outsourcing DCE/RPC to alternate programs - runtime config option

[tridge at samba.org]

Metze,

 > for samba 4 this could be easily done by implenting another
 > ntvfs_ipc module that passes the data to a pipe and the epmapper
 > module should be extented to return mappings which are registered
 > by other applications via a private socket and a epm_Insert() call
 > and we should then store the mapping in a persitent db

I don't think it is so useful to do this at the ntvfs level. The ntvfs
level is before the bind, so you could only switch based on pipe name
for ncacn_np, and you could not handle ncacn_ip_tcp or other
transports at all. As a single ncacn_np pipe name is often used to
handle many rpc interfaces (such as with lsass), this would not allow
external implementations much flexibility in what interfaces they
handle.

I think it would be much more appropriate to handle this using hooks
in the rpc_server code. Something based on similar ideas to your
dcesrv_remote.c code would perhaps be a good place to start. Maybe
using an interface based on unix domain sockets for the forwarding of
packets.

Of course, some external users might just want the raw pipe data, as
not all named pipes are used for DCE/RPC, so a ntvfs level forwarding
module isn't a bad thing to have, but I suspect the majority of
external users will want to use it for DCE/RPC so something that suits
that and allows support of all rpc transports is probably more widely
useful.

Cheers, Tridge