1 files changed, 75 insertions, 0 deletions
diff --git a/src/time.c b/src/time.c
new file mode 100644
index 0000000..fd0e4e3
--- /dev/null
+++ b/src/time.c
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2021 Yubico AB. All rights reserved.
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file.
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <errno.h>
+#include "fido.h"
+
+static int
+timespec_to_ms(const struct timespec *ts)
+{
+	int64_t x, y;
+
+	if (ts->tv_sec < 0 || ts->tv_nsec < 0 ||
+	    ts->tv_nsec >= 1000000000LL)
+		return -1;
+
+	if ((uint64_t)ts->tv_sec >= INT64_MAX / 1000LL)
+		return -1;
+
+	x = ts->tv_sec * 1000LL;
+	y = ts->tv_nsec / 1000000LL;
+
+	if (INT64_MAX - x < y || x + y > INT_MAX)
+		return -1;
+
+	return (int)(x + y);
+}
+
+int
+fido_time_now(struct timespec *ts_now)
+{
+	if (clock_gettime(CLOCK_MONOTONIC, ts_now) != 0) {
+		fido_log_error(errno, "%s: clock_gettime", __func__);
+		return -1;
+	}
+
+	return 0;
+}
+
+int
+fido_time_delta(const struct timespec *ts_start, int *ms_remain)
+{
+	struct timespec ts_end, ts_delta;
+	int ms;
+
+	if (*ms_remain < 0)
+		return 0;
+
+	if (clock_gettime(CLOCK_MONOTONIC, &ts_end) != 0) {
+		fido_log_error(errno, "%s: clock_gettime", __func__);
+		return -1;
+	}
+
+	if (timespeccmp(&ts_end, ts_start, <)) {
+		fido_log_debug("%s: timespeccmp", __func__);
+		return -1;
+	}
+
+	timespecsub(&ts_end, ts_start, &ts_delta);
+
+	if ((ms = timespec_to_ms(&ts_delta)) < 0) {
+		fido_log_debug("%s: timespec_to_ms", __func__);
+		return -1;
+	}
+
+	if (ms > *ms_remain)
+		ms = *ms_remain;
+
+	*ms_remain -= ms;
+
+	return 0;
+}