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Diffstat (limited to 'net/netfilter/xt_statistic.c')
-rw-r--r--net/netfilter/xt_statistic.c37
1 files changed, 18 insertions, 19 deletions
diff --git a/net/netfilter/xt_statistic.c b/net/netfilter/xt_statistic.c
index d8c0f8f1a78..11de55e7a86 100644
--- a/net/netfilter/xt_statistic.c
+++ b/net/netfilter/xt_statistic.c
@@ -12,13 +12,15 @@
#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 {
- uint32_t count;
-};
+ atomic_t count;
+} ____cacheline_aligned_in_smp;
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
@@ -26,48 +28,45 @@ MODULE_DESCRIPTION("Xtables: statistics-based matching (\"Nth\", random)");
MODULE_ALIAS("ipt_statistic");
MODULE_ALIAS("ip6t_statistic");
-static DEFINE_SPINLOCK(nth_lock);
-
static bool
-statistic_mt(const struct sk_buff *skb, const struct xt_match_param *par)
+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)
+ if ((prandom_u32() & 0x7FFFFFFF) < info->u.random.probability)
ret = !ret;
break;
case XT_STATISTIC_MODE_NTH:
- spin_lock_bh(&nth_lock);
- if (info->master->count++ == info->u.nth.every) {
- info->master->count = 0;
+ 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;
- }
- spin_unlock_bh(&nth_lock);
break;
}
return ret;
}
-static bool statistic_mt_check(const struct xt_mtchk_param *par)
+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 false;
+ return -EINVAL;
info->master = kzalloc(sizeof(*info->master), GFP_KERNEL);
- if (info->master == NULL) {
- printk(KERN_ERR KBUILD_MODNAME ": Out of memory\n");
- return false;
- }
- info->master->count = info->u.nth.count;
+ if (info->master == NULL)
+ return -ENOMEM;
+ atomic_set(&info->master->count, info->u.nth.count);
- return true;
+ return 0;
}
static void statistic_mt_destroy(const struct xt_mtdtor_param *par)