This commit introduces the consensus parameter "circ_max_cell_queue_size"
which controls the maximum number of cells a circuit queue should have.
The default value is currently 50000 cells which is above what should be
expected but keeps us a margin of error for padding cells.
Related to this is #9072. Back in 0.2.4.14-alpha, we've removed that limit due
to a Guard discovery attack. Ticket #25226 details why we are putting back the
limit due to the memory pressure issue on relays.
Fixes#25226
Signed-off-by: David Goulet <dgoulet@torproject.org>
It is rename to something more meaningful that explains what it does exactly
which is sets the EWMA options (currently only one exists). The new name is
cmux_ewma_set_options().
Also, remove a public function from circuitmux_ewma.h that is only used in the
C file. Make it static inline as well.
Signed-off-by: David Goulet <dgoulet@torproject.org>
To achieve this, a default value for the CircuitPriorityHalflife option was
needed. We still look in the options and then the consensus but in case no
value can be found, the default CircuitPriorityHalflifeMsec=30000 is used. It
it the value we've been using since 0.2.4.4-alpha.
This means that EWMA, our only policy, can not be disabled anymore fallbacking
to the round robin algorithm. Unneeded code to control that is removed in this
commit.
Part of #25268
Signed-off-by: David Goulet <dgoulet@torproject.org>
In 0.3.2.1-alpha, we've added notify_networkstatus_changed() in order to have
a way to notify other subsystems that the consensus just changed. The old and
new consensus are passed to it.
Before this patch, this was done _before_ the new consensus was set globally
(thus NOT accessible by getting the latest consensus). The scheduler
notification was assuming that it was set and select_scheduler() is looking at
the latest consensus to get the parameters it might needs. This was very wrong
because at that point it is still the old consensus set globally.
This commit changes the notify_networkstatus_changed() to be the "before"
function and adds an "after" notification from which the scheduler subsystem
is notified.
Fixes#24975
In 0.3.2.1-alpha, we've added this function in order to have a way to notify
other subsystems that the consensus just changed. The old consensus and the
new one are passed to it.
Before this patch, this was done _before_ the new consensus was set globally
(thus NOT accessible by getting the latest consensus). The scheduler
notification was assuming that it was set and select_scheduler() is looking at
the latest consensus to get the parameters it might needs. This was very wrong
because at that point it is still the old consensus set globally.
With this commit, notify_networkstatus_changed() has been moved _after_ the
new consensus is set globally. The main obvious reasons is to fix the bug
described above and in #24975. The other reason is that this notify function
doesn't return anything which could be allowing the possibility of refusing to
set the new consensus on error. In other words, the new consensus is set right
after the notification whatever happens.
It does no harm or change in behavior to set the new consensus first and then
notify the subsystems. The two functions currently used are for the control
port using the old and new consensus and sending the diff. The second is the
scheduler that needs the new consensus to be set globally before being called.
Of course, the function has been documented accordinly to clearly state it is
done _after_ the new consensus is set.
Fixes#24975
Signed-off-by: David Goulet <dgoulet@torproject.org>
This commit introduces the src/or/dos.{c|h} files that contains the code for
the Denial of Service mitigation subsystem. It currently contains basic
functions to initialize and free the subsystem. They are used at this commit.
The torrc options and consensus parameters are defined at this commit and
getters are implemented.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Retry directory downloads when we get our first bridge descriptor
during bootstrap or while reconnecting to the network. Keep retrying
every time we get a bridge descriptor, until we have a reachable bridge.
Stop delaying bridge descriptor fetches when we have cached bridge
descriptors. Instead, only delay bridge descriptor fetches when we
have at least one reachable bridge.
Fixes bug 24367; bugfix on 0.2.0.3-alpha.
networkstatus_consensus_has_ipv6() tells us whether the consensus method of
our current consensus supports IPv6 ORPorts in the consensus.
Part of #23827.
This patch is a result of auditing all of our uses of
get_datadir_fname() and its kin, and dividing them into cache vs
keys vs other data.
The new get_keydir_fname() and get_cachedir_fname() functions don't
actually do anything new yet.
Stop checking for bridge descriptors when we actually want to know if
any bridges are usable. This avoids potential bootstrapping issues.
Fixes bug 24367; bugfix on 0.2.0.3-alpha.
Stop stalling when bridges are changed at runtime. Stop stalling when
old bridge descriptors are cached, but they are not in use.
Fixes bug 24367; bugfix on 23347 in 0.3.2.1-alpha.
DisableNetwork is a subset of net_is_disabled(), which is (now) a
subset of should_delay_dir_fetches().
Some of these changes are redundant with others higher or lower in
the call stack. The ones that I think are behavior-relevant are
listed in the changes file. I've also added comments in a few
places where the behavior is subtle.
Fixes bug 12062; bugfix on various versions.
Because the HS and SR subsystems can use the voting schedule early (with the
changes in #23623 making the SR subsystem using the static voting schedule
object), we need to recalculate the schedule very early when setting the new
consensus.
Fixes#24161
Signed-off-by: David Goulet <dgoulet@torproject.org>
Sometimes when we call exit(), it's because the process is
completely hopeless: openssl has a broken AES-CTR implementation, or
the clock is in the 1960s, or something like that.
But sometimes, we should return cleanly from tor_main() instead, so
that embedders can keep embedding us and start another Tor process.
I've gone through all the exit() and _exit() calls to annotate them
with "exit ok" or "XXXX bad exit" -- the next step will be to fix
the bad exit()s.
First step towards 23848.
