Fortunately, our tor_free() is setting the variable to NULL after so we were
in a situation where NULL was always used instead of the transport name.
This first appeared in 894ff2dc84 and results in
basically no bridge with a transport being able to use DoS defenses.
Fixes#40345
Signed-off-by: David Goulet <dgoulet@torproject.org>
Clients now check whether their streams are attempting to re-enter
the Tor network (i.e. to send Tor traffic over Tor), and they close
them preemptively if they think exit relays will refuse them.
See bug 2667 for details. Resolves ticket 40271.
- Implement overload statistics structure.
- Implement function that keeps track of overload statistics.
- Implement function that writes overload statistics to descriptor.
- Unittest for the whole logic.
This option changes the time for which a bandwidth measurement period
must have been in progress before we include it when reporting our
observed bandwidth in our descriptors. Without this option, we only
consider a time period towards our maximum if it has been running
for a full day. Obviously, that's unacceptable for testing
networks, where we'd like to get results as soon as possible.
For non-testing networks, I've put a (somewhat arbitrary) 2-hour
minimum on the option, since there are traffic analysis concerns
with immediate reporting here.
Closes#40337.
We were looking for the first instance of "directory-signature "
when instead the correct behavior is to look for the first instance
of "directory-signature " at the start of a line.
Unfortunately, this can be exploited as to crash authorities while
they're voting.
Fixes#40316; bugfix on 0.2.2.4-alpha. This is TROVE-2021-002,
also tracked as CVE-2021-28090.
When reloading a service, we can re-register a service and thus end up again
in the metrics store initialization code path which is fine. No need to BUG()
anymore.
Fixes#40334
Signed-off-by: David Goulet <dgoulet@torproject.org>
Use find_str_at_start_of_line(), not strstr() here: we don't want
to match "MemTotal: " if it appears in the middle of a line.
Fixes#40315; bugfix on 0.2.5.4-alpha.
The directory_fetches_from_authorities() is used to know if a client or relay
should fetch data from an authority early in the boot process.
We had a condition in that function that made a relay trigger that fetch if it
didn't know its address (so we can learn it). However, when this is called,
the address discovery has not been done yet so it would always return true for
a relay.
Furthermore, it would always trigger a log notice that the IPv4 couldn't be
found which was inevitable because the address discovery process has not been
done yet (done when building our first descriptor).
It is also important to point out that starting in 0.4.5.1-alpha, asking an
authority for an address is done during address discovery time using a one-hop
circuit thus independent from the relay deciding to fetch or not documents
from an authority.
Small fix also is to reverse the "IPv(4|6)Only" flag in the notice so that if
we can't find IPv6 it would output to use IPv4Only.
Fixes#40300
Signed-off-by: David Goulet <dgoulet@torproject.org>
Fix a bug introduced in 94b56eaa75 which
overwrite the connection message line.
Furthermore, improve how we generate that line by using a smartlist and change
the format so it is clearer of what is being rejected/detected and, if
applicable, which option is disabled thus yielding no stats.
Closes#40308
Signed-off-by: David Goulet <dgoulet@torproject.org>
This is a new detection type which is that a relay can now control the rate of
client connections from a single address.
The mechanism is pretty simple, if the rate/burst is reached, the address is
marked for a period of time and any connection from that address is denied.
Closes#40253
Signed-off-by: David Goulet <dgoulet@torproject.org>
When trying to find our address to publish, we would log notice if we couldn't
find it from the cache but then we would look at the suggested cache (which
contains the address from the authorities) in which we might actually have the
address.
Thus that log notice was misplaced. Move it down after the suggested address
cache lookup.
Closes#40300
Signed-off-by: David Goulet <dgoulet@torproject.org>
It can be called with strings that should have been
length-delimited, but which in fact are not. This can cause a
CPU-DoS bug or, in a worse case, a crash.
Since this function isn't essential, the best solution for older
Tors is to just turn it off.
Fixes bug 40286; bugfix on 0.2.2.1-alpha when dump_desc() was
introduced.
Now that exit relays don't allow exit connections to directory authority
DirPorts, the follow-up step is to make directory authorities stop doing
DirPort reachability checks.
Fixes#40287
Signed-off-by: David Goulet <dgoulet@torproject.org>
Turns out, we forgot to add the METRICS connection type fo the finished
flushing handler.
Fixes#40295
Signed-off-by: David Goulet <dgoulet@torproject.org>
We were just looking at the family which is not correct because it is possible
to have two explicit ORPort for the same family but different addresses. One
example is:
ORPort 127.0.0.1:9001 NoAdvertise
ORPort 1.2.3.4:9001 NoListen
Thus, this patch now ignores ports that have different addresses iff they are
both explicits. That is, if we have this example, also two different
addresses:
ORPort 9001
ORPort 127.0.0.1:9001 NoAdvertise
The first one is implicit and second one is explicit and thus we have to
consider them for removal which in this case would remove the "ORPort 9001" in
favor of the second port.
Fixes#40289
Signe-off-by: David Goulet <dgoulet@torproject.org>
In other words, if PublishServerDescriptor is set to 0 and AssumeReachable to
1, then allow a relay to hold a RFC1918 address.
Reasons for this are documented in #40208Fixes#40208
Signed-off-by: David Goulet <dgoulet@torproject.org>
Handle the EOF situation for a metrics connection. Furthermore, if we failed
to fetch the data from the inbuf properly, mark the socket as closed because
the caller, connection_process_inbuf(), assumes that we did so on error.
Fixes#40257
Signed-off-by: David Goulet <dgoulet@torproject.org>
Previously we would warn in this case... but there's really no
justification for doing so, and it can only cause confusion.
Fixes bug #40281; bugfix on 0.4.0.1-alpha.
In two instances we must look at this flag:
1. When we build the descriptor so the IPv6 is NOT added to the descriptor in
case we judge that we need to omit the address but still publish.
2. When we are deciding if the descriptor is publishable. This flags tells us
that the IPv6 was not found reachable but we should still publish.
Fixes#40279
Signed-off-by: David Goulet <dgoulet@torproject.org>
Exit relays now reject exit attempts to known relay addresses + ORPort and
also to authorities on the ORPort and DirPort.
Closes#2667
Signed-off-by: David Goulet <dgoulet@torproject.org>
Exit relays now reject exit attempts to known relay addresses + ORPort and
also to authorities on the ORPort and DirPort.
Closes#2667
Signed-off-by: David Goulet <dgoulet@torproject.org>
We would before do an address discovery and then a lookup in the cache if not
found which is now simplified by calling relay_find_addr_to_publish() directly
which does all those combined.
Furthermore, by doing so, we won't trigger an address discovery every minute
if we have no ORPort configured for the family.
Fixes#40254
Signed-off-by: David Goulet <dgoulet@torproject.org>
Generates the compile_commands.json file using the "bear" application so the
ccls server can be more efficient with our code base.
Closes#40227
Signed-off-by: David Goulet <dgoulet@torproject.org>
This validation was only done if DisableNetwork was off because we would use
the global list of transports/bridges and DisableNetwork would not populate
it.
This was a problem for any user using DisableNetwork which includes Tor
Browser and thus leading to the Bug() warning.
Without a more in depth refactoring, we can't do this validation without the
global list.
The previous commit makes it that any connection to a bridge without a
transport won't happen thus we keep the security feature of not connecting to
a bridge without its corresponding transport.
Related to #40106
Signed-off-by: David Goulet <dgoulet@torproject.org>
This patch limits the number of items in the consensus diff cache to 64
on the Windows platform. Hopefully, this will allow us to investigate a
smarter fix while avoiding the situation reported in tor#24857 where
Windows relay operators report Tor using 100% CPU.
See: tor#24857
This patch removes a call to `tor_assert_nonfatal()` if
`extend_info_from_node()` returns NULL. This is unnecessary as we
already handle the case where `info` is NULL in the next `if (!info) {
... }` block in the code.
See: tor#32666.
This reverts commit d07f17f676.
We don't want to consider an entire routable IPv6 network as sybil if more
than 2 relays happen to be on it. For path selection it is very important but
not for selecting relays in the consensus.
Fixes#40243
We can end up trying to find our address from an authority while we don't have
yet its descriptor.
In this case, don't BUG() and just come back later.
Closes#40231
Signed-off-by: David Goulet <dgoulet@torproject.org>
This one should work on GCC _and_ on Clang. The previous version
made Clang happier by not having unreachable "fallthrough"
statements, but made GCC sad because GCC didn't think that the
unconditional failures were really unconditional, and therefore
_wanted_ a FALLTHROUGH.
This patch adds a FALLTHROUGH_UNLESS_ALL_BUGS_ARE_FATAL macro that
seems to please both GCC and Clang in this case: ordinarily it is a
FALLTHROUGH, but when ALL_BUGS_ARE_FATAL is defined, it's an
abort().
Fixes bug 40241 again. Bugfix on earlier fix for 40241, which was
merged into maint-0.3.5 and forward, and released in 0.4.5.3-rc.
Some gcc versions do explode if the order of the linker flags are not correct.
One issue was statically building OpenSSL which would require that "-lssl
-lcrypto" be put _before_ the "-lpthread -ldl" flags.
I have not such problem with GCC 10 but does with GCC 9.
Closes#33624
Signed-off-by: David Goulet <dgoulet@torproject.org>
Our original code for parsing these parameters out of our list of
parameters pre-dated us having the
dirvote_get_intermediate_param_value() function... and it was buggy.
Specifically, it would reject any " ... K=V ..." value
where there were additional unconverted characters after the V, and
use the default value instead,
We haven't run into this yet because we've never voted for
bwweightscale to be anything besides the default 10000, or
maxunmeasuredbw to be anything besides the default 20.
This requires a new consensus method because it is a change in how
consensuses are computed.
Fixes bug 19011; bugfix on 0.2.2.10-alpha.
Some days before this commit, the network experienced a DDoS on the directory
authorities that prevented them to generate a consensus for more than 5 hours
straight.
That in turn entirely disabled onion service v3, client and service side, due
to the subsystem requiring a live consensus to function properly.
We know require a reasonably live consensus which means that the HSv3
subsystem will to its job for using the best consensus tor can find. If the
entire network is using an old consensus, than this should be alright.
If the service happens to use a live consensus while a client is not, it
should still work because the client will use the current SRV it sees which
might be the previous SRV for the service for which it still publish
descriptors for.
If the service is using an old one and somehow can't get a new one while
clients are on a new one, then reachability issues might arise. However, this
is a situation we already have at the moment since the service will simply not
work if it doesn't have a live consensus while a client has one.
Fixes#40237
Signed-off-by: David Goulet <dgoulet@torproject.org>
We're getting "fallback annotation annotation in unreachable code"
warnings when we build with ALL_BUGS_ARE_FATAL. This patch fixes
that.
Fixes bug 40241. Bugfix on 0.3.5.4-alpha.
If we get an address suggestion from a directory authority and we have no
address configured or discovered, log it at notice level so the operator can
learn what address will be used by Tor.
Fixes#40201
Signed-off-by: David Goulet <dgoulet@torproject.org>
