Re: ifconfig v2

[David Young <dyoung%pobox.com@localhost>]

On Wed, Jun 12, 2013 at 08:52:07AM +0200, Manuel Bouyer wrote:
> On Tue, Jun 11, 2013 at 09:50:24PM -0500, David Young wrote:
> > [...]
> > Finally, for the sake of consistency, let's put all of the addresses,
> > even the link-layer address, into <family> <address> form:
> > 
> > wm0: flags < up, running >
> >         media: Ethernet none (none)
> >         link 00:26:2d:f3:c8:c7
> >         inet 169.254.162.222 prefixlen 16
> >         inet6 fe80::226:2dff:fef3:c8c7%wm0 prefixlen 64 scopeid 0x1
> > 
> > That is an efficient and consistent display.  I estimate that it will
> > meet my information needs more than 95% of the time when I run 'ifconfig
> > wm0', and it will meet my needs more quickly than the status quo because
> > it is less cluttered and more compact.
> > 
> > If I need more information, I will ask for it with ifconfig -v wm0:
> > 
> > wm0: flags < up, broadcast, running, simplex, multicast > mtu 1500
> >         capabilities:       ip4csum-rx, ip4csum-tx, tcp4csum-rx, 
> > tcp4csum-tx,
> >                     tcp6csum-rx tcp6csum-tx, tso4, tso6,
> >                     udp4csum-rx, udp4csum-tx, udp6csum-rx, udp6csum-tx
> >         enabled: <none>
> >         ether capabilities: vlan-mtu, vlan-hwtagging, jumbo-mtu
> >         ether enabled: <none>
> >         media: Ethernet none (none)
> >         link 00:26:2d:f3:c8:c7
> >         inet 169.254.162.222 prefixlen 16 broadcast 169.254.255.255
> >         inet6 fe80::226:2dff:fef3:c8c7%wm0 prefixlen 64 scopeid 0x1
> 
> I think capabilities (both supported and enabled) should still be in the
> default output; it's an important information when you're configuring a
> network interface.
> Maybe some of them could be merged, e.g. when you have ip4csum-rx, ip4csum-tx
> print ip4csum (ifconfig accepts this as input).

I like the idea of combining the keywords that way, but even with
compression, the capabilities and enables take at least 4 out of 9 lines
in a fairly normal default display:

wm0: flags < up, running >
        capabilities:   ip4csum, tcp4csum, tcp6csum, tso4, tso6,
                        udp4csum, udp6csum
        enabled: <none>
        ether capabilities: vlan-mtu, vlan-hwtagging, jumbo-mtu
        ether enabled: <none>
        media: Ethernet none (none)
        link 00:26:2d:f3:c8:c7
        inet 169.254.162.222 prefixlen 16
        inet6 fe80::226:2dff:fef3:c8c7%wm0 prefixlen 64 scopeid 0x1

I am pretty sure that most of the time, people are not looking for the
capabilities/enables in the ifconfig output.

I find it hard to ignore the larger issue, though, which is that those
capability flags are only useful insofar as the NetBSD networking stack
and drivers are distrusted or buggy and some masochists like to turn
knobs until they find a combo that works. :-) Ordinarily a driver should
enable the offload capabilities that are known to work reliably, and it
should not advertise the buggy ones.

Dave

-- 
David Young
dyoung%pobox.com@localhost    Urbana, IL    (217) 721-9981