278f945402
The librte_pdump library provides a framework for packet capturing in dpdk. The library provides set of APIs to initialize the packet capture framework, to enable or disable the packet capture, and to uninitialize it. The librte_pdump library works on a client/server model. The server is responsible for enabling or disabling the packet capture and the clients are responsible for requesting the enabling or disabling of the packet capture. Enabling APIs are supported with port, queue, ring and mempool parameters. Applications should pass on this information to get the packets from the dpdk ports. For enabling requests from applications, library creates the client request containing the mempool, ring, port and queue information and sends the request to the server. After receiving the request, server registers the Rx and Tx callbacks for all the port and queues. After the callbacks registration, registered callbacks will get the Rx and Tx packets. Packets then will be copied to the new mbufs that are allocated from the user passed mempool. These new mbufs then will be enqueued to the application passed ring. Applications need to dequeue the mbufs from the rings and direct them to the devices like pcap vdev for viewing the packets outside of the dpdk using the packet capture tools. For disabling requests, library creates the client request containing the port and queue information and sends the request to the server. After receiving the request, server removes the Rx and Tx callback for all the port and queues. Signed-off-by: Reshma Pattan <reshma.pattan@intel.com> Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
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6.4 KiB
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124 lines
6.4 KiB
ReStructuredText
.. BSD LICENSE
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Copyright(c) 2016 Intel Corporation. All rights reserved.
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the
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distribution.
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* Neither the name of Intel Corporation nor the names of its
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.. _pdump_library:
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The librte_pdump Library
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========================
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The ``librte_pdump`` library provides a framework for packet capturing in DPDK.
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The library does the complete copy of the Rx and Tx mbufs to a new mempool and
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hence it slows down the performance of the applications, so it is recommended
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to use this library for debugging purposes.
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The library provides the following APIs to initialize the packet capture framework, to enable
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or disable the packet capture, and to uninitialize it:
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* ``rte_pdump_init()``:
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This API initializes the packet capture framework.
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* ``rte_pdump_enable()``:
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This API enables the packet capture on a given port and queue.
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Note: The filter option in the API is a place holder for future enhancements.
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* ``rte_pdump_enable_by_deviceid()``:
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This API enables the packet capture on a given device id (``vdev name or pci address``) and queue.
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Note: The filter option in the API is a place holder for future enhancements.
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* ``rte_pdump_disable()``:
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This API disables the packet capture on a given port and queue.
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* ``rte_pdump_disable_by_deviceid()``:
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This API disables the packet capture on a given device id (``vdev name or pci address``) and queue.
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* ``rte_pdump_uninit()``:
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This API uninitializes the packet capture framework.
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* ``rte_pdump_set_socket_dir()``:
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This API sets the server and client socket paths.
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Note: This API is not thread-safe.
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Operation
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---------
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The ``librte_pdump`` library works on a client/server model. The server is responsible for enabling or
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disabling the packet capture and the clients are responsible for requesting the enabling or disabling of
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the packet capture.
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The packet capture framework, as part of its initialization, creates the pthread and the server socket in
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the pthread. The application that calls the framework initialization will have the server socket created,
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either under the path that the application has passed or under the default path i.e. either ``/var/run`` for
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root user or ``$HOME`` for non root user.
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Applications that request enabling or disabling of the packet capture will have the client socket created either under
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the path that the application has passed or under the default path i.e. either ``/var/run/`` for root user or ``$HOME``
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for not root user to send the requests to the server.
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The server socket will listen for client requests for enabling or disabling the packet capture.
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Implementation Details
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----------------------
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The library API ``rte_pdump_init()``, initializes the packet capture framework by creating the pthread and the server
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socket. The server socket in the pthread context will be listening to the client requests to enable or disable the
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packet capture.
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The library APIs ``rte_pdump_enable()`` and ``rte_pdump_enable_by_deviceid()`` enables the packet capture.
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On each call to these APIs, the library creates a separate client socket, creates the "pdump enable" request and sends
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the request to the server. The server that is listening on the socket will take the request and enable the packet capture
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by registering the Ethernet RX and TX callbacks for the given port or device_id and queue combinations.
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Then the server will mirror the packets to the new mempool and enqueue them to the rte_ring that clients have passed
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to these APIs. The server also sends the response back to the client about the status of the request that was processed.
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After the response is received from the server, the client socket is closed.
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The library APIs ``rte_pdump_disable()`` and ``rte_pdump_disable_by_deviceid()`` disables the packet capture.
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On each call to these APIs, the library creates a separate client socket, creates the "pdump disable" request and sends
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the request to the server. The server that is listening on the socket will take the request and disable the packet
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capture by removing the Ethernet RX and TX callbacks for the given port or device_id and queue combinations. The server
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also sends the response back to the client about the status of the request that was processed. After the response is
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received from the server, the client socket is closed.
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The library API ``rte_pdump_uninit()``, uninitializes the packet capture framework by closing the pthread and the
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server socket.
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The library API ``rte_pdump_set_socket_dir()``, sets the given path as either server socket path
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or client socket path based on the ``type`` argument of the API.
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If the given path is ``NULL``, default path will be selected, i.e. either ``/var/run/`` for root user or ``$HOME``
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for non root user. Clients also need to call this API to set their server socket path if the server socket
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path is different from default path.
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Use Case: Packet Capturing
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--------------------------
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The DPDK ``app/pdump`` tool is developed based on this library to capture packets in DPDK.
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Users can use this as an example to develop their own packet capturing tools.
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