Going from 4 hours to 24 hours in order to try reduce the efficiency of guard
discovery attacks.
Closes#23856
Signed-off-by: David Goulet <dgoulet@torproject.org>
The goal here is to replace our use of msec-based timestamps with
something less precise, but easier to calculate. We're doing this
because calculating lots of msec-based timestamps requires lots of
64/32 division operations, which can be inefficient on 32-bit
platforms.
We make sure that these stamps can be calculated using only the
coarse monotonic timer and 32-bit bitwise operations.
First, that test was broken from the previous commit because the
channel_queue_cell() has been removed. This now tests the
channel_process_cell() directly.
Second, it wasn't testing much except if the channel subsystem actually went
through the cell handler. This commit adds more checks on the state of a
channel going from open, receiving a cell and closing.
Third, this and the id_map unit test are working, not the others so they've
been marked as not working and future commit will improve and fix those.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This removed code that was either never reached or irrelevant after the
incoming/outgoing queue removal such as the "timestamp_drained".
Lots of things are also removed from channel.h that do not exists anymore or
not used.
Signed-off-by: David Goulet <dgoulet@torproject.org>
If the channel layer failed to write a cell from the circuit queue, requeue it
so it can be retried on the same channel later.
Signed-off-by: David Goulet <dgoulet@torproject.org>
The channel_write_cell() and channel_write_var_cell() can't be possibly called
nor are used by tor. We only write on the connection outbuf packed cell coming
from the scheduler that takes them from the circuit queue.
This makes channel_write_packed_cell() the only usable function. It is
simplify and now returns a code value. The reason for this is that in the next
commit(s), we'll re-queue the cell onto the circuit queue if the write fails.
Finally, channel unit tests are being removed with this commit because they do
not match the new semantic. They will be re-written in future commits.
Signed-off-by: David Goulet <dgoulet@torproject.org>
The channel subsystem was doing a whole lot to track and try to predict the
channel queue size but they are gone due to previous commit.
Signed-off-by: David Goulet <dgoulet@torproject.org>
For the rationale, see ticket #23709.
This is a pretty massive commit. Those queues were everywhere in channel.c and
it turns out that it was used by lots of dead code.
The channel subsystem *never* handles variable size cell (var_cell_t) or
unpacked cells (cell_t). The variable ones are only handled in channeltls and
outbound cells are always packed from the circuit queue so this commit removes
code related to variable and unpacked cells.
However, inbound cells are unpacked (cell_t), that is untouched and is handled
via channel_process_cell() function.
In order to make the commit compile, test have been modified but not passing
at this commit. Also, many tests have been removed but better improved ones
get added in future commits.
This commit also adds a XXX: which indicates that the handling process of
outbound cells isn't fully working. This as well is fixed in a future commit.
Finally, at this commit, more dead code remains, it will be cleanup in future
commits.
Fixes#23709
Signed-off-by: David Goulet <dgoulet@torproject.org>
This function is part of the tor fast path so this commit adds more
documentation to it as it is critical.
Signed-off-by: David Goulet <dgoulet@torproject.org>
append_cell_to_circuit_queue() had code disabled from commit
2a95f31716
This code is 4+ years old related to bug #9072 so if we ever want to revisit
it, lets inspect/revert this commit.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Added clarifying information in man file about RelayBandwidthRate and
RelayBandwidthBurst options that exclude directory fetches by relays.
Fixes#24318
Signed-off-by: Fernando Fernandez Mancera <ffernandezmancera@gmail.com>
