sendfd_payload
ATF_REQUIRE(sendfd_payload(fd[0], putfd, buf, 1) == 1);
len = sendfd_payload(sock[0], dfd, &ch, sizeof(ch));
len = sendfd_payload(sockfd, send_fd, &ch, sizeof(ch));
len = sendfd_payload(fd[0], putfd, buf, sendspace);
len = sendfd_payload(fd[0], putfd, buf, sendspace);
len = sendfd_payload(fd[0], putfd, buf, sizeof(buf));