This repo contains two applications that detect the presence of a compression link in a network. The first application operates using a client/server relationship, while the second application is standalone.
The client and server establish a TCP connection in order for the client to share a config file with the server. After parsing the config file, the client sends two UDP packet trains to the server. The first packet train consists of low entropy data and the second packet train consists of high entropy data. The server records the time difference between the first and last packet in each train. It then calculates the time difference between the low entropy train and the high entropy train. The client then resestablishes a TCP connection with the server, and the server reports back to the client whether or not compression was detected. If the difference in arrival time between packet trains was greater than 100 milliseconds, the client will report "Compression Detected". If the difference was less than 100 milliseconds, the client will report "No compression detected".
This application has two main files, server.c and client.c. They are meant to be run in two different terminals or virtual machines.
- Fill out the config.json file with the values you would like to use (some fields are not used by this application)
- In the first terminal, compile the server.c program
gcc -o server server.c config.c cJSON.c
- Start the server application
./server <port number>
- In the second VM, compile the client.c program
gcc -o client client.c config.c cJSON.c
- Start the client application
./client <path to config file>
The application will take some time to run, depending on how long you set the inter-measurement time. Once it completes, you can observe the compression message in the terminal the client is running on.
This application uses raw sockets to detect network compression links. The application parses a config file, then sends two sets of packets. The first set is a SYN packet, followed by a UDP packet train containing low entropy data, followed by a second SYN packet. This process is repeated with high entropy data in the UDP packet. Each SYN packet is sent to an uncommon port where no application is expected to be listening. As a result, RST packets will be sent in response to the SYN packets, because the ports are unreachable. The application listens for RST packets, and calculates the time difference between the first and second RST packet received for each packet train. It then calculates the difference between each packet train. If the difference is greater than 100 milliseconds, the application prints "Compression detected". If it is less than 100 milliseconds, it prints "No compression detected".
This application uses raw sockets, so it requires sudo privledges to run
- Fill out the config.json file with the values you would like to use (some fields are not used by this application)
- Compile the comp_detect.c program
gcc -o comp_detect comp_detect.c config.c cJSON.c
- Start the application
sudo ./comp_detect <path to config file>
The application will take some time to run, depending on how long you set the inter-measurement time. Once it completes, you can observe the compression message in the terminal.