Do not just track the analyzer instance in the stack, but also the
data span it is given. This allows to extract more information on-demand
during event processing.
TrackAnalyzer() is technically a public API, but no one should use it
outside of the Analyzer's Forward methods itself.
When a specific component is requested through its tag or name, one
can now have the component manager transparently return a different
one that has been registered to replace the original one. We limit
this to disabled components to avoid unnecessary confusion. That also
means that remappings are currently only supported for analyzers
(because other types of components cannot be disabled for now, per the
previous change).
While it seems interesting functionality, this hasn't been documented,
maintained or knowingly leveraged for many years.
There are various other approaches today, too:
* We track the number of event handler invocations regardless of
profiling. It's possible to approximate a load_sample event by
comparing the result of two get_event_stats() calls. Or, visualize
the corresponding counters in a Prometheus setup to get an idea of
event/s broken down by event names.
* HookCallFunction() allows to intercept script execution, including
measuring the time execution takes.
* The global call_stack and g_frame_stack can be used from plugins
(and even external processes) to walk the Zeek script stack at certain
points to implement a sampling profiler.
* USDT probes or more plugin hooks will likely be preferred over Zeek
builtin functionality in the future.
Relates to #3458
This largely copies over Spicy's `.clang-format` configuration file. The
one place where we deviate is header include order since Zeek depends on
headers being included in a certain order.
Before, that API was part of the analyzers themselves, which meant we
couldn't disable a packet analyzer before it had been instantiated.
That's different from protocol/file analyzers, where we disable them
through the corresponding component. The lack of the component-side
API prevented Spicy from replacing packet analyzers at startup.
The reason we had put this into analyzer originally was performance so
that we don't need a component lookup for every packet. This change
keeps that optimization by caching the on/off state in the analyzer
itself as well, but now with the component being the one controlling
it.
This adds machinery to the packet_analysis manager for disabling
and enabling packet analyzers and implements two low-level bifs
to use it.
Extend Analyzer::enable_analyzer() and Analyzer::disable_analyzer()
to transparently work with packet analyzers, too. This also allows
to add packet analyzers to Analyzer::disabled_analyzers.
This allows us to create an EnumType that groups all of the analyzer
tag values into a single type, while still having the existing types
that split them up. We can then use this for certain events that benefit
from taking all of the tag types at once.
- Remove tag types for each component type (analyzer, etc)
- Add deprecated versions of the old types
- Remove unnecessary tag element from templates for TaggedComponent and ComponentManager
- Enable TaggedComponent to pass an EnumType when initializing Tag objects
- Update some tests that are affected by the tag enum values changing order
This commit also changes the PcapDumper to automatically flush after
every called to Dump(). This is because pcap_dump has an internal buffer
of some sort that only writes to the file after a set amount of bytes.
When using the new option on a low-traffic network, it might be a while
before you see any packets written since it has to overcome that buffer
limit first.
This also includes:
- Deprecating the NetSessions name.
- Renaming the zeek::sessions global to zeek::session_mgr and deprecating the old name.
- Renaming Sessions.{h,cc} to SessionManager.{h,cc}.
This is still WIP and includes the following changes:
* Dispatchers are now part of analyzers (moving dispatching logic from
the manager to the analyzers)
* All available analyzers are instantiated on start up
* Removal of configuration class
