[tor-commits] [tor/master] Update comment and add changes file for 20942

[nickm at torproject.org]

commit 9a0cf2376de2ea32cf9059c6760b3d6a0c19e6fa
Author: teor <teor2345 at gmail.com>
Date:   Fri Dec 22 21:49:28 2017 +1100

    Update comment and add changes file for 20942
---
 changes/bug20942                    | 3 +++
 scripts/maint/updateFallbackDirs.py | 9 +++++----
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/changes/bug20942 b/changes/bug20942
new file mode 100644
index 000000000..f806ddced
--- /dev/null
+++ b/changes/bug20942
@@ -0,0 +1,3 @@
+  o Minor features (fallback directory mirrors):
+    - Reject any fallback directory mirror that serves an expired consensus.
+      Implements ticket 20942, patch by "minik".
diff --git a/scripts/maint/updateFallbackDirs.py b/scripts/maint/updateFallbackDirs.py
index 8ca5a7296..cf96fc308 100755
--- a/scripts/maint/updateFallbackDirs.py
+++ b/scripts/maint/updateFallbackDirs.py
@@ -98,10 +98,11 @@ DOWNLOAD_MICRODESC_CONSENSUS = True
 # reject consensuses that are older than REASONABLY_LIVE_TIME.
 # For the consensus expiry check to be accurate, the machine running this
 # script needs an accurate clock.
-# We use 24 hours to compensate for #20909, where relays on 0.2.9.5-alpha and
-# 0.3.0.0-alpha-dev and later deliver stale consensuses, but typically recover
-# after ~12 hours.
-# We should make this lower when #20909 is fixed, see #20942.
+#
+# Relays on 0.3.0 and later return a 404 when they are about to serve an
+# expired consensus. This makes them fail the download check.
+# We use a tolerance of 0, so that 0.2.x series relays also fail the download
+# check if they serve an expired consensus.
 CONSENSUS_EXPIRY_TOLERANCE = 0 
 
 # Output fallback name, flags, bandwidth, and ContactInfo in a C comment?