devices: parse files in the devices subsystem

Also, a test!

Signed-off-by: Levente Kurusa <lkurusa@acm.org>

tests/devices.rs

@@ -0,0 +1,45 @@
+//! Integration tests about the devices subsystem
+
+extern crate cgroups;
+use cgroups::{Cgroup, DeviceResource};
+use cgroups::devices::{DevicesController, DevicePermissions, DeviceType};
+
+#[test]
+fn test_devices_parsing() {
+    let hier = cgroups::hierarchies::V1::new();
+    let cg = Cgroup::new(&hier, String::from("test_devices_parsing"));
+    {
+        let devices: &DevicesController = cg.controller_of().unwrap();
+
+        // Deny access to all devices first
+        devices.deny_device(DeviceType::All, -1, -1, &vec![DevicePermissions::Read, DevicePermissions::Write, DevicePermissions::MkNod]);
+        // Acquire the list of allowed devices after we denied all
+        let allowed_devices = devices.allowed_devices();
+        // Verify that there are no devices that we can access.
+        assert!(allowed_devices.is_ok());
+        assert_eq!(allowed_devices.unwrap(), Vec::new());
+
+        // Now add mknod access to /dev/null device
+        devices.allow_device(DeviceType::Char, 1, 3, &vec![DevicePermissions::MkNod]);
+        let allowed_devices = devices.allowed_devices();
+        assert!(allowed_devices.is_ok());
+        let allowed_devices = allowed_devices.unwrap();
+        assert_eq!(allowed_devices.len(), 1);
+        assert_eq!(allowed_devices[0], DeviceResource {
+            allow: true,
+            devtype: DeviceType::Char,
+            major: 1,
+            minor: 3,
+            access: vec![DevicePermissions::MkNod],
+        });
+
+        // Now deny, this device explicitly.
+        devices.deny_device(DeviceType::Char, 1, 3, &DevicePermissions::all());
+        // Finally, check that.
+        let allowed_devices = devices.allowed_devices();
+        // Verify that there are no devices that we can access.
+        assert!(allowed_devices.is_ok());
+        assert_eq!(allowed_devices.unwrap(), Vec::new());
+    }
+    cg.delete();
+}