Task

• Create simple TCP based client-server application.
• Create a proxy application (that is in the middle).
• Application logic:
  • Client sends data to Proxy.
  • Option1: Proxy just forwards it to the server.
  • Option2: Proxy does modifications in payload and resend them to server.

For Option2: Server must figure out that data has been changed in the middle (calculating packet checksum).

Sequence diagram of implementation

Run application

1. Build with cmake

cmake CMakeLists.txt

2. Build application with make

make

3. Run (sudo usage is mandatory since raw sockets require root privileges)

sudo ./packets_checker