netfilter: ebt_limit: add CONFIG_COMPAT support

ebt_limit structure is larger on 64 bit systems due
to "long" type used in the (kernel-only) data section.

Setting .compatsize is enough in this case, these values
have no meaning in userspace.
Signed-off-by: Florian Westphal <fwestphal@astaro.com>

net/bridge/netfilter/ebt_limit.c

@@ -84,6 +84,19 @@ static bool ebt_limit_mt_check(const struct xt_mtchk_param *par)
 	return true;
 }
 
+
+#ifdef CONFIG_COMPAT
+/*
+ * no conversion function needed --
+ * only avg/burst have meaningful values in userspace.
+ */
+struct ebt_compat_limit_info {
+	compat_uint_t avg, burst;
+	compat_ulong_t prev;
+	compat_uint_t credit, credit_cap, cost;
+};
+#endif
+
 static struct xt_match ebt_limit_mt_reg __read_mostly = {
 	.name		= "limit",
 	.revision	= 0,
@@ -91,6 +104,9 @@ static struct xt_match ebt_limit_mt_reg __read_mostly = {
 	.match		= ebt_limit_mt,
 	.checkentry	= ebt_limit_mt_check,
 	.matchsize	= sizeof(struct ebt_limit_info),
+#ifdef CONFIG_COMPAT
+	.compatsize	= sizeof(struct ebt_compat_limit_info),
+#endif
 	.me		= THIS_MODULE,
 };