NAME

       dpdk-pdump - enable packet capture on dpdk ports

       The  dpdk-pdump  tool  is  a  Data  Plane  Development Kit (DPDK) tool that runs as a DPDK
       secondary process and is capable of enabling packet capture on dpdk ports.

          NOTE:

              • The dpdk-pdump tool can only be used in conjunction with  a  primary  application
                which  has  the  packet capture framework initialized already.  In dpdk, only the
                testpmd is modified to initialize packet capture  framework,  other  applications
                remain  untouched. So, if the dpdk-pdump tool has to be used with any application
                other than the testpmd, user needs to explicitly modify that application to  call
                packet  capture  framework initialization code. Refer app/test-pmd/testpmd.c code
                to see how this is done.

              • The dpdk-pdump tool depends on libpcap based PMD which is disabled by default  in
                the  build  configuration  files,  owing to an external dependency on the libpcap
                development files which must  be  installed  on  the  board.   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.

RUNNING THE APPLICATION

       The tool has a number of command line options:

          ./build/app/dpdk-pdump --
                                 --pdump '(port=<port id> | device_id=<pci id or vdev name>),
                                          (queue=<queue_id>),
                                          (rx-dev=<iface or pcap file> |
                                           tx-dev=<iface or pcap file>),
                                          [ring-size=<ring size>],
                                          [mbuf-size=<mbuf data size>],
                                          [total-num-mbufs=<number of mbufs>]'
                                 [--server-socket-path=<server socket dir>]
                                 [--client-socket-path=<client socket dir>]

       The --pdump command line option is mandatory and it takes various sub arguments which  are
       described in below section.

          NOTE:

              • Parameters inside the parentheses represents mandatory parameters.

              • Parameters inside the square brackets represents optional parameters.

              • Multiple  instances of --pdump can be passed to capture packets on different port
                and queue combinations.

       The --server-socket-path command line option  is  optional.  This  represents  the  server
       socket  directory.  If no value is passed default values are used i.e. /var/run/.dpdk/ for
       root users and ~/.dpdk/ for non root users.

       The --client-socket-path command line option  is  optional.  This  represents  the  client
       socket  directory.  If no value is passed default values are used i.e. /var/run/.dpdk/ for
       root users and ~/.dpdk/ for non root users.

   The --pdump parameters
       port: Port id of the eth device on which packets should be captured.

       device_id: PCI address (or) name of the eth device on which packets should be captured.

          NOTE:

              • As of now the dpdk-pdump tool cannot capture the packets of  virtual  devices  in
                the  primary  process  due  to a bug in the ethdev library. Due to this bug, in a
                multi process context, when the primary and secondary have different  ports  set,
                then   the   secondary   process   (here  the  dpdk-pdump  tool)  overwrites  the
                rte_eth_devices[] entries of the primary process.

       queue: Queue id of the eth device on which packets should be captured. The user can pass a
       queue value of * to enable packet capture on all queues of the eth device.

       rx-dev: Can be either a pcap file name or any Linux iface.

       tx-dev: Can be either a pcap file name or any Linux iface.

          NOTE:

              • To receive ingress packets only, rx-dev should be passed.

              • To receive egress packets only, tx-dev should be passed.

              • To receive ingress and egress packets separately rx-dev and tx-dev should both be
                passed with the different file names or the Linux iface names.

              • To receive ingress and egress packets together, rx-dev and tx-dev should both  be
                passed with the same file name or the same Linux iface name.

       ring-size:  Size  of  the  ring. This value is used internally for ring creation. The ring
       will be used to enqueue the packets from the primary application to the secondary. This is
       an optional parameter with default size 16384.

       mbuf-size:  Size  of  the mbuf data. This is used internally for mempool creation. Ideally
       this value must be same as the primary application's mempool's mbuf  data  size  which  is
       used for packet RX. This is an optional parameter with default size 2176.

       total-num-mbufs:  Total  number  mbufs  in  mempool.  This  is used internally for mempool
       creation. This is an optional parameter with default value 65535.

EXAMPLE

          $ sudo ./build/app/dpdk-pdump -- --pdump 'port=0,queue=*,rx-dev=/tmp/rx.pcap'