FDCM_DATASIZE
if (cmp->cmsg_len != CMSG_LEN(FDCM_DATASIZE))
fdcm = malloc(CMSG_SPACE(FDCM_DATASIZE));
memset(fdcm, 0, CMSG_SPACE(FDCM_DATASIZE));
msg.msg_controllen = CMSG_LEN(FDCM_DATASIZE);
cmp->cmsg_len = CMSG_LEN(FDCM_DATASIZE);
#define MESSAGE_SIZE (CMSG_SPACE(FDCM_DATASIZE) + \