Hello, This small series is another follow-up to [1], in which I misunderstood Martin's initial feedback (see [2]). I proposed to make tc-tunnel apply SO_REUSEPORT once server is brought up. This series updates start_server_addr to really apply Martin's proposal after his clarification [3]
[1] https://lore.kernel.org/bpf/20251031-tc_tunnel_improv-v1-0-0ffe44d27eda@boot... [2] https://lore.kernel.org/bpf/efa3540a-1f52-46ca-9f49-e631a5e3e48c@linux.dev/ [3] https://lore.kernel.org/bpf/4cbabdf1-af2c-490a-a41a-b40c1539c1cb@linux.dev/
Signed-off-by: Alexis Lothoré (eBPF Foundation) alexis.lothore@bootlin.com --- Alexis Lothoré (eBPF Foundation) (2): selftests/bpf: systematically add SO_REUSEADDR in start_server_addr selftests/bpf: use start_server_str rather than start_reuseport_server in tc_tunnel
tools/testing/selftests/bpf/network_helpers.c | 9 +++++++- .../selftests/bpf/prog_tests/test_tc_tunnel.c | 27 ++++++++++++---------- 2 files changed, 23 insertions(+), 13 deletions(-) --- base-commit: de0745f7cc98146c70a020bc3a1b73c7f3405282 change-id: 20251104-start-server-soreuseaddr-e442446e2d37
Best regards,
Some tests have to stop/start a server multiple time with the same listening address. Doing so without SO_REUSADDR leads to failures due to the socket still being in TIME_WAIT right after the first instance stop/before the second instance start. Instead of letting each test manually set SO_REUSEADDR on their servers, it can be done automatically by start_server_addr for all tests (and without any major downside).
Enforce SO_REUSEADDR in start_server_addr for all tests.
Signed-off-by: Alexis Lothoré (eBPF Foundation) alexis.lothore@bootlin.com --- tools/testing/selftests/bpf/network_helpers.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c index 8bb09167399a..e99b9c5e66a3 100644 --- a/tools/testing/selftests/bpf/network_helpers.c +++ b/tools/testing/selftests/bpf/network_helpers.c @@ -97,7 +97,8 @@ int settimeo(int fd, int timeout_ms) int start_server_addr(int type, const struct sockaddr_storage *addr, socklen_t addrlen, const struct network_helper_opts *opts) { - int fd; + + int on = 1, fd;
if (!opts) opts = &default_opts; @@ -111,6 +112,12 @@ int start_server_addr(int type, const struct sockaddr_storage *addr, socklen_t a if (settimeo(fd, opts->timeout_ms)) goto error_close;
+ if (type == SOCK_STREAM && + setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on))) { + log_err("Failed to enable SO_REUSEADDR"); + goto error_close; + } + if (opts->post_socket_cb && opts->post_socket_cb(fd, opts->cb_opts)) { log_err("Failed to call post_socket_cb");
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.lothore@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: close_netns(nstoken); }
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.lothore@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);
- 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;
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;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); }
Hello:
This series was applied to bpf/bpf-next.git (master) by Martin KaFai Lau martin.lau@kernel.org:
On Wed, 05 Nov 2025 09:22:47 +0100 you wrote:
Hello, This small series is another follow-up to [1], in which I misunderstood Martin's initial feedback (see [2]). I proposed to make tc-tunnel apply SO_REUSEPORT once server is brought up. This series updates start_server_addr to really apply Martin's proposal after his clarification [3]
[...]
Here is the summary with links: - [bpf-next,1/2] selftests/bpf: systematically add SO_REUSEADDR in start_server_addr https://git.kernel.org/bpf/bpf-next/c/38e36514fcb0 - [bpf-next,2/2] selftests/bpf: use start_server_str rather than start_reuseport_server in tc_tunnel https://git.kernel.org/bpf/bpf-next/c/5b7d6c91986e
You are awesome, thank you!
linux-kselftest-mirror@lists.linaro.org
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Alexis Lothoré (eBPF Foundation) -
Martin KaFai Lau -
patchwork-bot+netdevbpf＠kernel.org