diff --git a/src/lib/util/perm.c b/src/lib/util/perm.c
index e8ea254e769c..c2cb38b91c3c 100644
--- a/src/lib/util/perm.c
+++ b/src/lib/util/perm.c
@@ -59,6 +59,24 @@ char const *fr_perm_mode_to_oct(char out[static 5], mode_t mode)
 	return out;
 }
 
+int fr_perm_mode_from_str(mode_t *out, char const *str)
+{
+	if (*str == '0') {
+		unsigned long mode;
+		char *end = NULL;
+
+		mode = strtoul(str, &end, 7);
+		if (*end || (mode == ULONG_MAX)) {
+			return -1;
+		}
+
+		*out = mode;
+		return 0;
+	}
+
+	return -1;
+}
+
 /** Resolve a uid to a passwd entry
  *
  * Resolves a uid to a passwd entry. The memory to hold the
diff --git a/src/lib/util/perm.h b/src/lib/util/perm.h
index 057e7133afe4..474db39bb215 100644
--- a/src/lib/util/perm.h
+++ b/src/lib/util/perm.h
@@ -38,6 +38,8 @@ char const	*fr_perm_mode_to_str(char out[static 10], mode_t mode);
 
 char const 	*fr_perm_mode_to_oct(char out[static 5], mode_t mode);
 
+int		fr_perm_mode_from_str(mode_t *out, char const *str) CC_HINT(nonnull);
+
 int		fr_perm_getpwuid(TALLOC_CTX *ctx, struct passwd **out, uid_t uid) CC_HINT(nonnull(2));
 
 int		fr_perm_getpwnam(TALLOC_CTX *ctx, struct passwd **out, char const *name) CC_HINT(nonnull(2,3));