Add modules and lsmod plugins (#364)

dissect/target/plugins/os/unix/linux/modules.py

@@ -0,0 +1,71 @@
+from dataclasses import dataclass
+from typing import Iterator
+
+from dissect.target.exceptions import UnsupportedPluginError
+from dissect.target.helpers.record import TargetRecordDescriptor
+from dissect.target.plugin import Plugin, export
+from dissect.target.target import Target
+
+ModuleRecord = TargetRecordDescriptor(
+    "linux/module",
+    [
+        ("string", "name"),
+        ("varint", "size"),
+        ("varint", "refcount"),
+        ("string[]", "used_by"),
+        ("path", "source"),
+    ],
+)
+
+
+@dataclass
+class Module:
+    path: str
+    name: str
+    size: int
+    refcnt: int
+    used_by: list[str]
+
+
+class ModulePlugin(Plugin):
+    def __init__(self, target: Target):
+        super().__init__(target)
+        self._module_base_path = self.target.fs.path("/sys/module")
+
+    def check_compatible(self) -> bool:
+        if not self._module_base_path.is_dir() or not next(self._module_base_path.iterdir(), None):
+            raise UnsupportedPluginError("No module paths found.")
+
+    def _iterate_modules(self) -> Iterator[Module]:
+        for module_path in self._module_base_path.iterdir():
+            if module_path.joinpath("initstate").exists():
+                holders = []
+                if (holders_path := module_path.joinpath("holders")).exists():
+                    holders = [item.name for item in holders_path.iterdir()]
+                yield Module(
+                    module_path,
+                    module_path.name,
+                    int(module_path.joinpath("coresize").read_text()),
+                    int(module_path.joinpath("refcnt").read_text()),
+                    holders,
+                )
+
+    @export(record=ModuleRecord)
+    def sysmodules(self) -> Iterator[ModuleRecord]:
+        """Return information about active kernel modules."""
+        for module in self._iterate_modules():
+            yield ModuleRecord(
+                name=module.name,
+                size=module.size,
+                refcount=module.refcnt,
+                used_by=module.used_by,
+                source=module.path,
+                _target=self.target,
+            )
+
+    @export(output="yield")
+    def lsmod(self) -> Iterator[str]:
+        """Return information about active kernel modules in lsmod format"""
+        yield f"{'Module ':<28} {'Size':<7}  Used by"
+        for module in self._iterate_modules():
+            yield f"{module.name:<28} {module.size:<7}  {module.refcnt} {','.join(module.used_by)}"

tests/data/plugins/os/unix/linux/modules/module/modulea/coresize

@@ -0,0 +1 @@
+1

tests/data/plugins/os/unix/linux/modules/module/modulea/holders/holdera

@@ -0,0 +1 @@
+.

tests/data/plugins/os/unix/linux/modules/module/modulea/initstate

@@ -0,0 +1 @@
+live

tests/data/plugins/os/unix/linux/modules/module/modulea/refcnt

@@ -0,0 +1 @@
+3

tests/data/plugins/os/unix/linux/modules/module/moduleb/coresize

@@ -0,0 +1 @@
+2

tests/data/plugins/os/unix/linux/modules/module/moduleb/holders/holdera

@@ -0,0 +1 @@
+.

tests/data/plugins/os/unix/linux/modules/module/moduleb/holders/holderb

@@ -0,0 +1 @@
+.

tests/data/plugins/os/unix/linux/modules/module/moduleb/initstate

@@ -0,0 +1 @@
+live

tests/data/plugins/os/unix/linux/modules/module/moduleb/refcnt

@@ -0,0 +1 @@
+4

tests/test_plugins_os_unix_linux_modules.py

@@ -0,0 +1,22 @@
+from dissect.target.filesystem import VirtualFilesystem
+from dissect.target.plugins.os.unix.linux.modules import ModulePlugin
+from dissect.target.target import Target
+
+from ._utils import absolute_path
+
+
+def test_modules_plugin(target_unix: Target, fs_unix: VirtualFilesystem) -> None:
+    test_folder = absolute_path("data/plugins/os/unix/linux/modules/module")
+    fs_unix.map_dir("/sys/module", test_folder)
+
+    target_unix.add_plugin(ModulePlugin)
+    results = sorted(list(target_unix.sysmodules()), key=lambda x: x.name)
+    assert len(results) == 2
+    assert results[0].name == "modulea"
+    assert results[0].size == 1
+    assert results[0].refcount == 3
+    assert results[0].used_by == ["holdera"]
+    assert results[1].name == "moduleb"
+    assert results[1].size == 2
+    assert results[1].refcount == 4
+    assert results[1].used_by == ["holdera", "holderb"]