Re: [PATCH 2/3] selftests/bpf: Migrate test_xdp_redirect.sh to xdp_do_redirect.c

[Alexis Lothoré]

Hi Bastien,

On 1/3/25 11:10, Bastien Curutchet (eBPF Foundation) wrote:

[...]

> +		SYS(fail, "ip link add veth%d index %d%d%d type veth peer name veth0 netns %s",
> +		    i, i, i, i, ns_name);

nit: since you have to run an ip command through SYS anyway, you can reduce the
open ns/run command/close ns dance (and all the resulting error checks) by
running directly `SYS("ip netns exec %s ip link add [...]", NS0, [...])`

[...]

> +	ret = bpf_xdp_attach(if_nametoindex("veth2"),
> +			     bpf_program__fd(prog_to_111),
> +			     data->xdp_flags, NULL);

nit: since we are setting static if index at veth creation (which looks needed
for this test), the if_nametoindex could be replaced by the corresponding index,
which could be directly a define

> +	if (!ASSERT_GE(ret, 0, "bpf_xdp_attach"))
> +		goto close;
> +
> +	ret = bpf_xdp_attach(if_nametoindex("veth1"),
> +			     bpf_program__fd(prog_to_222),
> +			     data->xdp_flags, NULL);
> +	if (!ASSERT_GE(ret, 0, "bpf_xdp_attach"))
> +		goto close;
> +
> +	close_netns(nstoken);
> +
> +	nstoken = open_netns(NS1);
> +	if (!ASSERT_OK_PTR(nstoken, "open NS1"))
> +		goto close;
> +
> +	SYS(close, "ping -c 1 %s.2", IPV4_NETWORK);
> +
> +	close_netns(nstoken);
> +
> +	nstoken = open_netns(NS2);
> +	if (!ASSERT_OK_PTR(nstoken, "open NS2"))
> +		goto close;
> +
> +	SYS(close, "ping -c 1 %s.1", IPV4_NETWORK);

Is it really useful to check ping originating from both interfaces, isn´t a
single ping able to stimulate programs attached to both veth0 ?

Aside from those minor points, LGTM :)

-- 
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com