Is possible to encapsulate a new header in AF_XDP

[ZENOTME]

I'm trying to capture the packet from veth and encapsulate a new eth header to send it out by a real eth nic. As far as I know, in xdp ebpf, we can use bpf_xdp_adjust_head to do something like this. Is possible we can do it in userspace using AF_XDP? E.g. using user head room and adjust the addr of frame desc forward when we want to encapsulate a new header.