On Thu, 24 Jul 2014 16:48:21 -0400 grarpamp grarpamp@gmail.com wrote:
On Wed, Jul 23, 2014 at 6:34 PM, Roger Dingledine arma@mit.edu wrote:
On Wed, Jul 23, 2014 at 11:24:47PM +0100, Noel David Torres Taño wrote:
What would happen if a Tor node changes behaviour and uses four or five relay steps instead of three?
At around DEFAULT_ROUTE_LEN 8 or above I get a lot of these, with EXTEND being shown in various command locations, and no connectivity to hidden services. Lower values or 4 or 5 probably work just fine but I didn't bother testing more than a couple clearnet and onion circuits since it's not yet a controller/config tunable and thus takes edit/compile/run time. So even my test of 9 > 5 > 7 > 8 take with salt. Don't know if this likely represent a bug to test more, or just timeouts... the circuits that did work setup in times not feeling much more than time/3*LEN. I'd suggest an undocumented tunable and unit test if it's worth research/statistic/function_checking purpose.
relay_send_command_from_edge_(): Bug: Uh-oh. We're sending a RELAY_COMMAND_EXTEND cell, but we have run out of RELAY_EARLY cells on that circuit. Commands sent before: (unrecognized),(unrecognized),(unrecognized),(unrecognized),EXTEND,EXTEND,(unrecognized)
This is working exactly as specified, and despite the error message, is not a Bug. The number of hops each circuit can extend to is limited by the number of RELAY_EARLY cells allowed per circuit (8), as EXTENDs that are not contained in RELAY_EARLY are dropped.
Roger linked prop 110, but this is also documented in the tor-spec (section 5.6).
Regards,