On Mon, 1 Oct 2018 17:28:29 -0700, David Ahern wrote: > Add a new flag, NLM_F_DUMP_PROPER_HDR, for userspace to indicate to the > kernel that it believes it is sending the right header struct for the > dump message type (ifinfomsg, ifaddrmsg, rtmsg, fib_rule_hdr, ...).
Why is this limited to dumps? Other kind of netlink messages contain the common struct, too. When introducing such mechanism, please make it generic. Last time when we were discussing strict checking in netlink, it was suggested to add a socket option instead of adding NLM flags[1]. It makes a lot of sense: the number of flags is very limited and we'd run out of them pretty fast. It's not just the header structure that is currently checked sloppily. It's also attributes, flags in attributes, etc. We can't assign a flag to all of them. You should also consider a different name for the flag: it should reflect what the effect of the flag is. "Proper header" is not an effect, it's a requirement for the message to pass. The effect is enforced strict checking of the header. Jiri [1] https://marc.info/?l=linux-netdev&m=144492718118955
