libcoap

Example of libcoap running in Zephyr
====================================
If the Zephyr project environment is already installed outside of the libcoap
environment, then ZEPHYR_PROJECT need to be set to where it is already installed
(i.e export ZEPHYR_PROJECT=~/zephyrproject ).

If ZEPHYR_PROJECT is not set, then this defaults in this Makefile to the directory
zephyrproject under the examples/zephyr directory.

To build the coap-client example, do

    $ make

The executable gets built in ${ZEPHYR_PROJECT}/zephyr/build/zephyr/zephyr.exe
which is then copied to coap-client in the examples/zephyr directory.

./coap-client does a 'GET coaps://libcoap-net' using PSK with logging enabled.

For using the native_sim board using Linux, you may need to do something like
the following (ens32 is the external interface name, your environment may
be different)

    $ sudo ${ZEPHYR_PROJECT}/tools/net-tools/net-setup.sh start
    $ sudo iptables -t nat -A POSTROUTING -o ens32 -j MASQUERADE
    $ sudo sysctl -w net.ipv4.conf.all.forwarding=1

so that ./coap-client is able to route traffic out onto the internet and get
responses.