skbuff: carry external ubuf_info in msghdr

Make possible for network in-kernel callers like io_uring to pass in a
custom ubuf_info by setting it in a new field of struct msghdr.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
3 files changed