From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754939AbYFFLgU (ORCPT ); Fri, 6 Jun 2008 07:36:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753197AbYFFLgF (ORCPT ); Fri, 6 Jun 2008 07:36:05 -0400 Received: from mail.nav6.org ([219.93.2.80]:35991 "EHLO nav6.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753235AbYFFLgF (ORCPT ); Fri, 6 Jun 2008 07:36:05 -0400 Message-ID: <59966.10.207.160.229.1212754418.squirrel@nav6.org> Date: Fri, 6 Jun 2008 20:13:38 +0800 (MYT) Subject: [PATCH] NET: Proper handling of IPv6 header in tun driver when TUN_NO_PI is set From: wcang@nav6.org To: netdev@vger.kernel.org, maxk@qualcomm.com Cc: linux-kernel@vger.kernel.org User-Agent: SquirrelMail/1.4.10a MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-Priority: 3 (Normal) Importance: Normal Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org By default, tun.c running in TUN_TUN_DEV mode will set the protocol of packet to IPv4 if TUN_NO_PI is set. My program failed to work when I assumed that the driver will check the first nibble of packet, determine IP version and set the appropriate protocol. The test for this change was conducted on 2.6.24.7 kernel. But the diff is produced using git commit c3b25b32e8bef526cca748e1ba023c6bdd705a99. I couldn't test it on kernel version greater than 2.6.25 due to out of tree driver failing to compile. But tun_get_user doesn't change that much between 2.6.24 and 2.6.26, so it should work, I hope :-D . This patch is trivial because this problem can also be fixed by not using TUN_NO_PI. Signed-off-by: Ang Way Chuang --- diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 0ce07a3..77964bc 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -313,6 +313,21 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, switch (tun->flags & TUN_TYPE_MASK) { case TUN_TUN_DEV: + if (tun->flags & TUN_NO_PI) { + switch (skb->data[0] & 0xf0) { + case 0x40: + pi.proto = __constant_htons(ETH_P_IP); + break; + case 0x60: + pi.proto = __constant_htons(ETH_P_IPV6); + break; + default: + tun->dev->stats.rx_dropped++; + kfree_skb(skb); + return -EINVAL; + } + } + skb_reset_mac_header(skb); skb->protocol = pi.proto; skb->dev = tun->dev; --