Re: [PATCH v3 2/2] selftests/bpf: integrate test_xdp_veth into test_progs

[Daniel Borkmann <daniel@xxxxxxxxxxxxx>]

On 7/16/24 12:13 PM, Alexis Lothoré (eBPF Foundation) wrote:
[...]
> +static int attach_programs_to_veth_pair(struct skeletons *skeletons, int index)
> +{
> +	struct bpf_program *local_prog, *remote_prog;
> +	struct bpf_link **local_link, **remote_link;
> +	struct nstoken *nstoken;
> +	struct bpf_link *link;
> +	int interface;
> +
> +	switch (index) {
> +	case 0:
> +		local_prog = skeletons->xdp_redirect_maps->progs.xdp_redirect_map_0;
> +		local_link = &skeletons->xdp_redirect_maps->links.xdp_redirect_map_0;
> +		remote_prog = skeletons->xdp_dummy->progs.xdp_dummy_prog;
> +		remote_link = &skeletons->xdp_dummy->links.xdp_dummy_prog;
> +		break;
> +	case 1:
> +		local_prog = skeletons->xdp_redirect_maps->progs.xdp_redirect_map_1;
> +		local_link = &skeletons->xdp_redirect_maps->links.xdp_redirect_map_1;
> +		remote_prog = skeletons->xdp_tx->progs.xdp_tx;
> +		remote_link = &skeletons->xdp_tx->links.xdp_tx;
> +		break;
> +	case 2:
> +		local_prog = skeletons->xdp_redirect_maps->progs.xdp_redirect_map_2;
> +		local_link = &skeletons->xdp_redirect_maps->links.xdp_redirect_map_2;
> +		remote_prog = skeletons->xdp_dummy->progs.xdp_dummy_prog;
> +		remote_link = &skeletons->xdp_dummy->links.xdp_dummy_prog;
> +		break;
> +	}
> +	interface = if_nametoindex(config[index].local_veth);
> +	if (!ASSERT_NEQ(interface, 0, "non zero interface index"))
> +		return -1;
> +	link = bpf_program__attach_xdp(local_prog, interface);
> +	if (!ASSERT_OK_PTR(link, "attach xdp program to local veth"))
> +		return -1;
> +	*local_link = link;
> +	nstoken = open_netns(config[index].namespace);
> +	if (!ASSERT_OK_PTR(nstoken, "switch to remote veth namespace"))
> +		return -1;
> +	interface = if_nametoindex(config[index].remote_veth);
> +	if (!ASSERT_NEQ(interface, 0, "non zero interface index"))
> +		return -1;

Missing `close_netns(nstoken);` in error path here, otherwise looks reasonable to me.

> +	link = bpf_program__attach_xdp(remote_prog, interface);
> +	*remote_link = link;
> +	close_netns(nstoken);
> +	if (!ASSERT_OK_PTR(link, "attach xdp program to remote veth"))
> +		return -1;
> +
> +	return 0;
> +}

Thanks,
Daniel