From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 204FEC433DF for ; Mon, 3 Aug 2020 23:10:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 32ABB2065E for ; Mon, 3 Aug 2020 23:10:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="e1yMYej7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729139AbgHCXKt (ORCPT ); Mon, 3 Aug 2020 19:10:49 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:29970 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728662AbgHCXKt (ORCPT ); Mon, 3 Aug 2020 19:10:49 -0400 Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 073Mov6O009358 for ; Mon, 3 Aug 2020 16:10:48 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=bvt3I0oCfzjJXyCrbToSJXIJ9nR6dE9Azh74le8JbrQ=; b=e1yMYej7/wUuv/2E+iAPCaibW4UKmiMVT4KYkULTxPuc56LHNrBQ9RiOVzq0DD/l4CnW wCHDUMugwRnQGlXYB5DLAuEhPObNaSISP8Ju92+DNVgeWAuG0+WFjyxIOxYA3rbS420x gQeqyghyGXV8S9o1xuV2RxF5z3m8tR+54l4= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 32nr3by49n-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 03 Aug 2020 16:10:48 -0700 Received: from intmgw002.08.frc2.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:82::f) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Mon, 3 Aug 2020 16:10:47 -0700 Received: by devbig005.ftw2.facebook.com (Postfix, from userid 6611) id 70F352943872; Mon, 3 Aug 2020 16:10:39 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Martin KaFai Lau Smtp-Origin-Hostname: devbig005.ftw2.facebook.com To: CC: Alexei Starovoitov , Daniel Borkmann , Eric Dumazet , , Lawrence Brakmo , Neal Cardwell , , Yuchung Cheng Smtp-Origin-Cluster: ftw2c04 Subject: [RFC PATCH v4 bpf-next 04/12] tcp: Add saw_unknown to struct tcp_options_received Date: Mon, 3 Aug 2020 16:10:39 -0700 Message-ID: <20200803231039.2682896-1-kafai@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200803231013.2681560-1-kafai@fb.com> References: <20200803231013.2681560-1-kafai@fb.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235,18.0.687 definitions=2020-08-03_15:2020-08-03,2020-08-03 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 adultscore=0 priorityscore=1501 lowpriorityscore=0 malwarescore=0 impostorscore=0 mlxscore=0 suspectscore=13 phishscore=0 bulkscore=0 mlxlogscore=999 clxscore=1015 spamscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2008030158 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org In a later patch, the bpf prog only wants to be called to handle a header option if that particular header option cannot be handled by the kernel. This unknown option could be written by the peer's bpf-prog. It could also be a new standard option that the running kernel does not support it while a bpf-prog can handle it. This patch adds a "saw_unknown" bit to "struct tcp_options_received" and it uses an existing one byte hole to do that. "saw_unknown" will be set in tcp_parse_options() if it sees an option that the kernel cannot handle. Signed-off-by: Martin KaFai Lau --- include/linux/tcp.h | 2 ++ net/ipv4/tcp_input.c | 22 ++++++++++++++++------ 2 files changed, 18 insertions(+), 6 deletions(-) diff --git a/include/linux/tcp.h b/include/linux/tcp.h index 5528912dc468..981145691f60 100644 --- a/include/linux/tcp.h +++ b/include/linux/tcp.h @@ -92,6 +92,8 @@ struct tcp_options_received { smc_ok : 1, /* SMC seen on SYN packet */ snd_wscale : 4, /* Window scaling received from sender */ rcv_wscale : 4; /* Window scaling to send to receiver */ + u8 saw_unknown:1, /* Received unknown option */ + unused:7; u8 num_sacks; /* Number of SACK blocks */ u16 user_mss; /* mss requested by user in ioctl */ u16 mss_clamp; /* Maximal mss, negotiated at connection setup */ diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 05d0818c3e31..c1d2fb507701 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -3799,7 +3799,7 @@ static void tcp_parse_fastopen_option(int len, cons= t unsigned char *cookie, foc->exp =3D exp_opt; } =20 -static void smc_parse_options(const struct tcphdr *th, +static bool smc_parse_options(const struct tcphdr *th, struct tcp_options_received *opt_rx, const unsigned char *ptr, int opsize) @@ -3808,10 +3808,13 @@ static void smc_parse_options(const struct tcphdr= *th, if (static_branch_unlikely(&tcp_have_smc)) { if (th->syn && !(opsize & 1) && opsize >=3D TCPOLEN_EXP_SMC_BASE && - get_unaligned_be32(ptr) =3D=3D TCPOPT_SMC_MAGIC) + get_unaligned_be32(ptr) =3D=3D TCPOPT_SMC_MAGIC) { opt_rx->smc_ok =3D 1; + return true; + } } #endif + return false; } =20 /* Try to parse the MSS option from the TCP header. Return 0 on failure,= clamped @@ -3872,6 +3875,7 @@ void tcp_parse_options(const struct net *net, =20 ptr =3D (const unsigned char *)(th + 1); opt_rx->saw_tstamp =3D 0; + opt_rx->saw_unknown =3D 0; =20 while (length > 0) { int opcode =3D *ptr++; @@ -3962,15 +3966,21 @@ void tcp_parse_options(const struct net *net, */ if (opsize >=3D TCPOLEN_EXP_FASTOPEN_BASE && get_unaligned_be16(ptr) =3D=3D - TCPOPT_FASTOPEN_MAGIC) + TCPOPT_FASTOPEN_MAGIC) { tcp_parse_fastopen_option(opsize - TCPOLEN_EXP_FASTOPEN_BASE, ptr + 2, th->syn, foc, true); - else - smc_parse_options(th, opt_rx, ptr, - opsize); + break; + } + + if (smc_parse_options(th, opt_rx, ptr, opsize)) + break; + + opt_rx->saw_unknown =3D 1; break; =20 + default: + opt_rx->saw_unknown =3D 1; } ptr +=3D opsize-2; length -=3D opsize; --=20 2.24.1