On Sat, 2017-05-13 at 19:29 +0200, Jan Moskyto Matejka wrote: > > > When adding a route to the skb, track whether it contains at least > > 1 > > route. If not, it means the next route in the dump is larger than > > the > > given buffer. Detect this condition and error out of the dump - > > returning an error to the user (-ENOSPC? or EMSGSIZE?) > > EMSGSIZE seems OK for me.
If we return an error here, and consequently allow for userspace changes to pick this up, perhaps we could also consider allowing to split the dump between nexthops, so that arbitrary such things can be returned. We did a similar thing in nl80211 at some point - originally, a dump of wireless devices present was doing a whole device per message, we later allowed splitting a single device across multiple messages because capability information was reaching a reasonable message size limit. johannes
