1 files changed, 123 insertions, 0 deletions
diff --git a/lib/utils_math.c b/lib/utils_math.c
new file mode 100644
index 0000000..9ef3dd6
--- /dev/null
+++ b/lib/utils_math.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <asm/types.h>
+
+#include "utils.h"
+
+/* See http://physics.nist.gov/cuu/Units/binary.html */
+static const struct rate_suffix {
+	const char *name;
+	double scale;
+} suffixes[] = {
+	{ "bit",	1. },
+	{ "Kibit",	1024. },
+	{ "kbit",	1000. },
+	{ "mibit",	1024.*1024. },
+	{ "mbit",	1000000. },
+	{ "gibit",	1024.*1024.*1024. },
+	{ "gbit",	1000000000. },
+	{ "tibit",	1024.*1024.*1024.*1024. },
+	{ "tbit",	1000000000000. },
+	{ "Bps",	8. },
+	{ "KiBps",	8.*1024. },
+	{ "KBps",	8000. },
+	{ "MiBps",	8.*1024*1024. },
+	{ "MBps",	8000000. },
+	{ "GiBps",	8.*1024.*1024.*1024. },
+	{ "GBps",	8000000000. },
+	{ "TiBps",	8.*1024.*1024.*1024.*1024. },
+	{ "TBps",	8000000000000. },
+	{ NULL }
+};
+
+int get_rate(unsigned int *rate, const char *str)
+{
+	char *p;
+	double bps = strtod(str, &p);
+	const struct rate_suffix *s;
+
+	if (p == str)
+		return -1;
+
+	for (s = suffixes; s->name; ++s) {
+		if (strcasecmp(s->name, p) == 0) {
+			bps *= s->scale;
+			p += strlen(p);
+			break;
+		}
+	}
+
+	if (*p)
+		return -1; /* unknown suffix */
+
+	bps /= 8; /* -> bytes per second */
+	*rate = bps;
+	/* detect if an overflow happened */
+	if (*rate != floor(bps))
+		return -1;
+	return 0;
+}
+
+int get_rate64(__u64 *rate, const char *str)
+{
+	char *p;
+	double bps = strtod(str, &p);
+	const struct rate_suffix *s;
+
+	if (p == str)
+		return -1;
+
+	for (s = suffixes; s->name; ++s) {
+		if (strcasecmp(s->name, p) == 0) {
+			bps *= s->scale;
+			p += strlen(p);
+			break;
+		}
+	}
+
+	if (*p)
+		return -1; /* unknown suffix */
+
+	bps /= 8; /* -> bytes per second */
+	*rate = bps;
+	return 0;
+}
+
+int get_size(unsigned int *size, const char *str)
+{
+	double sz;
+	char *p;
+
+	sz = strtod(str, &p);
+	if (p == str)
+		return -1;
+
+	if (*p) {
+		if (strcasecmp(p, "kb") == 0 || strcasecmp(p, "k") == 0)
+			sz *= 1024;
+		else if (strcasecmp(p, "gb") == 0 || strcasecmp(p, "g") == 0)
+			sz *= 1024*1024*1024;
+		else if (strcasecmp(p, "gbit") == 0)
+			sz *= 1024*1024*1024/8;
+		else if (strcasecmp(p, "mb") == 0 || strcasecmp(p, "m") == 0)
+			sz *= 1024*1024;
+		else if (strcasecmp(p, "mbit") == 0)
+			sz *= 1024*1024/8;
+		else if (strcasecmp(p, "kbit") == 0)
+			sz *= 1024/8;
+		else if (strcasecmp(p, "b") != 0)
+			return -1;
+	}
+
+	*size = sz;
+
+	/* detect if an overflow happened */
+	if (*size != floor(sz))
+		return -1;
+
+	return 0;
+}