Merge remote-tracking branch 'origin/topic/dina/modbus' into topic/robin/modbus-merge

* origin/topic/dina/modbus:
  put some make-up on Modbus analyser
  Modbus analyser, added support: FC=20,21
  Modbus analyzer,added support: FC=1,2,15,24
  Modbus analyzer, current support: FC=3,4,5,6,7,16,22,23

I cleaned up the code a bit, mainly layout style.

I did not include the *.bro scripts for now, but a test script
../testing/btest/scripts/base/protocols/modbus/events.bro that prints
out the value for each event.

Merged the Modbus traces from the ics repository into a single trace
as input for the test. They currently trigger 20 of the 34 events.

Addresses #870.

src/Modbus.h

@@ -0,0 +1,66 @@
+
+#ifndef MODBUS_H
+#define MODBUS_H
+
+#include "TCP.h"
+
+#include "modbus_pac.h"
+
+class ModbusTCP_Analyzer : public TCP_ApplicationAnalyzer {
+public:
+	ModbusTCP_Analyzer(Connection* conn);
+	virtual ~ModbusTCP_Analyzer();
+
+	virtual void Done();
+	virtual void DeliverStream(int len, const u_char* data, bool orig);
+
+	virtual void Undelivered(int seq, int len, bool orig);
+	virtual void EndpointEOF(TCP_Reassembler* endp);
+
+	static Analyzer* InstantiateAnalyzer(Connection* conn)
+		{ return new ModbusTCP_Analyzer(conn); }
+
+	// Put event names in this function
+	static bool Available()
+		{
+		return modbus_read_coils_request
+			|| modbus_read_coils_response
+			|| modbus_read_input_discretes_request
+			|| modbus_read_input_discretes_response
+			|| modbus_read_multi_request
+			|| modbus_read_multi_response
+			|| modbus_read_input_request
+			|| modbus_read_input_response
+			|| modbus_write_single_request
+			|| modbus_write_single_response
+			|| modbus_write_coil_request
+			|| modbus_write_coil_response
+			|| modbus_force_coils_request
+			|| modbus_force_coils_response
+			|| modbus_read_reference_request
+			|| modbus_read_reference_response
+			|| modbus_read_single_reference_request
+			|| modbus_read_single_reference_response
+			|| modbus_write_reference_request
+			|| modbus_write_reference_response
+			|| modbus_write_single_reference
+			|| modbus_write_multi_request
+			|| modbus_write_multi_response
+			|| modbus_mask_write_request
+			|| modbus_mask_write_response
+			|| modbus_read_write_request
+			|| modbus_read_write_response
+			|| modbus_read_FIFO_request
+			|| modbus_read_FIFO_response
+			|| modbus_read_except_request
+			|| modbus_read_except_response
+			|| modbus_exception
+			|| modbus_request
+			|| modbus_response;
+		}
+
+protected:
+	binpac::ModbusTCP::ModbusTCP_Conn* interp;
+};
+
+#endif