79 lines
2.1 KiB
ReStructuredText
79 lines
2.1 KiB
ReStructuredText
.. _sockets-echo-sample:
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Socket Echo Server
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##################
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Overview
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********
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The sockets/echo sample application for Zephyr implements an IPv4 TCP echo
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server using a BSD Sockets compatible API. The purpose of this sample is to
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show how it's possible to develop a sockets application portable to both
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POSIX and Zephyr. As such, it is kept minimal and supports only IPv4 and TCP.
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The source code for this sample application can be found at:
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:file:`samples/net/sockets/echo`.
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Requirements
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************
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- :ref:`networking_with_qemu`
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- or, a board with hardware networking
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Building and Running
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********************
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Build the Zephyr version of the sockets/echo application like this:
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.. zephyr-app-commands::
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:zephyr-app: samples/net/sockets/echo
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:board: <board_to_use>
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:goals: build
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:compact:
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``board_to_use`` defaults to ``qemu_x86``. In this case, you can run the
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application in QEMU using ``make run``. If you used another BOARD, you
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will need to consult its documentation for application deployment
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instructions. You can read about Zephyr support for specific boards in
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the documentation at :ref:`boards`.
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After the sample starts, it expects connections at 192.0.2.1, port 4242.
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The easiest way to connect is:
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.. code-block:: console
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$ telnet 192.0.2.1 4242
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After a connection is made, the application will echo back any line sent
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to it. The application implements a single-threaded server using blocking
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sockets, and thus can serve only one client connection at time. After the
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current client disconnects, the next connection can proceed.
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Running application on POSIX Host
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=================================
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The same application source code can be built for a POSIX system, e.g.
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Linux. (Note: if you look at the source, you will see that the code is
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the same except the header files are different for Zephyr vs POSIX.)
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To build for a host POSIX OS:
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.. code-block:: console
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$ make -f Makefile.posix
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To run:
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.. code-block:: console
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$ ./socket_echo
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To test:
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.. code-block:: console
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$ telnet 127.0.0.1 4242
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As can be seen, the behavior of the application is the same as the Zephyr
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version.
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