diff options
Diffstat (limited to 'net/netfilter/xt_statistic.c')
| -rw-r--r-- | net/netfilter/xt_statistic.c | 37 |
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) |
