The directfb backend was supported together with linux-fb backend in GTK+2.10

From gtk+-2.10.2 configure --help we can see (I just only view the 2.10.2, not know other 2.10.x):

--with-gdktarget=[x11/linux-fb/win32/quartz/directfb] select non-default GDK target

 

We can download this directfb supported version gtk+-2.10.2 from http://ftp.gnome.org/pub/gnome/sources/gtk+/2.10/gtk+-2.10.2.tar.bz2