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=-11.1 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,MSGID_FROM_MTA_HEADER,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 D04E6C43460 for ; Fri, 21 May 2021 04:47:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AB5546135C for ; Fri, 21 May 2021 04:47:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239316AbhEUEtU (ORCPT ); Fri, 21 May 2021 00:49:20 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:52698 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S232956AbhEUEtS (ORCPT ); Fri, 21 May 2021 00:49:18 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.43/8.16.0.43) with SMTP id 14L4idcn010720; Thu, 20 May 2021 21:47:33 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=date : from : to : cc : subject : message-id : references : content-type : in-reply-to : mime-version; s=facebook; bh=oZTLwdTSqBiHK3kOXkK2n/XaJijMcps9iTsYl6uO0F0=; b=Axn6T7wYAz82Wud5IQTQYLthDoaYoQPNorYW3Xxpv9QV4uha0btsSUBi/lkBR8OdgDip YIlGS7d1ODYZRvwlfE3wFRO7fyrUNNDzdIjFX+7vPjozCC8E4qR84rOk459Ed/E5tg63 w+jBZth5VllabQLu9h7JxLfIvrWxrqSsD5g= Received: from mail.thefacebook.com ([163.114.132.120]) by m0089730.ppops.net with ESMTP id 38p3a5gt4b-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Thu, 20 May 2021 21:47:32 -0700 Received: from NAM02-SN1-obe.outbound.protection.outlook.com (100.104.98.9) by o365-in.thefacebook.com (100.104.94.198) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Thu, 20 May 2021 21:47:31 -0700 ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=KD8+rwi7Aj2u8LTYD3MoIrjLYFDwpby8QTu7d+5zwZWDyij5bBB2JmEJN++pfwHDw5fz/5NYELWhVv8TkKtK8GeHtc9CGcWUrSFjqO4W9SDsE8qMrfpFe49JMryq2UFN9nuQW3WaRu2iDEXmM3zrS18qbK+hBQCSDDDe3MnWIU4HhYqVRGOIEAYWL35qRLlQb6byT4/pgAEnB5It7IE2VD5jt3alB+sCnnoNp5+SEgBCNzm9mvGzZutqm9kMwIecgllC8WScxwmZY0EigQ78LiNkqjJC3a0URG+BW8/jhacdMVe8yLhRFtE0VeRdzTQ2cJHuDnY7DW4cUIdjYYgZyw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=oZTLwdTSqBiHK3kOXkK2n/XaJijMcps9iTsYl6uO0F0=; b=Ue/GkwCT+xap16mf8D0yWz1XDyzsuOZ+EO9CUi0Yxyi3wAEKU9QNG269P9csmMk7zfBffuUJJqlN2OfsG5srFGlBBYfdfy4AIAxxg7Ktni8xcI5fQffpH65/bpkCpmlJxTdu+jrDjpufwTQ6P6X7KM+NRV+eD3zSusQ0xzpu+0tc/Jl0TYiP3RO3+SZJMeU6+2y6Debv7E+xbQPEKtNLtdR0QpK7T+5E8AEgIUZMgvpaHYxiiw8opm0Oixvf/AvM11y4/XSy3K8dGpUgKglhREGqbQeC32x2fCeCZtSMIkvpdhOszhRZkVy2JhXxZ1esnHGrdPQ6d+Kk2Bgm+u1Oow== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=fb.com; dmarc=pass action=none header.from=fb.com; dkim=pass header.d=fb.com; arc=none Authentication-Results: amazon.co.jp; dkim=none (message not signed) header.d=none;amazon.co.jp; dmarc=none action=none header.from=fb.com; Received: from BY5PR15MB3571.namprd15.prod.outlook.com (2603:10b6:a03:1f6::32) by BY5PR15MB3714.namprd15.prod.outlook.com (2603:10b6:a03:1f7::10) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4150.25; Fri, 21 May 2021 04:47:29 +0000 Received: from BY5PR15MB3571.namprd15.prod.outlook.com ([fe80::718a:4142:4c92:732f]) by BY5PR15MB3571.namprd15.prod.outlook.com ([fe80::718a:4142:4c92:732f%6]) with mapi id 15.20.4150.023; Fri, 21 May 2021 04:47:29 +0000 Date: Thu, 20 May 2021 21:47:25 -0700 From: Martin KaFai Lau To: Kuniyuki Iwashima CC: , , , , , , , , , , Subject: Re: [PATCH v6 bpf-next 03/11] tcp: Keep TCP_CLOSE sockets in the reuseport group. Message-ID: <20210521044725.acvvp3qoj5tk4xts@kafai-mbp.dhcp.thefacebook.com> References: <20210520233906.c7yphwjrstqmhfk6@kafai-mbp.dhcp.thefacebook.com> <20210521002639.20533-1-kuniyu@amazon.co.jp> Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20210521002639.20533-1-kuniyu@amazon.co.jp> X-Originating-IP: [2620:10d:c090:400::5:e31a] X-ClientProxiedBy: MW4PR03CA0354.namprd03.prod.outlook.com (2603:10b6:303:dc::29) To BY5PR15MB3571.namprd15.prod.outlook.com (2603:10b6:a03:1f6::32) MIME-Version: 1.0 X-MS-Exchange-MessageSentRepresentingType: 1 Received: from kafai-mbp.dhcp.thefacebook.com (2620:10d:c090:400::5:e31a) by MW4PR03CA0354.namprd03.prod.outlook.com (2603:10b6:303:dc::29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.4150.23 via Frontend Transport; Fri, 21 May 2021 04:47:27 +0000 X-MS-PublicTrafficType: Email X-MS-Office365-Filtering-Correlation-Id: cf2a4aee-b92e-41d6-187a-08d91c13899d X-MS-TrafficTypeDiagnostic: BY5PR15MB3714: X-Microsoft-Antispam-PRVS: X-FB-Source: Internal X-MS-Oob-TLC-OOBClassifiers: OLM:10000; X-MS-Exchange-SenderADCheck: 1 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:BY5PR15MB3571.namprd15.prod.outlook.com;PTR:;CAT:NONE;SFS:(4636009)(376002)(39860400002)(136003)(396003)(366004)(346002)(86362001)(66946007)(55016002)(316002)(66476007)(66556008)(8676002)(83380400001)(9686003)(6916009)(1076003)(6506007)(7416002)(38100700002)(8936002)(2906002)(5660300002)(52116002)(7696005)(16526019)(186003)(4326008)(478600001);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?lw0i31avZL6p0vazG3Q1MHCZPxFyghQW9OxMUAW2Ozm8CYdGbNF2b7d4GwrR?= =?us-ascii?Q?/IMwkw2guMFT3/C1Ns1fr+EdBSNBBOT2IG5DKJUw072vTbIe7+h3cCBQThcT?= =?us-ascii?Q?sRIUSK9PdfsHB4m1NDl1bTCMvSUgzQvzK/klpHdXl+P545++YQeUt01HCfkS?= =?us-ascii?Q?ox1dTd6RcF80lwTIbd4PbjqKVYBETrbbTcVtcxzNy8Q/61BTNhbpBMhD8BxH?= =?us-ascii?Q?fm+f127L3cElmDhzduiexHt8x+Xarok75wXG1oVq4diNcGDqSifCSBU0wVK0?= =?us-ascii?Q?BMt99ss0xe59omvFbrPJNfrggVmu/vvQvvUwkj7ZbKb0IYclZmsRGEMbmTEk?= =?us-ascii?Q?r285xyvt12yi/jPNE3ZmdeZvDxHIcAi4UWZBri3EzlBuIOg4uunCZYe9H0HE?= =?us-ascii?Q?OENQPtSA//mV+nN273qZgFpgqPpmtSbw6+h+YSe8s4Nsfao2C42vRogCkHoy?= =?us-ascii?Q?8J9stYJLMuUClTic8OBF9uqwKkLBLIv5AxBlHyKFUUJD+CcT5H9JUsxQHO1y?= =?us-ascii?Q?ojbeTcd+uvG42NOtersFMUuBFWh1ZJcYoZyMnlcWnnS3MZAT7MCw9Tr2gd+x?= =?us-ascii?Q?9GZ66AtEhDbwN/jfbno6VZh10Uah2WIshgt/KmxUrfW+8hX5NpMzhp+VvVpk?= =?us-ascii?Q?FDUBkVbH2gKInnihm9VmxseaPfPdYZs92wmRSlNA1vODq3qGC4fDQ1fzTByd?= =?us-ascii?Q?Vo5yxFbCYxcKhCKRROx68UmXce4q3qii7w0DV4TU8RXIIh7HsvfKqxp/ZYk7?= =?us-ascii?Q?AGQrfJH5pJtpqmYV9ooz/4qHNjju2De8g8ECPtyVAnKOc3ZgH6xpCgX+21UD?= =?us-ascii?Q?gK5hej37rctl0MxF/CgZBB/ESjXCURMPJdyOrkT1syEvp42oqDg5/obFvS5V?= =?us-ascii?Q?Ldh2+OTEYgOjvZTBDvY67HQCnTEr8/ofcH+H59tvxgZ5TlfUGjL3z8iRDG5P?= =?us-ascii?Q?qrYGJfQF+1nZxrSKIhPOunPL62VbnHnTnEcU1WkBFvGKNYtsdx56lA9e+vQa?= =?us-ascii?Q?knU7hwDLYCQaq01iSN3XVI0jPmXmIU2pNZwPb70ecnKxXMqUHhq8Tw0TA2Rs?= =?us-ascii?Q?kSp7JKV5ZTQvfsgjsMsQwA8j/GOAh0n3wHngtSLVEQ7V4m0iykWp6YgrAjI2?= =?us-ascii?Q?7rP0GM2AeBYv3LtjaHrI42Vlp71w19LcA/3I4iUa3EyZ72qjtAw/DoM66Ny1?= =?us-ascii?Q?aqgHuuDdAThByPQqlLo8vOfKTWUd4x6nt3vqxvojuurycd74lXDUaJBOKwyR?= =?us-ascii?Q?Nw8Syjtw+GxqQLWVCGRTxZWK7DP87h6oLsN8CBZ0tiX/XYb0CY4BFECEJqnT?= =?us-ascii?Q?XlnoLNR7uEB2Sb/BqZuNfG3y9ms+oX+guKDqqOJuJuiZOQ=3D=3D?= X-MS-Exchange-CrossTenant-Network-Message-Id: cf2a4aee-b92e-41d6-187a-08d91c13899d X-MS-Exchange-CrossTenant-AuthSource: BY5PR15MB3571.namprd15.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 May 2021 04:47:29.1794 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 8ae927fe-1255-47a7-a2af-5f3a069daaa2 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: bFOhTuyp14rqA0cWJf4AD8QunXnhJ9b/RltKHHZpXFKqygi1DFEAg0ntasFxfKMm X-MS-Exchange-Transport-CrossTenantHeadersStamped: BY5PR15MB3714 X-OriginatorOrg: fb.com X-Proofpoint-ORIG-GUID: sNxH1-zCURWUwkznGd4u-8miNPQtYHH4 X-Proofpoint-GUID: sNxH1-zCURWUwkznGd4u-8miNPQtYHH4 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.391,18.0.761 definitions=2021-05-21_02:2021-05-20,2021-05-21 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 clxscore=1015 priorityscore=1501 suspectscore=0 adultscore=0 impostorscore=0 phishscore=0 mlxlogscore=999 bulkscore=0 mlxscore=0 spamscore=0 malwarescore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2104190000 definitions=main-2105210029 X-FB-Internal: deliver Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 21, 2021 at 09:26:39AM +0900, Kuniyuki Iwashima wrote: > From: Martin KaFai Lau > Date: Thu, 20 May 2021 16:39:06 -0700 > > On Fri, May 21, 2021 at 07:54:48AM +0900, Kuniyuki Iwashima wrote: > > > From: Martin KaFai Lau > > > Date: Thu, 20 May 2021 14:22:01 -0700 > > > > On Thu, May 20, 2021 at 05:51:17PM +0900, Kuniyuki Iwashima wrote: > > > > > From: Martin KaFai Lau > > > > > Date: Wed, 19 May 2021 23:26:48 -0700 > > > > > > On Mon, May 17, 2021 at 09:22:50AM +0900, Kuniyuki Iwashima wrote: > > > > > > > > > > > > > +static int reuseport_resurrect(struct sock *sk, struct sock_reuseport *old_reuse, > > > > > > > + struct sock_reuseport *reuse, bool bind_inany) > > > > > > > +{ > > > > > > > + if (old_reuse == reuse) { > > > > > > > + /* If sk was in the same reuseport group, just pop sk out of > > > > > > > + * the closed section and push sk into the listening section. > > > > > > > + */ > > > > > > > + __reuseport_detach_closed_sock(sk, old_reuse); > > > > > > > + __reuseport_add_sock(sk, old_reuse); > > > > > > > + return 0; > > > > > > > + } > > > > > > > + > > > > > > > + if (!reuse) { > > > > > > > + /* In bind()/listen() path, we cannot carry over the eBPF prog > > > > > > > + * for the shutdown()ed socket. In setsockopt() path, we should > > > > > > > + * not change the eBPF prog of listening sockets by attaching a > > > > > > > + * prog to the shutdown()ed socket. Thus, we will allocate a new > > > > > > > + * reuseport group and detach sk from the old group. > > > > > > > + */ > > > > > > For the reuseport_attach_prog() path, I think it needs to consider > > > > > > the reuse->num_closed_socks != 0 case also and that should belong > > > > > > to the resurrect case. For example, when > > > > > > sk_unhashed(sk) but sk->sk_reuseport == 0. > > > > > > > > > > In the path, reuseport_resurrect() is called from reuseport_alloc() only > > > > > if reuse->num_closed_socks != 0. > > > > > > > > > > > > > > > > @@ -92,6 +117,14 @@ int reuseport_alloc(struct sock *sk, bool bind_inany) > > > > > > reuse = rcu_dereference_protected(sk->sk_reuseport_cb, > > > > > > lockdep_is_held(&reuseport_lock)); > > > > > > if (reuse) { > > > > > > + if (reuse->num_closed_socks) { > > > > > > > > > > But, should this be > > > > > > > > > > if (sk->sk_state == TCP_CLOSE && reuse->num_closed_socks) > > > > > > > > > > because we need not allocate a new group when we attach a bpf prog to > > > > > listeners? > > > > The reuseport_alloc() is fine as is. No need to change. > > > > > > I missed sk_unhashed(sk) prevents calling reuseport_alloc() > > > if sk_state == TCP_LISTEN. I'll keep it as is. > > > > > > > > > > > > > > I should have copied reuseport_attach_prog() in the last reply and > > > > commented there instead. > > > > > > > > I meant reuseport_attach_prog() needs a change. In reuseport_attach_prog(), > > > > iiuc, currently passing the "else if (!rcu_access_pointer(sk->sk_reuseport_cb))" > > > > check implies the sk was (and still is) hashed with sk_reuseport enabled > > > > because the current behavior would have set sk_reuseport_cb to NULL during > > > > unhash but it is no longer true now. For example, this will break: > > > > > > > > 1. shutdown(lsk); /* lsk was bound with sk_reuseport enabled */ > > > > 2. setsockopt(lsk, ..., SO_REUSEPORT, &zero, ...); /* disable sk_reuseport */ > > > > 3. setsockopt(lsk, ..., SO_ATTACH_REUSEPORT_EBPF, &prog_fd, ...); > > > > ^---- /* This will work now because sk_reuseport_cb is not NULL. > > > > * However, it shouldn't be allowed. > > > > */ > > > > > > Thank you for explanation, I understood the case. > > > > > > Exactly, I've confirmed that the case succeeded in the setsockopt() and I > > > could change the active listeners' prog via a shutdowned socket. > > > > > > > > > > > > > > I am thinking something like this (uncompiled code): > > > > > > > > int reuseport_attach_prog(struct sock *sk, struct bpf_prog *prog) > > > > { > > > > struct sock_reuseport *reuse; > > > > struct bpf_prog *old_prog; > > > > > > > > if (sk_unhashed(sk)) { > > > > int err; > > > > > > > > if (!sk->sk_reuseport) > > > > return -EINVAL; > > > > > > > > err = reuseport_alloc(sk, false); > > > > if (err) > > > > return err; > > > > } else if (!rcu_access_pointer(sk->sk_reuseport_cb)) { > > > > /* The socket wasn't bound with SO_REUSEPORT */ > > > > return -EINVAL; > > > > } > > > > > > > > /* ... */ > > > > } > > > > > > > > WDYT? > > > > > > I tested this change worked fine. I think this change should be added in > > > reuseport_detach_prog() also. > > > > > > ---8<--- > > > int reuseport_detach_prog(struct sock *sk) > > > { > > > struct sock_reuseport *reuse; > > > struct bpf_prog *old_prog; > > > > > > if (!rcu_access_pointer(sk->sk_reuseport_cb)) > > > return sk->sk_reuseport ? -ENOENT : -EINVAL; > > > ---8<--- > > Right, a quick thought is something like this for detach: > > > > spin_lock_bh(&reuseport_lock); > > reuse = rcu_dereference_protected(sk->sk_reuseport_cb, > > lockdep_is_held(&reuseport_lock)); > > Is this necessary because reuseport_grow() can detach sk? > > if (!reuse) { > spin_unlock_bh(&reuseport_lock); > return -ENOENT; > } Yes, it is needed. Please add a comment for the reuseport_grow() case also. > > Then we can remove rcu_access_pointer() check and move sk_reuseport check > here. Make sense.