This patch adds the round-robin BPF MPTCP scheduler test. Use sysctl to
set net.mptcp.scheduler to use this sched. Add a veth net device to
simulate the multiple addresses case. Use 'ip mptcp endpoint' command to
add this new endpoint to PM netlink.

Signed-off-by: Geliang Tang <geliang.tang@suse.com>
---
 .../testing/selftests/bpf/prog_tests/mptcp.c  | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
index 93a5739712ce..6303eba67fab 100644
--- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
+++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
@@ -6,6 +6,7 @@
 #include "cgroup_helpers.h"
 #include "network_helpers.h"
 #include "mptcp_bpf_first.skel.h"
+#include "mptcp_bpf_rr.skel.h"
 
 #ifndef TCP_CA_NAME_MAX
 #define TCP_CA_NAME_MAX	16
@@ -369,10 +370,47 @@ static void test_first(void)
 	mptcp_bpf_first__destroy(first_skel);
 }
 
+static void test_rr(void)
+{
+	struct mptcp_bpf_rr *rr_skel;
+	int server_fd, client_fd;
+	struct bpf_link *link;
+
+	rr_skel = mptcp_bpf_rr__open_and_load();
+	if (!ASSERT_OK_PTR(rr_skel, "bpf_rr__open_and_load"))
+		return;
+
+	link = bpf_map__attach_struct_ops(rr_skel->maps.rr);
+	if (!ASSERT_OK_PTR(link, "bpf_map__attach_struct_ops")) {
+		mptcp_bpf_rr__destroy(rr_skel);
+		return;
+	}
+
+	system("ip link add veth1 type veth");
+	system("ip addr add 10.0.1.1/24 dev veth1");
+	system("ip link set veth1 up");
+	system("ip mptcp endpoint add 10.0.1.1 subflow");
+	system("sysctl -qw net.mptcp.scheduler=bpf_rr");
+	server_fd = start_mptcp_server(AF_INET, NULL, 0, 0);
+	client_fd = connect_to_mptcp_fd(server_fd, 0);
+
+	send_data(server_fd, client_fd);
+
+	close(client_fd);
+	close(server_fd);
+	system("sysctl -qw net.mptcp.scheduler=default");
+	system("ip mptcp endpoint flush");
+	system("ip link del veth1");
+	bpf_link__destroy(link);
+	mptcp_bpf_rr__destroy(rr_skel);
+}
+
 void test_mptcp(void)
 {
 	if (test__start_subtest("base"))
 		test_base();
 	if (test__start_subtest("first"))
 		test_first();
+	if (test__start_subtest("rr"))
+		test_rr();
 }
-- 
2.34.1

On Wed, 11 May 2022, Geliang Tang wrote:

> This patch adds the round-robin BPF MPTCP scheduler test. Use sysctl to
> set net.mptcp.scheduler to use this sched. Add a veth net device to
> simulate the multiple addresses case. Use 'ip mptcp endpoint' command to
> add this new endpoint to PM netlink.
>
> Signed-off-by: Geliang Tang <geliang.tang@suse.com>
> ---
> .../testing/selftests/bpf/prog_tests/mptcp.c  | 38 +++++++++++++++++++
> 1 file changed, 38 insertions(+)
>
> diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> index 93a5739712ce..6303eba67fab 100644
> --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c
> +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c
> @@ -6,6 +6,7 @@
> #include "cgroup_helpers.h"
> #include "network_helpers.h"
> #include "mptcp_bpf_first.skel.h"
> +#include "mptcp_bpf_rr.skel.h"
>
> #ifndef TCP_CA_NAME_MAX
> #define TCP_CA_NAME_MAX	16
> @@ -369,10 +370,47 @@ static void test_first(void)
> 	mptcp_bpf_first__destroy(first_skel);
> }
>
> +static void test_rr(void)
> +{
> +	struct mptcp_bpf_rr *rr_skel;
> +	int server_fd, client_fd;
> +	struct bpf_link *link;
> +
> +	rr_skel = mptcp_bpf_rr__open_and_load();
> +	if (!ASSERT_OK_PTR(rr_skel, "bpf_rr__open_and_load"))
> +		return;
> +
> +	link = bpf_map__attach_struct_ops(rr_skel->maps.rr);
> +	if (!ASSERT_OK_PTR(link, "bpf_map__attach_struct_ops")) {
> +		mptcp_bpf_rr__destroy(rr_skel);
> +		return;
> +	}
> +
> +	system("ip link add veth1 type veth");
> +	system("ip addr add 10.0.1.1/24 dev veth1");
> +	system("ip link set veth1 up");
> +	system("ip mptcp endpoint add 10.0.1.1 subflow");
> +	system("sysctl -qw net.mptcp.scheduler=bpf_rr");
> +	server_fd = start_mptcp_server(AF_INET, NULL, 0, 0);
> +	client_fd = connect_to_mptcp_fd(server_fd, 0);
> +
> +	send_data(server_fd, client_fd);
> +

Is there a way to verify data was sent on both subflows? Maybe look at 
bytes_sent or segs_out in 'ss' output?

> +	close(client_fd);
> +	close(server_fd);
> +	system("sysctl -qw net.mptcp.scheduler=default");
> +	system("ip mptcp endpoint flush");
> +	system("ip link del veth1");
> +	bpf_link__destroy(link);
> +	mptcp_bpf_rr__destroy(rr_skel);
> +}
> +
> void test_mptcp(void)
> {
> 	if (test__start_subtest("base"))
> 		test_base();
> 	if (test__start_subtest("first"))
> 		test_first();
> +	if (test__start_subtest("rr"))
> +		test_rr();
> }
> -- 
> 2.34.1
>
>
>

--
Mat Martineau
Intel