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.
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.
It is possible that two descriptor upload requests are launched in a very
short time frame which can lead to the second request finishing before the
first one and where that first one will make the HSDir send back a 400
malformed descriptor leading to a warning.
To avoid such, cancel all active directory connections for the specific
descriptor we are about to upload.
Note that this race is still possible on the HSDir side which triggers a log
info to be printed out but that is fine.
Fixes#23457
Signed-off-by: David Goulet <dgoulet@torproject.org>
When option validation or transition is happening, there are no
"current options" -- only "old options" and "maybe new options".
Looking at get_options() is likely a mistake, so have a nonfatal
assertion let us know if we do that.
Closes 22281.
Because we can get a RENDEZVOUS2 cell before the INTRODUCE_ACK, we need to
correctly handle the circuit purpose REND_JOINED that is not change its
purpose when we get an INTRODUCE_ACK and simply close the intro circuit
normally.
Fixes#23455
Signed-off-by: David Goulet <dgoulet@torproject.org>
This test is important because it tests that upload_descriptor_to_all()
is in synch with pick_hsdir_v3(). That's not the case for the
reachability test which just compares the responsible hsdir sets.
There was a bug in upload_descriptor_to_all() where we picked between
first and second hsdir index based on which time segment we are. That's
not right and instead we should be uploading our two descriptors using a
different hsdir index every time. That is, upload first descriptor using
first hsdir index, and upload second descriptor using second hdsir index.
Also simplify stuff in pick_hdsir_v3() since that's only used to fetch
descriptors and hence we can just always use the fetch hsdir index.
This is a large and important unit test for the hidden service version
3! It tests the service reachability for a client using different
consensus timings and makes sure that the computed hashring is the same
on both side so it is actually reachable.
Signed-off-by: David Goulet <dgoulet@torproject.org>
With the latest change on how we use the HSDir index, the client and service
need to pick their responsible HSDir differently that is depending on if they
are before or after a new time period.
The overlap mode is active function has been renamed for this and test added.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Because of #23387, we've realized that there is one scenario that makes
the client unable to reach the service because of a desynch in the time
period used. The scenario is as follows:
+------------------------------------------------------------------+
| |
| 00:00 12:00 00:00 12:00 00:00 12:00 |
| SRV#1 TP#1 SRV#2 TP#2 SRV#3 TP#3 |
| |
| $==========|-----------$===========|-----------$===========| |
| ^ ^ |
| C S |
+------------------------------------------------------------------+
In this scenario the HS has a newer consensus than the client, and the
HS just moved to the next TP but the client is still stuck on the old
one. However, the service is not in any sort of overlap mode so it
doesn't cover the old TP anymore, so the client is unable to fetch a
descriptor.
We've decided to solve this by extending the concept of overlap period
to be permanent so that the service always publishes two descriptors and
aims to cover clients with both older and newer consensuses. See the
spec patch in #23387 for more details.
Based on our #23387 findings, it seems like to maintain 24/7
reachability we need to employ different logic when computing hsdir
indices for fetching vs storing. That's to guarantee that the client
will always fetch the current descriptor, while the service will always
publish two descriptors aiming to cover all possible edge cases.
For more details see the next commit and the spec branch.
Signed-off-by: David Goulet <dgoulet@torproject.org>
The pruning process and the deleting ephemeral service function iterates over
all circuits and were asserting on rend_data for a matching circuit. This is
not good because now we have v3 circuits without a rend_data.
Fixes#23429
Signed-off-by: David Goulet <dgoulet@torproject.org>
Use the valid_after time from the consensus to get the time period number else
we might get out of sync with the overlap period that uses valid_after.
Make it an optional feature since some functions require passing a
specific time (like hs_get_start_time_of_next_time_period()).
Signed-off-by: David Goulet <dgoulet@torproject.org>
