xref: /dpdk/doc/guides/tools/pdump.rst (revision 089e5ed727a15da2729cfee9b63533dd120bd04c)
1..  SPDX-License-Identifier: BSD-3-Clause
2    Copyright(c) 2016 Intel Corporation.
3
4.. _pdump_tool:
5
6dpdk-pdump Application
7======================
8
9The ``dpdk-pdump`` tool is a Data Plane Development Kit (DPDK) tool that runs as
10a DPDK secondary process and is capable of enabling packet capture on dpdk ports.
11
12   .. Note::
13      * The ``dpdk-pdump`` tool can only be used in conjunction with a primary
14        application which has the packet capture framework initialized already.
15        In dpdk, only the ``testpmd`` is modified to initialize packet capture
16        framework, other applications remain untouched. So, if the ``dpdk-pdump``
17        tool has to be used with any application other than the testpmd, user
18        needs to explicitly modify that application to call packet capture
19        framework initialization code. Refer ``app/test-pmd/testpmd.c``
20        code to see how this is done.
21
22      * The ``dpdk-pdump`` tool depends on libpcap based PMD which is disabled
23        by default in the build configuration files,
24        owing to an external dependency on the libpcap development files
25        which must be installed on the board.
26        Once the libpcap development files are installed, the libpcap based PMD
27        can be enabled by setting CONFIG_RTE_LIBRTE_PMD_PCAP=y and recompiling the DPDK.
28
29      * The ``dpdk-pdump`` tool runs as a DPDK secondary process. It exits when
30        the primary application exits.
31
32
33Running the Application
34-----------------------
35
36The tool has a number of command line options:
37
38.. code-block:: console
39
40   ./build/app/dpdk-pdump --
41                          [--multi]
42                          --pdump '(port=<port id> | device_id=<pci id or vdev name>),
43                                   (queue=<queue_id>),
44                                   (rx-dev=<iface or pcap file> |
45                                    tx-dev=<iface or pcap file>),
46                                   [ring-size=<ring size>],
47                                   [mbuf-size=<mbuf data size>],
48                                   [total-num-mbufs=<number of mbufs>]'
49
50The ``--multi`` command line option is optional argument. If passed, capture
51will be running on unique cores for all ``--pdump`` options. If ignored,
52capture will be running on single core for all ``--pdump`` options.
53
54The ``--pdump`` command line option is mandatory and it takes various sub arguments which are described in
55below section.
56
57   .. Note::
58
59      * Parameters inside the parentheses represents mandatory parameters.
60
61      * Parameters inside the square brackets represents optional parameters.
62
63      * Multiple instances of ``--pdump`` can be passed to capture packets on different port and queue combinations.
64
65
66The ``--pdump`` parameters
67~~~~~~~~~~~~~~~~~~~~~~~~~~
68
69``port``:
70Port id of the eth device on which packets should be captured.
71
72``device_id``:
73PCI address (or) name of the eth device on which packets should be captured.
74
75   .. Note::
76
77      * As of now the ``dpdk-pdump`` tool cannot capture the packets of virtual devices
78        in the primary process due to a bug in the ethdev library. Due to this bug, in a multi process context,
79        when the primary and secondary have different ports set, then the secondary process
80        (here the ``dpdk-pdump`` tool) overwrites the ``rte_eth_devices[]`` entries of the primary process.
81
82``queue``:
83Queue id of the eth device on which packets should be captured. The user can pass a queue value of ``*`` to enable
84packet capture on all queues of the eth device.
85
86``rx-dev``:
87Can be either a pcap file name or any Linux iface.
88
89``tx-dev``:
90Can be either a pcap file name or any Linux iface.
91
92   .. Note::
93
94      * To receive ingress packets only, ``rx-dev`` should be passed.
95
96      * To receive egress packets only, ``tx-dev`` should be passed.
97
98      * To receive ingress and egress packets separately ``rx-dev`` and ``tx-dev``
99        should both be passed with the different file names or the Linux iface names.
100
101      * To receive ingress and egress packets together, ``rx-dev`` and ``tx-dev``
102        should both be passed with the same file name or the same Linux iface name.
103
104``ring-size``:
105Size of the ring. This value is used internally for ring creation. The ring will be used to enqueue the packets from
106the primary application to the secondary. This is an optional parameter with default size 16384.
107
108``mbuf-size``:
109Size of the mbuf data. This is used internally for mempool creation. Ideally this value must be same as
110the primary application's mempool's mbuf data size which is used for packet RX. This is an optional parameter with
111default size 2176.
112
113``total-num-mbufs``:
114Total number mbufs in mempool. This is used internally for mempool creation. This is an optional parameter with default
115value 65535.
116
117
118Example
119-------
120
121.. code-block:: console
122
123   $ sudo ./build/app/dpdk-pdump -l 3 -- --pdump 'port=0,queue=*,rx-dev=/tmp/rx.pcap'
124   $ sudo ./build/app/dpdk-pdump -l 3,4,5 -- --multi --pdump 'port=0,queue=*,rx-dev=/tmp/rx-1.pcap' --pdump 'port=1,queue=*,rx-dev=/tmp/rx-2.pcap'
125