In #23466 we discovered that cached descriptors can stay around on the
client-side for up to 72 hours. In reality we only want those descs to
get cached for the duration of the current time period, since after that
TP is gone the client needs to compute a new blinded key to use for the HS.
In this commit we start using the consensus time (if available) when
cleaning up cached client descriptor entries. That makes sense because
the client uses consensus time anyway for connecting to hidden
services (e.g. computing blinded keys and time periods).
If no recent consensus is available, we consider descriptors to be
expired since we will want to fetch new ones when we get a live
consensus to avoid the Roger bug. If we didn't do that, when Roger
desuspends his laptop there would be a race between Tor fetching a new
consensus, and Tor connecting to the HS which would still cause
reachability issues.
We also turned a rev counter check into a BUG, since we should never
receive a descriptor with a strictly smaller rev counter than the one we
already have, except if there is a bug or if the HSDir wants to mess
with us. In any case, let's turn this into a BUG so that we can detect
and debug such cases easily.
This change refactors find_dl_schedule() to only call dependent functions
as needed. In particular, directory_fetches_from_authorities() only needs
to be called on clients.
Stopping spurious directory_fetches_from_authorities() calls on every
download on public relays has the following impacts:
* fewer address resolution attempts, particularly those mentioned in 21789
* fewer descriptor rebuilds
* fewer log messages, particularly those limited in 20610
Fixes 23470 in 0.2.8.1-alpha.
The original bug was introduced in commit 35bbf2e as part of prop210.
OpenBSD doesn't like tricks where you use a too-wide sscanf argument
for a too-narrow array, even when you know the input string
statically. The fix here is just to use bigger buffers.
Fixes 15582; bugfix on a3dafd3f58 in 0.2.6.2-alpha.
But when clients are just starting, make them try each bridge a few times
before giving up on it.
These changes make the bridge download schedules more explicit: before
17750, they relied on undocumented behaviour and specific schedule
entries. (And between 17750 and this fix, they were broken.)
Fixes 23347, not in any released version of tor.
We were always incrementing bridge download statuses on each attempt,
but we were using the "increment on failure" functions to do it.
And we never incremented them on failure.
No behaviour change.
The download schedule tells Tor to wait 15 minutes before downloading
bridge descriptors. But 17750 made Tor ignore that and start immediately.
Since we fixed 17750, Tor waits 15 minutes for bridge client bootstrap,
like the schedule says.
This fixes the download schedule to start immediately, and to try each
bridge 3 times in the first 30 seconds. This should make bridge bootstraps
more reliable.
Fixes 23347.
