From patchwork Thu Nov 19 16:26:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florent Revest X-Patchwork-Id: 11918221 X-Patchwork-Delegate: bpf@iogearbox.net 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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 E2086C64E75 for ; Thu, 19 Nov 2020 16:27:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7E5C322261 for ; Thu, 19 Nov 2020 16:27:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Ec6NYYeS" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728900AbgKSQ1k (ORCPT ); Thu, 19 Nov 2020 11:27:40 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54056 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728905AbgKSQ1i (ORCPT ); Thu, 19 Nov 2020 11:27:38 -0500 Received: from mail-wm1-x341.google.com (mail-wm1-x341.google.com [IPv6:2a00:1450:4864:20::341]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B4993C061A48 for ; Thu, 19 Nov 2020 08:27:37 -0800 (PST) Received: by mail-wm1-x341.google.com with SMTP id 10so7768244wml.2 for ; Thu, 19 Nov 2020 08:27:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=cupBjlguXrCl4ZT1v3zs9G+3ZU+aGNpRnTKwt9ssey4=; b=Ec6NYYeS63zOmWW5s4jQ0VA0BK5/FyqPEgNIfEDWtMD11omBPX2zXZ1Qbk62bSfXej 1abfFXPgm2FZhpzIHEEW4lBVsB2w74f3jX/vM+mIE1mEdNxwfu82OIkbzuyUnd/EfNnI G01b3pfmZhD1qdvhLrM1RDLshAbCliqKSb4nE= 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=cupBjlguXrCl4ZT1v3zs9G+3ZU+aGNpRnTKwt9ssey4=; b=k+ErNrGEyLZzZvmTPMTOP56+IGs4nSYLRVfkZLJ8OhItbNd9mTvC1Fv4ReO9U26IiT T/iayWJXcJLkgNQsQFr8Z+ITuyPNJpQCpsMrGvsXZI29QCe+gr/NHfnWCFFZ1VKC8or3 0uoIxV+1G9awAoXFktUERsD4R9kWy5GhYZMK+H/yQY8uqwn460Iy+6SVDTJZzDwafMrU M4ECaXdbRQMgzUuHtJKGmFokZp0p/Xvoy7dc9UZ+o/VuUV1e1BtZsR4cTYurSmNxZPeK D4N9XSOlwJV/dPt8amTY+zhTWTwPdf7Xs8x9TRbhoKgxOP+3XMeO+kDtFix7qJW/eqTr sRRQ== X-Gm-Message-State: AOAM533ah0tN9XN4En/2j0AbQ8i8RyNUXg4NLxNSR9eCMj/T1Y6vCR9A R460RIlsAxkqo1Og4aDxA9bblqVDWHmBOB/4 X-Google-Smtp-Source: ABdhPJz6+4/1nN99shYibUPJq3+bbKwakw+4YYiqeSuPjaLugrNgNfBAIEyszlLHPcfpw1DUtHwTjQ== X-Received: by 2002:a1c:6557:: with SMTP id z84mr5572401wmb.144.1605803256233; Thu, 19 Nov 2020 08:27:36 -0800 (PST) Received: from revest.zrh.corp.google.com ([2a00:79e0:42:204:f693:9fff:fef4:a569]) by smtp.gmail.com with ESMTPSA id i5sm380061wrw.45.2020.11.19.08.27.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 19 Nov 2020 08:27:35 -0800 (PST) From: Florent Revest To: bpf@vger.kernel.org Cc: viro@zeniv.linux.org.uk, davem@davemloft.net, kuba@kernel.org, ast@kernel.org, daniel@iogearbox.net, kafai@fb.com, yhs@fb.com, andrii@kernel.org, kpsingh@chromium.org, revest@google.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH v2 5/5] bpf: Add an iterator selftest for bpf_sk_storage_get Date: Thu, 19 Nov 2020 17:26:54 +0100 Message-Id: <20201119162654.2410685-5-revest@chromium.org> X-Mailer: git-send-email 2.29.2.299.gdc1121823c-goog In-Reply-To: <20201119162654.2410685-1-revest@chromium.org> References: <20201119162654.2410685-1-revest@chromium.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Florent Revest The eBPF program iterates over all files and tasks. For all socket files, it stores the tgid of the last task it encountered with a handle to that socket. This is a heuristic for finding the "owner" of a socket similar to what's done by lsof, ss, netstat or fuser. Potentially, this information could be used from a cgroup_skb/*gress hook to try to associate network traffic with processes. The test makes sure that a socket it created is tagged with prog_tests's pid. Signed-off-by: Florent Revest --- .../selftests/bpf/prog_tests/bpf_iter.c | 35 +++++++++++++++++++ .../progs/bpf_iter_bpf_sk_storage_helpers.c | 26 ++++++++++++++ 2 files changed, 61 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index bb4a638f2e6f..4d0626003c03 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -975,6 +975,39 @@ static void test_bpf_sk_storage_delete(void) bpf_iter_bpf_sk_storage_helpers__destroy(skel); } +/* The BPF program stores in every socket the tgid of a task owning a handle to + * it. The test verifies that a locally-created socket is tagged with its pid + */ +static void test_bpf_sk_storage_get(void) +{ + struct bpf_iter_bpf_sk_storage_helpers *skel; + int err, map_fd, val = -1; + int sock_fd = -1; + + skel = bpf_iter_bpf_sk_storage_helpers__open_and_load(); + if (CHECK(!skel, "bpf_iter_bpf_sk_storage_helpers__open_and_load", + "skeleton open_and_load failed\n")) + return; + + sock_fd = socket(AF_INET6, SOCK_STREAM, 0); + if (CHECK(sock_fd < 0, "socket", "errno: %d\n", errno)) + goto out; + + do_dummy_read(skel->progs.fill_socket_owners); + + map_fd = bpf_map__fd(skel->maps.sk_stg_map); + + err = bpf_map_lookup_elem(map_fd, &sock_fd, &val); + CHECK(err || val != getpid(), "bpf_map_lookup_elem", + "map value wasn't set correctly (expected %d, got %d, err=%d)\n", + getpid(), val, err); + + if (sock_fd >= 0) + close(sock_fd); +out: + bpf_iter_bpf_sk_storage_helpers__destroy(skel); +} + static void test_bpf_sk_storage_map(void) { DECLARE_LIBBPF_OPTS(bpf_iter_attach_opts, opts); @@ -1131,6 +1164,8 @@ void test_bpf_iter(void) test_bpf_sk_storage_map(); if (test__start_subtest("bpf_sk_storage_delete")) test_bpf_sk_storage_delete(); + if (test__start_subtest("bpf_sk_storage_get")) + test_bpf_sk_storage_get(); if (test__start_subtest("rdonly-buf-out-of-bound")) test_rdonly_buf_out_of_bound(); if (test__start_subtest("buf-neg-offset")) diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_bpf_sk_storage_helpers.c b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_sk_storage_helpers.c index 01ff3235e413..7206fd6f09ab 100644 --- a/tools/testing/selftests/bpf/progs/bpf_iter_bpf_sk_storage_helpers.c +++ b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_sk_storage_helpers.c @@ -21,3 +21,29 @@ int delete_bpf_sk_storage_map(struct bpf_iter__bpf_sk_storage_map *ctx) return 0; } + +SEC("iter/task_file") +int fill_socket_owners(struct bpf_iter__task_file *ctx) +{ + struct task_struct *task = ctx->task; + struct file *file = ctx->file; + struct socket *sock; + int *sock_tgid; + + if (!task || !file || task->tgid != task->pid) + return 0; + + sock = bpf_sock_from_file(file); + if (!sock) + return 0; + + sock_tgid = bpf_sk_storage_get(&sk_stg_map, sock->sk, 0, + BPF_SK_STORAGE_GET_F_CREATE); + if (!sock_tgid) + return 0; + + *sock_tgid = task->tgid; + + return 0; +} +