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.
We do this in too many places throughout the code; it's time to start
clamping down.
Also, refactor Karsten's patch to use strchr-then-strndup, rather than
malloc-then-strlcpy-then-strchr-then-clear.
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.
In connection_dir_client_reached_eof, we make sure that we either
return when we get an http status code of 503 or handle the problem
and set it to 200. Later we check if the status code is 503. Remove
that check.
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.]
This changes the pqueue API by requiring an additional int in every
structure that we store in a pqueue to hold the index of that structure
within the heap.
Some *_free functions threw asserts when passed NULL. Now all of them
accept NULL as input and perform no action when called that way.
This gains us consistence for our free functions, and allows some
code simplifications where an explicit null check is no longer necessary.
Do not segfault when writing buffer stats when we haven't observed a
single circuit to report about. This is a minor bug that would only show
up in testing environments with no traffic and with reduced stats
intervals.
Avoid crashing if the client is trying to upload many bytes and the
circuit gets torn down at the same time, or if the flip side
happens on the exit relay. Bugfix on 0.2.0.1-alpha; fixes bug 1150.
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.
To fix a major security problem related to incorrect use of
SSL/TLS renegotiation, OpenSSL has turned off renegotiation by
default. We are not affected by this security problem, however,
since we do renegotiation right. (Specifically, we never treat a
renegotiated credential as authenticating previous communication.)
Nevertheless, OpenSSL's new behavior requires us to explicitly
turn renegotiation back on in order to get our protocol working
again.
Amusingly, this is not so simple as "set the flag when you create
the SSL object" , since calling connect or accept seems to clear
the flags.
For belt-and-suspenders purposes, we clear the flag once the Tor
handshake is done. There's no way to exploit a second handshake
either, but we might as well not allow it.
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.
If your relay can't keep up with the number of incoming create cells, it
would log one warning per failure into your logs. Limit warnings to 1 per
minute.
This was left over from an early draft of the microdescriptor code; it
began to populate the signatures array of a networkstatus vote, even
though there's no actual need to do that for a vote.
In C, the code "char x[10]; if (x) {...}" always takes the true branch of
the if statement. Coverity notices this now.
In some cases, we were testing arrays to make sure that an operation
we wanted to do would suceed. Those cases are now always-true.
In some cases, we were testing arrays to see if something was _set_.
Those caes are now tests for strlen(s), or tests for
!tor_mem_is_zero(d,len).
If all authorities restart at once right before a consensus vote, nobody
will vote about "Running", and clients will get a consensus with no usable
relays. Instead, authorities refuse to build a consensus if this happens.
The first happens on an error case when a controller wants an
impossible directory object. The second happens when we can't write
our fingerprint file.
The code for these was super-wrong, but will only break things when we
reset an option on a platform where sizeof(time_t) is different from
sizeof(int).
See task 1114. The most plausible explanation for someone sending us weak
DH keys is that they experiment with their Tor code or implement a new Tor
client. Usually, we don't care about such events, especially not on warn
level. If we really care about someone not following the Tor protocol, we
can set ProtocolWarnings to 1.
This patch introduces a new type called document_signature_t to represent the
signature of a consensus document. Now, each consensus document can have up
to one document signature per voter per digest algorithm. Also, each
detached-signatures document can have up to one signature per <voter,
algorithm, flavor>.
Previously, we insisted that a valid signature must be a signature of
the expected digest. Now we accept anything that starts with the
expected digest. This lets us include another digest later.
