.. zephyr:code-sample:: sockets-echo-client :name: Echo client (advanced) :relevant-api: bsd_sockets tls_credentials Implement a client that sends IP packets, waits for data to be sent back, and verifies it. Overview ******** The echo-client sample application for Zephyr implements a UDP/TCP client that will send IPv4 or IPv6 packets, wait for the data to be sent back, and then verify it matches the data that was sent. The source code for this sample application can be found at: :zephyr_file:`samples/net/sockets/echo_client`. Requirements ************ - :ref:`networking_with_host` Building and Running ******************** There are multiple ways to use this application. One of the most common usage scenario is to run echo-client application inside QEMU. This is described in :ref:`networking_with_qemu`. There are configuration files for different boards and setups in the echo-client directory: - :file:`prj.conf` Generic config file, normally you should use this. - :file:`overlay-ot.conf` This overlay config enables support for OpenThread. - :file:`overlay-802154.conf` This overlay config enables support for native IEEE 802.15.4 connectivity. Note, that by default IEEE 802.15.4 L2 uses unacknowledged communication. To improve connection reliability, acknowledgments can be enabled with shell command: ``ieee802154 ack set``. - :file:`overlay-qemu_802154.conf` This overlay config enables support for two QEMU's when simulating IEEE 802.15.4 network that are connected together. - :file:`overlay-tls.conf` This overlay config enables support for TLS. Build echo-client sample application like this: .. zephyr-app-commands:: :zephyr-app: samples/net/sockets/echo_client :board: :conf: :goals: build :compact: Example building for the nrf52840dk/nrf52840 with OpenThread support: .. zephyr-app-commands:: :zephyr-app: samples/net/sockets/echo_client :host-os: unix :board: nrf52840dk/nrf52840 :conf: "prj.conf overlay-ot.conf" :goals: run :compact: Example building for the IEEE 802.15.4 RF2XX transceiver: .. zephyr-app-commands:: :zephyr-app: samples/net/sockets/echo_client :host-os: unix :board: [samr21_xpro | sam4s_xplained | sam_v71_xult/samv71q21] :gen-args: -DEXTRA_CONF_FILE=overlay-802154.conf :goals: build flash :compact: In a terminal window you can check if communication is happen: .. code-block:: console $ minicom -D /dev/ttyACM1 Enabling TLS support ==================== Enable TLS support in the sample by building the project with the ``overlay-tls.conf`` overlay file enabled, for example, using these commands: .. zephyr-app-commands:: :zephyr-app: samples/net/sockets/echo_client :board: qemu_x86 :conf: "prj.conf overlay-tls.conf" :goals: build :compact: An alternative way is to specify ``-DEXTRA_CONF_FILE=overlay-tls.conf`` when running ``west build`` or ``cmake``. The certificate and private key used by the sample can be found in the sample's ``src`` directory. The default certificates used by Socket Echo Client and :zephyr:code-sample:`sockets-echo-server` enable establishing a secure connection between the samples. SOCKS5 proxy support ==================== It is also possible to connect to the echo-server through a SOCKS5 proxy. To enable it, use ``-DEXTRA_CONF_FILE=overlay-socks5.conf`` when running ``west build`` or ``cmake``. By default, to make the testing easier, the proxy is expected to run on the same host as the echo-server in Linux host. To start a proxy server, for example a builtin SOCKS server support in ssh can be used (-D option). Use the following command to run it on your host with the default port: For IPv4 proxy server: .. code-block:: console $ ssh -N -D 0.0.0.0:1080 localhost For IPv6 proxy server: .. code-block:: console $ ssh -N -D [::]:1080 localhost Run both commands if you are testing IPv4 and IPv6. To connect to a proxy server that is not running under the same IP as the echo-server or uses a different port number, modify the following values in echo_client/src/tcp.c. .. code-block:: c #define SOCKS5_PROXY_V4_ADDR IPV4_ADDR #define SOCKS5_PROXY_V6_ADDR IPV6_ADDR #define SOCKS5_PROXY_PORT 1080 Running echo-server in Linux Host ================================= There is one useful testing scenario that can be used with Linux host. Here echo-client is run in QEMU and echo-server is run in Linux host. To use QEMU for testing, follow the :ref:`networking_with_qemu` guide. In a terminal window: .. code-block:: console $ sudo ./echo-server -i tap0 Run echo-client application in QEMU: .. zephyr-app-commands:: :zephyr-app: samples/net/sockets/echo_client :host-os: unix :board: qemu_x86 :conf: "prj.conf overlay-linux.conf" :goals: run :compact: Note that echo-server must be running in the Linux host terminal window before you start the echo-client application in QEMU. Exit QEMU by pressing :kbd:`CTRL+A` :kbd:`x`. You can verify TLS communication with a Linux host as well. See https://github.com/zephyrproject-rtos/net-tools documentation for information on how to test TLS with Linux host samples. See the :zephyr:code-sample:`sockets-echo-server` documentation for an alternate way of running, with the echo-client on the Linux host and the echo-server in QEMU. OpenThread RCP+Zephyr HOST (SPINEL connection via UART) ======================================================= Prerequisites: -------------- - Build ``echo-server`` for HOST PC (x86_64) (https://github.com/zephyrproject-rtos/net-tools) SHA1:1c4fdba .. code-block:: console $ make echo-server - Program nRF RCP from Nordic nrf SDK (v2.7.0): .. code-block:: console (v2.7.0) ~/ncs$ west build -p always -b nrf21540dk/nrf52840 -S logging nrf/samples/openthread/coprocessor - Build mimxrt1020_evk HOST (Zephyr): .. zephyr-app-commands:: :zephyr-app: samples/net/sockets/echo_client :board: mimxrt1020_evk :conf: "prj.conf overlay-ot-rcp-host-uart.conf" :goals: build :compact: And flash .. code-block:: console $ west flash -r pyocd -i 0226000047784e4500439004d9170013e56100009796990 - Connect the nRF RCP with IMXRT1020 (HOST) via UART .. code-block:: c /* * imxrt1020_evk -> HOST * nRF21540-DK -> RCP (nrf/samples/openthread/coprocessor) * LPUART2 used for communication: * nRF21540 (P6) P0.08 RXD -> IMXRT1020-EVK (J17) D1 (GPIO B1 08) (TXD) * nRF21540 (P6) P0.07 CTS -> IMXRT1020-EVK (J19) D8 (GPIO B1 07) (RTS) * nRF21540 (P6) P0.06 TXD -> IMXRT1020-EVK (J17) D0 (GPIO B1 09) (RXD) * nRF21540 (P6) P0.05 RTS -> IMXRT1020-EVK (J17) D7 (GPIO B1 06) (CTS) */ - Install the OTBR (OpenThread Border Router) docker container on your HOST PC (x86_64) Follow steps from https://docs.nordicsemi.com/bundle/ncs-2.5.1/page/nrf/protocols/thread/tools.html#running_otbr_using_docker **Most notable ones:** 1. Create ``otbr0`` network bridge to have access to OT network from HOST Linux PC .. code-block:: console sudo docker network create --ipv6 --subnet fd11:db8:1::/64 -o com.docker.network.bridge.name=otbr0 otbr 2. Pull docker container for OTBR: .. code-block:: console docker pull nrfconnect/otbr:84c6aff 3. Start the docker image: .. code-block:: console sudo modprobe ip6table_filter sudo docker run -it --rm --privileged --name otbr --network otbr -p 8080:80 --sysctl "net.ipv6.conf.all.disable_ipv6=0 net.ipv4.conf.all.forwarding=1 net.ipv6.conf.all.forwarding=1" --volume /dev/ttyACM5:/dev/radio nrfconnect/otbr:84c6aff --radio-url spinel+hdlc+uart:///dev/radio?uart-baudrate=1000000 4. Add proper routing (``fd11:22::/64`` are the IPv6 addresses - On-Mesh - which allow accessing the OT devices) on HOST PC (x86_64) .. code-block:: console sudo ip -6 route add fd11:22::/64 dev otbr0 via fd11:db8:1::2 And the output for on-OT address: .. code-block:: console ip route get fd11:22:0:0:5188:1678:d0c0:6893 fd11:22::5188:1678:d0c0:6893 from :: via fd11:db8:1::2 dev otbr0 src fd11:db8:1::1 metric 1024 pref medium 5. Start the console to the docker image: .. code-block:: console sudo docker exec -it otbr /bin/bash Test with e.g. .. code-block:: console ot-ctl router table ot-ctl ipaddr Configure OTBR -------------- On the HOST PC's webbrowser: http://localhost:8080/ Go to ``Form`` and leave default values - e.g: * Network Key: ``00112233445566778899aabbccddeeff`` * On-Mesh Prefix: ``fd11:22::`` * Channel: ``15`` to "FORM" the OT network. *Note:* The "On-Mesh Prefix" shall match the one setup in ``otbr0`` routing. Configure RCP (nRF21540-DK) + OT HOST (mimxrt1020) -------------------------------------------------- .. code-block:: console ot factoryreset ot dataset networkkey 00112233445566778899aabbccddeeff ot ifconfig up In the HOST PC www webpage interface please: Commission -> Joiner PSKd* set to ``J01NME`` -> START COMMISSION .. code-block:: console ot joiner start J01NME ot thread start The ``ot ipaddr`` shall show IPv6 address starting from ``fd11:22:0:0:``. This one can be accessed from HOST's PC network (via e.g. ``ping -6 fd11:22:0:0:e8bf:266b:63ca:eff4``). Start ``echo-server`` on HOST PC (x86-64) ----------------------------------------- .. code-block:: console ./echo-server -i otbr0