This adds a "policy" hook into the logging framework's streams and
filters to replace the existing log filter predicates. The hook
signature is as follows:
hook(rec: any, id: Log::ID, filter: Log::Filter);
The logging manager invokes hooks on each log record. Hooks can veto
log records via a break, and modify them if necessary. Log filters
inherit the stream-level hook, but can override or remove the hook as
needed.
The distribution's existing log streams now come with pre-defined
hooks that users can add handlers to. Their name is standardized as
"log_policy" by convention, with additional suffixes when a module
provides multiple streams. The following adds a handler to the Conn
module's default log policy hook:
hook Conn::log_policy(rec: Conn::Info, id: Log::ID, filter: Log::Filter)
{
if ( some_veto_reason(rec) )
break;
}
By default, this handler will get invoked for any log filter
associated with the Conn::LOG stream.
The existing predicates are deprecated for removal in 4.1 but continue
to work.
This allows the path for the default filter to be specified explicitly
when creating a stream and reduces the need to rely on the default path
function to magically supply the path.
The default path function is now only used if, when a filter is added to
a stream, it has neither a path nor a path function already.
Adapted the existing Log::create_stream calls to explicitly specify a
path value.
Addresses BIT-1324
This is a larger internal change that moves the analyzer
infrastructure to a more flexible model where the available analyzers
don't need to be hardcoded at compile time anymore. While currently
they actually still are, this will in the future enable external
analyzer plugins. For now, it does already add the capability to
dynamically enable/disable analyzers from script-land, replacing the
old Analyzer::Available() methods.
There are three major parts going into this:
- A new plugin infrastructure in src/plugin. This is independent
of analyzers and will eventually support plugins for other parts
of Bro as well (think: readers and writers). The goal is that
plugins can be alternatively compiled in statically or loadead
dynamically at runtime from a shared library. While the latter
isn't there yet, there'll be almost no code change for a plugin
to make it dynamic later (hopefully :)
- New analyzer infrastructure in src/analyzer. I've moved a number
of analyzer-related classes here, including Analyzer and DPM;
the latter now renamed to Analyzer::Manager. More will move here
later. Currently, there's only one plugin here, which provides
*all* existing analyzers. We can modularize this further in the
future (or not).
- A new script interface in base/framework/analyzer. I think that
this will eventually replace the dpm framework, but for now
that's still there as well, though some parts have moved over.
I've also remove the dpd_config table; ports are now configured via
the analyzer framework. For exmaple, for SSH:
const ports = { 22/tcp } &redef;
event bro_init() &priority=5
{
...
Analyzer::register_for_ports(Analyzer::ANALYZER_SSH, ports);
}
As you can see, the old ANALYZER_SSH constants have more into an enum
in the Analyzer namespace.
This is all hardly tested right now, and not everything works yet.
There's also a lot more cleanup to do (moving more classes around;
removing no longer used functionality; documenting script and C++
interfaces; regression tests). But it seems to generally work with a
small trace at least.
The debug stream "dpm" shows more about the loaded/enabled analyzers.
A new option -N lists loaded plugins and what they provide (including
those compiled in statically; i.e., right now it outputs all the
analyzers).
This is all not cast-in-stone yet, for some things we need to see if
they make sense this way. Feedback welcome.
* remotes/origin/topic/seth/modbus-merge:
Small modbus documentation update and tiny refactoring.
Final touches to modbus analyzer for now.
Major revisions to Modbus analyzer support (not quite done yet).
put some make-up on Modbus analyser
Modbus analyser, added support: FC=20,21
Modbus analyzer,added support: FC=1,2,15,24
Modbus analyzer, current support: FC=3,4,5,6,7,16,22,23
Closes#915.
- There are still some broken events in the modbus analyzer because
I don't have traffic to test with (coil and record related events primarily).
- There are a few example scripts in policy/protocols/modbus
- Renamed many data structures to align with most recent standard.
- Reworked modbus events to make them more canonically "Bro".
- Converted the Modbus analyzer to a simpler style for easier maintenance.
- Modbus coil related events still don't work (I haven't finished the
function for converting the data structures).
- Modbus file record events remain incomplete.
* origin/topic/dina/modbus:
put some make-up on Modbus analyser
Modbus analyser, added support: FC=20,21
Modbus analyzer,added support: FC=1,2,15,24
Modbus analyzer, current support: FC=3,4,5,6,7,16,22,23
I cleaned up the code a bit, mainly layout style.
I did not include the *.bro scripts for now, but a test script
../testing/btest/scripts/base/protocols/modbus/events.bro that prints
out the value for each event.
Merged the Modbus traces from the ics repository into a single trace
as input for the test. They currently trigger 20 of the 34 events.
Addresses #870.
