From patchwork Wed Dec 2 20:55:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florent Revest X-Patchwork-Id: 11947161 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=-20.2 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, 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 CAF73C64E7C for ; Wed, 2 Dec 2020 20:57:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 76E2D22206 for ; Wed, 2 Dec 2020 20:57:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727381AbgLBU5T (ORCPT ); Wed, 2 Dec 2020 15:57:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46684 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729825AbgLBU5S (ORCPT ); Wed, 2 Dec 2020 15:57:18 -0500 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 11F06C061A52 for ; Wed, 2 Dec 2020 12:55:56 -0800 (PST) Received: by mail-wr1-x443.google.com with SMTP id u12so5588413wrt.0 for ; Wed, 02 Dec 2020 12:55:55 -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=7+55Li1wljIgJq9y6JYUOqOaM7Nk4+K54jOzXcb9isA=; b=Qh1X/leCANR8wn9Y1a1/jZVIZw7mZnAK4DAgx+IGy0uqEejiMoY10N2CNcTab9spsb tZrKeb9KGHJCgGbGZ+QtHJ8cJ2opKR+Sa7gfaiBByoMEYliZjdYYF41WwEJM7eBQuWgn HTji9fMxCyWGgBwfPfQeG/fvptde7zwC938ys= 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=7+55Li1wljIgJq9y6JYUOqOaM7Nk4+K54jOzXcb9isA=; b=jrtvwf0M7DqBM9KkTWBXRoYktKkdHPtl9dKbjbiUBB8mylYzig+8zrE/MnZ1nrQyA8 gz7tQOrwwYDVxrKnBaQCZdntheHloTzGcZoMRXAVES7AoE7Exjh56IoIgFZw7+S/uxhR GcywDvKMdSU7RIgvM7WMj+WCulqc8i3tnZj1Ev4CPB8wlJ3rFPGQFuM6XZu9wibIlUX+ PDz61R4aFkdKtAlWuTsvtWkA5C3Ur4OIk9vX2BNviMjfLVANVzrdE0DNesjzMW1lC8Ki BCV515kQ7AeAiHpa7iuxoR+RUX7GJUYEzVbq09lkPxHe4B0lM1NSgJXlo1N9c5rDu9mQ 1rIA== X-Gm-Message-State: AOAM530M2AIegldY6Gxa3wAX2rXXIXV3GrVh8xxrof46EXI6XANCn7FN z3bQRdwgq3tyXPI+aG/Ztlt+oYw0fbxiEA== X-Google-Smtp-Source: ABdhPJxjWTIoKQTMZ9rTmf1IhrFnfhZakrn0nxVXg++9o3dsSDz+HXUN09OA6xYGS71AJtPqxJnw6A== X-Received: by 2002:a5d:4e87:: with SMTP id e7mr5767347wru.352.1606942554339; Wed, 02 Dec 2020 12:55:54 -0800 (PST) Received: from revest.zrh.corp.google.com ([2a00:79e0:42:204:f693:9fff:fef4:a569]) by smtp.gmail.com with ESMTPSA id d2sm3438486wrn.43.2020.12.02.12.55.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 02 Dec 2020 12:55:53 -0800 (PST) From: Florent Revest X-Google-Original-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 bpf-next v4 5/6] bpf: Add an iterator selftest for bpf_sk_storage_get Date: Wed, 2 Dec 2020 21:55:26 +0100 Message-Id: <20201202205527.984965-5-revest@google.com> X-Mailer: git-send-email 2.29.2.454.gaff20da3a2-goog In-Reply-To: <20201202205527.984965-1-revest@google.com> References: <20201202205527.984965-1-revest@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net 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 Acked-by: Yonghong Song Acked-by: Martin KaFai Lau --- .../selftests/bpf/prog_tests/bpf_iter.c | 40 +++++++++++++++++++ .../progs/bpf_iter_bpf_sk_storage_helpers.c | 24 +++++++++++ 2 files changed, 64 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..9336d0f18331 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -975,6 +975,44 @@ static void test_bpf_sk_storage_delete(void) bpf_iter_bpf_sk_storage_helpers__destroy(skel); } +/* This creates a socket and its local storage. It then runs a task_iter BPF + * program that replaces the existing socket local storage with the tgid of the + * only task owning a file descriptor to this socket, this process, prog_tests. + */ +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; + + map_fd = bpf_map__fd(skel->maps.sk_stg_map); + + err = bpf_map_update_elem(map_fd, &sock_fd, &val, BPF_NOEXIST); + if (CHECK(err, "bpf_map_update_elem", "map_update_failed\n")) + goto close_socket; + + do_dummy_read(skel->progs.fill_socket_owner); + + 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); + +close_socket: + 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 +1169,8 @@ 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..dde53df37de8 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 +21,27 @@ int delete_bpf_sk_storage_map(struct bpf_iter__bpf_sk_storage_map *ctx) return 0; } + +SEC("iter/task_file") +int fill_socket_owner(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) + return 0; + + sock = bpf_sock_from_file(file); + if (!sock) + return 0; + + sock_tgid = bpf_sk_storage_get(&sk_stg_map, sock->sk, 0, 0); + if (!sock_tgid) + return 0; + + *sock_tgid = task->tgid; + + return 0; +}