/usr/include/libr/sflib/ is in libradare2-dev 0.9.6-3.1+deb8u1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/libr/sflib/common/
/usr/include/libr/sflib/common/sfsocketcall.h
/usr/include/libr/sflib/common/sftypes.h
/usr/include/libr/sflib/darwin-x86-32/
/usr/include/libr/sflib/darwin-x86-32/sflib.h
/usr/include/libr/sflib/darwin-x86-32/sfsyscall.h
/usr/include/libr/sflib/darwin-x86-32/sfsysnr.h
/usr/include/libr/sflib/linux-x86-32/
/usr/include/libr/sflib/linux-x86-32/sflib.h
/usr/include/libr/sflib/linux-x86-32/sfsyscall.h
/usr/include/libr/sflib/linux-x86-32/sfsysnr.h
/usr/include/libr/sflib/linux-x86-64/
/usr/include/libr/sflib/linux-x86-64/sflib.h
/usr/include/libr/sflib/linux-x86-64/sfsyscall.h
/usr/include/libr/sflib/linux-x86-64/sfsysnr.h