1 files changed, 135 insertions, 0 deletions
diff --git a/lib/isc/portset.c b/lib/isc/portset.c
new file mode 100644
index 0000000..52b96f5
--- /dev/null
+++ b/lib/isc/portset.c
@@ -0,0 +1,135 @@
+/*
+ * 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.
+ */
+
+/*! \file */
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+#include <isc/mem.h>
+#include <isc/portset.h>
+#include <isc/string.h>
+#include <isc/types.h>
+#include <isc/util.h>
+
+#define ISC_PORTSET_BUFSIZE (65536 / (sizeof(uint32_t) * 8))
+
+/*%
+ * Internal representation of portset.  It's an array of 32-bit integers, each
+ * bit corresponding to a single port in the ascending order.  For example,
+ * the second most significant bit of buf[0] corresponds to port 1.
+ */
+struct isc_portset {
+	unsigned int nports; /*%< number of ports in the set */
+	uint32_t buf[ISC_PORTSET_BUFSIZE];
+};
+
+static bool
+portset_isset(isc_portset_t *portset, in_port_t port) {
+	return ((portset->buf[port >> 5] & ((uint32_t)1 << (port & 31))) != 0);
+}
+
+static void
+portset_add(isc_portset_t *portset, in_port_t port) {
+	if (!portset_isset(portset, port)) {
+		portset->nports++;
+		portset->buf[port >> 5] |= ((uint32_t)1 << (port & 31));
+	}
+}
+
+static void
+portset_remove(isc_portset_t *portset, in_port_t port) {
+	if (portset_isset(portset, port)) {
+		portset->nports--;
+		portset->buf[port >> 5] &= ~((uint32_t)1 << (port & 31));
+	}
+}
+
+isc_result_t
+isc_portset_create(isc_mem_t *mctx, isc_portset_t **portsetp) {
+	isc_portset_t *portset;
+
+	REQUIRE(portsetp != NULL && *portsetp == NULL);
+
+	portset = isc_mem_get(mctx, sizeof(*portset));
+
+	/* Make the set 'empty' by default */
+	memset(portset, 0, sizeof(*portset));
+	*portsetp = portset;
+
+	return (ISC_R_SUCCESS);
+}
+
+void
+isc_portset_destroy(isc_mem_t *mctx, isc_portset_t **portsetp) {
+	isc_portset_t *portset;
+
+	REQUIRE(portsetp != NULL);
+	portset = *portsetp;
+
+	isc_mem_put(mctx, portset, sizeof(*portset));
+}
+
+bool
+isc_portset_isset(isc_portset_t *portset, in_port_t port) {
+	REQUIRE(portset != NULL);
+
+	return (portset_isset(portset, port));
+}
+
+unsigned int
+isc_portset_nports(isc_portset_t *portset) {
+	REQUIRE(portset != NULL);
+
+	return (portset->nports);
+}
+
+void
+isc_portset_add(isc_portset_t *portset, in_port_t port) {
+	REQUIRE(portset != NULL);
+
+	portset_add(portset, port);
+}
+
+void
+isc_portset_remove(isc_portset_t *portset, in_port_t port) {
+	portset_remove(portset, port);
+}
+
+void
+isc_portset_addrange(isc_portset_t *portset, in_port_t port_lo,
+		     in_port_t port_hi) {
+	in_port_t p;
+
+	REQUIRE(portset != NULL);
+	REQUIRE(port_lo <= port_hi);
+
+	p = port_lo;
+	do {
+		portset_add(portset, p);
+	} while (p++ < port_hi);
+}
+
+void
+isc_portset_removerange(isc_portset_t *portset, in_port_t port_lo,
+			in_port_t port_hi) {
+	in_port_t p;
+
+	REQUIRE(portset != NULL);
+	REQUIRE(port_lo <= port_hi);
+
+	p = port_lo;
+	do {
+		portset_remove(portset, p);
+	} while (p++ < port_hi);
+}