Re: R. Thomas's NFS question

[yogo () math tau ac il (Yossi Gottlieb)]

> Linux unless you start mountd with a certain flag.  if you do start mountd
> with the proper flag, Linux will re-export an imported filesystem!  ugh.
> i spoke with a comrade, and he stated that this was a hack, inserted into
> the Linux mountd code, by a (his words) "rogue programmer".  now, as for
> the usefullness or logic of this idea...

This regards to intentionally exporting remote filesystems. You may note
however that even if you do not intentionally export the filesystem,
it is still possible to access it by symlinks (to directories, if I
my memory serves me well, as symlinks to files are not treated by the
nfsd). 

I remember I could read otherwise-unreadable files on a SunOS 4.1.x,
which was mounted on a Linux box. The linux box did not export anything,
but by calculating filehandles I could manually read files from it by
'talking' to its nfsd directly. those files were actually symlinks I
created (by logging into the machine).  Again, it wasn't that straight-
forward, i.e. there *was* some bug/misbehaviour of the nfsd, but it 
eventually worked. I don't remember all details but I can try it once
again if there's demand for this...

 

yossi.