bin/53082: ifconfig(8) option: enable/disable all interface capabilities

[martin%NetBSD.org@localhost]

>Number:         53082
>Category:       bin
>Synopsis:       ifconfig(8) option: enable/disable all interface capabilities
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    bin-bug-people
>State:          open
>Class:          change-request
>Submitter-Id:   net
>Arrival-Date:   Thu Mar 08 19:15:00 +0000 2018
>Originator:     Martin Husemann
>Release:        NetBSD 8.99.12
>Organization:
The NetBSD Foundation, Inc.
>Environment:
System: NetBSD night-owl.duskware.de 8.99.12 NetBSD 8.99.12 (NIGHT-OWL) #587: Wed Mar 7 11:44:31 CET 2018 martin%night-owl.duskware.de@localhost:/usr/src/sys/arch/amd64/compile/NIGHT-OWL amd64
Architecture: x86_64
Machine: amd64
>Description:

Some network interface have strange sets of capabilities.
An example:

cnmac1: flags=0x8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
        capabilities=15500<IP4CSUM_Rx,TCP4CSUM_Rx,UDP4CSUM_Rx,TCP6CSUM_Rx>
        capabilities=15500<UDP6CSUM_Rx>
        enabled=0
        ec_capabilities=1<VLAN_MTU>
        ec_enabled=0
        address: 04:18:d6:f0:4b:e5
        media: Ethernet autoselect (none)
        status: no carrier

Now to enable all these offload options, I have to use something like:

ifconfig_cnmac0="udp4csum-rx tcp4csum-rx udp6csum-rx tcp6csum-rx ip4csum-rx"

in /etc/rc.conf (or the equivalent /etc/ifconfig.cnmac0 file).

Sometimes the exact flags change over time when the driver gets fixed
or enhanced.

It would be very convenient to have a shortcut in ifconfig that allows
to enable or disable all existing capabilites with a single command,
like:

 ifconfig cnmac1 enable-all
 ifconfig cnmac1 disable-all

>How-To-Repeat:
n/a

>Fix:
n/a