vpp: T9161: Enforce NIC MTU limit and apply MTU to VLAN sub-interfaces

On a VPP-bound interface the MTU limit is the NIC's, which only VPP knows
(the kernel side is an LCP tap reporting a meaningless larger max). Reject at
commit an MTU larger than that limit, read from VPP's 'show hardware-interfaces'
(max mtu + driver frame overhead), so the kernel and dataplane cannot silently
end up with different MTUs.

Also apply a VLAN sub-interface's MTU to its VPP dataplane sub-interface and its
linux-cp tap (created with MTU 0), not just the parent; a sub-interface without
its own MTU inherits the parent's. Covers ethernet (vif/vif-s) and VPP
bond/loopback (vif).

0 files changed, 0 insertions, 0 deletions