DPDK-Dump

1. Description of the software

This program is able to store on disk network traffic at high speed using Intel DPDK library. It retreives traffic from network interfaces and writes it on disk in pcap format. It can achieve high speed when the disks are fast.

• For information about DPDK please read: http://dpdk.org/doc
• For information about this Readme file and DPDK-Dump please write to martino.trevisan@studenti.polito.it
• DPDK-Dump is part of ongoing related effort to release open-source 10Gbps+ tools useful for the networking community. A larger set of tools is collected at this page: http://www.telecom-paristech.fr/~drossi/index.php?n=Software.10GbpsTools
• DPDK-Dump has been developed in the context of the FP7 mPlane project – an Intelligent Measurement plane for Future Network and Application Management (http://www.ict-mplane.eu/)

2. Requirements

• A machine with DPDK supported network interfaces.
• A Debian based Linux distribution with kernel >= 2.6.3
• Linux kernel headers: to install type

	sudo apt-get install linux-headers-$(uname -r)

• Several package needed before installing this software:
  • DPDK needs: make, cmp, sed, grep, arch, glibc.i686, libgcc.i686, libstdc++.i686, glibc-devel.i686, python
  • DPDK-Dump needs: git, libpcap-dev, libpcap

3. Installation

3.1 Install DPDK

Install DPDK 1.8.0. With other versions is not guaranted it works properly. Make the enviroment variable RTE_SDK and RTE_TARGET to point respectively to DPDK installation directory and compilation target. For documentation and details see http://dpdk.org/doc/guides/linux_gsg/index.html

	wget http://dpdk.org/browse/dpdk/snapshot/dpdk-1.8.0.tar.gz
	tar xzf dpdk-1.8.0.tar.gz
	cd dpdk-1.8.0
	export RTE_SDK=$(pwd)
	export RTE_TARGET=x86_64-native-linuxapp-gcc
	make install T=$RTE_TARGET
	cd ..

NOTE: if you are running on a i686 machine, please use i686-native-linuxapp-gcc as RTE_TARGET

3.2 Install DPDK-Dump

Get it from the git repository. Remind to set RTE_SDK and RTE_TARGET.

	git clone https://github.com/marty90/DPDK-Dump
	cd DPDK-Dump
	make
	cd ..

4. Configuration of the machine

Before running DPDK-Dump there are few things to do:

4.1 Reserve a big number of hugepages to DPDK

The commands below reserve 1024 hugepages. The size of each huge page is 2MB. Check to have enough RAM on your machine.

	sudo su
	echo 1024 >/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages
	mkdir -p /mnt/huge
	mount -t hugetlbfs nodev /mnt/huge

4.2 Set CPU on performance governor

To achieve the best performances, your CPU must run always at the highest speed. You need to have installed cpufrequtils package.

	sudo cpufreq-set -r -g performance

4.3 Bind the interfaces you want to use with DPDK drivers

It means that you have to load DPDK driver and associate it to you network interface. DPDK-Dump reads packets from all the interfaces bound to DPDK. Remember to set RTE_SDK and RTE_TARGET when executing the below commands.

	sudo modprobe uio
	sudo insmod $RTE_SDK/$RTE_TARGET/kmod/igb_uio.ko
	sudo $RTE_SDK/tools/dpdk_nic_bind.py --bind=igb_uio $($RTE_SDK/tools/dpdk_nic_bind.py --status | sed -rn 's,.* if=([^ ]*).*igb_uio *$,\1,p')

In this way all the DPDK-supported interfaces are working with DPDK drivers. To check if your network interfaces have been properly set by the Intel DPDK enviroment run:

	sudo $RTE_SDK/tools/dpdk_nic_bind.py --status

You should get an output like this, which means that the first two interfaces are running under DPDK driver, while the third is not:

Network devices using DPDK-compatible driver
============================================
0000:04:00.0 'Ethernet Controller 10-Gigabit X540-AT2' drv=igb_uio unused=
0000:04:00.1 'Ethernet Controller 10-Gigabit X540-AT2' drv=igb_uio unused=
Network devices using kernel driver
===================================
0000:03:00.0 'NetXtreme BCM5719 Gigabit Ethernet PCIe' if=eth0 drv=tg3 unused=igb_uio *Active*

NOTE: If for any reason you don't want to bind all the DPDK-supported interfaces to DPDK enviroment, use the dpdk_nic_bind.py as described in the DPDK getting started guide.

5. Usage

To start DPDK-Dump just execute ./build/dpdk-dump. If not specified it uses all the port bound to DPDK drivers. Root priviledges are needed. The are few parameters:

	./build/dpdk-dump -c COREMASK -n NUM [-w PCI_ADDR] -- -w file [-c num_pkt] [-C max_size] [-G rotate_seconds] [-W num_rotations] [-B buffer_size]

The parameters have this meaning:

• COREMASK: The cores where to bind the program. It needs 2 cores
• NUM: Number of memory channels to use. It's 2 or 4.
• PCI_ADDR: The port(s) where to capture. If not present, it captures from every port.
• file: output file in pcap format
• num_pkt: quit after saving num_pkt packets
• max_size: quit after saving an amount of packets equal to max_size (in KB).
• rotate_seconds: rotate dump files each rotate_seconds. Progressive numbers edded to file name.
• num_rotations: maximum number of rotations to do. If 0 it quits after rotate_seconds.
• buffer_size: Internal buffer size. Default is 1 Milion packets.

The parameters before -- are DPDK enviroment related. See its guide for further explaination.

Here some example of command lines:

• It starts a capture unbounded in time to the file capture.pcap

	sudo ./build/dpdk-dump -c 0x03 -n 4 -- -w capture.pcap

• It starts a capture changing capture file every 60 seconds. After 30 files (30 minutes) it quits.

	sudo ./build/dpdk-dump -c 0x03 -n 4 -- -w capture.pcap -G 60 -w 30

• It starts a capture just on the device with the specified PCI address. -w is a parameter of DPDK enviroment.

	sudo ./build/dpdk-dump -c 0x03 -n 4 -w 01:00.0 -- -w capture.pcap

The system approximately each one seconds prints statistics about its performances, a line each port.

PORT:  0 Rx: 102669 Drp: 0 Tot: 102669 Perc: 0.000%
PORT:  1 Rx: 88060  Drp: 0 Tot: 88060  Perc: 0.000%
-------------------------------------------------
TOT:     Rx: 190729 Drp: 0 Tot: 190729 Perc: 0.000%