Handle root offset and root table vtable invalidation (#7177)

* Handle invalid root offset

* Handle vtable offset invalidation

* Added script generator. Add more cases through vtable ref table size

* review responses

* vtable offset validation

* Moved padding insertion to the end. Tests invalid field lenghts

* table offsets validated. Added type after field

* validate string length

* add todo

* invalid vector length

* invalid structs

* general cleanup

* reworded invalid offsets

* example for vector of structs

* invalid vector of tables

* invalid vector of strings

* invalid vector of scalars

* vector of unions

* validate union type value

* invalid vector union type values

tests/annotated_binary/generate_annotations.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+#
+# Copyright 2021 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import platform
+import subprocess
+from pathlib import Path
+
+# Get the path where this script is located so we can invoke the script from
+# any directory and have the paths work correctly.
+script_path = Path(__file__).parent.resolve()
+
+# Get the root path as an absolute path, so all derived paths are absolute.
+root_path = script_path.parent.parent.absolute()
+
+# Get the location of the flatc executable, reading from the first command line
+# argument or defaulting to default names.
+flatc_exe = Path(
+    ("flatc" if not platform.system() == "Windows" else "flatc.exe")
+)
+
+# Find and assert flatc compiler is present.
+if root_path in flatc_exe.parents:
+    flatc_exe = flatc_exe.relative_to(root_path)
+flatc_path = Path(root_path, flatc_exe)
+assert flatc_path.exists(), "Cannot find the flatc compiler " + str(flatc_path)
+
+# Specify the other paths that will be referenced
+tests_path = Path(script_path, "tests")
+
+
+def flatc_annotate(schema, file, cwd=script_path):
+    cmd = [str(flatc_path), "--annotate", schema, file]
+    result = subprocess.run(cmd, cwd=str(cwd), check=True)
+
+
+test_files = [
+    "annotated_binary.bin",
+    "tests/invalid_root_offset.bin",
+    "tests/invalid_root_table_too_short.bin",
+    "tests/invalid_root_table_vtable_offset.bin",
+    "tests/invalid_string_length.bin",
+    "tests/invalid_string_length_cut_short.bin",
+    "tests/invalid_struct_array_field_cut_short.bin",
+    "tests/invalid_struct_field_cut_short.bin",
+    "tests/invalid_table_field_size.bin",
+    "tests/invalid_table_field_offset.bin",
+    "tests/invalid_union_type_value.bin",
+    "tests/invalid_vector_length_cut_short.bin",
+    "tests/invalid_vector_scalars_cut_short.bin",
+    "tests/invalid_vector_strings_cut_short.bin",
+    "tests/invalid_vector_structs_cut_short.bin",
+    "tests/invalid_vector_tables_cut_short.bin",
+    "tests/invalid_vector_unions_cut_short.bin",
+    "tests/invalid_vector_union_type_value.bin",
+    "tests/invalid_vtable_ref_table_size_short.bin",
+    "tests/invalid_vtable_ref_table_size.bin",
+    "tests/invalid_vtable_size_short.bin",
+    "tests/invalid_vtable_size.bin",
+    "tests/invalid_vtable_field_offset.bin",
+]
+
+for test_file in test_files:
+    flatc_annotate("annotated_binary.fbs", test_file)