This one can only be exploited if you can generate a correctly
signed consensus, so it's not as bad as 25074.
Fixes bug 25251; also tracked as TROVE-2018-004.
In some cases we had checked for it, but in others we had not. One
of these cases could have been used to remotely cause
denial-of-service against directory authorities while they attempted
to vote.
Fixes TROVE-2018-001.
Folks have found two in the past week or so; we may as well fix the
others.
Found with:
\#!/usr/bin/python3
import re
def findMulti(fname):
includes = set()
with open(fname) as f:
for line in f:
m = re.match(r'^\s*#\s*include\s+["<](\S+)[>"]', line)
if m:
inc = m.group(1)
if inc in includes:
print("{}: {}".format(fname, inc))
includes.add(m.group(1))
import sys
for fname in sys.argv[1:]:
findMulti(fname)
since all it does is produce false positives
this commit should get merged into 0.2.9 and 0.3.0 *and* 0.3.1, even
though the code in the previous commit is already present in 0.3.1. sorry
for the mess.
[Cherry-picked]
since all it does is produce false positives
this commit should get merged into 0.2.9 and 0.3.0 *and* 0.3.1, even
though the code in the previous commit is already present in 0.3.1. sorry
for the mess.
This commit takes a piece of commit af8cadf3a9 and a piece of commit
46fe353f25, with the goal of making channel_is_client() be based on what
sort of connection handshake the other side used, rather than seeing
whether the other side ever sent a create_fast cell to us.
Since 0.2.4, tor uses EWMA circuit policy to prioritize. The previous
algorithm, round-robin, hasn't been used since then but was still used as a
fallback.
Now that EWMA is mandatory, remove that code entirely and enforce a cmux
policy to be set.
This is part of a circuitmux cleanup to improve performance and reduce
complexity in the code. We'll be able to address future optimization with this
work.
Closes#25268
Signed-off-by: David Goulet <dgoulet@torproject.org>
The reason to do so is because these functions haven't been used in years so
since 0.2.4, every callsite is NOP.
In future commits, we'll remove the round robin circuit policy which is mostly
validated within those function.
This simplifies the code greatly and remove dead code for which we never had a
configure option in the first place nor an easy way to use them in production.
Part of #25268
Signed-off-by: David Goulet <dgoulet@torproject.org>
It is rename to something more meaningful that explains what it does exactly
which is sets the EWMA options (currently only one exists). The new name is
cmux_ewma_set_options().
Also, remove a public function from circuitmux_ewma.h that is only used in the
C file. Make it static inline as well.
Signed-off-by: David Goulet <dgoulet@torproject.org>
To achieve this, a default value for the CircuitPriorityHalflife option was
needed. We still look in the options and then the consensus but in case no
value can be found, the default CircuitPriorityHalflifeMsec=30000 is used. It
it the value we've been using since 0.2.4.4-alpha.
This means that EWMA, our only policy, can not be disabled anymore fallbacking
to the round robin algorithm. Unneeded code to control that is removed in this
commit.
Part of #25268
Signed-off-by: David Goulet <dgoulet@torproject.org>
We had this safeguard around dos_init() but not when the consensus changes
which can modify consensus parameters and possibly enable the DoS mitigation
even if tor wasn't a public relay.
Fixes#25223
Signed-off-by: David Goulet <dgoulet@torproject.org>
Explicitly inform the operator of the rejected relay to set a valid email
address in the ContactInfo field and contact bad-relays@ mailing list.
Fixes#25170
Signed-off-by: David Goulet <dgoulet@torproject.org>
This is to avoid positively identifying Exit relays if tor client connection
comes from them that is reentering the network.
One thing to note is that this is done only in the DoS subsystem but we'll
still add it to the geoip cache as a "client" seen. This is done that way so
to avoid as much as possible changing the current behavior of the geoip client
cache since this is being backported.
Closes#25193
Signed-off-by: David Goulet <dgoulet@torproject.org>
Explicitly inform the operator of the rejected relay to set a valid email
address in the ContactInfo field and contact bad-relays@ mailing list.
Fixes#25170
Signed-off-by: David Goulet <dgoulet@torproject.org>
At this commit, the SocksSocketsGroupWritable option is renamed to
UnixSocksGroupWritable. A deprecated warning is triggered if the old option is
used and tor will use it properly.
Fixes#24343
Signed-off-by: David Goulet <dgoulet@torproject.org>
Remove a series of connection counters that were only used when dumping the
rephist statistics with SIGUSR1 signal.
This reduces the or_history_t structure size.
Closes#25163
Signed-off-by: David Goulet <dgoulet@torproject.org>
This removes the code that tracks the extend attemps a client makes. We don't
use it and it was only used to provide statistics on a SIGUSR1 from the
rephist dump stats function.
Part of #25163
Signed-off-by: David Goulet <dgoulet@torproject.org>
Services can keep rendezvous circuits for a while so don't log them if tor is
a single onion service.
Fixes#25116
Signed-off-by: David Goulet <dgoulet@torproject.org>
The HT_FOREACH() is insanely heavy on the CPU and this is part of the fast
path so make it return the nice memory size counter we added in
4d812e29b9.
Fixes#25148
Signed-off-by: David Goulet <dgoulet@torproject.org>
Included crypto_digest.h in some files in order to solve xof+digest module
dependency issues. Removed crypto.h where it isn't needed anymore.
Follows #24658.
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Becasue the circuit creation burst and rate can change at runtime it is
possible that between two refill of a bucket, we end up setting the bucket
value to less than there currently is.
Fixes#25128
Signed-off-by: David Goulet <dgoulet@torproject.org>
If the cache is using 20% of our maximum allowed memory, clean 10% of it. Same
behavior as the HS descriptor cache.
Closes#25122
Signed-off-by: David Goulet <dgoulet@torproject.org>
The current code flow makes it that we can release a channel in a PENDING
state but not in the pending list. This happens while the channel is being
processed in the scheduler loop.
Fixes#25125
Signed-off-by: David Goulet <dgoulet@torproject.org>
The accurate address of a connection is real_addr, not the addr member.
channel_tls_get_remote_addr_method() now returns real_addr instead.
Fixes#24952; bugfix on 707c1e2 in 0.2.4.11-alpha.
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
Tor preemptiely builds circuits and they can be cannibalized later in their
lifetime. A Guard node can become unusable (from our guard state) but we can
still have circuits using that node opened. It is important to not pick those
circuits for any usage through the cannibalization process.
Fixes#24469
Signed-off-by: David Goulet <dgoulet@torproject.org>
These are no longer meaningful, since there's no longer an upper
limit to how many times (in the exponential-backoff world) one can
retry a download. download_status_is_ready() didn't check these any
more, and neither do we.
In 0.3.2.1-alpha, we've added notify_networkstatus_changed() in order to have
a way to notify other subsystems that the consensus just changed. The old and
new consensus are passed to it.
Before this patch, this was done _before_ the new consensus was set globally
(thus NOT accessible by getting the latest consensus). The scheduler
notification was assuming that it was set and select_scheduler() is looking at
the latest consensus to get the parameters it might needs. This was very wrong
because at that point it is still the old consensus set globally.
This commit changes the notify_networkstatus_changed() to be the "before"
function and adds an "after" notification from which the scheduler subsystem
is notified.
Fixes#24975
When we stopped looking at the "protocols" variable directly, we
broke the hs_service/build_update_descriptors test, since it didn't
actually update any of the flags.
The fix here is to call summarize_protover_flags() from that test,
and to expose summarize_protover_flags() as "STATIC" from
routerparse.c.
This is the quick fix that is keeping the channel in PENDING state so if we
ever try to reschedule the same channel, it won't happened.
Fixes#24700
Signed-off-by: David Goulet <dgoulet@torproject.org>
It is possible in normal circumstances that a client fetches a descriptor
that has a lower revision counter than the one in its cache. This can happen
due to HSDir desync.
Fixes#24976
Signed-off-by: David Goulet <dgoulet@torproject.org>
Setting the default for this at 10 and the learning timeout to 3 minutes means
we will complete our cbt learning in 30 minutes, which is under the reduced
padding connection timeout window.
In 0.3.2.1-alpha, we've added this function in order to have a way to notify
other subsystems that the consensus just changed. The old consensus and the
new one are passed to it.
Before this patch, this was done _before_ the new consensus was set globally
(thus NOT accessible by getting the latest consensus). The scheduler
notification was assuming that it was set and select_scheduler() is looking at
the latest consensus to get the parameters it might needs. This was very wrong
because at that point it is still the old consensus set globally.
With this commit, notify_networkstatus_changed() has been moved _after_ the
new consensus is set globally. The main obvious reasons is to fix the bug
described above and in #24975. The other reason is that this notify function
doesn't return anything which could be allowing the possibility of refusing to
set the new consensus on error. In other words, the new consensus is set right
after the notification whatever happens.
It does no harm or change in behavior to set the new consensus first and then
notify the subsystems. The two functions currently used are for the control
port using the old and new consensus and sending the diff. The second is the
scheduler that needs the new consensus to be set globally before being called.
Of course, the function has been documented accordinly to clearly state it is
done _after_ the new consensus is set.
Fixes#24975
Signed-off-by: David Goulet <dgoulet@torproject.org>
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.
