CVS update: tng/source/passdb
Christopher R. Hertel
crh at nts.umn.edu
Tue Jan 8 12:44:03 GMT 2002
> David Allan Finch wrote:
> >Simo Sorce wrote:
> >>It has been created as a file and print sharing tool, where MS forced then
> >>to add support of a little amount of dce/rpc (and lately ldap) to maintain compatibility, this is the only reason why rpc made it's way into samba I think.
> >Nope - SMB "is" an RPC protocol
> Hmmm, I think you need to tell us what you think an RPC protocol is?
Being pedantic, he's right that SMB can be seen as a primitive RPC-style
protocol. The packets identify operations and pass parameters to those
operations. In the more formal sense of RPC, that is, an RPC system in
which the marshalling, unmarshalling mechanisms are prescriged and the
interfaces are defined using some form of IDL... well, SMB doesn't
Of course, many client-server protocols can be seen as RPC-style
protocols. All that's required in order for a protocol to look like RPC
is that each packet identify the proceedure it is calling.
The original idea behind RPC is that the RPC call not look any different
to the programmer than a local proceedure call. The original idea behind
SMB was that it bundled up local DOS calls and shoved them into NetBIOS.
Again, a primative RPC mechanism.
None of that is important, however, as none of it supports any of David's
original argument's against Simo's message.
> Please tell us how an 'RPC protocol' differs from a client/server protocol?
The distiction was not clear in David's original message, nor was it
important. RPC protocols *are*, by their very nature, client/server.
Again, what makes RPC RPC is simply that a function-call interface is
available to the programmer. There are details underlying that interface.
A more formal RPC system will have things like IDL, a hidden
[un]marshalling layer, etc. SMB over NetBIOS has primitive analogs, so it
can be viewed as an RPC system, if it's useful to view it that way.
Christopher R. Hertel -)----- University of Minnesota
crh at nts.umn.edu Networking and Telecommunications Services
Ideals are like stars; you will not succeed in touching them
with your hands...you choose them as your guides, and following
them you will reach your destiny. --Carl Schultz
More information about the samba-technical