
|
|
.matchsize = sizeof(struct xt_statistic_info),
|
|
.me = THIS_MODULE,
|
|
};
|
|
|
|
static int __init statistic_mt_init(void)
|
|
{
|
|
return xt_register_match(&xt_statistic_mt_reg);
|
|
}
|
|
|
|
static void __exit statistic_mt_exit(void)
|
|
{
|
|
xt_unregister_match(&xt_statistic_mt_reg);
|
|
}
|
|
|
|
module_init(statistic_mt_init);
|
|
module_exit(statistic_mt_exit);
|