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.
The RSTOS0 `conn_state` label is documented as "Originator sent a SYN
followed by a RST, never saw SYN-ACK from responder", but was previously
applied to cases where no originator SYN exists, like a single RST-only
packet.
This adds two new functions: `Conn::register_removal_hook()` and
`Conn::unregister_removal_hook()` for registering a hook function to be
called back during `connection_state_remove`. The benefit of using hook
callback approach is better scalability: the overhead of unrelated
protocols having to dispatch no-op `connection_state_remove` handlers is
avoided.
And switch Zeek's base scripts over to using it in place of
"connection_state_remove". The difference between the two is
that "connection_state_remove" is raised for all events while
"successful_connection_remove" excludes TCP connections that were never
established (just SYN packets). There can be performance benefits
to this change for some use-cases.
There's also a new event called ``connection_successful`` and a new
``connection`` record field named "successful" to help indicate this new
property of connections.
Now, in addition to setting thresholds for bytes and packet, one can set
a threshold for connection duration. Note that the threshold event is
only raised once the next packet in the connection is seen.
This also fixes a small pre-existing bug, in which a bunch of warnings
were raised if someone just used the lower-level functions without going
through the higher-level scripting API.
* All "Broxygen" usages have been replaced in
code, documentation, filenames, etc.
* Sphinx roles/directives like ":bro:see" are now ":zeek:see"
* The "--broxygen" command-line option is now "--zeexygen"
* origin/topic/vern/content-gap-history:
Refined state machine update placement to (1) properly deal with gaps capped by clean FIN handshakes, and (1) fix failure to detect split routing.
added 'g' $history character for content gaps
This makes conn.logs a bit prettier (and smaller) because all lines that
do not use a tunnel will now have a "-" instead of the "(empty)" for
tunnel_parents.
Noticed these gave warnings due to missing namespace, but rather than
fix I'm just removing because they reference names in the same
module/file that will appear inches away from each other in the final
output.
* origin/topic/johanna/conn-threshold:
Wrap threshold stuff up - fix two small bugs and update baselines.
update GridFTP analyzer to use connection thresholding instead of polling
Add high level api for thresholding that holds lists of thresholds and raises an event for each threshold exactly once.
Allow setting packet and byte thresholds for connections.
BIT-1377 #merged
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.
* origin/topic/jsiwek/gridftp:
Add memory leak unit test for GridFTP.
Enable GridFTP detection by default. Track/log SSL client certs.
Add analyzer for GSI mechanism of GSSAPI FTP AUTH method.
Add an example of a GridFTP data channel detection script.
It relies on the heuristics of GridFTP data channels commonly default to
SSL mutual authentication with a NULL bulk cipher and that they usually
transfer large datasets (default threshold of script is 1 GB). The
script also defaults to skip_further_processing() after detection to try
to save cycles analyzing the large, benign connection.
Also added a script in base/protocols/conn/polling that generalizes the
process of polling a connection for interesting features. The GridFTP
data channel detection script depends on it to monitor bytes
transferred.
- Clarify "tunnel_changed" event documentation.
- Make expiration of "Tunnel::active" elements configuration via
"Tunnel::expiration_interval".
- Remove redundant registration of a connection's tunnels in
tunnel/main.bro's "tunnel_changed" handler.
- Rename "parents" field of "Conn::Info" to "tunnel_parents"
to give more context.
conn.log now sets a field indicating all the parent tunnel UIDs over
which a connection operated and cross reference the UIDs found in
the tunnel.log.
Also some renaming of tunnel related types at the scripting layer.
