TCPMD5_INPUT
TCPMD5_INPUT(m, th, to.to_signature) != 0)
TCPMD5_INPUT(m, th, to->to_signature) != 0)) {
TCPMD5_INPUT(m, th, to->to_signature) != 0) {
TCPMD5_INPUT(m, th, to->to_signature) != 0)
TCPMD5_INPUT(m, NULL, NULL) != ENOENT)