Refactor Linux kernel module metadata as a file scan plugin

Signed-off-by: OctavioValdiviaMendoza <octavio.valdiviamendoza@sjsu.edu>

Author: OctavioValdiviaMendoza

CHANGELOG.rst

@@ -8,7 +8,7 @@ Next release
   ``licensedcode-data``.
   https://github.com/aboutcode-org/scancode-toolkit/pull/5056
 
-- Add a package data handler for compiled Linux Kernel Module (``.ko``)
+- Add a file-level scan plugin for compiled Linux Kernel Module (``.ko``)
   files that extracts metadata from the ELF ``.modinfo`` section.
 
 v33.0.0rc1 - 2026-05-14

pyproject-scancode-toolkit.toml

@@ -267,6 +267,7 @@ facet = "summarycode.facet:AddFacet"
 # module for details and doc.
 [project.entry-points.scancode_scan]
 info = "scancode.plugin_info:InfoScanner"
+lkm = "scancode.plugin_lkm:LinuxKernelModuleScanner"
 licenses = "licensedcode.plugin_license:LicenseScanner"
 copyrights = "cluecode.plugin_copyright:CopyrightScanner"
 packages = "packagedcode.plugin_package:PackageScanner"

pyproject.toml

@@ -272,6 +272,7 @@ facet = "summarycode.facet:AddFacet"
 # module for details and doc.
 [project.entry-points.scancode_scan]
 info = "scancode.plugin_info:InfoScanner"
+lkm = "scancode.plugin_lkm:LinuxKernelModuleScanner"
 licenses = "licensedcode.plugin_license:LicenseScanner"
 copyrights = "cluecode.plugin_copyright:CopyrightScanner"
 packages = "packagedcode.plugin_package:PackageScanner"

src/packagedcode/__init__.py

@@ -26,7 +26,6 @@
 from packagedcode import godeps
 from packagedcode import golang
 from packagedcode import haxe
-from packagedcode import lkm
 from packagedcode import maven
 from packagedcode import misc
 from packagedcode import npm
@@ -234,8 +233,6 @@
     debian.DebianInstalledMd5sumFilelistHandler,
     debian.DebianInstalledStatusDatabaseHandler,
 
-    lkm.LinuxKernelModuleHandler,
-
     rpm.RpmLicenseFilesHandler,
     rpm.RpmMarinerContainerManifestHandler,
 ]

src/packagedcode/lkm.py

@@ -0,0 +1,130 @@
+#
+# Copyright (c) nexB Inc. and others. All rights reserved.
+# ScanCode is a trademark of nexB Inc.
+# SPDX-License-Identifier: Apache-2.0
+# See http://www.apache.org/licenses/LICENSE-2.0 for the license text.
+# See https://github.com/nexB/scancode-toolkit for support or download.
+# See https://aboutcode.org for more information about nexB OSS projects.
+#
+
+from typing import Dict
+from typing import List
+
+import attr
+
+from commoncode.cliutils import OTHER_SCAN_GROUP
+from commoncode.cliutils import PluggableCommandLineOption
+from elftools.common.exceptions import ELFError
+from elftools.elf.elffile import ELFFile
+from plugincode.scan import ScanPlugin
+from plugincode.scan import scan_impl
+
+
+@scan_impl
+class LinuxKernelModuleScanner(ScanPlugin):
+    """
+    Scan Linux kernel module files for metadata stored in their ELF
+    '.modinfo' section.
+    """
+
+    resource_attributes = dict(
+        linux_kernel_module=attr.ib(default=None, repr=False),
+    )
+
+    run_order = 9
+    sort_order = 9
+
+    options = [
+        PluggableCommandLineOption(
+            ('--lkm',),
+            is_flag=True,
+            default=False,
+            help='Scan Linux kernel module files for .modinfo metadata.',
+            help_group=OTHER_SCAN_GROUP,
+        )
+    ]
+
+    def is_enabled(self, lkm, **kwargs):
+        return lkm
+
+    def get_scanner(self, **kwargs):
+        return scan_linux_kernel_module
+
+
+def scan_linux_kernel_module(location, **kwargs):
+    """
+    Return a mapping of Linux kernel module metadata found in the '.ko' file
+    at 'location'. Return an empty mapping for other files and for files that
+    do not contain usable '.modinfo' metadata.
+    """
+    if not location.lower().endswith('.ko'):
+        return {}
+
+    metadata = extract_modinfo(location)
+    if not metadata:
+        return {}
+
+    # The .modinfo "depends" value is a comma-separated list of required
+    # kernel module names, not a list of package-management dependencies.
+    metadata['depends'] = get_dependency_names(metadata)
+
+    return dict(linux_kernel_module=metadata)
+
+
+def extract_modinfo(location: str) -> Dict[str, List[str]]:
+    """
+    Extract '.modinfo' metadata from the Linux kernel module file at 'location'.
+
+    Return '.modinfo' metadata as a mapping of keys to lists of values.
+
+    Multiple values are preserved because fields such as 'author', 'alias',
+    and 'firmware' may occur more than once.
+    """
+    metadata: Dict[str, List[str]] = {}
+
+    try:
+        with open(location, 'rb') as module_file:
+            elf_file = ELFFile(module_file)
+            modinfo_section = elf_file.get_section_by_name('.modinfo')
+            if modinfo_section is None:
+                return {}
+
+            raw_bytes = modinfo_section.data()
+
+    except (ELFError, OSError):
+        return {}
+
+    # Entries in .modinfo are NUL-terminated key=value strings.
+    for raw_entry in raw_bytes.split(b'\x00'):
+        if not raw_entry:
+            continue
+
+        entry = raw_entry.decode('utf-8', errors='replace')
+        if '=' not in entry:
+            continue
+
+        key, value = entry.split('=', 1)
+        if not key:
+            continue
+
+        metadata.setdefault(key, []).append(value)
+
+    return metadata
+
+
+def get_dependency_names(metadata: Dict[str, List[str]]) -> List[str]:
+    """
+    Returns a list of strings, each being a kernel module name
+    Normalized fields to a list of strings derived from the '.modinfo' metadata. The 'depends' field is a
+    comma-separated list of required kernel module names 
+    """
+    dependency_names = []
+
+    for depends_entry in metadata.get('depends', []):
+        dependency_names.extend(
+            dependency.strip()
+            for dependency in depends_entry.split(',')
+            if dependency.strip()
+        )
+
+    return dependency_names