Re: [PATCH bpf-next v11 5/5] selftests/bpf: Add mptcpify test

On 8/3/23 10:07 PM, Geliang Tang wrote:

diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c index 3dc0ba2e7590..e6aafb4cfa8e 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_sock.skel.h" +#include "mptcpify.skel.h" char NS_TEST[32]; @@ -185,8 +186,105 @@ static void test_base(void) close(cgroup_fd); } +static void send_byte(int fd) +{

• char b = 0x55;
• ASSERT_EQ(write(fd, &b, sizeof(b)), 1, "send single byte");

+}

+static int verify_mptcpify(void) +{

• char cmd[256];
• int err = 0;
• /* Output of ss:

• *
  

• * ESTAB 0      0          127.0.0.1:44180    127.0.0.1:42225 cubic
  

• * ... tcp-ulp-mptcp flags:Mmec ...
  

• */
  

• snprintf(cmd, sizeof(cmd),

•  "ip netns exec %s ss -tOni | grep -q '%s'",
  

•  NS_TEST, "tcp-ulp-mptcp");
  

• if (!ASSERT_OK(system(cmd), "No tcp-ulp-mptcp found!"))

• err++;
  

• /* Output of nstat:

• *
  

• * #kernel
  

• * MPTcpExtMPCapableSYNACKRX       1                  0.0
  

• */
  

• snprintf(cmd, sizeof(cmd),

•  "ip netns exec %s nstat -asz %s | awk '%s' | grep -q '%s'",
  

•  NS_TEST, "MPTcpExtMPCapableSYNACKRX",
  

•  "NR==1 {next} {print $2}", "1");
  

• if (!ASSERT_OK(system(cmd), "No MPTcpExtMPCapableSYNACKRX found!"))

• err++;
  

The idea is to confirm the protocol has been changed. Is it more direct to use getsockopt(SO_PROTOCOL) on the created fd(s)?

• return err;

+}

+static int run_mptcpify(int cgroup_fd) +{

• int server_fd, client_fd, err = 0;
• struct mptcpify *mptcpify_skel;
• mptcpify_skel = mptcpify__open_and_load();
• if (!ASSERT_OK_PTR(mptcpify_skel, "skel_open_load"))

• return -EIO;
  

Although the return value does not matter much, -EIO looks weird for the error from mptcpify__open_and_load(). May be 'return libbpf_get_error(mptcpify_skel);'

-- pw-bot: cr

• err = mptcpify__attach(mptcpify_skel);
• if (!ASSERT_OK(err, "skel_attach"))

• goto out;
  

• /* without MPTCP */
• server_fd = start_server(AF_INET, SOCK_STREAM, NULL, 0, 0);
• if (!ASSERT_GE(server_fd, 0, "start_server")) {

• err = -EIO;
  

• goto out;
  

• }
• client_fd = connect_to_fd(server_fd, 0);
• if (!ASSERT_GE(client_fd, 0, "connect to fd")) {

• err = -EIO;
  

• goto close_server;
  

• }
• send_byte(client_fd);
• err = verify_mptcpify();
• close(client_fd);

+close_server:

• close(server_fd);

+out:

• mptcpify__destroy(mptcpify_skel);
• return err;

+}