Go Packet Generator (go-pktgen)

For more information, also see my blog here: High-Speed Packet Transmission in Go: From net.Dial to AF_XDP

The Go Packet Generator (go-pktgen) is a tool designed for network performance testing and stress testing. It demonstrates various methods of generating and sending packets in Go, allowing users to compare the performance differences between these methods. This tool supports direct AF_PACKET access, AF_XDP, raw sockets, high-level abstractions like net.Conn, and more.

Goal

The primary goal of go-pktgen is to showcase different packet generation techniques in Go and to facilitate performance comparisons among these methods under various conditions. Below is an example benchmark result comparing the performance of different packet-sending methods:

./go-pktgen --dstip 192.168.64.2 --method benchmark --duration 5 --payloadsize 64 --iface veth0
+-------------+-----------+------+
|   Method    | Packets/s | Mb/s |
+-------------+-----------+------+
| af_xdp      |   2620595 | 1341 |
| af_packet   |   1159690 |  593 |
| af_pcap     |   1037554 |  531 |
| udp_syscall |    688522 |  352 |
| raw_socket  |    643401 |  329 |
| pkt_conn    |    606258 |  310 |
| net_conn    |    354065 |  181 |
+-------------+-----------+------+

The above was tested on an AMD EPYC 9124 @ 3.71GHz (16 cores)

Getting Started

Prerequisites

This tool is designed to run on Linux. Running on other platforms will not work for certain packet sending methods like AF_PACKET and AF_XDP. you need libpcap-dev and build-essential sudo apt-get install build-essential libpcap-dev

Compilation

Note this tool for now only works on Linux. To compile the tool, navigate to the root of the repository and run:

go build -o go-pktgen main.go

This command compiles the source code into an executable named go-pktgen.

Usage

To run the packet generator, you can use the following command:

./go-pktgen -h
A versatile packet generation tool designed for network performance and stress testing.

Usage:
  pktgen [flags]

Flags:
      --dstip string      Destination IP address (default "192.168.64.2")
      --dstmac string     Destination MAC address (default "c0:ff:ee:00:00:00")
      --dstport int       Destination UDP port (default 12345)
      --duration int      Duration of the benchmark in seconds (default 5)
  -h, --help              help for pktgen
      --iface string      Interface to use (default "eth0")
      --method string     method to use for sending packets [af_packet, net_conn, udp_syscall, raw_socket, af_pcap, benchmark] (default "af_packet")
      --payloadsize int   Size of the payload in bytes (default 100)
      --srcip string      Source IP address (default "192.168.64.1")
      --srcmac string     Source MAC address (default "de:ad:be:ef:ca:fe")
      --srcport int       Source UDP port (default 12345)
      --streams int       Number of concurrent streams for sending packets (default 1)

Note that pktgen requires root privileges to run, as it needs to access raw sockets and network interfaces. It also checks that the number of streams is less than or equal to the number of available TX queues on the specified interface.

example packet generator sending UDP packets using af_packet

./go-pktgen --dstip 192.168.64.2 --method af_packet --duration 5 --payloadsize 1200 --streams 1  --iface veth0

packet generator sending UDP packets using af_xdp

./go-pktgen --dstip 192.168.64.2 --method af_xdp --duration 5 --payloadsize 1200 --streams 1  --iface veth0

Benchmarking

To compare the performance of different packet sending methods, use the benchmark method:

./go-pktgen --dstip 192.168.64.2 --method benchmark --duration 5 --payloadsize 64 --streams 1 --iface veth0

This will run a series of tests using all available methods and print the results in terms of packets per second and Mbps.

Multiple streams

To use multiple streams, you need to have multiple TX queues. You can check the number of TX queues on your system like this:

ethtool -l veth0
Channel parameters for veth0:
Pre-set maximums:
RX:		16
TX:		16
Other:		n/a
Combined:	n/a
Current hardware settings:
RX:		1
TX:		10
Other:		n/a
Combined:	n/a

Take note of the Current hardware settings for the TX queue. You can change it like this to the maximum, in this example 16

ethtool -L veth0 tx 16

Contributing

Contributions are welcome! Please feel free to submit pull requests, report bugs, or suggest new features.