# CCN-Lite on RIOT

This application demonstrates how to use the Content-Centric Networking stack
from [CCN-Lite](http://www.ccn-lite.net/) on RIOT. In the current state you can
use only one packet format, `ndn2013`, and only relay over the link-layer
(Ethernet, IEEE~802.15.4 or what else is supported by your network device).

## The shell commands

RIOT provides three shell to interact with the CCN-Lite stack:
* `ccnl_open` - opens and configures a network device to be used for CCN-Lite.
                It expects one parameter specifying the PID of the network
                device. (You can figure out the PID of your network device(s)
                by calling `ifconfig`.) In this example, this should always be
                3, hence, calling `ccnl_open 3` should work. (If you specify an
                incorrect ID, you should get an error message.) You have to
                call this command, before you can actually send or receive
                anything.
* `ccnl_int` - generates and sends out an Interest. The command expects one
               mandatory and one optional parameter. The first parameter
               specifies the exact name (or a prefix) to request, the second
               parameter specifies the link-layer address of the relay to use.
               If the second parameter is omitted, the Interest will be
               broadcasted. You may call it like this:
               `ccnl_int /riot/peter/schmerzl b6:e5:94:26:ab:da`
* `ccnl_cont` - generates and populates Content. The command expects one
               mandatory and one optional parameter. The first parameter
               specifies the name of the content to be created, the second
               parameter specifies the content itself. The second parameter may
               include spaces, e.g. you can call:
               `ccnl_cont /riot/peter/schmerzl Hello World! Hello RIOT!`

## Example setup

An example usage of this application could be setup like this:
1. Open a terminal window, navigate to the RIOT directory, and enter
   `dist/tools/tapsetup/tapsetup -c`.
2. Open a second terminal window and navigate to this directory in both of
   windows.
3. Call `make -B clean all term` in the first terminal and `PORT=tap1 make
   term` in the second one.
4. Enter `open 3` in both terminals.
5. Enter `ccnl_cont /riot/peter/schmerzl Hello World! Hello RIOT!` on the first
   terminal.
6. Enter `ccnl_int /riot/peter/schmerzl` in the second terminal.
7. See the content being displayed. Be happy!

## Wireshark dissector

One can use the Wireshark dissector from the named-data project
(https://github.com/named-data/ndn-tools/tree/master/tools/dissect-wireshark)
for analyzing the traffic in Wireshark.

However, please note, that - in order to be compatible with the default
CCN-Lite upstream configuration - a different Ethertype (`0x0801` instead of
`0x8624`) is used.

The simplest way to get this working is to copy the `ndn.lua` file into your
local Wireshark plugin directory (e.g. `$HOME/.wireshark/plugins`) and update
https://github.com/named-data/ndn-tools/blob/master/tools/dissect-wireshark/ndn.lua#L408
to `0x0801).