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>
Rationale: this helps for performance only, but we don't actually
have any reason to think that the checks here are
performance-critical. Let's not normalize the use of unsafe {}.
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>
* FIXES#25127: https://bugs.torproject.org/25127
* ADDS a new module to the Rust tor_util crate for small utilities
for working with static strings between languages.
* CHANGES the return type of protover_compute_for_old_tor to point to
immutable data.
* CHANGES the code from the previous commit to use the new static
string utilities.
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>
On slow system, 1 msec between one read and the other was too tight. For
instance, it failed on armel with a 4msec gap:
https://buildd.debian.org/status/package.php?p=tor&suite=experimental
Increase to 10 msec for now to address slow system. It is important that we
keep this OP_LE test in so we make sure the msec/usec/nsec read aren't
desynchronized by huge gaps. We'll adjust again if we ever encounter a system
that goes slower than 10 msec between calls.
Fixes#25113
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>
This tests many cases of the KIST scheduler with the pending list state by
calling entry point in the scheduler while channels are scheduled or not.
Also, it adds a test for the bug #24700.
Signed-off-by: David Goulet <dgoulet@torproject.org>
This patch makes the wording around error cases for selecting an entropy
source in Tor slightly more verbose. We also let the user know when
something goes wrong that we are trying out a fallback method instead.
See: https://bugs.torproject.org/25120
Included crypto_rsa.[ch] into include.am in order to resolve a compiling issue.
Follows #24658.
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
crypto_get_rsa_padding_overhead() and crypto_get_rsa_padding() are
not static inline anymore in order to split the crypto_rsa module
from crypto.[ch].
Also included necessary modules in order to solve dependency issues.
Also made two functions in crypto.c use crypto_pk_asn1_encdoe()
instead of reaching into the crypto_pk_t struct.
This reverts commit 9a06282546.
It appears that I misunderstood how the seccomp2 filter rules
interact. It appears that `SCMP_ACT_ERRNO()` always takes
precedence over `SCMP_ACT_ALLOW()` -- I had thought instead that
earlier rules would override later ones. But this change caused bug
25115 (not in any released Tor).
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>
And fix the unsupported protover example so it uses a Link protover much
higher than 5.
Part of #25070, bugfix on 0.3.3.1-alpha, which introduced the protover crate.
Add two new files (crypto_rsa.c, crypto_rsa.h) as new module of crypto.[ch].
This new module includes all functions and dependencies related to RSA
operations. Those have been removed from crypto.[ch].
All new changes related to RSA operations must be done in these files.
Follows #24658
Signed-off-by: Fernando Fernandez Mancera <ffmancera@riseup.net>
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.
