fde,devicestate: add new fde.CheckFeatures() and use in DeviceManager

1 files changed, 25 insertions, 0 deletions

diff --git a/kernel/fde/fde.go b/kernel/fde/fde.go
index 65e96679f4..cfe0fc507d 100644
--- a/kernel/fde/fde.go
+++ b/kernel/fde/fde.go
@@ -116,3 +116,28 @@ func InitialSetup(runSetupHook RunSetupHookFunc, params *InitialSetupParams) (*I
	}
	return res, nil
 }
+
+// CheckFeatures returns the features of fde-setup hook.
+func CheckFeatures(runSetupHook RunSetupHookFunc) ([]string, error) {
+	req := &SetupRequest{
+	Op: "features",
+	}
+	output, err := runSetupHook(req)
+	if err != nil {
+	return nil, err
+	}
+	var res struct {
+	Features []string `json:"features"`
+	Error string `json:"error"`
+	}
+	if err := json.Unmarshal(output, &res); err != nil {
+	return nil, fmt.Errorf("cannot parse hook output %q: %v", output, err)
+	}
+	if res.Features == nil && res.Error == "" {
+	return nil, fmt.Errorf(`cannot use hook: neither "features" nor "error" returned`)
+	}
+	if res.Error != "" {
+	return nil, fmt.Errorf("cannot use hook: it returned error: %v", res.Error)
+	}
+	return res.Features, nil
+}