XDP test harness

A test harness that can be used to test the implementation of XDP and XDP programs.

Requirements

Python 3.5, bcc, Pyroute2, Scapy

Usage

Running

To start the test harness, run python3 -m xdp_test_harness.runner in a folder containing tests as a superuser. There are three commands that can be used:

client

Start a client, running tests using network interfaces to process packets by XDP program. One can further specify which tests to run, using unittest's format. That is modules, classes and methods separated by dots, for example python3 -m xdp_test_harness.runner client test_general.ReturnValuesBasic.

bptr

Similar to the client command, but uses the BPF_PROG_TEST_RUN syscall command instead of a server to process packets by an XDP program.

server

Starts a server, used by client command to send packets.

Configuration

Configuration of interfaces to be used for testing is done in the config.py file. In the configuration file there are two variables:

local_server_ctx

A variable specifying the interface of the server, used for testing, and the interface of the server used for communication with a client.

local_server_ctx = ContextServer(
    ContextLocal("enp0s31f6"),
    ContextCommunication("192.168.0.106", 6555),
)

remote_server_ctxs

List of contexts specifying one physical testing interface and one virtual testing interface. Elements of the list are either ContextClient objects, for physical interfaces, or objects created by new_virtual_ctx function, for virtual interfaces.

remote_server_ctxs = ContextClientList([
    ContextClient(
        ContextLocal("enp0s31f6", xdp_mode=XDPFlag.SKB_MODE),
        ContextCommunication("192.168.0.107", 6555)
    ),
    new_virtual_ctx(
        ContextLocal("a_to_b", xdp_mode=XDPFlag.DRV_MODE),
        ContextCommunication("192.168.1.1"),
        "test_b",
        ContextLocal("b_to_a", xdp_mode=XDPFlag.DRV_MODE),
        ContextCommunication("192.168.1.2", 6000),
    ),
])

Creating new tests

To create a new test, create a class inheriting from XDPCase. This class should be located in a file named with a test_ prefix and placed in the tests folder. Each method of this class, that should be run while testing, has to be named with a test_ prefix.

Each test should either call both load_bpf and attach_xdp methods in this order, before calling send_packets, or be decorated with usingCustomLoader and attach own XDP program to the interface. After attaching attaching an XDP program, calling send_packets, returns a SendResult object, containing lists of packets that arrived to each interface engaged in testing.