netfilter: xtables: replace XT_ENTRY_ITERATE macro

The macro is replaced by a list.h-like foreach loop. This makes
the code much more inspectable.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>

include/linux/netfilter/x_tables.h

@@ -139,6 +139,7 @@ struct xt_counters_info {
 	__ret;							\
 })
 
+#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
 ({								\
@@ -163,6 +164,14 @@ struct xt_counters_info {
 #define XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
 	XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
 
+#endif /* !__KERNEL__ */
+
+/* pos is normally a struct ipt_entry/ip6t_entry/etc. */
+#define xt_entry_foreach(pos, ehead, esize) \
+	for ((pos) = (typeof(pos))(ehead); \
+	     (pos) < (typeof(pos))((char *)(ehead) + (esize)); \
+	     (pos) = (typeof(pos))((char *)(pos) + (pos)->next_offset))
+
 #ifdef __KERNEL__
 
 #include <linux/netdevice.h>

include/linux/netfilter_arp/arp_tables.h

@@ -211,9 +211,11 @@ static __inline__ struct arpt_entry_target *arpt_get_target(struct arpt_entry *e
 	return (void *)e + e->target_offset;
 }
 
+#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define ARPT_ENTRY_ITERATE(entries, size, fn, args...) \
 	XT_ENTRY_ITERATE(struct arpt_entry, entries, size, fn, ## args)
+#endif
 
 /*
  *	Main firewall chains definitions and global var's definitions.
@@ -291,14 +293,6 @@ compat_arpt_get_target(struct compat_arpt_entry *e)
 
 #define COMPAT_ARPT_ALIGN(s)	COMPAT_XT_ALIGN(s)
 
-/* fn returns 0 to continue iteration */
-#define COMPAT_ARPT_ENTRY_ITERATE(entries, size, fn, args...) \
-	XT_ENTRY_ITERATE(struct compat_arpt_entry, entries, size, fn, ## args)
-
-#define COMPAT_ARPT_ENTRY_ITERATE_CONTINUE(entries, size, n, fn, args...) \
-	XT_ENTRY_ITERATE_CONTINUE(struct compat_arpt_entry, entries, size, n, \
-				  fn, ## args)
-
 #endif /* CONFIG_COMPAT */
 #endif /*__KERNEL__*/
 #endif /* _ARPTABLES_H */

include/linux/netfilter_ipv4/ip_tables.h

@@ -227,9 +227,11 @@ ipt_get_target(struct ipt_entry *e)
 #define IPT_MATCH_ITERATE(e, fn, args...) \
 	XT_MATCH_ITERATE(struct ipt_entry, e, fn, ## args)
 
+#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define IPT_ENTRY_ITERATE(entries, size, fn, args...) \
 	XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
+#endif
 
 /*
  *	Main firewall chains definitions and global var's definitions.
@@ -317,15 +319,6 @@ compat_ipt_get_target(struct compat_ipt_entry *e)
 #define COMPAT_IPT_MATCH_ITERATE(e, fn, args...) \
 	XT_MATCH_ITERATE(struct compat_ipt_entry, e, fn, ## args)
 
-/* fn returns 0 to continue iteration */
-#define COMPAT_IPT_ENTRY_ITERATE(entries, size, fn, args...) \
-	XT_ENTRY_ITERATE(struct compat_ipt_entry, entries, size, fn, ## args)
-
-/* fn returns 0 to continue iteration */
-#define COMPAT_IPT_ENTRY_ITERATE_CONTINUE(entries, size, n, fn, args...) \
-	XT_ENTRY_ITERATE_CONTINUE(struct compat_ipt_entry, entries, size, n, \
-				  fn, ## args)
-
 #endif /* CONFIG_COMPAT */
 #endif /*__KERNEL__*/
 #endif /* _IPTABLES_H */

include/linux/netfilter_ipv6/ip6_tables.h

@@ -284,9 +284,11 @@ ip6t_get_target(struct ip6t_entry *e)
 #define IP6T_MATCH_ITERATE(e, fn, args...) \
 	XT_MATCH_ITERATE(struct ip6t_entry, e, fn, ## args)
 
+#ifndef __KERNEL__
 /* fn returns 0 to continue iteration */
 #define IP6T_ENTRY_ITERATE(entries, size, fn, args...) \
 	XT_ENTRY_ITERATE(struct ip6t_entry, entries, size, fn, ## args)
+#endif
 
 /*
  *	Main firewall chains definitions and global var's definitions.
@@ -345,14 +347,6 @@ compat_ip6t_get_target(struct compat_ip6t_entry *e)
 #define COMPAT_IP6T_MATCH_ITERATE(e, fn, args...) \
 	XT_MATCH_ITERATE(struct compat_ip6t_entry, e, fn, ## args)
 
-/* fn returns 0 to continue iteration */
-#define COMPAT_IP6T_ENTRY_ITERATE(entries, size, fn, args...) \
-	XT_ENTRY_ITERATE(struct compat_ip6t_entry, entries, size, fn, ## args)
-
-#define COMPAT_IP6T_ENTRY_ITERATE_CONTINUE(entries, size, n, fn, args...) \
-	XT_ENTRY_ITERATE_CONTINUE(struct compat_ip6t_entry, entries, size, n, \
-				  fn, ## args)
-
 #endif /* CONFIG_COMPAT */
 #endif /*__KERNEL__*/
 #endif /* _IP6_TABLES_H */