Re: Comments on draft-ietf-secsh-filexfer-05.txt

[Joseph Galbraith <galb-list%vandyke.com@localhost>]

Damien Miller wrote:
> Another comment/query on the filexfer draft:
>
> I think that SSH_FXP_OPEN should support a flag to stop it from
> following symlinks, like O_NOFOLLOW on some Unices.
>
> Without something like this, I believe that SSH_FXP_FSTAT isn't very
> useful as a race-free means to collect attributes. One could end up
> following a symlink unless one checks it first - which opens another race.
>
> Even using the hypothetical nofollow isn't entirely race-free, but it
> enables a server to not chase symlinks (e.g. to /dev/st0) if it doesn't
> want to.

If no one else has any thoughts or objections to this,
I will add it to the draft as follows:

New flag to open command:

    SSH_FXF_NOFOLLOW                  = 0x00000200

SSH_FXF_NOFOLLOW
  If the final component of the path is a symlink, the link
  file itself should be opened instead of the the target.

What should the behavior be if a symlink file is opened and
then read or written to?

Thanks,

- Joseph