[tor-commits] [torspec/master] Prop 311: Avoid depending on exact extend details

[teor at torproject.org]

commit 6eee2ca426bb45faf3b53b481dea956aaecc7dbf
Author: teor <teor at torproject.org>
Date:   Thu Jan 30 08:29:51 2020 +1000

    Prop 311: Avoid depending on exact extend details
    
    We don't want to depend on extends preferring IPv4 or IPv6,
    or the exact extend implementation, if we don't have to.
    
    Part of 24404.
---
 proposals/311-relay-ipv6-reachability.txt | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/proposals/311-relay-ipv6-reachability.txt b/proposals/311-relay-ipv6-reachability.txt
index d2f6b70..ace1704 100644
--- a/proposals/311-relay-ipv6-reachability.txt
+++ b/proposals/311-relay-ipv6-reachability.txt
@@ -213,6 +213,14 @@ Ticket: #24404
    way, and lets us migrate from the current behavior to the 3.3.1 behavior
    down the road.
 
+   However, it might not be necessary: clients should not care if their
+   extends are over IPv4 or IPv6, they just want to get to an exit safely.
+   (And clients should not depend on using IPv4 or IPv6, because relays may
+   use an existing authenticated connection to extend.) The only use case
+   where extends might want to prefer IPv4 or IPv6 is relay reachability
+   tests. But we want our reachability test design to succeed, without
+   depending on the specific extend implementation.
+
 3.4. Rejected Extend Designs
 
    Some designs may never be suitable for the Tor network.