netfilter: ebt: Use new helper ebt_invalid_target to check target

Use the new helper function ebt_invalid_target instead of the old
macro INVALID_TARGET and other duplicated codes to enhance the readability.

Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/linux/netfilter_bridge/ebtables.h

@@ -122,8 +122,6 @@ extern unsigned int ebt_do_table(struct sk_buff *skb,
 #define BASE_CHAIN (par->hook_mask & (1 << NF_BR_NUMHOOKS))
 /* Clear the bit in the hook mask that tells if the rule is on a base chain */
 #define CLEAR_BASE_CHAIN_BIT (par->hook_mask &= ~(1 << NF_BR_NUMHOOKS))
-/* True if the target is not a standard target */
-#define INVALID_TARGET (info->target < -NUM_STANDARD_TARGETS || info->target >= 0)
 
 static inline bool ebt_invalid_target(int target)
 {

net/bridge/netfilter/ebt_dnat.c

@@ -61,7 +61,7 @@ static int ebt_dnat_tg_check(const struct xt_tgchk_param *par)
 	    (strcmp(par->table, "broute") != 0 ||
 	    hook_mask & ~(1 << NF_BR_BROUTING)))
 		return -EINVAL;
-	if (INVALID_TARGET)
+	if (ebt_invalid_target(info->target))
 		return -EINVAL;
 	return 0;
 }

net/bridge/netfilter/ebt_mark.c

@@ -44,7 +44,7 @@ static int ebt_mark_tg_check(const struct xt_tgchk_param *par)
 	tmp = info->target | ~EBT_VERDICT_BITS;
 	if (BASE_CHAIN && tmp == EBT_RETURN)
 		return -EINVAL;
-	if (tmp < -NUM_STANDARD_TARGETS || tmp >= 0)
+	if (ebt_invalid_target(tmp))
 		return -EINVAL;
 	tmp = info->target & ~EBT_VERDICT_BITS;
 	if (tmp != MARK_SET_VALUE && tmp != MARK_OR_VALUE &&

net/bridge/netfilter/ebt_redirect.c

@@ -47,7 +47,7 @@ static int ebt_redirect_tg_check(const struct xt_tgchk_param *par)
 	    (strcmp(par->table, "broute") != 0 ||
 	    hook_mask & ~(1 << NF_BR_BROUTING)))
 		return -EINVAL;
-	if (INVALID_TARGET)
+	if (ebt_invalid_target(info->target))
 		return -EINVAL;
 	return 0;
 }

net/bridge/netfilter/ebt_snat.c

@@ -51,7 +51,7 @@ static int ebt_snat_tg_check(const struct xt_tgchk_param *par)
 	if (BASE_CHAIN && tmp == EBT_RETURN)
 		return -EINVAL;
 
-	if (tmp < -NUM_STANDARD_TARGETS || tmp >= 0)
+	if (ebt_invalid_target(tmp))
 		return -EINVAL;
 	tmp = info->target | EBT_VERDICT_BITS;
 	if ((tmp & ~NAT_ARP_BIT) != ~NAT_ARP_BIT)