On Mon, Oct 03, 2016 at 11:00:23AM +0200, Olivier Matz wrote:
> +/* When doing TSO, the IP length is not included in the pseudo header
> + * checksum of the packet given to the PMD, but for virtio it is
> + * expected.
> + */
> +static void
> +virtio_tso_fix_cksum(struct rte_mbuf *m)
> +{
> + /* common case: header is not fragmented */
> + if (likely(rte_pktmbuf_data_len(m) >= m->l2_len + m->l3_len +
> + m->l4_len)) {
...
> + /* replace it in the packet */
> + th->cksum = new_cksum;
> + } else {
...
> + /* replace it in the packet */
> + *rte_pktmbuf_mtod_offset(m, uint8_t *,
> + m->l2_len + m->l3_len + 16) = new_cksum.u8[0];
> + *rte_pktmbuf_mtod_offset(m, uint8_t *,
> + m->l2_len + m->l3_len + 17) = new_cksum.u8[1];
> + }
The tcp header will always be in the mbuf, right? Otherwise, you can't
update the cksum field here. What's the point of introducing the "else
clause" then?
--yliu
