check types of properties

control.go

@@ -11,11 +11,22 @@ import (
  "net/http"
  "os/user"
  "regexp"
+ "strconv"
 
  systemd "github.com/coreos/go-systemd/v22/dbus"
  dbus "github.com/godbus/dbus/v5"
 )
 
+// A subset of available properties to modify.
+// See https://man7.org/linux/man-pages/man5/systemd.resource-control.5.html.
+var (
+ CPUAccounting = "CPUAccounting"
+ CPUQuotaPerSecUSec = "CPUQuotaPerSecUSec"
+ MemoryAccounting = "MemoryAccounting"
+ MemoryHigh = "MemoryHigh"
+ MemoryMax = "MemoryMax"
+)
+
 type systemdConn struct {
  conn *systemd.Conn
  ctx context.Context
@@ -63,8 +74,11 @@ func controlHandler() http.HandlerFunc {
  return
  }
 
- variant := dbus.MakeVariant(request.Property.Value)
- property := systemd.Property{Name: request.Property.Name, Value: variant}
+ property, err := transform(request.Property)
+ if err != nil {
+ slog.Warn("unable to create systemd property", "err", err.Error())
+ http.Error(w, err.Error(), http.StatusBadRequest)
+ }
 
  sysconn, err := newSystemdConn()
  if err != nil {
@@ -85,6 +99,7 @@ func controlHandler() http.HandlerFunc {
  w.Header().Set("X-Content-Type-Options", "nosniff")
  w.WriteHeader(http.StatusOK)
  response := controlResponse{Unit: unit, Username: username, Property: request.Property}
+ response.Property = request.Property
  err = json.NewEncoder(w).Encode(response)
  if err != nil {
  slog.Error("unable to send encode response", "error", err.Error())
@@ -129,3 +144,22 @@ func getUnit(username string) (string, error) {
  unit := fmt.Sprintf("user-%v.slice", usr.Uid)
  return unit, err
 }
+
+func transform(controlProp controlProperty) (systemd.Property, error) {
+ switch controlProp.Name {
+ case CPUAccounting, MemoryAccounting:
+ val, err := strconv.ParseBool(controlProp.Value)
+ return systemd.Property{Name: controlProp.Name, Value: dbus.MakeVariant(val)}, err
+
+ case CPUQuotaPerSecUSec, MemoryMax, MemoryHigh:
+ if controlProp.Value == "-1" {
+ return systemd.Property{Name: controlProp.Name, Value: dbus.MakeVariant("-1")}, nil
+ }
+ val, err := strconv.ParseUint(controlProp.Value, 10, 64)
+ return systemd.Property{Name: controlProp.Name, Value: dbus.MakeVariant(val)}, err
+
+ default:
+ msg := fmt.Sprintf("property not supported: %v", controlProp.Name)
+ return systemd.Property{}, errors.New(msg)
+ }
+}

control_test.go

@@ -26,7 +26,6 @@ func TestResolveUser(t *testing.T) {
  if err == nil {
  t.Fail()
  }
-
 }
 
 func TestGetUsername(t *testing.T) {