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 <wcang@nav6.org>
Acked-by: Max Krasnyansky <maxk@qualcomm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 0ce07a3..7ab94c8 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -313,6 +313,21 @@
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;
