This patch adds the ability to decap Geneve packets to process the inner
payload. The structure of the analyzer borrows heavily from the VXLAN
analyzer.
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 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.
* 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"
* Better parsing/error-checking of VXLAN and encapsulated packet headers
* Add/implement the "vxlan_packet" event
* Add "Tunnel::vxlan_ports" option to tune the set of VXLAN ports to
analyze/decapsulate
* Add "Tunnel::validate_vxlan_checksums" option to allow for tuning of how
checksums associated with the outer UDP header of a possible VXLAN
tunnel are handled
Fixes GH-250
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
The text from these README files appears on the "Bro Script Packages"
page after building the documentation. The text for these was mostly just
copied from the existing docs.
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.
Added a generic gtpv1_message event generated for any GTP message type.
Added specific events for the create/update/delete PDP context
request/response messages.
Addresses #934.
This currently supports automatic decapsulation of GTP-U packets on
UDP port 2152.
The GTPv1 headers for such tunnels can be inspected by handling the
"gtpv1_g_pdu_packet" event, which has a parameter of type "gtpv1_hdr".
Analyzer and test cases are derived from submissions by Carsten Langer.
Addresses #690.
- Make the uid field optional since it's conceptually incorrect
for proxies being treated as tunnels to have it.
- Reordered two fields in the log.
- Reduced the default tunnel expiration interface to something more
reasonable (1 hour).
- 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.
Merge remote-tracking branch 'origin/topic/tunnels' into topic/robin/tunnels-merge
* origin/topic/tunnels: (41 commits)
Extend weird names that occur in core packet processing during decapsulation.
Add Teredo analysis option to reduce false positive decapsulation.
Just some cleanup/documentation of new tunnel-handling code.
Memory leak fixes
Add a config.h definition for IPPROTO_IPV4.
Add AYIYA tunnel decapsulation unit test.
Add Teredo-specific events.
Refactor some of the NetSessions routines that recurse on IP packets.
Add independent options to toggle the different decapsulation methods
Add more sanity checks before recursing on encapsulated IP packets.
Suppress Teredo weirds unless decapsulation was successful once before.
Tunnel support performance optimization.
Add Teredo tunnel decapsulation.
Fix for IP tunnel UID persistence.
Fix AYIYA analyzer tag.
Add summary documentation to tunnels/main.bro.
Make tunnels always identifiable by UID, tunnel.log now gets populated.
Some improvements to the AYIYA analyzer.
Remove Tunnel::decapsulate_ip option.
Remove invalid IP-in-IP encapsulated protocol value.
...
Also fix header truncation check for IPv6 No Next header and add an
"ipv6_no_next" weird for such packets that aren't tunneled over Teredo
(which it calls "bubbles" and are used to create mappings in NATs).
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.
- AYIYA works.
- AYIYA analyzed connections are still labelled wrong in conn.log (logged as syslog)
- Some clean up for left over code.
- Small refactoring to pass packets back from analyzers to core.
- $uid is now optional in conn logs since ip-in-ip tunnel parent's
won't have an actual connection.
