[RFC 1/4] telemetry: allow commands to receive file descriptors

[Stephen Hemminger]

On Tue, 16 Jun 2026 13:32:28 +0100
Bruce Richardson <bruce.richardson at intel.com> wrote:

> On Tue, Jun 09, 2026 at 02:02:02PM -0700, Stephen Hemminger wrote:
> > Add rte_telemetry_register_cmd_fd_arg() to register a command whose
> > callback also receives file descriptors passed by the client as
> > SCM_RIGHTS ancillary data. The callback owns the descriptors and must
> > close them.
> > 
> > This lets a client open a file itself and hand the descriptor to the
> > primary process, so DPDK never opens the path. That avoids path and
> > permission problems and works across container filesystem namespaces.
> > 
> > Existing commands and clients are unaffected. If unsolicited file
> > descriptor is passed, it is closed.
> >   
> 
> This scheme seems reasonable in general. My only concern is whether the
> lack of potential windows support is an issue? For regular telemetry, there
> was always the option of a windows implementation using regular
> TCP/UDP/SCTP sockets bound to localhost. However, AFAIK there is no windows
> implementation of anything that supports file descriptors or handles
> between processes.
> 
> Some other pieces of feedback inline below.
> 
> /Bruce

I have new version (testing) that passes filename as parameter.
That should work without the fd passing.