/usr/include/freefoam/fieldFunctionObjects/ is in libfreefoam-dev 0.1.0+dfsg+1-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/freefoam/fieldFunctionObjects/IOFieldAverage.H
/usr/include/freefoam/fieldFunctionObjects/IOcellSource.H
/usr/include/freefoam/fieldFunctionObjects/IOfaceSource.H
/usr/include/freefoam/fieldFunctionObjects/IOfieldMinMax.H
/usr/include/freefoam/fieldFunctionObjects/IOsurfaceInterpolateFields.H
/usr/include/freefoam/fieldFunctionObjects/cellSource.H
/usr/include/freefoam/fieldFunctionObjects/cellSourceFunctionObject.H
/usr/include/freefoam/fieldFunctionObjects/cellSourceI.H
/usr/include/freefoam/fieldFunctionObjects/cellSourceTemplates.C
/usr/include/freefoam/fieldFunctionObjects/faceSource.H
/usr/include/freefoam/fieldFunctionObjects/faceSourceFunctionObject.H
/usr/include/freefoam/fieldFunctionObjects/faceSourceI.H
/usr/include/freefoam/fieldFunctionObjects/faceSourceTemplates.C
/usr/include/freefoam/fieldFunctionObjects/fieldAverage.H
/usr/include/freefoam/fieldFunctionObjects/fieldAverageFunctionObject.H
/usr/include/freefoam/fieldFunctionObjects/fieldAverageItem.H
/usr/include/freefoam/fieldFunctionObjects/fieldAverageTemplates.C
/usr/include/freefoam/fieldFunctionObjects/fieldMinMax.H
/usr/include/freefoam/fieldFunctionObjects/fieldMinMaxFunctionObject.H
/usr/include/freefoam/fieldFunctionObjects/fieldMinMaxTemplates.C
/usr/include/freefoam/fieldFunctionObjects/fieldValue.H
/usr/include/freefoam/fieldFunctionObjects/fieldValueI.H
/usr/include/freefoam/fieldFunctionObjects/fieldValueTemplates.C
/usr/include/freefoam/fieldFunctionObjects/readFields.H
/usr/include/freefoam/fieldFunctionObjects/readFieldsFunctionObject.H
/usr/include/freefoam/fieldFunctionObjects/readFieldsTemplates.C
/usr/include/freefoam/fieldFunctionObjects/surfaceInterpolateFields.H
/usr/include/freefoam/fieldFunctionObjects/surfaceInterpolateFieldsFunctionObject.H
/usr/include/freefoam/fieldFunctionObjects/surfaceInterpolateFieldsTemplates.C