kern/60387: experimental wg(4) should be able to bind to an interface or address

["campbell+netbsd%mumble.net@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60387
>Category:       kern
>Synopsis:       experimental wg(4) should be able to bind to an interface or address
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Tue Jun 30 00:25:00 +0000 2026
>Originator:     Taylor R Campbell
>Release:        current, 11, 10
>Organization:
The NetWG Boundation, Inc.
>Environment:
>Description:

	A wg(4) interface can be configured to listen on a given port
	number with `wgconfig wgN set listen-port <port>', but it binds
	to any address at that port number, v4 or v6.

	It should be possible to also make it bind to a particular
	address, and/or perhaps address family or interface.

>How-To-Repeat:

	try to listen only on a private address rather than all
	addresses including public ones

>Fix:

	Possible additions:

	- wgconfig wgN set listen-address <addr>[:<port>]
	- wgconfig wgN set listen-interface ifN