From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750997Ab3LKFJO (ORCPT ); Wed, 11 Dec 2013 00:09:14 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49861 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750744Ab3LKFJL (ORCPT ); Wed, 11 Dec 2013 00:09:11 -0500 From: Jason Wang To: davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jason Wang , Zhi Yong Wu , "Michael S. Tsirkin" , Vlad Yasevich Subject: [PATCH net V3 1/2] tun: unbreak truncated packet signalling Date: Wed, 11 Dec 2013 13:08:33 +0800 Message-Id: <1386738514-1502-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 6680ec68eff47d36f67b4351bc9836fd6cba9532 (tuntap: hardware vlan tx support) breaks the truncated packet signal by nev return a length greater than iov length in tun_put_user(). This patch fixes by always return the length of packet plus possible vlan header. Caller can detect the truncated packet by comparing the return value and the size of io length. Cc: Zhi Yong Wu Cc: Michael S. Tsirkin Signed-off-by: Vlad Yasevich Signed-off-by: Jason Wang --- Changes from V2: - use "copied" as the variable name instead to be more descriptive Changes from v1: - increase total unconditionally - do not move veth structure out of the vlan handing block --- drivers/net/tun.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e26cbea..7c8343a 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1184,7 +1184,7 @@ static ssize_t tun_put_user(struct tun_struct *tun, { struct tun_pi pi = { 0, skb->protocol }; ssize_t total = 0; - int vlan_offset = 0; + int vlan_offset = 0, copied; if (!(tun->flags & TUN_NO_PI)) { if ((len -= sizeof(pi)) < 0) @@ -1248,6 +1248,8 @@ static ssize_t tun_put_user(struct tun_struct *tun, total += tun->vnet_hdr_sz; } + copied = total; + total += skb->len; if (!vlan_tx_tag_present(skb)) { len = min_t(int, skb->len, len); } else { @@ -1262,24 +1264,24 @@ static ssize_t tun_put_user(struct tun_struct *tun, vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); len = min_t(int, skb->len + VLAN_HLEN, len); + total += VLAN_HLEN; copy = min_t(int, vlan_offset, len); - ret = skb_copy_datagram_const_iovec(skb, 0, iv, total, copy); + ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy); len -= copy; - total += copy; + copied += copy; if (ret || !len) goto done; copy = min_t(int, sizeof(veth), len); - ret = memcpy_toiovecend(iv, (void *)&veth, total, copy); + ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy); len -= copy; - total += copy; + copied += copy; if (ret || !len) goto done; } - skb_copy_datagram_const_iovec(skb, vlan_offset, iv, total, len); - total += len; + skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len); done: tun->dev->stats.tx_packets++; -- 1.8.3.2