Stop adding unneeded channel padding right after we finish flushing
to a connection that has been trying to flush for many seconds.
Instead, treat all partial or complete flushes as activity on the
channel, which will defer the time until we need to add padding.
This fix should resolve confusing and scary log messages like
"Channel padding timeout scheduled 221453ms in the past."
Fixes bug 22212; bugfix on 0.3.1.1-alpha.
I think technically we could resolve bug 22212 by adding a call to
channel_timestamp_active() only in the finished_flushing case. But I added
a call in the flushed_some case too since that seems to more accurately
reflect the notion of "active".
Using get_uptime() and reset_uptime() instead of
accessing stats_n_seconds_working directly.
stats_n_seconds_working is not extern anymore.
Ticket #25081
Because this touches too many commits at once, it is made into one single
commit.
Remove the use of "tenths" for the circuit rate to simplify things. We can
only refill the buckets at best once every second because of the use of
approx_time() and our token system is set to be 1 token = 1 circuit so make
the rate a flat integer of circuit per second.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Imagine this scenario. We had 10 connections over the 24h lifetime of a geoip
cache entry. The lifetime of the entry has been reached so it is about to get
freed but 2 connections remain for it. After the free, a third connection
comes in thus making us create a new geoip entry for that address matching the
2 previous ones that are still alive. If they end up being closed, we'll have
a concurrent count desynch from what the reality is.
To mitigate this probably very rare scenario in practice, when we free a geoip
entry and it has a concurrent count above 0, we'll go over all connections
matching the address and clear out the tracked flag. So once they are closed,
we don't try to decrement the count.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This option refuses any ESTABLISH_RENDEZVOUS cell arriving from a client
connection. Its default value is "auto" for which we can turn it on or off
with a consensus parameter. Default value is 0.
Signed-off-by: David Goulet <dgoulet@torproject.org>
If the client address was detected as malicious, apply a defense which is at
this commit to return a DESTROY cell.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Add a function that notifies the DoS subsystem that a new CREATE cell has
arrived. The statistics are updated accordingly and the IP address can also be
marked as malicious if it is above threshold.
At this commit, no defense is applied, just detection with a circuit creation
token bucket system.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Implement a basic connection tracking that counts the number of concurrent
connections when they open and close.
This commit also adds the circuit creation mitigation data structure that will
be needed at later commit to keep track of the circuit rate.
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>
I'm leaving the getsockname code in transproxy alone, since it is
comparatively isolated, rather platform-specific, and hard to test.
Implements 18105.
The upcoming DoS mitigation subsytem needs to keep information on a per-IP
basis which is also what the geoip clientmap does.
For another subsystem to access that clientmap, this commit adds a lookup
function that returns the entry. For this, the clientmap_entry_t had to be
moved to the header file.
Signed-off-by: David Goulet <dgoulet@torproject.org>
We'd been using crypto_digest_dup() and crypto_digest_assign() here,
but they aren't necessary. Instead we can just use the stack to
store the previous state of the SHA_CTX and avoid a malloc/free pair.
Closes ticket 24914.
In order to make the OR and dir checking functions in router.c less confusing
we renamed some functions and splitted consider_testing_reachability() into
router_should_check_reachability() and router_do_reachability_checks(). Also we
improved the documentation.
Fixes#18918.
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Previously, we wouldn't do this when running with a routerinfo_t in
some cases, leading to many needless calls to the protover module.
This change also cleans up the code in nodelist.c a bit.
Fixes bug 25008; bugfix on 0.2.9.4-alpha.
For 23847, we want Tor to be able to shut down and then restart in
the same process. Here's a patch to make the Tor binary do that.
To test it, you need to build with --enable-restart-debugging, and
then you need to set the environment variable TOR_DEBUG_RESTART.
With this option, Tor will then run for 5 seconds, then restart
itself in-process without exiting. This only happens once.
You can change the 5-second interval using
TOR_DEBUG_RESTART_AFTER_SECONDS.
Implements ticket 24583.
Fix an "off by 2" error in counting rendezvous failures on the onion
service side.
While we thought we would stop the rendezvous attempt after one failed
circuit, we were actually making three circuit attempts before giving up.
Fixes bug 24895; bugfix on 0.0.6.
Fix a set of false positives where relays would consider connections
to other relays as being client-only connections (and thus e.g.
deserving different link padding schemes) if those relays fell out
of the consensus briefly.
Now we look only at the initial handshake and whether the connection
authenticated as a relay.
Fixes bug 24898; bugfix on 0.3.1.1-alpha.
New-style (v3) onion services now obey the "max rendezvous circuit
attempts" logic.
Previously they would make as many rendezvous circuit attempts as they
could fit in the MAX_REND_TIMEOUT second window before giving up.
Fixes bug 24894; bugfix on 0.3.2.1-alpha.
Define TOR_PRIuSZ as minGW compiler doesn't support zu format specifier for
size_t type.
Fixes#24861 on ac9eebd.
Signed-off-by: Fernando Fernandez Mancera <ffernandezmancera@gmail.com>
If we tried to move a descriptor from routerlist->old_routers
back into the current routerlist, we were preparing a buffer with
format_iso_time() on ri->cert_expiration_time, and doing it preemptively
since router_add_to_routerlist() might free ri so we wouldn't be able
to get at it later in the function.
But if the descriptor we're moving doesn't have any ed signature, then
its cert will be marked to expire at TIME_MAX, and handing TIME_MAX
to format_iso_time() generates this log warning:
correct_tm(): Bug: gmtime(9223372036854775807) failed with error Value too large for defined data type: Rounding down to 2037
The fix is to preemptively remember the expiry time, but only prepare
the buffer if we know we're going to need it.
Bugfix on commit a1b0a0b9, which came about as part of a fix for bug
20020, and which is not yet in any released version of Tor (hence no
changes file).
Using this script:
sed -i.bak $'s|^,$|/* ===== */\\\n,|' src/or/fallback_dirs.inc
(Due to embedded newlines, this script only works in bash.)
And manually add a delimiter to the end of the header, and the start of
the fallback list.
This allows us to check that the code compiles, and the unit tests pass.
And it allows downstream users stem and atlas to adapt to the new format.
The upcoming fallback rebuild will automatically generate this new format.
Follow-up to 24725.
Using this script:
sed -i.bak $'s|^,$|/* extrainfo=0 */\\\n,|' src/or/fallback_dirs.inc
(Due to embedded newlines, this script only works in bash.)
This allows us to check that the code compiles, and the unit tests pass.
And it allows downstream users stem and atlas to adapt to the new format.
The upcoming fallback rebuild will automatically generate this new format,
with actual relay extrainfo cache flags.
Follow-up to 22759.
Using this script:
sed -i.bak $'s|^,$|/* nickname= */\\\n,|' src/or/fallback_dirs.inc
(Due to embedded newlines, this script only works in bash.)
This allows us to check that the code compiles, and the unit tests pass.
And it allows downstream users stem and atlas to adapt to the new format.
The upcoming fallback rebuild will automatically generate this new format,
with actual relay nicknames.
Follow-up to 24600.
Using this script:
sed -i.bak 's/" weight=10",/,/' src/or/fallback_dirs.inc
This allows us to check that the code compiles, and the unit tests pass.
And it allows downstream users stem and atlas to adapt to the new format.
The upcoming fallback rebuild will automatically generate this new format.
Follow-up to 24679.
These are all about local variables shadowing global
functions. That isn't normally a problem, but at least one
compiler we care about seems to treat this as a case of -Wshadow
violation, so let's fix it.
Fixes bug 24634; bugfix on 0.3.2.1-alpha.
Tor now sets IPv6 preferences on rewrite_node_address_for_bridge() even if
there is only ri or rs. It always warns about them.
Also Tor now sets the IPv6 address in rs as well as it sets the one in ri.
Fixes#24572 on 9e9edf7 in 0.2.4.5-alpha.
Fixes#24573 on c213f27 in 0.2.8.2-alpha.
Signed-off-by: Fernando Fernandez Mancera <ffernandezmancera@gmail.com>
When the fascist_firewall_choose_address_ functions don't find a
reachable address, set the returned address to the null address and port.
This is a precautionary measure, because some callers do not check the
return value.
Fixes bug 24736; bugfix on 0.2.8.2-alpha.
This makes clients on the public tor network prefer to bootstrap off fallback
directory mirrors.
This is a follow-up to 24679, which removed weights from the default fallbacks.
Implements ticket 24681.
We've been seeing problems with destroy cells queues taking up a
huge amount of RAM. We can mitigate this, since while a full packed
destroy cell takes 514 bytes, we only need 5 bytes to remember a
circuit ID and a reason.
Fixes bug 24666. Bugfix on 0.2.5.1-alpha, when destroy cell queues
were introduced.
With extra_space negative, it means that the "notsent" queue is quite large so
we must consider that value with the current computed tcp_space. If we end up
to have negative space, we should not add more data to the kernel since the
notsent queue is just too filled up.
Fixes#24665
Signed-off-by: David Goulet <dgoulet@torproject.org>
Instead of using INT_MAX as a write limit for KISTLite, use the lower layer
limit which is using the specialized num_cells_writeable() of the channel that
will down the line check the connection's outbuf and limit it to 32KB
(OR_CONN_HIGHWATER).
That way we don't take the chance of bloating the connection's outbuf and we
keep the cells in the circuit queue which our OOM handler can take care of,
not the outbuf.
Finally, this commit adds a log_debug() in the update socket information
function of KIST so we can get the socket information in debug.
Fixes#24671
Signed-off-by: David Goulet <dgoulet@torproject.org>
Exposing cell_queues_get_total_allocation(), buf_get_total_allocation(),
tor_compress_get_total_allocation(), tor_compress_get_total_allocation() when
hit MaxMemInQueues threshold.
Fixes#24501
Signed-off-by: Fernando Fernandez Mancera <ffernandezmancera@gmail.com>
This patch adds support for MainloopStats that allow developers to get
main event loop statistics via Tor's heartbeat status messages. The new
status log message will show how many succesful, erroneous, and idle
event loop iterations we have had.
See: https://bugs.torproject.org/24605
Adding tor_remove_file(filename) and refactoring tor_cleanup().
Removing CookieAuthFile and ExtORPortCookieAuthFile when tor_cleanup() is
called.
Fixes#23271.
Signed-off-by: Fernando Fernandez Mancera <ffernandezmancera@gmail.com>
Using absolute_msec requires a 64-bit division operation every time
we calculate it, which gets expensive on 32-bit architectures.
Instead, just use the lazy "monotime_coarse_get()" operation, and
don't convert to milliseconds until we absolutely must.
In this case, it seemed fine to use a full monotime_coarse_t rather
than a truncated "stamp" as we did to solve this problem for the
timerstamps in buf_t and packed_cell_t: There are vastly more cells
and buffer chunks than there are channels, and using 16 bytes per
channel in the worst case is not a big deal.
There are still more millisecond operations here than strictly
necessary; let's see any divisions show up in profiles.
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.
When entry_list_is_constrained() is true, guards_retry_optimistic()
always returns true.
When entry_list_is_constrained() is false,
options->UseBridges is always false,
therefore !options->UseBridges is always true,
therefore (!options->UseBridges || ...) is always true.
Cleanup after #24367.
Commit e80893e51b made tor call
hs_service_intro_circ_has_closed() when we mark for close a circuit.
When we cleanup intro points, we iterate over the descriptor's map of intro
points and we can possibly mark for close a circuit. This was problematic
because we would MAP_DEL_CURRENT() the intro point then free it and finally
mark for close the circuit which would lookup the intro point that we just
free in the map we are iterating over.
This can't be done and leads to a use-after-free because the intro point will
be returned successfully due to the fact that we are still in the loop
iterating. In other words, MAP_DEL_CURRENT() followed by a digest256map_get()
of the same object should never be done in the same loop.
Fixes#24595
Signed-off-by: David Goulet <dgoulet@torproject.org>
In KIST, we could have a small congestion window value than the unacked
packets leading to a integer overflow which leaves the tcp_space value to be
humongous.
This has no security implications but it results in KIST scheduler allowing to
send cells on a potentially saturated connection.
Found by #24423. Fixes#24590.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This function leaks memory when the event_base is freed before the
event itself fires. That's not harmful, but it's annoying when
trying to debug other memory leaks.
Fixes bug 24584; bugfix on 0.2.8.1-alpha.
When we didn't do this before, we'd have some still-reachable memory
warnings, and we'd find ourselves crashing when we tried to
reinitialize libevent.
Part of 24581 (don't crash when restarting Tor in-process)
This patch adds support for Android's logging subsystem in Tor. When
debugging Android applications it is useful to be able to collect
information about the application running on the platform via the
various system services that is available on the platform.
This patch allows you to add "Log notice android" to your torrc and have
Tor send everything above and including the notice severity to Android's
ring buffer which can be inspected using the 'adb logcat' program.
See: https://bugs.torproject.org/24362
This patch ensures that we more easily can extend our log backends that
does not take any additional argument other than a single keyword. This
patch is mostly reindentation of some code which is why it is split out
into its own patch.
See: https://bugs.torproject.org/24362
Also make IPv6-only clients wait for microdescs for relays, even if we were
previously using descriptors (or were using them as a bridge) and have
a cached descriptor for them.
But if node_is_a_configured_bridge(), stop waiting for its IPv6 address in
a microdescriptor, because we'll never use it.
Implements #23827.
networkstatus_consensus_has_ipv6() tells us whether the consensus method of
our current consensus supports IPv6 ORPorts in the consensus.
Part of #23827.
This commit was made mechanically by this perl script:
\#!/usr/bin/perl -w -i -p
next if /^#define FREE_AND_NULL/;
s/\bFREE_AND_NULL\((\w+),/FREE_AND_NULL\(${1}_t, ${1}_free_,/;
s/\bFREE_AND_NULL_UNMATCHED\(/FREE_AND_NULL\(/;
Couple things happen in this commit. First, we do not re-queue a cell back in
the circuit queue if the write packed cell failed. Currently, it is close to
impossible to have it failed but just in case, the channel is mark as closed
and we move on.
The second thing is that the channel_write_packed_cell() always took ownership
of the cell whatever the outcome. This means, on success or failure, it needs
to free it.
It turns out that that we were using the wrong free function in one case and
not freeing it in an other possible code path. So, this commit makes sure we
only free it in one place that is at the very end of
channel_write_packed_cell() which is the top layer of the channel abstraction.
This makes also channel_tls_write_packed_cell_method() return a negative value
on error.
Two unit tests had to be fixed (quite trivial) due to a double free of the
packed cell in the test since now we do free it in all cases correctly.
Part of #23709
Signed-off-by: David Goulet <dgoulet@torproject.org>
Split hs_circuitmap_get_rend_circ_client_side(). One returns only established
circuits (hs_circuitmap_get_established_rend_circ_client_side()) and the other
returns all kinds of circuits.
Fixes#23459
Signed-off-by: Fernando Fernandez Mancera <ffernandezmancera@gmail.com>
Previously, circuit_stream_is_being_handled incorrectly reported
that (1) an exit port was "handled" by a circuit regardless of
whether the circuit was already isolated in some way, and
(2) that a stream could be "handled" by a circuit even if their
isolation settings were incompatible.
As a result of (1), in Tor Browser, circuit_get_unhandled_ports was
reporting that all ports were handled even though all non-internal
circuits had already been isolated by a SOCKS username+password.
Therefore, circuit_predict_and_launch_new was declining to launch
new exit circuits. Then, when the user visited a new site in Tor
Browser, a stream with new SOCKS credentials would be initiated,
and the stream would have to wait while a new circuit with those
credentials could be built. That wait was making the
time-to-first-byte longer than it needed to be.
Now, clean, not-yet-isolated circuit(s) will be automatically
launched ahead of time and be ready for use whenever a new stream
with new SOCKS credentials (or other isolation criteria) is
initiated.
Fixes bug 18859. Thanks to Nick Mathewson for improvements.
This patch adds a check for the return value of `hs_parse_address()` in
`hs_control_hspost_command()`. Since it should not be possible for
`hs_parse_address()` to fail in this context we wrap the error check
with the `BUG()` macro.
See: https://bugs.torproject.org/24543
