If there are multiple validations and data callbacks to register. Do they require only one transaction registration (confd_register_trans_cb)? Or does each validation and data callback require their own transaction callbacks? If there are multiple transaction callbacks will they be over written by the last registration?
you cannot use confd_register_trans_cb for validation as validation registers its init function with confd_register_trans_validate_cb. Both init functions (transaction or validation) have same C declaration, so I assume you can use same function (pointer) for both in case your application logic allows it (usually only confd_trans_set_fd is called in both).