From patchwork Tue Jan 26 16:51:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 372220 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=-26.2 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, 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,USER_IN_DEF_DKIM_WL 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 E79C0C433E6 for ; Wed, 27 Jan 2021 10:37:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3E8120789 for ; Wed, 27 Jan 2021 10:37:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S313983AbhAZW6y (ORCPT ); Tue, 26 Jan 2021 17:58:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728752AbhAZRCN (ORCPT ); Tue, 26 Jan 2021 12:02:13 -0500 Received: from mail-pl1-x649.google.com (mail-pl1-x649.google.com [IPv6:2607:f8b0:4864:20::649]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8FC8BC061A86 for ; Tue, 26 Jan 2021 08:51:08 -0800 (PST) Received: by mail-pl1-x649.google.com with SMTP id e3so10050123pls.7 for ; Tue, 26 Jan 2021 08:51:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=FJcc6MaSwZQRYOWrg1XK9d9cSH1sraaN8OpW2J95iRQ=; b=QSkfO0h4d/vctYI3z52+MQly82DrobeOliUI16mTKFwNS9EsEjBU7YOSzIkr1BG7Jz +euw2Fr8jmX5MtDMVJXBsHp/XtSO5LUKZGQiG2TtxCDqF5YiAtXW0OwAtl4meNlw6Bsc 5/+NvZLmB4ulBnxBi+rH/b6gSPuJ0yYgO0pP4LInAgzeKi+e5x/U8PTn8X0YMfyuaCGb vMSLmt6Z/ps7LoVFxJijVY2jLI0Z5AWmTmcmaOzr9En+8DFy1j1rsAYJEqQJGWkuPFta 0s8MUNTm1sqkweir7vwns+3f8vbZ8GKkxrnmdz7EFZzYrIJ7eYlGP4QV+SMO5cGJ8/xv S2Vw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=FJcc6MaSwZQRYOWrg1XK9d9cSH1sraaN8OpW2J95iRQ=; b=YkILtkFbKSdgm58khOTBOJGXKRsXw4CtbPioAgHurr4qvnS/L4HJJdzSBAOq7yA2el IZXLtIkkZfV3tgOuBbSt2YWmqs9dEHhkJkg7o0kfUZO5v7mrFLJ5VWNj6nZECr/sh/YY 8EIJ/cG8+bhQfdJpguoRDrBMqDAXJWmQIiCR3qGTnoptZiM0eu2DcqTEyJG47CvhMpPX xU0gjyRtZI80vBVveCyeo4NYG+VsmfD4eHY0AdFZ5v002ypjf4HC3wVoX1DOrbDkDhAu pXdIsL2hwgH8sdTHsaS6LwdhzWok/49NA4fI+QwU6CnrOMPGWP/jXDi2No7OicW7fZRh 3BVA== X-Gm-Message-State: AOAM530yXJl1Lh0V5q7Wan6cYDIZNcAmY/Q3flVIgCYGNAlgH+XTVuue AlfJggsfr5b6Nb2KAmc1yQQ9Vuzu+IrUK0Zc5aWwpJJdW6kjWJtN3JsPyfHAVeeAM0YZBPQSIGz 4A9qstg/JQgvq6Ce03bmtfy2F5JNHjpfxZDFn8AxuREoQY/KWp3jowg== X-Google-Smtp-Source: ABdhPJwv4t7xSnFbkbrmYAgMUBcmRK0xqfqrObkr8p7LyBbF01J1rr3ChaxGxiUgFcwu+4vxm1aiKnU= Sender: "sdf via sendgmr" X-Received: from sdf2.svl.corp.google.com ([2620:15c:2c4:1:7220:84ff:fe09:7732]) (user=sdf job=sendgmr) by 2002:a62:6047:0:b029:1ac:6091:cf50 with SMTP id u68-20020a6260470000b02901ac6091cf50mr6087096pfb.40.1611679867930; Tue, 26 Jan 2021 08:51:07 -0800 (PST) Date: Tue, 26 Jan 2021 08:51:04 -0800 In-Reply-To: <20210126165104.891536-1-sdf@google.com> Message-Id: <20210126165104.891536-2-sdf@google.com> Mime-Version: 1.0 References: <20210126165104.891536-1-sdf@google.com> X-Mailer: git-send-email 2.30.0.280.ga3ce27912f-goog Subject: [PATCH bpf-next v3 2/2] selftests/bpf: verify that rebinding to port < 1024 from BPF works From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, Stanislav Fomichev , Andrey Ignatov , Martin KaFai Lau Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Return 3 to indicate that permission check for port 111 should be skipped. Cc: Andrey Ignatov Cc: Martin KaFai Lau Signed-off-by: Stanislav Fomichev --- .../selftests/bpf/prog_tests/bind_perm.c | 80 +++++++++++++++++++ tools/testing/selftests/bpf/progs/bind_perm.c | 36 +++++++++ 2 files changed, 116 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/bind_perm.c create mode 100644 tools/testing/selftests/bpf/progs/bind_perm.c diff --git a/tools/testing/selftests/bpf/prog_tests/bind_perm.c b/tools/testing/selftests/bpf/prog_tests/bind_perm.c new file mode 100644 index 000000000000..763de148e511 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/bind_perm.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include "bind_perm.skel.h" + +#include +#include +#include + +static int duration; + +void try_bind(int port, int expected_errno) +{ + struct sockaddr_in sin = {}; + int fd = -1; + + fd = socket(AF_INET, SOCK_STREAM, 0); + if (CHECK(fd < 0, "fd", "errno %d", errno)) + goto close_socket; + + sin.sin_family = AF_INET; + sin.sin_port = htons(port); + + errno = 0; + bind(fd, (struct sockaddr *)&sin, sizeof(sin)); + ASSERT_EQ(errno, expected_errno, "bind"); + +close_socket: + if (fd >= 0) + close(fd); +} + +void cap_net_bind_service(cap_flag_value_t flag) +{ + const cap_value_t cap_net_bind_service = CAP_NET_BIND_SERVICE; + cap_t caps; + + caps = cap_get_proc(); + if (CHECK(!caps, "cap_get_proc", "errno %d", errno)) + goto free_caps; + + if (CHECK(cap_set_flag(caps, CAP_EFFECTIVE, 1, &cap_net_bind_service, + flag), + "cap_set_flag", "errno %d", errno)) + goto free_caps; + + if (CHECK(cap_set_proc(caps), "cap_set_proc", "errno %d", errno)) + goto free_caps; + +free_caps: + if (CHECK(cap_free(caps), "cap_free", "errno %d", errno)) + goto free_caps; +} + +void test_bind_perm(void) +{ + struct bind_perm *skel; + int cgroup_fd; + + cgroup_fd = test__join_cgroup("/bind_perm"); + if (CHECK(cgroup_fd < 0, "cg-join", "errno %d", errno)) + return; + + skel = bind_perm__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel")) + goto close_cgroup_fd; + + skel->links.bind_v4_prog = bpf_program__attach_cgroup(skel->progs.bind_v4_prog, cgroup_fd); + if (!ASSERT_OK_PTR(skel, "bind_v4_prog")) + goto close_skeleton; + + cap_net_bind_service(CAP_CLEAR); + try_bind(110, EACCES); + try_bind(111, 0); + cap_net_bind_service(CAP_SET); + +close_skeleton: + bind_perm__destroy(skel); +close_cgroup_fd: + close(cgroup_fd); +} diff --git a/tools/testing/selftests/bpf/progs/bind_perm.c b/tools/testing/selftests/bpf/progs/bind_perm.c new file mode 100644 index 000000000000..e89bd264ed26 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bind_perm.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include +#include +#include +#include + +SEC("cgroup/bind4") +int bind_v4_prog(struct bpf_sock_addr *ctx) +{ + struct bpf_sock *sk; + __u32 user_ip4; + __u16 user_port; + + sk = ctx->sk; + if (!sk) + return 0; + + if (sk->family != AF_INET) + return 0; + + if (ctx->type != SOCK_STREAM) + return 0; + + /* Return 1 OR'ed with the first bit set to indicate + * that CAP_NET_BIND_SERVICE should be bypassed. + */ + if (ctx->user_port == bpf_htons(111)) + return (1 | 2); + + return 1; +} + +char _license[] SEC("license") = "GPL";