Deploying Example eBPF Programs On Local Host

This section describes running bpfman and the example eBPF programs on a local host.

Example Overview

Assume the following command is run:

cd bpfman/examples/go-xdp-counter/
sudo ./go-xdp-counter -iface eno3

The diagram below shows go-xdp-counter example, but the other examples operate in a similar fashion.

go-xdp-counter On Host

Following the diagram (Purple numbers):

When go-xdp-counter userspace is started, it will send a gRPC request over unix socket to bpfman-rpc requesting bpfman to load the go-xdp-counter eBPF bytecode located on disk at bpfman/examples/go-xdp-counter/bpf_bpfel.o at a priority of 50 and on interface eno3. These values are configurable as we will see later, but for now we will use the defaults (except interface, which is required to be entered).
bpfman will load it's dispatcher eBPF program, which links to the go-xdp-counter eBPF program and return a kernel Program ID referencing the running program.
bpfman list can be used to show that the eBPF program was loaded.
Once the go-xdp-counter eBPF bytecode is loaded, the eBPF program will write packet counts and byte counts to a shared map.
go-xdp-counter userspace program periodically reads counters from the shared map and logs the value.

Below are the steps to run the example program described above and then some additional examples that use the bpfman CLI to load and unload other eBPF programs. See Launching bpfman for more detailed instructions on building and loading bpfman. This tutorial assumes bpfman has been built, bpfman-rpc is running, and the bpfman CLI is in $PATH.

Running Example Programs

Example eBPF Programs describes how the example programs work, how to build them, and how to run the different examples. Build the go-xdp-counter program before continuing.

To run the go-xdp-counter program, determine the host interface to attach the eBPF program to and then start the go program. In this example, eno3 will be used, as shown in the diagram at the top of the page. The output should show the count and total bytes of packets as they pass through the interface as shown below:

sudo ./go-xdp-counter --iface eno3
2023/07/17 17:43:58 Using Input: Interface=eno3 Priority=50 Source=/home/<$USER>/src/bpfman/examples/go-xdp-counter/bpf_bpfel.o
2023/07/17 17:43:58 Program registered with id 6211
2023/07/17 17:44:01 4 packets received
2023/07/17 17:44:01 580 bytes received

2023/07/17 17:44:04 4 packets received
2023/07/17 17:44:04 580 bytes received

2023/07/17 17:44:07 8 packets received
2023/07/17 17:44:07 1160 bytes received

:

In another terminal, use the CLI to show the go-xdp-counter eBPF bytecode was loaded.

sudo bpfman list
 Program ID  Name       Type  Load Time
 6211        xdp_stats  xdp   2023-07-17T17:43:58-0400

Finally, press <CTRL>+c when finished with go-xdp-counter.

:

2023/07/17 17:44:34 28 packets received
2023/07/17 17:44:34 4060 bytes received

^C2023/07/17 17:44:35 Exiting...
2023/07/17 17:44:35 Unloading Program: 6211

Using CLI to Manage eBPF Programs

bpfman provides a CLI to interact with the bpfman Library. Find a deeper dive into CLI syntax in CLI Guide. We will load the simple xdp-pass program, which allows all traffic to pass through the attached interface, eno3 in this example. The source code, xdp_pass.bpf.c, is located in the integration-test directory and there is also a prebuilt image: quay.io/bpfman-bytecode/xdp_pass:latest.

sudo bpfman load image --image-url quay.io/bpfman-bytecode/xdp_pass:latest xdp --iface eno3 --priority 100
 Bpfman State
---------------
 Name:          pass
 Image URL:     quay.io/bpfman-bytecode/xdp_pass:latest
 Pull Policy:   IfNotPresent
 Global:        None
 Metadata:      None
 Map Pin Path:  /run/bpfman/fs/maps/6213
 Map Owner ID:  None
 Map Used By:   6213
 Priority:      100
 Iface:         eno3
 Position:      0
 Proceed On:    pass, dispatcher_return

 Kernel State
----------------------------------
 Program ID:                       6213
 Name:                             pass
 Type:                             xdp
 Loaded At:                        2023-07-17T17:48:10-0400
 Tag:                              4b9d1b2c140e87ce
 GPL Compatible:                   true
 Map IDs:                          [2724]
 BTF ID:                           2834
 Size Translated (bytes):          96
 JITed:                            true
 Size JITed (bytes):               67
 Kernel Allocated Memory (bytes):  4096
 Verified Instruction Count:       9

bpfman load image returns the same data as the bpfman get command. From the output, the Program Id of 6213 can be found in the Kernel State section. The Program Id can be used to perform a bpfman get to retrieve all relevant program data and a bpfman unload when the program needs to be unloaded.

sudo bpfman list
 Program ID  Name  Type  Load Time
 6213        pass  xdp   2023-07-17T17:48:10-0400

We can recheck the details about the loaded program with the bpfman get command:

sudo bpfman get 6213
 Bpfman State
---------------
 Name:          pass
 Image URL:     quay.io/bpfman-bytecode/xdp_pass:latest
 Pull Policy:   IfNotPresent
 Global:        None
 Metadata:      None
 Map Pin Path:  /run/bpfman/fs/maps/6213
 Map Owner ID:  None
 Map Used By:   6213
 Priority:      100
 Iface:         eno3
 Position:      0
 Proceed On:    pass, dispatcher_return

 Kernel State
----------------------------------
 Program ID:                       6213
 Name:                             pass
 Type:                             xdp
 Loaded At:                        2023-07-17T17:48:10-0400
 Tag:                              4b9d1b2c140e87ce
 GPL Compatible:                   true
 Map IDs:                          [2724]
 BTF ID:                           2834
 Size Translated (bytes):          96
 JITed:                            true
 Size JITed (bytes):               67
 Kernel Allocated Memory (bytes):  4096
 Verified Instruction Count:       9

Then unload the program:

sudo bpfman unload 6213