From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-183.mta0.migadu.com (out-183.mta0.migadu.com [91.218.175.183]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F4C43B2FFF for ; Fri, 17 Apr 2026 09:21:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.183 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776417679; cv=none; b=qJMixftu7O65dAnfb9nNDcfItYlZnm+/06kaLao4Yt2/M5Io2yBkkMAOM1WEgGICnTfdiiAwzVPhUiSc5xFZ5qXtu2jTWsz85eq6lMEfaFFrazPL0STgw3h8rbqfnWqcCAxJ/xwHAYDxGkPhFfnhi7Rk0rxnrw+ndCy7H8Sej1w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776417679; c=relaxed/simple; bh=M6ErwwDPUWYN/stgA9KjTyOFuDDepXWfSieVtMbfiIE=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=N2GND+RoDtHnWABBWxiogJEsOGAu5dtYYCIY+QvdiErghXaMeNcQYZFny8A/UjI14LBcHuBATdMZoAAx82TDZQRHHZKKZH6afhffUVz2d916+pC+ykCNWW/oSlulDA66RiMbm5mUIa6OiL+9LVFPZbJVrbXxbdwHo3FcJmhwvss= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=jq8U88dj; arc=none smtp.client-ip=91.218.175.183 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="jq8U88dj" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1776417673; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=q7l7fufO2xt/WoYOZ4wD7hIr19kUg279ukInRFdUToo=; b=jq8U88djAv55h31U43KcrgH5i+vZWxwyBDgaYAPFt7qs2MoTbn5knw/LiGGmlz5iNPpLkm MUTggw17haZVU/IFGFp5Qht6DfdzngzjCb8dwpIot/5yZCLVCKGKgCdq7AQbejxKmWNV/5 aux1TmMKNRKkBis9krKWNti0FUqO38s= From: KaFai Wan To: martin.lau@linux.dev, daniel@iogearbox.net, john.fastabend@gmail.com, sdf@fomichev.me, ast@kernel.org, andrii@kernel.org, eddyz87@gmail.com, memxor@gmail.com, song@kernel.org, yonghong.song@linux.dev, jolsa@kernel.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, shuah@kernel.org, jiayuan.chen@linux.dev, kafai.wan@linux.dev, bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH bpf v3 2/2] selftests/bpf: Test TCP_NODELAY in TCP hdr opt callbacks Date: Fri, 17 Apr 2026 17:20:35 +0800 Message-ID: <20260417092035.2299913-3-kafai.wan@linux.dev> In-Reply-To: <20260417092035.2299913-1-kafai.wan@linux.dev> References: <20260417092035.2299913-1-kafai.wan@linux.dev> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Add a sockops selftest for the TCP_NODELAY restriction in BPF_SOCK_OPS_HDR_OPT_LEN_CB and BPF_SOCK_OPS_WRITE_HDR_OPT_CB. With BPF_SOCK_OPS_WRITE_HDR_OPT_CB_FLAG enabled, bpf_setsockopt(TCP_NODELAY) returns -EOPNOTSUPP from BPF_SOCK_OPS_HDR_OPT_LEN_CB and BPF_SOCK_OPS_WRITE_HDR_OPT_CB, avoiding unbounded recursion and kernel stack overflow. Other cases continue to work as before, including BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB and user space setsockopt(TCP_NODELAY). Signed-off-by: KaFai Wan --- .../selftests/bpf/prog_tests/tcp_hdr_options.c | 12 +++++++++++- .../bpf/progs/test_misc_tcp_hdr_options.c | 15 ++++++++++++++- 2 files changed, 25 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c b/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c index 56685fc03c7e..7b9dbbb84316 100644 --- a/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c +++ b/tools/testing/selftests/bpf/prog_tests/tcp_hdr_options.c @@ -461,7 +461,7 @@ static void misc(void) const unsigned int nr_data = 2; struct bpf_link *link; struct sk_fds sk_fds; - int i, ret; + int i, ret, true_val = 1; lport_linum_map_fd = bpf_map__fd(misc_skel->maps.lport_linum_map); @@ -477,6 +477,10 @@ static void misc(void) return; } + ret = setsockopt(sk_fds.active_fd, SOL_TCP, TCP_NODELAY, &true_val, sizeof(true_val)); + if (!ASSERT_OK(ret, "setsockopt(TCP_NODELAY)")) + goto check_linum; + for (i = 0; i < nr_data; i++) { /* MSG_EOR to ensure skb will not be combined */ ret = send(sk_fds.active_fd, send_msg, sizeof(send_msg), @@ -507,6 +511,12 @@ static void misc(void) ASSERT_EQ(misc_skel->bss->nr_hwtstamp, 0, "nr_hwtstamp"); + ASSERT_TRUE(misc_skel->data->nodelay_est_ok, "unexpected nodelay_est_ok"); + + ASSERT_TRUE(misc_skel->data->nodelay_hdr_len_err, "unexpected nodelay_hdr_len_err"); + + ASSERT_TRUE(misc_skel->data->nodelay_write_hdr_err, "unexpected nodelay_write_hdr_err"); + check_linum: ASSERT_FALSE(check_error_linum(&sk_fds), "check_error_linum"); sk_fds_close(&sk_fds); diff --git a/tools/testing/selftests/bpf/progs/test_misc_tcp_hdr_options.c b/tools/testing/selftests/bpf/progs/test_misc_tcp_hdr_options.c index d487153a839d..a02e28d9db2e 100644 --- a/tools/testing/selftests/bpf/progs/test_misc_tcp_hdr_options.c +++ b/tools/testing/selftests/bpf/progs/test_misc_tcp_hdr_options.c @@ -29,6 +29,10 @@ unsigned int nr_syn = 0; unsigned int nr_fin = 0; unsigned int nr_hwtstamp = 0; +bool nodelay_est_ok = true; +bool nodelay_hdr_len_err = true; +bool nodelay_write_hdr_err = true; + /* Check the header received from the active side */ static int __check_active_hdr_in(struct bpf_sock_ops *skops, bool check_syn) { @@ -300,7 +304,7 @@ static int handle_passive_estab(struct bpf_sock_ops *skops) SEC("sockops") int misc_estab(struct bpf_sock_ops *skops) { - int true_val = 1; + int true_val = 1, false_val = 0, ret; switch (skops->op) { case BPF_SOCK_OPS_TCP_LISTEN_CB: @@ -316,10 +320,19 @@ int misc_estab(struct bpf_sock_ops *skops) case BPF_SOCK_OPS_PARSE_HDR_OPT_CB: return handle_parse_hdr(skops); case BPF_SOCK_OPS_HDR_OPT_LEN_CB: + ret = bpf_setsockopt(skops, SOL_TCP, TCP_NODELAY, &true_val, sizeof(true_val)); + nodelay_hdr_len_err &= ret == -EOPNOTSUPP; + return handle_hdr_opt_len(skops); case BPF_SOCK_OPS_WRITE_HDR_OPT_CB: + ret = bpf_setsockopt(skops, SOL_TCP, TCP_NODELAY, &true_val, sizeof(true_val)); + nodelay_write_hdr_err &= ret == -EOPNOTSUPP; + return handle_write_hdr_opt(skops); case BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB: + ret = bpf_setsockopt(skops, SOL_TCP, TCP_NODELAY, &false_val, sizeof(false_val)); + nodelay_est_ok &= ret == 0; + return handle_passive_estab(skops); } -- 2.43.0