Hello,
Please see below.
Regards,
Gregory
> > Subject: [PATCH v2] app/testpmd: fix TX checksum calculation for
> > tunnel
> >
> > TX checksum of a tunnelled packet can be calculated for outer headers
> > only or for both outer and inner parts. The calculation method is
> > determined by application.
> > If TX checksum calculation can be offloaded, hardware ignores existing
> > checksum value and replaces it with an updated result.
> > If TX checksum is calculated by a software, existing value must be zeroed
> first.
> > The testpmd checksum forwarding engine always zeroed inner checksums.
> > If inner checksum calculation was offloaded, that header was left with
> > 0 checksum value.
> > Following outer software checksum calculation produced wrong value.
> > The patch zeroes inner IPv4 checksum only before software calculation.
> >
> > Fixes: 51f694dd40f5 ("app/testpmd: rework checksum forward engine")
> > Cc: sta...@dpdk.org
> >
> > Signed-off-by: Gregory Etelson <getel...@nvidia.com>
> > ---
> > v2:
> > remove blank line between Fixes and Cc explicitly compare with 0
> > value in `if ()`
> > ---
> > app/test-pmd/csumonly.c | 23 ++++++++++++-----------
> > 1 file changed, 12 insertions(+), 11 deletions(-)
> >
> > diff --git a/app/test-pmd/csumonly.c b/app/test-pmd/csumonly.c index
> > 0161f72175..bd5ad64a57 100644
> > --- a/app/test-pmd/csumonly.c
> > +++ b/app/test-pmd/csumonly.c
> > @@ -480,17 +480,18 @@ process_inner_cksums(void *l3_hdr, const struct
> > testpmd_offload_info *info,
> >
> > if (info->ethertype == _htons(RTE_ETHER_TYPE_IPV4)) {
> > ipv4_hdr = l3_hdr;
> > - ipv4_hdr->hdr_checksum = 0;
> >
> > ol_flags |= PKT_TX_IPV4;
> > if (info->l4_proto == IPPROTO_TCP && tso_segsz) {
> > ol_flags |= PKT_TX_IP_CKSUM;
> > } else {
> > - if (tx_offloads & DEV_TX_OFFLOAD_IPV4_CKSUM)
> > + if (tx_offloads & DEV_TX_OFFLOAD_IPV4_CKSUM) {
> > ol_flags |= PKT_TX_IP_CKSUM;
> > - else
> > + } else if (ipv4_hdr->hdr_checksum != 0) {
> > + ipv4_hdr->hdr_checksum = 0;
> > ipv4_hdr->hdr_checksum =
> > rte_ipv4_cksum(ipv4_hdr);
> > + }
> > }
> > } else if (info->ethertype == _htons(RTE_ETHER_TYPE_IPV6))
> > ol_flags |= PKT_TX_IPV6; @@ -501,10 +502,10 @@
> > process_inner_cksums(void *l3_hdr, const struct testpmd_offload_info
> > *info,
> > udp_hdr = (struct rte_udp_hdr *)((char *)l3_hdr +
> > info->l3_len);
> > /* do not recalculate udp cksum if it was 0 */
> > if (udp_hdr->dgram_cksum != 0) {
> > - udp_hdr->dgram_cksum = 0;
> > - if (tx_offloads & DEV_TX_OFFLOAD_UDP_CKSUM)
> > + if (tx_offloads & DEV_TX_OFFLOAD_UDP_CKSUM) {
> > ol_flags |= PKT_TX_UDP_CKSUM;
> > - else {
> > + } else {
>
> else if (udp_hdr->dgram_cksum != 0) { ?
>
process_inner_cksums() function verifies udp_hdr->dgram_cksum != 0
before checking for hardware / software offload capabilities in enclosing
if() statement. No need to repeat that verification
> > + udp_hdr->dgram_cksum = 0;
> > udp_hdr->dgram_cksum =
> > get_udptcp_checksum(l3_hdr, udp_hdr,
> > info->ethertype); @@
> > -514,12 +515,12 @@ process_inner_cksums(void *l3_hdr, const struct
> > testpmd_offload_info *info,
> > ol_flags |= PKT_TX_UDP_SEG;
> > } else if (info->l4_proto == IPPROTO_TCP) {
> > tcp_hdr = (struct rte_tcp_hdr *)((char *)l3_hdr +
> > info->l3_len);
> > - tcp_hdr->cksum = 0;
> > if (tso_segsz)
> > ol_flags |= PKT_TX_TCP_SEG;
> > - else if (tx_offloads & DEV_TX_OFFLOAD_TCP_CKSUM)
> > + else if (tx_offloads & DEV_TX_OFFLOAD_TCP_CKSUM) {
> > ol_flags |= PKT_TX_TCP_CKSUM;
> > - else {
> > + } else if (tcp_hdr->cksum != 0) {
> > + tcp_hdr->cksum = 0;
> > tcp_hdr->cksum =
> > get_udptcp_checksum(l3_hdr, tcp_hdr,
> > info->ethertype); @@ -529,13
> > +530,13 @@ process_inner_cksums(void *l3_hdr, const struct
> > testpmd_offload_info *info,
> > } else if (info->l4_proto == IPPROTO_SCTP) {
> > sctp_hdr = (struct rte_sctp_hdr *)
> > ((char *)l3_hdr + info->l3_len);
> > - sctp_hdr->cksum = 0;
> > /* sctp payload must be a multiple of 4 to be
> > * offloaded */
> > if ((tx_offloads & DEV_TX_OFFLOAD_SCTP_CKSUM) &&
> > ((ipv4_hdr->total_length & 0x3) == 0)) {
> > ol_flags |= PKT_TX_SCTP_CKSUM;
> > - } else {
> > + } else if (sctp_hdr->cksum != 0) {
> > + sctp_hdr->cksum = 0;
> > /* XXX implement CRC32c, example available in
> > * RFC3309 */
> > }
> > --
> > 2.32.0
