1 files changed, 45 insertions, 0 deletions
diff --git a/src/timesync/timesyncd-ntp-message.h b/src/timesync/timesyncd-ntp-message.h
new file mode 100644
index 0000000..14fba6d
--- /dev/null
+++ b/src/timesync/timesyncd-ntp-message.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include "sparse-endian.h"
+
+/* NTP protocol, packet header */
+#define NTP_LEAP_PLUSSEC                1
+#define NTP_LEAP_MINUSSEC               2
+#define NTP_LEAP_NOTINSYNC              3
+#define NTP_MODE_CLIENT                 3
+#define NTP_MODE_SERVER                 4
+#define NTP_FIELD_LEAP(f)               (((f) >> 6) & 3)
+#define NTP_FIELD_VERSION(f)            (((f) >> 3) & 7)
+#define NTP_FIELD_MODE(f)               ((f) & 7)
+#define NTP_FIELD(l, v, m)              (((l) << 6) | ((v) << 3) | (m))
+
+/*
+ * "NTP timestamps are represented as a 64-bit unsigned fixed-point number,
+ * in seconds relative to 0h on 1 January 1900."
+ */
+#define OFFSET_1900_1970        UINT64_C(2208988800)
+
+struct ntp_ts {
+        be32_t sec;
+        be32_t frac;
+} _packed_;
+
+struct ntp_ts_short {
+        be16_t sec;
+        be16_t frac;
+} _packed_;
+
+struct ntp_msg {
+        uint8_t field;
+        uint8_t stratum;
+        int8_t poll;
+        int8_t precision;
+        struct ntp_ts_short root_delay;
+        struct ntp_ts_short root_dispersion;
+        char refid[4];
+        struct ntp_ts reference_time;
+        struct ntp_ts origin_time;
+        struct ntp_ts recv_time;
+        struct ntp_ts trans_time;
+} _packed_;