Restrict connections to the Restlet tunnel server from SDC agents

[ssrini]

Assume an agent was configured to connect to a tunnel server and The connection parameters were provided. It is required that later we do not want to allow the SDC agent to connect to the tunnel server any more. Reasons could be many, for eg. trial period of that user expired or maybe the user has not paid the current fee etc.

Require a mechanism to restrict connections to the Restlet SDC Tunnel either based on IP or based on domain.

[jlouvel]

Currently you have to rely on your network firewall. We definitely need to fill this gap.

Contributions would be welcome on this front.

[jlouvel]

Related issue:
#404

[ssrini]

The related issue is for accessing resources via the agent and filtering them .. so outbound. This issue is inbound ie. which tunnel agents are allowed to connect to the server.

[jlouvel]

Closing as we removed SDC extension previously