In case we decide that the timeout rate is now too high due to our
change of the max synthetic quantile value, this consensus parameter
will allow us to restore it to the previous value.
This is for the other issue we saw in Bug 1335. A large number of high
timeouts were causing the timeout calculation to slowly drift upwards,
especially in conditions of load. This fix repeatedly regenerates all of
our synthetic timeouts whenever the timeout changes, to try to prevent
drift.
It also lowers the timeout cap to help for some cases of Bug 1245, where
some timeout values were so large that we ended up allocating a ton of
scratch memory to count the histogram bins.
The downside is that lowering this cap is affecting our timeout rate.
Unfortunately, the buildtimeout quantile is now higher than the actual
completion rate by what appears to be about 7-10%, which probably
represents the skew in the distribution due to lowering this synthetic
cap.
In my state files, I was seeing several peaks, probably due to different
guards having different latency. This change is meant to better capture
this behavior and generate more reasonable timeouts when it happens. It
is improving the timeout values for my collection of state files.
It's natural for the definition of bandwidth_rule_t to be with the functions
that actually care about its values. Unfortunately, this means declaring
bandwidth_rate_rule_to_string() out of sequence. Someday we'll just rename
reasons.c to strings.c, and put it at the end of or.h, and this will all be
better.
I'm adding this because I can never remember what stuff like 'rule 3'
means. That's the one where if somebody goes limp or taps out, the
fight is over, right?
Treat strings returned from signed_descriptor_get_body_impl() as not
NUL-terminated. Since the length of the strings is available, this is
not a big problem.
Discovered by rieo.
We accidentally freed the internal buffer for bridge stats when we
were writing the bridge stats file or honoring a control port
request for said data. Change the interfaces for
geoip_get_bridge_stats* to prevent these problems, and remove the
offending free/add a tor_strdup.
Fixes bug 1208.
Specifically, there are two cases: a) are we willing to start a new
circuit at a node not in your ExitNodes config option, and b) are we
willing to make use of a circuit that's already established but has an
unsuitable exit.
Now we discard all your circuits when you set ExitNodes, so the only
way you could end up with an exit circuit that ends at an unsuitable
place is if we explicitly ran out of exit nodes, StrictNodes was 0,
and we built this circuit to solve a stream that needs solving.
Fixes bug in dc322931, which would ignore the just-built circuit because
it has an unsuitable exit.
Before it would prepend your requested entrynodes to your list of guard
nodes, but feel free to use others after that. Now it chooses only
from your EntryNodes if any of those are available, and only falls back
to others if a) they're all down and b) StrictNodes is not set.
Also, now we refresh your entry guards from EntryNode at each consensus
fetch (rather than just at startup and then they slowly rot as the
network changes).
The goal here is to make users less likely to set StrictNodes, since
it's doing closer to what they expect it should be doing.
Fix statistics on client numbers by country as seen by bridges that were
broken in 0.2.2.1-alpha. Also switch to reporting full 24-hour intervals
instead of variable 12-to-48-hour intervals.
The HSAuthorityRecordStats option was used to track statistics of overall
hidden service usage on the version 0 hidden service authorities. With the
version 2 hidden service directories being deployed and version 0
descriptors being phased out, these statistics are not as useful anymore.
Goodbye, you fine piece of software; my first major code contribution to
Tor.
The new rule is: safe_str_X() means "this string is a piece of X
information; make it safe to log." safe_str() on its own means
"this string is a piece of who-knows-what; make it safe to log".
The rule is now: take the value from the CircuitPriorityHalflife
config option if it is set. If it zero, disable the cell_ewma
algorithm. If it is set, use it to calculate the scaling factor.
If it is not set, look for a CircPriorityHalflifeMsec parameter in the
consensus networkstatus. If *that* is zero, then disable the cell_ewma
algorithm; if it is set, use it to calculate the scaling factor.
If it is not set at all, disable the algorithm.
There are two big changes here:
- We store active circuits in a priority queue for each or_conn,
rather than doing a linear search over all the active circuits
before we send each cell.
- Rather than multiplying every circuit's cell-ewma by a decay
factor every time we send a cell (thus normalizing the value of a
current cell to 1.0 and a past cell to alpha^t), we instead
only scale down the cell-ewma every tick (ten seconds atm),
normalizing so that a cell sent at the start of the tick has
value 1.0).
Each circuit is ranked in terms of how many cells from it have been
relayed recently, using a time-weighted average.
This patch has been tested this on a private Tor network on PlanetLab,
and gotten improvements of 12-35% in time it takes to fetch a small
web page while there's a simultaneous large data transfer going on
simultaneously.
[Commit msg by nickm based on mail from Ian Goldberg.]
New config option "CircuitStreamTimeout" to override our internal
timeout schedule for how many seconds until we detach a stream from
a circuit and try a new circuit. If your network is particularly
slow, you might want to set this to a number like 60.
This commit implements a new config option: 'DisableAllSwap'
This option probably only works properly when Tor is started as root.
We added two new functions: tor_mlockall() and tor_set_max_memlock().
tor_mlockall() attempts to mlock() all current and all future memory pages.
For tor_mlockall() to work properly we set the process rlimits for memory to
RLIM_INFINITY (and beyond) inside of tor_set_max_memlock().
We behave differently from mlockall() by only allowing tor_mlockall() to be
called one single time. All other calls will result in a return code of 1.
It is not possible to change DisableAllSwap while running.
A sample configuration item was added to the torrc.complete.in config file.
A new item in the man page for DisableAllSwap was added.
Thanks to Moxie Marlinspike and Chris Palmer for their feedback on this patch.
Please note that we make no guarantees about the quality of your OS and its
mlock/mlockall implementation. It is possible that this will do nothing at all.
It is also possible that you can ulimit the mlock properties of a given user
such that root is not required. This has not been extensively tested and is
unsupported. I have included some comments for possible ways we can handle
this on win32.
