tcpip.sgml

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</PROGRAMLISTING>
</SECT1>
<SECT1 id="net-common-standalone-tests">
<TITLE>Standalone Tests</TITLE>
<PROGRAMLISTING><EMPHASIS>socket_test</EMPHASIS> - trivial test of socket creation API 
<EMPHASIS>mbuf_test</EMPHASIS> - trivial test of mbuf allocation API</PROGRAMLISTING>
<PARA>These two do not communicate over the net; they just perform
simple API tests then exit.</PARA>
<PROGRAMLISTING><EMPHASIS>ftp_test</EMPHASIS>      - simple FTP test, connects to &ldquo;server&rdquo;</PROGRAMLISTING>
<PARA>This test initializes the interface(s) then connects to the
FTP server on the &ldquo;server&rdquo; machine for for each
active interface in turn, confirms that the connection was successful,
disconnects and exits.  This tests interworking with the server.</PARA>
<PROGRAMLISTING><EMPHASIS>ping_test</EMPHASIS>      - pings &ldquo;server&rdquo; and non-existent host to test timeout</PROGRAMLISTING>
<PARA>This test initializes the interface(s) then pings the server
machine in the standard way, then pings address &ldquo;32 up&rdquo; from
the server in the expectation that there is no machine there.  This
confirms that the successful ping is not a false positive, and tests
the receive timeout.  If there is such a machine, of course the
2nd set of pings succeeds, confirming that we can talk to a machine
not previously mentioned by configuration or by bootp. It then does
the same thing on the other interface, eth1.</PARA>

<PARA>If IPv6 is enabled, the program will also ping to the address it
last received a router advertisement from. Also a ping will be made to
that address plus 32, in a similar way the the IPv4 case.</PARA>

<PROGRAMLISTING><EMPHASIS>dhcp_test</EMPHASIS>    - ping test, but also manipulates DHCP leases</PROGRAMLISTING>
<PARA>This test is very similar to the ping test, but in addition,
provided the network package is not configured to do this automatically,
it manually relinquishes and reclaims DHCP leases for all available
interfaces. This tests the external API to DHCP. See section below
describing this.</PARA>
<PROGRAMLISTING><EMPHASIS>flood</EMPHASIS>        - a flood ping test; use with care</PROGRAMLISTING>
<PARA>This test performs pings on all interfaces as quickly as possible,
and only prints status information periodically. Flood pinging is
bad for network performance; so do not use this test on general
purpose networks unless protected by a switch.</PARA>
</SECT1>
<SECT1 id="net-common-performance-test">
<TITLE>Performance Test</TITLE>
<PROGRAMLISTING><EMPHASIS>tcp_echo</EMPHASIS>      - data forwarding program for performance test</PROGRAMLISTING>
<PARA><command>tcp_echo</command> is one
part of the standard performance test we use.  The other parts are
host programs <LITERAL>tcp_source</LITERAL> and <LITERAL>tcp_sink</LITERAL>.
 To make these (under your <emphasis>HOST</emphasis> system) cd to the tests source directory in
the eCos repository and type &ldquo;<LITERAL>make -f make.host</LITERAL>&rdquo; -
this should build <LITERAL>tcp_source</LITERAL> and <LITERAL>tcp_sink</LITERAL>.</PARA>
<PARA>The host program &ldquo;<LITERAL>tcp_source</LITERAL>&rdquo; sends
data to the target.  On the target, &ldquo;<LITERAL>tcp_echo</LITERAL>&rdquo; sends
it onwards to &ldquo;<LITERAL>tcp_sink</LITERAL>&rdquo; running
on your host.  So the target must receive and send on all the data that <LITERAL>tcp_source</LITERAL> sends
it; the time taken for this is measured and the data rate is calculated.</PARA>
<PARA>To invoke the test, first start <LITERAL>tcp_echo</LITERAL> on
the target board and wait for it to become quiescent - it will report
work to calibrate a CPU load which can be used to simulate real
operating conditions for the stack.</PARA>
<PARA>Then on your host machine, in one terminal window, invoke <LITERAL>tcp_sink</LITERAL> giving
it the IP address (or hostname) of one interface of the target board.
 For example &ldquo;<LITERAL>tcp_sink 10.130.39.66</LITERAL>&rdquo;.
 <LITERAL>tcp_echo</LITERAL> on the target
will print something like &ldquo;<LITERAL>SINK connection
from 10.130.39.13:1143</LITERAL>&rdquo; when <LITERAL>tcp_sink</LITERAL> is
correctly invoked.</PARA>
<PARA>Next, in another host terminal window, invoke <LITERAL>tcp_source</LITERAL>,
giving it the IP address (or hostname) of an interface of the target
board, and optionally a background load to apply to the target while
the test runs.  For example, &ldquo;<LITERAL>tcp_source
194.130.39.66</LITERAL>&rdquo; to run the test with no
additional target CPU load, or &ldquo;<LITERAL>tcp_source
194.130.39.66 85</LITERAL>&rdquo; to load it up to 85% used.
 The target load must be a multiple of 5.  <LITERAL>tcp_echo</LITERAL> on
the target will print something like &ldquo;<LITERAL>SOURCE
connection from 194.130.39.13:1144</LITERAL>&rdquo; when
tcp_source is correctly invoked.</PARA>
<PARA>You can connect tcp_sink to one target interface
and tcp_source to another, or both to the same interface.
 Similarly, you can run <LITERAL>tcp_sink</LITERAL> and <LITERAL>tcp_source</LITERAL> on
the same host machine or different ones.  TCP/IP and ARP
look after them finding one another, as intended.</PARA>
<PROGRAMLISTING><EMPHASIS>nc_test_master</EMPHASIS> - network characterization master
<EMPHASIS>nc_test_slave</EMPHASIS> - network characterization slave</PROGRAMLISTING>
<PARA>These tests talk to each other to measure network performance.
They can each run on either a test target or a host computer
given some customization to your local environment. As provided, <literal>nc_test_slave</literal> must
run on the test target, and <literal>nc_test_master</literal> must
be run on a host computer, and be given the test target's
IP address or hostname.</PARA>
<PARA>The tests print network performance for various packet sizes
over UDP and TCP, versus various additional CPU loads on the target.</PARA>
<PARA>
The programs <PROGRAMLISTING><EMPHASIS>nc6_test_slave</EMPHASIS>
<EMPHASIS>nc6_test_master</EMPHASIS></PROGRAMLISTING>
are additional forms which support both IPv4 and IPv6 addressing.
</PARA>
</SECT1>
<SECT1 id="net-common-interactive-tests">
<TITLE>Interactive Tests</TITLE>
<PROGRAMLISTING><EMPHASIS>server_test</EMPHASIS> - a very simple server example</PROGRAMLISTING>
<PARA>This test simply awaits a connection on port 7734 and after
accepting a connection, gets a packet (with a timeout of a few seconds)
and prints it. </PARA>
<PARA>The connection is then closed. We then loop to await the next
connection, and so on. To use it, telnet to the target on port 7734
then type something (quickly!)</PARA>
<screen>% telnet 172.16.19.171 7734 
Hello target board</screen>
<PARA>and the test program will print something like:</PARA>
<screen>connection from 172.16.19.13:3369 
buf = "Hello target board"</screen>

<PROGRAMLISTING><EMPHASIS>ga_server_test</EMPHASIS> - another very simple server example</PROGRAMLISTING>
<PARA>This is a variation on the <EMPHASIS>ga_server_test</EMPHASIS> test
with the difference being that it uses the <FUNCTION>getaddrinfo</FUNCTION>
function to set up its addresses.  On a system with IPv6 enabled, it will
listen on port 7734 for a TCP connection via either IPv4 or IPv6.
</PARA>

<PROGRAMLISTING><EMPHASIS>tftp_client_test</EMPHASIS> - performs a tftp get and put from/to &ldquo;server&rdquo;</PROGRAMLISTING>
<PARA>This is only partially interactive.  You need to set things
up on the &ldquo;server&rdquo; in order for this to work,
and you will need to look at the server afterwards to confirm that all
was well.</PARA>
<PARA>For each interface in turn, this test attempts to read by
tftp from the server, a file called
<filename>tftp_get</filename>
and
prints the status and contents it read (if any).  It then writes
the same data to a file called
<filename>tftp_put</filename>
on
the same server.</PARA>
<PARA>In order for this to succeed, both files must already exist.
 The TFTP protocol does not require that a WRQ request _create_ a
file, just that it can write it.  The TFTP server on Linux certainly
will only allow writes to an existing file, given the appropriate
permission.  Thus, you need to have these files in place, with proper permission,
before running the test.</PARA>
<PARA>The conventional place for the tftp server to operate in LINUX
is /tftpboot/; you will likely need root privileges
to create files there. The data contents of
<filename>tftp_get</filename>
can
be anything you like, but anything very large will waste lots of
time printing it on the test&rsquo;s stdout, and anything above
32kB will cause a buffer overflow and unpredictable failure.</PARA>
<PARA>Creating an empty tftp_put file (eg. by copying /dev/null
to it) is neatest.  So before the test you should have something
like:</PARA>
<PROGRAMLISTING>-rw-rw-rw- 1 root        1076 May  1 11:39 tftp_get
-rw-rw-rw- 1 root        0 May  1 15:52 tftp_put </PROGRAMLISTING>
<PARA>note that both files have public permissions wide open.  After
running the test,
<filename>tftp_put</filename>
should
be a copy of
<filename>tftp_get</filename>.</PARA>
<PROGRAMLISTING>-rw-rw-rw-  1 root       1076 May  1 11:39 tftp_get
-rw-rw-rw-  1 root       1076 May  1 15:52 tftp_put

</PROGRAMLISTING>

<PARA>If the configuration contains IPv6 support, the test program
will also use IPv6. It will attempt to put/get the files listed above
from the address it last received a routers solicit from.</PARA>

<PROGRAMLISTING><EMPHASIS>tftp_server_test</EMPHASIS> - runs a tftp server for a short while</PROGRAMLISTING>
<PARA>This test is truly interactive, in that you can use a standard
tftp application to get and put files from the server, during the
5 minutes that it runs.  The dummy filesystem which underlies the
server initially contains one file, called &ldquo;uu&rdquo; which contains
part of a familiar text and some padding.  It also accommodates
creation of 3 further files of up to 1Mb in size and names of up
to 256 bytes.  Exceeding these limits will cause a buffer overflow
and unpredictable failure.</PARA>
<PARA>The dummy filesystem is an implementation of the generic API
which allows a true filesystem to be attached to the tftp server
in the network stack.</PARA>
<PARA>We have been testing the tftp server by running the test on
the target board, then using two different host computers connecting
to the different target interfaces, putting a file from each, getting
the &ldquo;uu&rdquo; file, and getting the file from the other computer.
 This verifies that data is preserved during the transfer as well
as interworking with standard tftp applications.</PARA>
</SECT1>
<SECT1 id="net-common-maintenance-tools">
<TITLE>Maintenance Tools </TITLE>
<PROGRAMLISTING><EMPHASIS>set_mac_address</EMPHASIS> - set MAC address(es) of interfaces in NVRAM</PROGRAMLISTING>
<PARA>This program makes an example <function>ioctl()</function> call
<acronym>SIOCSIFHWADDR</acronym> 
&ldquo;Socket IO Set InterFace HardWare ADDRess&rdquo;
to set the MAC address on targets
where this is supported and enabled in the configuration. You must
edit the source to choose a MAC address and further edit it to allow
this very dangerous operation. Not all ethernet drivers support
this operation, because most ethernet hardware does not support
it &mdash; or it comes pre-set from the factory.
<emphasis>Do not use this program.</emphasis></PARA>
</SECT1>
</CHAPTER>
<CHAPTER id="net-common-support">
<title>Support Features</title>
<SECT1 id="net-common-tftp">
<TITLE>TFTP</TITLE>
<PARA>The TFTP client and server are described in
<filename>tftp_support.h</filename>;
</PARA>
<PARA>The TFTP client has and new and an older, deprecated, API. The
new API works for both IPv4 and IPv6 where as the deprecated API is
IPv4 only.
</PARA>
<PARA>
The new API is as follows: