sd-varlink: add sd_varlink_call_and_upgradeb() + sd_varlink_call_and_upgradebo()

This are to the existing sd_varlink_call_and_upgrade() what
sd_varlink_callb() and sd_varlink_callbo() are to sd_varlink_call():
they put together an object on the fly, via the usual JSON builder
logic.

src/libsystemd/libsystemd.sym

@@ -1108,6 +1108,7 @@ global:
 LIBSYSTEMD_262 {
 global:
         sd_varlink_bind_upgrade;
+        sd_varlink_call_and_upgradeb;
         sd_varlink_respond_and_upgrade;
         sd_varlink_respond_and_upgradeb;
 } LIBSYSTEMD_261;

src/libsystemd/sd-varlink/sd-varlink.c

@@ -2183,6 +2183,31 @@ finish:
         return r;
 }
 
+_public_ int sd_varlink_call_and_upgradeb(
+                sd_varlink *v,
+                const char *method,
+                sd_json_variant **ret_parameters,
+                const char **ret_error_id,
+                int *ret_input_fd,
+                int *ret_output_fd,
+                ...) {
+
+        _cleanup_(sd_json_variant_unrefp) sd_json_variant *parameters = NULL;
+        va_list ap;
+        int r;
+
+        assert_return(v, -EINVAL);
+        assert_return(method, -EINVAL);
+
+        va_start(ap, ret_output_fd);
+        r = sd_json_buildv(&parameters, ap);
+        va_end(ap);
+        if (r < 0)
+                return varlink_log_errno(v, r, "Failed to build json message: %m");
+
+        return sd_varlink_call_and_upgrade(v, method, parameters, ret_parameters, ret_error_id, ret_input_fd, ret_output_fd);
+}
+
 _public_ int sd_varlink_callb_ap(
                 sd_varlink *v,
                 const char *method,

src/systemd/sd-varlink.h

@@ -145,6 +145,9 @@ int sd_varlink_callb(sd_varlink *v, const char *method, sd_json_variant **ret_pa
  * Returns > 0 if the connection was upgraded, 0 if a Varlink error occurred (and ret_error_id was set),
  * or < 0 on local failure. */
 int sd_varlink_call_and_upgrade(sd_varlink *v, const char *method, sd_json_variant *parameters, sd_json_variant **ret_parameters, const char **ret_error_id, int *ret_input_fd, int *ret_output_fd);
+int sd_varlink_call_and_upgradeb(sd_varlink *v, const char *method, sd_json_variant **ret_parameters, const char **ret_error_id, int *ret_input_fd, int *ret_output_fd, ...);
+#define sd_varlink_call_and_upgradebo(v, method, ret_parameters, ret_error_id, ret_input_fd, ret_output_fd, ...) \
+        sd_varlink_call_and_upgradeb((v), (method), (ret_parameters), (ret_error_id), (ret_input_fd), (ret_output_fd), SD_JSON_BUILD_OBJECT(__VA_ARGS__))
 
 /* Send method call and begin collecting all 'more' replies into an array, finishing when a final reply is sent */
 int sd_varlink_collect_full(sd_varlink *v, const char *method, sd_json_variant *parameters, sd_json_variant **ret_parameters, const char **ret_error_id, sd_varlink_reply_flags_t *ret_flags);