Re: [PATCH bpf-next v4 2/2] selftests/bpf: Add mptcp subflow subtest

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

On 8/5/24 2:52 AM, Matthieu Baerts (NGI0) wrote:
> +static int endpoint_init(char *flags)
> +{
> +	SYS(fail, "ip -net %s link add veth1 type veth peer name veth2", NS_TEST);
> +	SYS(fail, "ip -net %s addr add %s/24 dev veth1", NS_TEST, ADDR_1);
> +	SYS(fail, "ip -net %s link set dev veth1 up", NS_TEST);
> +	SYS(fail, "ip -net %s addr add %s/24 dev veth2", NS_TEST, ADDR_2);
> +	SYS(fail, "ip -net %s link set dev veth2 up", NS_TEST);
> +	if (SYS_NOFAIL("ip -net %s mptcp endpoint add %s %s", NS_TEST, ADDR_2, flags)) {
> +		printf("'ip mptcp' not supported, skip this test.\n");
> +		test__skip();

It is always a skip now in bpf CI:

#171/3   mptcp/subflow:SKIP

This test is a useful addition for the bpf CI selftest.

It can't catch regression if it is always a skip in bpf CI though.

iproute2 needs to be updated (cc: Daniel Xu and Manu, the outdated iproute2 is 
something that came up multiple times).

Not sure when the iproute2 can be updated. In the mean time, your v3 is pretty 
close to getting pm_nl_ctl compiled. Is there other blocker on this?

> +		goto fail;
> +	}
> +
> +	return 0;
> +fail:
> +	return -1;
> +}
> +
> +static int _ss_search(char *src, char *dst, char *port, char *keyword)
> +{
> +	return SYS_NOFAIL("ip netns exec %s ss -enita src %s dst %s %s %d | grep -q '%s'",
> +			  NS_TEST, src, dst, port, PORT_1, keyword);
> +}
> +
> +static int ss_search(char *src, char *keyword)
> +{
> +	return _ss_search(src, ADDR_1, "dport", keyword);
> +}
> +
> +static void run_subflow(char *new)
> +{
> +	int server_fd, client_fd, err;
> +	char cc[TCP_CA_NAME_MAX];
> +	socklen_t len = sizeof(cc);
> +
> +	server_fd = start_mptcp_server(AF_INET, ADDR_1, PORT_1, 0);
> +	if (!ASSERT_GE(server_fd, 0, "start_mptcp_server"))
> +		return;
> +
> +	client_fd = connect_to_fd(server_fd, 0);
> +	if (!ASSERT_GE(client_fd, 0, "connect to fd"))
> +		goto fail;
> +
> +	err = getsockopt(server_fd, SOL_TCP, TCP_CONGESTION, cc, &len);
> +	if (!ASSERT_OK(err, "getsockopt(srv_fd, TCP_CONGESTION)"))
> +		goto fail;
> +
> +	send_byte(client_fd);
> +
> +	ASSERT_OK(ss_search(ADDR_1, "fwmark:0x1"), "ss_search fwmark:0x1");
> +	ASSERT_OK(ss_search(ADDR_2, "fwmark:0x2"), "ss_search fwmark:0x2");
> +	ASSERT_OK(ss_search(ADDR_1, new), "ss_search new cc");
> +	ASSERT_OK(ss_search(ADDR_2, cc), "ss_search default cc");

Is there a getsockopt way instead of ss + grep?