1 files changed, 31 insertions, 0 deletions
diff --git a/src/libsystemd-network/ndisc-protocol.h b/src/libsystemd-network/ndisc-protocol.h
new file mode 100644
index 0000000..8e403e3
--- /dev/null
+++ b/src/libsystemd-network/ndisc-protocol.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "time-util.h"
+
+/* RFC 8781: PREF64 or (NAT64 prefix) */
+#define PREF64_SCALED_LIFETIME_MASK      0xfff8
+#define PREF64_PLC_MASK                  0x0007
+#define PREF64_MAX_LIFETIME_USEC         (65528 * USEC_PER_SEC)
+
+typedef enum PrefixLengthCode {
+        PREFIX_LENGTH_CODE_96,
+        PREFIX_LENGTH_CODE_64,
+        PREFIX_LENGTH_CODE_56,
+        PREFIX_LENGTH_CODE_48,
+        PREFIX_LENGTH_CODE_40,
+        PREFIX_LENGTH_CODE_32,
+        _PREFIX_LENGTH_CODE_MAX,
+        _PREFIX_LENGTH_CODE_INVALID = -EINVAL,
+} PrefixLengthCode;
+
+/* rfc8781: section 4 - Scaled Lifetime: 13-bit unsigned integer. PREFIX_LEN (Prefix Length Code): 3-bit unsigned integer */
+struct nd_opt_prefix64_info {
+        uint8_t type;
+        uint8_t length;
+        uint16_t lifetime_and_plc;
+        uint8_t prefix[12];
+} __attribute__((__packed__));
+
+int pref64_plc_to_prefix_length(uint16_t plc, uint8_t *ret);
+int pref64_prefix_length_to_plc(uint8_t prefixlen, uint8_t *ret);