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=-13.8 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 615DEC433E6 for ; Fri, 19 Feb 2021 09:53:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1370664ECE for ; Fri, 19 Feb 2021 09:53:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230152AbhBSJxC (ORCPT ); Fri, 19 Feb 2021 04:53:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40386 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229720AbhBSJw7 (ORCPT ); Fri, 19 Feb 2021 04:52:59 -0500 Received: from mail-wr1-x42e.google.com (mail-wr1-x42e.google.com [IPv6:2a00:1450:4864:20::42e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E7005C061574 for ; Fri, 19 Feb 2021 01:52:13 -0800 (PST) Received: by mail-wr1-x42e.google.com with SMTP id v15so7303579wrx.4 for ; Fri, 19 Feb 2021 01:52:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=tFX8aTWhVTIHjfxR53xhrBobFiM0bUDGhWKmsxZ7XHw=; b=ZATd1pytikLgXuZ/FsyZ2A8JTf5NObvV8YL5Z2kmrTMVkTR+TNopFPYw9AjyGbLZCB WGFQQA0+cBeaZRfW7CsMVWlmILb82WvGfc4gVLKe9yQwCzimkK7AxG9qetRH5b/ppMdi bmeMTgPEjcgsDl9dRjhkLP24W3vqu9Fg6YCxA= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=tFX8aTWhVTIHjfxR53xhrBobFiM0bUDGhWKmsxZ7XHw=; b=iQzfsDO7htCu+QQ64upMydVXG+vYCbQkDf5gOsDNLdUclQANsgd1L6H2EsUPCqUdfU 2RtHzwwMyIaX3OleyfggxKPRDWGMGl/UbkSNsOvvDKRys7nYSfqaIJFiiHGOe4P3POcL 92vodUNv0lo4dNNH/ioC70Sxg/uO0212b0FAN3dyR8dCLEIQMnnPXIrMmx6lMw2b0+kS DvnRvD3B6AyL610g6UAD9o3HzMtRU3EQNBw1+CYexFaOxpOBzahhnCZ4CZbLonRzcUa0 /88Qm2nv31Rxmsj6Xp00eCIKcevZ3HtvJN1cVcRmYlMA7H60yNjbVi8W2042+qsUStsc qrUw== X-Gm-Message-State: AOAM532k+XfPWXUDUfHvtnL9DK3C3lAy7/xCx5jhHhVUyRrLAY00QKdn c4c3SdNcb/l0XBThu4h16X1HLA== X-Google-Smtp-Source: ABdhPJwaCsjpdUqeufz7LPA/OBZLTbXFaJC5Fz2YFIOLy+dhMtsxy52sIUvhSH6mADYDMwLyYiR/oQ== X-Received: by 2002:a05:6000:1379:: with SMTP id q25mr8008613wrz.89.1613728332670; Fri, 19 Feb 2021 01:52:12 -0800 (PST) Received: from antares.lan (b.3.5.8.9.a.e.c.e.a.6.2.c.1.9.b.f.f.6.2.a.5.a.7.0.b.8.0.1.0.0.2.ip6.arpa. [2001:8b0:7a5a:26ff:b91c:26ae:cea9:853b]) by smtp.gmail.com with ESMTPSA id a21sm13174910wmb.5.2021.02.19.01.52.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Feb 2021 01:52:12 -0800 (PST) From: Lorenz Bauer To: daniel@iogearbox.net, ast@kernel.org, andrii@kernel.org Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, kernel-team@cloudflare.com, Lorenz Bauer Subject: [PATCH bpf-next v2 0/4] Expose network namespace cookies to user space Date: Fri, 19 Feb 2021 09:51:45 +0000 Message-Id: <20210219095149.50346-1-lmb@cloudflare.com> X-Mailer: git-send-email 2.27.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org We're working on a user space control plane for the BPF sk_lookup hook [1]. The hook attaches to a network namespace and allows control over which socket receives a new connection / packet. Roughly, applications can give a socket to our user space component to participate in custom bind semantics. This creates an edge case where an application can provide us with a socket that lives in a different network namespace than our BPF sk_lookup program. We'd like to return an error in this case. Additionally, we have some user space state that is tied to the network namespace. We currently use the inode of the nsfs entry in a directory name, but this is suffers from inode reuse. I'm proposing to fix both of these issues by adding a new SO_NETNS_COOKIE socket option as well as a NS_GET_COOKIE ioctl. Using these we get a stable, unique identifier for a network namespace and check whether a socket belongs to the "correct" namespace. NS_GET_COOKIE could be renamed to NS_GET_NET_COOKIE. I kept the name generic because it seems like other namespace types could benefit from a cookie as well. 1: https://www.kernel.org/doc/html/latest/bpf/prog_sk_lookup.html Changes in v2: - Rebase on top of Eric Dumazet's netns cookie simplification Lorenz Bauer (4): net: add SO_NETNS_COOKIE socket option nsfs: add an ioctl to discover the network namespace cookie tools/testing: add test for NS_GET_COOKIE tools/testing: add a selftest for SO_NETNS_COOKIE arch/alpha/include/uapi/asm/socket.h | 2 + arch/mips/include/uapi/asm/socket.h | 2 + arch/parisc/include/uapi/asm/socket.h | 2 + arch/sparc/include/uapi/asm/socket.h | 2 + fs/nsfs.c | 8 +++ include/uapi/asm-generic/socket.h | 2 + include/uapi/linux/nsfs.h | 2 + net/core/sock.c | 11 ++++ tools/testing/selftests/net/.gitignore | 1 + tools/testing/selftests/net/Makefile | 2 +- tools/testing/selftests/net/config | 1 + tools/testing/selftests/net/so_netns_cookie.c | 61 +++++++++++++++++++ tools/testing/selftests/nsfs/.gitignore | 1 + tools/testing/selftests/nsfs/Makefile | 2 +- tools/testing/selftests/nsfs/config | 1 + tools/testing/selftests/nsfs/netns.c | 57 +++++++++++++++++ 16 files changed, 155 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/net/so_netns_cookie.c create mode 100644 tools/testing/selftests/nsfs/netns.c -- 2.27.0