Files
Frey Alfredsson 9337d2ff8a Adding a basic TC eBPF Qdisc classifier example
This example demonstrates how to write a simple eBPF Qdisc classifier
that classifies flows depending on their destination TCP port. The
example script, runner.sh shows how you can use the eBPF Qdisc
classifier and implement the same functionality using u32. The script
creates two network namespaces called Left and Right, representing two
different hosts. The script then illustrates the classifiers in action
using iperf3 by starting clients on the Left namespace that connect to
iperf3 servers on the Right namespace. The Qdisc classifiers give TCP
ports 8080 and 8081 a high rate limit, while TCP port 8082 represents
all other traffic capped at 20 Mbps.

Signed-off-by: Frey Alfredsson <freysteinn@freysteinn.com>
2021-03-17 02:26:58 +01:00
..

eBPF Qdisc classifier example

This example demonstrates how to write a simple eBPF Qdisc classifier that classifies flows depending on their destination TCP port. The example script, runner.sh shows how you can use the eBPF Qdisc classifier and implement the same functionality using u32. The script creates two network namespaces called Left and Right, representing two different hosts, as seen in Figure 1. The script then illustrates the classifiers in action using iperf3.

./overview.png

The Left namespace loads a Qdisc classifier that rate-limit TCP ports 8080 and 8082 to get a higher rate than default traffic. The runner.sh script shows the higher rate limits by connecting to both target ports and TCP port 8082 to establish the default rate limit of 20 Mbps.

To run the application, choose either the "bpf" or "u32" parameters:

[root@bpfexamples]# ./runner.sh bpf
bash-5.0# ./runner.sh bpf
Starting setup
Starting iperf3
Connecting to host 172.16.16.20, port 8080
[  5] local 172.16.16.10 port 56332 connected to 172.16.16.20 port 8080
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  9.51 MBytes  79.8 Mbits/sec    0   86.3 KBytes
[  5]   1.00-2.00   sec  9.38 MBytes  78.7 Mbits/sec    0    112 KBytes
[  5]   2.00-3.00   sec  8.95 MBytes  75.1 Mbits/sec    0    112 KBytes
[  5]   3.00-4.00   sec  9.20 MBytes  77.2 Mbits/sec    0    112 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-4.00   sec  37.0 MBytes  77.7 Mbits/sec    0             sender
[  5]   0.00-4.01   sec  36.5 MBytes  76.4 Mbits/sec                  receiver

iperf Done.
Connecting to host 172.16.16.20, port 8081
[  5] local 172.16.16.10 port 45084 connected to 172.16.16.20 port 8081
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  4.92 MBytes  41.3 Mbits/sec    0   62.2 KBytes
[  5]   1.00-2.00   sec  4.47 MBytes  37.5 Mbits/sec    0   62.2 KBytes
[  5]   2.00-3.00   sec  4.66 MBytes  39.1 Mbits/sec    0   62.2 KBytes
[  5]   3.00-4.00   sec  4.47 MBytes  37.5 Mbits/sec    0   62.2 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-4.00   sec  18.5 MBytes  38.9 Mbits/sec    0             sender
[  5]   0.00-4.01   sec  18.3 MBytes  38.2 Mbits/sec                  receiver

iperf Done.
Connecting to host 172.16.16.20, port 8082
[  5] local 172.16.16.10 port 33196 connected to 172.16.16.20 port 8082
[ ID] Interval           Transfer     Bitrate         Retr  Cwnd
[  5]   0.00-1.00   sec  2.94 MBytes  24.6 Mbits/sec    0    153 KBytes
[  5]   1.00-2.00   sec  2.49 MBytes  20.9 Mbits/sec    0    153 KBytes
[  5]   2.00-3.00   sec  2.17 MBytes  18.2 Mbits/sec    0    153 KBytes
[  5]   3.00-4.00   sec  2.17 MBytes  18.2 Mbits/sec    0    153 KBytes
- - - - - - - - - - - - - - - - - - - - - - - - -
[ ID] Interval           Transfer     Bitrate         Retr
[  5]   0.00-4.00   sec  9.77 MBytes  20.5 Mbits/sec    0             sender
[  5]   0.00-4.01   sec  9.14 MBytes  19.1 Mbits/sec                  receiver

iperf Done.
[root@bpfexamples]# ./runner.sh bpf