From f09f7ee20c867818bacf79426cf491b2749e7eff Mon Sep 17 00:00:00 2001 From: Ang Way Chuang Date: Tue, 17 Jun 2008 21:10:33 -0700 Subject: [PATCH] tun: Proper handling of IPv6 header in tun driver when TUN_NO_PI is set 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. Signed-off-by: Ang Way Chuang Acked-by: Max Krasnyansky Signed-off-by: David S. Miller --- drivers/net/tun.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 0ce07a339c..7ab94c825b 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 = htons(ETH_P_IP); + break; + case 0x60: + pi.proto = 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; -- 2.39.5