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-rw-r--r--src/timesync/timesyncd-ntp-message.h45
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..76ed9ec
--- /dev/null
+++ b/src/timesync/timesyncd-ntp-message.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#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_;