Re: [PATCH bpf-next v2 2/2] bpf, selftests: Add test case for cgroup skb to get net_cls classid helpers

On 9/18/24 12:45 AM, Feng zhou wrote:

From: Feng Zhou zhoufeng.zf@bytedance.com

This patch adds a test for cgroup skb to get classid.

Signed-off-by: Feng Zhou zhoufeng.zf@bytedance.com

.../bpf/prog_tests/cg_skb_get_classid.c | 87 +++++++++++++++++++ .../selftests/bpf/progs/cg_skb_get_classid.c | 19 ++++ 2 files changed, 106 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/cg_skb_get_classid.c create mode 100644 tools/testing/selftests/bpf/progs/cg_skb_get_classid.c

diff --git a/tools/testing/selftests/bpf/prog_tests/cg_skb_get_classid.c b/tools/testing/selftests/bpf/prog_tests/cg_skb_get_classid.c new file mode 100644 index 000000000000..13a5943c387d --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/cg_skb_get_classid.c @@ -0,0 +1,87 @@ +// SPDX-License-Identifier: GPL-2.0-only

+/*

• • Copyright 2024 Bytedance.
• */

+#include <test_progs.h>

+#include "cg_skb_get_classid.skel.h"

+#include "cgroup_helpers.h" +#include "network_helpers.h"

+static int run_test(int cgroup_fd, int server_fd) +{

• struct cg_skb_get_classid *skel;
• int fd, err = 0;
• skel = cg_skb_get_classid__open_and_load();
• if (!ASSERT_OK_PTR(skel, "skel_open"))

• return -1;
  

• skel->links.cg_skb_classid =

• bpf_program__attach_cgroup(skel->progs.cg_skb_classid,
  

• 			   cgroup_fd);
  

• if (!ASSERT_OK_PTR(skel->links.cg_skb_classid, "prog_attach")) {

• err = -1;
  

• goto out;
  

• }
• if (!ASSERT_OK(join_classid(), "join_classid")) {

• err = -1;
  

• goto out;
  

• }
• errno = 0;
• fd = connect_to_fd_opts(server_fd, NULL);
• if (fd >= 0) {

• if (skel->bss->classid != getpid()) {
  

• 	log_err("Get unexpected classid");
  

• 	err = -1;
  

• }
  

• close(fd);
  

• } else {

• log_err("Unexpected errno from connect to server");
  

• err = -1;
  

• }

+out:

• cg_skb_get_classid__destroy(skel);
• return err;

+}

+void test_cg_skb_get_classid(void) +{

• struct network_helper_opts opts = {};
• int server_fd, client_fd, cgroup_fd;
• static const int port = 60120;

Running a test with a specific port without netns could fail when test_progs is run in parallel (-j). e.g. cgroup_v1v2 is using the same port.

• /* Step 1: Check base connectivity works without any BPF. */
• server_fd = start_server(AF_INET, SOCK_STREAM, NULL, port, 0);
• if (!ASSERT_GE(server_fd, 0, "server_fd"))

• return;
  

• client_fd = connect_to_fd_opts(server_fd, &opts);
• if (!ASSERT_GE(client_fd, 0, "client_fd")) {

• close(server_fd);
  

• return;
  

• }
• close(client_fd);
• close(server_fd);

imo, this connection pre-test is unnecessary. I would remove it.

• /* Step 2: Check BPF prog attached to cgroups. */
• cgroup_fd = test__join_cgroup("/cg_skb_get_classid");
• if (!ASSERT_GE(cgroup_fd, 0, "cgroup_fd"))

• return;
  

• server_fd = start_server(AF_INET, SOCK_STREAM, NULL, port, 0);
• if (!ASSERT_GE(server_fd, 0, "server_fd")) {

• close(cgroup_fd);
  

• return;
  

• }
• setup_classid_environment();
• set_classid();
• ASSERT_OK(run_test(cgroup_fd, server_fd), "cg_skb_get_classid");

Please run this test under a netns and without specifying a particular port. connect_to_fd_opts will figure out the port used in server_fd.

Patch 1 lgtm.

Please add a few words to the cover letter also.

pw-bot: cr