Bug#805344: systemd: ListenStream=6566 in saned.socket only causes systemd to listen on [::]:6566

[Jens Georg]

>> I was trying to run sane network scanning through socket activation, 
>> but
>> with the provided saned.socket file systemd only listens on a v6 
>> socket.
>> I have to explicitly change ListenStream to 0.0.0.0:6656 to make it
>> listen on v4.
> 
> Did you check if it is actually not reachable over IPv4? IPv6 sockets
> can also accept IPv4 connections unless configured not to do so. This 
> is
> controlled system-wide via /proc/sys/net/ipv6/bindv6only which is "0" 
> on
> my computer (which is the default according to man:systemd.socket(5)).
> 
> systemd by default binds only to IPv6, but uses the system-wide default
> above to also accept IPv4 connections; the default can also be
> overridden per-service via BindIPv6Only= (see man:systemd.socket(5)).

scanimage -L and simple-scan definitely could not connect to saned 
unless I
did said changes.

I will check the other options.

Jens.