[dpdk-dev] [PATCH 2/3] docs:tun/tap PMD information

[Wiles, Keith]

Regards,
Keith

> On Sep 15, 2016, at 9:13 AM, Wiles, Keith <keith.wiles at intel.com> wrote:
> 
> self Nak - just noticed the copyright notices are wrong. 

My mistake I was looking at the wrong file the headers appear correct.

> 
> Regards,
> Keith
> 
>> On Sep 15, 2016, at 9:10 AM, Keith Wiles <keith.wiles at intel.com> wrote:
>> 
>> Signed-off-by: Keith Wiles <keith.wiles at intel.com>
>> ---
>> doc/guides/nics/tap.rst | 84 +++++++++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 84 insertions(+)
>> create mode 100644 doc/guides/nics/tap.rst
>> 
>> diff --git a/doc/guides/nics/tap.rst b/doc/guides/nics/tap.rst
>> new file mode 100644
>> index 0000000..072def8
>> --- /dev/null
>> +++ b/doc/guides/nics/tap.rst
>> @@ -0,0 +1,84 @@
>> +..  BSD LICENSE
>> +    Copyright(c) 2016 Intel Corporation. All rights reserved.
>> +    All rights reserved.
>> +
>> +    Redistribution and use in source and binary forms, with or without
>> +    modification, are permitted provided that the following conditions
>> +    are met:
>> +
>> +    * Redistributions of source code must retain the above copyright
>> +    notice, this list of conditions and the following disclaimer.
>> +    * Redistributions in binary form must reproduce the above copyright
>> +    notice, this list of conditions and the following disclaimer in
>> +    the documentation and/or other materials provided with the
>> +    distribution.
>> +    * Neither the name of Intel Corporation nor the names of its
>> +    contributors may be used to endorse or promote products derived
>> +    from this software without specific prior written permission.
>> +
>> +    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
>> +    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
>> +    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
>> +    A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
>> +    OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
>> +    SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
>> +    LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
>> +    DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
>> +    THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
>> +    (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
>> +    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
>> +
>> +Tun/Tap Poll Mode Driver
>> +========================================
>> +
>> +The rte_eth_tap.c PMD creates a device using TUN/TAP interfaces on the local
>> +host. The PMD allows for DPDK and the host to communicate using a raw device
>> +interface on the host and in the DPDK application.
>> +
>> +The device created is a TAP device, which sends/receives packet in a raw format
>> +with a L2 header. The usage for a TAP PMD is for connectivity to the local host
>> +using a TAP interface. When the TAP PMD is initialized it will create a number
>> +of tap devices in the host accessed via 'ifconfig -a' or 'ip' command. The
>> +commands can be used to assign and query the virtual like device.
>> +
>> +These TAP interfaces can be used with wireshark or tcpdump or Pktgen-DPDK along
>> +with being able to be used as a network connection to the DPDK application. The
>> +method enable one or more interfaces is to use the --vdev=eth_tap option on the
>> +DPDK application  command line. Each --vdev=eth_tap option give will create an
>> +interface named dtap0, dtap1, ... and so forth.
>> +
>> +.. code-block:: console
>> +
>> +   The interfaced name can be changed by adding the iface=foo0
>> +   e.g. --vedv=eth_tap,iface=foo0 --vdev=eth_tap,iface=foo1, ...
>> +
>> +.. code-block:: console
>> +
>> +   Also the speed of the interface can be changed from 10G to whatever number
>> +   needed, but the interface does not enforce that speed.
>> +   e.g. --vdev=eth_tap,iface=foo0,speed=25000
>> +
>> +After the DPDK application is started you can send and receive packets on the
>> +interface using the standard rx_burst/tx_burst APIs in DPDK. From the host point
>> +of view you can use any host tool like tcpdump, wireshark, ping, Pktgen and
>> +others to communicate with the DPDK application. The DPDK application may not
>> +understand network protocols like IPv4/6, UDP or TCP unless the application has
>> +been written to understand these protocols.
>> +
>> +If you need the interface as a real network interface meaning running and has
>> +a valid IP address then you can do this with the following commands:
>> +
>> +.. code-block:: console
>> +
>> +   sudo ip link set dtap0 up; sudo ip addr add 192.168.0.250/24 dev dtap0
>> +   sudo ip link set dtap1 up; sudo ip addr add 192.168.1.250/24 dev dtap1
>> +
>> +Please change the IP addresses as you see fit.
>> +
>> +If routing is enabled on the host you can also communicate with the DPDK App
>> +over the internet via a standard socket layer application as long as you account
>> +for the protocol handing in the application.
>> +
>> +If you have a Network Stack in your DPDK application or something like it you
>> +can utilize that stack to handle the network protocols. Plus you would be able
>> +to address the interface using an IP address assigned to the internal interface.
>> -- 
>> 2.8.0.GIT
>> 
>