channel_from_packet_id
Channel *c = channel_from_packet_id(ssh, __func__, "data");
Channel *c = channel_from_packet_id(ssh, __func__, "extended data");
Channel *c = channel_from_packet_id(ssh, __func__, "ieof");
Channel *c = channel_from_packet_id(ssh, __func__, "oclose");
Channel *c = channel_from_packet_id(ssh, __func__, "open confirmation");
Channel *c = channel_from_packet_id(ssh, __func__, "open failure");