iptables: Get rid of the iterator macro

Instead implement the iterator loop directly. Since both dump_entry()
and add_entry() have calculated 'builtin' and 'offset' let's pass in
them in as well.

In the next step we are able to remove also the table argument
which will allow us to unify the parsing the table we get
from IPT_SO_GET_ENTRIES and the table we will pass in to the kernel
via IPT_SO_SET_REPLACE.

1 files changed, 60 insertions, 57 deletions

diff --git a/src/iptables.c b/src/iptables.c
index 3e4513fd..67dff38d 100644
--- a/src/iptables.c
+++ b/src/iptables.c
@@ -142,34 +142,6 @@ static const char *hooknames[] = {
 
 #define XT_OPTION_OFFSET_SCALE 256
 
-/* fn returns 0 to continue iteration */
-#define _XT_ENTRY_ITERATE_CONTINUE(type, entries, size, n, fn, args...) \
-({								\
-	unsigned int __i;					\
-	int __n;						\
-	int __ret = 0;						\
-	type *__entry;						\
-								\
-	for (__i = 0, __n = 0; __i < (size);			\
-	     __i += __entry->next_offset, __n++) {		\
-		__entry = (void *)(entries) + __i;		\
-		if (__n < n)					\
-			continue;				\
-								\
-		__ret = fn(__entry,  ## args);			\
-		if (__ret != 0)					\
-			break;					\
-	}							\
-	__ret;							\
-})
-
-/* fn returns 0 to continue iteration */
-#define _XT_ENTRY_ITERATE(type, entries, size, fn, args...) \
-	_XT_ENTRY_ITERATE_CONTINUE(type, entries, size, 0, fn, args)
-
-#define ENTRY_ITERATE(entries, size, fn, args...) \
-	_XT_ENTRY_ITERATE(struct ipt_entry, entries, size, fn, ## args)
-
 #define MIN_ALIGN (__alignof__(struct ipt_entry))
 
 #define ALIGN(s) (((s) + ((MIN_ALIGN)-1)) & ~((MIN_ALIGN)-1))
@@ -204,25 +176,57 @@ struct connman_iptables {
 
 static GHashTable *table_hash = NULL;
 
-static struct ipt_entry *get_entry(struct connman_iptables *table,
-					unsigned int offset)
+typedef int (*iterate_entries_cb_t)(struct connman_iptables *table,
+					struct ipt_entry *entry, int builtin,
+					unsigned int hook, unsigned int offset,
+					void *user_data);
+
+static int iterate_entries(struct connman_iptables *table,
+				struct ipt_entry *entries,
+				unsigned int valid_hooks,
+				unsigned int *hook_entry,
+				size_t size, iterate_entries_cb_t cb,
+				void *user_data)
 {
-	return (struct ipt_entry *)((char *)table->blob_entries->entrytable +
-									offset);
-}
+	unsigned int i, h;
+	int builtin, err;
+	struct ipt_entry *entry;
 
-static int is_hook_entry(struct connman_iptables *table,
-				struct ipt_entry *entry)
-{
-	unsigned int i;
+	if (valid_hooks != 0)
+		h = __builtin_ffs(valid_hooks) - 1;
+	else
+		h = NF_INET_NUMHOOKS;
+
+	for (i = 0, entry = entries; i < size;
+			i += entry->next_offset) {
+		builtin = -1;
+		entry = (void *)entries + i;
+
+		/*
+		 * Find next valid hook which offset is higher
+		 * or equal with the current offset.
+		 */
+		if (h < NF_INET_NUMHOOKS) {
+			if (hook_entry[h] < i) {
+				valid_hooks ^= (1 << h);
+
+				if (valid_hooks != 0)
+					h = __builtin_ffs(valid_hooks) - 1;
+				else
+					h = NF_INET_NUMHOOKS;
+			}
+
+			if (hook_entry[h] == i)
+				builtin = h;
+		}
+
+		err = cb(table, entry, builtin, h, i, user_data);
+		if (err < 0)
+			return err;
 
-	for (i = 0; i < NF_INET_NUMHOOKS; i++) {
-		if ((table->info->valid_hooks & (1 << i))
-		&& get_entry(table, table->info->hook_entry[i]) == entry)
-			return i;
 	}
 
-	return -1;
+	return 0;
 }
 
 static unsigned long entry_to_offset(struct connman_iptables *table,
@@ -1206,16 +1210,14 @@ out:
 
 }
 
-static int dump_entry(struct ipt_entry *entry,
-				struct connman_iptables *table)
+static int dump_entry(struct connman_iptables *table,
+			struct ipt_entry *entry, int builtin,
+			unsigned int hook, unsigned int offset,
+			void *user_data)
 {
 	struct xt_entry_target *target;
-	unsigned int offset;
-	int builtin;
 
-	offset = (char *)entry - (char *)table->blob_entries->entrytable;
 	target = ipt_get_target(entry);
-	builtin = is_hook_entry(table, entry);
 
 	if (entry_to_offset(table, entry) + entry->next_offset ==
 					table->blob_entries->size) {
@@ -1256,9 +1258,11 @@ static void iptables_dump(struct connman_iptables *table)
 			table->info->valid_hooks, table->info->num_entries,
 				table->info->size);
 
-	ENTRY_ITERATE(table->blob_entries->entrytable,
+	iterate_entries(table, table->blob_entries->entrytable,
+			table->info->valid_hooks,
+			table->info->hook_entry,
 			table->blob_entries->size,
-			dump_entry, table);
+			dump_entry, NULL);
 
 }
 
@@ -1279,10 +1283,11 @@ static int iptables_replace(struct connman_iptables *table,
 			 sizeof(*r) + r->size);
 }
 
-static int add_entry(struct ipt_entry *entry, struct connman_iptables *table)
+static int add_entry(struct connman_iptables *table, struct ipt_entry *entry,
+			int builtin, unsigned int hook, unsigned offset,
+			void *user_data)
 {
 	struct ipt_entry *new_entry;
-	int builtin;
 
 	new_entry = g_try_malloc0(entry->next_offset);
 	if (new_entry == NULL)
@@ -1290,8 +1295,6 @@ static int add_entry(struct ipt_entry *entry, struct connman_iptables *table)
 
 	memcpy(new_entry, entry, entry->next_offset);
 
-	builtin = is_hook_entry(table, entry);
-
 	return iptables_add_entry(table, new_entry, NULL, builtin);
 }
 
@@ -1387,9 +1390,9 @@ static struct connman_iptables *iptables_init(const char *table_name)
 	memcpy(table->hook_entry, table->info->hook_entry,
 				sizeof(table->info->hook_entry));
 
-	ENTRY_ITERATE(table->blob_entries->entrytable,
-			table->blob_entries->size,
-				add_entry, table);
+	iterate_entries(table, table->blob_entries->entrytable,
+			table->info->valid_hooks, table->info->hook_entry,
+			table->blob_entries->size, add_entry, NULL);
 
 	g_hash_table_insert(table_hash, g_strdup(table_name), table);