1 files changed, 80 insertions, 0 deletions
diff --git a/lib/ns/include/ns/sortlist.h b/lib/ns/include/ns/sortlist.h
new file mode 100644
index 0000000..3333e9c
--- /dev/null
+++ b/lib/ns/include/ns/sortlist.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#pragma once
+
+/*! \file */
+
+#include <isc/types.h>
+
+#include <dns/acl.h>
+#include <dns/types.h>
+
+/*%
+ * Type for callback functions that rank addresses.
+ */
+typedef int (*dns_addressorderfunc_t)(const isc_netaddr_t *address,
+				      const void	  *arg);
+
+/*%
+ * Return value type for setup_sortlist.
+ */
+typedef enum {
+	NS_SORTLISTTYPE_NONE,
+	NS_SORTLISTTYPE_1ELEMENT,
+	NS_SORTLISTTYPE_2ELEMENT
+} ns_sortlisttype_t;
+
+ns_sortlisttype_t
+ns_sortlist_setup(dns_acl_t *acl, dns_aclenv_t *env, isc_netaddr_t *clientaddr,
+		  void **argp);
+/*%<
+ * Find the sortlist statement in 'acl' (for ACL environment 'env')
+ * that applies to 'clientaddr', if any.
+ *
+ * If a 1-element sortlist item applies, return NS_SORTLISTTYPE_1ELEMENT and
+ * make '*argp' point to the matching subelement.
+ *
+ * If a 2-element sortlist item applies, return NS_SORTLISTTYPE_2ELEMENT and
+ * make '*argp' point to ACL that forms the second element.
+ *
+ * If no sortlist item applies, return NS_SORTLISTTYPE_NONE and set '*argp'
+ * to NULL.
+ */
+
+int
+ns_sortlist_addrorder1(const isc_netaddr_t *addr, const void *arg);
+/*%<
+ * Find the sort order of 'addr' in 'arg', the matching element
+ * of a 1-element top-level sortlist statement.
+ */
+
+int
+ns_sortlist_addrorder2(const isc_netaddr_t *addr, const void *arg);
+/*%<
+ * Find the sort order of 'addr' in 'arg', a topology-like
+ * ACL forming the second element in a 2-element top-level
+ * sortlist statement.
+ */
+
+void
+ns_sortlist_byaddrsetup(dns_acl_t *sortlist_acl, dns_aclenv_t *env,
+			isc_netaddr_t	       *client_addr,
+			dns_addressorderfunc_t *orderp, void **argp);
+/*%<
+ * Find the sortlist statement in 'acl' that applies to 'clientaddr', if any.
+ * If a sortlist statement applies, return in '*orderp' a pointer to a function
+ * for ranking network addresses based on that sortlist statement, and in
+ * '*argp' an argument to pass to said function.  If no sortlist statement
+ * applies, set '*orderp' and '*argp' to NULL.
+ */