crain-cn/ebpf-network-emulation

ebpf-network-emulation

This repository contains experimental code for a network emulation tool based on eBPF as well as experiment artifacts for it. We also include experiment setups and results to test NetEm.

Research

If you use this software in a publication, please cite it as:

Text

S. Becker, T. Pfandzelter, N. Japke, D. Bermbach, O. Kao, Network Emulation in Large-Scale Virtual Edge Testbeds: A Note of Caution and the Way Forward, Proceedings of the 2nd International Workshop on Testing Distributed Internet of Things Systems (TDIS 2022), Pacific Grove, CA, USA, 2022.

BibTeX

@inproceedings{becker_netem_ebpf:_2022,
    title = "Network Emulation in Large-Scale Virtual Edge Testbeds: A Note of Caution and the Way Forward",
    booktitle = "Proceedings of the 2nd International Workshop on Testing Distributed Internet of Things Systems (TDIS 2022)",
    author = "Becker, Soeren and Pfandzelter, Tobias Pfandzelter and Japke, Nils and Bermbach, David and Kao, Odej",
    year = 2022
}

For a full list of publications, please see our website.

License

A license for the code in this repository is pending.

Dependencies

The following installs the needed dependencies on Ubuntu 20.04 / 22.04:

sudo apt-get install -y clang gcc-multilib libbpf-dev

Compilation

Use the provided Makefile, the eBPF programs will be compiled with go generate:

make all

The binaries can be found in the bin dir.

Examples

da-example

Simple example showcasing the direct-action flag of tc.

ebpf-delay

Set different delays per IP destination based on a shared eBPF map and a single fq qdisc.

Usage

sudo ./bin/ebpf-delay -iface eth0

ebpf-network-simulation

Limit the available bandwidth to different IP destinations using the Earliest Departure Time model and set a delay, based on a shared eBPF map.

Usage

sudo ./bin/ebpf-network-simulation -iface eth0

map-populator

Populate an eBPF map with a given number of entries. The map has the following structure and is utilized by ebpf-delay and edt-bandwidth-limit:

struct handle_bps_delay {
    __u32 tc_handle;          // TC handle, used for classic htb qdisc version
    __u32 throttle_rate_bps;  // Throttled bandwidth (in BPS)
    __u32 delay_ms;           // Delay in ms
} HANDLE_BPS_DELAY;

struct {
    __uint(type, BPF_MAP_TYPE_HASH);
    __type(key, __u32);              // The IP destination
    __type(value, HANDLE_BPS_DELAY);
    __uint(pinning, LIBBPF_PIN_BY_NAME); 
    __uint(max_entries, 65535);
} IP_HANDLE_BPS_DELAY SEC(".maps");

The map declaration can be found here.

Usage

First run either ebpf-delay or ebpf-network-simulation.

sudo ./bin/map-populator

Remove

sudo tc qdisc del dev eth0 clsact
sudo tc qdisc del dev eth0 root
sudo rm /sys/fs/bpf/IP_HANDLE_BPS_DELAY
sudo rm /sys/fs/bpf/progs

Used Resources

njapke/ebpf-ip-classifier

njapke/ebpf-map-populator

njapke/tc-qdisc-test

Replacing HTB with EDT and BPF