Re: [PATCH bpf-next 2/2] selftests/bpf: use start_server_str rather than start_reuseport_server in tc_tunnel

[Martin KaFai Lau]

On 11/5/25 12:22 AM, Alexis Lothoré (eBPF Foundation) wrote:
Now that start_server_str enforces SO_REUSEADDR, there's no need to keep
using start_reusport_server in tc_tunnel, especially since it only uses
one server at a time.

Replace start_reuseport_server with start_server_str in tc_tunnel test.

Signed-off-by: Alexis Lothoré (eBPF Foundation) <alexis.loth...@bootlin.com>
---
  .../selftests/bpf/prog_tests/test_tc_tunnel.c      | 27 ++++++++++++----------
  1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/test_tc_tunnel.c 
b/tools/testing/selftests/bpf/prog_tests/test_tc_tunnel.c
index deea90aaefad..4d29256d8714 100644
--- a/tools/testing/selftests/bpf/prog_tests/test_tc_tunnel.c
+++ b/tools/testing/selftests/bpf/prog_tests/test_tc_tunnel.c
@@ -69,7 +69,7 @@ struct subtest_cfg {
        int client_egress_prog_fd;
        int server_ingress_prog_fd;
        char extra_decap_mod_args[TUNNEL_ARGS_MAX_LEN];
-       int *server_fd;
+       int server_fd;
  };
  
  struct connection {
@@ -135,16 +135,18 @@ static int run_server(struct subtest_cfg *cfg)
  {
        int family = cfg->ipproto == 6 ? AF_INET6 : AF_INET;
        struct nstoken *nstoken;
+       struct network_helper_opts opts = {
+               .timeout_ms = TIMEOUT_MS
+       };
  
  	nstoken = open_netns(SERVER_NS);
        if (!ASSERT_OK_PTR(nstoken, "open server ns"))
                return -1;
  
-	cfg->server_fd = start_reuseport_server(family, SOCK_STREAM,
-                                               cfg->server_addr, TEST_PORT,
-                                               TIMEOUT_MS, 1);
+       cfg->server_fd = start_server_str(family, SOCK_STREAM, cfg->server_addr,
+                                         TEST_PORT, &opts);
        close_netns(nstoken);
-       if (!ASSERT_OK_PTR(cfg->server_fd, "start server"))
+       if (!ASSERT_OK_FD(cfg->server_fd, "start server"))
                return -1;
  
  	return 0;
@@ -152,7 +154,7 @@ static int run_server(struct subtest_cfg *cfg)
  
  static void stop_server(struct subtest_cfg *cfg)
  {
-       free_fds(cfg->server_fd, 1);
+       close(cfg->server_fd);
  }
  
  static int check_server_rx_data(struct subtest_cfg *cfg,
@@ -188,7 +190,7 @@ static struct connection *connect_client_to_server(struct 
subtest_cfg *cfg)
                return NULL;
        }
  
-	server_fd = accept(*cfg->server_fd, NULL, NULL);
+       server_fd = accept(cfg->server_fd, NULL, NULL);
        if (server_fd < 0) {
                close(client_fd);
                free(conn);
@@ -394,29 +396,30 @@ static void run_test(struct subtest_cfg *cfg)
  
  	/* Basic communication must work */
        if (!ASSERT_OK(send_and_test_data(cfg, true), "connect without any 
encap"))
-               goto fail;
+               goto fail_close_server;
  
  	/* Attach encapsulation program to client */
        if (!ASSERT_OK(configure_encapsulation(cfg), "configure encapsulation"))
-               goto fail;
+               goto fail_close_server;
  
  	/* If supported, insert kernel decap module, connection must succeed */
        if (!cfg->expect_kern_decap_failure) {
                if (!ASSERT_OK(configure_kernel_decapsulation(cfg),
                                        "configure kernel decapsulation"))
-                       goto fail;
+                       goto fail_close_server;
                if (!ASSERT_OK(send_and_test_data(cfg, true),
                               "connect with encap prog and kern decap"))
-                       goto fail;
+                       goto fail_close_server;
        }
  
  	/* Replace kernel decapsulation with BPF decapsulation, test must pass */
        if (!ASSERT_OK(configure_ebpf_decapsulation(cfg), "configure ebpf 
decapsulation"))
-               goto fail;
+               goto fail_close_server;
        ASSERT_OK(send_and_test_data(cfg, true), "connect with encap and decap 
progs");
  
  fail:
        stop_server(cfg);
+fail_close_server:

The "fail" and "fail_close_server" ordering is incorrect. I took this 
chance to simplify it by doing run_server() before open_netns().

Applied. Thanks.
        close_netns(nstoken);
  }