Unix socket support for sshd

[Mantas Mikulėnas]

On 2016-02-04 19:31, Daniel Kahn Gillmor wrote:
> Note that the daemon management service (what systemd's pid 1 provides)
> needs some way to communicate to the spawned daemon which file
> descriptors it has inherited should be treated as listeners.  for
> systemd, this is a contiguious block of file descriptors starting at fd
> 3 (SD_LISTEN_FDS_START), and the enviornment variable LISTEN_FDS is a
> decimal number indicating how many file descriptors to use for listening
> (see sd_listen_fds(3) from libsystemd for more detail).
> 
> A reasonable approach that would avoid linking in libsystemd might be to
> just specify something like ListenFDs N:M (meaning file descriptors N
> through M are sockets you should listen on).  (perhaps -L N:M on the
> command line, so that the config file could stay static and the spawning
> daemon manager could dynamically adjust the invocation as sockets were
> added or removed)
> 
>       --dkg

FWIW, for single-socket configurations, systemd also supports the
inetd-compatible style of assigning the socket directly to fd's 0-2 (stdio).

I've tested it with both `sshd -i` in Accept=yes ("nowait") mode, and
with Exim4 in Accept=no ("wait") mode. It works fine with `sshd -i`.

Also, I assume the scary key generation warning in sshd's manpage only
applies to protocol 1?

-- 
Mantas Mikulėnas <grawity at gmail.com>

[Not sure if this'll reach the list via GMANE, but here goes.]