1 files changed, 60 insertions, 0 deletions
diff --git a/lib/fstree/canonicalize_name.c b/lib/fstree/canonicalize_name.c
new file mode 100644
index 0000000..f35307f
--- /dev/null
+++ b/lib/fstree/canonicalize_name.c
@@ -0,0 +1,60 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * canonicalize_name.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+#include "fstree.h"
+
+static void normalize_slashes(char *filename)
+{
+	char *dst = filename, *src = filename;
+
+	while (*src == '/' || *src == '\\')
+		++src;
+
+	while (*src != '\0') {
+		if (*src == '/' || *src == '\\') {
+			while (*src == '/' || *src == '\\')
+				++src;
+			if (*src == '\0')
+				break;
+			*(dst++) = '/';
+		} else {
+			*(dst++) = *(src++);
+		}
+	}
+
+	*dst = '\0';
+}
+
+int canonicalize_name(char *filename)
+{
+	char *dst = filename, *src = filename;
+
+	normalize_slashes(filename);
+
+	while (*src != '\0') {
+		if (src[0] == '.') {
+			if (src[1] == '\0')
+				break;
+			if (src[1] == '/') {
+				src += 2;
+				continue;
+			}
+			if (src[1] == '.' && (src[2] == '/' || src[2] == '\0'))
+				return -1;
+		}
+
+		while (*src != '\0' && *src != '/')
+			*(dst++) = *(src++);
+
+		if (*src == '/')
+			*(dst++) = *(src++);
+	}
+
+	*dst = '\0';
+	normalize_slashes(filename);
+	return 0;
+}