The C code and the rust code had different separate integer overflow
bugs here. That suggests that we're better off just forbidding this
pathological case.
Also, add tests for expected behavior on receiving a bad protocol
list in a consensus.
Fixes another part of 25249.
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.
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.
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>
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".
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>
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>
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.
