// handleCallMessage handles a received call message. It mutates the
// capability table of its parameter. The caller holds onto c.mu.
func (c *Conn) handleCallMessage(m rpccapnp.Message) error {
mcall, err := m.Call()
if err != nil {
return err
}
mt, err := mcall.Target()
if err != nil {
return err
}
if mt.Which() != rpccapnp.MessageTarget_Which_importedCap && mt.Which() != rpccapnp.MessageTarget_Which_promisedAnswer {
um := newUnimplementedMessage(nil, m)
return c.sendMessage(um)
}
mparams, err := mcall.Params()
if err != nil {
return err
}
if err := c.populateMessageCapTable(mparams); err == errUnimplemented {
um := newUnimplementedMessage(nil, m)
return c.sendMessage(um)
} else if err != nil {
c.abort(err)
return err
}
ctx, cancel := c.newContext()
id := answerID(mcall.QuestionId())
a := c.insertAnswer(id, cancel)
if a == nil {
// Question ID reused, error out.
c.abort(errQuestionReused)
return errQuestionReused
}
meth := capnp.Method{
InterfaceID: mcall.InterfaceId(),
MethodID: mcall.MethodId(),
}
paramContent, err := mparams.ContentPtr()
if err != nil {
return err
}
cl := &capnp.Call{
Ctx: ctx,
Method: meth,
Params: paramContent.Struct(),
}
if err := c.routeCallMessage(a, mt, cl); err != nil {
return a.reject(err)
}
return nil
}
