On Fri, Dec 14, 2001 at 11:14:31AM -0600, Edgar Friendly wrote: > Oskar Sandberg <oskar at freenetproject.org> writes: < > > > You obviously can't have every node in the chain restart the request at > > more or less the same time. > > No, you just have the query die and that's it. maybe just change > "queryRestarted" to "Gave up waiting" or so.
The user can give up and try again - but since the new request is likely to get routed back to the same node (even if the node that ate the request is just broken, not an attack) it will hardly make it better. < > > > a) It cannot go on "forever" as the HTL is decremented every time the > > timer is restarted, and will eventually reach zero causing a Timeout. > > > This is not true, as confirmed by scipient's examination of the code > as well as my own personal experience of having a HTL=10 request > return 11 Restarted messages over FCP (which correspond directly to > "queryRestarted", right?) and then fail after a _30 minutes_ of > waiting. I coded it that way - somebody else must have broken it. Since it's a little subtle it's easy to miss, but that was definitely the intention. > > b) Freenet's structure is handles this form of attack well because Nodes > > that don't respond correctly eventually loose references. > > > The attack would be to have a node that handled _lots_ of connections > and then sent "restarted" messages for about a half-hour on each > request, and then finally answered the query. The victim nodes will > not penalize this at all. There are many such "slow down" attacks that are possible - sending the trailing as a "byte trickle" for example would have much the same effect. <> > > The only way to do this better would be to add limited branching to try > > to ensure some redundancy - something that is on that long list of > > things that should be tried in some later version. > > > Limited branching can be good. I didn't say it couldn't - but radical changes right now is not a good idea. > > Thelema > > _______________________________________________ > Devl mailing list > Devl at freenetproject.org > http://lists.freenetproject.org/mailman/listinfo/devl -- Oskar Sandberg oskar at freenetproject.org _______________________________________________ Devl mailing list Devl at freenetproject.org http://lists.freenetproject.org/mailman/listinfo/devl
