Secured in-tunnel messages and access control

A non-transitory computer-readable medium containing instructions which, when executed, cause a computing device to perform operations comprising:

• establishing a tunneling connection between a server and an endpoint;
• receiving a packet from the server over the tunneling connection, wherein an Internet Protocol (IP) address field of the packet is set to a particular value indicating that the packet is to be inspected by the endpoint;
• determining whether to inspect the packet based on whether the IP address field of the packet is set to the particular value;
• and
• determining, based on the IP address field of the packet, that the packet comprises a tunneling control message, wherein the tunneling control message indicates a tunneling event.

A computer-implemented system, comprising:

• one or more computers;
• and
• one or more computer memory devices interoperably coupled with the one or more computers and having tangible, non-transitory, machine-readable media storing one or more instructions that, when executed by the one or more computers, perform one or more operations comprising:
• establishing a tunneling connection between a server and an endpoint;
• receiving a packet from the server over the tunneling connection, wherein an Internet Protocol (IP) address field of the packet is set to a particular value indicating that the packet is to be inspected by the endpoint;
• determining, whether to inspect the packet based on whether the IP address field of the packet is set to the particular value;
• and
• determining, based on the IP address field of the packet, that the packet comprises a tunneling control message, wherein the tunneling control message indicates a tunneling event.

A computer-implemented method, comprising:

• establishing a tunneling connection between a server and an endpoint;
• receiving a request from the endpoint over the tunneling connection between the server and the endpoint;
• in response to receiving the request, determining a status of the request;
• and
• sending a packet to the endpoint over the tunneling connection, wherein the packet comprises a tunneling control message indicating the status of the request, and an Internet Protocol (IP) address field of the packet is set to a particular value indicating that the packet is to be inspected by the endpoint.