From nobody Wed Dec 24 22:08:09 2025 Received: from mail-pj1-f44.google.com (mail-pj1-f44.google.com [209.85.216.44]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 566DF17C6C for ; Wed, 24 Jan 2024 08:58:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.44 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706086720; cv=none; b=aLipYiNJ2jSt0pssNAiQT8bABJroqKgK7oZBocGVY2h4qo7lzlYHtE+YvMvorkDZbaikDQ6enBiEDN9v02FFQl3/EKV0WReeGcFtUKnNl9PW14VDumVSQs/QrtNtULfPd80eK4chCk6kUlzwrW1j5iGGF1V4RoaIg/N5h2Ljuac= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706086720; c=relaxed/simple; bh=og/4jZhQQp7y8j0tIvax0Xzi48W/KUOVqjDS1vcX2Rc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=nH6bxMUXaiEcfz0nEDYt0etljMKnzFmSy7okeveh1xnrWkqK1Ii4FFxC6dlcPnhUw+6mX1ycnJR2JczkCAfCan8oVCKfs0uQT1Ugrrd0377UerMllJ/g3jDdYiOYrUfs5hM4cfIqenTxLUV0YHT21nHo/sZ0vxcRbCp7JoZx4JE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=UwOz4IOU; arc=none smtp.client-ip=209.85.216.44 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UwOz4IOU" Received: by mail-pj1-f44.google.com with SMTP id 98e67ed59e1d1-290617c6200so1974792a91.1 for ; Wed, 24 Jan 2024 00:58:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1706086718; x=1706691518; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=cPu6P60AtBzEJlySRcvQE2oYJV8KpvDM6ODg18dewI4=; b=UwOz4IOUauurk99hSrorKYBvmOgSvFSUIpT+pizqZHVJYVef0mnRfjRr6dhcLR9EI5 8a9cwIhtgp///XId1jBL66nU4UEA/4oiOx73PnCtAoszqLC0B0nyNTOnIWThSthSQdVp w4yR1UVqS3Khoh08Hao7BMSRvAJptk5ZhIEUujKFZs7sdtoDnUWm/5J1BR1cWdJBvDhG d1IynuLpYAgDNi3jjOnJGMgosJix7GB+rvx6CP8XxYWyXnwfHAD5wq87PT6/koahg21C SiWb2jdfHYnNrBiySfnyzq92wUm7zkAIKpoxL4lP/KwCox27W+Vdtlir+4aLpymqp80T l9kw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706086718; x=1706691518; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=cPu6P60AtBzEJlySRcvQE2oYJV8KpvDM6ODg18dewI4=; b=wF19RRXhS/Ri33D3a9fil9lOgQM7SMOsi8KDx5cc6FEmDDuaEm5JerJO51vTftyFhG OlFoDal9cmpCbRIYTeBYtUVnKwWITsH23nM528iLhkpGD4H/JeNdRH5h6so6WH+v7/Rl GnCKhCm9XojH3BJGc5vOjNSiYmjSK2HZblVU2q3FUX2wiNEesApwTenFQCZHYW95Ctfz yj9aJ4nOdh+t2or0cAv/6vG4xCsDlINaYGTMH3FNoQsiV3qghuejLJ7LGAld7QmR1UUG 5PVGCQPJm48E6dxBZL/KZFahy7gg+HE+0SFVulbNY6gC6PKg4qaKPKBAcvvgfVdfbve3 Lnvg== X-Gm-Message-State: AOJu0YxSwZBMk9mwOozTFJuRcbtUC0Uu83YqxrY3uL+YXZ2v+E21Nzf7 tRW2wsRSFw+O1DpoYuO1IneKoMqpAMp0k5c4vhF4AWlR86/uAtVn X-Google-Smtp-Source: AGHT+IGtaFk86gI0X1es3cazO+4bzDFE1/1zDKanQ1edDEL19O1uyHYitentoQwv3rAZxhz4ey3lCw== X-Received: by 2002:a17:90a:ba8a:b0:28e:84eb:2958 with SMTP id t10-20020a17090aba8a00b0028e84eb2958mr3190942pjr.76.1706086718519; Wed, 24 Jan 2024 00:58:38 -0800 (PST) Received: from localhost.localdomain ([107.167.25.130]) by smtp.googlemail.com with ESMTPSA id sb3-20020a17090b50c300b0028ffc524085sm13192233pjb.56.2024.01.24.00.58.35 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Jan 2024 00:58:37 -0800 (PST) From: Liang Chen To: mst@redhat.com, jasowang@redhat.com, hengqi@linux.alibaba.com, xuanzhuo@linux.alibaba.com Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, liangchen.linux@gmail.com Subject: [PATCH v2 1/3] virtio_net: Preserve virtio header before XDP program execution Date: Wed, 24 Jan 2024 16:57:19 +0800 Message-Id: <20240124085721.54442-2-liangchen.linux@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240124085721.54442-1-liangchen.linux@gmail.com> References: <20240124085721.54442-1-liangchen.linux@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The xdp program may overwrite the inline virtio header. To ensure the integrity of the virtio header, it is saved in a data structure that wraps both the xdp_buff and the header before running the xdp program. Signed-off-by: Liang Chen --- drivers/net/virtio_net.c | 43 +++++++++++++++++++++++++++++----------- 1 file changed, 31 insertions(+), 12 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index d7ce4a1011ea..b56828804e5f 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -349,6 +349,11 @@ struct virtio_net_common_hdr { }; }; =20 +struct virtnet_xdp_buff { + struct xdp_buff xdp; + struct virtio_net_common_hdr hdr; +}; + static void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf); =20 static bool is_xdp_frame(void *ptr) @@ -1199,9 +1204,10 @@ static struct sk_buff *receive_small_xdp(struct net_= device *dev, unsigned int headroom =3D vi->hdr_len + header_offset; struct virtio_net_hdr_mrg_rxbuf *hdr =3D buf + header_offset; struct page *page =3D virt_to_head_page(buf); + struct virtnet_xdp_buff virtnet_xdp; struct page *xdp_page; + struct xdp_buff *xdp; unsigned int buflen; - struct xdp_buff xdp; struct sk_buff *skb; unsigned int metasize =3D 0; u32 act; @@ -1233,17 +1239,23 @@ static struct sk_buff *receive_small_xdp(struct net= _device *dev, page =3D xdp_page; } =20 - xdp_init_buff(&xdp, buflen, &rq->xdp_rxq); - xdp_prepare_buff(&xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, + xdp =3D &virtnet_xdp.xdp; + xdp_init_buff(xdp, buflen, &rq->xdp_rxq); + xdp_prepare_buff(xdp, buf + VIRTNET_RX_PAD + vi->hdr_len, xdp_headroom, len, true); =20 - act =3D virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); + /* Copy out the virtio header, as it may be overwritten by the + * xdp program. + */ + memcpy(&virtnet_xdp.hdr, hdr, vi->hdr_len); + + act =3D virtnet_xdp_handler(xdp_prog, xdp, dev, xdp_xmit, stats); =20 switch (act) { case XDP_PASS: /* Recalculate length in case bpf program changed it */ - len =3D xdp.data_end - xdp.data; - metasize =3D xdp.data - xdp.data_meta; + len =3D xdp->data_end - xdp->data; + metasize =3D xdp->data - xdp->data_meta; break; =20 case XDP_TX: @@ -1254,7 +1266,7 @@ static struct sk_buff *receive_small_xdp(struct net_d= evice *dev, goto err_xdp; } =20 - skb =3D virtnet_build_skb(buf, buflen, xdp.data - buf, len); + skb =3D virtnet_build_skb(buf, buflen, xdp->data - buf, len); if (unlikely(!skb)) goto err; =20 @@ -1591,10 +1603,11 @@ static struct sk_buff *receive_mergeable_xdp(struct= net_device *dev, int num_buf =3D virtio16_to_cpu(vi->vdev, hdr->num_buffers); struct page *page =3D virt_to_head_page(buf); int offset =3D buf - page_address(page); + struct virtnet_xdp_buff virtnet_xdp; unsigned int xdp_frags_truesz =3D 0; struct sk_buff *head_skb; unsigned int frame_sz; - struct xdp_buff xdp; + struct xdp_buff *xdp; void *data; u32 act; int err; @@ -1604,16 +1617,22 @@ static struct sk_buff *receive_mergeable_xdp(struct= net_device *dev, if (unlikely(!data)) goto err_xdp; =20 - err =3D virtnet_build_xdp_buff_mrg(dev, vi, rq, &xdp, data, len, frame_sz, + xdp =3D &virtnet_xdp.xdp; + err =3D virtnet_build_xdp_buff_mrg(dev, vi, rq, xdp, data, len, frame_sz, &num_buf, &xdp_frags_truesz, stats); if (unlikely(err)) goto err_xdp; =20 - act =3D virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats); + /* Copy out the virtio header, as it may be overwritten by the + * xdp program. + */ + memcpy(&virtnet_xdp.hdr, hdr, vi->hdr_len); + + act =3D virtnet_xdp_handler(xdp_prog, xdp, dev, xdp_xmit, stats); =20 switch (act) { case XDP_PASS: - head_skb =3D build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz); + head_skb =3D build_skb_from_xdp_buff(dev, vi, xdp, xdp_frags_truesz); if (unlikely(!head_skb)) break; return head_skb; @@ -1626,7 +1645,7 @@ static struct sk_buff *receive_mergeable_xdp(struct n= et_device *dev, break; } =20 - put_xdp_frags(&xdp); + put_xdp_frags(xdp); =20 err_xdp: put_page(page); --=20 2.40.1