kfp

Created By Eric Tsang and Ben Soer

kfp is a Kotlin based Forwaridng Proxy / Port Forwarding application that allows users to redirect UDP or TCP traffic to a designated host on a specific IP. The project runs multi-threaded with a GUI allowing realtime responsiveness to changes applied on port forwards. Additionaly the system monitors traffic quanities and the number of connections made through the various ports that are forwarded. Users observing the GUI can watch in real-time the amount of traffic passing through the Port Forwarder at any gvien time.

Setup

Prerequisites:

Before you can run the application you will need to have the latest Java 8 installed. You can download Java 8 here.

Compile The Project:

For the next steps it is assumed that the command java can be called from any location on the terminal.

To setup 8005-fp-portforwarder do the following:

1. Clone the Project / Download the Project
2. cd into the root project directory
3. Call ./gradlew jar (Permissions of the ./gradle script may need to be modified to be executable. 667 should be sufficient)
4. Call java -jar build/libs/kfp.jar
5. The program should begin initializing

Known Compiling Issues:

If you get errors in step 3 about the ./gradlew file not being found. Try executing step 3 with the following command:

bash ./gradlew jar

The problem may be because the gradlew script's shibang looks for bash in the /usr/bin/env folder. On systems such as Fedora 22, bash is located in /usr/bin and thus this script fails to execute

If you get errors in step 3 looking like this:

./gradlew: line 2: $'\r': command not found
./gradlew: line 8: $'\r': command not found
./gradlew: line 11: $'\r': command not found
./gradlew: line 14: $'\r': command not found
./gradlew: line 17: $'\r': command not found
./gradlew: line 18: syntax error near unexpected token `$'{\r''
'/gradlew: line 18: `warn ( ) {

It means the gradlew's file is using an improper line ending characters for your operating system. If you are on a unix/linux system you can fix this by calling dos2unix ./gradlew. This will correct the line endings

Usage

The Port Forwarding Application is quite straight forward. All activities are carried out on the GUI.

Add An Entry

To add a port forwarding entry simply enter in the entry list:

1. the port to listen on, followed by
2. the protocol to be used (either TCP or UDP)
3. the destination host and port that the port forwarder will forward all of its traffic to.
4. wait for the text entries to turn white

Remove An Entry

To remove a forwarding entry simply delete it from the list or make it invalid by changing any of the entry boxes to an invalid one.

Update An Entry

Update an entry by simply changing the values in the entry boxes you would like to change. The port forwarder will update your changes after a second of no activity on the entry and that the new entry is deemed valid.

View Real-Time Statistics

To be able to observe the real-time stats, make a connection to the port forwarder that involves data to pass through the port forwarder. The port forwarder will immediately start displaying stats as the data passes through the port forwarder

Notes. Tips. Tricks.

• If you don't know the IP of the host you can also enter in domain names (eg facebook.com) instead of an IP and the port forwarder will automatically DNS resolve it to its appropriate IP.

• If the text entries do not turn white in Step 4, it means the entered ports, IP or domain entered are invalid for the forwarding entry you are trying to make. The port forwarder will only add records when a valid forwarding entry is added.

• If you are entering a domain name for an IP, the text entries may not turn white because the port forwarder was unable to make a DNS lookup on the domain. This could be caused by no internet connection, a blocked DNS lookup, or your local DNS does not yet contain the A record at the time of the query.

• If a TCP entry is removed or updated, any already existing connections through the original mapping will be kept active until they formally terminate

• If a UDP entry is removed or updated, any already existing UDP connections through the original mapping will be cut off and completely removed

• On a failure to insert, update or remove a TCP/UDP entry, an error prompt will appear and the port forwarder will be reverted to its original state before the change occurred.