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 1F94A1DA56 for ; Wed, 3 Jan 2024 22:24:38 +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 (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 403GiMJw020349 for ; Wed, 3 Jan 2024 14:24:37 -0800 Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 3vda7m2yym-5 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 03 Jan 2024 14:24:37 -0800 Received: from twshared24631.38.frc1.facebook.com (2620:10d:c085:208::11) by mail.thefacebook.com (2620:10d:c085:11d::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 263ED3DF9EC0F; Wed, 3 Jan 2024 14:21:40 -0800 (PST) From: Andrii Nakryiko To: , , , , CC: , , Subject: [PATCH bpf-next 28/29] libbpf: support BPF token path setting through LIBBPF_BPF_TOKEN_PATH envvar Date: Wed, 3 Jan 2024 14:20:33 -0800 Message-ID: <20240103222034.2582628-29-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-GUID: G6XrLQIUPU0Zndssl7Ky-4XnNlLmPy1f X-Proofpoint-ORIG-GUID: G6XrLQIUPU0Zndssl7Ky-4XnNlLmPy1f 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 To allow external admin authority to override default BPF FS location (/sys/fs/bpf) for implicit BPF token creation, teach libbpf to recognize LIBBPF_BPF_TOKEN_PATH envvar. If it is specified and user application didn't explicitly specify bpf_token_path option, it will be treated exactly like bpf_token_path option, overriding default /sys/fs/bpf location and making BPF token mandatory. Suggested-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko --- tools/lib/bpf/libbpf.c | 6 ++++++ tools/lib/bpf/libbpf.h | 8 ++++++++ 2 files changed, 14 insertions(+) diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 69d87d743557..85d6ac99ce01 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -7172,6 +7172,12 @@ static struct bpf_object *bpf_object_open(const ch= ar *path, const void *obj_buf, return ERR_PTR(-EINVAL); =20 token_path =3D OPTS_GET(opts, bpf_token_path, NULL); + /* if user didn't specify bpf_token_path explicitly, check if + * LIBBPF_BPF_TOKEN_PATH envvar was set and treat it as bpf_token_path + * option + */ + if (!token_path) + token_path =3D getenv("LIBBPF_BPF_TOKEN_PATH"); if (token_path && strlen(token_path) >=3D PATH_MAX) return ERR_PTR(-ENAMETOOLONG); =20 diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 535ae15ed493..5723cbbfcc41 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -183,6 +183,14 @@ struct bpf_object_open_opts { * that accept BPF token (e.g., map creation, BTF and program loads, * etc) automatically within instantiated BPF object. * + * If bpf_token_path is not specified, libbpf will consult + * LIBBPF_BPF_TOKEN_PATH environment variable. If set, it will be + * taken as a value of bpf_token_path option and will force libbpf to + * either create BPF token from provided custom BPF FS path, or will + * disable implicit BPF token creation, if envvar value is an empty + * string. bpf_token_path overrides LIBBPF_BPF_TOKEN_PATH, if both are + * set at the same time. + * * Setting bpf_token_path option to empty string disables libbpf's * automatic attempt to create BPF token from default BPF FS mount * point (/sys/fs/bpf), in case this default behavior is undesirable. --=20 2.34.1