change net.list() output format

Proposed format of the output:

[1] => {
    [application] => {
        [protocol] => dns
    }
    [ip] => 127.0.0.1
    [transport] => {
        [protocol] => tcp
        [security] => tls
        [port] => 853
    }
}

added 1 commit

decdebcb - daemon/bindings/net: change output format of net.list()

Compare with previous version

By default, when listening on both IPv4 and IPv6 using UDP, TCP and TLS, this produces a lot of output. Adding something like net.summary() might be reasonable.

Implementation nitpick: s/lua_pushstring/lua_pushliteral/g docs

If it's too verbose, maybe we could cut it down a little? I might be over-engineering this :-) I wonder whether splitting protocol and security really helps. Lemme test it with variants that come into mind:

description	protocol	security	comment
DNS over UDP	udp	none
DNS over TCP	tcp	none
DNS over TLS	tcp	tls
DNS over DTLS	udp	tls	seems to fit the scheme perfectly
DNS over HTTPS	tcp*	tls*	so our fields won't differ from DoT? (except for port, but that seems mostly orthogonal property to me) Or would that be differentiated by `.application.protocol = "http+dns"` or something? *[]** assuming HTTP < 3 – with =3 it might be udp+quic, probably.
DNSCrypt	udp	dnscrypt?	sounds OK
DNS over QUIC (directly)	udp	quic?	sounds OK

... so altogether it does seem to fit, except for those DoH considerations.

Maybe .application.protocol could be collapsed to .app_protocol, unless we can anticipate adding some other member in future. It would save two lines, but not a big deal.

More importantly, there's a problem in this MR's current model.

$ kresd -a ::1#5353
> net.list()
[1] => {
    [application] => {
        [protocol] => dns
    }
    [ip] => ::1
    [transport] => {
        [protocol] => udp
        [security] => none
        [port] => 5353
    }
}

... but it listens both on UDP and TCP on that port, of course.

EDIT: well, we could simply double the output (in this case), but that might be a bit too much verbose.

added 1 commit

41f04fb2 - daemon/bindings/net: change output format of net.list()

Compare with previous version

The list is flat by design, so every IP/transport combination creates a new entry. This is why it seems quite verbose - just localhost is 6 entries by default.

DoH is supposed to be implemented using the application table. application.protocol could be http and it might introduce additional fields, such as endpoint, or a perhaps type (for plain DNS vs JSON). That's the reason I'd like to keep application as a separate table, so it is extensible.

OK, so the plan is to "double" the list items for the [security] => none cases, right? (They listen both on UDP and TCP.)

Example:

[1] => {
    [application] => {
        [protocol] => dns
    }
    [ip] => 127.0.0.1
    [transport] => {
        [protocol] => udp
        [security] => none
        [port] => 53
    }
}
[2] => {
    [application] => {
        [protocol] => dns
    }
    [ip] => 127.0.0.1
    [transport] => {
        [protocol] => tcp
        [security] => none
        [port] => 53
    }
}
[3] => {
    [application] => {
        [protocol] => dns
    }
    [ip] => 127.0.0.1
    [transport] => {
        [protocol] => tcp
        [security] => tls
        [port] => 853
    }
}

I think this format is quite convenient to process from a script, but it can be quite verbose considering most people will have at least 3 interfaces (127.0.0.1, ::1, public IPv4, ...)