A simple file transfer server and client application for CCNx built on the Portal API.

CCNx Simple File Transfer main page
CCNx.org

This is the CCNx Simple File Transfer tutorial (formerly CCNx Tutorial Demo), a very simple tutorial demonstrating an application using the CCNx Portal API, the CCN Software Stack and the CCN Metis Forwarder. It includes a set of programs, with source code, to serve files and retrieve files. Files are transferred using a basic 'chunked' protocol.

The point of the tutorial is to demonstrate how to use the CCNx Portal API. With this as an example, you should be able to understand how you could apply the API to your own application.

After building, the demo consists of 2 programs:

• ccnxSimpleFileTransfer_Server: Serves files out of a directory.
• ccnxSimpleFileTransfer_Client: Lists and retrieves files from the server.

The CCNx-Tutorial-Demo needs the Distillery CCNx distribution installed on the system. Please install the CCNx Distillery by downloading it from GitHub, here, and building it according to the instructions there.

To run the tutorial programs you will need a CCN forwarder (metis or athena) running. We'll use metis for this example, but either would work.

Start by running 'metis_daemon --capacity 0', then the ccnxSimpleFileTransfer_Server (to serve files) and then the ccnxSimpleFileTransfer_Client to access the server. It is recommended that you run the metis_daemon, ccnxSimpleFileTransfer_Server and ccnxSimpleFileTransfer_Client in different windows.

It is also recommended you run metis_daemon with the '--capacity 0' option to disable the cache on the forwarder. This makes experimenting more predictable, as all Interests will make it through to the ccnxSimpleFileTransfer_Server.

Compiling the tutorial:

1. Set the CCNX_HOME environment variable to the location of your Distillery build. In zsh, for example, it might look like this: export CCNX_HOME=/path/to/CCNx_Distillery/usr

2. If you ran 'make all' when you built the CCNx_Distillery distribution, you should already have the binaries in your $CCNX_HOME/bin directory.

   If they are not there, you can run 'make ccnxSimpleFileTransfer' from the CCNx_Distillery directory.

3. At this point, the compiled binaries for ccnxSimpleFileTransfer_Client and the ccnxSimpleFileTransfer_Server should be built and exist in $CCNX_HOME/bin

4. Start a forwarder. Do ONE of the following:

   4a. Start the CCNx forwarder, metis_daemon: $CCNX_HOME/bin/metis_daemon --capacity 0 &

   4b. Start the CCNx forwarder, athena: $CCNX_HOME/bin/athena -s 0 &

5. Run the ccnxSimpleFileTransfer_Server: Start the ccnxSimpleFileTransfer_Server, giving it a directory path as an argument. $CCNX_HOME/bin/ccnxSimpleFileTransfer_Server /path/to/a/directory/with/files/to/serve

6. Run the ccnxSimpleFileTransfer_Client to retrieve the list of files available from the ccnxSimpleFileTransfer_Server:

$CCNX_HOME/bin/ccnxSimpleFileTransfer_Client list # Will return a list of available files

Or, use the ccnxSimpleFileTransfer_Client to fetch a file from the ccnxSimpleFileTransfer_Server:

$CCNX_HOME/bin/ccnxSimpleFileTransfer_Client fetch <filename> # Will fetch a file using the chunked protocol

NOTE: Do not run the ccnxSimpleFileTransfer_Client in the same directory from which you are serving files as it will overwrite the source file and things will break.

• The ccnxSimpleFileTransfer_Client and ccnxSimpleFileTransfer_Server automatically create keystore files in their working directory.

• You can experiment with different chunk sizes by changing the value of ccnxSimpleFileTransferCommon_DefaultChunkSize, which is defined in ccnxSimpleFileTransfer_Common.c.

If you have any problems with the system, please discuss them on the developer mailing list: ccnx@ccnx.org. If the problem is not resolved via mailing list discussion, you can file tickets in the issue tracker.

For any questions please use the CCNx mailing list. ccnx@ccnx.org

This software is licensed under the PARC Software License. See LICENSE File.