DPDK-P4 Buffer Overflow Management

Table of Contents

• Introduction
• Methods
• Installation
• License

Introduction

This project involved the design and implementation of a software switch using DPDK (Data Plane Development Kit) that is configurable with P4 (Programming Protocol-Independent Packet Processors).

Methods

Our Integrated solution is comprised of two main stages:

A packet classifier that can be configured in real-time. The classifier is being loaded to the system in real-time using P4. The classifier assigns a Quality of Service (QoS) value to each packet.

Buffer-overflow management algorithm, Implemented in the NIC’s DPDK driver (depends on the free buffer space and the packet’s QoS). Default algorithm – Every packet passes. Three Buffers Round Robin – The buffer is split into three sub-buffers for handling packets with different priorities, and each sub-buffer is served in a round-robin manner. Inverse Linear algorithm – Packets pass \ dropped deterministically (QoS threshold). Probabilistic Algorithm – Packets are passes \ dropped based on a probability model:

Results

We collected data of the total QoS passed through the switch and performed a competitive analysis of the different algorithms. From our results we obtained, we observe a clear improvement of the default packet forwarding procedure in a high-stress network state. Also, The switch can support different communication protocols, which can be configured in real-time

Installation

1. clone

git clone https://github.com/guy-davidi/p4_project

2. run installtion scripts

chmod 755 ./scripts/p4cinstall.sh
./scripts/p4c_install.sh
chmod 755 ./scripts/dpdk_install.sh
./scripts/dpdk_install.sh

3. Build DPDK's Pipeline APP

mkdir build
make

4. DPDK's uses NICs, Bind DPDK driver to device

cd /home/user/dpdk/usertools
sudo ./dpdk-devbind.py -b vfio-pci 0000:01:00.0
sudo ./dpdk-devbind.py -b vfio-pci 0000:05:00.0

5. Compilation l2fwd.P4 -> l2fwd.spec (which DPDK's pipeline uses)

p4c-dpdk --arch psa l2fwd.p4 -o l2fwd.spec 

6. In order run l2fwd (example)

sudo su
cd  ~/p4_project
sudo ./dpdk-pipeline -c 0x3 -- -s l2fwd.cli

7. Connecting CLI DPDK-Pipeline APP

telnet 0.0.0.0 8086
pipeline PIPELINE0 stats

8. In order to add table entries last must be call to 'commit' Note that Class Of Service is given to a packet in addition to egress port.

pipeline PIPELINE0 stats
pipeline PIPELINE0 table ipv4_host add ipv4_host_table.txt
pipeline PIPELINE0 commit
pipeline PIPELINE0 table ipv4_host show
Table ipv4_host: key size 4 bytes, key offset 16, key mask [ffffffff], action data size 4 bytes
match 0x0A000000 action send port 0x1 class 1
match 0x0B652B58 action send port 0x0 class 2
Table ipv4_host currently has 2 entries.

9. Showing the stats of the pipeline - output

Input ports:
        Port 0: packets 877005976 bytes 52620358560 empty 14523130228
        Port 1: packets 625173214 bytes 37510392840 empty 14774963007

Output ports:
        Port 0: packets 0 bytes 0 clone 0 clonerr 0
        Port 1: packets 48986172 bytes 2939170320 clone 0 clonerr 0
        DROP: packets 1453193035 bytes 66846879610 clone 0 clonerr 0

Tables:
        Table ipv4_host:
                Hit (packets): 48986184
                Miss (packets): 1453193035
                Action NoAction (packets): 1453193035
                Action send (packets): 48986184
                Action drop_1 (packets): 0

10. Read QoS from DPDK-App CLI

pipeline PIPELINE0 regrd reg_counter_0 0

11. Run worker process:

cd worker
gcc worker.c -o worker
./worker

12. Run Traffic from Ixia by ixexplorer Ixia application.

It can be seen that each sample has exact jump of 5 packets with QoS -> "17" that gave in the match action table!

Wrtting QoS to hdr.ipv4.src_addr = class

License

MIT License