CCN-Lite on RIOT

This application demonstrates how to use the Content-Centric Networking stack from CCN-Lite 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_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!
• ccnl_fib - modifies the FIB or shows its current state. If the command is called without parameters, it will print the current state of the FIB. It can also be called with the action parameters add or del to add or delete an entry from the FIB, e.g. ccnl_fib add /riot/peter/schmerzl ab:cd:ef:01:23:45:67:89 will add an entry for /riot/peter/schmerzl with ab:cd:ef:01:23:45:67:89 as a next hop and ccnl_fib del /riot/peter/schmerzl will remove the entry for /riot/peter/schmerzl and ccnl_fib del ab:cd:ef:01:23:45:67:89 will remove all entries with ab:cd:ef:01:23:45:67:89 as a next hop.

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 ccnl_cont /riot/peter/schmerzl Hello World! Hello RIOT! on the first terminal.
5. Add a FIB entry for this prefix on the second node, e.g. using the broadcast address: ccnl_fib add /riot/peter/schmerzl ff:ff:ff:ff:ff:ff
6. Enter ccnl_int /riot/peter/schmerzl in the second terminal.
7. See the content being displayed. Be happy!

Makefile configuration

The ccn-lite package provides several configuration options through defines that can be set in the application Makefile. The following options are mandatory for now:

• CFLAGS += -DUSE_LINKLAYER - use CCN directly over the link layer
• CFLAGS += -DCCNL_UAPI_H_ - tell ccn-lite to use the UAPI
• CFLAGS += -DUSE_SUITE_NDNTLV - use NDNTLV packet format
• CFLAGS += -DNEEDS_PREFIX_MATCHING - enables prefix matching
• CFLAGS += -DNEEDS_PACKET_CRAFTING - enable userspace packet creation Here's a list of some additional interesting options:
• CFLAGS += -DUSE_RONR - enable Reactive Optimistic Name-based Routing (RONR)
• CFLAGS += -DUSE_STATS - enable statistics
• CFLAGS += -DUSE_DUP_CHECK - enable duplicate checks when forwarding
• CFLAGS += -DUSE_HMAC256 - HMAC256 signed packets for CCNx1.0 encoding

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#L424 to `0x0801).