Re: Stateless SFTP server and READDIR race condition.

[der Mouse <mouse%Rodents.Montreal.QC.CA@localhost>]

> This is kind of a nit-pick, but I seems to me that the SFTP server
> cannot be implemented as a stateless server because the server must
> track the directory offset to support multiple READDIR calls.

I don't think you'd want to anyway, because the key exchange and
authentication overhead would be insane.  Rememebr that SFTP is
intended to be used as an SSH subsystem, and it's designed for that
environment.  While it doesn't necessarily have to be done there, it
does mean that its design tradeoffs are partially optimized for that
environment.

> Also, there is a potential race condition when there are multiple
> READDIR calls.

Could you detail this?  I don't see any race condition unless there are
directory-modifying calls involved.

> Second, since SFTP returns multiple directory entries instead of one
> (as is the case with NFS)

...huh?  There's no inherent reason a single NFS READDIR can't return
multiple directory entries.  A server that refuses to do so when there
is space available I would be tempted to call defective, unless there
is some unusual justification (such as its running on a microcontroller
or some such).

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