2009/470 tcp_keepalive For inetd Services

[Nicolas Williams]

On Fri, Aug 28, 2009 at 11:12:37PM +0100, Andrew Gabriel wrote:
> This is quite different from any of the existing inetd configuration 
> parameters - inetd doesn't currently allow manipulation of socket 
> configuration parameters.

But maybe it should.  There's a large variety of potentially useful
socket options to use, including IP_SEC_OPT (on listening sockets).

> Please can you describe a case where this is intended to be used? (I 
> ask, because mostly whenever I do see it being used, the author 
> misunderstood what it does and shouldn't have been using it.)

The thread on networking-discuss made it clear: it's for use with
protocols like TELNET and rlogin where there's no app-layer keepalive
(compare to SSHv2, where we have app-layer keepalive features; see
ClientAlive, ServerAlive, and related ssh_config/sshd_config options).

As with all keepalives this is to... keep idle connections alive.

> Why do you intend to allow access to this socket parameter, but no 
> others (such as SO_SNDBUF, SO_RCVBUF, etc)?

I asked about that too.  I'd like to see the keepalive timer interface
set this way too.  But I don't think this case is so incomplete without
those that it should be TCR'ed to add them.  I think this is a great
OpenSolaris contribution story.

[Note: I'm not part of the i-team.]

Cheers,

Nico
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