misc: add more list methods

The following methods are added:
- nl_list_insert_before
- nl_list_insert_after
- nl_list_insert_list_after
- nl_list_join
- nl_list_last_entry
- nl_list_for_each_entry_reverse
- nl_list_for_each_entry_safe_reverse

These methods are added to support an upcoming patch implementing bridge
vlan support which requires additional list operations to be available.

Author: ronand-atl

include/netlink/list.h

@@ -46,6 +46,35 @@ static inline void nl_list_add_head(struct nl_list_head *obj,
 	__nl_list_add(obj, head, head->next);
 }
 
+static inline void nl_list_insert_before(struct nl_list_head *obj,
+					 struct nl_list_head *ref)
+{
+	__nl_list_add(obj, ref->prev, ref);
+}
+
+static inline void nl_list_insert_after(struct nl_list_head *obj,
+					struct nl_list_head *ref)
+{
+	__nl_list_add(obj, ref, ref->next);
+}
+
+static inline void nl_list_insert_list_after(struct nl_list_head *head,
+					     struct nl_list_head *ref)
+{
+	ref->next->prev = head->prev;
+	head->prev->next = ref->next;
+	ref->next = head->next;
+	head->next->prev = ref;
+	head->next = head;
+	head->prev = head;
+}
+
+static inline void nl_list_join(struct nl_list_head *head_1,
+				struct nl_list_head *head_2)
+{
+	nl_list_insert_list_after(head_2, head_1->prev);
+}
+
 static inline void nl_list_del(struct nl_list_head *obj)
 {
 	obj->next->prev = obj->prev;
@@ -76,17 +105,31 @@ static inline int nl_list_empty(struct nl_list_head *head)
 #define nl_list_first_entry(head, type, member)			\
 	nl_list_entry((head)->next, type, member)
 
+#define nl_list_last_entry(head, type, member)			\
+	nl_list_entry((head)->prev, type, member)
+
 #define nl_list_for_each_entry(pos, head, member)				\
 	for (pos = nl_list_entry((head)->next, __typeof__(*pos), member);	\
 	     &(pos)->member != (head); 	\
 	     (pos) = nl_list_entry((pos)->member.next, __typeof__(*(pos)), member))
 
+#define nl_list_for_each_entry_reverse(pos, head, member)			\
+	for (pos = nl_list_entry((head)->prev, __typeof__(*pos), member);	\
+	     &(pos)->member != (head); 	\
+	     (pos) = nl_list_entry((pos)->member.prev, __typeof__(*(pos)), member))
+
 #define nl_list_for_each_entry_safe(pos, n, head, member)			\
 	for (pos = nl_list_entry((head)->next, __typeof__(*pos), member),	\
 		n = nl_list_entry(pos->member.next, __typeof__(*pos), member);	\
 	     &(pos)->member != (head); 					\
 	     pos = n, n = nl_list_entry(n->member.next, __typeof__(*n), member))
 
+#define nl_list_for_each_entry_safe_reverse(pos, n, head, member)		\
+	for (pos = nl_list_entry((head)->prev, __typeof__(*pos), member),	\
+		n = nl_list_entry(pos->member.prev, __typeof__(*pos), member);	\
+	     &(pos)->member != (head); 					\
+	     pos = n, n = nl_list_entry(n->member.prev, __typeof__(*n), member))
+
 #define nl_init_list_head(head) \
 	do { (head)->next = (head); (head)->prev = (head); } while (0)