[PATCH v7 05/12] binman: Add a way to check for a valid ELF file

[Simon Glass]

Add a function which checks whether data is in ELF format or not. This
will be used by binman to check this for entries.

Signed-off-by: Simon Glass <sjg at chromium.org>
---

(no changes since v1)

 tools/binman/elf.py      | 16 ++++++++++++++++
 tools/binman/elf_test.py | 10 ++++++++++
 2 files changed, 26 insertions(+)

diff --git a/tools/binman/elf.py b/tools/binman/elf.py
index fe50bf542c3..2f4b7d1a08e 100644
--- a/tools/binman/elf.py
+++ b/tools/binman/elf.py
@@ -21,6 +21,7 @@ ELF_TOOLS = True
 try:
     from elftools.elf.elffile import ELFFile
     from elftools.elf.elffile import ELFError
+    import elftools
     from elftools.elf.sections import SymbolTableSection
 except:  # pragma: no cover
     ELF_TOOLS = False
@@ -518,3 +519,18 @@ def read_loadable_segments(data):
             rend = start + segment['p_filesz']
             segments.append((i, segment['p_paddr'], data[start:rend]))
     return segments, entry
+
+def is_valid(data):
+    """Check if some binary data is a valid ELF file
+
+    Args:
+        data (bytes): Bytes to check
+
+    Returns:
+        bool: True if a valid Elf file, False if not
+    """
+    try:
+        DecodeElf(data, 0)
+        return True
+    except elftools.common.exceptions.ELFError:
+        return False
diff --git a/tools/binman/elf_test.py b/tools/binman/elf_test.py
index 75b867c2be8..082a3e1d28c 100644
--- a/tools/binman/elf_test.py
+++ b/tools/binman/elf_test.py
@@ -348,6 +348,16 @@ class TestElf(unittest.TestCase):
         finally:
             elf.ELF_TOOLS = old_val
 
+    def test_is_valid(self):
+        """Test is_valid()"""
+        self.assertEqual(False, elf.is_valid(b''))
+        self.assertEqual(False, elf.is_valid(b'1234'))
+
+        fname = self.ElfTestFile('elf_sections')
+        data = tools.read_file(fname)
+        self.assertEqual(True, elf.is_valid(data))
+        self.assertEqual(False, elf.is_valid(data[4:]))
+
 
 if __name__ == '__main__':
     unittest.main()
-- 
2.39.0.314.g84b9a713c41-goog