From: William Tu
> Sent: 05 October 2017 22:21
...
> >> - if (skb->len > dev->mtu) {
> >> + if (skb->len - dev->hard_header_len > dev->mtu) {
> >
> > Can you guarantee that skb->len > dev_hard_header_len?
> > It is probably safer to check skb->len > dev->hard_header_len + dev->mtu
> > since that addition isn't going to overflow.
> Sure, I will fix it.
>
> >
> >> pskb_trim(skb, dev->mtu);
> >> truncate = true;
> >
> > Is that pskb_trim() now truncating to the correct size?
>
> You're right, now I should truncate to (dev->mtu + dev_hard_header_len)
It might be worth caching that length in the dev structure
to avoid the arithmetic on every packet.
David
