zeek/scripts/base/frameworks/analyzer/main.bro
Robin Sommer af1809aaa3 First prototype of new analyzer framework.
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.
2013-03-26 11:05:38 -07:00

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module Analyzer;
# Analyzer::Tag is defined in types.bif, and automatically extended by plugins
# as they are loaded.
export {
## XXX.
global enable_analyzer: function(tag: Analyzer::Tag) : bool;
## XXX.
global disable_analyzer: function(tag: Analyzer::Tag) : bool;
## XXX.
global register_for_ports: function(tag: Analyzer::Tag, ports: set[port]) : bool;
## XXX.
global register_for_port: function(tag: Analyzer::Tag, p: port) : bool;
## XXX.
global registered_ports: function(tag: Analyzer::Tag) : set[port];
## Translate an analyzer type to an ASCII string.
##
## atype: The analyzer tag.
##
## Returns: The analyzer *aid* as string.
global name: function(atype: Analyzer::Tag) : string;
## Schedules an analyzer for a future connection from a given IP address and
## port. The function ignores the scheduling request if the connection did
## not occur within the specified time interval.
##
## orig: The IP address originating a connection in the future.
##
## resp: The IP address responding to a connection from *orig*.
##
## resp_p: The destination port at *resp*.
##
## analyzer: The analyzer ID.
##
## tout: The timeout interval after which to ignore the scheduling request.
##
## Returns: True if succesful.
global expect_connection: function(orig: addr, resp: addr, resp_p: port,
analyzer: Analyzer::Tag, tout: interval) : bool;
## Analyzers to disable at startup.
global disabled_analyzers: set[Analyzer::Tag] = {
ANALYZER_INTERCONN,
ANALYZER_STEPPINGSTONE,
ANALYZER_BACKDOOR,
ANALYZER_TCPSTATS,
}
&redef;
}
@load base/analyzer.bif
global ports: table[Analyzer::Tag] of set[port];
event bro_init()
{
for ( a in disabled_analyzers )
disable_analyzer(a);
}
function enable_analyzer(tag: Analyzer::Tag) : bool
{
return __enable_analyzer(tag);
}
function disable_analyzer(tag: Analyzer::Tag) : bool
{
return __disable_analyzer(tag);
}
function register_for_ports(tag: Analyzer::Tag, ports: set[port]) : bool
{
local rc = T;
for ( p in ports )
{
if ( ! register_for_port(tag, p) )
rc = F;
}
return rc;
}
function register_for_port(tag: Analyzer::Tag, p: port) : bool
{
if ( ! __register_for_port(tag, p) )
return F;
if ( tag !in ports )
ports[tag] = set();
add ports[tag][p];
return T;
}
function registered_ports(tag: Analyzer::Tag) : set[port]
{
return tag in ports ? ports[tag] : set();
}
function name(atype: Analyzer::Tag) : string
{
return __name(atype);
}
function expect_connection(orig: addr, resp: addr, resp_p: port,
analyzer: Analyzer::Tag, tout: interval) : bool
{
return __expect_connection(orig, resp, resp_p, analyzer, tout);
}