From patchwork Fri Dec 4 11:36:05 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florent Revest X-Patchwork-Id: 11951527 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, 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 2F2A0C4361A for ; Fri, 4 Dec 2020 11:38:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E0D7122519 for ; Fri, 4 Dec 2020 11:38:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729980AbgLDLhq (ORCPT ); Fri, 4 Dec 2020 06:37:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39026 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729939AbgLDLhq (ORCPT ); Fri, 4 Dec 2020 06:37:46 -0500 Received: from mail-wm1-x344.google.com (mail-wm1-x344.google.com [IPv6:2a00:1450:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92147C061A54 for ; Fri, 4 Dec 2020 03:36:20 -0800 (PST) Received: by mail-wm1-x344.google.com with SMTP id g185so6728231wmf.3 for ; Fri, 04 Dec 2020 03:36:20 -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=qPhKNSKix9ps6GS0Raw6aDVQctcEct9mnWnHTyXi76k=; b=JEnqWT68pY1kg4toeVdhfrjXfne+Ui7JHqPpejXdLFlGT7gSSEsu3kpw/2aF1M3DfY uqJUyQ6NEzWZpwpNERhSh4Oe/B0TExgToeT6XmbSDkBrJ3jbRzMWwrQ+Q2sFVqugne9L vHzCK3QguNO3Om/BH778hCdKpXTIGrOykbD4s= 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=qPhKNSKix9ps6GS0Raw6aDVQctcEct9mnWnHTyXi76k=; b=lNj/yPl098yCjFuB7L3mpp339XYowRAwmtclj1wUPYvp3NwZfqdW+dE7ntKpIlv8WE 4EU5YzVGLlqnUdqVeO6oXjp6M8gmXRsCPNVH4nhcO2kjWjDFNznBKoWoq6CA0bVvPswZ d9t8SK2tZdw+l1cyXhL4RZDtjAUBr2RHeAjAdyPacjG/KvrLT66FRD72DXi2weB/I0qr Ew+BocOw8+4dCH0jgtjNX2b/SdHya/4/wEiaJ2eRzregTGoSBtfgTSOMEmLxrLNIj+H9 1qBhu8+y3o5twKGbTQNuHkBqB3kGAg5RM9mOlYvP+66sjiG2QBZIy+aspajOGHhDB+ms iaaA== X-Gm-Message-State: AOAM530WiyuZlMOe4RUWZCsAc8pc8/iY60gLb+AbjbmhgDYHctoaMimW xn/qgBaW39ZNxqn5pJ3kjCWnuh5C7qSDOg== X-Google-Smtp-Source: ABdhPJymEl3rQhCISYgehOtqbgitdNCnCfKA9TCY4xT32Jm4XK9VGdPnhvCoZglUYlAgZ3ytFojyoQ== X-Received: by 2002:a1c:56c4:: with SMTP id k187mr3725091wmb.92.1607081778960; Fri, 04 Dec 2020 03:36:18 -0800 (PST) Received: from revest.zrh.corp.google.com ([2a00:79e0:42:204:f693:9fff:fef4:a569]) by smtp.gmail.com with ESMTPSA id j6sm3202750wrq.38.2020.12.04.03.36.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Dec 2020 03:36:18 -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, KP Singh Subject: [PATCH bpf-next v5 2/6] bpf: Add a bpf_sock_from_file helper Date: Fri, 4 Dec 2020 12:36:05 +0100 Message-Id: <20201204113609.1850150-2-revest@google.com> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog In-Reply-To: <20201204113609.1850150-1-revest@google.com> References: <20201204113609.1850150-1-revest@google.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net While eBPF programs can check whether a file is a socket by file->f_op == &socket_file_ops, they cannot convert the void private_data pointer to a struct socket BTF pointer. In order to do this a new helper wrapping sock_from_file is added. This is useful to tracing programs but also other program types inheriting this set of helpers such as iterators or LSM programs. Signed-off-by: Florent Revest Acked-by: KP Singh Acked-by: Martin KaFai Lau --- include/uapi/linux/bpf.h | 9 +++++++++ kernel/trace/bpf_trace.c | 20 ++++++++++++++++++++ scripts/bpf_helpers_doc.py | 4 ++++ tools/include/uapi/linux/bpf.h | 9 +++++++++ 4 files changed, 42 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1233f14f659f..30b477a26482 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3822,6 +3822,14 @@ union bpf_attr { * The **hash_algo** is returned on success, * **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if * invalid arguments are passed. + * + * struct socket *bpf_sock_from_file(struct file *file) + * Description + * If the given file represents a socket, returns the associated + * socket. + * Return + * A pointer to a struct socket on success or NULL if the file is + * not a socket. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3986,6 +3994,7 @@ union bpf_attr { FN(bprm_opts_set), \ FN(ktime_get_coarse_ns), \ FN(ima_inode_hash), \ + FN(sock_from_file), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 23a390aac524..acbe76790996 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1260,6 +1260,24 @@ const struct bpf_func_proto bpf_snprintf_btf_proto = { .arg5_type = ARG_ANYTHING, }; +BPF_CALL_1(bpf_sock_from_file, struct file *, file) +{ + return (unsigned long) sock_from_file(file); +} + +BTF_ID_LIST(bpf_sock_from_file_btf_ids) +BTF_ID(struct, socket) +BTF_ID(struct, file) + +static const struct bpf_func_proto bpf_sock_from_file_proto = { + .func = bpf_sock_from_file, + .gpl_only = false, + .ret_type = RET_PTR_TO_BTF_ID_OR_NULL, + .ret_btf_id = &bpf_sock_from_file_btf_ids[0], + .arg1_type = ARG_PTR_TO_BTF_ID, + .arg1_btf_id = &bpf_sock_from_file_btf_ids[1], +}; + const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -1356,6 +1374,8 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_per_cpu_ptr_proto; case BPF_FUNC_bpf_this_cpu_ptr: return &bpf_this_cpu_ptr_proto; + case BPF_FUNC_sock_from_file: + return &bpf_sock_from_file_proto; default: return NULL; } diff --git a/scripts/bpf_helpers_doc.py b/scripts/bpf_helpers_doc.py index 8b829748d488..867ada23281c 100755 --- a/scripts/bpf_helpers_doc.py +++ b/scripts/bpf_helpers_doc.py @@ -437,6 +437,8 @@ class PrinterHelpers(Printer): 'struct path', 'struct btf_ptr', 'struct inode', + 'struct socket', + 'struct file', ] known_types = { '...', @@ -482,6 +484,8 @@ class PrinterHelpers(Printer): 'struct path', 'struct btf_ptr', 'struct inode', + 'struct socket', + 'struct file', } mapped_types = { 'u8': '__u8', diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 1233f14f659f..30b477a26482 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3822,6 +3822,14 @@ union bpf_attr { * The **hash_algo** is returned on success, * **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if * invalid arguments are passed. + * + * struct socket *bpf_sock_from_file(struct file *file) + * Description + * If the given file represents a socket, returns the associated + * socket. + * Return + * A pointer to a struct socket on success or NULL if the file is + * not a socket. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3986,6 +3994,7 @@ union bpf_attr { FN(bprm_opts_set), \ FN(ktime_get_coarse_ns), \ FN(ima_inode_hash), \ + FN(sock_from_file), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper