On Wed, Nov 02, 2022 at 04:36:46PM -0700, Jakub Kicinski wrote:

Eish.

Hangbin, I'm still against this. Please go back to my suggestions /
questions. A tracepoint or an attribute should do. Multi-part messages
are very hard to map to normal programming constructs, and I don't
think there is any precedent for mutli-part notifications.

Hi Jakub,

I checked the doc[1], the NLMSGERR_ATTR_MSG could only be in NLMSG_ERROR and
NLMSG_DONE messages. But the tfilter_notify() set the nlmsg type to
RTM_NEWTFILTER. Would you like to help explain what you mean of using
attribute? Should I send a NLMSG_ERROR/NLMSG_DONE message separately after the
tfilter_notify()?

[1] https://www.kernel.org/doc/html//next/userspace-api/netlink/intro.html#ext-ack

Thanks
Hangbin