Implement sorting for hash types in the ipset tool

Support listing/saving with sorted entries for the hash types.
(bitmap and list types are automatically sorted.)

1 files changed, 104 insertions, 0 deletions

diff --git a/include/libipset/list_sort.h b/include/libipset/list_sort.h
new file mode 100644
index 0000000..70b1fca
--- /dev/null
+++ b/include/libipset/list_sort.h
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_LIST_SORT_H
+#define _LINUX_LIST_SORT_H
+
+/* List manipulations from include/linux/list.h */
+struct list_head {
+	struct list_head *next, *prev;
+};
+
+static inline void INIT_LIST_HEAD(struct list_head *list)
+{
+	list->next = list;
+	list->prev = list;
+}
+
+static inline int list_empty(const struct list_head *head)
+{
+	return head->next == head;
+}
+
+#define container_of(ptr, type, member) ({			\
+	typeof( ((type *)0)->member ) *__mptr = (ptr);		\
+	(type *)( (char *)__mptr - offsetof(type,member) );})
+
+#define list_entry(ptr, type, member)	\
+	container_of(ptr, type, member)
+
+#define list_first_entry(ptr, type, member) \
+	list_entry((ptr)->next, type, member)
+
+static inline void __list_add(struct list_head *new,
+			      struct list_head *prev,
+			      struct list_head *next)
+{
+	next->prev = new;
+	new->next = next;
+	new->prev = prev;
+	prev->next = new;
+}
+
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+	__list_add(new, head, head->next);
+}
+
+static inline void list_add_tail(struct list_head *new, struct list_head *head)
+{
+	__list_add(new, head->prev, head);
+}
+
+static inline void __list_del(struct list_head *prev, struct list_head *next)
+{
+	next->prev = prev;
+	prev->next = next;
+}
+
+static inline void list_del(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+	// entry->next = (void *) 0;
+	// entry->prev = (void *) 0;
+}
+
+static inline void __list_splice(const struct list_head *list,
+				 struct list_head *prev,
+				 struct list_head *next)
+{
+	struct list_head *first = list->next;
+	struct list_head *last = list->prev;
+
+	first->prev = prev;
+	prev->next = first;
+
+	last->next = next;
+	next->prev = last;
+}
+
+static inline void list_splice(const struct list_head *list,
+			       struct list_head *head)
+{
+	if (!list_empty(list))
+		__list_splice(list, head, head->next);
+}
+
+#define list_for_each_entry(pos, head, member)				\
+	for (pos = list_entry((head)->next, typeof(*pos), member);	\
+	     &pos->member != (head);					\
+	     pos = list_entry(pos->member.next, typeof(*pos), member))
+
+#define list_for_each_entry_safe(pos, n, head, member)			\
+	for (pos = list_entry((head)->next, typeof(*pos), member),	\
+	     	n = list_entry(pos->member.next, typeof(*pos), member);	\
+	     &pos->member != (head);					\
+	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
+
+#ifndef unlikely
+#define unlikely(x)		(!!(x) == 0)
+#endif
+
+extern void
+list_sort(void *priv, struct list_head *head,
+	  int (*cmp)(void *priv, struct list_head *a,
+		     struct list_head *b));
+#endif