On Mon, 07 Feb 2000, Mark Spencer wrote:
> I put some mechanisms in the kernel to use the two parameters provided by
> the MPPP spec to decide which should bundle, and provided an override
> capability for pppd, if so desired. I really don't think that the
> userspace programs should have to confer with one another to decide who
> should go in an MP bundle.
I have to disagree here. Deciding which links go in which bundle is
something that can easily be done in userspace and has a large element of
policy about it. Therefore it should be done in userspace. The userspace
stuff (pppd or whatever) then just tells the kernel "attach this link to
this bundle". This keeps the kernel code simple and clean.
> Now, if I'm a LAC, I want to copy PPP frames from a device (say, a tty or
> ISDN driver, or even another pppd) to my L2TP socket... Can this also be
> done with a kernel datapath? My API didn't really have a mechanism for
> doing so, but it would be nice if the new one did.
For a tty you could make a line discipline which would shunt the packets
down the l2tp socket. Alternatively you could have a kernel thread doing
reads and writes on the device and your l2tp socket. That might actually
turn out cleaner.
Paul Mackerras, Senior Open Source Researcher, Linuxcare, Inc.
+61 2 6262 8990 tel, +61 2 6262 8991 fax
Linuxcare. Support for the revolution.