Values greater than 100 would have had the same effect as 100, so
this doesn't actually change Tor's behavior; it just makes the
intent clearer. Fixes#40486; see also torspec#66.
This is the loudest of our LOG_PROTOCOL_WARN messages, it can occur
naturally, and there doesn't seem to be a great response to it.
Partial fix for 40400; bugfix on 0.1.1.13-alpha.
This one happens every time we get a failure from
circuit_receive_relay_cell -- but for all the relevant failing cases
in that function, we already log in that function.
This resolves one case of #40400. Two cases remain.
Series 0.4.2.x, 0.4.3.x and 0.4.4.x will all be rejected at the
authority level at this commit.
Futhermore, the 0.4.5.x alphas and rc will also be rejected.
Closes#40480
Signed-off-by: David Goulet <dgoulet@torproject.org>
Coverity report: CID 1492322
________________________________________________________________________________________________________
*** CID 1492322: Integer handling issues (OVERFLOW_BEFORE_WIDEN)
/src/core/or/congestion_control_flow.c: 399 in circuit_process_stream_xon()
393 }
394
395 log_info(LD_EDGE, "Got XON: %d", xon->kbps_ewma);
396
397 /* Adjust the token bucket of this edge connection with the drain rate in
398 * the XON. Rate is in bytes from kilobit (kpbs). */
>>> CID 1492322: Integer handling issues (OVERFLOW_BEFORE_WIDEN)
>>> Potentially overflowing expression "xon_cell_get_kbps_ewma(xon) * 1000U" with type "unsigned int" (32 bits, unsigned) is evaluated using 32-bit arithmetic, and then used in a context that expects an expression of type "uint64_t" (64 bits, unsigned).
399 uint64_t rate = xon_cell_get_kbps_ewma(xon) * 1000;
400 if (rate == 0 || INT32_MAX < rate) {
401 /* No rate. */
402 rate = INT32_MAX;
403 }
404 token_bucket_rw_adjust(&conn->bucket, (uint32_t) rate, (uint32_t) rate);
Fixes#40478
Signed-off-by: David Goulet <dgoulet@torproject.org>
Fixes issue #22469 where port strings such as '0x00' get accepted, not
because the string gets converted to hex, but because the string is
silently truncated past the invalid character 'x'. This also causes
issues for strings such as '0x01-0x02' which look like a hex port range,
but in reality gets truncated to '0', which is definitely not what a
user intends.
Warn and reject such port strings as invalid.
Also, since we're throwing that "malformed port" warning a lot in the
function, wrap it up in a nice goto.
Fixes#22469
The connection_ap_attach_pending() function processes all pending
streams in the pending_entry_connections list. It first copy the pointer
and then allocates a brand new empty list.
It then iterates over that copy pointer to try to attach entry
connections onto any fitting circuits using
connection_ap_handshake_attach_circuit().
That very function, for onion service, can lead to flagging _all_
streams of the same onion service to be put in state RENDDESC_WAIT from
CIRCUIT_WAIT. By doing so, it also tries to remove them from the
pending_entry_connections but at that point it is already empty.
Problem is that the we are iterating over the previous
pending_entry_connections which contains the streams that have just
changed state and are no longer in CIRCUIT_WAIT.
This lead to this bug warning occuring a lot on busy services:
May 01 08:55:43.000 [warn] connection_ap_attach_pending(): Bug:
0x55d8764ae550 is no longer in circuit_wait. Its current state is
waiting for rendezvous desc. Why is it on pending_entry_connections?
(on Tor 0.4.4.0-alpha-dev )
This fix is minimal and basically allow a state to be not CIRCUIT_WAIT
and move on to the next one without logging a warning. Because the
pending_entry_connections is emptied before processing, there is no
chance for a streams to be stuck there forever thus it is OK to ignore
streams not in the right state.
Fixes#34083
Signed-off-by: David Goulet <dgoulet@torproject.org>
We only need to rate limit reading on edges for flow control, as per the rate
that comes in the XON from the other side. When we rate limit reading from the
edge source to this rate, we will only deliver that fast to the other side,
thus satisfying its rate request.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Relay do not accept both stores and lookups of version 2 descriptor.
This effectively disable version 2 HSDir supports for relays.
Part of #40476
Signed-off-by: David Goulet <dgoulet@torproject.org>
Upon receiving a v2 introduction request, the relay will close the
circuit and send back a tor protocol error.
Part of #40476
Signed-off-by: David Goulet <dgoulet@torproject.org>
The minimum service version is raised from 2 to 3 which effectively
disable loading or creating an onion service v2.
As for ADD_ONION, for version 2, a 551 error is returned:
"551 Failed to add Onion Service"
Part of #40476
Signed-off-by: David Goulet <dgoulet@torproject.org>
This effectively turns off the ability of tor to use HSv2 as a client by
invalidating the v2 onion hostname passed through a SOCKS request.
Part of #40476
Signed-off-by: David Goulet <dgoulet@torproject.org>
When building with --enable-fragile-hardening, add or relax Linux
seccomp rules to allow AddressSanitizer to execute normally if the
process terminates with the sandbox active.
Further resolves issue 11477.
We currently assume that the only way for Tor to listen on ports in the
privileged port range (1 to 1023), on Linux, is if we are granted the
NET_BIND_SERVICE capability. Today on Linux, it's possible to specify
the beginning of the unprivileged port range using a sysctl
configuration option. Docker (and thus the CI service Tor uses) recently
changed this sysctl value to 0, which causes our tests to fail as they
assume that we should NOT be able to bind to a privileged port *without*
the NET_BIND_SERVICE capability.
In this patch, we read the value of the sysctl value via the /proc/sys/
filesystem iff it's present, otherwise we assume the default
unprivileged port range begins at port 1024.
See: tor#40275
This code is based directly on the specification, without looking at
the reference implementation or the implementation in Arti.
Nonetheless, it is now passing with the test vectors generated by
the reference implementation.
When a directory request fails, we flag the relay as non Running so we
don't use it anymore.
This can be problematic with onion services because there are cases
where a tor instance could have a lot of services, ephemeral ones, and
keeps failing to upload descriptors, let say due to a bad network, and
thus flag a lot of nodes as non Running which then in turn can not be
used for circuit building.
This commit makes it that we never flag nodes as non Running on a onion
service directory request (upload or fetch) failure as to keep the
hashring intact and not affect other parts of tor.
Fortunately, the onion service hashring is _not_ selected by looking at
the Running flag but since we do a 3-hop circuit to the HSDir, other
services on the same instance can influence each other by removing nodes
from the consensus for path selection.
This was made apparent with a small network that ran out of nodes to
used due to rapid succession of onion services uploading and failing.
See #40434 for details.
Fixes#40434
Signed-off-by: David Goulet <dgoulet@torproject.org>
Fixes bug 40078.
As reported by hdevalence our batch verification logic can cause an assert
crash.
The assert happens because when the batch verification of ed25519-donna fails,
the code in `ed25519_checksig_batch()` falls back to doing a single
verification for each signature.
The crash occurs because batch verification failed, but then all signatures
individually verified just fine.
That's because batch verification and single verification use a different
equation which means that there are sigs that can pass single verification
but fail batch verification.
Fixing this would require modding ed25519-donna which is not in scope for
this ticket, and will be soon deprecated in favor of arti and
ed25519-dalek, so my branch instead removes batch verification.
Now the circuits look like this:
client rend: C -> G -> L2 -> Rend
client intro: C -> G -> L2 -> M -> Intro
client hsdir: C -> G -> L2 -> M -> HSDir
service rend: C -> G -> L2 -> M -> Rend
service intro: C -> G -> L2 -> M -> Intro
service hsdir: C -> G -> L2 -> M -> HSDir
Bridge operators should generally publish their descriptors except for
rare cases, and instead use the BridgeDistribution none setting to
prevent their bridge from being distributed by BridgeDB.
Continue having a tor_gmtime_impl() unit test so that we can detect
any problems in our replacement function; add a new test function to
make sure that gmtime<->timegm are a round-trip on now-ish times.
This is a fix for bug #40383, wherein we ran into trouble because
tor_timegm() does not believe that time_t should include a count of
leap seconds, but FreeBSD's gmtime believes that it should. This
disagreement meant that for a certain amount of time each day,
instead of calculating the most recent midnight, our voting-schedule
functions would calculate the second-most-recent midnight, and lead
to an assertion failure.
I am calling this a bugfix on 0.2.0.3-alpha when we first started
calculating our voting schedule in this way.
My clang doesn't like it when we write code like this:
char *list[] = {
"abc",
"def",
"ghi"
"jkl"
}
It wonders whether we meant to put a comma between "ghi" and "jkl"
or not, and gives a warning.
To suppress this warning (since in this case, we did mean to omit
the comma), we just wrap the two strings in parentheses.
Closes#40426; bugfix on 0.4.0.4-rc.
We already did this in a couple of places, but there are more that
we didn't get. This is necessary for systems with versions of
NSS that don't do their prototypes properly.
Fixes#40409; bugfix on 0.3.5.1-alpha.
This patch enables the deterministic RNG for address set tests,
including the tests which uses address set indirectly via the nodelist
API.
This should prevent random test failures in the highly unlikely case of
a false positive which was seen in tor#40419.
See: tpo/core/tor#40419.
This issue was reported by Jann Horn part of Google's Project Zero.
Jann's one-sentence summary: entry/middle relays can spoof RELAY_END cells on
half-closed streams, which can lead to stream confusion between OP and
exit.
Fixes#40389
Previously, we would detect errors from a missing RNG
implementation, but not failures from the RNG code itself.
Fortunately, it appears those failures do not happen in practice
when Tor is using OpenSSL's default RNG implementation. Fixes bug
40390; bugfix on 0.2.8.1-alpha. This issue is also tracked as
TROVE-2021-004. Reported by Jann Horn at Google's Project Zero.
Without this message getting logged at 'WARN', it's hard to
contextualize the messages we get about compression bombs, so this
message should fix#40175.
I'm rate-limiting this, however, since it _could_ get spammy if
somebody on the network starts acting up. (Right now it should be
very quiet; I've asked Sebastian to check it, and he says that he
doesn't hit this message in practice.)
Closes#40175.
Cached_dir_t is a somewhat "legacy" kind of storage when used for
consensus documents, and it appears that there are cases when
changing our settings causes us to stop updating those entries.
This can cause trouble, as @arma found out in #40375, where he
changed his settings around, and consensus diff application got
messed up: consensus diffs were being _requested_ based on the
latest consensus, but were being (incorrectly) applied to a
consensus that was no longer the latest one.
This patch is a minimal fix for backporting purposes: it has Tor do
the same search when applying consensus diffs as we use to request
them. This should be sufficient for correct behavior.
There's a similar case in GETINFO handling; I've fixed that too.
Fixes#40375; bugfix on 0.3.1.1-alpha.
When seccomp sandbox is active, SAVECONF failed because it was not
able to save the backup files for torrc. This commit simplifies
the implementation of SAVECONF and sandbox by making it keep only
one backup of the configuration file.
Current counters are reset every heartbeat. This commit adds two
counters for the assigned and dropped onionskins that are not reset so
they can be exported onto the MetricsPort.
Closes#40387
Signed-off-by: David Goulet <dgoulet@torproject.org>
The connection type for the listener part was missing from the "is
connection a listener" function.
This lead to our periodic event that retries our listeners to keep
trying to bind() again on an already opened MetricsPort.
Closes#40370
Signed-off-by: David Goulet <dgoulet@torproject.org>
This resulted in the labels not being surrounded by double quotes and
thus Prometheus not liking it.
Signed-off-by: David Goulet <dgoulet@torproject.org>
Emit on the MetricsPort all the DNS statistics we have that is the total
number of queries seen and errors per record type.
Related to #40367
Signed-off-by: David Goulet <dgoulet@torproject.org>
We now keep track of all errors and total number of request seen. This
is so we can expose those values to the MetricsPort to help Exit
operators monitor the DNS requests and failures.
Related to #40367.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This emits two events (read and write) of the total number that the
global connection limit was reached.
Related to #40367
Signed-off-by: David Goulet <dgoulet@torproject.org>
With this commit, a relay will emit metrics that give the total number
of sockets and total number of opened sockets.
Related to #40367
Signed-off-by: David Goulet <dgoulet@torproject.org>
With this commit, a relay now emits metrics event on the MetricsPort
related to how many onionskins were handled (processed or dropped) for
each handshake type.
Related to #40367
Signed-off-by: David Goulet <dgoulet@torproject.org>
With this commit, a relay now emits metrics event on the MetricsPort
related to the OOM invocation for:
- DNS cache
- GeoIP database
- Cell queues
- HSDir caches
Everytime the OOM is invoked, the number of bytes is added to the
metrics counter for that specific type of invocation.
Related to #40367
Signed-off-by: David Goulet <dgoulet@torproject.org>
The basic functions for the relay subsystem to expose metrics onto the
MetricsPort.
Part of #40367
Signed-off-by: David Goulet <dgoulet@torproject.org>
It is a common function that a lot of subsystem can use which is to
format a label so move it out of the HS subsystem into the more generic
metrics library.
Signed-off-by: David Goulet <dgoulet@torproject.org>
An entry can have multiple labels but only print once the comments at
the first one. This follows the Promtheus best practices.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This change permits the newfstatat() system call, and fixes issues
40382 (and 40381).
This isn't a free change. From the commit:
// Libc 2.33 uses this syscall to implement both fstat() and stat().
//
// The trouble is that to implement fstat(fd, &st), it calls:
// newfstatat(fs, "", &st, AT_EMPTY_PATH)
// We can't detect this usage in particular, because "" is a pointer
// we don't control. And we can't just look for AT_EMPTY_PATH, since
// AT_EMPTY_PATH only has effect when the path string is empty.
//
// So our only solution seems to be allowing all fstatat calls, which
// means that an attacker can stat() anything on the filesystem. That's
// not a great solution, but I can't find a better one.
As of GCC 11.1.1, the compiler warns us about code like this:
if (a)
b;
c;
and that's a good thing: we wouldn't want to "goto fail". But we
had an instance if this in circuituse.c, which was making our
compilation sad.
Fixes bug 40380; bugfix on 0.3.0.1-alpha.
Turns out that passing client authorization keys to ADD_ONION for v3 was
not working because we were not setting the "is_client_auth_enabled"
flag to true once the clients were configured. This lead to the
descriptor being encoded without the clients.
This patch removes that flag and instead adds an inline function that
can be used to check if a given service has client authorization
enabled.
This will be much less error prone of needing to keep in sync the client
list and a flag instead.
Fixes#40378
Signed-off-by: David Goulet <dgoulet@torproject.org>
This function has been a no-op since Libevent 2.0.4-alpha, when
libevent got an arc4random() implementation. Libevent has finally
removed it, which will break our compilation unless we stop calling
it. (This is currently breaking compilation in OSS-fuzz.)
Closes#40371.
This is related to ticket #40360 which found this problem when a Bridge entry
with a transport name (let say obfs4) is set without a fingerprint:
Bridge obfs4 <IP>:<PORT> cert=<...> iat-mode=0
(Notice, no fingerprint between PORT and "cert=")
Problem: commit 09c6d03246 added a check in
get_sampled_guard_for_bridge() that would return NULL if the selected bridge
did not have a valid transport name (that is the Bridge transport name that
corresponds to a ClientTransportPlugin).
Unfortuantely, this function is also used when selecting our eligible guards
which is done *before* the transport list is populated and so the added check
for the bridge<->transport name is querying an empty list of transports
resulting in always returning NULL.
For completion, the logic is: Pick eligible guards (use bridge(s) if need be)
then for those, initiate a connection to the pluggable transport proxy and
then populate the transport list once we've connected.
Back to get_sampled_guard_for_bridge(). As said earlier, it is used when
selecting our eligible guards in a way that prevents us from selecting
duplicates. In other words, if that function returns non-NULL, the selection
continues considering the bridge was sampled before. But if it returns NULL,
the relay is added to the eligible list.
This bug made it that our eligible guard list was populated with the *same*
bridge 3 times like so (remember no fingerprint):
[info] entry_guards_update_primary(): Primary entry guards have changed. New primary guard list is:
[info] entry_guards_update_primary(): 1/3: [bridge] ($0000000000000000000000000000000000000000)
[info] entry_guards_update_primary(): 2/3: [bridge] ($0000000000000000000000000000000000000000)
[info] entry_guards_update_primary(): 3/3: [bridge] ($0000000000000000000000000000000000000000)
When tor starts, it will find the bridge fingerprint by connecting to it and
will then update the primary guard list by calling
entry_guard_learned_bridge_identity() which then goes and update only 1 single
entry resulting in this list:
[debug] sampled_guards_update_consensus_presence(): Sampled guard [bridge] ($<FINGERPRINT>) is still listed.
[debug] sampled_guards_update_consensus_presence(): Sampled guard [bridge] ($0000000000000000000000000000000000000000) is still listed.
[debug] sampled_guards_update_consensus_presence(): Sampled guard [bridge] ($0000000000000000000000000000000000000000) is still listed.
And here lies the problem, now tor is stuck attempting to wait for a valid
descriptor for at least 2 guards where the second one is a bunch of zeroes and
thus tor will never fully bootstraps:
[info] I learned some more directory information, but not enough to build a
circuit: We're missing descriptors for 1/2 of our primary entry guards
(total microdescriptors: 6671/6703). That's ok. We will try to fetch missing
descriptors soon.
Now, why passing the fingerprint then works? This is because the list of
guards contains 3 times the same bridge but they all have a fingerprint and so
the descriptor can be found and tor can bootstraps.
The solution here is to entirely remove the transport name check in
get_sampled_guard_for_bridge() since the transport_list is empty at that
point. That way, the eligible guard list only gets 1 entry, the bridge, and
can then go on to bootstrap properly.
It is OK to do so since when launching a bridge descriptor fetch, we validate
that the bridge transport name is OK and thus avoid connecting to a bridge
without a ClientTransportPlugin. If we wanted to keep the check in place, we
would need to populate the transport_list much earlier and this would require
a much bigger refactoring.
Fixes#40360
Signed-off-by: David Goulet <dgoulet@torproject.org>
