diff mbox series

[v3] app/testpmd: fix TX checksum calculation for tunnel

Message ID 20210729093948.25847-1-getelson@nvidia.com (mailing list archive)
State Superseded, archived
Delegated to: Andrew Rybchenko
Headers show
Series [v3] app/testpmd: fix TX checksum calculation for tunnel | expand

Checks

Context Check Description
ci/iol-testing success Testing PASS
ci/iol-abi-testing success Testing PASS
ci/iol-intel-Performance success Performance Testing PASS
ci/iol-intel-Functional success Functional Testing PASS
ci/intel-Testing success Testing PASS
ci/Intel-compilation success Compilation OK
ci/github-robot success github build: passed
ci/checkpatch success coding style OK

Commit Message

Gregory Etelson July 29, 2021, 9:39 a.m. UTC
csumonly engine calculates TX checksum of a tunnelled packet for outer
headers only or separately for outer and inner headers. The
calculation method is determined by checksum configuration options.
If TX checksum calculation is separated, the inner headers are
processed before outer headers.

Inner headers processing sets checksum values to 0 unconditionally.
If TX configuration offloads inner checksums only, outer checksum
calculation in software will read 0 instead of real values and
produce wrong result.

The patch zeroes inner checksums only before software calculation.

Fixes: 51f694dd40f5 ("app/testpmd: rework checksum forward engine")
Cc: stable@dpdk.org

Signed-off-by: Gregory Etelson <getelson@nvidia.com>
---
v2: 
 remove blank line between Fixes and Cc
 explicitly compare with 0 value in `if ()`
v3:
 update the patch comment  
---
 app/test-pmd/csumonly.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

Comments

Olivier Matz July 29, 2021, 4:05 p.m. UTC | #1
On Thu, Jul 29, 2021 at 12:39:48PM +0300, Gregory Etelson wrote:
> csumonly engine calculates TX checksum of a tunnelled packet for outer
> headers only or separately for outer and inner headers. The
> calculation method is determined by checksum configuration options.
> If TX checksum calculation is separated, the inner headers are
> processed before outer headers.
> 
> Inner headers processing sets checksum values to 0 unconditionally.
> If TX configuration offloads inner checksums only, outer checksum
> calculation in software will read 0 instead of real values and
> produce wrong result.
> 
> The patch zeroes inner checksums only before software calculation.
> 
> Fixes: 51f694dd40f5 ("app/testpmd: rework checksum forward engine")
> Cc: stable@dpdk.org

As said previously, I think the correct Fixes line is:
Fixes: 6b520d54ebfe ("app/testpmd: use Tx preparation in checksum engine")

Acked-by: Olivier Matz <olivier.matz@6wind.com>

Thanks
Gregory Etelson July 29, 2021, 5:05 p.m. UTC | #2
Hello Olivier,

> >
> > Fixes: 51f694dd40f5 ("app/testpmd: rework checksum forward engine")
> > Cc: stable@dpdk.org
> 
> As said previously, I think the correct Fixes line is:
> Fixes: 6b520d54ebfe ("app/testpmd: use Tx preparation in checksum engine")
> 

I updated the Fixes hash in v4.

> Acked-by: Olivier Matz <olivier.matz@6wind.com>
> 
> Thanks
diff mbox series

Patch

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 {
+				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 */
 		}