From nobody Fri Jun 19 12:01:40 2026 Received: from out-188.mta0.migadu.com (out-188.mta0.migadu.com [91.218.175.188]) (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 8359829405 for ; Mon, 27 Apr 2026 00:10:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.188 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777248631; cv=none; b=cOuD9kq0ySQoYzZQm5FK3sJ508UlVO3thHSaTNSzMReNxtQfosb5gNv9pdEcmPeCLECya0OXfPZneFDoNjeyz2CykNsC+CcO72nwOgzQMj9PVp4lIt8my2F3KLtWQpkFxB308svRUAk1qbo8S6KJqTqHP52OvKeOoDOlWDBNTMA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777248631; c=relaxed/simple; bh=HE7BxprbWbvSxOEmJLllT42EXXyU1vH12u1BgeuGD+M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=E6u8bp5rtnZ7SnBg1rrZXt6BxgqoMDbVUDlGVkfHufbh6JP1ZlyWyjSAQ/rW/R6DVhDRLPgKOdBTl/FEZrjEt3Pr3lT+5x+SHkUHs19EHfOjnRUDaNmX4tnoZvnZOy4kxCts2E/xDb7WTZJYV8EjdDXYA6QSECTuKH7eaYqJ8LM= 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=MgXJNSXW; arc=none smtp.client-ip=91.218.175.188 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="MgXJNSXW" 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=1777248626; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=thqy/C0mcjHd+pIJXdyZabcH7rwCZ8ZhkEPpLz/0b2U=; b=MgXJNSXWFUFc/vLi3GY673iI5EGILgil244GMF7qkt6UiOfYxsbbgCHLB2BZrnLmgmit6N wOMn9/Vx+CqASwJgyU04VsMQ5vr8XxT1R7aOH3POMIYihjGX5jjAZOmCrXXuWyGjN3o/z2 dKKY03EgHDZ/OiNPBAaOQtne2XbYTcg= From: Jiayuan Chen To: bpf@vger.kernel.org Cc: Jiayuan Chen , Kuniyuki Iwashima , Eric Dumazet , Neal Cardwell , "David S. Miller" , Jakub Kicinski , Paolo Abeni , Simon Horman , David Ahern , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Kumar Kartikeya Dwivedi , Song Liu , Yonghong Song , Jiri Olsa , Shuah Khan , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH bpf-next v3 1/2] net: add missing syncookie statistics for BPF custom syncookies Date: Mon, 27 Apr 2026 08:09:50 +0800 Message-ID: <20260427001006.14465-2-jiayuan.chen@linux.dev> In-Reply-To: <20260427001006.14465-1-jiayuan.chen@linux.dev> References: <20260427001006.14465-1-jiayuan.chen@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" 1. Replace IS_ENABLED(CONFIG_BPF) with CONFIG_BPF_SYSCALL for cookie_bpf_ok() and cookie_bpf_check(). CONFIG_BPF is selected by CONFIG_NET unconditionally, so IS_ENABLED(CONFIG_BPF) is always true and provides no real guard. CONFIG_BPF_SYSCALL is the correct config for BPF program functionality. 2. Remove the CONFIG_BPF guard around struct bpf_tcp_req_attrs. Since CONFIG_BPF is always selected by CONFIG_NET the guard is a no-op, and the struct is referenced by bpf_sk_assign_tcp_reqsk() in net/core/filter.c which is compiled unconditionally, so its visibility is not actually conditional on BPF being enabled. 3. Fix mismatched declaration of cookie_bpf_check() between the CONFIG_BPF_SYSCALL and stub paths: the real definition takes 'struct net *net' but the declaration in the header did not. Add the net parameter to the declaration and all call sites. 4. Add missing LINUX_MIB_SYNCOOKIESRECV and LINUX_MIB_SYNCOOKIESFAILED statistics in cookie_bpf_check(), so that BPF custom syncookie validation is accounted for in SNMP counters just like the non-BPF path. Compile-tested with CONFIG_BPF_SYSCALL=3Dy and CONFIG_BPF_SYSCALL not set. Signed-off-by: Jiayuan Chen Reviewed-by: Kuniyuki Iwashima --- include/net/tcp.h | 7 +++---- net/ipv4/syncookies.c | 10 +++++++--- net/ipv6/syncookies.c | 2 +- 3 files changed, 11 insertions(+), 8 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index dfa52ceefd23b..0e3e43c7a89ce 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -599,7 +599,6 @@ struct request_sock *cookie_tcp_reqsk_alloc(const struc= t request_sock_ops *ops, struct tcp_options_received *tcp_opt, int mss, u32 tsoff); =20 -#if IS_ENABLED(CONFIG_BPF) struct bpf_tcp_req_attrs { u32 rcv_tsval; u32 rcv_tsecr; @@ -613,7 +612,6 @@ struct bpf_tcp_req_attrs { u8 usec_ts_ok; u8 reserved[3]; }; -#endif =20 #ifdef CONFIG_SYN_COOKIES =20 @@ -716,13 +714,14 @@ static inline bool cookie_ecn_ok(const struct net *ne= t, const struct dst_entry * dst_feature(dst, RTAX_FEATURE_ECN); } =20 -#if IS_ENABLED(CONFIG_BPF) +#ifdef CONFIG_BPF_SYSCALL static inline bool cookie_bpf_ok(struct sk_buff *skb) { return skb->sk; } =20 -struct request_sock *cookie_bpf_check(struct sock *sk, struct sk_buff *skb= ); +struct request_sock *cookie_bpf_check(struct net *net, struct sock *sk, + struct sk_buff *skb); #else static inline bool cookie_bpf_ok(struct sk_buff *skb) { diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index df479277fb801..9251d4a15c888 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -294,8 +294,9 @@ static int cookie_tcp_reqsk_init(struct sock *sk, struc= t sk_buff *skb, return 0; } =20 -#if IS_ENABLED(CONFIG_BPF) -struct request_sock *cookie_bpf_check(struct sock *sk, struct sk_buff *skb) +#ifdef CONFIG_BPF_SYSCALL +struct request_sock *cookie_bpf_check(struct net *net, struct sock *sk, + struct sk_buff *skb) { struct request_sock *req =3D inet_reqsk(skb->sk); =20 @@ -305,6 +306,9 @@ struct request_sock *cookie_bpf_check(struct sock *sk, = struct sk_buff *skb) if (cookie_tcp_reqsk_init(sk, skb, req)) { reqsk_free(req); req =3D NULL; + __NET_INC_STATS(net, LINUX_MIB_SYNCOOKIESFAILED); + } else { + __NET_INC_STATS(net, LINUX_MIB_SYNCOOKIESRECV); } =20 return req; @@ -419,7 +423,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk= _buff *skb) goto out; =20 if (cookie_bpf_ok(skb)) { - req =3D cookie_bpf_check(sk, skb); + req =3D cookie_bpf_check(net, sk, skb); } else { req =3D cookie_tcp_check(net, sk, skb); if (IS_ERR(req)) diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index 4f6f0d751d6c5..111d7a41d9573 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -190,7 +190,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk= _buff *skb) goto out; =20 if (cookie_bpf_ok(skb)) { - req =3D cookie_bpf_check(sk, skb); + req =3D cookie_bpf_check(net, sk, skb); } else { req =3D cookie_tcp_check(net, sk, skb); if (IS_ERR(req)) --=20 2.43.0 From nobody Fri Jun 19 12:01:40 2026 Received: from out-174.mta0.migadu.com (out-174.mta0.migadu.com [91.218.175.174]) (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 5BB1F11CBA for ; Mon, 27 Apr 2026 00:10:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.174 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777248641; cv=none; b=sAQ5IujKcu1vZgI5ikxPouX3QqdQVE6FbByc0Ffde7B9pvoCYCFQ+PuaeEDUAI0mGk4M7y/NkarQqv6kYYiosLWC4nHl2HfkjlURqsenixI3VlQk9Oi0oEUc0jSvfLovEmySVZ+wqDhjM2TVg70rMhTIW8r2mgJDs5Ts6H5wROk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777248641; c=relaxed/simple; bh=p6e2XGgZSjjNTrSHVSgPEC5G2Z45vegMyI/0HX5jKsA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Zzm+YlEBQX+CZKhvRx6CLuSbpYns0pOWl4LWTT9YEhvcXnauGBTr6WFooCn6tGVuZ9GQOQlLILSeyryeCrj+TeZDXIJg89vbtMvasOkptBBi42O1vkTaEjJPsPyd/LD2COgq7BuI6vsKcEoNqx9ZWWAHRYDzmd7ZaVyaXcV4Gjc= 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=g6jALT1F; arc=none smtp.client-ip=91.218.175.174 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="g6jALT1F" 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=1777248637; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=KTaTeyV4fkdCC2Z7sy1+GXBRRQ6mxdqx//Ymq3ZlT+w=; b=g6jALT1FZTfka9IgXraBhS6YV5MHXVA1S3/2pWR7pOsVdmQwvgLOGwVHlHio7qJFdsC6mz H/LuvTs7iXGKNiLF01wDVrVBb5gGgkk34yniKSkxqdpVXq6f0W1FdUmFKJTT/K+GUZE8Hz BlsftM3s5YcKGD8u6ybu47k7J1VWTwQ= From: Jiayuan Chen To: bpf@vger.kernel.org Cc: Jiayuan Chen , Kuniyuki Iwashima , Eric Dumazet , Neal Cardwell , "David S. Miller" , Jakub Kicinski , Paolo Abeni , Simon Horman , David Ahern , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Kumar Kartikeya Dwivedi , Song Liu , Yonghong Song , Jiri Olsa , Shuah Khan , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH bpf-next v3 2/2] selftests/bpf: verify syncookie statistics in tcp_custom_syncookie Date: Mon, 27 Apr 2026 08:09:51 +0800 Message-ID: <20260427001006.14465-3-jiayuan.chen@linux.dev> In-Reply-To: <20260427001006.14465-1-jiayuan.chen@linux.dev> References: <20260427001006.14465-1-jiayuan.chen@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Add read_tcpext_snmp() helper to network_helpers which reads a TcpExt SNMP counter via nstat, and use it in the tcp_custom_syncookie test to verify that LINUX_MIB_SYNCOOKIESRECV is incremented and LINUX_MIB_SYNCOOKIESFAILED stays unchanged across a successful BPF custom syncookie validation. The delta is captured between start_server() and accept(), which covers the full SYN/ACK/cookie-check path for one connection. Signed-off-by: Jiayuan Chen Reviewed-by: Kuniyuki Iwashima --- tools/testing/selftests/bpf/network_helpers.c | 22 +++++++++++++++++++ tools/testing/selftests/bpf/network_helpers.h | 1 + .../bpf/prog_tests/tcp_custom_syncookie.c | 20 +++++++++++++++++ 3 files changed, 43 insertions(+) diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/= selftests/bpf/network_helpers.c index b82f572641b7d..3388dd5112b6f 100644 --- a/tools/testing/selftests/bpf/network_helpers.c +++ b/tools/testing/selftests/bpf/network_helpers.c @@ -621,6 +621,28 @@ int get_socket_local_port(int sock_fd) return -1; } =20 +int read_tcpext_snmp(const char *name, unsigned long *val) +{ + char cmd[128], buf[128]; + int ret =3D 0; + FILE *f; + + snprintf(cmd, sizeof(cmd), + "nstat -az TcpExt%s | awk '/TcpExt/ {print $2}'", name); + f =3D popen(cmd, "r"); + if (!f) + return -errno; + + if (!fgets(buf, sizeof(buf), f)) { + ret =3D ferror(f) ? -errno : -ENODATA; + goto out; + } + *val =3D strtoul(buf, NULL, 10); +out: + pclose(f); + return ret; +} + int get_hw_ring_size(char *ifname, struct ethtool_ringparam *ring_param) { struct ifreq ifr =3D {0}; diff --git a/tools/testing/selftests/bpf/network_helpers.h b/tools/testing/= selftests/bpf/network_helpers.h index 79a010c88e11c..c53cd781df6e6 100644 --- a/tools/testing/selftests/bpf/network_helpers.h +++ b/tools/testing/selftests/bpf/network_helpers.h @@ -84,6 +84,7 @@ int make_sockaddr(int family, const char *addr_str, __u16= port, struct sockaddr_storage *addr, socklen_t *len); char *ping_command(int family); int get_socket_local_port(int sock_fd); +int read_tcpext_snmp(const char *name, unsigned long *val); int get_hw_ring_size(char *ifname, struct ethtool_ringparam *ring_param); int set_hw_ring_size(char *ifname, struct ethtool_ringparam *ring_param); =20 diff --git a/tools/testing/selftests/bpf/prog_tests/tcp_custom_syncookie.c = b/tools/testing/selftests/bpf/prog_tests/tcp_custom_syncookie.c index eaf441dc7e79b..00d5c32674fc9 100644 --- a/tools/testing/selftests/bpf/prog_tests/tcp_custom_syncookie.c +++ b/tools/testing/selftests/bpf/prog_tests/tcp_custom_syncookie.c @@ -91,12 +91,21 @@ static void transfer_message(int sender, int receiver) =20 static void create_connection(struct test_tcp_custom_syncookie_case *test_= case) { + unsigned long failed_before, failed_after; + unsigned long recv_before, recv_after; int server, client, child; =20 server =3D start_server(test_case->family, test_case->type, test_case->ad= dr, 0, 0); if (!ASSERT_NEQ(server, -1, "start_server")) return; =20 + if (!ASSERT_OK(read_tcpext_snmp("SyncookiesRecv", &recv_before), + "read SyncookiesRecv before")) + goto close_server; + if (!ASSERT_OK(read_tcpext_snmp("SyncookiesFailed", &failed_before), + "read SyncookiesFailed before")) + goto close_server; + client =3D connect_to_fd(server, 0); if (!ASSERT_NEQ(client, -1, "connect_to_fd")) goto close_server; @@ -105,9 +114,20 @@ static void create_connection(struct test_tcp_custom_s= yncookie_case *test_case) if (!ASSERT_NEQ(child, -1, "accept")) goto close_client; =20 + if (!ASSERT_OK(read_tcpext_snmp("SyncookiesRecv", &recv_after), + "read SyncookiesRecv after")) + goto close_child; + if (!ASSERT_OK(read_tcpext_snmp("SyncookiesFailed", &failed_after), + "read SyncookiesFailed after")) + goto close_child; + + ASSERT_EQ(recv_after - recv_before, 1, "SyncookiesRecv delta"); + ASSERT_EQ(failed_after - failed_before, 0, "SyncookiesFailed delta"); + transfer_message(client, child); transfer_message(child, client); =20 +close_child: close(child); close_client: close(client); --=20 2.43.0