From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 57B9F20303 for ; Wed, 3 Jan 2024 22:25:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=meta.com Received: from pps.filterd (m0109333.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 403GiLf3027546 for ; Wed, 3 Jan 2024 14:25:09 -0800 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3vcxn2pph9-9 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 03 Jan 2024 14:25:08 -0800 Received: from twshared24631.38.frc1.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:21d::8) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.34; Wed, 3 Jan 2024 14:24:36 -0800 Received: by devbig019.vll3.facebook.com (Postfix, from userid 137359) id 34A113DF9EC17; Wed, 3 Jan 2024 14:21:42 -0800 (PST) From: Andrii Nakryiko To: , , , , CC: , , Subject: [PATCH bpf-next 29/29] selftests/bpf: add tests for LIBBPF_BPF_TOKEN_PATH envvar Date: Wed, 3 Jan 2024 14:20:34 -0800 Message-ID: <20240103222034.2582628-30-andrii@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240103222034.2582628-1-andrii@kernel.org> References: <20240103222034.2582628-1-andrii@kernel.org> Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-FB-Internal: Safe Content-Type: text/plain X-Proofpoint-ORIG-GUID: WU9Dw1drbU8CeI7ZeCzfevHic0ZpiPP_ X-Proofpoint-GUID: WU9Dw1drbU8CeI7ZeCzfevHic0ZpiPP_ X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2024-01-03_08,2024-01-03_01,2023-05-22_02 Add new subtest validating LIBBPF_BPF_TOKEN_PATH envvar semantics. Extend existing test to validate that LIBBPF_BPF_TOKEN_PATH allows to disable implicit BPF token creation by setting envvar to empty string. Signed-off-by: Andrii Nakryiko --- .../testing/selftests/bpf/prog_tests/token.c | 98 +++++++++++++++++++ 1 file changed, 98 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/token.c b/tools/testi= ng/selftests/bpf/prog_tests/token.c index 003f7c208f4c..1f6aa685e6f7 100644 --- a/tools/testing/selftests/bpf/prog_tests/token.c +++ b/tools/testing/selftests/bpf/prog_tests/token.c @@ -773,6 +773,9 @@ static int userns_obj_priv_btf_success(int mnt_fd) return validate_struct_ops_load(mnt_fd, true /* should succeed */); } =20 +#define TOKEN_ENVVAR "LIBBPF_BPF_TOKEN_PATH" +#define TOKEN_BPFFS_CUSTOM "/bpf-token-fs" + static int userns_obj_priv_implicit_token(int mnt_fd) { LIBBPF_OPTS(bpf_object_open_opts, opts); @@ -795,6 +798,20 @@ static int userns_obj_priv_implicit_token(int mnt_fd= ) if (!ASSERT_OK(err, "move_mount_bpffs")) return -EINVAL; =20 + /* disable implicit BPF token creation by setting + * LIBBPF_BPF_TOKEN_PATH envvar to empty value, load should fail + */ + err =3D setenv(TOKEN_ENVVAR, "", 1 /*overwrite*/); + if (!ASSERT_OK(err, "setenv_token_path")) + return -EINVAL; + skel =3D dummy_st_ops_success__open_and_load(); + if (!ASSERT_ERR_PTR(skel, "obj_token_envvar_disabled_load")) { + unsetenv(TOKEN_ENVVAR); + dummy_st_ops_success__destroy(skel); + return -EINVAL; + } + unsetenv(TOKEN_ENVVAR); + /* now the same struct_ops skeleton should succeed thanks to libppf * creating BPF token from /sys/fs/bpf mount point */ @@ -818,6 +835,76 @@ static int userns_obj_priv_implicit_token(int mnt_fd= ) return 0; } =20 +static int userns_obj_priv_implicit_token_envvar(int mnt_fd) +{ + LIBBPF_OPTS(bpf_object_open_opts, opts); + struct dummy_st_ops_success *skel; + int err; + + /* before we mount BPF FS with token delegation, struct_ops skeleton + * should fail to load + */ + skel =3D dummy_st_ops_success__open_and_load(); + if (!ASSERT_ERR_PTR(skel, "obj_tokenless_load")) { + dummy_st_ops_success__destroy(skel); + return -EINVAL; + } + + /* mount custom BPF FS over custom location, so libbpf can't create + * BPF token implicitly, unless pointed to it through + * LIBBPF_BPF_TOKEN_PATH envvar + */ + rmdir(TOKEN_BPFFS_CUSTOM); + if (!ASSERT_OK(mkdir(TOKEN_BPFFS_CUSTOM, 0777), "mkdir_bpffs_custom")) + goto err_out; + err =3D sys_move_mount(mnt_fd, "", AT_FDCWD, TOKEN_BPFFS_CUSTOM, MOVE_M= OUNT_F_EMPTY_PATH); + if (!ASSERT_OK(err, "move_mount_bpffs")) + goto err_out; + + /* even though we have BPF FS with delegation, it's not at default + * /sys/fs/bpf location, so we still fail to load until envvar is set u= p + */ + skel =3D dummy_st_ops_success__open_and_load(); + if (!ASSERT_ERR_PTR(skel, "obj_tokenless_load2")) { + dummy_st_ops_success__destroy(skel); + goto err_out; + } + + err =3D setenv(TOKEN_ENVVAR, TOKEN_BPFFS_CUSTOM, 1 /*overwrite*/); + if (!ASSERT_OK(err, "setenv_token_path")) + goto err_out; + + /* now the same struct_ops skeleton should succeed thanks to libppf + * creating BPF token from custom mount point + */ + skel =3D dummy_st_ops_success__open_and_load(); + if (!ASSERT_OK_PTR(skel, "obj_implicit_token_load")) + goto err_out; + + dummy_st_ops_success__destroy(skel); + + /* now disable implicit token through empty bpf_token_path, envvar + * will be ignored, should fail + */ + opts.bpf_token_path =3D ""; + skel =3D dummy_st_ops_success__open_opts(&opts); + if (!ASSERT_OK_PTR(skel, "obj_empty_token_path_open")) + goto err_out; + + err =3D dummy_st_ops_success__load(skel); + dummy_st_ops_success__destroy(skel); + if (!ASSERT_ERR(err, "obj_empty_token_path_load")) + goto err_out; + + rmdir(TOKEN_BPFFS_CUSTOM); + unsetenv(TOKEN_ENVVAR); + return 0; +err_out: + rmdir(TOKEN_BPFFS_CUSTOM); + unsetenv(TOKEN_ENVVAR); + return -EINVAL; +} + #define bit(n) (1ULL << (n)) =20 void test_token(void) @@ -896,4 +983,15 @@ void test_token(void) =20 subtest_userns(&opts, userns_obj_priv_implicit_token); } + if (test__start_subtest("obj_priv_implicit_token_envvar")) { + struct bpffs_opts opts =3D { + /* allow BTF loading */ + .cmds =3D bit(BPF_BTF_LOAD) | bit(BPF_MAP_CREATE) | bit(BPF_PROG_LOAD= ), + .maps =3D bit(BPF_MAP_TYPE_STRUCT_OPS), + .progs =3D bit(BPF_PROG_TYPE_STRUCT_OPS), + .attachs =3D ~0ULL, + }; + + subtest_userns(&opts, userns_obj_priv_implicit_token_envvar); + } } --=20 2.34.1