[cap-talk] Designation linux kernel patch concept

[James A. Donald]

Mark Seaborn wrote:
 > Yes, Linux seems to be facing the problem at the
 > moment having pressures to add interfaces but without
 > having a good framework for doing so.  Now if only
 > they had some sort of generic object invocation
 > interface... :-)

This crisis is analogous to the DLL Hell that Microsoft
faced, which it successfully resolved with IDL, COM, and
MIDL.

IDL means "Interface description language"

COM was various things, they never made up their mind
what it meant, but the most important thing was a
protocol for interface negotiation.

MIDL was a compiler that compiled interface description
language into C++ code that implemented that interface
and interface negotiation - thereby ensuring that
everyone used the same methods to find out what
interfaces were available, and to advertise what
interfaces they made available.

IDL/COM was designed for calls within a single address
space and a single thread, and worked great for this
problem, but their efforts to extend it to inter thread,
inter process, and across network calls varied from bad
to catastrophic.  An analogous system for linux needs to
be network centric, needs to assume calls can be between
machines, and that the entity that installed the
operating system on one machine and the networking
software on the router may not necessarily be trusted by
the entity that is invoking the interface - should not
assume that user mode code is untrusted but OS code is
trusted.