From patchwork Thu Jan 25 02:37:03 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lawrence Brakmo X-Patchwork-Id: 865660 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.b="q2YtplJf"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3zRmQq3tyYz9t34 for ; Thu, 25 Jan 2018 13:37:23 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932969AbeAYChU (ORCPT ); Wed, 24 Jan 2018 21:37:20 -0500 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:50378 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932615AbeAYChR (ORCPT ); Wed, 24 Jan 2018 21:37:17 -0500 Received: from pps.filterd (m0109334.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w0P2WfZY029501 for ; Wed, 24 Jan 2018 18:37:17 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=/hFs5DeElsgX1CUp4RUsDOxsjqTco73dwLFBpZ2M/ek=; b=q2YtplJfnAU7Wmg7qSGGt72iwW1JkNuogY6gZxMjIlxVXXVD3hIH+Ag19Nqae9VKH7cm x4deRwkQPAIMXtIFDL0hUCQjGlNqw5bNrGxiCKrNdao55XXXpSH8DCNB1ooB6Fxmg9Jz iGFYXre8w+oRGLpb3QF0qhc/lNkdzP2S/rQ= Received: from mail.thefacebook.com ([199.201.64.23]) by mx0a-00082601.pphosted.com with ESMTP id 2fq32dgp1s-1 (version=TLSv1 cipher=ECDHE-RSA-AES256-SHA bits=256 verify=NOT) for ; Wed, 24 Jan 2018 18:37:16 -0800 Received: from mx-out.facebook.com (192.168.52.123) by PRN-CHUB13.TheFacebook.com (192.168.16.23) with Microsoft SMTP Server id 14.3.361.1; Wed, 24 Jan 2018 18:37:16 -0800 Received: by dev15893.prn1.facebook.com (Postfix, from userid 10340) id 7EE48C24616; Wed, 24 Jan 2018 18:37:15 -0800 (PST) Smtp-Origin-Hostprefix: dev From: Lawrence Brakmo Smtp-Origin-Hostname: dev15893.prn1.facebook.com To: netdev CC: Kernel Team , Blake Matheny , Alexei Starovoitov , Daniel Borkmann , Eric Dumazet , Neal Cardwell , Yuchung Cheng Smtp-Origin-Cluster: prn1c29 Subject: [PATCH bpf-next v9 03/12] bpf: Make SOCK_OPS_GET_TCP struct independent Date: Wed, 24 Jan 2018 18:37:03 -0800 Message-ID: <20180125023712.3038949-4-brakmo@fb.com> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20180125023712.3038949-1-brakmo@fb.com> References: <20180125023712.3038949-1-brakmo@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-01-24_09:, , signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Changed SOCK_OPS_GET_TCP to SOCK_OPS_GET_FIELD and added 2 arguments so now it can also work with struct sock fields. The first argument is the name of the field in the bpf_sock_ops struct, the 2nd argument is the name of the field in the OBJ struct. Previous: SOCK_OPS_GET_TCP(FIELD_NAME) New: SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ) Where OBJ is either "struct tcp_sock" or "struct sock" (without quotation). BPF_FIELD is the name of the field in the bpf_sock_ops struct and OBJ_FIELD is the name of the field in the OBJ struct. Although the field names are currently the same, the kernel struct names could change in the future and this change makes it easier to support that. Note that adding access to tcp_sock fields in sock_ops programs does not preclude the tcp_sock fields from being removed as long as we are willing to do one of the following: 1) Return a fixed value (e.x. 0 or 0xffffffff), or 2) Make the verifier fail if that field is accessed (i.e. program fails to load) so the user will know that field is no longer supported. Signed-off-by: Lawrence Brakmo --- net/core/filter.c | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 62e7874..dbb6d2f 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4469,11 +4469,11 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, is_fullsock)); break; -/* Helper macro for adding read access to tcp_sock fields. */ -#define SOCK_OPS_GET_TCP(FIELD_NAME) \ +/* Helper macro for adding read access to tcp_sock or sock fields. */ +#define SOCK_OPS_GET_FIELD(BPF_FIELD, OBJ_FIELD, OBJ) \ do { \ - BUILD_BUG_ON(FIELD_SIZEOF(struct tcp_sock, FIELD_NAME) > \ - FIELD_SIZEOF(struct bpf_sock_ops, FIELD_NAME)); \ + BUILD_BUG_ON(FIELD_SIZEOF(OBJ, OBJ_FIELD) > \ + FIELD_SIZEOF(struct bpf_sock_ops, BPF_FIELD)); \ *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF( \ struct bpf_sock_ops_kern, \ is_fullsock), \ @@ -4485,18 +4485,18 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type, struct bpf_sock_ops_kern, sk),\ si->dst_reg, si->src_reg, \ offsetof(struct bpf_sock_ops_kern, sk));\ - *insn++ = BPF_LDX_MEM(FIELD_SIZEOF(struct tcp_sock, \ - FIELD_NAME), si->dst_reg, \ - si->dst_reg, \ - offsetof(struct tcp_sock, FIELD_NAME)); \ + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(OBJ, \ + OBJ_FIELD), \ + si->dst_reg, si->dst_reg, \ + offsetof(OBJ, OBJ_FIELD)); \ } while (0) case offsetof(struct bpf_sock_ops, snd_cwnd): - SOCK_OPS_GET_TCP(snd_cwnd); + SOCK_OPS_GET_FIELD(snd_cwnd, snd_cwnd, struct tcp_sock); break; case offsetof(struct bpf_sock_ops, srtt_us): - SOCK_OPS_GET_TCP(srtt_us); + SOCK_OPS_GET_FIELD(srtt_us, srtt_us, struct tcp_sock); break; } return insn - insn_buf;