1 files changed, 46 insertions, 0 deletions
diff --git a/bro-script/pasad-simple.bro b/bro-script/pasad-simple.bro
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+## Simple implementation that outputs the raw request and response data 
+## to a log file.
+## Currently, this only handles the read_holding_registers event.  Other
+## events can be handled similarily.  This implementation assumes that
+## requests and responses are exchanged within the same connection.  I am not
+## sure whether this really holds.
+
+module Pasad;
+
+export {
+	redef enum Log::ID += { LOG };
+
+	type Info: record {
+		ts_request:	time	&log;
+		ts_response:	time	&log &optional;
+		rtype: 		string	&log;
+		tid_request:	count	&log;
+		tid_response:	count	&log &optional;
+		start_adress:	count	&log;
+		quantity:	count	&log;
+		registers:	ModbusRegisters &log &optional;
+	};
+}
+
+redef record connection += {
+	pasad: Info &optional;
+};
+
+event bro_init() &priority=5
+	{
+	Log::create_stream(Pasad::LOG, [$columns=Info, $path="pasad"]);
+	}
+
+event modbus_read_holding_registers_request(c: connection, headers: ModbusHeaders, start_adress: count, quantity: count)
+	{
+	local rec: Info = [$ts_request=network_time(), $rtype="holding", $tid_request=headers$tid, $start_adress=start_adress, $quantity=quantity];
+	c$pasad = rec;
+	}
+
+event modbus_read_holding_registers_response(c: connection, headers: ModbusHeaders, registers: ModbusRegisters)
+	{
+		c$pasad$tid_response = headers$tid;
+		c$pasad$ts_response = network_time();
+		c$pasad$registers = registers;
+		Log::write(Pasad::LOG, c$pasad);
+	}