This adds utility functions to help stream block decisions, as well as cpath
layer_hint checks for stream cell acceptance, and syncing stream lists
for conflux circuits.
These functions are then called throughout the codebase to properly manage
conflux streams.
Streams can get blocked on a circuit in two ways:
1. When the circuit package window is full
2. When the channel's cell queue is too high
Conflux needs to decouple stream blocking from both of these conditions,
because streams can continue on another circuit, even if the primary circuit
is blocked for either of these cases.
However, both conflux and congestion control need to know if the channel's
cell queue hit the highwatermark and is still draining, because this condition
is used by those components, independent of stream state.
Therefore, this commit renames the 'streams_blocked_on_chan' variable to
signify that it refers to the cell queue state, and also refactors the actual
stream blocking bits out, so they can be handled separately if conflux is
present.
Because circuit-level sendmes are sent before relay data cells are processed,
we can safely move this to before the conflux decision. In this way,
regardless of conflux being negotiated, we still send sendmes as soon as data
cells are recieved. This avoids introducing conflux queue delay into RTT
measurement, which is important for measuring actual circuit capacity.
The circuit-level tracking must happen inside the call to send a data cell,
since that call now chooses a circuit to send on. Turns out, we were already
doing this kind of here, but only for the digest. Now we do both things here.
We use the oldest-circ-first method here, since that seems good for conflux:
queues could briefly spike, but the bad case is if they are maliciously
bloated to stick around for a long time.
The tradeoff here is that it is possible to kill old circuits on a relay
quickly, but that has always been the case with this algorithm choice.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This adds a `reason` label to the `hs_intro_rejected_intro_req_count` and
`hs_rdv_error_count` metrics introduced in #40755.
Metric look up and intialization is now more a bit more involved. This may be
fine for now, but it will become unwieldy if/when we add more labels (and as
such will need to be refactored).
Also, in the future, we may want to introduce finer grained `reason` labels.
For example, the `invalid_introduce2` label actually covers multiple types of
errors that can happen during the processing of an INTRODUCE2 cell (such as
cell parse errors, replays, decryption errors).
Signed-off-by: Gabriela Moldovan <gabi@torproject.org>
This introduces a couple of new service side metrics:
* `hs_intro_rejected_intro_req_count`, which counts the number of introduction
requests rejected by the hidden service
* `hs_rdv_error_count`, which counts the number of rendezvous errors as seen by
the hidden service (this number includes the number of circuit establishment
failures, failed retries, end-to-end circuit setup failures)
Closes#40755. This partially addresses #40717.
Signed-off-by: Gabriela Moldovan <gabi@torproject.org>
If a circuit only sends a tiny amount of data such that its cwnd is not
full, it won't increase its cwnd above the minimum. Since slow start circuits
should never hit the minimum otherwise, we can just ignore them for RTT reset
to handle this.
Since these are derived from the number of SENDMEs in a cwnd/cc update,
and a cwnd should not exceed ~10k, there's plenty of room in uint16_t
for them, even if the network gets significantly faster.
Also provides some stickiness, so that once full, the congestion window is
considered still full for the rest of an update cycle, or the entire
congestion window.
In this way, we avoid increasing the congestion window if it is not fully
utilized, but we can still back off in this case. This substantially reduces
queue use in Shadow.
Since these are derived from the number of SENDMEs in a cwnd/cc update,
and a cwnd should not exceed ~10k, there's plenty of room in uint16_t
for them, even if the network gets significantly faster.
Also provides some stickiness, so that once full, the congestion window is
considered still full for the rest of an update cycle, or the entire
congestion window.
In this way, we avoid increasing the congestion window if it is not fully
utilized, but we can still back off in this case. This substantially reduces
queue use in Shadow.
Having no TotalBuildTimes along a positive CircuitBuildAbandonedCount
count lead to a segfault. We check for that condition and then BUG + log
warn if that is the case.
It should never happened in theory but if someone modified their state
file, it can lead to this problem so instead of segfaulting, warn.
Fixes#40437
Signed-off-by: David Goulet <dgoulet@torproject.org>
The logic was inverted. Introduced in commit
9155e08450.
This was reported through our bug bounty program on H1. It fixes the
TROVE-2022-002.
Fixes#40730
Signed-off-by: David Goulet <dgoulet@torproject.org>
Mike Perry
David Goulet
Gabriela Moldovan
Alex Xu (Hello71)
Dimitris Apostolou