1 files changed, 70 insertions, 0 deletions
diff --git a/contrib/dlz/modules/include/dlz_list.h b/contrib/dlz/modules/include/dlz_list.h
new file mode 100644
index 0000000..077ae89
--- /dev/null
+++ b/contrib/dlz/modules/include/dlz_list.h
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: ISC
+ *
+ * Permission to use, copy, modify, and distribute this software for any purpose
+ * with or without fee is hereby granted, provided that the above copyright
+ * notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#pragma once
+
+#define DLZ_LIST(type)             \
+	struct {                   \
+		type *head, *tail; \
+	}
+#define DLZ_LIST_INIT(list)         \
+	do {                        \
+		(list).head = NULL; \
+		(list).tail = NULL; \
+	} while (0)
+
+#define DLZ_LINK(type)             \
+	struct {                   \
+		type *prev, *next; \
+	}
+#define DLZ_LINK_INIT(elt, link)                 \
+	do {                                     \
+		(elt)->link.prev = (void *)(-1); \
+		(elt)->link.next = (void *)(-1); \
+	} while (0)
+
+#define DLZ_LIST_HEAD(list) ((list).head)
+#define DLZ_LIST_TAIL(list) ((list).tail)
+
+#define DLZ_LIST_APPEND(list, elt, link)                \
+	do {                                            \
+		if ((list).tail != NULL)                \
+			(list).tail->link.next = (elt); \
+		else                                    \
+			(list).head = (elt);            \
+		(elt)->link.prev = (list).tail;         \
+		(elt)->link.next = NULL;                \
+		(list).tail = (elt);                    \
+	} while (0)
+
+#define DLZ_LIST_PREV(elt, link) ((elt)->link.prev)
+#define DLZ_LIST_NEXT(elt, link) ((elt)->link.next)
+
+#define DLZ_LIST_UNLINK(list, elt, link)                                \
+	do {                                                            \
+		if ((elt)->link.next != NULL)                           \
+			(elt)->link.next->link.prev = (elt)->link.prev; \
+		else                                                    \
+			(list).tail = (elt)->link.prev;                 \
+		if ((elt)->link.prev != NULL)                           \
+			(elt)->link.prev->link.next = (elt)->link.next; \
+		else                                                    \
+			(list).head = (elt)->link.next;                 \
+		(elt)->link.prev = (void *)(-1);                        \
+		(elt)->link.next = (void *)(-1);                        \
+	} while (0)