1 files changed, 45 insertions, 0 deletions
diff --git a/src/shared/udev-util.c b/src/shared/udev-util.c
index 17b9ed137b..d03e4bbe6f 100644
--- a/src/shared/udev-util.c
+++ b/src/shared/udev-util.c
@@ -5,6 +5,7 @@
 #include <unistd.h>
 
 #include "alloc-util.h"
+#include "device-nodes.h"
 #include "device-util.h"
 #include "env-file.h"
 #include "escape.h"
@@ -426,3 +427,47 @@ size_t udev_replace_whitespace(const char *str, char *to, size_t len) {
         to[j] = '\0';
         return j;
 }
+
+size_t udev_replace_chars(char *str, const char *allow) {
+        size_t i = 0, replaced = 0;
+
+        assert(str);
+
+        /* allow chars in allow list, plain ascii, hex-escaping and valid utf8. */
+
+        while (str[i] != '\0') {
+                int len;
+
+                if (allow_listed_char_for_devnode(str[i], allow)) {
+                        i++;
+                        continue;
+                }
+
+                /* accept hex encoding */
+                if (str[i] == '\\' && str[i+1] == 'x') {
+                        i += 2;
+                        continue;
+                }
+
+                /* accept valid utf8 */
+                len = utf8_encoded_valid_unichar(str + i, (size_t) -1);
+                if (len > 1) {
+                        i += len;
+                        continue;
+                }
+
+                /* if space is allowed, replace whitespace with ordinary space */
+                if (isspace(str[i]) && allow && strchr(allow, ' ')) {
+                        str[i] = ' ';
+                        i++;
+                        replaced++;
+                        continue;
+                }
+
+                /* everything else is replaced with '_' */
+                str[i] = '_';
+                i++;
+                replaced++;
+        }
+        return replaced;
+}