Subject: Re: Linux pseudo pty
To: Thor Lancelot Simon <firstname.lastname@example.org>
From: Greywolf <email@example.com>
Date: 02/19/2001 13:26:06
On Mon, 19 Feb 2001, Thor Lancelot Simon wrote:
# > They're not in the same device numberspace because they're not the same
# > devices. The /dev/pts space is set up by ptmx which basically plumbs
# > a stream between device and process and effectively removes, i.e.,
# > the daemon from the loop, so it doesn't actually have to process anything
# > under Solaris. The telnetd establishes the ptmx connection and then
# > hands all the back/forth communication to the kernel directly. Since
# > the ssh processing layer is not built into the kernel, sshd uses
# > BSD-style ptys and has to remain alive and tend to the encryption.
# That's not really an accurate description. While it is *possible* to push
# an arbitrary protocol-processing module onto a stream, the use of /dev/ptmx
# to acquire a file descriptor for a pty does not imply that any such push
# has occurred.
# You should look at what sshd (if you like), the Borman/MIT telnetd, or
# indeed any other portable program that uses ptys does on systems that
# don't provide BSD-style ptys. /dev/ptmx is used, no magical modules are
# pushed, and everything works pretty much like it would with ptys done the
# BSD way. Or see the Stevens book; there are good examples in there.
As usual, I stand enlightened. I really need to expand my technical
library. Thanks to all for your patience at my buffoonery.
*BSD: Power Your Net.