Fstab accepts non-absolute path as source

Author: gronke

libioc/Config/Jail/File/Fstab.py

@@ -76,10 +76,16 @@ def __setitem__(
         value: typing.Union[str, libioc.Types.AbsolutePath]
     ) -> None:
         """Set an item of the FstabLine."""
-        if (key == "source") or (key == "destination"):
+        _type = None
+        if key == "source":
+            _type = libioc.Types.Path
+        elif key == "destination":
+            _type = libioc.Types.AbsolutePath
+
+        if _type is not None:  # source or destination
             if isinstance(value, str) is True:
-                absolute_path = libioc.Types.AbsolutePath(value)
-            elif isinstance(value, libioc.Types.AbsolutePath) is True:
+                absolute_path = _type(value)
+            elif isinstance(value, _type) is True:
                 absolute_path = value
             else:
                 raise ValueError("String or AbsolutePath expected")
@@ -287,7 +293,7 @@ def parse_lines(
                 ])
 
             new_line = FstabLine({
-                "source": libioc.Types.AbsolutePath(source),
+                "source": libioc.Types.Path(source),
                 "destination": libioc.Types.AbsolutePath(destination),
                 "type": fragments[2],
                 "options": fragments[3],

libioc/Types.py

@@ -27,20 +27,45 @@
 import re
 
 
-class AbsolutePath(str):
+class Path(str):
     """Wrapper Type for ensuring a `str` matches a Unix Path."""
 
-    unix_path = re.compile(r"/([^/\0]+/*)+")
+    blacklist = re.compile(
+        r"(\/\/)|(\/\.\.)|(\.\.\/)|(\n)|(\r)|(^\.+$)",
+        re.MULTILINE
+    )
 
     def __init__(
-            self,
-            sequence: str
+        self,
+        sequence: str
     ) -> None:
-        if self.unix_path.fullmatch(sequence) is None:
-            raise TypeError(f"Invalid value for AbsolutePath: {sequence}")
+        if isinstance(sequence, str) is False:
+            raise TypeError("Path must be a string")
+
+        if len(self.blacklist.findall(sequence)) > 0:
+            raise TypeError(f"Illegal path: {sequence}")
+
         self = sequence  # type: ignore
 
 
+class AbsolutePath(Path):
+    """Wrapper Type for ensuring a `str` matches an absolute Unix Path."""
+
+    def __init__(
+        self,
+        sequence: str
+    ) -> None:
+        if isinstance(sequence, str) is False:
+            raise TypeError("AbsolutePath must be a string or Path")
+
+        if str(sequence).startswith("/") is False:
+            raise TypeError(
+                f"Expected AbsolutePath to begin with /, but got: {sequence}"
+            )
+
+        super().__init__(sequence)
+
+
 class UserInput:
     """Any kind of user input data."""