From nobody Thu Dec 18 03:54:37 2025 Received: from mail-pl1-f182.google.com (mail-pl1-f182.google.com [209.85.214.182]) (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 626E122A4E4 for ; Wed, 5 Feb 2025 06:23:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738736585; cv=none; b=EJbRuC1FfALlTRGQ65MNafwhNXHIdGfvrCmo+77h/yXG252FueWbKtilKAhBYLyWF4C7yyWvGJ5FFhmWPl2q8GZ0L5IP5DewuWMH838KXDSsyGDa5SgiryVoXfteUabQQWO+P3+TAZ3mI/yXemEOyxLx98y612Y95gl8IUxjee8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738736585; c=relaxed/simple; bh=1kfwXowcu8r3IMQTXe7PLhRBVMfknEmCsLcWG6R/qn8=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=b2eRP32/AJEzufHTh/NknJU/B40fJUIHFLk+BpZ+Z1gSsFoPIPi3UM4B2S/joQWW2SOobb6Ap2bVZ7AOkRf3v34VbceIw2oAfMHnbeuKG1qZmkKUKmb1quacEHa5zLNhD5Jqsypk8cz6fxuOZ4d5wynRlqwsCBcElN4dPuqPfWk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=daynix.com; spf=pass smtp.mailfrom=daynix.com; dkim=pass (2048-bit key) header.d=daynix-com.20230601.gappssmtp.com header.i=@daynix-com.20230601.gappssmtp.com header.b=hEgExfB9; arc=none smtp.client-ip=209.85.214.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=daynix.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=daynix.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=daynix-com.20230601.gappssmtp.com header.i=@daynix-com.20230601.gappssmtp.com header.b="hEgExfB9" Received: by mail-pl1-f182.google.com with SMTP id d9443c01a7336-21effc750d2so26347545ad.3 for ; Tue, 04 Feb 2025 22:23:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=daynix-com.20230601.gappssmtp.com; s=20230601; t=1738736582; x=1739341382; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=EdteCPyxaLnTbFrQqSLEpLkKaGkxVoLiFLjqkZyLOko=; b=hEgExfB9gMwg6CbDpuv+o1DVYjlX8gS6Lj36vYVR5me5hZVwBf1u7P7K24Bggw6I9S YdsD1xSyQ1N9ACfsjx4qn4cL+aR6j9VQQbwht1RxhpJ1Gk/XgTW1GX/vKdYW4+Fn62uE fryC66DA7RJsJaSutSconObDWt3gLOHnB02lF0dLv9Gr/UmyX+9Gokr4d9MvFLVQonBs IiRu0A3AfEGSfkN5HlxtzNi4KIM1Cqpkidufn1Nuuos3vc1IHdbch2tuahAJ6XT1rOVD yoSYg7JFw4bjWFRYYChz6SRxQIpgfBjF61b0SlhdqhLbdw4tt7oMC6PVv/Ni/7cR8JYn +eKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738736582; x=1739341382; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=EdteCPyxaLnTbFrQqSLEpLkKaGkxVoLiFLjqkZyLOko=; b=NNyABe5nk6IL/kSFAU+wzfgLv7lHNQ8SbY2dOGbEvRVmCTXhxL4PoqZiGNVQ1vvYzL ys4G3y0siosK8zshJK8k9s255Dy4zVoNa0SIf8/iOoBwNwMdtxLhRJPLW7qFfCR1jzOC N7lcsGrIcEB7HyzMIhLB/+KaHhZEDoKsxK7zG34VLDdgOC/jXCHEpSjs8NlVpRWadcC5 jPGeufEZ0BYNfdvlbUHKbOSv8ycUMFlHxk2Tgra6oBeZm+1rjV8J+HKbOs0fwGdh31yr 0REL+o7grFmZhwCVvH2KfTnzEFhN9EVdvfg7ExORfjnW4ffqhMGwnWfkUY5T23RBEj7+ iR6Q== X-Forwarded-Encrypted: i=1; AJvYcCX6Y0PEe77fRt1YFw3QxkM8xIX8nEkHX7hxRMv5CTBlKpY/RkLROQCjuQWMvVDzC6OtW/+3koLMAL41fyU=@vger.kernel.org X-Gm-Message-State: AOJu0YxJInMEoR3zj3XQsxfW6xkRIyZS47jlDj2yHlkjm6rh1EPOBWdu XdvIqGlJjHy4Fa0UfdOnjGLHifcs4LxPf9jfjrjj8iK7yKxoRq7+IyN9NAkpb/M= X-Gm-Gg: ASbGncstUUTu2W+Fb8+38f3Y8YBoUWX3PO+dTBIGqUktGxAtKfK4QDRPL7xlz7HYEO4 sYyuJCQChbbxvnRX5LuLeWP62rw0sfvkfCi67MRUxcl/WVQ9EtvJztThNP1nXSx4AI4oXHDD1XJ sWsW7QsjvoMzEcb/JTBKrr9ii6Hl5/sFqcXzamjQl/a7VO8nBwli/1Hk7791wxe3Gp5xMjK0qCc 31j3LlVZMyEJsXp9jLIoLOwreIzOAYb7GxZS7FehFRI01UURsH7UWdLVxdqJ3liSw1OISzsvEiJ gLqIJlrT6O9b+IiBUHc= X-Google-Smtp-Source: AGHT+IGS0p/woIeC+Ecmgux0bdZYtHmzuFlzAKlhJ7xY0Zf9qFKBQod0Xje6b5F5RjRzDrSuFL9Qwg== X-Received: by 2002:a17:903:41cf:b0:215:9d58:6f35 with SMTP id d9443c01a7336-21f17dde0f5mr30415915ad.1.1738736581697; Tue, 04 Feb 2025 22:23:01 -0800 (PST) Received: from localhost ([157.82.207.107]) by smtp.gmail.com with UTF8SMTPSA id d9443c01a7336-21de31f7554sm107377935ad.81.2025.02.04.22.22.56 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 04 Feb 2025 22:23:01 -0800 (PST) From: Akihiko Odaki Date: Wed, 05 Feb 2025 15:22:26 +0900 Subject: [PATCH net-next v5 4/7] tun: Decouple vnet handling Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250205-tun-v5-4-15d0b32e87fa@daynix.com> References: <20250205-tun-v5-0-15d0b32e87fa@daynix.com> In-Reply-To: <20250205-tun-v5-0-15d0b32e87fa@daynix.com> To: Jonathan Corbet , Willem de Bruijn , Jason Wang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Xuan Zhuo , Shuah Khan , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kselftest@vger.kernel.org, Yuri Benditovich , Andrew Melnychenko , Stephen Hemminger , gur.stavi@huawei.com, devel@daynix.com, Akihiko Odaki Cc: Willem de Bruijn X-Mailer: b4 0.14.2 Decouple the vnet handling code so that we can reuse it for tap. Signed-off-by: Akihiko Odaki Reviewed-by: Willem de Bruijn --- drivers/net/tun.c | 237 ++++++++++++++++++++++++++++++++------------------= ---- 1 file changed, 139 insertions(+), 98 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 8ddd4b352f0307e52cdff75254b5ac1d259d51f8..5bd1c21032ed673ba8e39dd5a48= 8cce11599855b 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -351,6 +351,127 @@ static inline __virtio16 cpu_to_tun16(unsigned int fl= ags, u16 val) return __cpu_to_virtio16(tun_is_little_endian(flags), val); } =20 +static long tun_vnet_ioctl(int *vnet_hdr_sz, unsigned int *flags, + unsigned int cmd, int __user *sp) +{ + int s; + + switch (cmd) { + case TUNGETVNETHDRSZ: + s =3D *vnet_hdr_sz; + if (put_user(s, sp)) + return -EFAULT; + return 0; + + case TUNSETVNETHDRSZ: + if (get_user(s, sp)) + return -EFAULT; + if (s < (int)sizeof(struct virtio_net_hdr)) + return -EINVAL; + + *vnet_hdr_sz =3D s; + return 0; + + case TUNGETVNETLE: + s =3D !!(*flags & TUN_VNET_LE); + if (put_user(s, sp)) + return -EFAULT; + return 0; + + case TUNSETVNETLE: + if (get_user(s, sp)) + return -EFAULT; + if (s) + *flags |=3D TUN_VNET_LE; + else + *flags &=3D ~TUN_VNET_LE; + return 0; + + case TUNGETVNETBE: + return tun_get_vnet_be(*flags, sp); + + case TUNSETVNETBE: + return tun_set_vnet_be(flags, sp); + + default: + return -EINVAL; + } +} + +static int tun_vnet_hdr_get(int sz, unsigned int flags, struct iov_iter *f= rom, + struct virtio_net_hdr *hdr) +{ + u16 hdr_len; + + if (iov_iter_count(from) < sz) + return -EINVAL; + + if (!copy_from_iter_full(hdr, sizeof(*hdr), from)) + return -EFAULT; + + hdr_len =3D tun16_to_cpu(flags, hdr->hdr_len); + + if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + hdr_len =3D max(tun16_to_cpu(flags, hdr->csum_start) + tun16_to_cpu(flag= s, hdr->csum_offset) + 2, hdr_len); + hdr->hdr_len =3D cpu_to_tun16(flags, hdr_len); + } + + if (hdr_len > iov_iter_count(from)) + return -EINVAL; + + iov_iter_advance(from, sz - sizeof(*hdr)); + + return hdr_len; +} + +static int tun_vnet_hdr_put(int sz, struct iov_iter *iter, + const struct virtio_net_hdr *hdr) +{ + if (unlikely(iov_iter_count(iter) < sz)) + return -EINVAL; + + if (unlikely(copy_to_iter(hdr, sizeof(*hdr), iter) !=3D sizeof(*hdr))) + return -EFAULT; + + iov_iter_advance(iter, sz - sizeof(*hdr)); + + return 0; +} + +static int tun_vnet_hdr_to_skb(unsigned int flags, struct sk_buff *skb, + const struct virtio_net_hdr *hdr) +{ + return virtio_net_hdr_to_skb(skb, hdr, tun_is_little_endian(flags)); +} + +static int tun_vnet_hdr_from_skb(unsigned int flags, + const struct net_device *dev, + const struct sk_buff *skb, + struct virtio_net_hdr *hdr) +{ + int vlan_hlen =3D skb_vlan_tag_present(skb) ? VLAN_HLEN : 0; + + if (virtio_net_hdr_from_skb(skb, hdr, + tun_is_little_endian(flags), true, + vlan_hlen)) { + struct skb_shared_info *sinfo =3D skb_shinfo(skb); + + if (net_ratelimit()) { + netdev_err(dev, "unexpected GSO type: 0x%x, gso_size %d, hdr_len %d\n", + sinfo->gso_type, tun16_to_cpu(flags, hdr->gso_size), + tun16_to_cpu(flags, hdr->hdr_len)); + print_hex_dump(KERN_ERR, "tun: ", + DUMP_PREFIX_NONE, + 16, 1, skb->head, + min(tun16_to_cpu(flags, hdr->hdr_len), 64), true); + } + WARN_ON_ONCE(1); + return -EINVAL; + } + + return 0; +} + static inline u32 tun_hashfn(u32 rxhash) { return rxhash & TUN_MASK_FLOW_ENTRIES; @@ -1764,25 +1885,12 @@ static ssize_t tun_get_user(struct tun_struct *tun,= struct tun_file *tfile, =20 if (tun->flags & IFF_VNET_HDR) { int vnet_hdr_sz =3D READ_ONCE(tun->vnet_hdr_sz); - int flags =3D tun->flags; - - if (len < vnet_hdr_sz) - return -EINVAL; - len -=3D vnet_hdr_sz; - - if (!copy_from_iter_full(&gso, sizeof(gso), from)) - return -EFAULT; - - hdr_len =3D tun16_to_cpu(flags, gso.hdr_len); =20 - if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { - hdr_len =3D max(tun16_to_cpu(flags, gso.csum_start) + tun16_to_cpu(flag= s, gso.csum_offset) + 2, hdr_len); - gso.hdr_len =3D cpu_to_tun16(flags, hdr_len); - } + hdr_len =3D tun_vnet_hdr_get(vnet_hdr_sz, tun->flags, from, &gso); + if (hdr_len < 0) + return hdr_len; =20 - if (hdr_len > len) - return -EINVAL; - iov_iter_advance(from, vnet_hdr_sz - sizeof(gso)); + len -=3D vnet_hdr_sz; } =20 if ((tun->flags & TUN_TYPE_MASK) =3D=3D IFF_TAP) { @@ -1856,7 +1964,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, s= truct tun_file *tfile, } } =20 - if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun->flags))) { + if (tun_vnet_hdr_to_skb(tun->flags, skb, &gso)) { atomic_long_inc(&tun->rx_frame_errors); err =3D -EINVAL; goto free_skb; @@ -2051,18 +2159,15 @@ static ssize_t tun_put_user_xdp(struct tun_struct *= tun, { int vnet_hdr_sz =3D 0; size_t size =3D xdp_frame->len; - size_t ret; + ssize_t ret; =20 if (tun->flags & IFF_VNET_HDR) { struct virtio_net_hdr gso =3D { 0 }; =20 vnet_hdr_sz =3D READ_ONCE(tun->vnet_hdr_sz); - if (unlikely(iov_iter_count(iter) < vnet_hdr_sz)) - return -EINVAL; - if (unlikely(copy_to_iter(&gso, sizeof(gso), iter) !=3D - sizeof(gso))) - return -EFAULT; - iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso)); + ret =3D tun_vnet_hdr_put(vnet_hdr_sz, iter, &gso); + if (ret) + return ret; } =20 ret =3D copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz; @@ -2085,6 +2190,7 @@ static ssize_t tun_put_user(struct tun_struct *tun, int vlan_offset =3D 0; int vlan_hlen =3D 0; int vnet_hdr_sz =3D 0; + int ret; =20 if (skb_vlan_tag_present(skb)) vlan_hlen =3D VLAN_HLEN; @@ -2110,33 +2216,14 @@ static ssize_t tun_put_user(struct tun_struct *tun, =20 if (vnet_hdr_sz) { struct virtio_net_hdr gso; - int flags =3D tun->flags; - - if (iov_iter_count(iter) < vnet_hdr_sz) - return -EINVAL; - - if (virtio_net_hdr_from_skb(skb, &gso, - tun_is_little_endian(flags), true, - vlan_hlen)) { - struct skb_shared_info *sinfo =3D skb_shinfo(skb); - - if (net_ratelimit()) { - netdev_err(tun->dev, "unexpected GSO type: 0x%x, gso_size %d, hdr_len = %d\n", - sinfo->gso_type, tun16_to_cpu(flags, gso.gso_size), - tun16_to_cpu(flags, gso.hdr_len)); - print_hex_dump(KERN_ERR, "tun: ", - DUMP_PREFIX_NONE, - 16, 1, skb->head, - min((int)tun16_to_cpu(flags, gso.hdr_len), 64), true); - } - WARN_ON_ONCE(1); - return -EINVAL; - } =20 - if (copy_to_iter(&gso, sizeof(gso), iter) !=3D sizeof(gso)) - return -EFAULT; + ret =3D tun_vnet_hdr_from_skb(tun->flags, tun->dev, skb, &gso); + if (ret) + return ret; =20 - iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso)); + ret =3D tun_vnet_hdr_put(vnet_hdr_sz, iter, &gso); + if (ret) + return ret; } =20 if (vlan_hlen) { @@ -2496,7 +2583,7 @@ static int tun_xdp_one(struct tun_struct *tun, skb_reserve(skb, xdp->data - xdp->data_hard_start); skb_put(skb, xdp->data_end - xdp->data); =20 - if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun->flags))) { + if (tun_vnet_hdr_to_skb(tun->flags, skb, gso)) { atomic_long_inc(&tun->rx_frame_errors); kfree_skb(skb); ret =3D -EINVAL; @@ -3080,8 +3167,6 @@ static long __tun_chr_ioctl(struct file *file, unsign= ed int cmd, kgid_t group; int ifindex; int sndbuf; - int vnet_hdr_sz; - int le; int ret; bool do_notify =3D false; =20 @@ -3288,50 +3373,6 @@ static long __tun_chr_ioctl(struct file *file, unsig= ned int cmd, tun_set_sndbuf(tun); break; =20 - case TUNGETVNETHDRSZ: - vnet_hdr_sz =3D tun->vnet_hdr_sz; - if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz))) - ret =3D -EFAULT; - break; - - case TUNSETVNETHDRSZ: - if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) { - ret =3D -EFAULT; - break; - } - if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) { - ret =3D -EINVAL; - break; - } - - tun->vnet_hdr_sz =3D vnet_hdr_sz; - break; - - case TUNGETVNETLE: - le =3D !!(tun->flags & TUN_VNET_LE); - if (put_user(le, (int __user *)argp)) - ret =3D -EFAULT; - break; - - case TUNSETVNETLE: - if (get_user(le, (int __user *)argp)) { - ret =3D -EFAULT; - break; - } - if (le) - tun->flags |=3D TUN_VNET_LE; - else - tun->flags &=3D ~TUN_VNET_LE; - break; - - case TUNGETVNETBE: - ret =3D tun_get_vnet_be(tun->flags, argp); - break; - - case TUNSETVNETBE: - ret =3D tun_set_vnet_be(&tun->flags, argp); - break; - case TUNATTACHFILTER: /* Can be set only for TAPs */ ret =3D -EINVAL; @@ -3387,7 +3428,7 @@ static long __tun_chr_ioctl(struct file *file, unsign= ed int cmd, break; =20 default: - ret =3D -EINVAL; + ret =3D tun_vnet_ioctl(&tun->vnet_hdr_sz, &tun->flags, cmd, argp); break; } =20 --=20 2.48.1