This defense will cause Cisco, Juniper, Fortinet, and other routers operating
in the default configuration to collapse netflow records that would normally
be split due to the 15 second flow idle timeout.
Collapsing these records should greatly reduce the utility of default netflow
data for correlation attacks, since all client-side records should become 30
minute chunks of total bytes sent/received, rather than creating multiple
separate records for every webpage load/ssh command interaction/XMPP chat/whatever
else happens to be inactive for more than 15 seconds.
The defense adds consensus parameters to govern the range of timeout values
for sending padding packets, as well as for keeping connections open.
The defense only sends padding when connections are otherwise inactive, and it
does not pad connections used solely for directory traffic at all. By default
it also doesn't pad inter-relay connections.
Statistics on the total padding in the last 24 hours are exported to the
extra-info descriptors.
That log statement can be triggered if somebody on the Internet behaves badly
which is possible with buggy implementation for instance.
Fixes#21293
Signed-off-by: David Goulet <dgoulet@torproject.org>
This patch adds the `tor_compress_get_total_allocation()` which returns
an approximate number of bytes currently in use by all the different
compression backends.
See: https://bugs.torproject.org/21662
This patch refactors the `torgzip` module to allow us to extend a common
compression API to support multiple compression backends.
Additionally we move the gzip/zlib code into its own module under the
name `compress_zlib`.
See https://bugs.torproject.org/21664
When a client tried to connect to an invalid port of an hidden service, a
warning was printed:
[warn] connection_edge_process_relay_cell (at origin) failed.
This is because the connection subsystem wants to close the circuit because
the port can't be found and then returns a negative reason to achieve that.
However, that specific situation triggered a warning. This commit prevents it
for the specific case of an invalid hidden service port.
Fixes#16706
Signed-off-by: David Goulet <dgoulet@torproject.org>
This patch makes us store the number of sent and received RELAY_DATA
cells used for directory connections. We log the numbers after we have
received an EOF in connection_dir_client_reached_eof() from the
directory server.
This implements the proposal 224 directory descriptor cache store and lookup
functionalities. Furthermore, it merges the OOM call for the HSDir cache with
current protocol v2 and the new upcoming v3.
Add hs_cache.{c|h} with store/lookup API.
Closes#18572
Signed-off-by: David Goulet <dgoulet@torproject.org>
Signed-off-by: George Kadianakis <desnacked@riseup.net>
Not telling the cmux would sometimes cause an assertion failure in
relay.c when we tried to get an active circuit and found an "active"
circuit with no cells.
Additionally, replace that assert with a test and a log message.
Fix for bug 20203. This is actually probably a bugfix on
0.2.8.1-alpha, specifically my code in 8b4e5b7ee9 where I
made circuit_mark_for_close_() do less in order to simplify our call
graph. Thanks to "cypherpunks" for help diagnosing.
These functions were there so that we could abstract the differences
between evbuffer and buf_t. But with the bufferevent removal, this
no longer serves a purpose.
Every functions and objects that are used for hidden service descriptor
caches are moved to rendcache.{c|h}.
This commit does NOT change anything, just moving code around.
Fixes#16399
Signed-off-by: David Goulet <dgoulet@ev0ke.net>
We add a compression level argument to tor_zlib_new, and use it to
determine how much memory to allocate for the zlib object. We use the
existing level by default, but shift to smaller levels for small
requests when we have been over 3/4 of our memory usage in the past
half-hour.
Closes ticket 11791.
