From patchwork Thu May 14 01:50:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Ignatov X-Patchwork-Id: 1289829 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=quarantine dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.a=rsa-sha256 header.s=facebook header.b=Bc9nsHAw; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 49MvdV5lVHz9sSs for ; Thu, 14 May 2020 11:50:54 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728292AbgENBuy (ORCPT ); Wed, 13 May 2020 21:50:54 -0400 Received: from mx0a-00082601.pphosted.com ([67.231.145.42]:48192 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725925AbgENBuy (ORCPT ); Wed, 13 May 2020 21:50:54 -0400 Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 04E1ix6c018810 for ; Wed, 13 May 2020 18:50:53 -0700 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-transfer-encoding : content-type; s=facebook; bh=QrbLMJEK5d+YH3aJxVI0M4vvJ2h6iagiVRe9tWU77+I=; b=Bc9nsHAwAgfZmol1gW4CM6s8xNWdcNq14MVRdsydJtjuKAD8P++XCWcnqnNN1YcW4G+k OaP2lp/sQAP5mCK4H6DjN6ywJGMl51mYVO9reJ+skBnuhHR8JUAk3X663DtF6mcwLyYD lrKzTlzb8QRdePiCUdnI+lNw1CWv4b1Nd2k= Received: from maileast.thefacebook.com ([163.114.130.16]) by mx0a-00082601.pphosted.com with ESMTP id 3100wy8nfw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Wed, 13 May 2020 18:50:53 -0700 Received: from intmgw001.06.prn3.facebook.com (2620:10d:c0a8:1b::d) by mail.thefacebook.com (2620:10d:c0a8:83::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1847.3; Wed, 13 May 2020 18:50:51 -0700 Received: by dev082.prn2.facebook.com (Postfix, from userid 572249) id E4F1F3700963; Wed, 13 May 2020 18:50:47 -0700 (PDT) Smtp-Origin-Hostprefix: dev From: Andrey Ignatov Smtp-Origin-Hostname: dev082.prn2.facebook.com To: CC: Andrey Ignatov , , , Smtp-Origin-Cluster: prn2c23 Subject: [PATCH bpf-next 1/2] bpf: Support narrow loads from bpf_sock_addr.user_port Date: Wed, 13 May 2020 18:50:27 -0700 Message-ID: X-Mailer: git-send-email 2.24.1 In-Reply-To: References: MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216, 18.0.676 definitions=2020-05-13_09:2020-05-13,2020-05-13 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 suspectscore=13 priorityscore=1501 mlxscore=0 adultscore=0 mlxlogscore=999 cotscore=-2147483648 impostorscore=0 spamscore=0 lowpriorityscore=0 clxscore=1015 bulkscore=0 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2005140014 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org bpf_sock_addr.user_port supports only 4-byte load and it leads to ugly code in BPF programs, like: volatile __u32 user_port = ctx->user_port; __u16 port = bpf_ntohs(user_port); Since otherwise clang may optimize the load to be 2-byte and it's rejected by verifier. Add support for 1- and 2-byte loads same way as it's supported for other fields in bpf_sock_addr like user_ip4, msg_src_ip4, etc. Signed-off-by: Andrey Ignatov Acked-by: Yonghong Song --- include/uapi/linux/bpf.h | 2 +- net/core/filter.c | 15 +++++++-------- tools/include/uapi/linux/bpf.h | 2 +- 3 files changed, 9 insertions(+), 10 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index bfb31c1be219..85cfdffde182 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3728,7 +3728,7 @@ struct bpf_sock_addr { __u32 user_ip6[4]; /* Allows 1,2,4,8-byte read and 4,8-byte write. * Stored in network byte order. */ - __u32 user_port; /* Allows 4-byte read and write. + __u32 user_port; /* Allows 1,2,4-byte read and 4-byte write. * Stored in network byte order */ __u32 family; /* Allows 4-byte read, but no write */ diff --git a/net/core/filter.c b/net/core/filter.c index da0634979f53..1fe8c0c2d408 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -7029,6 +7029,7 @@ static bool sock_addr_is_valid_access(int off, int size, case bpf_ctx_range(struct bpf_sock_addr, msg_src_ip4): case bpf_ctx_range_till(struct bpf_sock_addr, msg_src_ip6[0], msg_src_ip6[3]): + case bpf_ctx_range(struct bpf_sock_addr, user_port): if (type == BPF_READ) { bpf_ctx_record_field_size(info, size_default); @@ -7059,10 +7060,6 @@ static bool sock_addr_is_valid_access(int off, int size, return false; } break; - case bpf_ctx_range(struct bpf_sock_addr, user_port): - if (size != size_default) - return false; - break; case offsetof(struct bpf_sock_addr, sk): if (type != BPF_READ) return false; @@ -7958,8 +7955,8 @@ static u32 sock_addr_convert_ctx_access(enum bpf_access_type type, struct bpf_insn *insn_buf, struct bpf_prog *prog, u32 *target_size) { + int off, port_size = sizeof_field(struct sockaddr_in6, sin6_port); struct bpf_insn *insn = insn_buf; - int off; switch (si->off) { case offsetof(struct bpf_sock_addr, user_family): @@ -7994,9 +7991,11 @@ static u32 sock_addr_convert_ctx_access(enum bpf_access_type type, offsetof(struct sockaddr_in6, sin6_port)); BUILD_BUG_ON(sizeof_field(struct sockaddr_in, sin_port) != sizeof_field(struct sockaddr_in6, sin6_port)); - SOCK_ADDR_LOAD_OR_STORE_NESTED_FIELD(struct bpf_sock_addr_kern, - struct sockaddr_in6, uaddr, - sin6_port, tmp_reg); + /* Account for sin6_port being smaller than user_port. */ + port_size = min(port_size, BPF_LDST_BYTES(si)); + SOCK_ADDR_LOAD_OR_STORE_NESTED_FIELD_SIZE_OFF( + struct bpf_sock_addr_kern, struct sockaddr_in6, uaddr, + sin6_port, bytes_to_bpf_size(port_size), 0, tmp_reg); break; case offsetof(struct bpf_sock_addr, family): diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index bfb31c1be219..85cfdffde182 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3728,7 +3728,7 @@ struct bpf_sock_addr { __u32 user_ip6[4]; /* Allows 1,2,4,8-byte read and 4,8-byte write. * Stored in network byte order. */ - __u32 user_port; /* Allows 4-byte read and write. + __u32 user_port; /* Allows 1,2,4-byte read and 4-byte write. * Stored in network byte order */ __u32 family; /* Allows 4-byte read, but no write */