zeek/scripts/base/protocols/dnp3/main.zeek
Jon Siwek 05cf511f18 GH-1119: add base/protcols/conn/removal-hooks.zeek
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.
2020-09-11 12:12:10 -07:00

83 lines
2.1 KiB
Text

##! A very basic DNP3 analysis script that just logs requests and replies.
@load ./consts
@load base/protocols/conn/removal-hooks
module DNP3;
export {
redef enum Log::ID += { LOG };
type Info: record {
## Time of the request.
ts: time &log;
## Unique identifier for the connection.
uid: string &log;
## Identifier for the connection.
id: conn_id &log;
## The name of the function message in the request.
fc_request: string &log &optional;
## The name of the function message in the reply.
fc_reply: string &log &optional;
## The response's "internal indication number".
iin: count &log &optional;
};
## Event that can be handled to access the DNP3 record as it is sent on
## to the logging framework.
global log_dnp3: event(rec: Info);
## DNP3 finalization hook. Remaining DNP3 info may get logged when it's called.
global finalize_dnp3: Conn::RemovalHook;
}
redef record connection += {
dnp3: Info &optional;
};
const ports = { 20000/tcp , 20000/udp };
redef likely_server_ports += { ports };
event zeek_init() &priority=5
{
Log::create_stream(DNP3::LOG, [$columns=Info, $ev=log_dnp3, $path="dnp3"]);
Analyzer::register_for_ports(Analyzer::ANALYZER_DNP3_TCP, ports);
}
event dnp3_application_request_header(c: connection, is_orig: bool, application_control: count, fc: count)
{
if ( ! c?$dnp3 )
{
c$dnp3 = [$ts=network_time(), $uid=c$uid, $id=c$id];
Conn::register_removal_hook(c, finalize_dnp3);
}
c$dnp3$ts = network_time();
c$dnp3$fc_request = function_codes[fc];
}
event dnp3_application_response_header(c: connection, is_orig: bool, application_control: count, fc: count, iin: count)
{
if ( ! c?$dnp3 )
{
c$dnp3 = [$ts=network_time(), $uid=c$uid, $id=c$id];
Conn::register_removal_hook(c, finalize_dnp3);
}
c$dnp3$ts = network_time();
c$dnp3$fc_reply = function_codes[fc];
c$dnp3$iin = iin;
Log::write(LOG, c$dnp3);
delete c$dnp3;
}
hook finalize_dnp3(c: connection)
{
if ( ! c?$dnp3 )
return;
Log::write(LOG, c$dnp3);
delete c$dnp3;
}