Re: [PATCH bpf-next] selftests/bpf: Use make/remove netns helpers in mptcp

[Martin KaFai Lau <martin.lau@linux.dev>]

On 10/24/24 1:11 AM, Geliang Tang wrote:
> From: Geliang Tang <tanggeliang@kylinos.cn>
> 
> New netns selftest helpers make_netns() and remove_netns() has been added
> in network_helpers.c, let's use them in mptcp selftests too.
> 
> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
> ---
>   tools/testing/selftests/bpf/prog_tests/mptcp.c | 18 ++++++++++++------
>   1 file changed, 12 insertions(+), 6 deletions(-)
> 
> diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> index d2ca32fa3b21..8276398f7d6a 100644
> --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
> +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> @@ -66,12 +66,18 @@ struct mptcp_storage {
>   
>   static struct nstoken *create_netns(void)
>   {
> -	SYS(fail, "ip netns add %s", NS_TEST);
> -	SYS(fail, "ip -net %s link set dev lo up", NS_TEST);
> +	struct nstoken *nstoken;
>   
> -	return open_netns(NS_TEST);
> -fail:
> -	return NULL;
> +	if (make_netns(NS_TEST) < 0)
> +		return NULL;
> +
> +	nstoken = open_netns(NS_TEST);
> +	if (!nstoken) {
> +		log_err("open netns %s failed", NS_TEST);
> +		remove_netns(NS_TEST);
> +	}
> +
> +	return nstoken;
>   }

This can be further simplified by using the netns_new() and netns_free(). Then 
create_netns() and remove_netns() can be removed from mptcp.c. Take a look at a 
recent usage in prog_tests/btf_skc_cls_ingress.c.

pw-bot: cr

>   
>   static void cleanup_netns(struct nstoken *nstoken)
> @@ -79,7 +85,7 @@ static void cleanup_netns(struct nstoken *nstoken)
>   	if (nstoken)
>   		close_netns(nstoken);
>   
> -	SYS_NOFAIL("ip netns del %s", NS_TEST);
> +	remove_netns(NS_TEST);
>   }
>   
>   static int start_mptcp_server(int family, const char *addr_str, __u16 port,