They have been off-by-default since 0.2.5 and nobody has complained. :)
Also remove the buf_shrink() function, which hasn't done anything
since we first stopped using contiguous memory to store buffers.
Closes ticket 14848.
The solution I took is to not free a circuit with a pending
uncancellable work item, but rather to set its magic number to a
sentinel value. When we get a work item, we check whether the circuit
has that magic sentinel, and if so, we free it rather than processing
the reply.
When closing parallel introduction points, the given reason (timeout)
was actually changed to "no reason" thus when the circuit purpose was
CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT, we were reporting an introduction
point failure and flagging it "unreachable". After three times, that
intro point gets removed from the rend cache object.
In the case of CIRCUIT_PURPOSE_C_INTRODUCING, the intro point was
flagged has "timed out" and thus not used until the connection to the HS
is closed where that flag gets reset.
This commit adds an internal circuit reason called
END_CIRC_REASON_IP_NOW_REDUNDANT which tells the closing circuit
mechanism to not report any intro point failure.
This has been observed while opening hundreds of connections to an HS on
different circuit for each connection. This fix makes this use case to
work like a charm.
Fixes#13698.
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
We're calling mallocfn() and reallocfn() in the HT_GENERATE macro
with the result of a product. But that makes any sane analyzer
worry about overflow.
This patch keeps HT_GENERATE having its old semantics, since we
aren't the only project using ht.h. Instead, define a HT_GENERATE2
that takes a reallocarrayfn.
Check for consistency between the queued destroy cells and the marked
circuit IDs. Check for consistency in the count of queued destroy
cells in several ways. Check to see whether any of the marked circuit
IDs have somehow been marked longer than the channel has existed.
Conflicts:
src/or/channel.c
src/or/circuitlist.c
src/or/connection.c
Conflicts involved removal of next_circ_id and addition of
unusable-circid tracking.
The point of the "idle timeout" for connections is to kill the
connection a while after it has no more circuits. But using "last
added a non-padding cell" as a proxy for that is wrong, since if the
last circuit is closed from the other side of the connection, we
will not have sent anything on that connection since well before the
last circuit closed.
This is part of fixing 6799.
When applied to 0.2.5, it is also a fix for 12023.
This was previously satisfied by using a temporary variable, but there
are three other instances in circuitlist.c that gcc is now bothered by,
so now introduce a CONST_TO_ORIGIN_CIRCUIT that takes a const
circuit_t instead.
If we fail in circuit_get_by_rend_token_and_purpose because the
circuit has no rend_info, don't try to reference fiends from its
rend_info when logging an error. Bugfix on 8b9a2cb68, which is
going into Tor 0.2.5.4-alpha.
A new set of unit test cases are provided, as well as introducing
an alternative paradigm and macros to support it. Primarily, each test
case is given its own namespace, in order to isolate tests from each
other. We do this by in the usual fashion, by appending module and
submodule names to our symbols. New macros assist by reducing friction
for this and other tasks, like overriding a function in the global
namespace with one in the current namespace, or declaring integer
variables to assist tracking how many times a mock has been called.
A set of tests for a small-scale module has been included in this
commit, in order to highlight how the paradigm can be used. This
suite gives 100% coverage to status.c in test execution.
Found by testing with chutney. The old behavior was "fail an
assertion", which obviously isn't optimal.
Bugfix on 8b9a2cb68b290e550695124d7ef0511225b451d5; bug not in any
released version.
In circuitlist_free_all, we free all the circuits, removing them from
the map as we go, but we weren't actually freeing the placeholder
entries that we use to indicate pending DESTROY cells.
Fix for bug 11278; bugfix on the 7912 code that was merged in
0.2.5.1-alpha
This contains the obvious implementation using the circuitmux data
structure. It also runs the old (slow) algorithm and compares
the results of the two to make sure that they're the same.
Needs review and testing.
In a couple of places, to implement the OOM-circuit-killer defense
against sniper attacks, we have counters to remember the age of
cells or data chunks. These timers were based on wall clock time,
which can move backwards, thus giving roll-over results for our age
calculation. This commit creates a low-budget monotonic time, based
on ratcheting gettimeofday(), so that even in the event of a time
rollback, we don't do anything _really_ stupid.
A future version of Tor should update this function to do something
even less stupid here, like employ clock_gettime() or its kin.
On busy servers, this function takes up something like 3-7% in
different profiles, and gets invoked every time we need to participate
as the midpoint in a hidden service.
So maybe walking through a linked list of all the circuits here wasn't
a good idea.
This patch splits out some of the functions in OOM handling so that
it's easier to check them without involving the rest of Tor or
requiring that the circuits be "wired up".
Right now this accounts for about 1% of circuits over all, but if you
pick a guard that's running 0.2.3, it will be about 6% of the circuits
running through that guard.
Making sure that every circuit has at least one ntor link means that
we're getting plausibly good forward secrecy on every circuit.
This implements ticket 9777,
Conflicts:
src/or/or.h
src/or/relay.c
Conflicts were simple to resolve. More fixes were needed for
compilation, including: reinstating the tv_to_msec function, and renaming
*_conn_cells to *_chan_cells.
Previously, when we ran low on memory, we'd close whichever circuits
had the most queued cells. Now, we close those that have the
*oldest* queued cells, on the theory that those are most responsible
for us running low on memory, and that those are the least likely to
actually drain on their own if we wait a little longer.
Based on analysis from a forthcoming paper by Jansen, Tschorsch,
Johnson, and Scheuermann. Fixes bug 9093.
There were only two functions outside of circuitstats that actually
wanted to know what was inside this. Making the structure itself
hidden should help isolation and prevent us from spaghettifying the
thing more.
This implements "algorithm 1" from my discussion of bug #9072: on OOM,
find the circuits with the longest queues, and kill them. It's also a
fix for #9063 -- without the side-effects of bug #9072.
The memory bounds aren't perfect here, and you need to be sure to
allow some slack for the rest of Tor's usage.
This isn't a perfect fix; the rest of the solutions I describe on
codeable.
I added the code to pass a destroy cell to a queueing function rather
than writing it immediately, and the code to remember that we
shouldn't reuse the circuit id until the destroy is actually sent, and
the code to release the circuit id once the destroy has been sent...
and then I finished by hooking destroy_cell_queue into the rest of
Tor.
Now that circid_t is 4 bytes long, the default integer promotions will
leave it alone when sizeof(int) == 4, which will leave us formatting an
unsigned as an int. That's technically undefined behavior.
Fixes bug 8447 on bfffc1f0fc. Bug not
in any released Tor.
In a number of places, we decrement timestamp_dirty by
MaxCircuitDirtiness in order to mark a stream as "unusable for any
new connections.
This pattern sucks for a few reasons:
* It is nonobvious.
* It is error-prone: decrementing 0 can be a bad choice indeed.
* It really wants to have a function.
It can also introduce bugs if the system time jumps backwards, or if
MaxCircuitDirtiness is increased.
So in this patch, I add an unusable_for_new_conns flag to
origin_circuit_t, make it get checked everywhere it should (I looked
for things that tested timestamp_dirty), and add a new function to
frob it.
For now, the new function does still frob timestamp_dirty (after
checking for underflow and whatnot), in case I missed any cases that
should be checking unusable_for_new_conns.
Fixes bug 6174. We first used this pattern in 516ef41ac1,
which I think was in 0.0.2pre26 (but it could have been 0.0.2pre27).
