On Fri, 2019-10-11 at 10:39 -0700, Samudrala, Sridhar wrote:
>
> On 10/11/2019 9:53 AM, Josh Hunt wrote:
> > Based on a series from Alexander Duyck this change adds UDP segmentation
> > offload support to the i40e driver.
> >
> > CC: Alexander Duyck <alexander.h.du...@intel.com>
> > CC: Willem de Bruijn <will...@google.com>
> > Signed-off-by: Josh Hunt <joh...@akamai.com>
> > ---
> > drivers/net/ethernet/intel/i40e/i40e_main.c | 1 +
> > drivers/net/ethernet/intel/i40e/i40e_txrx.c | 12 +++++++++---
> > 2 files changed, 10 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c
> > b/drivers/net/ethernet/intel/i40e/i40e_main.c
> > index 6031223eafab..56f8c52cbba1 100644
> > --- a/drivers/net/ethernet/intel/i40e/i40e_main.c
> > +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
> > @@ -12911,6 +12911,7 @@ static int i40e_config_netdev(struct i40e_vsi *vsi)
> > NETIF_F_GSO_IPXIP6 |
> > NETIF_F_GSO_UDP_TUNNEL |
> > NETIF_F_GSO_UDP_TUNNEL_CSUM |
> > + NETIF_F_GSO_UDP_L4 |
> > NETIF_F_SCTP_CRC |
> > NETIF_F_RXHASH |
> > NETIF_F_RXCSUM |
> > diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> > b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> > index e3f29dc8b290..b8496037ef7f 100644
> > --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> > +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
> > @@ -2960,10 +2960,16 @@ static int i40e_tso(struct i40e_tx_buffer *first,
> > u8 *hdr_len,
> >
> > /* remove payload length from inner checksum */
> > paylen = skb->len - l4_offset;
> > - csum_replace_by_diff(&l4.tcp->check, (__force __wsum)htonl(paylen));
> >
> > - /* compute length of segmentation header */
> > - *hdr_len = (l4.tcp->doff * 4) + l4_offset;
> > + if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_L4) {
> > + csum_replace_by_diff(&l4.udp->check, (__force
> > __wsum)htonl(paylen));
> > + /* compute length of segmentation header */
> > + *hdr_len = sizeof(*l4.udp) + l4_offset;
> > + } else {
> > + csum_replace_by_diff(&l4.tcp->check, (__force
> > __wsum)htonl(paylen));
> > + /* compute length of segmentation header */
> > + *hdr_len = (l4.tcp->doff * 4) + l4_offset;
> > + }
>
> Is it guaranteed that gso_type can be either UDP or TCP only if we reach
> here? Don't we need to handle the case where it is neither and return
> from this function?
We should only reach here if a supported gso_type value is in the packet,
otherwise we should end up with software segmentation taking care of it
and clearing the gso_size value if I recall correctly.
Otherwise the code should have been checking for non-TCP types ages ago,
and we would have experienced all sorts of bugs.
- Alex
