Improve Linux OS detection

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

@@ -26,11 +26,10 @@ def detect(cls, target: Target) -> Optional[Filesystem]:
                 fs.exists("/var")
                 and fs.exists("/etc")
                 and fs.exists("/opt")
-                or (fs.exists("/sys") or fs.exists("/proc"))
-                and not fs.exists("/Library")
+                or (fs.exists("/proc") or fs.exists("/sys"))
             ):
-                return fs
-        return None
+                if not (fs.exists("/windows") or fs.exists("/$MFT")) and not fs.exists("/Library"):
+                    return fs
 
     @export(property=True)
     def ips(self) -> list[str]:

tests/conftest.py

@@ -126,6 +126,12 @@ def fs_suse() -> Iterator[VirtualFilesystem]:
     yield fs
 
 
+@pytest.fixture
+def fs_linux_sys(fs_linux: VirtualFilesystem) -> Iterator[VirtualFilesystem]:
+    fs_linux.makedirs("sys")
+    yield fs_linux
+
+
 @pytest.fixture
 def fs_linux_proc(fs_linux: VirtualFilesystem) -> Iterator[VirtualFilesystem]:
     fs = fs_linux

tests/plugins/os/unix/linux/test__os.py

@@ -0,0 +1,30 @@
+import pathlib
+from typing import Iterator
+
+import pytest
+
+from dissect.target import Target
+from dissect.target.filesystem import VirtualFilesystem
+from dissect.target.plugins.os.unix.linux._os import LinuxPlugin
+from tests.conftest import make_os_target
+
+
+@pytest.fixture
+def target_linux_proc_sys(tmp_path: pathlib.Path) -> Iterator[Target]:
+    root_fs = VirtualFilesystem()
+    root_fs.makedirs("/proc")
+    root_fs.makedirs("/sys")
+    target_linux_proc_sys = make_os_target(tmp_path, LinuxPlugin, root_fs)
+
+    yield target_linux_proc_sys
+
+
+def test_linux_os(target_linux: Target) -> None:
+    target_linux.add_plugin(LinuxPlugin)
+
+    assert target_linux.os == "linux"
+
+
+def test_linux_os_proc_sys(target_linux_proc_sys: Target) -> None:
+    assert target_linux_proc_sys._os_plugin.detect(target_linux_proc_sys) is not None
+    assert target_linux_proc_sys.os == "linux"

tests/plugins/os/windows/test__os.py

@@ -1,11 +1,15 @@
-from typing import Any, Optional
+import pathlib
+from typing import Any, Iterator, Optional
 
 import pytest
 
+from dissect.target.filesystem import Filesystem
 from dissect.target.helpers.regutil import VirtualKey, VirtualValue
+from dissect.target.plugins.os.unix.linux._os import LinuxPlugin
 from dissect.target.plugins.os.windows._os import WindowsPlugin
 from dissect.target.plugins.os.windows.registry import RegistryPlugin
 from dissect.target.target import Target
+from tests.conftest import make_mock_target
 
 
 def current_version_key() -> str:
@@ -31,6 +35,17 @@ def win_plugin(version_target: Target):
     return WindowsPlugin(version_target)
 
 
+@pytest.fixture
+def target_win_linux_folders(tmp_path: pathlib.Path, fs_win: Filesystem, fs_linux_sys: Filesystem) -> Iterator[Target]:
+    root_fs = fs_win
+    root_fs.mount("/", fs_linux_sys)
+
+    mock_target = next(make_mock_target(tmp_path))
+    mock_target.filesystems.add(root_fs)
+
+    yield mock_target
+
+
 def map_version_value(target: Target, name: Optional[str], value: Any):
     if name is not None:
         hive = target.registry._root
@@ -235,3 +250,11 @@ def test_windowsplugin_version(
     result = win_plugin.version
 
     assert_value(result, value)
+
+
+def test_windows_os_detection_with_linux_folders(target_win_linux_folders: Target) -> None:
+    fs_linux = LinuxPlugin.detect(target_win_linux_folders)
+    fs_windows = WindowsPlugin.detect(target_win_linux_folders)
+
+    assert fs_linux is None
+    assert fs_windows is not None