zeek/policy/terminate-connection.bro

65 lines
1.7 KiB
Text

# $Id$
@load site
@load notice
# Ugly: we need the following from conn.bro, but we can't soundly load
# it because it in turn loads us.
global full_id_string: function(c: connection): string;
module TerminateConnection;
export {
redef enum Notice += {
TerminatingConnection, # connection will be terminated
TerminatingConnectionIgnored, # connection terminated disabled
};
# Whether we're allowed (and/or are capable) to terminate connections
# using "rst".
const activate_terminate_connection = F &redef;
# Terminate the given connection.
global terminate_connection: function(c: connection);
}
function terminate_connection(c: connection)
{
local id = c$id;
if ( activate_terminate_connection )
{
local local_init = is_local_addr(id$orig_h);
local term_cmd = fmt("rst %s -n 32 -d 20 %s %d %d %s %d %d",
local_init ? "-R" : "",
id$orig_h, id$orig_p, get_orig_seq(id),
id$resp_h, id$resp_p, get_resp_seq(id));
if ( reading_live_traffic() )
system(term_cmd);
else
NOTICE([$note=TerminatingConnection, $conn=c,
$msg=term_cmd, $sub="first termination command"]);
term_cmd = fmt("rst %s -r 2 -n 4 -s 512 -d 20 %s %d %d %s %d %d",
local_init ? "-R" : "",
id$orig_h, id$orig_p, get_orig_seq(id),
id$resp_h, id$resp_p, get_resp_seq(id));
if ( reading_live_traffic() )
system(term_cmd);
else
NOTICE([$note=TerminatingConnection, $conn=c,
$msg=term_cmd, $sub="second termination command"]);
NOTICE([$note=TerminatingConnection, $conn=c,
$msg=fmt("terminating %s", full_id_string(c))]);
}
else
NOTICE([$note=TerminatingConnectionIgnored, $conn=c,
$msg=fmt("ignoring request to terminate %s",
full_id_string(c))]);
}