meshlink_node_pmtu_cb_t node_pmtu_cb;
meshlink_channel_accept_cb_t channel_accept_cb;
meshlink_node_duplicate_cb_t node_duplicate_cb;
meshlink_node_pmtu_cb_t node_pmtu_cb;
meshlink_channel_accept_cb_t channel_accept_cb;
meshlink_node_duplicate_cb_t node_duplicate_cb;