[NETFILTER]: x_tables: add statistic match

Add statistic match which is a combination of the nth and random matches.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/netfilter/xt_statistic.h

@@ -0,0 +1,32 @@
+#ifndef _XT_STATISTIC_H
+#define _XT_STATISTIC_H
+
+enum xt_statistic_mode {
+	XT_STATISTIC_MODE_RANDOM,
+	XT_STATISTIC_MODE_NTH,
+	__XT_STATISTIC_MODE_MAX
+};
+#define XT_STATISTIC_MODE_MAX (__XT_STATISTIC_MODE_MAX - 1)
+
+enum xt_statistic_flags {
+	XT_STATISTIC_INVERT		= 0x1,
+};
+#define XT_STATISTIC_MASK		0x1
+
+struct xt_statistic_info {
+	u_int16_t			mode;
+	u_int16_t			flags;
+	union {
+		struct {
+			u_int32_t	probability;
+		} random;
+		struct {
+			u_int32_t	every;
+			u_int32_t	packet;
+			u_int32_t	count;
+		} nth;
+	} u;
+	struct xt_statistic_info	*master __attribute__((aligned(8)));
+};
+
+#endif /* _XT_STATISTIC_H */