From patchwork Wed Jul 22 06:45:56 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrii Nakryiko X-Patchwork-Id: 1333574 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=reject 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=mK8LWSkA; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BBQwT2wy6z9sPB for ; Wed, 22 Jul 2020 16:46:17 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730012AbgGVGqR (ORCPT ); Wed, 22 Jul 2020 02:46:17 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:6410 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726736AbgGVGqQ (ORCPT ); Wed, 22 Jul 2020 02:46:16 -0400 Received: from pps.filterd (m0109331.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 06M6iF1l030667 for ; Tue, 21 Jul 2020 23:46:15 -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=mnUWFvYznG9wK8cawsa8jNN7a+b37lwDfmulrDY5Ej8=; b=mK8LWSkAaxnnlzNVgGW5aALzXuf1NrX7lpg7lth65IGL5YwGmPWmkNrsIHVazqIIfIhn ZQicleA18CwLQhq95j1o4RYzTyF4JA9WNM8GVLUSFDFxUi+9vJhcKRgMSUgpA9SABkH+ ai7EMC1Ns6pVMUE6b2ir1TR1sayvpmhm7lI= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 32bxwfypuv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Tue, 21 Jul 2020 23:46:15 -0700 Received: from intmgw002.03.ash8.facebook.com (2620:10d:c085:208::f) by mail.thefacebook.com (2620:10d:c085:11d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1979.3; Tue, 21 Jul 2020 23:46:13 -0700 Received: by devbig012.ftw2.facebook.com (Postfix, from userid 137359) id 050282EC494E; Tue, 21 Jul 2020 23:46:10 -0700 (PDT) Smtp-Origin-Hostprefix: devbig From: Andrii Nakryiko Smtp-Origin-Hostname: devbig012.ftw2.facebook.com To: , , , , CC: , , Andrii Nakryiko Smtp-Origin-Cluster: ftw2c04 Subject: [PATCH v4 bpf-next 3/9] bpf, xdp: extract common XDP program attachment logic Date: Tue, 21 Jul 2020 23:45:56 -0700 Message-ID: <20200722064603.3350758-4-andriin@fb.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200722064603.3350758-1-andriin@fb.com> References: <20200722064603.3350758-1-andriin@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.235, 18.0.687 definitions=2020-07-22_03:2020-07-22,2020-07-22 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 suspectscore=8 bulkscore=0 spamscore=0 mlxscore=0 malwarescore=0 priorityscore=1501 mlxlogscore=999 phishscore=0 adultscore=0 impostorscore=0 clxscore=1015 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2006250000 definitions=main-2007220049 X-FB-Internal: deliver Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Further refactor XDP attachment code. dev_change_xdp_fd() is split into two parts: getting bpf_progs from FDs and attachment logic, working with bpf_progs. This makes attachment logic a bit more straightforward and prepares code for bpf_xdp_link inclusion, which will share the common logic. Signed-off-by: Andrii Nakryiko --- net/core/dev.c | 165 +++++++++++++++++++++++++++---------------------- 1 file changed, 91 insertions(+), 74 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index 7e753e248cef..abf573b2dcf4 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -8815,111 +8815,128 @@ static void dev_xdp_uninstall(struct net_device *dev) } } -/** - * dev_change_xdp_fd - set or clear a bpf program for a device rx path - * @dev: device - * @extack: netlink extended ack - * @fd: new program fd or negative value to clear - * @expected_fd: old program fd that userspace expects to replace or clear - * @flags: xdp-related flags - * - * Set or clear a bpf program for a device - */ -int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack, - int fd, int expected_fd, u32 flags) +static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack, + struct bpf_prog *new_prog, struct bpf_prog *old_prog, + u32 flags) { - const struct net_device_ops *ops = dev->netdev_ops; - enum bpf_xdp_mode mode = dev_xdp_mode(flags); - bool offload = mode == XDP_MODE_HW; - u32 prog_id, expected_id = 0; - struct bpf_prog *prog; + struct bpf_prog *cur_prog; + enum bpf_xdp_mode mode; bpf_op_t bpf_op; int err; ASSERT_RTNL(); - bpf_op = dev_xdp_bpf_op(dev, mode); - if (!bpf_op) { - NL_SET_ERR_MSG(extack, "underlying driver does not support XDP in native mode"); - return -EOPNOTSUPP; + /* just one XDP mode bit should be set, zero defaults to SKB mode */ + if (hweight32(flags & XDP_FLAGS_MODES) > 1) { + NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set"); + return -EINVAL; + } + /* old_prog != NULL implies XDP_FLAGS_REPLACE is set */ + if (old_prog && !(flags & XDP_FLAGS_REPLACE)) { + NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified"); + return -EINVAL; } - prog_id = dev_xdp_prog_id(dev, mode); - if (flags & XDP_FLAGS_REPLACE) { - if (expected_fd >= 0) { - prog = bpf_prog_get_type_dev(expected_fd, - BPF_PROG_TYPE_XDP, - bpf_op == ops->ndo_bpf); - if (IS_ERR(prog)) - return PTR_ERR(prog); - expected_id = prog->aux->id; - bpf_prog_put(prog); - } - - if (prog_id != expected_id) { - NL_SET_ERR_MSG(extack, "Active program does not match expected"); - return -EEXIST; - } + mode = dev_xdp_mode(flags); + cur_prog = dev_xdp_prog(dev, mode); + if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) { + NL_SET_ERR_MSG(extack, "Active program does not match expected"); + return -EEXIST; } - if (fd >= 0) { + if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) { + NL_SET_ERR_MSG(extack, "XDP program already attached"); + return -EBUSY; + } + + if (new_prog) { + bool offload = mode == XDP_MODE_HW; enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB ? XDP_MODE_DRV : XDP_MODE_SKB; - if (!offload && dev_xdp_prog_id(dev, other_mode)) { + if (!offload && dev_xdp_prog(dev, other_mode)) { NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time"); return -EEXIST; } - - if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && prog_id) { - NL_SET_ERR_MSG(extack, "XDP program already attached"); - return -EBUSY; - } - - prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP, - bpf_op == ops->ndo_bpf); - if (IS_ERR(prog)) - return PTR_ERR(prog); - - if (!offload && bpf_prog_is_dev_bound(prog->aux)) { + if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) { NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported"); - bpf_prog_put(prog); return -EINVAL; } - - if (prog->expected_attach_type == BPF_XDP_DEVMAP) { + if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) { NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device"); - bpf_prog_put(prog); return -EINVAL; } - - if (prog->expected_attach_type == BPF_XDP_CPUMAP) { - NL_SET_ERR_MSG(extack, - "BPF_XDP_CPUMAP programs can not be attached to a device"); - bpf_prog_put(prog); + if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) { + NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device"); return -EINVAL; } + } - /* prog->aux->id may be 0 for orphaned device-bound progs */ - if (prog->aux->id && prog->aux->id == prog_id) { - bpf_prog_put(prog); - return 0; + /* don't call drivers if the effective program didn't change */ + if (new_prog != cur_prog) { + bpf_op = dev_xdp_bpf_op(dev, mode); + if (!bpf_op) { + NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode"); + return -EOPNOTSUPP; } - } else { - if (!prog_id) - return 0; - prog = NULL; - } - err = dev_xdp_install(dev, mode, bpf_op, extack, flags, prog); - if (err < 0 && prog) { - bpf_prog_put(prog); - return err; + err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog); + if (err) + return err; } - dev_xdp_set_prog(dev, mode, prog); + + dev_xdp_set_prog(dev, mode, new_prog); + if (cur_prog) + bpf_prog_put(cur_prog); return 0; } +/** + * dev_change_xdp_fd - set or clear a bpf program for a device rx path + * @dev: device + * @extack: netlink extended ack + * @fd: new program fd or negative value to clear + * @expected_fd: old program fd that userspace expects to replace or clear + * @flags: xdp-related flags + * + * Set or clear a bpf program for a device + */ +int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack, + int fd, int expected_fd, u32 flags) +{ + enum bpf_xdp_mode mode = dev_xdp_mode(flags); + struct bpf_prog *new_prog = NULL, *old_prog = NULL; + int err; + + ASSERT_RTNL(); + + if (fd >= 0) { + new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP, + mode != XDP_MODE_SKB); + if (IS_ERR(new_prog)) + return PTR_ERR(new_prog); + } + + if (expected_fd >= 0) { + old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP, + mode != XDP_MODE_SKB); + if (IS_ERR(old_prog)) { + err = PTR_ERR(old_prog); + old_prog = NULL; + goto err_out; + } + } + + err = dev_xdp_attach(dev, extack, new_prog, old_prog, flags); + +err_out: + if (err && new_prog) + bpf_prog_put(new_prog); + if (old_prog) + bpf_prog_put(old_prog); + return err; +} + /** * dev_new_index - allocate an ifindex * @net: the applicable net namespace