kern/60791: route in npf(7) needs a via option to specify next hop explicitly

["joe%ns1.eloisystems.com@localhost via gnats" <gnats-admin%NetBSD.org@localhost>]

>Number:         60791
>Category:       kern
>Synopsis:       route in npf(7) needs a via option to specify next hop explicitly
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Sep 25 16:30:00 +0000 2026
>Originator:     Emmanuel Nyarko
>Release:        NetBSD current
>Organization:
NetBSD
>Environment:
NetBSD 11.9.8
>Description:

in npf route procedure, we need a "via" option as part of the routing options.

main purpose is to set the next hop/ gateway of the new interface we are forcing our packets through. This is because some traffic might not be able to reach their next hop from the main route based on the real destination address.
>How-To-Repeat:

Code inspection.
>Fix:

Yes please!