Replace the 177 fallbacks originally introduced in Tor 0.2.9.8 in
December 2016 (of which ~126 were still functional), with a list of
151 fallbacks (32 new, 119 existing, 58 removed) generated in May 2017.
Resolves ticket 21564.
Replace the 81 remaining fallbacks of the 100 originally introduced
in Tor 0.2.8.3-alpha in March 2016, with a list of 177 fallbacks
(123 new, 54 existing, 27 removed) generated in December 2016.
Resolves ticket 20170.
If we manually remove fallbacks in C by adding '/*' and '*/' on separate
lines, stem still parses them as being present, because it only looks at
the start of a line.
Add a comment to this effect in the generated source code.
Remove a fallback that changed its fingerprint after it was listed
This happened after to a software update:
https://lists.torproject.org/pipermail/tor-relays/2016-June/009473.html
Remove a fallback that changed IPv4 address
Remove two fallbacks that were slow to deliver consensuses,
we can't guarantee they'll be fast in future.
Blacklist all these fallbacks until operators confirm they're stable.
Allow fallback directories which have been stable for 7 days
to work around #18050, which causes relays to submit descriptors
with 0 DirPorts when restarted. (Particularly during Tor version
upgrades.)
Ignore low fallback directory count in alpha builds.
Set the target count to 50.
Allow fallback directories which have been stable for 30 days
to work around #18050, which causes relays to submit descriptors
with 0 DirPorts when restarted. (Particularly during Tor version
upgrades.)
Ignore low fallback directory count in alpha builds.
"Tor has included a feature to fetch the initial consensus from nodes
other than the authorities for a while now. We just haven't shipped a
list of alternate locations for clients to go to yet.
Reasons why we might want to ship tor with a list of additional places
where clients can find the consensus is that it makes authority
reachability and BW less important.
We want them to have been around and using their current key, address,
and port for a while now (120 days), and have been running, a guard,
and a v2 directory mirror for most of that time."
Features:
* whitelist and blacklist for an opt-in/opt-out trial.
* excludes BadExits, tor versions that aren't recommended, and low
consensus weight directory mirrors.
* reduces the weighting of Exits to avoid overloading them.
* places limits on the weight of any one fallback.
* includes an IPv6 address and orport for each FallbackDir, as
implemented in #17327. (Tor won't bootstrap using IPv6 fallbacks
until #17840 is merged.)
* generated output includes timestamps & Onionoo URL for traceability.
* unit test ensures that we successfully load all included default
fallback directories.
Closes ticket #15775. Patch by "teor".
OnionOO script by "weasel", "teor", "gsathya", and "karsten".
