nanocoap server example

This application is meant to get you started with implementing a CoAP server on RIOT. It uses the GNRC network stack through RIOT's sock API.

Usage

To try out the server on native, compile it with

$ make all

Then, create a tap interface (to which RIOT will connect):

$ sudo ip tuntap add tap0 mode tap user ${USER}
$ sudo ip link set tap0 up

Run the resulting RIOT binary by invoking:

$ make term

The application is now listening on all it's configured IP addresses.

Now find out its link_layer address:

$ make term
/home/aabadie/riot/examples/nanocoap_server/bin/native/nanocoapcoap_server.elf tap0
RIOT native interrupts/signals initialized.
LED_GREEN_OFF
LED_RED_ON
RIOT native board initialized.
RIOT native hardware initialization complete.

main(): This is RIOT! (Version: 2015.12-devel-632-g8f451-booze-master)
RIOT nanocoap example application
Waiting for address autoconfiguration...
Configured network interfaces:
Iface  5   HWaddr: 96:3c:18:1e:26:f7

           MTU:1500  HL:64  RTR  RTR_ADV
           Source address length: 6
           Link type: wired
           inet6 addr: ff02::1/128  scope: local [multicast]
           inet6 addr: fe80::e42a:1aff:feca:10ec/64  scope: local
           inet6 addr: ff02::1:ffca:10ec/128  scope: local [multicast]
           inet6 addr: ff02::2/128  scope: local [multicast]
           inet6 addr: 2001:db8:1:0:e42a:1aff:feca:10ec/64  scope: global

The link-layer address in this case is "fe80::e42a:1aff:feca:10ec", the only "scope: local" address set.

Testing

There are multiple external CoAP clients you can use to test the server on native.

libcoap CLI

(replace "fe80::e42a:1aff:feca:10ec" with your link-layer address)

# coap-client "coap://[fe80::e42a:1aff:feca:10ec%tap0]/riot/board"

Copper (Firefox Plugin)

The Copper plugin for Firefox provides you with a nice graphical interface, but getting it to work with RIOT requires a little setup.

Make sure you've installed

• The Firefox Copper plugin
• The Router Advertisement Daemon (radvd)

And build the application again using make.

Enter the following into your /etc/radvd.conf (if it doesn't exist yet, create one):

interface tap0
{
    AdvSendAdvert on;

    MinRtrAdvInterval 3;
    MaxRtrAdvInterval 10;

    AdvDefaultPreference low;

    prefix 2001:db8:1:0::/64
    {
        AdvOnLink on;
        AdvAutonomous on;
        AdvRouterAddr off;
    };
};

(you can use radvd -c to check for syntax errors)

and run

sudo radvd

Then, run the RIOT binary as usual:

make term

Note that the output listing all configured interfaces contains a globally scoped address, which you can now use to reach the RIOT instance via Copper. To do so, enter this:

coap://[2001:db8:1:0:e42a:1aff:feca:10ec]/riot/board

into your Firefox address bar, where you should replace 2001:db8:1:0:e42a:1aff:feca:10ec with your RIOT instance's address marked as "scope: global". If you click the big green GET button, the word native should appear in the Payload text box at the center of the GUI.

If this doesn't work, try manually adding a Global address to the tap0 interface:

sudo service radvd start
sudo ip address add 2001:db8:1::a/64 dev tap0
make term