The changes are mostly quite minor. The main change reasons are:
* analyzers that were confirmed, and later removed now show up in the
conn.log.
* a couple of removed lines in analyzer.log, because non-confirmed
analyzers get removed more quickly.
* in some cases there are additional lines in analyzer.log. These are
cases in which an analyzer gets removed due to a violation and then
re-attached because of a later signature match, which replays the
violating content. In all examples that I have so far, this is caused
by both sides of a connection speaking a differing protocol. There
probably should be a better way to handle this - but it works.
* new column for failed analyzers in conn.log
This introduces ian options, DPD::track_removed_services_in_connection.
It adds failed services to the services column, prefixed with a
"-".
Alternatively, this commit also adds
policy/protocols/conn/failed-services.zeek, which provides the same
information in a new column in conn.log.
This changes service set in the connection record, and thus also the
conn.log service field to being ordered. Speficically, the order of the
entries in the service field will be the same order in which protocols
will be confirmed. This means that it now is possible to see which
protocols were layered over each other in which order by looking at the
respective conn.log entry.
This commit revamps the handling of analyzer violations that happen
before an analyzer confirms the protocol.
The current state is that an analyzer is disabled after 5 violations, if
it has not been confirmed. If it has been confirmed, it is disabled
after a single violation.
The reason for this is a historic mistake. In Zeek up to versions 1.5,
analyzers were unconditianally removed when they raised the first
protocol violation.
When this script was ported to the new layout for Zeek 2.0 in
b4b990cfb5, a logic error was introduced
that caused analyzers to no longer be disabled if they were not
confirmed.
This was the state for ~8 years, till the DPD::max_violations options
was added, which instates the current approach of disabling unconfirmed
analyzers after 5 violations. Sadly, there is not much discussion about
this change - from my hazy memory, I think this was discovered during
performance tests and the new behavior was added without checking into
the history of previous changes.
This commit reinstates the originally intended behavior of DPD. When an
analyzer that has not been confirmed raises a protocol violation, it is
immediately removed from the connection. This also makes a lot of sense
- this allows the analyzer to be in a "tasting" phase at the beginning
of the connection, and to error out quickly once it realizes that it was
attached to a connection not containing the desired protocol.
This change also removes the DPD::max_violations option, as it no longer
serves any purpose after this change. (In practice, the option remains
with an &deprecated warning, but it is no longer used for anything).
There are relatively minimal test-baseline changes due to this; they are
mostly triggered by the removal of the data structure and by less
analyzer errors being thrown, as unconfirmed analyzers are disabled
after the first error.
This switches the DPD logic to always log analyzers that raised a
protocol confirmation.
The logic is that, once a protocol has been confirmed - and thus there
probably is log output - it does not make sense to later remove it from
the log. It does make sense to somehow flag it as failed - but that
seems like a secondary step.
I noticed that the IRC analyzer always confirms connections, pretty much
without regard what happened in it. This commit changes the logic of the
IRC analyzer to check for valid commands before confirming.
* origin/topic/johanna/gh-4061:
Update BiF-tracking, add is_event_handled
Address review comments and small updates for DNS warnings
Raise warnings when for DNS events that are not raised due to dns_skip_all_addl
If a plugin provides a write hook, the invocation for HookLogWrite() would
redo looking up the writer's name from the enum value and instantiating
a new std::string instance for every write. Avoid doing this.
There's two instances of WriterBackend::WriterInfo for a given
writer. One in Manager::WriterInfo that's accessible via
stream.writers and a copy within WriterFrontend.
Commit 78999d147d switched to use the
address of the frontend's info instance for HookLogWrite() invocations,
breaking users using the address for identification purposes.
224.0.0.0/24 (and 6to4 conversion 2002:e000::/40) from RFC5771 "Multicast Local Network Control Block" defined as non-routable.
239.0.0.0/8 (and 6to4 conversion 2002:ef00::/24) from RFC2365 "Administratively Scoped IP Multicast"
fec0::/10 from RFC3879 "Deprecated Site Local Addresses"
(cherry picked from commit 821ab2dbed)
