iptables: Replace ALIGN macro with XT_ALIGN macro.

XT_ALIGN macro should be used instead of explicit ALIGN macro to define
struct alignments. In Linux kernel netfilter code it has been used for
IPv6 structs (kernel commit 06e1374a7ed45f1788353a2944a20133adc55649)
and the commonly used IPT_ALIGN(s) usually is defined to use XT_ALIGN
as well and has been renamed as XT_ALIGN in iptables 1.4.11.

XT_ALIGN is defined in linux/netfilter/x_tables.h, included via
xtables.h.

connman/src/iptables.c

@@ -143,10 +143,6 @@ static const char *hooknames[] = {
 
 #define XT_OPTION_OFFSET_SCALE 256
 
-#define MIN_ALIGN (__alignof__(struct ipt_entry))
-
-#define ALIGN(s) (((s) + ((MIN_ALIGN)-1)) & ~((MIN_ALIGN)-1))
-
 struct connman_iptables_entry {
 	int offset;
 	int builtin;
@@ -450,9 +446,9 @@ static void update_targets_reference(struct connman_iptables *table,
 
 		t->verdict = entry_before->offset +
 			modified_entry->entry->target_offset +
-			ALIGN(sizeof(struct xt_standard_target));
+			XT_ALIGN(sizeof(struct xt_standard_target));
 		t->target.u.target_size =
-			ALIGN(sizeof(struct xt_standard_target));
+			XT_ALIGN(sizeof(struct xt_standard_target));
 	}
 }
 
@@ -609,37 +605,37 @@ static int iptables_add_chain(struct connman_iptables *table,
 	 */
 
 	/* head entry */
-	entry_head_size = ALIGN(sizeof(struct ipt_entry)) +
-			ALIGN(sizeof(struct xt_error_target));
+	entry_head_size = XT_ALIGN(sizeof(struct ipt_entry)) +
+			XT_ALIGN(sizeof(struct xt_error_target));
 	entry_head = g_try_malloc0(entry_head_size);
 	if (!entry_head)
 		goto err_head;
 
-	entry_head->target_offset = ALIGN(sizeof(struct ipt_entry));
+	entry_head->target_offset = XT_ALIGN(sizeof(struct ipt_entry));
 	entry_head->next_offset = entry_head_size;
 
 	error = (struct xt_error_target *) entry_head->elems;
 	g_stpcpy(error->target.u.user.name, IPT_ERROR_TARGET);
 	error->target.u.user.target_size =
-					ALIGN(sizeof(struct xt_error_target));
+					XT_ALIGN(sizeof(struct xt_error_target));
 	g_stpcpy(error->errorname, name);
 
 	if (iptables_add_entry(table, entry_head, last, -1, -1) < 0)
 		goto err_head;
 
 	/* tail entry */
-	entry_return_size = ALIGN(sizeof(struct ipt_entry))+
-			ALIGN(sizeof(struct ipt_standard_target));
+	entry_return_size = XT_ALIGN(sizeof(struct ipt_entry))+
+			XT_ALIGN(sizeof(struct ipt_standard_target));
 	entry_return = g_try_malloc0(entry_return_size);
 	if (!entry_return)
 		goto err;
 
-	entry_return->target_offset = ALIGN(sizeof(struct ipt_entry));
+	entry_return->target_offset = XT_ALIGN(sizeof(struct ipt_entry));
 	entry_return->next_offset = entry_return_size;
 
 	standard = (struct ipt_standard_target *) entry_return->elems;
 	standard->target.u.user.target_size =
-				ALIGN(sizeof(struct ipt_standard_target));
+				XT_ALIGN(sizeof(struct ipt_standard_target));
 	standard->verdict = XT_RETURN;
 
 	if (iptables_add_entry(table, entry_return, last, -1, -1) < 0)
@@ -706,18 +702,18 @@ static struct ipt_entry *new_rule(struct ipt_ip *ip,
 	if (xt_t)
 		target_size = xt_t->t->u.target_size;
 	else
-		target_size = ALIGN(sizeof(struct xt_standard_target));
+		target_size = XT_ALIGN(sizeof(struct xt_standard_target));
 
-	new_entry = g_try_malloc0(ALIGN(sizeof(struct ipt_entry)) +
+	new_entry = g_try_malloc0(XT_ALIGN(sizeof(struct ipt_entry)) +
 				target_size + match_size);
 	if (!new_entry)
 		return NULL;
 
 	memcpy(&new_entry->ip, ip, sizeof(struct ipt_ip));
 
-	new_entry->target_offset = ALIGN(sizeof(struct ipt_entry)) +
+	new_entry->target_offset = XT_ALIGN(sizeof(struct ipt_entry)) +
 							match_size;
-	new_entry->next_offset = ALIGN(sizeof(struct ipt_entry)) +
+	new_entry->next_offset = XT_ALIGN(sizeof(struct ipt_entry)) +
 					target_size + match_size;
 
 	match_size = 0;
@@ -1600,7 +1596,7 @@ static struct xtables_target *prepare_target(struct connman_iptables *table,
 	if (!xt_t)
 		return NULL;
 
-	target_size = ALIGN(sizeof(struct ipt_entry_target)) + xt_t->size;
+	target_size = XT_ALIGN(sizeof(struct ipt_entry_target)) + xt_t->size;
 
 	xt_t->t = g_try_malloc0(target_size);
 	if (!xt_t->t)
@@ -1663,7 +1659,7 @@ static struct xtables_match *prepare_matches(struct connman_iptables *table,
 		return NULL;
 
 	xt_m = xtables_find_match(match_name, XTF_LOAD_MUST_SUCCEED, xt_rm);
-	match_size = ALIGN(sizeof(struct ipt_entry_match)) + xt_m->size;
+	match_size = XT_ALIGN(sizeof(struct ipt_entry_match)) + xt_m->size;
 
 	xt_m->m = g_try_malloc0(match_size);
 	if (!xt_m->m)