1 files changed, 61 insertions, 0 deletions
diff --git a/util/sbase/libutil/parseoffset.c b/util/sbase/libutil/parseoffset.c
new file mode 100644
index 00000000..362a7829
--- /dev/null
+++ b/util/sbase/libutil/parseoffset.c
@@ -0,0 +1,61 @@
+/* See LICENSE file for copyright and license details. */
+#include <ctype.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "../util.h"
+
+off_t
+parseoffset(const char *str)
+{
+	off_t res, scale = 1;
+	char *end;
+
+	/* strictly check what strtol() usually would let pass */
+	if (!str || !*str || isspace(*str) || *str == '+' || *str == '-') {
+		weprintf("parseoffset %s: invalid value\n", str);
+		return -1;
+	}
+
+	errno = 0;
+	res = strtol(str, &end, 0);
+	if (errno) {
+		weprintf("parseoffset %s: invalid value\n", str);
+		return -1;
+	}
+	if (res < 0) {
+		weprintf("parseoffset %s: negative value\n", str);
+		return -1;
+	}
+
+	/* suffix */
+	if (*end) {
+		switch (toupper((int)*end)) {
+		case 'B':
+			scale = 512L;
+			break;
+		case 'K':
+			scale = 1024L;
+			break;
+		case 'M':
+			scale = 1024L * 1024L;
+			break;
+		case 'G':
+			scale = 1024L * 1024L * 1024L;
+			break;
+		default:
+			weprintf("parseoffset %s: invalid suffix '%s'\n", str, end);
+			return -1;
+		}
+	}
+
+	/* prevent overflow */
+	if (res > (SSIZE_MAX / scale)) {
+		weprintf("parseoffset %s: out of range\n", str);
+		return -1;
+	}
+
+	return res * scale;
+}