org.eclipse.scada.protocol.ngp.common.mc.handshake

Interface Handshake

All Known Implementing Classes:

AbstractHandshake, MessageProtocolHandshake, SslFeatureHandshake, StartSessionHandshake, StreamCompressionHandshake, TimeoutHandshake

public interface Handshake

A handshake module which will take part on the message channel setup procedure

Author:

Jens Reimann

Method Summary

Modifier and Type	Method and Description
void	apply(HandshakeContext context, Map<String,String> acceptedProperties) Activate the results from the previous handshake run.
void	handshake(HandshakeContext context, Map<String,String> helloProperties, Map<String,String> acceptedProperties) Called by the server and actually performing the handshake based on the helloProperties from the client
void	postApply(HandshakeContext context, Map<String,String> acceptedProperties) A second apply run performed directly after the run to apply(HandshakeContext, Map)
void	request(HandshakeContext context, Map<String,String> helloProperties) Called by the client, putting together all properties for the HelloMessage
void	sessionStarted(HandshakeContext context, Map<String,String> acceptedProperties) Called on the server and client when the session got started.

Method Detail

request

void request(HandshakeContext context,
             Map<String,String> helloProperties)

Called by the client, putting together all properties for the HelloMessage

Parameters:

context - the handshake context

helloProperties - the properties to fill

handshake

void handshake(HandshakeContext context,
               Map<String,String> helloProperties,
               Map<String,String> acceptedProperties)
        throws Exception

Called by the server and actually performing the handshake based on the helloProperties from the client

The server needs to evaluate what the client requested and puts the result into the acceptedProperties. No action will be done right now. The result in the acceptedProperties will also be sent to the client.

Parameters:

context - the handshake context

helloProperties - the properties from the client

acceptedProperties - the properties to fill with the result of the handshake

Throws:

Exception - if anything goes wrong

apply

void apply(HandshakeContext context,
           Map<String,String> acceptedProperties)
    throws Exception

Activate the results from the previous handshake run. This is called on the server directly and on the client when the AcceptMessage was received.

In this phase all handshake modules should apply the changes needed. They may also change the sessions filter chain to change the way it communicates.

This method will be called before the ACCEPT/START packet is sent. This means that on the server side filters that change the encoding must be deactivated for the first packet. On the client side the first packet must already be encoded.

Parameters:

context - the handshake context

acceptedProperties - the accepted properties from the servers handshake run

Throws:

Exception - if anything goes wrong

postApply

void postApply(HandshakeContext context,
               Map<String,String> acceptedProperties)
        throws Exception

A second apply run performed directly after the run to apply(HandshakeContext, Map)

This second apply run has the possibility to perform stuff which needs to be done after all changes to the filter change have been performed. So messages sent in this phase will already be encoded correctly.

Parameters:

context - the handshake context

acceptedProperties - the accepted properties from the servers handshake run

Throws:

Exception - if anything goes wrong

sessionStarted

void sessionStarted(HandshakeContext context,
                    Map<String,String> acceptedProperties)
             throws Exception

Called on the server and client when the session got started.

For the server this may either be directly after the handshake run or later when the StartMessage has been received. This depends on the fact weather the client supports the session start command.

For the client this is after the session has been accepted

Parameters:

context - the handshake context

acceptedProperties - the accepted properties from the servers handshake run

Throws:

Exception - if anything goes wrong