[PATCH] net/mlx5: zero encap UDP csum for IPv4 too

[Bing Zhao]

From: Eli Britstein <elibr at nvidia.com>

A zero UDP csum indicates it should not be validated by the receiver.
The HW may not calculate UDP csum after encap.

The cited commit made sure the UDP csum is zero for UDP over IPv6,
mistakenly not handling UDP over IPv4. Fix it.

Fixes: bf1d7d9a033a ("net/mlx5: zero out UDP checksum in encapsulation")
Cc: stable at dpdk.org

Signed-off-by: Eli Britstein <elibr at nvidia.com>
---
 drivers/net/mlx5/mlx5_flow_dv.c | 26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

diff --git a/drivers/net/mlx5/mlx5_flow_dv.c b/drivers/net/mlx5/mlx5_flow_dv.c
index 9753af2cb1..115d730317 100644
--- a/drivers/net/mlx5/mlx5_flow_dv.c
+++ b/drivers/net/mlx5/mlx5_flow_dv.c
@@ -4713,6 +4713,7 @@ flow_dv_zero_encap_udp_csum(void *data, struct rte_flow_error *error)
 {
 	struct rte_ether_hdr *eth = NULL;
 	struct rte_vlan_hdr *vlan = NULL;
+	struct rte_ipv4_hdr *ipv4 = NULL;
 	struct rte_ipv6_hdr *ipv6 = NULL;
 	struct rte_udp_hdr *udp = NULL;
 	char *next_hdr;
@@ -4729,24 +4730,27 @@ flow_dv_zero_encap_udp_csum(void *data, struct rte_flow_error *error)
 		next_hdr += sizeof(struct rte_vlan_hdr);
 	}
 
-	/* HW calculates IPv4 csum. no need to proceed */
-	if (proto == RTE_ETHER_TYPE_IPV4)
-		return 0;
-
 	/* non IPv4/IPv6 header. not supported */
-	if (proto != RTE_ETHER_TYPE_IPV6) {
+	if (proto != RTE_ETHER_TYPE_IPV4 && proto != RTE_ETHER_TYPE_IPV6) {
 		return rte_flow_error_set(error, ENOTSUP,
 					  RTE_FLOW_ERROR_TYPE_ACTION,
 					  NULL, "Cannot offload non IPv4/IPv6");
 	}
 
-	ipv6 = (struct rte_ipv6_hdr *)next_hdr;
-
-	/* ignore non UDP */
-	if (ipv6->proto != IPPROTO_UDP)
-		return 0;
+	if (proto == RTE_ETHER_TYPE_IPV4) {
+		ipv4 = (struct rte_ipv4_hdr *)next_hdr;
+		/* ignore non UDP */
+		if (ipv4->next_proto_id != IPPROTO_UDP)
+			return 0;
+		udp = (struct rte_udp_hdr *)(ipv4 + 1);
+	} else {
+		ipv6 = (struct rte_ipv6_hdr *)next_hdr;
+		/* ignore non UDP */
+		if (ipv6->proto != IPPROTO_UDP)
+			return 0;
+		udp = (struct rte_udp_hdr *)(ipv6 + 1);
+	}
 
-	udp = (struct rte_udp_hdr *)(ipv6 + 1);
 	udp->dgram_cksum = 0;
 
 	return 0;
-- 
2.34.1