On Wed, 2017-09-27 at 05:42 -0700, Eric Dumazet wrote: > Or something cleaner to avoid copy/paste and focus on proper > skb->data[0] access and meaning. > > Thanks. > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index > 3c9985f299503ea65dad7eb3b47e2ab3bef87800..8ddb840687c1bdb24e4182612abc9e362624c3e9 > 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c > @@ -1496,11 +1496,13 @@ static ssize_t tun_get_user(struct tun_struct *tun, > struct tun_file *tfile, > switch (tun->flags & TUN_TYPE_MASK) { > case IFF_TUN: > if (tun->flags & IFF_NO_PI) { > - switch (skb->data[0] & 0xf0) { > - case 0x40: > + u8 ip_proto = skb->len ? (skb->data[0] >> 4) : 0;
And name this variable ip_version ;)