.. SPDX-License-Identifier: BSD-3-Clause
- Copyright(c) 2017 Intel Corporation.
+ Copyright(c) 2017-2021 Intel Corporation.
-DPDK pdump Library and pdump Tool
-=================================
+DPDK packet capture libraries and tools
+=======================================
This document describes how the Data Plane Development Kit (DPDK) Packet
Capture Framework is used for capturing packets on DPDK ports. It is intended
for users of DPDK who want to know more about the Packet Capture feature and
for those who want to monitor traffic on DPDK-controlled devices.
-The DPDK packet capture framework was introduced in DPDK v16.07. The DPDK
-packet capture framework consists of the DPDK pdump library and DPDK pdump
-tool.
-
+The DPDK packet capture framework was introduced in DPDK v16.07
+and enhanced in 21.11.
+The DPDK packet capture framework consists of the libraries
+for collecting packets ``librte_pdump``
+and writing packets to a file ``librte_pcapng``.
+There are two sample applications: ``dpdk-dumpcap`` and older ``dpdk-pdump``.
Introduction
------------
-The :ref:`librte_pdump <pdump_library>` library provides the APIs required to
-allow users to initialize the packet capture framework and to enable or
-disable packet capture. The library works on a client/server model and its
-usage is recommended for debugging purposes.
-
-The :ref:`dpdk-pdump <pdump_tool>` tool is developed based on the
-``librte_pdump`` library. It runs as a DPDK secondary process and is capable
-of enabling or disabling packet capture on DPDK ports. The ``dpdk-pdump`` tool
-provides command-line options with which users can request enabling or
-disabling of the packet capture on DPDK ports.
-
-The application which initializes the packet capture framework will act as a
-server and the application that enables or disables the packet capture will
-act as a client. The server sends the Rx and Tx packets from the DPDK ports
-to the client.
-
-In DPDK the ``testpmd`` application can be used to initialize the packet
-capture framework and act as a server, and the ``dpdk-pdump`` tool acts as a
-client. To view Rx or Tx packets of ``testpmd``, the application should be
-launched first, and then the ``dpdk-pdump`` tool. Packets from ``testpmd``
-will be sent to the tool, which then sends them on to the Pcap PMD device and
-that device writes them to the Pcap file or to an external interface depending
-on the command-line option used.
+The :doc:`librte_pdump <../prog_guide/pdump_lib>` library provides the API
+required to allow users to initialize the packet capture framework
+and to enable or disable packet capture.
+The library works on a multi-process communication model
+and its usage is recommended for debugging purposes.
+
+The :doc:`librte_pcapng <../prog_guide/pcapng_lib>` library provides the API
+to format packets and write them to a file in Pcapng format.
+
+The :doc:`dpdk-dumpcap <../tools/dumpcap>` is a tool that captures packets in
+like Wireshark dumpcap does for Linux.
+It runs as a DPDK secondary process and captures packets
+from one or more interfaces and writes them to a file in Pcapng format.
+The ``dpdk-dumpcap`` tool is designed to take
+most of the same options as the Wireshark ``dumpcap`` command.
+
+Without any options it will use the packet capture framework
+to capture traffic from the first available DPDK port.
+
+The ``dpdk-testpmd`` application can be used to initialize
+the packet capture framework and acts as a server,
+and the ``dpdk-dumpcap`` tool acts as a client.
+To view Rx or Tx packets of ``dpdk-testpmd``,
+the application should be launched first,
+and then the ``dpdk-dumpcap`` tool.
+Packets from ``dpdk-testpmd`` will be sent to the tool,
+and then to the Pcapng file.
Some things to note:
-* The ``dpdk-pdump`` tool can only be used in conjunction with a primary
+* All tools using ``librte_pdump`` can only be used in conjunction with a primary
application which has the packet capture framework initialized already. In
dpdk, only ``testpmd`` is modified to initialize packet capture framework,
- other applications remain untouched. So, if the ``dpdk-pdump`` tool has to
+ other applications remain untouched. So, if the ``dpdk-dumpcap`` tool has to
be used with any application other than the testpmd, the user needs to
explicitly modify that application to call the packet capture framework
initialization code. Refer to the ``app/test-pmd/testpmd.c`` code and look
for ``pdump`` keyword to see how this is done.
-* The ``dpdk-pdump`` tool depends on the libpcap based PMD which is disabled
- by default in the build configuration files, owing to an external dependency
- on the libpcap development files. Once the libpcap development files are
- installed, the libpcap based PMD can be enabled by setting
- ``CONFIG_RTE_LIBRTE_PMD_PCAP=y`` and recompiling the DPDK.
+* The ``dpdk-pdump`` tool is an older tool
+ created as demonstration of ``librte_pdump`` library.
+ The ``dpdk-pdump`` tool provides more limited functionality
+ and depends on the Pcap PMD.
+ It is retained only for compatibility reasons;
+ users should use ``dpdk-dumpcap`` instead.
Test Environment
----------------
-The overview of using the Packet Capture Framework and the ``dpdk-pdump`` tool
+The overview of using the Packet Capture Framework and the ``dpdk-dumpcap`` utility
for packet capturing on the DPDK port in
:numref:`figure_packet_capture_framework`.
.. figure:: img/packet_capture_framework.*
- Packet capturing on a DPDK port using the dpdk-pdump tool.
-
-
-Configuration
--------------
-
-Modify the DPDK primary application to initialize the packet capture framework
-as mentioned in the above notes and enable the following config options and
-build DPDK::
-
- CONFIG_RTE_LIBRTE_PMD_PCAP=y
- CONFIG_RTE_LIBRTE_PDUMP=y
+ Packet capturing on a DPDK port using the dpdk-dumpcap utility.
Running the Application
-----------------------
-The following steps demonstrate how to run the ``dpdk-pdump`` tool to capture
+The following steps demonstrate how to run the ``dpdk-dumpcap`` tool to capture
Rx side packets on dpdk_port0 in :numref:`figure_packet_capture_framework` and
inspect them using ``tcpdump``.
#. Launch testpmd as the primary application::
- sudo ./app/testpmd -c 0xf0 -n 4 -- -i --port-topology=chained
+ sudo <build_dir>/app/dpdk-testpmd -c 0xf0 -n 4 -- -i --port-topology=chained
-#. Launch the pdump tool as follows::
+#. Launch the dpdk-dumpcap as follows::
- sudo ./build/app/dpdk-pdump -- \
- --pdump 'port=0,queue=*,rx-dev=/tmp/capture.pcap'
+ sudo <build_dir>/app/dpdk-dumpcap -w /tmp/capture.pcapng
#. Send traffic to dpdk_port0 from traffic generator.
- Inspect packets captured in the file capture.pcap using a tool
- that can interpret Pcap files, for example tcpdump::
+ Inspect packets captured in the file capture.pcapng using a tool
+ such as tcpdump or tshark that can interpret Pcapng files::
- $tcpdump -nr /tmp/capture.pcap
+ $ tcpdump -nr /tmp/capture.pcapng
reading from file /tmp/capture.pcap, link-type EN10MB (Ethernet)
11:11:36.891404 IP 4.4.4.4.whois++ > 3.3.3.3.whois++: UDP, length 18
11:11:36.891442 IP 4.4.4.4.whois++ > 3.3.3.3.whois++: UDP, length 18
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